Effective removal of effluent organic matter (EfOM) from bio-treated coking wastewater by a recyclable aminated hyper-cross-linked polymer.

PubMed

Yang, Wenlan; Li, Xuchun; Pan, Bingcai; Lv, Lu; Zhang, Weiming

2013-09-01

Effluent organic matter (EfOM) is a complex matrix of organic substance mainly from bio-treated sewage effluent and is considered as the main constraint to further advanced treatment. Here a recyclable aminated hyper-cross-linked polymeric adsorbent (NDA-802) featured with aminated functional groups, large specific surface area, and sufficient micropore region was synthesized for effective removal of EfOM from the bio-treated coking wastewater (BTCW), and its removal characteristics was investigated. It was found that hydrophobic fraction was the main constituent (64.8% of DOC) in EfOM of BTCW, and the hydrophobic-neutral fraction had the highest SUVA level (7.06 L mg(-1) m(-1)), which were significantly different from that in the domestic wastewater. Column adsorption experiments showed that NDA-802 exhibited much higher removal efficiency of EfOM than other polymeric adsorbents D-301, XAD-4, and XAD-7, and the efficiency could be readily sustained according to continuous 28-cycle batch adsorption-regeneration experiments. Moreover, dissolved organic matter (DOM) fractionation and excitation-emission matrix (EEM) fluorescence spectroscopy study indicated that NDA-802 showed attractive adsorption preference as well as high removal efficiency of hydrophobic and aromatic compounds. Possibly ascribed to the presence of functional aminated groups, relatively large specific surface area and micropore region of the unique polymer, NDA-802 possesses high and sustained efficiency for the removal of EfOM, and provides a potential alternative for the advanced treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

NASA Astrophysics Data System (ADS)

Maeng, Sung Kyu; Sharma, Saroj K.; Abel, Chol D. T.; Magic-Knezev, Aleksandra; Song, Kyung-Guen; Amy, Gary L.

2012-10-01

Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM.

Degradation of dye Procion Red MX-5B by electrolytic and electro-irradiated technologies using diamond electrodes.

PubMed

Cotillas, Salvador; Clematis, Davide; Cañizares, Pablo; Carpanese, Maria Paola; Rodrigo, Manuel A; Panizza, Marco

2018-05-01

This work focuses on the treatment of synthetic wastewater polluted with dye Procion Red MX-5B by different Electrochemical Advanced Oxidation Processes (EAOP) based on diamond anodes. The influence of the current density and the supporting electrolyte has been studied on dye removal and total mineralization of the organic matter. Results show that electrolysis with diamond electrodes is a suitable technology for an efficient degradation of dye. Nonetheless, the process efficiency increases when using chloride as supporting electrolyte because of the electrochemical generation of hypochlorite in wastewater which significantly contribute to dye removal. On the contrary, the total mineralization of the organic matter is more efficient in sulfate media. In this case, large amounts of peroxodisulfate are electrogenerated, favoring the complete removal of total organic carbon (TOC). On the other hand, lower current densities (10 mA cm -2 ) lead to a more efficient removal of both dye and TOC due to the mass transfer limitations of the technology. Finally, the coupling of UV light irradiation or ultrasound to electrolysis significantly improves the process performance, being photoelectrolysis the most efficient technology for the treatment of wastewater polluted with Procion Red MX-5B. This fact is due to the potential production of free chlorine or sulfate radicals that takes place by the activation of the electrogenerated oxidants. These species are more reactive than oxidants and, therefore, they quickly attack the organic matter present in wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

The efficiency of macroporous polystyrene ion-exchange resins in natural organic matter removal from surface water

NASA Astrophysics Data System (ADS)

Urbanowska, Agnieszka; Kabsch-Korbutowicz, Małgorzata

2017-11-01

Natural water sources used for water treatment contains various organic and inorganic compounds. Surface waters are commonly contaminated with natural organic matter (NOM). NOM removal from water is important e.g. due to lowering the risk of disinfection by-product formation during chlorination. Ion exchange with the use of synthetic ion-exchange resins is an alternative process to typical NOM removal approach (e.g. coagulation, adsorption or oxidation) as most NOM compounds have anionic character. Moreover, neutral fraction could be removed from water due to its adsorption on resin surface. In this study, applicability of two macroporous, polystyrene ion exchange resins (BD400FD and A100) in NOM removal from water was assessed including comparison of treatment efficiency in various process set-ups and conditions. Moreover, resin regeneration effectivity was determined. Obtained results shown that examined resins could be applied in NOM removal and it should be noticed that column set-up yielded better results (contrary to batch set-up). Among the examined resins A100 one possessed better properties. It was determined that increase of solution pH resulted in a slight decrease in treatment efficiency while higher temperature improved it. It was also observed that regeneration efficiency was comparable in both tested methods but batch set-up required less reagents.

Simultaneous removal of dissolved organic matter and bromide from drinking water source by anion exchange resins for controlling disinfection by-products.

PubMed

Phetrak, Athit; Lohwacharin, Jenyuk; Sakai, Hiroshi; Murakami, Michio; Oguma, Kumiko; Takizawa, Satoshi

2014-06-01

Anion exchange resins (AERs) with different properties were evaluated for their ability to remove dissolved organic matter (DOM) and bromide, and to reduce disinfection by-product (DBP) formation potentials of water collected from a eutrophic surface water source in Japan. DOM and bromide were simultaneously removed by all selected AERs in batch adsorption experiments. A polyacrylic magnetic ion exchange resin (MIEX®) showed faster dissolved organic carbon (DOC) removal than other AERs because it had the smallest resin bead size. Aromatic DOM fractions with molecular weight larger than 1600 Da and fluorescent organic fractions of fulvic acid- and humic acid-like compounds were efficiently removed by all AERs. Polystyrene AERs were more effective in bromide removal than polyacrylic AERs. This result implied that the properties of AERs, i.e. material and resin size, influenced not only DOM removal but also bromide removal efficiency. MIEX® showed significant chlorinated DBP removal because it had the highest DOC removal within 30 min, whereas polystyrene AERs efficiently removed brominated DBPs, especially brominated trihalomethane species. The results suggested that, depending on source water DOM and bromide concentration, selecting a suitable AER is a key factor in effective control of chlorinated and brominated DBPs in drinking water. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

[Coagulation and adsorption on treating the Yellow River and the impact on chlorine decay during chlorination process].

PubMed

Zhan, Xiao; Gao, Bao-yu; Liu, Bin; Xu, Chun-hua; Yue, Qin-yan

2010-05-01

Two types of inorganic polymer coagulants, polyferric chloride (PFC) and polyaluminum chloride (PAC), were chosen to treat the Yellow River water. Different dosages were investigated in order to investigate the turbidity, UV24, DOC and permanganate index removal efficiency and their coagulation mechanisms based on the Zeta potentials. The natural organic matter removal by the combination of coagulation and adsorption with powder activated carbon were analyzed based on different coagulant and adsorbent dosages and dosing orders. The effects of combination of coagulation and adsorption on the residual chlorine decay were analyzed. The results showed that the two coagulants had high turbidity removal efficiency ( > 90%). The UV254, DOC, permanganate index removal efficiency were 29.2%, 26.1% and 27.9% respectively for PAC coagulation and were 32.3%, 23.3% and 32.9% respectively for PFC. Electric neutralization played an important role in the PAC coagulation process while both adsorption bridging and electric neutralization performed when PFC was used. The removal percentage of organic matter increased with the increase coagulant and adsorbent. The adsorption after coagulation process gave the better UV254 and DOC removal efficiency than the coagulation after adsorption. The UV254 and DOC removal efficiency were 95.2% and 99.9% for PAC coagulation after adsorption and were 90.1% and 99.9% for PFC coagulation first. But adding powder activated carbon can improve floc settlement performance and maintained persistent disinfection effect.

Indicator pathogens, organic matter and LAS detergent removal from wastewater by constructed subsurface wetlands

PubMed Central

2014-01-01

Background Constructed wetland is one of the natural methods of municipal and industrial wastewater treatments with low initial costs for construction and operation as well as easy maintenance. The main objective of this study is to determine the values of indicator bacteria removal, organic matter, TSS, ammonia and nitrate affecting the wetland removal efficiency. Results The average concentration of E. coli and total coliform in the input is 1.127 × 1014 and 4.41 × 1014 MPN/100 mL that reached 5.03 × 1012 and 1.13 × 1014 MPN/100 mL by reducing 95.5% and 74.4% in wetland 2. Fecal streptococcus reached from the average 5.88 × 1014 in raw wastewater to 9.69 × 1012 in the output of wetland 2. Wetland 2 could reduce 1.5 logarithmic units of E. coli. The removal efficiency of TSS for the wetlands is 68.87%, 71.4%, 57.3%, and 66% respectively. Conclusions The overall results show that wetlands in which herbs were planted had a high removal efficiency about the indicator pathogens, organic matter, LAS detergent in comparison to a control wetland (without canes) and could improve physicochemical parameters (DO, ammonia, nitrate, electrical conductivity, and pH) of wastewater. PMID:24581277

Impact of the air filtration on indoor particle concentration by using combination filters in offices building

NASA Astrophysics Data System (ADS)

Kabrein, H.; Hariri, A.; Leman, A. M.; Noraini, N. M. R.; Yusof, M. Z. M.; Afandi, A.

2017-09-01

Heating ventilation and air conditioning system (HVAC) is very important for offices building and human health. The combining filter method was used to reduce the air pollution indoor such as that particulate matter and gases pollution that affected in health and productivity. Using particle filters in industrial HVAC systems (factories and manufacturing process) does not enough to remove all the indoor pollution. The main objective of this study is to investigate the impact of combination filters for particle and gases removal efficiency. The combining method is by using two filters (particulate filter pre-filter and carbon filter) to reduce particle matter and gases respectively. The purpose of this study is to use minimum efficiency reporting value (MERV filter) rating 13 and activated carbon filter (ACF) to remove indoor air pollution and controlling the air change rate to enhance the air quality and energy saving. It was concluded that the combination filter showed good removal efficiency of particle up to 90.76% and 89.25% for PM10 and PM2.5 respectively. The pressure drop across the filters was small compared with the high-efficiency filters. The filtration efficiency of combination filters after three months’ was better than efficiency by the new MERV filter alone.

The removal of organic precursors of DBPs during three advanced water treatment processes including ultrafiltration, biofiltration, and ozonation.

PubMed

Zha, Xiao-Song; Ma, Lu-Ming; Wu, Jin; Liu, Yan

2016-08-01

The removal efficiency of organic matter, the formation potential of trihalomethanes (THMFP), and the formation potential of haloacetic acids (HAAFP) in each unit of three advanced treatment processes were investigated in this paper. The molecular weight distribution and the components of organic matter in water samples were also determined to study the transformation of organic matter during these advanced treatments. Low-molecular-weight matter was the predominant fraction in raw water, and it could not be removed effectively by ultrafiltration and biofiltration. The dominant species of disinfection by-product formation potential (DBPFP) in raw water were chloroform and monochloroacetic acid (MCAA), with average concentrations of 107.3 and 125.9 μg/L, respectively. However, the formation potential of chloroform and MCAA decreased to 36.2 and 11.5 μg/L after ultrafiltration. Similarly, biological pretreatment obtained high removal efficiency for DBPFP. The total THMFP decreased from 173.8 to 81.8 μg/L, and the total HAAFP decreased from 211.9 to 84.2 μg/L. Separate ozonation had an adverse effect on DBPFP, especially for chlorinated HAAFP. Numerous low-molecular-weight compounds such as aldehydes, ketones, and alcohols were generated during the ozonation, which have been proven to be important precursors of HAAs. However, the ozonation/biological activated carbon (BAC) combined process had a better removal efficiency for DBPFP. The total DBPFP decreased remarkably from 338.7 to 113.3 μg/L after the O3/BAC process, far below the separated BAC of process B (189.1 μg/L).

Removal efficiency of particulate matters at different underlying surfaces in Beijing.

PubMed

Liu, Jiakai; Mo, Lichun; Zhu, Lijuan; Yang, Yilian; Liu, Jiatong; Qiu, Dongdong; Zhang, Zhenming; Liu, Jinglan

2016-01-01

Particulate matter (PM) pollution has been increasingly becoming serious in Beijing and has drawn the attention of the local government and general public. This study was conducted during early spring of 2013 and 2014 to monitor the concentration of PM at three different land surfaces (bare land, urban forest, and lake) in the Olympic Park in Beijing and to analyze its effect on the concentration of meteorological factors and the dry deposition onto different land cover types. The results showed that diurnal variation of PM concentrations at the three different land surfaces had no significant regulations, and sharp short-term increases in PM10 (particulate matter having an aerodynamic diameter <10 μm) occurred occasionally. The concentrations also differed from one land cover type to another at the same time, but the regulation was insignificant. The most important meteorological factor influencing the PM concentration is relative humidity; it is positively correlated with the PM concentration. While in the forests, the wind speed and irradiance also influenced the PM concentration by affecting the capture capacity of trees and dry deposition velocity. Other factors were not correlated with or influenced by the PM concentration. In addition, the hourly dry deposition in unit area (μg/m(2)) onto the three types of land surfaces and the removal efficiency based on the ratio of dry deposition and PM concentration were calculated. The results showed that the forest has the best removal capacity for both PM2.5 (particulate matter having an aerodynamic diameter <2.5 μm) and PM10 because of the faster deposition velocity and relatively low resuspension rate. The lake's PM10 removal efficiency is higher than that of the bare land because of the relatively higher PM resuspension rates on the bare land. However, the PM2.5 removal efficiency is lower than that of the bare land because of the significantly lower dry deposition velocity.

Data on performance of air stripping tower- PAC integrated system for removing of odor, taste, dye and organic materials from drinking water-A case study in Saqqez, Iran.

PubMed

Pirsaheb, Meghdad; Mohammadi, Jalil; Khosravi, Touba; Sharafi, Hooshmnd; Moradi, Masoud

2018-06-01

Unpleasant taste or smell are more importantly constituents of drinking-water, lead to complaints from consumers. Dye and organic matter as well change in disinfection practice may generate taste and an odorous compound in treated water. According to low efficiency of conventional methods to remove taste and odor compounds, present study was aimed to evaluate the performance of air stripping tower- Poly Aluminum Chloride (PAC) integrated system to remove odor and taste, dye and organic materials from drinking water. Different air to water ratio and PAC doses were used to remove considered parameters in certain condition. The results of this study indicated that the maximum removal efficiency of 86.2, 76.47, 58.46 and 41.27% of taste and odor, dye, COD and TOC were achieved by the air stripping tower- PAC integrated system, respectively. However, the physico-chemical characteristics of water and adsorbent effect on the of substances removal efficiency considerably. It can be stated that the air striping tower - PAC integrated system is able to reduce the odor and taste-causing substances and organic matter to a level which is recommended by the Institute of Standards and Industrial Research of Iran.

Sorption of pharmaceuticals to soil organic matter in a constructed wetland by electrostatic interaction.

PubMed

Park, Jongkwan; Cho, Kyung Hwa; Lee, Eunkyung; Lee, Sungyun; Cho, Jaeweon

2018-09-01

There is a growing interest in the removal of pharmaceuticals from wastewater because pharmaceuticals have potential ecotoxicological effects. Among several removal mechanisms, the sorption of pharmaceuticals to sediment organic matter is an important mechanism related to the mobility of pharmaceuticals. This study investigated the sorption of pharmaceuticals to soil organic matter (SOM) by electrostatic interactions. SOM located on the surface of soil/sediment generally has a negative charge because of the functional groups present (i.e., carboxylic and phenolic groups). Thus, the electrical characteristics of SOM can induce electrical attraction with positively charged chemical compounds. In this study, SOM was extracted from soils under different aquatic plants (Acorus and Typha) in a constructed wetland in Korea. Experiments were carried out with the following three pharmaceuticals with different electrical characteristics at pH 7: atenolol (positive charge; pKa 9.5), carbamazepine (neutral; no pKa), and ibuprofen (negative charge; pKa 4.9). The SOM in the Acorus pond had a higher hydrophobicity and electrical charge density than that in the Typha pond. Regarding the sorption efficiency between SOM and charged pharmaceuticals, atenolol showed highest sorption efficiency (~60%), followed by carbamazepine (~40%) and ibuprofen (<~30%). In addition, the removal efficiency of the targeted pharmaceuticals in the constructed wetland was estimated by comparing the concentrations of the pharmaceuticals at sampling points with flowing water. The results showed that the removal efficiency of atenolol and carbamazepine was almost 50%, whereas that of ibuprofen was only ~10%. A comparison of the results of lab-scale and field experiments showed that electrostatic interaction is one of the major pharmaceutical removal mechanisms in a constructed wetland. Copyright © 2018 Elsevier B.V. All rights reserved.

Settling Efficiency of Urban Particulate Matter Transported by Stormwater Runoff.

PubMed

Carbone, Marco; Penna, Nadia; Piro, Patrizia

2015-09-01

The main purpose of control measures in urban areas is to retain particulate matter washed out by stormwater over impermeable surfaces. In stormwater control measures, particulate matter removal typically occurs via sedimentation. Settling column tests were performed to examine the settling efficiency of such units using monodisperse and heterodisperse particulate matter (for which the particle size distributions were measured and modelled by the cumulative gamma distribution). To investigate the dependence of settling efficiency from the particulate matter, a variant of the evolutionary polynomial regression (EPR), a Microsoft Excel function based on multi-objective EPR technique (EPR-MOGA), called EPR MOGA XL, was used as a data-mining strategy. The results from this study have shown that settling efficiency is a function of the initial total suspended solids (TSS) concentration and of the median diameter (d50 index), obtained from the particle size distributions (PSDs) of the samples.

Removal of organic matter and ammonia nitrogen from landfill leachate by ultrasound.

PubMed

Wang, Songlin; Wu, Xiaohui; Wang, Yansong; Li, Qifen; Tao, Meijun

2008-09-01

Experiments on the removal of organic matters and ammonia nitrogen from landfill leachate by ultrasound irradiation were carried out. The effects of COD reduction and ammonia removal of power input, initial concentration, initial pH and aeration were studied. It was found that the sonolysis of organic matters proceeds via reaction with ()OH radicals; a thermal reaction also occurs with a small contribution. The rise of COD at some intervals could be explained by the complexity of organic pollutant sonolysis in landfill leachate. Ultrasonic irradiation was shown to be an effective method for the removal of ammonia nitrogen from landfill leachate. After 180 min ultrasound irradiation, up to 96% ammonia nitrogen removal efficiency can be obtained. It was found that the mechanism of ammonia nitrogen removal by ultrasound irradiation is largely that the free ammonia molecules in leachate enter into the cavitation bubbles and transform into nitrogen molecules and hydrogen molecules via pyrolysis under instant high temperature and high pressure in the cavitation bubbles.

40 CFR 63.4362 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... applicable, during each test run. (b) Measure the volatile organic matter concentration as carbon at the... limit, only the outlet volatile organic matter concentration must be determined. The outlet volatile organic matter concentration is determined as the average of the three test runs. (1) Use Method 25 if the...

40 CFR 63.4362 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2012 CFR

2012-07-01

... applicable, during each test run. (b) Measure the volatile organic matter concentration as carbon at the... limit, only the outlet volatile organic matter concentration must be determined. The outlet volatile organic matter concentration is determined as the average of the three test runs. (1) Use Method 25 if the...

40 CFR 63.4362 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2013 CFR

2013-07-01

... applicable, during each test run. (b) Measure the volatile organic matter concentration as carbon at the... limit, only the outlet volatile organic matter concentration must be determined. The outlet volatile organic matter concentration is determined as the average of the three test runs. (1) Use Method 25 if the...

40 CFR 63.4362 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2014 CFR

2014-07-01

... applicable, during each test run. (b) Measure the volatile organic matter concentration as carbon at the... limit, only the outlet volatile organic matter concentration must be determined. The outlet volatile organic matter concentration is determined as the average of the three test runs. (1) Use Method 25 if the...

Advanced particulate matter control apparatus and methods

DOEpatents

Miller, Stanley J [Grand Forks, ND; Zhuang, Ye [Grand Forks, ND; Almlie, Jay C [East Grand Forks, MN

2012-01-10

Apparatus and methods for collection and removal of particulate matter, including fine particulate matter, from a gas stream, comprising a unique combination of high collection efficiency and ultralow pressure drop across the filter. The apparatus and method utilize simultaneous electrostatic precipitation and membrane filtration of a particular pore size, wherein electrostatic collection and filtration occur on the same surface.

Effects of electron beam irradiation and temperature on the treatment of swine wastewater using an ion exchange biological reactor.

PubMed

Lim, Seung Joo; Kim, Tak-Hyun; Lee, Sang-hun; Kim, Jun-young; Kim, Sun-kyoung

2013-06-01

Swine wastewater was treated using an ion exchange biological reactor (IEBR). Organic matter and nutrient in swine wastewater were pre-treated by electron beam irradiation. The optimal dose for solubilization of organic matter in swine wastewater ranged from 20 kGy to 75 kGy. The carbohydrates, proteins, and lipids were investigated as proteins and lipids mainly contained the solubilized organic matter. The solubilization of organic matter in swine wastewater was affected by the combination effects of temperature and dose. The maximum chemical oxygen demand (COD) and ammonia removal efficiencies were 74.4% and 76.7% at a dose of 0 kGy under room temperatures (23.0°C). The removal of ammonia was significantly affected by low temperature (15.3°C). On the other hand, the removal of phosphorus was not a function of electron beam irradiation or temperature because struvite is one of the main removal mechanisms under anoxic conditions. Published by Elsevier Ltd.

Automatic control and remote monitoring system for biological nutrient removal on small wastewater treatment plants in Korea.

PubMed

Lee, H; Min, Y M; Park, C H; Park, Y H

2004-01-01

Many small-size wastewater treatment plants in Korea's rural communities are designed to remove organic and suspended matter only, and they generally show a large fluctuation in the influent loading compared to municipal wastewater treatment plants (MWWTPs). They also have no professional engineers stationed for efficient operation against mechanical breakdown. For those reasons, the wastewater treatment plants have low efficiency in treatment of nitrogen and phosphorus as well as organic matter. In order to solve those problems, this study developed an automatic control system and RMS (remote monitoring system), which can keep efficiency stable despite any change in the small plants' loading rates and are capable of removing nutrient materials such as nitrogen or phosphorus. According to the results of the Experimental SBR system of the automatic control program, complete nitrification was made under oxic conditions and denitrification occurred as NO3-N concentration decreased by 0.5 mg/l in anoxic conditions and excellent nitrogen removal efficiency was seen generally. The Experimental SBR system created "phosphate release and uptake" effectively and displayed phosphate-removing efficiency up to more than 80% as the concentration of effluent was kept low by 0.4 mg/l. RMS developed in this study transmits a plant's data and operation states to clients in remote locations in real-time interval through the Internet. Therefore, although you are in a remote location, it allows you to see if a plant is properly operated or there is any breakdown.

Utilization of Natural Zeolite and Perlite as Landfill Liners for in Situ Leachate Treatment in Landfills

PubMed Central

Ozel, Ummukulsum; Akdemir, Andaç; Ergun, Osman Nuri

2012-01-01

The potential long term environmental impacts of a landfill on groundwater quality depend on its liner material properties. In case synthetic liner materials are damaged during the construction or operation, many of the original chemical and biological constituents are removed by filtration and the adsorptive action of natural liner materials such as natural zeolite, perlite and bentonite minerals. Before leachate treatment, reduction of these constituents is important not only to leachate percolation, but also treatment cost and efficiency. In this study, the pollutant removal efficiency from the leachate was investigated for natural natural zeolite, expanded perlite and bentonite. Experimental studies was performed in boxes made of glass and with 1:10 sloping. Leachate quantity was determined and pH, electrical conductivity (EC), nitrate (NO3-N), ammonium-nitrogen (NH4-N), phosphate (PO4), chemical oxygen demand (COD) and organic matter in leachate samples were measured and the measurement was compared with control process (System 4). The results showed that natural zeolite was effective in removing NO3, NH4, PO4, COD and organic matter with removal efficiencies of 91.20, 95.6, 95.5, 83.4 and 87.8%, respectively. Expanded perlite has high efficiency removing of NO3, PO4 and COD 83.2, 91.0 and 62.5%, respectively, but it was unsuccessful in reducing NH4 (1.5%). PMID:22754458

Utilization of natural zeolite and perlite as landfill liners for in situ leachate treatment in landfills.

PubMed

Ozel, Ummukulsum; Akdemir, Andaç; Ergun, Osman Nuri

2012-05-01

The potential long term environmental impacts of a landfill on groundwater quality depend on its liner material properties. In case synthetic liner materials are damaged during the construction or operation, many of the original chemical and biological constituents are removed by filtration and the adsorptive action of natural liner materials such as natural zeolite, perlite and bentonite minerals. Before leachate treatment, reduction of these constituents is important not only to leachate percolation, but also treatment cost and efficiency. In this study, the pollutant removal efficiency from the leachate was investigated for natural natural zeolite, expanded perlite and bentonite. Experimental studies was performed in boxes made of glass and with 1:10 sloping. Leachate quantity was determined and pH, electrical conductivity (EC), nitrate (NO(3)-N), ammonium-nitrogen (NH(4)-N), phosphate (PO(4)), chemical oxygen demand (COD) and organic matter in leachate samples were measured and the measurement was compared with control process (System 4). The results showed that natural zeolite was effective in removing NO(3), NH(4), PO(4), COD and organic matter with removal efficiencies of 91.20, 95.6, 95.5, 83.4 and 87.8%, respectively. Expanded perlite has high efficiency removing of NO(3), PO(4) and COD 83.2, 91.0 and 62.5%, respectively, but it was unsuccessful in reducing NH(4) (1.5%).

Comparison of biological activated carbon (BAC) and membrane bioreactor (MBR) for pollutants removal in drinking water treatment.

PubMed

Tian, J Y; Chen, Z L; Liang, H; Li, X; Wang, Z Z; Li, G B

2009-01-01

Biological activated carbon (BAC) and membrane bioreactor (MBR) were systematically compared for the drinking water treatment from slightly polluted raw water under the same hydraulic retention time (HRT) of 0.5 h. MBR exhibited excellent turbidity removal capacity due to the separation of the membrane; while only 60% of influent turbidity was intercepted by BAC. Perfect nitrification was achieved by MBR with the 89% reduction in ammonia; by contrast, BAC only eliminated a moderate amount of influent ammonia (by 54.5%). However, BAC was able to remove more dissolved organic matter (DOM, especially for organic molecules of 3,000 approximately 500 Daltons) and corresponding disinfection by-product formation potential (DBPFP) in raw water than MBR. Unfortunately, particulate organic matter (POM) was detected in the BAC effluent. On the other hand, BAC and MBR displayed essentially the same capacity for biodegradable organic matter (BOM) removal. Fractionation of DOM showed that the removal efficiencies of hydrophobic neutrals, hydrophobic acids, weakly hydrophobic acids and hydrophilic organic matter through BAC treatment were 11.7%, 8.8%, 13.9% and 4.8% higher than that through MBR; while MBR achieved 13.8% higher hydrophobic bases removal as compared with BAC.

Atrazine removal from water by polycation-clay composites: effect of dissolved organic matter and comparison to activated carbon.

PubMed

Zadaka, Dikla; Nir, Shlomo; Radian, Adi; Mishael, Yael G

2009-02-01

Atrazine removal from water by two polycations pre-adsorbed on montmorillonite was studied. Batch experiments demonstrated that the most suitable composite poly (4-vinylpyridine-co-styrene)-montmorillonite (PVP-co-S90%-mont.) removed 90-99% of atrazine (0.5-28 ppm) within 20-40 min at 0.367% w/w. Calculations employing Langmuir's equation could simulate and predict the kinetics and final extents of atrazine adsorption. Column filter experiments (columns 20x1.6 cm) which included 2g of the PVP-co-S90%-mont. composite mixed with excess sand removed 93-96% of atrazine (800 ppb) for the first 800 pore volumes, whereas the same amount of granular activated carbon (GAC) removed 83-75%. In the presence of dissolved organic matter (DOM; 3.7 ppm) the efficiency of the GAC filter to remove atrazine decreased significantly (68-52% removal), whereas the corresponding efficiency of the PVP-co-S90%-mont. filter was only slightly influenced by DOM. At lower atrazine concentration (7 ppb) the PVP-co-S90%-mont. filter reduced even after 3000 pore volumes the emerging atrazine concentration below 3 ppb (USEPA standard). In the case of the GAC filter the emerging atrazine concentration was between 2.4 and 5.3 microg/L even for the first 100 pore volumes. Thus, the PVP-co-S90%-mont. composite is a new efficient material for the removal of atrazine from water.

Removal of microcystin-LR from drinking water using a bamboo-based charcoal adsorbent modified with chitosan.

PubMed

Zhang, Hangjun; Zhu, Guoying; Jia, Xiuying; Ding, Ying; Zhang, Mi; Gao, Qing; Hu, Ciming; Xu, Shuying

2011-01-01

A new kind of low-cost syntactic adsorbent from bamboo charcoal and chitosan was developed for the removal of microcystin-LR from drinking water. Removal efficiency was higher for the syntactic adsorbent when the amount of bamboo charcoal was increased. The optimum dose ratio of bamboo charcoal to chitosan was 6:4, and the optimum amount was 15 mg/L; equilibrium time was 6 hr. The adsorption isotherm was non-linear and could be simulated by the Freundlich model (R2 = 0.9337). Adsorption efficiency was strongly affected by pH and natural organic matter (NOM). Removal efficiency was 16% higher at pH 3 than at pH 9. Efficiency rate was reduced by 15% with 25 mg/L NOM (UV254 = 0.089 cm(-1)) in drinking water. This study demonstrated that the bamboo charcoal modified with chitosan can effectively remove microcystin-LR from drinking water.

Crumb rubber filtration: a potential technology for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2006-05-01

The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between removal efficiency and filter depth. Higher filtration rate resulted in lower removal efficiency and higher head loss. Compared with conventional granular media filters, crumb rubber filters required less backwash, and developed lower head loss. Consequently crumb rubber filters could be run for a longer time or allow a higher filtration rate. The results also indicate that the crumb rubber filtration alone did not achieve the target removal of invasive species. However, crumb rubber filtration could potentially be used as a primary treatment technology to enhance the efficiency of a secondary treatment process (e.g., disinfection).

Enhanced performance of crumb rubber filtration for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2009-03-01

Waste-tire-derived crumb rubber was utilized as filter media to develop an efficient filter for ballast water treatment. In this study, the effects of coagulation, pressure filtration and dual-media (gravity) filtration on the performance of the crumb rubber filtration were investigated. The removal efficiencies of turbidity, phytoplankton and zooplankton, and head loss development were monitored during the filtration process. The addition of a coagulant enhanced the removal efficiencies of all targeted matter, but resulted in substantial increase of head loss. Pressure filtration increased filtration rates to 220 m(3)h(-1)m(-2) for 8-h operation and improved the zooplankton removal. Dual-media (crumb rubber/sand) gravity filtration also improved the removal efficiencies of phytoplankton and zooplankton over mono-media gravity crumb rubber filtration. However, these filtration techniques alone did not meet the criteria for removing indigenous organisms from ballast water. A combination of filtration and disinfection is suggested for future studies.

An investigation of the treatment of particulate matter from gasoline engine exhaust using non-thermal plasma.

PubMed

Ye, Dan; Gao, Dengshan; Yu, Gang; Shen, Xianglin; Gu, Fan

2005-12-09

A plasma reactor with catalysts was used to treat exhaust gas from a gasoline engine in order to decrease particulate matter (PM) emissions. The effect of non-thermal plasma (NTP) of the dielectric discharges on the removal of PM from the exhaust gas was investigated experimentally. The removal efficiency of PM was based on the concentration difference in PM for particle diameters ranging from 0.3 to 5.0 microm as measured by a particle counter. Several factors affecting PM conversion, including the density of plasma energy, reaction temperature, flow rate of exhaust gas, were investigated in the experiment. The results indicate that PM removal efficiency ranged approximately from 25 to 57% and increased with increasing energy input in the reactor, reaction temperature and residence time of the exhaust gas in the reactor. Enhanced removal of the PM was achieved by filling the discharge gap of the reactor with Cu-ZSM-5 catalyst pellets. In addition, the removal of unburned hydrocarbons was studied. Finally, available approaches for PM conversion were analyzed involving the interactions between discharge and catalytic reactions.

[Study on the advanced pre-treatments of reclaimed water used for groundwater recharge].

PubMed

Gao, Yu-Tuan; Zhang, Xue; Zhao, Xuan; Zhao, Gang

2012-03-01

To prevent groundwater contamination, pretreatments of reclaimed water are needed before the groundwater recharge. In this study, five treatments, including ultrafiltration (UF), ozonation, magnetic ion exchange (MIEX), UF coupled with ozonation and MIEX coupled with ozonation, were evaluated for their purification efficiencies of the reclaimed water and their influences on the following soil aquifer treatments. For organic matters in the secondary effluents, identified as dissolved organic carbon (DOC) and specific ultraviolet absorbance (SUVA), 20% DOC and 10% SUVA are removed by MIEX treatment with dose of 5 mL x L(-1), while only 10% DOC and no SUVA are removed by UF, but neither of these two pretreatments enhance the purification of soil aquifer treatments. Differently, SUVA of the secondary effluents are removed by 60%-79% by ozonation alone or coupled with UF/MIEX, increasing the biodegradability of the reclaimed water. These pretreatments significantly enhance the removal of organic matters by the following soil aquifer with DOC in the final effluents reducing to 1-2 mg x L(-1). For nitrogen, MIEX can remove 25% NO3(-) -N, and ozonation can remove 72% NH4(+) -N. The soil aquifer treatment could efficiently remove NH4(+) -N to below 0.5 mg x L(-1), while no obvious removal is detected for NO3(-) -N. In conclusion, more attentions should be paid to the organic matters and NO3(-) -N during the pretreatments of reclaimed water. Among all the pretreatments tested here, ozonation coupled with MIEX is capable of increasing the biodegradability of the reclaimed water and removing NO3(-) -N, which is a good choice for the pretreatment of groundwater recharge.

Cation-induced coagulation of aquatic plant-derived dissolved organic matter: Investigation by EEM-PARAFAC and FT-IR spectroscopy.

PubMed

Liu, Shasha; Zhu, Yuanrong; Liu, Leizhen; He, Zhongqi; Giesy, John P; Bai, Yingchen; Sun, Fuhong; Wu, Fengchang

2018-03-01

Complexation and coagulation of plant-derived dissolved organic matter (DOM) by metal cations are important biogeochemical processes of organic matter in aquatic systems. Thus, coagulation and fractionation of DOM derived from aquatic plants by Ca(II), Al(III), and Fe(III) ions were investigated. Metal ion-induced removal of DOM was determined by analyzing dissolved organic carbon in supernatants after addition of these metal cations individually. After additions of metal ions, both dissolved and coagulated organic fractions were characterized by use of fluorescence excitation emission matrix-parallel factor (EEM-PARAFAC) analysis and Fourier transform infrared (FT-IR) spectroscopy. Addition of Ca(II), Fe(III) or Al(III) resulted in net removal of aquatic plant-derived DOM. Efficiencies of removal of DOM by Fe(III) or Al(III) were greater than that by Ca(II). However, capacities to remove plant-derived DOM by the three metals were less than which had been previously reported for humic materials. Molecular and structural features of plant-derived DOM fractions in associations with metal cations were characterized by changes in fluorescent components and infrared absorption peaks. Both aromatic and carboxylic-like organic matters could be removed by Ca(II), Al(III) or Fe(III) ions. Whereas organic matters containing amides were preferentially removed by Ca(II), and phenolic materials were selectively removed by Fe(III) or Al(III). These observations indicated that plant-derived DOM might have a long-lasting effect on water quality and organisms due to its poor coagulation with metal cations in aquatic ecosystems. Plant-derived DOM is of different character than natural organic matter and it is not advisable to attempt removal through addition of metal salts during treatment of sewage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced removal of natural organic matters by calcined Mg/Al layered double hydroxide nanocrystalline particles: Adsorption, reusability and mechanism studies

NASA Astrophysics Data System (ADS)

Fang, Liping; Hou, Jingwei; Xu, Cuihong; Wang, Yaru; Li, Ji; Xiao, Feng; Wang, Dongsheng

2018-06-01

Natural organic matters (NOMs) can generate disinfection by-products during water treatment process, threatening to human health. However, the removal of NOM is still unsatisfactory in water treatment. Hence, this work investigated the removal efficiency of humic and fulvic acids (HA and FA) by layered double hydroxide (LDH) and its calcined forms under different conditions. Our results show that calcination of LDH at 500 °C can effectively enhance the NOM removal with adsorption capacities of 98.8 mg/g for HA and 97.6 mg/g for FA at pH 9.5. The removal efficiency of HA and FA notably increases by decreasing pH. The presence of SO42- and CO32- significantly suppresses the removal of HA or FA by CLDHs. The release of Al from LDH and CLDH is negligible and safe to aquatic organisms at pH > 6.5. Moreover, CLDH shows a good reusability for NOM removal in water treatment. The removal of HA and FA by CLDH is governed through electrostatic interactions and intercalation into the interlayers of LDH was not observed. Fluorescence and molecular weight analyses show that the microbial by-products with mid-molecular weight are more difficult to be removed than HA and FA. This study provides a new insight into the NOM removal using LDH and CLDH.

Effect of water depth on the removal of organic matter in horizontal subsurface flow constructed wetlands.

PubMed

Aguirre, Paula; Ojeda, Esther; García, Joan; Barragán, Jesús; Mujeriego, Rafael

2005-01-01

The objective of this article is to evaluate the effect of water depth on organic matter removal efficiency in horizontal subsurface flow constructed wetlands (SSFs). Experiments were carried out in a pilot plant comprising eight parallel SSF of almost equal surface area (54-56 m2 each) and treating urban wastewater. Each SSF differs from the others in the aspect ratio or the size of the granular medium or the water depth. During a period of two years, the shallow SSFs (0.27 m water depth) removed more chemical oxygen demand (COD) (72-81%), biochemical oxygen demand (BOD)5 (72-85%), ammonia (35-56%), and dissolved reactive phosphorus (DRP) (8-23%) than deep SSFs (0.5 m water depth) (59-64% for COD; 51-57% for BOD5; 18-29% for ammonia; and 0-7% for DRP). Experiments carried out during the summer indicated that sulphate reduction accounted for a clearly higher organic matter removal in the deep SSFs than in the shallow ones. Denitrification seemed to be a significant mechanism for organic matter removal to occur in shallow SSFs. The results suggest that the relative contribution of different metabolic pathways varies with depth.

Removal of organic matter from a variety of water matrices by UV photolysis and UV/H2O2 method.

PubMed

Vilhunen, Sari; Vilve, Miia; Vepsäläinen, Mikko; Sillanpää, Mika

2010-07-15

A re-circulated flow-through photoreactor was used to evaluate the ultraviolet (UV) photolysis and UV/H(2)O(2) oxidation process in the purification of three different water matrices. Chemically coagulated and electrocoagulated surface water, groundwater contaminated with creosote wood preservative and 1,2-dichloroethane (DCE) containing washing water from the plant manufacturing tailor-made ion-exchange resins were used as sample waters. The organic constituents of creosote consist mainly of harmful polycyclic aromatic hydrocarbons (PAH) whereas 1,2-DCE is a toxic volatile organic compound (VOC). Besides analyzing the specific target compounds, total organic carbon (TOC) analysis and measurement of change in UV absorbance at 254 nm (UV(254)) were performed. Initial TOC, UV(254) and pH varied significantly among treated waters. Initial H(2)O(2) concentrations 0-200 mg/l were used. The UV/H(2)O(2) treatment was efficient in removing the hazardous target pollutants (PAHs and 1,2-DCE) and natural organic matter (NOM). In addition, high removal efficiency for TOC was achieved for coagulated waters and groundwater. Also, the efficiency of direct photolysis in UV(254) removal was significant except in the treatment of 1,2-DCE containing washing water. Overall, UV(254) and TOC removal rates were high, except in case of washing water, and the target pollutants were efficiently decomposed with the UV/H(2)O(2) method. 2010 Elsevier B.V. All rights reserved.

Characteristics of BPA removal from water by PACl-Al13 in coagulation process.

PubMed

Xiaoying, Ma; Guangming, Zeng; Chang, Zhang; Zisong, Wang; Jian, Yu; Jianbing, Li; Guohe, Huang; Hongliang, Liu

2009-09-15

This paper discussed the coagulation characteristics of BPA with polyaluminum chloride (PACl-Al(13)) as coagulant, examined the impact of coagulation pH, PACl-Al(13) dosage, TOC (total organic carbon) and turbidity on BPA removal, and analyzed the possible dominant mechanisms in water coagulation process. Formation and performance of flocs during coagulation processes were monitored using photometric dispersion analyzer (PDA). When the concentration of humic acid matters and turbidity was low in the solution, the experimental results showed that the removal of BPA experienced increase and subsequently decrease with the PACl-Al(13) dosage increasing. The optimal PACl-Al(13) dosage was found at BPA/PACl-Al(13)=1:2.6(M/M) under our experiment conditions. Results show that the maximum BPA removal efficiency occurred at pH 9.0 due to the adsorption by Al(13) aggregates onto BPA rather than charge neutralization mechanism by polynuclear aluminous salts in the solution. The humic acid matters and kaolin in the solution have significant effect on BPA removal with PACl-Al(13) in the coagulation. The BPA removal will be weakened at high humic matters. The removal rate of BPA increased and subsequently decreased with the turbidity increasing.

Performance and microbial community of anammox in presence of micro-molecule carbon source.

PubMed

He, Shilong; Yang, Wan; Qin, Meng; Mao, Zhen; Niu, Qigui; Han, Ming

2018-08-01

Because ammonium (NH 4 + -N) coexists with organic matter in some wastewaters, the possible adverse influences of organic matter become a major concern in the applications of anaerobic ammonium oxidation (anammox). In this study, the effects of acetate, as a representative of micro-molecule organic matter, on anammox were investigated. Efficient nitrogen removal was realized because denitrifying bacteria and anammox bacteria (AnAOB) had a better synergistic effect under the condition of chemical oxygen demand (COD) concentrations lower than 251 ± 7 mg L -1 . Furthermore, the nitrogen removal efficiency (NRE) decreased to 82.02 ± 3.14% when COD was increased to 730 ± 9 mg L -1 , and effluent free ammonia (FA) reached 21.93 ± 4.71 mg L -1 might be one of factors leading to inhibition. However, the nitrogen-removal contribution rate of anammox remained steady at 61.97 ± 2.84% at COD of 730 ± 9 mg L -1 , which indicated that anammox was still dominant in the system. AnAOB, such as Ca. Kuenenia and Ca. Jettenia, and denitrifying bacteria, such as Denitratisoma and Thauera, were found to coexist in the reactor. Interestingly, Ca. Kuenenia presented in the trend of first decreased then increased with the increasing of organic matter concentration, which might be one of reasons that anammox played an important role in nitrogen removal at high COD concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simultaneous removals of NOx, HC and PM from diesel exhaust emissions by dielectric barrier discharges.

PubMed

Song, Chong-Lin; Bin, Feng; Tao, Ze-Min; Li, Fang-Cheng; Huang, Qi-Fei

2009-07-15

The main target of this work is to characterize the abatements of particulate matter (PM), hydrocarbons (HC) and nitrogen oxides (NO(x)) from an actual diesel exhaust using dielectric barrier discharge technology (DBD). The effects of several parameters, such as peak voltage, frequency and engine load, on the contaminant removals have been investigated intensively. The present study shows that for a given frequency, the removals of PM and HC are enhanced with the increase of peak voltage and level off at higher voltage, while in the range of higher voltages a decline of NO(x) removal efficiency is observed. For a given voltage, the maximums of specific energy density (SED) and removal efficiency are attained at resonance point. The increase of peak voltage will result in a significant decrease of energy utilization efficiency of DBD at most engine loads. Alkanes in soluble organic fraction (SOF) are more readily subjected to removals than polycyclic aromatic hydrocarbons (PAHs).

Fe(II)-regulated moderate pre-oxidation of Microcystis aeruginosa and formation of size-controlled algae flocs for efficient flotation of algae cell and organic matter.

PubMed

Qi, Jing; Lan, Huachun; Liu, Ruiping; Liu, Huijuan; Qu, Jiuhui

2018-06-15

The coagulation/flocculation/flotation (C/F/F) process is becoming a popular method for algae-laden water treatment. However, the efficiency of flotation is highly dependent on the ability of the preceding coagulation/flocculation process to form flocculated algae flocs. This study aims to improve the Microcystis aeruginosa flotation efficiency from algae cell and organic matter aspects by applying Fe(II)-regulated pretreatment enhanced Al coagulation process. The ability of the C/F/F process to remove cyanobacterial cells can be enhanced from 8% to 99% at a Fe(II) dose of 30 μM. The Al dose needed can be reduced by more than half while achieving successful flotation. The introduced Fe(II) after KMnO 4 can not only realize moderate pre-oxidation of cyanobacterial cells, but also form in-situ Fe(III). The DOC value can also be decreased significantly due to the formation of in-situ Fe(III), which is more efficient in dissolved organic matter (DOM) removal compared with pre-formed Fe(III). In addition, the gradually hydrolyzed in-situ Fe(III) can facilitate the hydrolysis of Al as a dual-coagulant and promote the clustering and cross-linking of Al hydrolyzates, which can enhance the formation of size-controlled algae flocs. Finally, the size-controlled algae flocs can be effectively floated by the bubbles released in the flotation process due to the efficient collision and attachment between flocs and bubbles. Therefore, the efficient flotation of algae cell and organic matter can be realized by the Fe(II) regulated moderate pre-oxidation of M. aeruginosa and formation of size-controlled algae flocs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Natural organic matters removal efficiency by coagulation

NASA Astrophysics Data System (ADS)

Sapingi, Mohd Sharizal Mohd; Pishal, Munirah; Murshed, Mohamad Fared

2017-10-01

The presence of Natural Organic Matter (NOM) in surface water results in unwanted characteristics in terms of color, odor, and taste. NOM content reaction with free chlorine in treated water lowers the water quality further. Chlorine is added for disinfection and produces undesirable disinfection by-products (DPBs). DBPs in drinking water are carcinogenic to consumers and may promote cancerous cell development in the human body. This study was performed to compare the coagulant efficiency of aluminum sulfate (Alum) and ferric chloride (FeCl3) on NOM removal (as in UV254 absorbance) and turbidity removal under three pH conditions (pH 6, pH 7, and sample actual pH). The three sampling points for these studies were Jalan Baru River, Kerian River, and Redac Pond. Additional sampling points, such as Lubuk Buntar and a tubewell located in the Civil Engineering School, were included to observe differences in characteristics. DOC, UV absorbance, and full wavelength were tested, after which samples treated with alum were also tested to further analyze the NOM content. Based on UV254 absorbance and DOC data, specific UV value was calculated to obtain vital synopsis of the characteristics of NOM content, as well as coagulation efficiency.

Hierarchical Metal-Organic Framework-Assembled Membrane Filter for Efficient Removal of Particulate Matter.

PubMed

Koo, Won-Tae; Jang, Ji-Soo; Qiao, Shaopeng; Hwang, Wontae; Jha, Gaurav; Penner, Reginald M; Kim, Il-Doo

2018-06-13

Here, we propose heterogeneous nucleation-assisted hierarchical growth of metal-organic frameworks (MOFs) for efficient particulate matter (PM) removal. The assembly of two-dimensional (2D) Zn-based zeolite imidazole frameworks (2D-ZIF-L) in deionized water over a period of time produced hierarchical ZIF-L (H-ZIF-L) on hydrophilic substrates. During the assembly, the second nucleation and growth of ZIF-L occurred on the surface of the first ZIF-L, leading to the formation of flowerlike H-ZIF-L on the substrate. The flowerlike H-ZIF-L was easily synthesized on various substrates, namely, glass, polyurethane three-dimensional foam, nylon microfibers, and nonwoven fabrics. We demonstrated H-ZIF-L-assembled polypropylene microfibers as a washable membrane filter with highly efficient PM removal property (92.5 ± 0.8% for PM 2.5 and 99.5 ± 0.2% for PM 10 ), low pressure drop (10.5 Pa at 25 L min -1 ), long-term stability, and superior recyclability. These outstanding particle filtering properties are mainly attributed to the unique structure of the 2D-shaped H-ZIF-L, which is tightly anchored on individual fibers comprising the membrane.

Calcium and organic matter removal by carbonation process with waste incineration flue gas towards improvement of leachate biotreatment performance.

PubMed

Zhang, Cheng; Zhu, Xuedong; Wu, Liang; Li, Qingtao; Liu, Jianyong; Qian, Guangren

2017-09-01

Municipal solid wastes incineration (MSWI) flue gas was employed as the carbon source for in-situ calcium removal from MSWI leachate. Calcium removal efficiency was 95-97% with pH of 10.0-11.0 over 100min of flue gas aeration, with both bound Ca and free Ca being removed effectively. The fluorescence intensity of tryptophan, protein-like and humic acid-like compounds increased after carbonation process. The decrease of bound Ca with the increase of precipitate indicated that calcium was mainly converted to calcium carbonate precipitate. It suggested that the interaction between dissolved organic matter and Ca 2+ was weakened. Moreover, 10-16% of chemical oxygen demand removal and the decrease of ultraviolet absorption at 254nm indicated that some organics, especially aromatic compound decreased via adsorption onto the surface of calcium carbonate. The results indicate that introduce of waste incineration flue gas could be a feasible way for calcium removal from leachate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impacts of continuously regenerating trap and particle oxidation catalyst on the NO2 and particulate matter emissions emitted from diesel engine.

PubMed

Liu, Zhihua; Ge, Yunshan; Tan, Jianwei; He, Chao; Shah, Asad Naeem; Ding, Yan; Yu, Linxiao; Zhao, Wei

2012-01-01

Two continuously regenerating diesel particulate filter (CRDPF) with different configurations and one particles oxidation catalyst (POC) were employed to perform experiments in a controlled laboratory setting to evaluate their effects on NO2, smoke and particle number emissions. The results showed that the application of the after-treatments increased the emission ratios of NO2/NOx significantly. The results of smoke emissions and particle number (PN) emissions indicated that both CRDPFs had sufficient capacity to remove more than 90% of total particulate matter (PM) and more than 97% of solid particles. However, the POC was able to remove the organic components of total PM, and only partially to remove the carbonaceous particles with size less than 30 nm. The negligible effects of POC on larger particles were observed due to its honeycomb structure leads to an inadequate residence time to oxidize the solid particles or trap them. The particles removal efficiencies of CRDPFs had high degree of correlations with the emission ratio of NO2/NOx. The PN emission results from two CRDPFs indicated that more NO2 generating in diesel oxidation catalyst section could obtain the higher removal efficiency of solid particles. However this also increased the risk of NO2 exposure in atmosphere.

Defluoridation potential of jute fibers grafted with fatty acyl chain

NASA Astrophysics Data System (ADS)

Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam

2015-11-01

Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electro dialysis or reverse osmosis. These processes are often effective over narrow pH ranges, release ions considered hazardous to human health or produce large volumes of toxic sludge that are difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids, an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C-F bonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride.

Removal of pharmaceuticals and organic matter from municipal wastewater using two-stage anaerobic fluidized membrane bioreactor.

PubMed

Dutta, Kasturi; Lee, Ming-Yi; Lai, Webber Wei-Po; Lee, Chien Hsien; Lin, Angela Yu-Chen; Lin, Cheng-Fang; Lin, Jih-Gaw

2014-08-01

The aim of present study was to treat municipal wastewater in two-stage anaerobic fluidized membrane bioreactor (AFMBR) (anaerobic fluidized bed reactor (AFBR) followed by AFMBR) using granular activated carbon (GAC) as carrier medium in both stages. Approximately 95% COD removal efficiency could be obtained when the two-stage AFMBR was operated at total HRT of 5h (2h for AFBR and 3h for AFMBR) and influent COD concentration of 250mg/L. About 67% COD and 99% TSS removal efficiency could be achieved by the system treating the effluent from primary clarifier of municipal wastewater treatment plant, at HRT of 1.28h and OLR of 5.65kg COD/m(3)d. The system could also effectively remove twenty detected pharmaceuticals in raw wastewaters with removal efficiency in the range of 86-100% except for diclofenac (78%). No other membrane fouling control was required except scouring effect of GAC for flux of 16LMH. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nitrogen removal performance of anaerobic ammonia oxidation (ANAMMOX) in presence of organic matter.

PubMed

Zhu, Weiqiang; Zhang, Peiyu; Yu, Deshuang; Dong, Huiyu; Li, Jin

2017-06-01

A sequencing batch reactor (SBR) was used to test the nitrogen removal performance of anaerobic ammonium oxidation (ANAMMOX) in presence of organic matter. Mesophilic operation (30 ± 0.5 °C) was performed with influent pH 7.5. The results showed, independent of organic matter species, ANAMMOX reaction was promoted when COD was lower than 80 mg/L. However, specific ANAMMOX activity decreased with increasing organic matter content. Ammonium removal efficiency decreased to 80% when COD of sodium succinate, sodium potassium tartrate, peptone and lactose were 192.5, 210, 225 and 325 mg/L, respectively. The stoichiometry ratio resulting from different OM differed largely and R 1 could be as an indicator for OM inhibition. When COD concentration was 240 mg/L, the loss of SAA resulting from lactose, peptone, sodium potassium tartrate and sodium succinate were 28, 36, 50 and 55%, respectively. Sodium succinate had the highest inhibitory effect on SAA. When ANAMMOX process was used to treat wastewater containing OM, the modified Logistic model could be employed to predict the NRE max .

Gypsum and organic matter distribution in a mixed construction and demolition waste sorting process and their possible removal from outputs.

PubMed

Montero, A; Tojo, Y; Matsuo, T; Matsuto, T; Yamada, M; Asakura, H; Ono, Y

2010-03-15

With insufficient source separation, construction and demolition (C&D) waste becomes a mixed material that is difficult to recycle. Treatment of mixed C&D waste generates residue that contains gypsum and organic matter and poses a risk of H(2)S formation in landfills. Therefore, removing gypsum and organic matter from the residue is vital. This study investigated the distribution of gypsum and organic matter in a sorting process. Heavy liquid separation was used to determine the density ranges in which gypsum and organic matter were most concentrated. The fine residue that was separated before shredding accounted for 27.9% of the waste mass and contained the greatest quantity of gypsum; therefore, most of the gypsum (52.4%) was distributed in this fraction. When this fine fraction was subjected to heavy liquid separation, 93% of the gypsum was concentrated in the density range of 1.59-2.28, which contained 24% of the total waste mass. Therefore, removing this density range after segregating fine particles should reduce the amount of gypsum sent to landfills. Organic matter tends to float as density increases; nevertheless, separation at 1.0 density could be more efficient. (c) 2009 Elsevier B.V. All rights reserved.

Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, ZhiPing, E-mail: liulqs@163.com; Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020; Wu, WenHui

Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD{sub 5}) and ammonia nitrogen (NH{sub 3}−N) by themore » combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.« less

Effect of alkalinity on nitrite accumulation in treatment of coal chemical industry wastewater using moving bed biofilm reactor.

PubMed

Hou, Baolin; Han, Hongjun; Jia, Shengyong; Zhuang, Haifeng; Zhao, Qian; Xu, Peng

2014-05-01

Nitrogen removal via nitrite (the nitrite pathway) is more suitable for carbon-limited industrial wastewater. Partial nitrification to nitrite is the primary step to achieve nitrogen removal via nitrite. The effect of alkalinity on nitrite accumulation in a continuous process was investigated by progressively increasing the alkalinity dosage ratio (amount of alkalinity to ammonia ratio, mol/mol). There is a close relationship among alkalinity, pH and the state of matter present in aqueous solution. When alkalinity was insufficient (compared to the theoretical alkalinity amount), ammonia removal efficiency increased first and then decreased at each alkalinity dosage ratio, with an abrupt removal efficiency peak. Generally, ammonia removal efficiency rose with increasing alkalinity dosage ratio. Ammonia removal efficiency reached to 88% from 23% when alkalinity addition was sufficient. Nitrite accumulation could be achieved by inhibiting nitrite oxidizing bacteria (NOB) by free ammonia (FA) in the early period and free nitrous acid in the later period of nitrification when alkalinity was not adequate. Only FA worked to inhibit the activity of NOB when alkalinity addition was sufficient. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Experimental investigation and modeling of dissolved organic carbon removal by coagulation from seawater.

PubMed

Jeong, Sanghyun; Sathasivan, Arumugam; Kastl, George; Shim, Wang Geun; Vigneswaran, Saravanamuthu

2014-01-01

Coagulation removes colloidal matters and dissolved organic carbon (DOC) which can cause irreversible membrane fouling. However, how DOC is removed by coagulant is not well-known. Jar test was used to study the removal of hydrophobic and hydrophilic DOC fractions at various doses (0.5-8.0 mg-Fe(+3) L(-1)) of ferric chloride (FeCl3) and pH (5.0-9.0). Natural organic matter (NOM) in seawater and treated seawater were fractionated by liquid chromatography-organic carbon detector (LC-OCD). Compared to surface water, the removal of DOC in seawater by coagulation was remarkably different. Majority of DOC could be easily removed with very low coagulant dose (<5.0 mg-Fe(+3) L(-1)) and the removal efficiency did not vary with pH, but the DOC composition in treated water had significantly changed. Hydrophobic fraction (HB) was better removed at high pH while hydrophilic fraction (HF) was better removed at low pH. A modified model of Kastl et al. (2004) which assumed that the removal occurred by adsorption of un-dissociated compounds onto ferric hydroxide was formulated and successfully validated against the jar test data. Copyright © 2013 Elsevier Ltd. All rights reserved.

Recycling acetic acid from polarizing film of waste liquid crystal display panels by sub/supercritical water treatments.

PubMed

Wang, Ruixue; Chen, Ya; Xu, Zhenming

2015-05-19

Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate) and organic materials (polarizing film and liquid crystal). The organic materials should be removed first since containing polarizing film and liquid crystal is to the disadvantage of the indium recycling process. In the present study, an efficient and environmentally friendly process to obtain acetic acid from waste LCD panels by sub/supercritical water treatments is investigated. Furthermore, a well-founded reaction mechanism is proposed. Several highlights of this study are summarized as follows: (i) 99.77% of organic matters are removed, which means the present technology is quite efficient to recycle the organic matters; (ii) a yield of 78.23% acetic acid, a quite important fossil energy based chemical product is obtained, which can reduce the consumption of fossil energy for producing acetic acid; (iii) supercritical water acts as an ideal solvent, a requisite reactant as well as an efficient acid-base catalyst, and this is quite significant in accordance with the "Principles of Green Chemistry". In a word, the organic matters of waste LCD panels are recycled without environmental pollution. Meanwhile, this study provides new opportunities for alternating fossil-based chemical products for sustainable development, converting "waste" into "fossil-based chemicals".

Test and Evaluation of a Pilot System for Ion Exchange Treatment of Cadmium Cyanide Wastes

DTIC Science & Technology

1993-09-01

rate, metal concentration and solution chemistry , and temperature. These factors affect the diffusion rate of metal ions from the bulk solution to the...Changes in Cd2+ or CN- resin capacity and removal efficiency after a number of regeneration cycles; • Discharge leakage levels of Cd2+ and CN- after...a filter to remove any suspended solids, an activated-carbon column to remove any organic matter (this step was not utilized since organic levels

Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

PubMed

Ajmani, Gaurav S; Cho, Hyun-Hee; Abbott Chalew, Talia E; Schwab, Kellogg J; Jacangelo, Joseph G; Huang, Haiou

2014-08-01

Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p < 0.01), but there was also a significant linear relationship between static and dynamic removal (p < 0.05). Accounting for contact time of CNTs with NOM during filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of aeration and effluent recycling on domestic wastewater treatment in a pilot-plant system of duckweed ponds.

PubMed

Ben-shalom, Miriam; Shandalov, Semion; Brenner, Asher; Oron, Gideon

2014-01-01

Three pilot-scale duckweed pond (DP) wastewater treatment systems were designed and operated to examine the effect of aeration and effluent recycling on treatment efficiency. Each system consisted of two DPs in series fed by pre-settled domestic sewage. The first system (duckweed+ conventional treatment) was 'natural' and included only duckweed plants. The second system (duckweed aeration) included aeration in the second pond. The third system (duckweed+ aeration+ circulation) included aeration in the second pond and effluent recycling from the second to the first pond. All three systems demonstrated similarly efficient removal of organic matter and nutrients. Supplemental aeration had no effect on either dissolved oxygen levels or on pollutant removal efficiencies. Although recycling had almost no influence on nutrient removal efficiencies, it had a positive impact on chemical oxygen demand and total suspended solids removals due to equalization of load and pH, which suppressed algae growth. Recycling also improved the appearance and growth rate of the duckweed plants, especially during heavy wastewater loads.

Organic matters removal from landfill leachate by immobilized Phanerochaete chrysosporium loaded with graphitic carbon nitride under visible light irradiation.

PubMed

Hu, Liang; Liu, Yutang; Zeng, Guangming; Chen, Guiqiu; Wan, Jia; Zeng, Yunxiong; Wang, Longlu; Wu, Haipeng; Xu, Piao; Zhang, Chen; Cheng, Min; Hu, Tianjue

2017-10-01

This study investigated the technical applicability of a combination of Phanerochaete chrysosporium (P. chrysosporium) with photocatalyst graphitic carbon nitride (g-C 3 N 4 ) for organic matters removal from landfill leachate under visible light irradiation. Photocatalyst g-C 3 N 4 was well immobilized on the hyphae surface of P. chrysosporium by calcium alginate. The typical absorption edge in visible light region for g-C 3 N 4 was at about 460 nm, and the optical absorption bandgap of g-C 3 N 4 was estimated to be 2.70 eV, demonstrating the great photoresponsive ability of g-C 3 N 4 . An optimized g-C 3 N 4 content of 0.10 g in immobilized P. chrysosporium and an optimized immobilized P. chrysosporium dosage of 1.0 g were suitable for organic matters removal. The removal efficiency of total organic carbon (TOC) reached 74.99% in 72 h with the initial TOC concentration of 100 mg L -1 . In addition, the gas chromatography coupled with mass spectrometry (GC-MS) measurements showed that immobilized P. chrysosporium presented an outstanding removal performance for almost all organic compounds in landfill leachate, especially for the volatile fatty acids and long-chain hydrocarbons. The overall results indicate that the combination P. chrysosporium with photocatalyst g-C 3 N 4 for organic matters removal from landfill leachate may provide a more comprehensive potential for the landfill leachate treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal and transformation of effluent organic matter (EfOM) in biotreated textile wastewater by GAC/O3 pre-oxidation and enhanced coagulation.

PubMed

Qian, Feiyue; Sun, Xianbo; Liu, Yongdi; Xu, Hongyong

2013-01-01

GAC/O3 (ozonation in the presence of granular activated carbon) combined with enhanced coagulation was employed to process biotreated textile wastewater for possible reuse. The doses of ozone, GAC and coagulant were the variables studied for optimization. The effects of different treatment processes on effluent organic matter (EfOM) characteristics, including biodegradability, hydrophobic and hydrophilic nature, and apparent molecular weight (AMW) distribution were also investigated. Compared with ozonation, GAC/O3 not only presented a higher pre-oxidation efficiency, but also improved the treatability of hydrophobic and high molecular weight compounds by enhanced coagulation. After treatment by GAC/O3 pre-oxidation (0.6 mg O3 x mg(-1) COD and 20 g x L(-1) GAC) and enhanced coagulation (25 mg x L(-1) Al3+ at pH 5.5), the removal efficiencies of chemical oxygen demand (COD), dissolved organic carbon (DOC) and colour were higher than those for coagulation alone by 17.3%, 12.0% and 25.6%, respectively. Residual organic matter consisted mainly of hydrophobic acids and hydrophilic compounds of AMW < 1 kDa, which were colourless and of limited biological availability. The combination of GAC/O3 and enhanced coagulation was proved to be a simple and effective treatment strategy for removing EfOM from biotreated textile wastewater.

Electricity generation through a photo sediment microbial fuel cell using algae at the cathode.

PubMed

Neethu, B; Ghangrekar, M M

2017-12-01

Sediment microbial fuel cells (SMFCs) are bio-electrochemical devices generating electricity from redox gradients occurring across the sediment-water interface. Sediment microbial carbon-capture cell (SMCC), a modified SMFC, uses algae grown in the overlying water of sediment and is considered as a promising system for power generation along with algal cultivation. In this study, the performance of SMCC and SMFC was evaluated in terms of power generation, dissolved oxygen variations, sediment organic matter removal and algal growth. SMCC gave a maximum power density of 22.19 mW/m 2 , which was 3.65 times higher than the SMFC operated under similar conditions. Sediment organic matter removal efficiencies of 77.6 ± 2.1% and 61.0 ± 1.3% were obtained in SMCC and SMFC, respectively. With presence of algae at the cathode, a maximum chemical oxygen demand and total nitrogen removal efficiencies of 63.3 ± 2.3% (8th day) and 81.6 ± 1.2% (10th day), respectively, were observed. The system appears to be favorable from a resources utilization perspective as it does not depend on external aeration or membranes and utilizes algae and organic matter present in sediment for power generation. Thus, SMCC has proven its applicability for installation in an existing oxidation pond for sediment remediation, algae growth, carbon conversion and power generation, simultaneously.

Efficient Filtration of Effluent Organic Matter by Polycation-Clay Composite Sorbents: Effect of Polycation Configuration on Pharmaceutical Removal.

PubMed

Shabtai, Itamar A; Mishael, Yael G

2016-08-02

Hybrid polycation-clay composites, based on methylated poly vinylpyridinium, were optimized as sorbents for secondary effluent organic matter (EfOM) including emerging micropollutants. Composite structure was tuned by solution ionic strength and characterized by zeta potential, FTIR, X-ray diffraction, and thermal gravimetric analyses. An increase in ionic strength induced a transition from a train to a loops and tails configuration, accompanied by greater polycation adsorption. Composite charge reversal (zeta potential -18 to 45 mV) increased the adsorption of EfOM and humic acid (HA), moderately and sharply, respectively, suggesting electrostatic and also nonspecific interactions with EfOM. Filtration of EfOM by columns of positively charged composites was superior to that of granular activated carbon (GAC). The overall removal of EfOM was most efficient by the composite with a train configuration. Whereas a composite with a loops and tails configuration was beneficial for the removal of the anionic micropollutants diclofenac, gemfibrozil and ibuprofen from EfOM. These new findings suggest that the loops and tails may offer unique binding sites for small micropollutants which are overseen by the bulk EfOM. Furthermore, they may explain our previous observations that in the presence of dissolved organic matter, micropollutant filtration by GAC columns was reduced, while their filtration by composite columns remained high.

Municipal waste liquor treatment via bioelectrochemical and fermentation (H2 + CH4) processes: Assessment of various technological sequences.

PubMed

Rózsenberszki, Tamás; Koók, László; Bakonyi, Péter; Nemestóthy, Nándor; Logroño, Washington; Pérez, Mario; Urquizo, Gladys; Recalde, Celso; Kurdi, Róbert; Sarkady, Attila

2017-03-01

In this paper, the anaerobic treatment of a high organic-strength wastewater-type feedstock, referred as the liquid fraction of pressed municipal solid waste (LPW) was studied for energy recovery and organic matter removal. The processes investigated were (i) dark fermentation to produce biohydrogen, (ii) anaerobic digestion for biogas formation and (iii) microbial fuel cells for electrical energy generation. To find a feasible alternative for LPW treatment (meeting the two-fold aims given above), various one- as well as multi-stage processes were tested. The applications were evaluated based on their (i) COD removal efficiencies and (ii) specific energy gain. As a result, considering the former aspect, the single-stage processes could be ranked as: microbial fuel cell (92.4%)> anaerobic digestion (50.2%)> hydrogen fermentation (8.8%). From the latter standpoint, an order of hydrogen fermentation (2277 J g -1  COD removed  d -1 )> anaerobic digestion (205 J g -1  COD removed  d -1 )> microbial fuel cell (0.43 J g -1  COD removed  d -1 ) was attained. The assessment showed that combined, multi-step treatment was necessary to simultaneously achieve efficient organic matter removal and energy recovery from LPW. Therefore, a three-stage system (hydrogen fermentation-biomethanation-bioelectrochemical cell in sequence) was suggested. The different approaches were characterized via the estimation of COD balance, as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reductions of dissolved organic matter and disinfection by-product precursors in full-scale wastewater treatment plants in winter.

PubMed

Xue, Shuang; Jin, Wujisiguleng; Zhang, Zhaohong; Liu, Hong

2017-07-01

The reductions of dissolved organic matter (DOM) and disinfection byproduct precursors in four full-scale wastewater treatment plants (WWTPs) (Liaoning Province, China) where different biological treatment processes were employed in winter were investigated. The total removal efficiencies of dissolved organic carbon (DOC), ultraviolet light at 254 nm (UV-254), trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) were in the range of 70.3-76.0%, 49.6-57.3%, 54.4-65.0%, and 53.7-63.8% in the four WWTPs, respectively. The biological treatment was the predominant process responsible for the removal of DOC, THMFP, and HAAFP in WWTPs. Differences in the reduction of UV-254 were not significant (p > 0.05) among biochemical reaction pool, secondary sedimentation tank, and disinfection tank. Biological aerated filter and suspended carrier activated sludge processes achieved higher DOM removal than the conventional active sludge and anaerobic-anoxic-oxic processes. Hydrophobic neutral and hydrophilic fraction were removed to a higher degree through biological treatment than the other three DOM fractions. HAAFP removal was more efficient than THMFP reduction during biological treatment. During primary treatment, fluorescent materials in secondary sedimentation tanks were preferentially removed, as compared to the bulk DOM. Humic-like fluorescent compounds were not readily eliminated during biological treatment. The fluorescent materials were more susceptible to chlorine than nonfluorescent compounds. Copyright © 2017. Published by Elsevier Ltd.

The effect of mixed oxidants and powdered activated carbon on the removal of natural organic matter.

PubMed

Alvarez-Uriarte, Jon I; Iriarte-Velasco, Unai; Chimeno-Alanís, Noemí; González-Velasco, Juan R

2010-09-15

Present paper studies the influence of electrochemically generated mixed oxidants on the physicochemical properties of natural organic matter, and especially from the disinfection by-products formation point of view. The study was carried out in a full scale water treatment plant. Results indicate that mixed oxidants favor humic to non-humic conversion of natural organic matter. Primary treatment preferentially removes the more hydrophobic fraction. This converted the non-humic fraction in an important source of disinfection by-products with a 20% contribution to the final trihalomethane formation potential (THMFP(F)) of the finished water. Enhanced coagulation at 40 mg l(-1) of polyaluminium chloride with a moderate mixing intensity (80 rpm) and pH of 6.0 units doubled the removal efficiency of THMFP(F) achieved at full scale plant. However, gel permeation chromatography data revealed that low molecular weight fractions were still hardly removed. Addition of small amounts of powdered activated carbon, 50 mg l(-1), allowed reduction of coagulant dose by 50% whereas removal of THMFP(F) was maintained or even increased. In systems where mixed oxidants are used addition of powdered activated carbon allows complementary benefits by a further reduction in the THMFP(F) compared to the conventional only coagulation-flocculation-settling process. Copyright 2010 Elsevier B.V. All rights reserved.

Oxytetracycline removal from water by novel microbial embedding gel beads

NASA Astrophysics Data System (ADS)

Wu, Nan; Pan, Peng; Zeng, Ming; Wang, Wei; Xu, Chenshan; Zhang, Zongpeng; Liu, Xinyuan; Wang, Yichao

2018-01-01

As a common antibiotic in aquatic environment, excessive oxytetracycline (OTC) is urgent to be removed due to its great biological toxicity. Compared with the traditional activated sludge, microbial embedding can enhance the treating efficiency. In this study, novel microbial embedding gel beads were produced with the additional agent of cyclodextrin (CD). Results show that CD could increase the mass transfer of OTC into gel beads, possibly because of its strong affinity for organic matters. In terms of OTC biodegradation, gel beads with CD were comparable to gel beads without CD, while the former’s sucrose removal efficiency was higher than the latter. The biodegradation of OTC only occurred in the presence of sucrose. The respiration test also confirmed these findings. Overall, the produced novel gel beads modified with CD could improve the removal performance of OTC.

Adsorption of selected emerging contaminants onto PAC and GAC: Equilibrium isotherms, kinetics, and effect of the water matrix.

PubMed

Real, Francisco J; Benitez, F Javier; Acero, Juan L; Casas, Francisco

2017-07-03

The removal of three emerging contaminants (ECs) (amitriptyline hydrochloride (AH), methyl salicylate (MS) and 2-phenoxyethanol (PE)) dissolved in several water matrices by means of their adsorption onto powdered activated carbon (PAC) and granular activated carbon (GAC) has been investigated. When dissolved in ultrapure water, adsorption of the ECs followed the trend of AH > MS > PE, with a positive effect of the adsorbent dose. According to the analysis of the adsorption isotherms and adsorption kinetics, PAC showed strongly higher adsorption efficiency in both capacity and velocity of the adsorption, in agreement with its higher mesoporosity. Equilibrium isotherm data were fitted by Langmuir and Freundlich models. Pseudo-second order kinetics modeled very successfully the adsorption process. Finally, the effect of the presence of dissolved organic matter (DOM) in the water matrices (ultrapure water, surface water and two effluents from wastewater treatment plants) on the adsorption of the selected ECs onto PAC was established, as well as its performance on the removal of water quality parameters. Results show a negative effect of the DOM content on the adsorption efficiency. Over 50% of organic matter was removed with high PAC doses, revealing that adsorption onto PAC is an effective technology to remove both micro-pollutants and DOM from water matrices.

Using quartz sand to enhance the removal efficiency of M. aeruginosa by inorganic coagulant and achieve satisfactory settling efficiency.

PubMed

Pei, Haiyan; Jin, Yan; Xu, Hangzhou; Ma, Chunxia; Sun, Jiongming; Li, Hongmin

2017-10-19

In this study, low-cost and non-polluting quartz sand was respectively mixed with AlCl 3 , FeCl 3 and PAFC to synergistically remove Microcystis aeruginosa. Results showed that quartz sand could markedly increase the algae removal efficiency and decrease the coagulant doses. The increase of removal efficiency with AlCl 3 and FeCl 3 was only due to the enhancement of floc density by the quartz sand. However, the removal efficiency with PAFC was increased not only by the enhanced floc density, but also by the enlarged floc size. Flocs from 50 mg/L sand addition were larger than that with other sand doses, which was on account of the appropriate enhancement of collision efficiency at this dose. After coagulation, the extracellular organic matter (EOM) and microcystins (MCs) in system with quartz sand was remarkably reduced. That's because quartz sand can enhance the coagulation so as to improve capping the EOM and MCs in flocs during coagulation process. Owing to 200 mg/L quartz sand could damage the cell's membrane during coagulation proces, algal cells in the system lysed two days earlier than with 50 mg/L sand during flocs storage. In addition, cells with PAFC incurred relatively moderate cellular oxidative damage and could remain intact for longer time.

Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review.

PubMed

Sillanpää, Mika; Ncibi, Mohamed Chaker; Matilainen, Anu; Vepsäläinen, Mikko

2018-01-01

Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs). Nonetheless, with the increased fluctuation of NOM in water (concentration and composition), the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH), developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

PM Removal Efficiency from Diesel Gensets Equipped with Aftermarket Control Devices

EPA Science Inventory

Diesel particulate matter (PM) has been associated with adverse health effects in humans and is classified as a human carcinogen. Additionally, diesel PM, particularly the strongly light absorbing fraction, black carbon (BC), is an important climate forcer. These adverse impact...

Emissions Removal Efficiency from Diesel Gensets Using Aftermarket PM Controls

EPA Science Inventory

Diesel particulate matter (PM) has been associated with adverse health effects in humans and is classified as a human carcinogen. Additionally, diesel PM, particularly the strongly light absorbing fraction, black carbon (BC), is an important climate forcer. The adverse impacts ...

Evaluation of adsorbent and ion exchange resins for removal of organic matter from petroleum refinery wastewaters aiming to increase water reuse.

PubMed

de Abreu Domingos, Rodrigo; da Fonseca, Fabiana Valéria

2018-05-15

The oil refinery industry seeks solutions to reduce its water uptake and consumption by encouraging the reuse of internal streams and wastewater from treatment systems. After conventional treatment the petroleum refinery wastewater still contains a considerable quantity of recalcitrant organics and the adsorption on activated carbon is currently used in Brazilian refineries, although it is still expensive due to the difficulty of its regeneration. This study evaluated the use of adsorbent and ion exchange resins for the removal of organic matter from refinery wastewater after conventional treatment in order to verify its feasibility, applying successive resin regenerations and comparing the results with those obtained for activated carbon process. Adsorption isotherms experiments were used to evaluate commercial resins, and the most efficient was subjected to column experiments, where absorbance (ABS) and total organic carbon (TOC) removal were measured. The adsorption isotherm of the best resin showed an adsorptive capacity that was 55% lower than that of activated carbon. On the other hand, the column experiments indicated good removal efficiency, and the amount of TOC in the treated wastewater was as good as has been reported in the literature for activated carbon. The regeneration efficiency of the retained organics ranged from 57 to 94%, while regenerant consumption ranged from 12 to 79% above the amount recommended by the resin supplier for the removal of organic material from natural sources, showing the great resistance of these recalcitrant compounds to desorption. Finally, an estimate of the service life of the resin using intermediate regeneration conditions found it to be seven times higher than that of activated carbon when the latter is not regenerated. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Remediation efficiency of lead-contaminated soil at an industrial site by ultrasonic-assisted chemical extraction].

PubMed

Wang, Xin-jie; Huang, Jin-lou; Liu, Zhi-qiang; Yue, Xi

2013-09-01

This research chose five lead-contaminated sites of a lead-acid battery factory to analyze the speciation distribution and concentration of lead. Under the same conditions (0.1 mol x L(-1) EDTA,30 min, 25 degrees C), the removal effect of heavy metal was compared between ultrasonic-assisted chemical extraction (UCE) and conventional chemical extraction ( CCE), and the variation of lead speciation was further explored. The results showed that the lead removal efficiency of UCE was significantly better than CCE. The lead removal efficiency of WS, A, B, C and BZ was 10.06%, 48.29%, 48.69%, 53.28% and 36.26% under CCE. While the removal efficiency of the UCE was 22.42%, 69.31%, 71.00%, 74.49% and 71.58%, with the average efficiency higher by 22%. By comparing the speciation distribution of the two washing methods, it was found that the acid extractable content maintained or decreased after UCE, whereas it showed an increasing trend after CCE. The reduction effect of the reducible was as high as 98% by UCE. UCE also showed a more efficient reduction effect of the organic matter-sulfite bounded form and the residual form. Hence, it is feasible to improve the washing efficiency of heavy metal contained in soil by conducting the cleaning process with the help of ultrasonic wave, which is a simple and fast mean to remove lead from contaminated sites.

The influence of thermal treatment on bioweathering and arsenic sorption capacity of a natural iron (oxyhydr)oxide-based adsorbent.

PubMed

Debiec, Klaudia; Rzepa, Grzegorz; Bajda, Tomasz; Zych, Lukasz; Krzysztoforski, Jan; Sklodowska, Aleksandra; Drewniak, Lukasz

2017-12-01

Adsorption plays a significant role in remediation of waters contaminated with arsenic, but the efficiency of the process varies depending on the sorbent properties. Bog iron ores (BIOs), characterized by high sorption capacity and widespread availability, seem to be an optimal sorbent of arsenic. However, the use of BIOs for arsenic removal from waters may be limited by the high amount of organic matter, which may stimulate microbial activity, and thus decomposition of the sorbent. The aim of this study was to determine the effect of organic matter removal by thermal transformation (roasting) on the bioavailability of BIOs and their arsenic sorption capacity. For this purpose, the influence of bacterial growth and activity on untreated and treated BIOs, unloaded and loaded with arsenic, was studied. Moreover, the chemical and physical properties (including FTIR and desorption of arsenic) of BIOs were investigated as well. The results show that the removal of organic matter increases the stability of BIOs, and thus reduces the bioavailability of the immobilized arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Linking the mobilization of dissolved organic matter in catchments and its removal in drinking water treatment to its molecular characteristics.

PubMed

Raeke, Julia; Lechtenfeld, Oliver J; Tittel, Jörg; Oosterwoud, Marieke R; Bornmann, Katrin; Reemtsma, Thorsten

2017-04-15

Drinking water reservoirs in the Northern Hemisphere are largely affected by the decadal-long increase in riverine dissolved organic carbon (DOC) concentrations. The removal of DOC in drinking water treatment is costly and predictions are needed to link DOC removal efficiency to its mobilization in catchments, both of which are determined by the molecular composition. To study the effect of hydrological events and land use on the molecular characteristics of dissolved organic matter (DOM), 36 samples from three different catchment areas in the German low mountain ranges, with DOC concentrations ranging from 3 to 32 mg L -1 , were examined. Additionally, nine pairs of samples from downstream drinking water reservoirs were analyzed before and after flocculation. The molecular composition and the age of DOM were analyzed using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and radiocarbon ( 14 C) analysis. At elevated discharge in a forested catchment comparatively younger, more oxygenated and unsaturated molecules of higher molecular weight were preferentially mobilized, likely linked to the reductive mobilization of iron. DOM with highly similar molecular characteristics (O/C ratio > 0.5, m/z > 500) could also be efficiently removed through flocculation in drinking water treatment. The proportion of DOM removed through flocculation ranged between 43% and 73% of DOC and was highest at elevated discharge. In catchment areas with a higher percentage of grassland and agriculture a higher proportion of DOM molecules containing sulfur and nitrogen was detected, which in turn could be less efficiently flocculated. Altogether, it was shown that DOM that is released during large hydrological events can be efficiently flocculated again, suggesting a reversal of similar chemical mechanisms in both processes. Since the occurrence of heavy rainfall events is predicted to increase in the future, event-driven mobilization of DOC may continue to challenge drinking water production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combined mesophilic anaerobic and thermophilic aerobic digestion process for high-strength food wastewater to increase removal efficiency and reduce sludge discharge.

PubMed

Jang, H M; Park, S K; Ha, J H; Park, J M

2014-01-01

In this study, a process that combines the mesophilic anaerobic digestion (MAD) process with thermophilic aerobic digestion (TAD) for high-strength food wastewater (FWW) treatment was developed to examine the removal of organic matter and methane production. All effluent discharged from the MAD process was separated into solid and liquid portions. The liquid part was discarded and the sludge part was passed to the TAD process for further degradation. Then, the digested sludge from the TAD process was recycled back to the MAD unit to achieve low sludge discharge from the combined process. The reactor combination was operated in two phases: during Phase I, 40 d of total hydraulic retention time (HRT) was applied; during Phase II, 20 d was applied. HRT of the TAD process was fixed at 5 d. For a comparison, a control process (single-stage MAD) was operated with the same HRTs of the combined process. Our results indicated that the combined process showed over 90% total solids, volatile solids and chemical oxygen demand removal efficiencies. In addition, the combined process showed a significantly higher methane production rate than that of the control process. Consequently, the experimental data demonstrated that the combined MAD-TAD process was successfully employed for high-strength FWW treatment with highly efficient organic matter reduction and methane production.

AnSBBR applied to organic matter and sulfate removal: interaction effect between feed strategy and COD/sulfate ratio.

PubMed

Friedl, Gregor F; Mockaitis, Gustavo; Rodrigues, José A D; Ratusznei, Suzana M; Zaiat, Marcelo; Foresti, Eugênio

2009-10-01

A mechanically stirred anaerobic sequencing batch reactor containing anaerobic biomass immobilized on polyurethane foam cubes, treating low-strength synthetic wastewater (500 mg COD L(-1)), was operated under different operational conditions to assess the removal of organic matter and sulfate. These conditions were related to fill time, defined by the following feed strategies: batch mode of 10 min, fed-batch mode of 3 h and fed-batch mode of 6 h, and COD/[SO(4)(2-)] ratios of 1.34, 0.67, and 0.34 defined by organic matter concentration of 500 mg COD L(-1) and sulfate concentrations of 373, 746, and 1,493 mg SO(4)(2-) L(-1) in the influent. Thus, nine assays were performed to investigate the influence of each of these parameters, as well as the interaction effect, on the performance of the system. The reactor operated with agitation of 400 rpm, total volume of 4.0 L, and treated 2.0 L synthetic wastewater in 8-h cycles at 30 +/- 1 degrees C. During all assays, the reactor showed operational stability in relation to the monitored variables such as COD, sulfate, sulfide, sulfite, volatile acids, bicarbonate alkalinity, and solids, thus demonstrating the potential to apply this technology to the combined removal of organic matter and sulfate. In general, the results showed that the 3-h fed-batch operation with a COD/[SO(4)(2-)] ratio of 0.34 presented the best conditions for organic matter removal (89%). The best efficiency for sulfate removal (71%) was accomplished during the assay with a COD/[SO(4)(2-)] ratio of 1.34 and a fill time of 6 h. It was also observed that as fill time and sulfate concentration in the influent increased, the ratio between removed sulfate load and removed organic load also increased. However, it should be pointed out that the aim of this study was not to optimize the removal of organic matter and sulfate, but rather to analyze the behavior of the reactor during the different feed strategies and applied COD/[SO(4)(2-)] ratios, and mainly to analyze the interaction effect, an aspect that has not yet been explored in the literature for batch reactors.

Optimization of urban wastewater treatment plants process with low C/N ratio

NASA Astrophysics Data System (ADS)

Zheng, L.; Xu, G. M.; Chen, J.; Chen, B.; Lv, Z.; Yang, Y. A.

2016-08-01

In southern China, the inflow of water to wastewater treatment plants has a lower concentration of organic matter. This causes treatment plants to face issues in the denitrification and phosphorus removal processes such as deficient carbon sources, high energy consumption, and unstable nitrogen removal. To resolve these issues, we propose the reconstruction of the internal reflux port, improvement of the internal reflux ratio to 200%, the addition of carbon source to anoxic zone, and the addition of phosphorus removal agents in secondary settling tank. The results of study show significantly improved efficiency of nitrogen and phosphorus removal, which ensures the stability of subsequent supply of reused water.

Influence of filling ratio and carrier type on organic matter removal in a moving bed biofilm reactor with pretreatment of electrocoagulation in wastewater treatment.

PubMed

Lopez-Lopez, C; Martín-Pascual, J; González-Martínez, A; Calderón, K; González-López, J; Hontoria, E; Poyatos, J M

2012-01-01

At present, there is great concern about limited water resources and water quality, which require a more advanced technology. The Moving Bed Biofilm Reactor (MBBR) has been shown to be an efficient technology for removal of organic matter and nutrients in industrial and urban wastewater treatment. However, there are some pollutants which are more difficult to remove by biological processes, so this process can be improved with additional physical and chemical treatments such as electrocoagulation, which appears to be a promising technology in electrochemical treatments. In this research, urban wastewater was treated in an MBBR plant with an electrocoagulation pre-treatment. K1 from AnoxKaldnes and AQWISE ABC5 from Aqwise were the carriers studied under three different filling ratios (20, 35, and 50%). The experimental pilot plant had four bioreactors with 20 L of operation volume and a common feed tank with 100 L of operation volume. The movement of the carriers was generated by aeration and stirrer systems. Organic matter removal was studied by analysis of soluble chemical oxygen demand (sCOD). The maximum organic matter removal in this MBBR system was 65.8% ± 1.4% and 78.4% ± 0.1% for K1 and Aqwise ABC5 carriers, respectively. Moreover, the bacterial diversity of the biofilm was studied by temperature-gradient gel electrophoresis (TGGE) of PCR-amplified partial 16S rRNA genes. 20 prominent TGGE bands were successfully reamplified and sequenced, being the predominant population: β-Proteobacteria, α-Proteobacteria, and Actinobacteria.

Study on the removal efficiency of UF membranes using bacteriophages in bench-scale and semi-technical scale.

PubMed

Kreissel, K; Bösl, M; Lipp, P; Franzreb, M; Hambsch, B

2012-01-01

To determine the removal efficiency of ultrafiltration (UF) membranes for nano-particles in the size range of viruses the state of the art uses challenge tests with virus-spiked water. This work focuses on bench-scale and semi-technical scale experiments. Different experimental parameters influencing the removal efficiency of the tested UF membrane modules were analyzed and evaluated for bench- and semi-technical scale experiments. Organic matter in the water matrix highly influenced the removal of the tested bacteriophages MS2 and phiX174. Less membrane fouling (low ΔTMP) led to a reduced phage reduction. Increased flux positively affected phage removal in natural waters. The tested bacteriophages MS2 and phiX174 revealed different removal properties. MS2, which is widely used as a model organism to determine virus removal efficiencies of membranes, mostly showed a better removal than phiX174 for the natural water qualities tested. It seems that MS2 is possibly a less conservative surrogate for human enteric virus removal than phiX174. In bench-scale experiments log removal values (LRV) for MS2 of 2.5-6.0 and of 2.5-4.5 for phiX174 were obtained for the examined range of parameters. Phage removal obtained with differently fabricated semi-technical modules was quite variable for comparable parameter settings, indicating that module fabrication can lead to differing results. Potting temperature and module size were identified as influencing factors. In conclusion, careful attention has to be paid to the choice of experimental settings and module potting when using bench-scale or semi-technical scale experiments for UF membrane challenge tests.

Application of response surface methodology for optimization of natural organic matter degradation by UV/H2O2 advanced oxidation process

PubMed Central

2014-01-01

Background In this research, the removal of natural organic matter from aqueous solutions using advanced oxidation processes (UV/H2O2) was evaluated. Therefore, the response surface methodology and Box-Behnken design matrix were employed to design the experiments and to determine the optimal conditions. The effects of various parameters such as initial concentration of H2O2 (100–180 mg/L), pH (3–11), time (10–30 min) and initial total organic carbon (TOC) concentration (4–10 mg/L) were studied. Results Analysis of variance (ANOVA), revealed a good agreement between experimental data and proposed quadratic polynomial model (R2 = 0.98). Experimental results showed that with increasing H2O2 concentration, time and decreasing in initial TOC concentration, TOC removal efficiency was increased. Neutral and nearly acidic pH values also improved the TOC removal. Accordingly, the TOC removal efficiency of 78.02% in terms of the independent variables including H2O2 concentration (100 mg/L), pH (6.12), time (22.42 min) and initial TOC concentration (4 mg/L) were optimized. Further confirmation tests under optimal conditions showed a 76.50% of TOC removal and confirmed that the model is accordance with the experiments. In addition TOC removal for natural water based on response surface methodology optimum condition was 62.15%. Conclusions This study showed that response surface methodology based on Box-Behnken method is a useful tool for optimizing the operating parameters for TOC removal using UV/H2O2 process. PMID:24735555

Migration and distribution of sodium ions and organic matters during electro-dewatering of waste activated sludge at different dosages of sodium sulfate.

PubMed

Xiao, Jun; Wu, Xu; Yu, Wenbo; Liang, Sha; Yu, Jiangwei; Gu, Yueyuan; Deng, Huali; Hu, Jiukun; Xiao, Keke; Yang, Jiakuan

2017-12-01

In this study, the influence of Na 2 SO 4 on electro-dewatering (EDW) of waste activated sludge (WAS) was investigated. The highest water removal efficiency of 42.5% was achieved at the optimum Na 2 SO 4 dosage of 12.5 g kg -1 DS during EDW process at a constant voltage of 20 V. The migration and distribution of water, organic matters and Na + at different Na 2 SO 4 dosages were investigated through layered experiments. The results indicated the entire EDW process followed the S curve model, and it can be divided into three stages: (1) initial desalination stage: at the initial few min of EDW process, the rate of electroosmosis was extremely slow while electromigration of ions like Na + was intense, and the electromigration was more obvious with increased Na 2 SO 4 dosage; (2) dewatering stage: the dewatering efficiency increased dramatically via electroosmosis; (3) the dewaterability limit stage: the maximum value of dewatering efficiency has been achieved, while the water removal efficiency and dry solids content remained constant. During the EDW process, the possible electrolysis resulted in a pH gradient in the sludge cake. With the addition of Na 2 SO 4 in the EDW, the pH gradient was intensified, and the migration rate of organic matters moving from cathode to anode increased while compared with the raw WAS. This study provided insights into the mechanism of EDW process at different dosages of Na 2 SO 4 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Pecan shell-based granular activated carbon for treatment of chemical oxygen demand (COD) in municipal wastewater.

PubMed

Bansode, R R; Losso, J N; Marshall, W E; Rao, R M; Portier, R J

2004-09-01

The present investigation was undertaken to compare the adsorption efficiency of pecan shell-based granular activated carbon with the adsorption efficiency of the commercial carbon Filtrasorb 200 with respect to uptake of the organic components responsible for the chemical oxygen demand (COD) of municipal wastewater. Adsorption efficiencies for these two sets of carbons (experimental and commercial) were analyzed by the Freundlich adsorption model. The results indicate that steam-activated and acid-activated pecan shell-based carbons had higher adsorption for organic matter measured as COD, than carbon dioxide-activated pecan shell-based carbon or Filtrasorb 200 at all the carbon dosages used during the experiment. The higher adsorption may be related to surface area as the two carbons with the highest surface area also had the highest organic matter adsorption. These results show that granular activated carbons made from agricultural waste (pecan shells) can be used with greater effectiveness for organic matter removal from municipal wastewater than a coal-based commercial carbon. Copyright 2004 Elsevier Ltd.

Identification of organic compounds in landfill leachate treated by advanced oxidation processes.

PubMed

Scandelai, Ana Paula Jambers; Sloboda Rigobello, Eliane; Oliveira, Beatriz Lopes Corso de; Tavares, Célia Regina Granhen

2017-11-27

Landfill leachates are considered to be complex effluents of a variable composition containing many biorecalcitrant and highly toxic compounds. Considering the shortage of studies concerning the treatment of landfill leachates using ozone, as well as its combination with catalysts, the aim of this paper was to identify the organic compounds in this effluent treated with advanced oxidation processes (AOPs) of ozonation (O 3 ), and heterogeneous catalytic ozonation with TiO 2 (O 3 /TiO 2 ) and with ZnO (O 3 /ZnO). In addition, this study sought to assess the efficiency of the removal of the organic matter present in the leachate. For the pre- and post-AOPs, the leachate was characterized through physicochemical parameters and identification of organic compounds using gas chromatography coupled to the mass spectrometry (GC-MS). The three processes studied (O 3 , O 3 /TiO 2 , and O 3 /ZnO) presented color removal, turbidity, BOD above 95%, and lower COD removals (19%, 24%, and 33%, respectively). All AOPs studied promoted a similar reduction of organic compounds from leachate, some of which with toxic and carcinogenic potential, such as p-cresol, bisphenol A, atrazine, and hexazinone. In addition, upon the removal of organic matter and organic compounds, the heterogeneous catalytic ozonation processes proved more efficient than the process carried out only with ozone.

Assessing the effectiveness of pollutant removal by macrophytes in a floating wetland for wastewater treatment

NASA Astrophysics Data System (ADS)

Prajapati, Meera; van Bruggen, Johan J. A.; Dalu, Tatenda; Malla, Rabin

2017-12-01

The study aimed to evaluate the removal of pollutants by floating treatment wetlands (FTWs) using an edible floating plant, and emergent macrophytes. All experiments were performed under ambient conditions. Physico-chemical parameters were measured, along with microbiological analysis of biofilm within the roots, water column, and sludge and gravel zone. Nitrification and denitrification rates were high in the water zone of Azolla filiculoides, Lemna minor, Lactuca sativa, P. stratiotes, and Phragmites australis. Phosphate removal efficiencies were 23, 10, and 15% for the free-floating hydrophytes, emergent macrophytes, and control and edible plants, respectively. The microbial community was relatively more active in the root zone compared to other zones. Pistia stratiotes was found to be the efficient in ammonium (70%) and total nitrogen (59%) removal. Pistia stratiotes also showed the highest microbial activity of 1306 mg day-1, which was 62% of the total volume. Microbial activity was found in the water zone of all FTWs expect for P. australis. The use of P. stratiotes and the edible plant L. sativa could be a potential option to treat domestic wastewater due to relatively high nutrient and organic matter removal efficiency.

Removal of fly-ash and dust particulate matters from syngas produced by gasification of coal by using a multi-stage dual-flow sieve plate wet scrubber.

PubMed

Kurella, Swamy; Meikap, Bhim Charan

2016-08-23

In this work, fly-ash water scrubbing experiments were conducted in a three-stage lab-scale dual-flow sieve plate scrubber to observe the performance of scrubber in fly-ash removal at different operating conditions by varying the liquid rate, gas rate and inlet fly-ash loading. The percentage of fly-ash removal efficiency increases with increase in inlet fly-ash loading, gas flow rate and liquid flow rate, and height of the scrubber; 98.55% maximum percentage of fly-ash removal efficiency (ηFA) is achieved at 19.36 × 10(-4) Nm(3)/s gas flow rate (QG) and 48.183 × 10(-6) m(3)/s liquid flow rate (QL) at 25 × 10(-3) kg/Nm(3) inlet fly-ash loading (CFA,i). A model has also been developed for the prediction of fly-ash removal efficiency of the column using the experimental results. The predicted values calculated using the correlation matched well with the experimental results. Deviations observed between the experimental and the predicted values were less than 20%.

A modified UCT method for biological nutrient removal: configuration and performance.

PubMed

Vaiopoulou, E; Aivasidis, A

2008-07-01

A pilot-scale prototype activated sludge system is presented, which combines both, the idea of University of Cape Town (UCT) concept and the step denitrification cascade for removal of carbon, nitrogen and phosphorus. The experimental set-up consists of an anaerobic selector and stepwise feeding in subsequent three identical pairs of anoxic and oxic tanks. Raw wastewater with influent flow rates ranging between 48 and 168 l d(-1) was fed to the unit at hydraulic residence times (HRTs) of 5-18 h and was distributed at percentages of 60/25/15%, 40/30/30% and 25/40/35% to the anaerobic selector, 2nd and 3rd anoxic tanks, respectively (influent flow distribution before the anaerobic selector). The results for the entire experimental period showed high removal efficiencies of organic matter of 89% as total chemical oxygen demand removal and 95% removal for biochemical oxygen demand, 90% removal of total Kjeldahl nitrogen and total nitrogen removal through denitrification of 73%, mean phosphorus removal of 67%, as well as excellent settleability. The highest removal efficiency and the optimum performance were recorded at an HRT of about 9h and influent flow rate of 96 l d(-1), in which 60% is distributed to the anaerobic selector, 25% to the second anoxic tank and 15% to the last anoxic tank. Consequently, the plant configuration enhanced removal efficiency, optimized performance, saved energy, formed good settling sludge and provided operational assurance.

Potential for enhancement of aerobic biological removal of recalcitrant organic matter in bleached pulp mill effluents.

PubMed

Mounteer, A H; Souza, L C; Silva, C M

2007-02-01

Increasingly stringent effluent quality limits for bleached kraft pulp mills pose a great challenge to mill wastewater system managers since these limits can require levels of chemical oxygen demand (COD) removal efficiency rarely reported for biological treatment of these types of effluents. The present study was therefore undertaken to better understand the nature of recalcitrant COD in bleached kraft pulp effluents that persists through the biological treatment system. Bleaching effluents from a Brazilian eucalypt bleached kraft pulp mill were collected and treated in a bench-scale sequencing batch reactor. Organic matter in raw and treated effluents was characterized before and after separation into low and high molecular mass fractions. Biological treatment removed 71% of the COD, with 83% removal of the low molecular mass COD but only 36% removal of the high molecular mass COD. Microorganisms capable of degrading the recalcitrant COD were isolated from enrichment cultures of the original activated sludge fed on fractions of the bleaching effluent that presented low biodegradabilities. Use of a microbial consortium composed of ten of these isolates to treat the biologically treated effluent removed a further 12% of the effluent COD, all from the high molecular mass fraction. Results of this research indicate that microorganisms with potential for degrading recalcitrant COD are present in activated sludge, but that these are not metabolically active during normal activated sludge treatment of mill effluents. The use of biological selectors in the treatment system to promote growth of such microorganisms may enhance removal of recalcitrant organic matter.

Removing Organic Matter and Nutrients from Pig Farm Wastewater with a Constructed Wetland System

PubMed Central

De La Mora-Orozco, Celia; González-Acuña, Irma Julieta; Saucedo-Terán, Ruben Alfonso; Flores-López, Hugo Ernesto; Rubio-Arias, Hector Osbaldo; Ochoa-Rivero, Jesús Manuel

2018-01-01

Pollutants from pig farms in Mexico have caused problems in many surface water reservoirs. Growing concern has driven the search for low-cost wastewater treatment solutions. The objective of this research was to evaluate the potential of an in-series constructed wetland to remove nutrients from wastewater from a pig farm. The wetland system had a horizontal flow that consisted of three cells, the first a surface water wetland, the second a sedimentation cell, and the third a subsurface flow wetland. The vegetation used was Thypa sp. and Scirpus sp. A mix of soil with red volcanic rock (10–30 mm diameter) and yellow sand (2–8 mm diameter) was used as a substrate for the vegetation. The experiments were carried out in duplicate. Water samples were collected at the inflow and outflow of the cells. Two hydraulic retention times (HRT) (5 and 10 days) and three treatments were evaluated: 400, 800, and 1200 mg·L−1 of chemical oxygen demand (COD) concentration. Data was collected in situ for temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), and total dissolved solids (TDS). COD, total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH3–N), and total phosphorous (TP) were analyzed in the laboratory. The results showed that the in-series constructed wetland is a feasible system for nutrient pollutant removal, with COD removal efficiency of 76% and 80% mg·L−1 for a 5- and 10-day HRT, respectively. The removal efficiency for TKN, NH3–N, and TP reached about 70% with a 5-day HRT, while a removal of 85% was obtained with a 10-day HRT. The wetland reached the maximum removal efficiency with a 10-day HRT and an inflow load of 400 mg·L−1 of organic matter. The results indicate that HRT positively affects removal efficiency of COD and TDS. On the other hand, the HRT was not the determining factor for TP removal. Treatment one, with an initial COD concentration of 400 mg·L−1, had the highest removal of the assessed pollutants, allowing for the use of water for irrigation according to Mexican regulatory standards (NOM-001). The water quality resulting from treatments two and three (T2 = 800 mg·L−1 of COD and T3 = 1200 mg·L−1 of COD) did not comply with minimal requirements for irrigation water. PMID:29883370

Treatment of HMX-production wastewater in an aerobic granular reactor.

PubMed

Zhang, Jin-Hua; Wang, Min-Hui; Zhu, Xiao-Meng

2013-04-01

Aerobic granules were applied to the treatment of HMX-production wastewater using a gradual domestication method in a SBR. During the process, the granules showed a good settling ability, a high biomass retention rate, and high biological activity. After 40 days of stable operation, aerobic granular sludge performed very effectively in the removal of carbon and nitrogen compounds from HMX-production wastewater. Organic matter removal rates up to 97.57% and nitrogen removal efficiencies up to 80% were achieved during the process. Researchers conclude that using aerobic granules to treat explosive wastewater has good prospects for success.

Removal of High -Concentration and Refractory Organic Matter from Diosgenin Manufacture Wastewater : a case study of a demonstration project in Hubei Province, P R China

NASA Astrophysics Data System (ADS)

Bao, J.; Wang, L.

2009-12-01

Wastewater from diosgenin manufacture is dark brown (3,500 ~4,000 times of the chroma) and acidic(pH=0.8~1.5)with high concentration of organic matter(COD=25,000~38,000 mg/L)and poor biodegradability(BOD5/COD= 0.25~0.30). It is highly toxic to biota due to the water-soluble saponin, tannins and pectin. Therefore removal of the organic matter is of great importance before the discharge of the wastewater into the environment. Here we presented a set of data from a demonstration project in Hubei province, P R China with an improved technics. This technics, focusing on the treatment of diosgenin wastewater, included hydrolytic acidification, internal electrolysis, neutralization, aerating-improved Up-flow Anaerobic Sludge Bed (UASB) and bio-contact oxidation treatment in sequence to remove the organic matter. After 60 days of starting-up, the water quality from hydrolytic acidification reactor was greatly improved. The effluent became clear, indicating the obvious removal of suspended solids in the water; the ratio of BOD/COD increased to 0.44, suggesting an significant increase of biodegradability; the content of volatile fatty acid (VFA) increased from 22.6 mmol/L to 86.8 mmol/L and the volume loading of COD reached 9.48 kg COD/(m3d). Basically at this stage the removal efficiency of COD was stabilized at 25%. Further treatment was conducted on the effluent from hydrolytic acidification reactor through the Improved UASB Reactor after the internal electrolysis and neutralization. The Improved UASB Reactor can start up at room temperature with an influent of 1,500 mg/L COD and inflow rate of 50(m3/d). Then, temperature was increased gradually to 38 oC (± 2 oC) to optimize the growth of the mesophilic anaerobes in the reactor. The content of VFA of the effluent was controlled below 8 mmol/L to guarantee the pH in the range of 6.8~7.2. After 150 days of debugging, the COD of the influent to UASB increased to 9,600 mg/L, hydraulic retaining time (HRT) was around 70 hrs , the volume loading and the removal efficiency of COD reached 3.42 kg COD/(m3.d) and 75% respectively. Bio-contact oxidation process dealt with the effluent from the Improved UASB at room temperature. The HRT was 54 hrs and dissolved oxygen was controlled between 2 to 4 mg/L. Currently, the COD volume loading reached 1.05 kg COD/(m3.d) and the removal efficiency of COD was over 90%. The total removal efficiencies of COD and color were over 99% and 98% respectively in the overall process. The pH, color and COD content of the final effluent were 7, about 200 mg/L and 50 times of the chroma respectively. All these indexes met the criteria of “The National Discharge Standard of Industry Water Pollutants for Sapogenin”(GB 20425-2006). This work was supported by National Key Technologies R&D Program No. 2006BAB04A14-2), the Hubei Provincial Science and Technology Department (No. 2006AA305A05) and Wuhan Science and Technology Bureau (20066002101).

Achieving mainstream nitrogen removal through simultaneous partial nitrification, anammox and denitrification process in an integrated fixed film activated sludge reactor.

PubMed

Wang, Chao; Liu, Sitong; Xu, Xiaochen; Zhang, Chaolei; Wang, Dong; Yang, Fenglin

2018-07-01

The anaerobic ammonium oxidation (anammox) is becoming a critical technology for energy neutral in mainstream wastewater treatment. However, the presence of chemical oxygen demanding in influent would result in a poor nitrogen removal efficiency during the deammonification process. In this study, the simultaneous partial nitrification, anammox and denitrification process (SNAD) for mainstream nitrogen removal was investigated in an integrated fixed film activated sludge (IFAS) reactor. SNAD-IFAS process achieved a total nitrogen (TN) removal efficiency of 72 ± 2% and an average COD removal efficiency was 88%. The optimum COD/N ratio for mainstream wastewater treatment was 1.2 ± 0.2. Illumina sequencing analysis and activity tests showed that anammox and denitrifying bacteria were the dominant nitrogen removal microorganism in the biofilm and the high COD/N ratios (≥2.0) leaded to the proliferation of heterotrophic bacteria (Hydrogenophaga) and nitrite-oxidizing bacteria (Nitrospira) in the suspended sludge. Network analysis confirmed that anammox bacteria (Candidatus Kuenenia) could survive in organic matter environment due to that anammox bacteria displayed significant co-occurrence through positive correlations with some heterotrophic bacteria (Limnobacter) which could protect anammox bacteria from hostile environments. Overall, the results of this study provided more comprehensive information regarding the community composition and assemblies in SNAD-IFAS process for mainstream nitrogen removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of Removal Mechanisms in a Graphene Oxide-Coated Ceramic Ultrafiltration Membrane for Retention of Natural Organic Matter, Pharmaceuticals, and Inorganic Salts.

PubMed

Chu, Kyoung Hoon; Fathizadeh, Mahdi; Yu, Miao; Flora, Joseph R V; Jang, Am; Jang, Min; Park, Chang Min; Yoo, Sung Soo; Her, Namguk; Yoon, Yeomin

2017-11-22

Functionalized graphene oxide (GO), derived from pure graphite via the modified Hummer method, was used to modify commercially available ceramic ultrafiltration membranes using the vacuum method. The modified ceramic membrane functionalized with GO (ceramic GO ) was characterized using a variety of analysis techniques and exhibited higher hydrophilicity and increased negative charge compared with the pristine ceramic membrane. Although the pure water permeability of the ceramic GO membrane (14.4-58.6 L/m 2 h/bar) was slightly lower than that of the pristine membrane (25.1-62.7 L/m 2 h/bar), the removal efficiencies associated with hydrophobic attraction and charge effects were improved significantly after GO coating. Additionally, solute transport in the GO nanosheets of the ceramic GO membrane played a vital role in the retention of target compounds: natural organic matter (NOM; humic acid and tannic acid), pharmaceuticals (ibuprofen and sulfamethoxazole), and inorganic salts (NaCl, Na 2 SO 4 , CaCl 2 , and CaSO 4 ). While the retention efficiencies of NOM, pharmaceuticals, and inorganic salts in the pristine membrane were 74.6%, 15.3%, and 2.9%, respectively, these increased to 93.5%, 51.0%, and 31.4% for the ceramic GO membrane. Consequently, the improved removal mechanisms of the membrane modified with functionalized GO nanosheets can provide efficient retention for water treatment under suboptimal environmental conditions of pH and ionic strength.

Variables affecting efficiency of molasses fermentation wastewater ozonation.

PubMed

Coca, M; Peña, M; González, G

2005-09-01

The main operating variables affecting ozonation efficiencies of wastewater from beet molasses alcoholic fermentation have been studied. Semibatch experiments have been performed in order to analyze the influence of pH, bicarbonate ion, temperature and stirring rate on color and organic matter removals. The efficiencies were similar regardless of the pH, which indicates that direct reactions of ozone with wastewater organics were predominant to radical reactions. Gel permeation chromatography confirmed the reduction in the concentration of organics absorbing light at 475 nm after ozonation. The elimination of bicarbonate ion, strong inhibitor of hydroxyl radical reactions, yielded an improvement in both color and COD reduction efficiencies. Acidification for removing bicarbonate ions produced a shift of colored compounds to smaller molecular weights. The highest efficiencies were achieved at 40 degrees C. Color and COD reductions at 40 degrees C were about 90% and 37%, respectively. In no case, the percentage of TOC removed was higher than 10-15%. Stirring rate had a slightly positive effect during the first stage of the ozonation showing that mass transfer played a role only during the initial reaction phase when direct attack of ozone molecules to aromatic/olefinic structures of colored substances was the predominant pathway.

Treatment of soil eluate containing nitro aromatic compounds by adsorption on activated coke (AC).

PubMed

Zhang, Yiping; Jiang, Zhenming; Zhao, Quanlin; Zhang, Zhenzhong; Su, Hongping; Gao, Xuewen; Ye, Zhengfang

2016-01-01

Soil washing is a kind of physical method to remove organic matters from contaminated soil. However, its eluate after washing may result in secondary pollution to the environment. In this study, activated coke (AC) was used to remove organic pollutants from contaminated soil eluate. The effect of temperature, initial chemical oxygen demand (COD) and AC dosage on COD removal efficiency was investigated. The results showed that the organic matter can be removed in the eluate because the COD dropped a lot. When the AC dosage was 20 g·L(-1), 88.92% of COD decreased after 480 min of adsorption at 50 °C. The process of adsorption can be described by the Redlich-Peterson isotherm. The adsorption was spontaneous and endothermic. The pseudo-second-order model can be used to describe the adsorption process. After adsorption, the acute toxicity of the eluate was reduced by 76%, and the water qualities were in agreement with Chinese discharge standard GB 14470.1-2002, which means the eluate could be discharged to the environment.

[Effect of UV Light Radiation on the Coagulation of Chlorella and Its Mechanism].

PubMed

Wang, Wen-dong; Zhang, Ke; Xu, Hong-bin; Liu, Guo-qi

2016-01-15

Considering algae were difficult to be effectively removed in conventional water treatment process, UV radiation was used to enhance the coagulation of algae in this study. The results showed that with the increase of radiation time, the removal rates of both algae and turbidity experienced a decrease after an increase, and reached their maximum values at 50 min. When the dosage of PAC was 5 mg x L(-1), the removal rates of algae and turbidity of the radiated sample were 20.1% and 18% higher than the blank sample, respectively. When pH ranged from 6 to 9, the coagulation efficiency varied little. At pH 8 and with a radiation time of 50 min, the removal rates of algae and turbidity reached 93.5% and 90.6%, respectively. Meanwhile, the Zeta potential reached the maximum, and the algae generated extracellular organic matter, which favored the subsequent coagulation. After radiated for 60 min, the algal cells was destroyed, leading to a release of intracellular organic matter into the solution. Accordingly, the Zeta potential decreased, which had a negative effect on the subsequent coagulation process.

Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

PubMed

dos Santos, Elisama Vieira; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo; Rodrigo, Manuel Andres

2016-04-15

In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

An anaerobic membrane bioreactor - membrane distillation hybrid system for energy recovery and water reuse: Removal performance of organic carbon, nutrients, and trace organic contaminants.

PubMed

Song, Xiaoye; Luo, Wenhai; McDonald, James; Khan, Stuart J; Hai, Faisal I; Price, William E; Nghiem, Long D

2018-07-01

In this study, a direct contact membrane distillation (MD) unit was integrated with an anaerobic membrane bioreactor (AnMBR) to simultaneously recover energy and produce high quality water for reuse from wastewater. Results show that AnMBR could produce 0.3-0.5L/g COD added biogas with a stable methane content of approximately 65%. By integrating MD with AnMBR, bulk organic matter and phosphate were almost completely removed. The removal of the 26 selected trace organic contaminants by AnMBR was compound specific, but the MD process could complement AnMBR removal, leading to an overall efficiency from 76% to complete removal by the integrated system. The results also show that, due to complete retention, organic matter (such as humic-like and protein-like substances) and inorganic salts accumulated in the MD feed solution and therefore resulted in significant fouling of the MD unit. As a result, the water flux of the MD process decreased continuously. Nevertheless, membrane pore wetting was not observed throughout the operation. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

40 CFR 63.305 - Alternative standards for coke oven doors equipped with sheds.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SOURCE CATEGORIES National Emission Standards for Coke Oven Batteries § 63.305 Alternative standards for coke oven doors equipped with sheds. (a) The owner or operator of a new or existing coke oven battery... the efficiency of the control device for removal of particulate matter by conducting measurements at...

40 CFR 63.305 - Alternative standards for coke oven doors equipped with sheds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SOURCE CATEGORIES National Emission Standards for Coke Oven Batteries § 63.305 Alternative standards for coke oven doors equipped with sheds. (a) The owner or operator of a new or existing coke oven battery... the efficiency of the control device for removal of particulate matter by conducting measurements at...

40 CFR 63.305 - Alternative standards for coke oven doors equipped with sheds.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SOURCE CATEGORIES National Emission Standards for Coke Oven Batteries § 63.305 Alternative standards for coke oven doors equipped with sheds. (a) The owner or operator of a new or existing coke oven battery... the efficiency of the control device for removal of particulate matter by conducting measurements at...

40 CFR 63.305 - Alternative standards for coke oven doors equipped with sheds.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SOURCE CATEGORIES National Emission Standards for Coke Oven Batteries § 63.305 Alternative standards for coke oven doors equipped with sheds. (a) The owner or operator of a new or existing coke oven battery... the efficiency of the control device for removal of particulate matter by conducting measurements at...

40 CFR 63.305 - Alternative standards for coke oven doors equipped with sheds.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SOURCE CATEGORIES National Emission Standards for Coke Oven Batteries § 63.305 Alternative standards for coke oven doors equipped with sheds. (a) The owner or operator of a new or existing coke oven battery... the efficiency of the control device for removal of particulate matter by conducting measurements at...

Removal of contaminants and pathogens from secondary effluents using intermittent sand filters.

PubMed

Bali, Mahmoud; Gueddari, Moncef; Boukchina, Rachid

2011-01-01

Intermittent infiltration percolation of wastewater through unsaturated sand bed is an extensive treatment technique aimed at eliminating organic matter, oxidizing ammonium and removing pathogens. The main purpose of this study was to determine the depuration efficiencies of a sand filter to remove contaminants from secondary wastewater effluents. Elimination of pathogenic bacteria (total and faecal coliforms, streptococci) and their relationship with the filter depth were investigated. Results showed a high capacity of infiltration percolation process to treat secondary effluents. Total elimination of suspended solids was obtained. Mean removal rate of BOD(5) and COD was more than 97 and more than 81%, respectively. Other water quality parameters such as NH(4)-N, TKN and PO(4)-P showed significant reduction except NO(3)-N which increased significantly in the filtered water. Efficiency of pathogenic bacteria removal was shown to mainly depend on the filter depth. Average reductions of 2.35 log total coliforms, 2.47 log faecal coliforms and 2.11 log faecal streptococci were obtained. The experimental study has shown the influence of the temperature on the output purification of infiltration percolation process.

Coagulation of micro-polluted Pearl River water with IPF-PACls.

PubMed

Xu, Yi; Sun, Wei; Wang, Dong-sheng; Tang, Hong-xiao

2004-01-01

Water samples collected from early March 2001 to the end of April 2002 at the branch of Pearl River around the Guangzhou City were analyzed for its micro-polluted characteristics. The coagulation behavior of polyaluminum chlorides (PACls) was then examined focusing on the effect of primary water quality and speciation distribution. The results showed that PACls exhibit better coagulation efficiency than alum in accordance with the different speciation. The turbidity removal property of PACls is evidently better than alum at low dosage. While in neutral zone (about 6.5-7.5), the turbidity removal of PACls decreases owing to the restabilization of particles at higher dosage. The organic matters in raw water exhibit marked influence on coagulation. In acidic zone, organic matters complex with polymer species and promote the formation of flocs. With an increase in pH, the complexation of organics with polymer species gradually decreases, and the removal of organics mainly depends on adsorption. The effect is evidently improved with the raise of B value.

Removal of natural organic matter from drinking water by advanced oxidation processes.

PubMed

Matilainen, Anu; Sillanpää, Mika

2010-06-01

Over the past 10-20years the amount of the natural organic matter (NOM) has been increased in raw water supplies on several areas. The presence of NOM causes many problems in drinking water treatment processes, including: (i) negative effect on water quality by colour, taste and odor problems, (ii) increased coagulant and disinfectant dose requirements (which in turn results increased sludge and potential harmful disinfection by-product formation), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. Thus, more efficient methods for the removal of NOM have emerged. Among these are advanced oxidation processes (AOPs). These include O(3)/H(2)O(2), O(3)/UV, UV/H(2)O(2), TiO(2)/UV, H(2)O(2)/catalyst, Fenton and photo-Fenton prosesses as well as ultrasound. In the present work, an overview of the recent research studies dealing with AOP methods for the removal of NOM and related compounds from drinking water is presented.

Influence of sludge age on the performance of MFC treating winery wastewater.

PubMed

Penteado, Eduardo D; Fernandez-Marchante, Carmen Maria; Zaiat, Marcelo; Cañizares, Pablo; Gonzalez, Ernesto Rafael; Rodrigo, Manuel Andrés

2016-05-01

The objective of this paper was to determine the influence of sludge age on microbial fuel cell (MFC) performance for generating electricity and removing organic matter from winery wastewater. Six Solid Retention Times (SRT) were used: 1.2, 1.4, 1.8, 2.3, 3.5 and 7.0 d. Results demonstrate that the electricity generation increases by decreasing the SRT, selecting electrogenic microorganisms, once the specific organic loading rate (SOLR) increased and the competition for substrate was reduced. Decreasing the SRT, coulombic efficiency can be increased from 3.4% to almost 42.2% and maximum power density from 58 to 890 mW m(-2). However the SRT did not influence on organic matter removal in biological treatment, because only a small part of COD was removed oscillating around 600 mg L(-1) d(-1)and it was very similar at all SRT studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product, in drinking water treatment process and its toxicity on zebrafish.

PubMed

Lin, Tao; Zhou, Dongju; Yu, Shilin; Chen, Wei

2016-09-01

The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product (DBP) in conventional drinking water treatment plant (C-DWTP) and advanced DWTP (ADWTP) was studied with newly maximum formation potential (MFP) process. It was demonstrated that the advanced treatment displayed greater removal efficiency towards DCAcAm formation potential (MFP) than the conventional treatment. The hydrophilic natural organic matter and natural organic matter with molecular weight <1 kDa or >10 kDa leaded to more DCAcAm formation, and the aromatic protein was inferred as one part of DCAcAm precursor. DCAcAm was found to cause delayed development and malformation to zebrafish embryos at embryonic growth stage. Compared with heart toxicity, it caused a significant neuron toxicity. It also could cause the acute DNA damage to adult zebrafish, which should be extremely cautioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dynamic pesticide removal with activated carbon fibers.

PubMed

Martín-Gullón, I; Font, R

2001-02-01

Rapid small-scale minicolumn tests were carried out to simulate the atrazine adsorption in water phase with three pelletized pitch-based activated carbon fibers (ACF) and one commercial granular activated carbon (GAC). Initial atrazine solutions were prepared with pretreated ground water. Minicolumn tests showed that the performance of highly activated carbon fibers (surface area of 1700 m2/g) is around 7 times better than the commercial GAC (with surface area at around 1100 m2/g), whereas carbon fibers with medium activation degree (surface area of 1500 m2/g) had a removal efficiency worse than the commercial carbon. The high removal efficiency of the highly activated ACF is due to the wide-opened microstructure of the material, with an appreciable contribution of the low size mesopores, maintaining at these conditions a fast kinetic adsorption rate rather than a selective adsorbent for micropollutants vs. natural organic matter.

Efficient Utilization of Waste Carbon Source for Advanced Nitrogen Removal of Landfill Leachate

PubMed Central

Yin, Wenjun; Tan, Fengxun

2017-01-01

A modified single sequencing batch reactor (SBR) was developed to remove the nitrogen of the real landfill leachate in this study. To take the full advantage of the SBR, stir phase was added before and after aeration, respectively. The new mechanism in this experiment could improve the removal of nitrogen efficiently by the utilization of carbon source in the raw leachate. This experiment adopts the SBR process to dispose of the real leachate, in which the COD and ammonia nitrogen concentrations were about 3800 mg/L and 1000 mg/L, respectively. Results showed that the removal rates of COD and total nitrogen were above 85% and 95%, respectively, and the effluent COD and total nitrogen were less than 500 mg/L and 40 mg/L under the condition of not adding any carbon source. Also, the specific nitrogen removal rate was 1.48 mgN/(h·gvss). In this process, polyhydroxyalkanoate (PHA) as a critical factor for the highly efficient nitrogen removal (>95%) was approved to be the primary carbon source in the sludge. Because most of the organic matter in raw water was used for denitrification, in the duration of this 160-day experiment, zero discharge of sludge was realized when the effluent suspended solids were 30–50 mg/L. PMID:29435456

Efficiencies of multilayer infiltration systems for the removal of urban runoff pollutants.

PubMed

Hou, Lizhu; Liu, Fang; Feng, Chuanping; Wan, Li

2013-01-01

Current rates of urban development will result in water runoff becoming a major complication of urban water pollution. To address the worsening situation regarding water resource shortage and pollution, novel multilayer infiltration systems were designed and their effectiveness for removing pollutants in urban runoff tested experimentally. The multilayer infiltration systems effectively removed most pollutants, including organic matter (chemical oxygen demand (CODCr)), total nitrogen (TN), ammonia-nitrogen (NH4(+)-N) and total phosphorus (TP). CODCr, TN, NH4(+)-N, and TP were reduced by 68.67, 23.98, 82.66 and 92.11%, respectively. The main mechanism for nitrogen removal was biological nitrogen removal through nitrification and denitrification. Phosphorus in the urban runoff was removed mainly by fixation processes in the soil, such as adsorption and chemical precipitation. The results indicate that the proposed novel system has potential for removal of pollutants from urban runoff and subsequent reuse of the treated water.

PAEs and BPA removal in landfill leachate with Fenton process and its relationship with leachate DOM composition.

PubMed

He, Pin-Jing; Zheng, Zhong; Zhang, Hua; Shao, Li-Ming; Tang, Qiong-Yao

2009-08-15

An increasing attention has been paid to the trace endocrine disrupting compounds (EDCs) in landfill leachate. In this paper, the removal of EDCs including phthalic acid esters (PAEs) and bisphenol A (BPA) from the fresh and mature landfill leachate by Fenton treatment was studied. More than 40% of PAEs and about 62% of BPA were removed from the raw mature leachate while only 20% of PAEs and 37% of BPA in the raw fresh leachate were reduced, respectively. After the fresh and mature leachates were spiked with PAEs to 1.5 mg L(-1) and BPA to 0.08 mg L(-1), the removal efficiencies of BPA and PAEs increased to more than 88%. The results indicated that the removing efficiencies of the EDCs in the leachate had a relationship with their concentrations, and that the trace levels of EDCs in leachate challenged the treatment capacity of the Fenton process. Most of the EDCs in the enriched leachate were removed by oxidation, which had no clear correlation with the hydrophobicity of the EDCs. The flocculation played an important role in the removal of di-(2-ethylhexyl) phthalate that could not be completely oxidized in the Fenton process, in that the EDCs with high n-octanol/water partition coefficient inclined to precipitate after the Fenton process. The dissolved organic matter (DOM) in the fresh leachate inhibited the EDCs removal more than the DOM in the mature leachate did. Both the composition of the leachate DOM and the characteristics of the EDCs determined the removing efficiencies of the EDCs in the Fenton process.

Removal of organic pollutants from produced water using Fenton oxidation

NASA Astrophysics Data System (ADS)

Afzal, Talia; Hasnain Isa, Mohamed; Mustafa, Muhammad Raza ul

2018-03-01

Produced water (PW) is the largest stream of wastewater from oil and gas exploration. It is highly polluted and requires proper treatment before disposal. The main objective of this study was to investigate the effectiveness of Fenton oxidation in degradation of organic matter in PW. The role of operating factors viz., H2O2 concentration (0.12 × 10-3 moles/L to 3 moles/L), [H2O2]/[Fe2+] molar ratio (2 to 75), and reaction time (30 to 200 minutes), on COD removal was determined through a series of batch experiments conducted in acidic environment at room temperature. The experiments were conducted with 500 mL PW samples in 1L glass beakers covered on the outside with aluminum foil to protect them from sunlight. Pre-decided amounts of ferrous sulfate heptahydrate (FeSO4.7H2O) and hydrogen peroxide (H2O2) were added to initiate the Fenton reaction. An increase in COD removal was observed with increase in reaction time and [H2O2]/[Fe2+] molar ratio. COD removal also increased with H2O2 concentration up to 0.01 moles/L; further increase in H2O2 concentration decreased the COD removal efficiency. Over 90% COD removal was achieved under optimum reaction conditions. The study indicates that Fenton oxidation is effective for remediation of PW in terms of organic matter removal.

Evaluation of simultaneous organic matters and nutrients removal from municipal wastewater using a novel bioreactor (D-A2O) system.

PubMed

Ye, Changbing; Zhou, Zhiming; Li, Ming; Liu, Qin; Xu, Tiantian; Li, Jia

2018-07-15

A novel bioreactor, the divisional influent dual-anaerobic-anoxic/oxic (D-A 2 O) system, was applied to treat municipal wastewater. This new system improved the removal efficiency of simultaneous organic matters and nutrients, and provided a reduction in the system's energy costs and sludge yield. Results from the reactor's 18 months of operation demonstrated the following optimal conditions for the 4 key parameters of the system: (1) a divisional ratio (DR) of 8:2 between the influent flow volumes fed into the anaerobic and anoxic tanks, (2) a hydraulic retention time (HRT) of 6 h, (3) a R:r ratio of 200%:100% between the mixed liquor return ratio (R) and the return activated sludge ratio (r), and (4) an alternative operating time (t A/B ) of 1 h for the A/B anaerobic-anoxia series. Under optimal conditions, the system showed a high removal efficiency for the chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH 3 -N), and total phosphorus (TP) removals, with the average removal efficiencies (with a standard deviation of less than 3%) being 95.23%, 80.64%, 90.42%, and 90.03%, respectively. The final concentration ranges of COD, TN, NH 3 -N, and TP in the effluent were 26-48 mg L -1 , 6.11-11.03 mg L -1 , 2.93-4.04 mg L -1 , and 0.21-0.45 mg L -1 , respectively. The concentrations of the pollutants in the effluent from the D-A 2 O system were lower than those required for Level 1A (Chinese quality of wastewater discharge standard GB18918-2002). According to the results, we concluded that the divisional influent dual-anaerobic-anoxic system (which integrated the A 2 O and sequencing batch reactor (SBR) process) was successfully provided sufficient carbon sources for denitrification and phosphorus uptake without external carbon addition. Compared to the conventional anaerobic-anoxic/oxic (A 2 O) process, the D-A 2 O system offers a high removal efficiency, simple operation, and significant energy saving of about 0.276 kWh m -3 based on the volume of the treated water. Therefore, the new D-A 2 O system has a strong potential for use in treatment plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dissolved organic matter removal during coal slag additive soil aquifer treatment for secondary effluent recharging: Contribution of aerobic biodegradation.

PubMed

Wei, Liangliang; Li, Siliang; Noguera, Daniel R; Qin, Kena; Jiang, Junqiu; Zhao, Qingliang; Kong, Xiangjuan; Cui, Fuyi

2015-06-01

Recycling wastewater treatment plant (WWTP) effluent at low cost via the soil aquifer treatment (SAT), which has been considered as a renewable approach in regenerating potable and non-potable water, is welcome in arid and semi-arid regions throughout the world. In this study, the effect of a coal slag additive on the bulk removal of the dissolved organic matter (DOM) in WWTP effluent during SAT operation was explored via the matrix configurations of both coal slag layer and natural soil layer. Azide inhibition and XAD-resins fractionation experiments indicated that the appropriate configuration designing of an upper soil layer (25 cm) and a mixture of soil/coal slag underneath would enhance the removal efficiency of adsorption and anaerobic biodegradation to the same level as that of aerobic biodegradation (31.7% vs 32.2%), while it was only 29.4% compared with the aerobic biodegradation during traditional 50 cm soil column operation. The added coal slag would preferentially adsorb the hydrophobic DOM, and those adsorbed organics could be partially biodegraded by the biomass within the SAT systems. Compared with the relatively lower dissolved organic carbon (DOC), ultraviolet light adsorption at 254 nm (UV-254) and trihalomethane formation potential (THMFP) removal rate of the original soil column (42.0%, 32.9%, and 28.0%, respectively), SSL2 and SSL4 columns would enhance the bulk removal efficiency to more than 60%. Moreover, a coal slag additive in the SAT columns could decline the aromatic components (fulvic-like organics and tryptophan-like proteins) significantly. Copyright © 2015 Elsevier Ltd. All rights reserved.

Terbuthylazine and desethylterbuthylazine: Recent occurrence, mobility and removal techniques.

PubMed

Tasca, Andrea Luca; Puccini, Monica; Fletcher, Ashleigh

2018-07-01

The herbicide terbuthylazine (TBA) has displaced atrazine in most of EU countries, becoming one of the most regularly used pesticides and, therefore, frequently detected in natural waters. The affinity of TBA for soil organic matter suggests prolonged contamination; degradation leads to the release of the metabolite desethylterbuthylazine (DET), which has higher water solubility and binds more weakly to organic matter compared to the parent compound, resulting in higher associated risk for contamination of groundwater resources. Additionally, TBA and DET are chemicals of emerging concern because of their persistence and toxicity towards aquatic organisms; moreover, they are known to have significant endocrine disruption capacity to wildlife and humans. Conventional treatments applied during drinking water production do not lead to the complete removal of these chemicals; activated carbon provides the greatest efficiency, whereas ozonation can generate by-products with comparable oestrogenic activity to atrazine. Hydrogen peroxide alone is ineffective to degrade TBA, while UV/H 2 O 2 advanced oxidation and photocatalysis are the most effective processes for oxidation of TBA. It has been determined that direct photolysis gives the highest degradation efficiency of all UV/H 2 O 2 treatments, while most of the photocatalytic degradation is attributed to OH radicals, and TiO 2 solar-photocatalytic ozonation can lead to almost complete TBA removal in ∼30 min. Constructed wetlands provide a valuable buffer capacity, protecting downstream surface waters from contaminated runoff. TBA and DET occurrence are summarized and removal techniques are critically evaluated and compared, to provide the reader with a comprehensive guide to state-of-the-art TBA removal and potential future treatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of feed characteristics on the organic matter, nitrogen and phosphorus removal in an activated sludge system treating piggery slurry.

PubMed

González, C; García, P A; Muñoz, R

2009-01-01

Piggery wastewater is characterized by its high content in nitrogen and phosphorus, as well as by a low C/N ratio. This type of wastewater is traditionally spread to croplands (with its subsequent leaching to groundwater) or rarely discharged into natural water bodies, which ultimately cause severe episodes of eutrophication in aquatic ecosystems. In this context, activated sludge systems constitute a robust and efficient treatment option. The performance of an activated sludge process using a pre-denitrification configuration treating both sieved and flocculated swine slurry at a hydraulic retention time (HRT) of 7.7 days was evaluated. In order to avoid bacterial wash-out, sludge from the settler was recirculated to the anoxic tank to accomplish denitrification. Once the biomass was acclimatized, the reactor was fed with swine slurry containing 19, 2.6, and 0.27 g/L of total chemical oxygen demand (COD), total Kjeldhal nitrogen (TKN), and soluble P, respectively. Nitrogen removal showed a clear dependency on the influent composition. When the influent TKN/total COD and soluble COD/total COD ratios were respectively 0.12-0.15 and 0.7, the reactor exhibited good removal efficiencies (up to 99 and 91 for N-NH(4)(+), TKN, respectively) while PO(4)(3-) was removed up to 65%. However, when the influent TKN/total COD ratio rose to 0.26 and soluble COD/total COD decreased to 0.3, the denitrification process was severely hindered concomitant with and accumulation of nitrite. Nevertheless, organic matter degradation was not affected by influent composition. At the last stage of the experiment, removals of dissolved phosphorus fell to 40% when the redox potential (ORP) profile showed a constant value of -400 mV, likely due to phosphate released from bacterial sludge.

Performance of ceramic ultrafiltration membranes and fouling behavior of a dye-polysaccharide binary system.

PubMed

Zuriaga-Agustí, E; Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I; Mendoza-Roca, J A

2014-05-01

Ultrafiltration membrane processes have become an established technology in the treatment and reuse of secondary effluents. Nevertheless, membrane fouling arises as a major obstacle in the efficient operation of these systems. In the current study, the performance of tubular ultrafiltration ceramic membranes was evaluated according to the roles exerted by membrane pore size, transmembrane pressure and feed concentration on a binary foulant system simulating textile wastewater. For that purpose, carboxymethyl cellulose sodium salt (CMC) and an azo dye were used as colloidal and organic foulants, respectively. Results showed that a larger pore size enabled more solutes to get adsorbed into the pores, producing a sharp permeate flux decline attributed to the rapid pore blockage. Besides, an increase in CMC concentration enhanced severe fouling in the case of the tighter membrane. Concerning separation efficiency, organic matter was almost completely removed with removal efficiency above 98.5%. Regarding the dye, 93% of rejection was achieved. Comparable removal efficiencies were attributed to the dynamic membrane formed by the cake layer, which governed process performance in terms of rejection and selectivity. As a result, none of the evaluated parameters showed significant influence on separation efficiency, supporting the significant role of cake layer on filtration process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removal of steroid estrogens from wastewater using granular activated carbon: comparison between virgin and reactivated carbon.

PubMed

Rowsell, Victoria Francesca; Pang, Dawn Sok Cheng; Tsafou, Foteini; Voulvoulis, Nikolaos

2009-04-01

This research was set up in response to new European legislation to identify cost-effective treatment for removal of steroid estrogens from effluent. This study aimed to compare estrogen removal of two types of granular activated carbon: virgin (F400) and reactivated (C401) carbon. Rapid, small-scale column tests were conducted with a total bed volume of 24.9 cm3 over three columns, and analysis was carried out using high-performance liquid chromatography. Results demonstrated that C401 performed more efficiently with greater than or equal to 81% estrogen removal in wastewater compared to F400 which produced greater than or equal to 65% estrogen removal. Estrogen removal can be affected by competitive adsorption from natural organic matter present in wastewater. In addition, the physical properties of each carbon had the potential to influence adsorption differently, thus resulting in the observed varied adsorption capability of the two carbons.

PbO2(s, plattnerite) reductive dissolution by natural organic matter: reductant and inhibitory subfractions.

PubMed

Shi, Zhi; Stone, Alan T

2009-05-15

Natural organic matter (NOM) is a diverse collection of molecules, each possessing its own reductant, complexant, and adsorption properties. Here, we are interested in the ability of NOM to bring about the reductive dissolution of Pb(IV)O2(s). Adding the coagulants FeCl3 or Al2(SO4)3 followed by membrane filtration is one way to remove a subset of NOM molecules from surface water samples. Another is to pass water samples through a granular activated carbon (GAC) column. Results from applying these treatments to Great Dismal Swamp water (DSW) and Nequasset Bog Water (NBW) can best be explained as follows: (i) GAC column treatment is more efficient at removing the NOM fraction most responsible for reductive dissolution. (ii) Coagulation/filtration, with either coagulant, is most efficient at removing a second, inhibitory fraction. Inhibition may arise from (i) adsorption at the mineral/water interface, which blocks approach of reductant molecules and (ii) a micelle-like aggregate nature, which provides hydrophobic pockets that capture reductantmolecules, again keeping them away from the mineral/water interface. Hypotheses regarding reductant and inhibitory fractions are further evaluated using representative low-molecular-weight compounds. Substituted hydroquinones are used as mimics of the reductant fraction, and malonic acid, quinic acid, trehalose, alginic acid, and polygalacturonic acid are used as mimics of the inhibitory fraction.

Environmental Benefit Assessment for the Carbonation Process of Petroleum Coke Fly Ash in a Rotating Packed Bed.

PubMed

Pei, Si-Lu; Pan, Shu-Yuan; Li, Ye-Mei; Chiang, Pen-Chi

2017-09-19

A high-gravity carbonation process was deployed at a petrochemical plant using petroleum coke fly ash and blowdown wastewater to simultaneously mineralized CO 2 and remove nitrogen oxides and particulate matters from the flue gas. With a high-gravity carbonation process, the CO 2 removal efficiency was found to be 95.6%, corresponding to a capture capacity of 600 kg CO 2 per day, at a gas flow rate of 1.47 m 3 /min under ambient temperature and pressure. Moreover, the removal efficiency of nitrogen oxides and particulate matters was 99.1% and 83.2%, respectively. After carbonation, the reacted fly ash was further utilized as supplementary cementitious materials in the blended cement mortar. The results indicated that cement with carbonated fly ash exhibited superior compressive strength (38.1 ± 2.5 MPa at 28 days in 5% substitution ratio) compared to the cement with fresh fly ash. Furthermore, the environmental benefits for the high-gravity carbonation process using fly ash were critically assessed. The energy consumption of the entire high-gravity carbonation ranged from 80 to 169 kWh/t-CO 2 (0.29-0.61 GJ/t-CO 2 ). Compared with the scenarios of business-as-usual and conventional carbon capture and storage plant, the economic benefit from the high-gravity carbonation process was approximately 90 and 74 USD per ton of CO 2 fixation, respectively.

Analysis of contaminants in factor VIII preparations administered to patients with hemophilia.

PubMed Central

Rock, G. A.; Farrah, G.; Rozon, G.; Smiley, R. K.; Cole, R.; Villeneuve, D.; Tittley, P.

1983-01-01

Cryoprecipitate and the more purified factor VIII concentrates are all heterogeneous preparations that contain not only a high concentration of factor VIII but also various other materials, some of which might be injurious, causing liver damage after long-term exposure. The efficiency of three standard cryoprecipitate filters, two microaggregate filters and the appropriate factor VIII concentrate filters in reducing the amount of particulate matter delivered to the patient was assessed. Filtration of cryoprecipitate through the standard filters removed less than 20% of the contaminating microaggregates and very few of the large number of intact platelets, although the total dose of factor VIII was delivered. Microaggregate filters were no better in reducing the platelet contamination, although the total number of particles delivered was halved. However, 25% of the factor VIII was retained in the bed volume of the filter. The concentrate preparations also contained significant amounts of particulate matter that was unrelated to factor VIII and was not removed following filtration through the designated filter. These findings indicate that a new filter should be developed for administration of factor VIII concentrate that would remove the particulate matter while delivering all of the factor VIII to the patient. Images FIG. 1 FIG. 2 FIG. 3 FIG. 5 PMID:6401585

Remediation of Urban River Water by Pontederia Cordata Combined with Artificial Aeration: Organic Matter and Nutrients Removal and Root-Adhered Bacterial Communities.

PubMed

Gu, Dungang; Xu, Huan; He, Yan; Zhao, Feng; Huang, Minsheng

2015-01-01

Macrophyte combined with artificial aeration is a promising in situ remediation approach for urban rivers polluted with nutrients and organic matter. However, seasonal variations and aeration effects on phytoremediation performance and root-adhered microbial communities are still unclear. In this study, Pontederia cordata was used to treat polluted urban river water under various aeration intensities. Results showed that the highest removal efficiencies of chemical oxygen demand (COD(Cr)) and total nitrogen (TN) were attained under aeration of 30 L min(-1) in spring and summer and 15 L min(-1) in autumn, while total phosphorus (TP) removal reached maximum with aeration of 15 L min(-1) in all seasons. Moderate aeration was beneficial for increasing the diversity of root-adhered bacteria communities, and the shift of bacterial community structure was more pronounced in spring and autumn with varying aeration intensity. The dual effect, i.e. turbulence and dissolved oxygen (DO), of aeration on the removal of COD(Cr) and TN prevailed over the individual effect of DO, while DO was the most influential factor for TP removal and the root-adhered bacterial community diversity. P. cordata combined with 15 L min(-1) aeration was deemed to be the best condition tested in this study.

Comprehensive assessment of precursors, diagenesis, and reactivity to water treatment of dissolved and colloidal organic matter

USGS Publications Warehouse

Leenheer, J.A.

2004-01-01

A comprehensive isolation, fractionation, and characterization research approach was developed for dissolved and colloidal organic matter (DOM) in water, and it was applied to various surface- and groundwaters to assess DOM precursors, DOM diagenesis, and DOM reactivity to water treatment processes. Major precursors for natural DOM are amino sugars, condensed tannins, and terpenoids. Amino sugar colloids derived from bacterial cell walls are incompletely removed by drinking water treatment and foul reverse osmosis membranes, but are nearly quantitatively removed by soil/aquifer treatment. When chlorinated, amino sugars produce low yields of regulated disinfection by-products (DBFs) but they produce significant chlorine demand that is likely caused by chlorination of free amino groups. Condensed tannins are major precursors for "blackwater" DOM such as that found in the Suwannee River. This DOM produces high yields of DBPs upon chorination, and is efficiently removed by coagulation/flocculation treatment. Terpenoid-derived DOM appears to be biologically refractory, infiltrates readily into groundwater with little removal by soil/aquifer treatment, gives low DBF-yields upon chlorination and is poorly removed by coagulation/flocculation treatments. Peptides derived from proteins are major components of the base DOM fraction (10% or less of the mass of DOM), and this fraction produces large yields of haloacetonitriles upon chorination.

Enhanced P, N and C removal from domestic wastewater using constructed wetland employing construction solid waste (CSW) as main substrate.

PubMed

Yang, Y; Wang, Z M; Liu, C; Guo, X C

2012-01-01

Construction solid waste (CSW), an inescapable by-product of the construction and demolition process, was used as main substrate in a four-stage vertical subsurface flow constructed wetland system to improve phosphorus P removal from domestic wastewater. A 'tidal flow' operation was also employed in the treatment system. Under a hydraulic loading rate (HLR) of 0.76 m3/m2 d for 1st and 3rd stage and HLR of 0.04 m3/m2 d for 2nd and 4th stage of the constructed wetland system respectively and tidal flow operation strategy, average removal efficiencies of 99.4% for P, 95.4% for ammoniacal-nitrogen, 56.5% for total nitrogen and 84.5% for total chemical oxygen demand were achieved during the operation period. The CSW-based constructed wetland system presents excellent P removal performance. The adoption of tidal flow strategy creates the aerobic/anoxic condition intermittently in the treatment system. This can achieve better oxygen transfer and hence lead to more complete nitrification and organic matter removal and enhanced denitrification. Overall, the CSW-based tidal flow constructed wetland system holds great promise for enabling high rate removal of P, ammoniacal-nitrogen and organic matter from domestic wastewater, and transforms CSW from a waste into a useful material.

Removal of dissolved organic matter in municipal effluent with ozonation, slow sand filtration and nanofiltration as high quality pre-treatment option for artificial groundwater recharge.

PubMed

Linlin, Wu; Xuan, Zhao; Meng, Zhang

2011-04-01

In the paper the combination process of ozonation, slow sand filtration (SSF) and nanofiltration (NF) was investigated with respect to dissolved organic matter (DOM) removal as high quality pre-treatment option for artificial groundwater recharge. With the help of ozonation leading to breakdown of the large organic molecules, SSF preferentially removes soluble microbial by-product-like substances and DOM with molecular weight (MW) less than 1.0 kDa. NF, however, removes aromatic, humic acid-like and fulvic acid-like substances efficiently and specially removes DOM with MW above 1.0 kDa. The residual DOM of the membrane permeate is dominated by small organics with MW 500 Da, which can be further reduced by the aquifer treatment, despite of the very low concentration. Consequently, the O(3)/SSF/NF system offers a complementary process in DOM removal. Dissolved organic carbon (DOC) and trihalomethane formation potential (THMFP) can be reduced from 6.5±1.1 to 0.7±0.3 mg L(-1) and from 267±24 to 52±6 μg L(-1), respectively. The very low DOC concentration of 0.6±0.2 mg L(-1) and THMFP of 44±4 μg L(-1) can be reached after the aquifer treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Simultaneous Removal of Nitrate and Natural Organic Matter from Drinking Water Using a Hybrid Heterotrophic/Autotrophic/Biological Activated Carbon Bioreactor

PubMed Central

Saeedi, Reza; Naddafi, Kazem; Nabizadeh, Ramin; Mesdaghinia, Alireza; Nasseri, Simin; Alimohammadi, Mahmood; Nazmara, Shahrokh

2012-01-01

Abstract Simultaneous removal of nitrate (\\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes {10} {9} {7} {6}\\begin{document} $${\\rm NO}_3^{-}$$ \\end{document}) and natural organic matter (NOM) from drinking water using a hybrid heterotrophic/autotrophic/BAC bioreactor (HHABB) was studied in continuous mode. The HHABB consisted of three compartments: ethanol heterotrophic part, sulfur autotrophic part, and biological activated carbon (BAC)-part (including anoxic and aerobic sections). Experiments were performed with \\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes {10} {9} {7} {6}\\begin{document} $${\\rm NO}_3^{-}$$ \\end{document} concentration 30 mg N/L, \\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes {10} {9} {7} {6}\\begin{document} $${\\rm NO}_3^{-}$$ \\end{document} loading rate 0.72 kg N/m3/d, C : N ratio 0.53, and three concentrations of NOM (0.6, 2.6, and 5.7 mg C/L). Overall denitrification rate and efficiency of the HHABB were not affected by NOM concentration and were in the suitable ranges of 0.69–0.70 kg N/m3/d and 96.0%–97.7%, respectively. NOM removal at concentration 0.6 mg C/L was not efficient because of organic carbon replacement as soluble microbial products. At higher NOM concentrations, total NOM removal efficiencies were 55%–65%, 55%–70%, and 55%–65% for dissolved organic carbon, trihalomethane formation potential, and UV absorbance at 254 nm (UV254), respectively. The more efficient compartments of the HHABB for the removal of NOM were the ethanol heterotrophic phase and aerobic BAC-phase. The efficiency of the HHABB in the removal of NOM was considerable, and the effluent dissolved organic carbon and trihalomethane formation potential concentrations were relatively low. This study indicated that the HHABB without the anoxic BAC-phase could be a feasible alternative for simultaneous removal of \\documentclass{aastex}\\usepackage{amsbsy}\\usepackage{amsfonts}\\usepackage{amssymb}\\usepackage{bm}\\usepackage{mathrsfs}\\usepackage{pifont}\\usepackage{stmaryrd}\\usepackage{textcomp}\\usepackage{portland, xspace}\\usepackage{amsmath, amsxtra}\\pagestyle{empty}\\DeclareMathSizes {10} {9} {7} {6}\\begin{document} $${\\rm NO}_3^{-}$$ \\end{document} and NOM from drinking water at full scale. PMID:22479146

The effect of different surface materials on runoff quality in permeable pavement systems.

PubMed

Li, Haiyan; Li, Zhifei; Zhang, Xiaoran; Li, Zhuorong; Liu, Dongqing; Li, Tanghu; Zhang, Ziyang

2017-09-01

To investigate the effect of different permeable pavement surface materials on the removal of pollutants from urban storm-runoff, six commonly surface materials (porous asphalt, porous concrete, cement brick, ceramic brick, sand base brick, and shale brick) were selected in this study and the research was carried out by column experiments. Except the concentrations of total suspended solids (TSS), chemical oxygen demand (COD), ammonia nitrogen (NH 4 -N), nitrate nitrogen (NO 3 -N), total nitrogen (TN), and total phosphorus (TP) in the influent and effluent that were measured, the removal mechanism of pollutants was discussed further. The results indicate that the surface materials influence the removal efficiency of pollutants greatly and have different effects on certain pollutant. Furthermore, the physical interception and adsorption would be the main mechanism for the removal of pollutants from runoff. For example, for all surface materials, the average removal efficiency of TSS is nearly about 90.0% because of physical interception. Due to the amount of iron oxide, the removal efficiency of COD, NO 3 -N, and TN of shale brick was 88.2, 35.1, and 17.5%, respectively. NH 4 -N and TN can be easily removed by porous asphalt due to the high content of organic matter. By lacking of useful adsorption sites, all the surface materials had little effect on the removal of TP from runoff. This research could offer useful guidelines for the better design of permeable pavement system and promote the insight into the removal mechanism of pollutants in permeable pavement system. Graphical abstract Different types of materials for the different types of pollutants in the runoff purification capacity were significantly different, overall, shale brick and porous asphalt Shale bricks and porous asphalt have a better purification effect according to the six kinds of materials.

Dissolved organic matter and estrogen interactions regulate estrogen removal in the aqueous environment: A review.

PubMed

Ma, Li; Yates, Scott R

2018-06-03

This review summarizes the characterization and quantification of interactions between dissolved organic matter (DOM) and estrogens as well as the effects of DOM on aquatic estrogen removal. DOM interacts with estrogens via binding or sorption mechanisms like π-π interaction and hydrogen bonding. The binding affinity is evaluated in terms of organic-carbon-normalized sorption coefficient (Log K OC ) which varies with types and composition of DOM. DOM has been suggested to be a more efficient sorbent compared with other matrices, such as suspended particulate matter, sediment and soil; likely associated with its large surface area and concentrated carbon content. As a photosensitizer, DOM enhanced estrogen photodegradation when the concentration of DOM was below a threshold value, and when above, the acceleration effect was not observed. DOM played a dual role in affecting biodegradation of estrogens depending on the recalcitrance of the DOM and the nutrition status of the degraders. DOM also acted as an electron shuttle (redox mediator) mediating the degradation of estrogens. DOM hindered enzyme-catalyzed removal of estrogens while enhanced their transformation during the simultaneous photo-enzymatic process. Membrane rejection of estrogens was pronounced for hydrophobic DOM with high aromaticity and phenolic moiety content. Elimination of estrogens via photolysis, biodegradation, enzymolysis and membrane rejection in the presence of DOM is initiated by sorption, accentuating the role of DOM as a mediator in regulating aquatic estrogen removal. Published by Elsevier B.V.

Pilot investigation of two-stage biofiltration for removal of natural organic matter in drinking water treatment.

PubMed

Fu, Jie; Lee, Wan-Ning; Coleman, Clark; Meyer, Melissa; Carter, Jason; Nowack, Kirk; Huang, Ching-Hua

2017-01-01

A pilot study employing two parallel trains of two-stage biofiltration, i.e., a sand/anthracite (SA) biofilter followed by a biologically-active granular activated carbon (GAC) contactor, was conducted to test the efficiency, feasibility and stability of biofiltration for removing natural organic matter (NOM) after coagulation in a drinking water treatment plant. Results showed the biofiltration process could effectively remove turbidity (<0.1 NTU in all effluents) and NOM (>24% of dissolved organic carbon (DOC), >57% of UV 254 , and >44% of SUVA 254 ), where the SA biofilters showed a strong capacity for turbidity removal, while the GAC contactors played the dominant role in NOM removal. The vertical profile of water quality in the GAC contactors indicated the middle-upper portion was the critical zone for the removal of NOM, where relatively higher adsorption and enhanced biological removal were afforded. Fluorescence excitation-emission matrix (EEM) analysis of NOM showed that the GAC contactors effectively decreased the content of humic-like component, while protein-like component was refractory for the biofiltration process. Nutrients (NH 4 -N and PO 4 -P) supplementation applied upstream of one of the two-stage biofiltration trains (called engineered biofiltration) stimulated the growth of microorganisms, and showed a modest effect on promoting the biological removal of small non-aromatic compositions in NOM. Redundancy analysis (RDA) indicated influent UV 254 was the most explanatory water quality parameter for GAC contactors' treatment performance, and a high load of UV 254 would result in significantly reduced removals of UV 254 and SUVA 254 . Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrating Fenton's process and ion exchange for olive mill wastewater treatment and iron recovery.

PubMed

Reis, Patrícia M; Martins, Pedro J M; Martins, Rui C; Gando-Ferreira, Licínio M; Quinta-Ferreira, Rosa M

2018-02-01

A novel integrated methodology involving Fenton's process followed by ion exchange (IE) was proposed for the treatment of olive mill wastewater. Fenton's process was optimized and it was able to remove up to 81% of chemical oxygen demand when pH 3.5, reaction time 1 h, [Fe 2+ ] = 50 mg L -1 and [Fe 2+ ]/[H 2 O 2 ] = 0.002 were applied. In spite of the potential of this treatment approach, final iron removal from the liquid typically entails pH increase and iron sludge production. The integration of an IE procedure using Lewatit TP 207 resin was found to be able to overcome this important environmental shortcoming. The resin showed higher affinity toward Fe 3+ than to Fe 2+ . However, the iron removal efficiency of an effluent coming from Fenton's was independent of the type of the initial iron used in the process. The presence of organic matter had no significant effect over the resin iron removal efficiency. Even if some efficiency decrease was observed when a high initial iron load was applied, the adsorbent mass quantity can be easily adapted to reach the desired iron removal. The use of IE is an interesting industrial approach able to surpass Fenton's peroxidation drawback and will surely boost its full-scale application in the treatment of bio-refractory effluents.

Enhanced permeability, selectivity, and antifouling ability of CNTs/Al2O3 membrane under electrochemical assistance.

PubMed

Fan, Xinfei; Zhao, Huimin; Liu, Yanming; Quan, Xie; Yu, Hongtao; Chen, Shuo

2015-02-17

Membrane filtration provides effective solutions for removing contaminants, but achieving high permeability, good selectivity, and antifouling ability remains a great challenge for existing membrane filtration technologies. In this work, membrane filtration coupled with electrochemistry has been developed to enhance the filtration performance of a CNTs/Al2O3 membrane. The as-prepared CNTs/Al2O3 membrane, obtained by coating interconnected CNTs on an Al2O3 substrate, presented good pore-size tunability, mechanical stability, and electroconductivity. For the removal of a target (silica spheres as a probe) with a size comparable to the membrane pore size, the removal efficiency and flux at +1.5 V were 1.1 and 1.5 times higher, respectively, than those without electrochemical assistance. Moreover, the membrane also exhibited a greatly enhanced removal efficiency for contaminants smaller than the membrane pores, providing enhancements of 4 orders of magnitude and a factor of 5.7 for latex particles and phenol, respectively. These results indicated that both the permeability and the selectivity of CNTs/Al2O3 membranes can be significantly improved by electrochemical assistance, which was further confirmed by the removal of natural organic matter (NOM). The permeate flux and NOM removal efficiency at +1.5 V were about 1.6 and 3.0 times higher, respectively, than those without electrochemical assistance. In addition, the lost flux of the fouled membrane was almost completely recovered by an electrochemically assisted backwashing process.

Effect of organic matter strength on anammox for modified greenhouse turtle breeding wastewater treatment.

PubMed

Chen, Chongjun; Huang, Xiaoxiao; Lei, Chenxiao; Zhang, Tian C; Wu, Weixiang

2013-11-01

Anaerobic ammonium-N removal from modified greenhouse turtle breeding wastewater with different chemical oxygen demand (COD) strengths (194.0-577.8 mg L(-1)) at relatively fixed C/N ratios (≈ 2) was investigated using a lab-scale up-flow anaerobic sludge blanket (UASB) anammox reactor. During the entire experiment, the total nitrogen (TN) removal efficiency was about 85% or higher, while the average COD removal efficiency was around 56.5 ± 7.9%. Based on the nitrogen and carbon balance, the nitrogen removal contribution was 79.6 ± 4.2% for anammox, 12.7 ± 3.0% for denitrification+denitritation and 7.7 ± 4.9% for other mechanisms. Denaturing gradient gel electrophoresis (DGGE) analyses revealed that Planctomycete, Proteobacteria and Chloroflexi bacteria were coexisted in the reactor. Anammox was always dominant when the reactor was fed with different COD concentrations, which indicated the stability of the anammox process with the coexistence of the denitrification process in treating greenhouse turtle breeding wastewater. Copyright © 2013 Elsevier Ltd. All rights reserved.

Organic Matter Composition, Recycling Susceptibility, and the Effectiveness of the Biological Pump – An Evaluation Using NMR Spectra of Marine Plankton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paytan, Adina

Carbon (C) sequestration through fertilization of phytoplankton with micronutrients and enhancement of the absorption and retention of atmospheric C by ocean biota heavily depends on the efficiency of the “biological pump”. The long-term effectiveness of this strategy depends on a net transfer of C from the upper ocean-atmosphere system to the deep ocean where the C is removed from contact with the atmosphere for an extended period of time. This C removal can be equated to the amount of C fixation by phytoplankton minus the C cycling and regeneration in the euphotic zone. If the regeneration efficiency is increased, thenmore » despite increased C fixation, no net loss (sequestration) of C will result. A reduction in cycling efficiency in the euphotic zone, on the other hand, will increase the effectiveness of the “biological pump” and thus C sequestration. The degree of organic matter biodegradation and recycling depends on the “reactivity” of compounds synthesized by the biota, which in turn, is controlled by the structural characteristic of these compounds. There is considerable evidence that different phytoplankton taxa differ substantially in their biogeochemical characteristics and it is likely that the relative abundance of different compounds synthesized by these distinct taxa, and even within each group at different growth conditions, will differ too. This variability in biosynthesis and thus abundance of a wide range of organic compounds in the water column would lend itself to different susceptibility for biodegradation and regeneration. Knowledge of the distribution of various organic matter structural groups synthesized by distinct taxa, the dependence of the organic matter compound classes on different growth conditions (temperature, light, nutrients) and the selective susceptibility of these compound to regeneration is crucial for estimating the potential for rapid regeneration in the euphotic zone, and thus the effectiveness of the “biological pump”.« less

[NH4+-N removal stability of zeolite media packed multistage-biofilm system for coke-plant wastewater treatment].

PubMed

Zhao, Wen-Tao; Huang, Xia; He, Miao; Zhang, Peng-Yi; Zuo, Chen-Yan

2009-02-15

The practical ammonia stripping effectiveness of coke-plant wastewater treatment may vary widely, and high NH4+-N shock loading will lead to the fluctuation of residual NH4+-N concentration of biological effluent. A zeolite media packed multistage-biofilm system (ZMBS) was used for coke-plant wastewater treatment for enhancing the NH4+-N treatment ability of the bio-system to shock loading, as well as achieving high COD removal efficiency. Treatment performance during steady-state and shock loading and transformation of organic pollutants in the system were investigated systematically. The experiment results indicated that when the system was operated at NH4+-N loading 0.21 kg/(m3 x d) and COD loading < or = 1.35 kg/(m3 x d), the average effluent NH4+-N and COD concentrations were (2.2 +/- 1.2) mg/L, (228 +/- 60) mg/L with average removal efficiencies of (99.1 +/- 0.5)% and (86.0 +/- 2.6)%. During the twice NH4+-N shock loadings [0.03 kg/(m3 x d) and 0.06 kg/(m3 x d)], ZMBS showed a strong resisting ability with average removal efficiencies of 99.0% and 92.9% higher than those of a compared system's 96.8% and 89.3%. By monitoring the change of water quality along the length of the ZMBS's cells, two function zones for different pollutant removal were found to exist, named as decarbonization/nitrification (C/N) zone and nitrification (N) zone, and the NH4+-N removal rate in N zone was 2-8 times as that in C/N zone. TOC concentrations of organic matters with relative molecular weight < 1 x 10(3), 1 x 10(3) to 1 x 10(4), and > 1 x 10(4), were 227.6, 104.8 and 35.0 mg/L in raw wastewater, and 31.2, 22.9 and 31.5 mg/L in the effluent, respectively. Organic matters with relative molecular weight < 1 x 10(3) and 1 x 10(3) to 1 x 10(4) in raw wastewater were removed effectively by ZMBS, but those with relative molecular weight > 1x 10(3) were the main remained substances in the effluent.

Dwarf Galaxies and the Cosmic Web

NASA Astrophysics Data System (ADS)

Benítez-Llambay, Alejandro; Navarro, Julio F.; Abadi, Mario G.; Gottlöber, Stefan; Yepes, Gustavo; Hoffman, Yehuda; Steinmetz, Matthias

2013-02-01

We use a cosmological simulation of the formation of the Local Group of Galaxies to identify a mechanism that enables the removal of baryons from low-mass halos without appealing to feedback or reionization. As the Local Group forms, matter bound to it develops a network of filaments and pancakes. This moving web of gas and dark matter drifts and sweeps a large volume, overtaking many halos in the process. The dark matter content of these halos is unaffected but their gas can be efficiently removed by ram pressure. The loss of gas is especially pronounced in low-mass halos due to their lower binding energy and has a dramatic effect on the star formation history of affected systems. This "cosmic web stripping" may help to explain the scarcity of dwarf galaxies compared with the numerous low-mass halos expected in ΛCDM and the large diversity of star formation histories and morphologies characteristic of faint galaxies. Although our results are based on a single high-resolution simulation, it is likely that the hydrodynamical interaction of dwarf galaxies with the cosmic web is a crucial ingredient so far missing from galaxy formation models.

Simultaneous removal of organic matter and salt ions from coal gasification wastewater RO concentrate and microorganisms succession in a MBR.

PubMed

Jia, Shengyong; Han, Yuxing; Zhuang, Haifeng; Han, Hongjun; Li, Kun

2017-10-01

A lab-scale membrane bioreactor (MBR) with intermittent aeration was operated to treat the reverse osmosis concentrate derived from coal gasification wastewater. Results showed intermittent aeration represented slight effect on organic matter reduction but significant effect on nitrite and nitrate reduction, with 6h aeration and 6h non-aeration, removal efficiencies of organic matter, chloride, sulfate, nitrite and nitrate reached 48.35%, 40.91%, 34.28%, -36.05% and 64.34%, respectively. High-throughput sequencing showed a microorganisms succession from inoculated activated sludge (S1) to activated sludge in MBR (S2) with high salinity. Richness and diversity of microorganisms in S2 was lower than S1 and the community structure of S1 exhibited more even than S2. The most relative abundance of genus in S1 and S2 were unclassified_Desulfarculaceae (9.39%) and Roseibaca (62.1%), respectively. High salinity and intermittent aeration represented different influence on the denitrifying genus, and non-aeration phase provided feasible dissolved oxygen condition for denitrifying genera realizing denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation of organic matter and anodic microbial communities analysis in sediment microbial fuel cells with/without Fe(III) oxide addition.

PubMed

Xu, Xun; Zhao, Qingliang; Wu, Mingsong; Ding, Jing; Zhang, Weixian

2017-02-01

To enhance the biodegradation of organic matter in sediment microbial fuel cell (SMFC), Fe(III) oxide, as an alternative electron acceptor, was added into the sediment. Results showed that the SMFC with Fe(III) oxide addition obtained higher removal efficiencies for organics than the SMFC without Fe(III) oxide addition and open circuit bioreactor, and produced a maximum power density (P max ) of 87.85mW/m 2 with a corresponding maximum voltage (V max ) of 0.664V. The alteration of UV-254 and specific ultraviolet absorbance (SUVA) also demonstrated the organic matter in sediments can be effectively removed. High-throughput sequencing of anodic microbial communities indicated that bacteria from the genus Geobacter were predominantly detected (21.23%) in the biofilm formed on the anode of SMFCs, while Pseudomonas was the most predominant genus (18.12%) in the presence of Fe(III) oxide. Additionally, compared with the open circuit bioreactor, more electrogenic bacteria attached to the biofilm of anode in SMFCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of natural organic matter on arsenic removal by modified granular natural siderite: Evidence of ternary complex formation by HPSEC-UV-ICP-MS.

PubMed

Li, Fulan; Guo, Huaming; Zhou, Xiaoqian; Zhao, Kai; Shen, Jiaxing; Liu, Fei; Wei, Chao

2017-02-01

High arsenic (As) groundwater usually has high concentrations of natural organic matter (NOM). Effects of NOM on arsenic adsorption were investigated to evaluate the efficiency of modified granular natural siderite (MGNS) as an adsorbent for groundwater arsenic remediation. Humic and fulvic acids (HA/FA) were selected as model NOM compounds. In batch tests, HA or FA was either first adsorbed onto the MGNS, or applied together with dissolved arsenic to investigate effects of both adsorbed and dissolved NOM on arsenic removal. The kinetic data showed no significant effects of both adsorbed and dissolved HA/FA on As(III) adsorption. However, As(V) removal was inhibited, whereby the adsorbed NOM compounds had greater inhibitory effect. The inhibitory effect on As(V) removal increased with increasing NOM concentrations. FA exhibited higher inhibitory effect than HA at the same concentration. Steric Exclusion Chromatography-HPLC (SEC-HPLC), and High-Performance Size Exclusion Chromatography-UV-Inductively Coupled Plasma Mass Spectrometry (HPSEC-UV-ICP-MS) revealed that As(V) removal was mostly achieved by the oxyanion adsorption and adversely affected by dissolved FA via competitive adsorption for surface sites. In addition to oxyanion adsorption, removal of As(V) was related to scavenging of ternary HA-As-Fe complexes, which led to the less inhibitory effect of dissolved HA on As(V) removal than dissolved FA via competitive adsorption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of different temperatures on performance and membrane fouling in high concentration PAC-MBR system treating micro-polluted surface water.

PubMed

Ma, Cong; Yu, Shuili; Shi, Wenxin; Heijman, S G J; Rietveld, L C

2013-08-01

A bench-scale immersed microfiltration coupled with 50 g/L PAC was developed to treat micro-polluted surface water (MPSW) under 10 and 20 °C and the effects of temperatures on the performance and the membrane fouling were also investigated. The low temperature (10 °C) delayed the time for the start-up by 9 days and the complete nitrification by 10 days. In the stable operation, two systems both had high NH₃-N removal efficiency (above 90%) and better removal of organic matters (10% DOC, 5% UV₂₅₄ and 4% SUVA) at 10 °C. Polysaccharides (SMP) were the main membrane fouling matters at low temperature (10 °C) and low temperature (10 °C) didn't cause serious chemical irreversible membrane fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dispersion of C(60) in natural water and removal by conventional drinking water treatment processes.

PubMed

Hyung, Hoon; Kim, Jae-Hong

2009-05-01

The first objective of this study is to examine the fate of C(60) under two disposal scenarios through which pristine C(60) is introduced to water containing natural organic matter (NOM). A method based on liquid-liquid extraction and HPLC to quantify nC(60) in water containing NOM was also developed. When pristine C(60) was added to water either in the form of dry C(60) or in organic solvent, it formed water stable aggregates with characteristics similar to nC(60) prepared by other methods reported in the literature. The second objective of this study is to examine the fate of the nC(60) in water treatment processes, which are the first line of defense against ingestion from potable water -- a potential route for direct human consumption. Results obtained from jar tests suggested that these colloidal aggregates of C(60) were efficiently removed by a series of alum coagulation, flocculation, sedimentation and filtration processes, while the efficiency of removal dependent on various parameters such as pH, alkalinity, NOM contents and coagulant dosage. Colloidal aggregates of functionalized C(60) could be well removed by the conventional water treatment processes but with lesser efficiency compared to those made of pristine C(60).

40 CFR 63.4362 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., carbon dioxide, and carbon monoxide content of exhaust gas in ANSI/ASME, PTC 19.10-1981, “Flue and Exhaust Gas Analyses [Part 10, Instruments and Apparatus]” (incorporated by reference, see § 63.14). (4... applicable, during each test run. (b) Measure the volatile organic matter concentration as carbon at the...

Explaining the apparent resiliency of loblolly pine plantation to organic matter removal

Treesearch

Jeff A. Hatten; Eric B. Surce; Zakiya Leggett; Jason Mack; Scott D. Roberts; Janet Dewey; Brian Strahm

2015-01-01

We utilized 15-year measurements from an organic matter manipulation experiment in a loblolly pine plantation in the Upper Coastal Plain of Alabama to examine the apparent resiliency of a loblolly pine stand to organic matter removal. Treatments included complete removal of harvest residues and forest floor (removed), doubling of harvest residues and forest floor (...

Variations of floc morphology and extracellular organic matters (EOM) in relation to floc filterability under algae flocculation harvesting using polymeric titanium coagulants (PTCs).

PubMed

Zhang, Weijun; Song, Rongna; Cao, Bingdi; Yang, Xiaofang; Wang, Dongsheng; Fu, Xingmin; Song, Yao

2018-05-01

The work evaluated the algae cells removal efficiency using titanium salt coagulants with different degree of polymerization (PTCs), and the algae cells aggregates and extracellular organic matter (EOM) under chemical flocculation were investigated. The results indicated that PTCs performed well in algae cells flocculation and separation. The main mechanism using PTCs of low alkalisation degree for algae flocculation was associated with charge neutralization, while adsorption bridging and sweep flocculation was mainly responsible for algae removal by PTCs of high alkalisation degree treatment. In addition, the flocs formed by PTC 1.0 showed the best filtration property, and EOM reached the minimum at this time, indicating the flocs formed by PTC 1.0 were more compact than other PTCs, which can be confirmed by SEM analysis. Three-dimensional excitation emission matrix fluorescence (3D-EEM) and high performance size exclusion chromatography (HPSEC) revealed that the EOMs were removed under PTCs flocculation, which improved floc filterability. Copyright © 2018 Elsevier Ltd. All rights reserved.

Removal of less biodegradable dissolved organic matters in water by superconducting magnetic separation with magnetic mesoporous carbon

NASA Astrophysics Data System (ADS)

Kondo, K.; Jin, T.; Miura, O.

2010-11-01

Less biodegradable dissolved organic matters in water as typified by humic substances are known as precursors of carcinogenic trihalomethanes, and are removed about 60% by current advanced water treatments. However, further increase of the removal ratio is demand. In this study, magnetic mesoporous carbon (MMPC), which can adsorb the substances physically and be efficiently collected by using superconducting high gradient magnetic separation (HGMS), has been synthesized with coconut-shell-based activated carbon and ferric nitrate solution by the gas activation method. The MMPC has the maximum magnetization value of 30.7 emu/g and an adsorption ability of 87% to 10 mg/L humic acid in a short time. The standard MMPC having a magnetization of 6.43 emu/g was able to be separated at magnetic field of 2 T. Used MMPC regained the adsorption ability to 93.1% by N2 reactivation heat treatment. These results show promise for application of current water treatments by superconducting HGMS, which is suitable for high-speed water treatment without secondary wastes.

Using fluorescence-parallel factor analysis for assessing disinfection by-product formation and natural organic matter removal efficiency in secondary treated synthetic drinking waters.

PubMed

Watson, Kalinda; Farré, Maria José; Leusch, Frederic D L; Knight, Nicole

2018-05-28

Parallel factor (PARAFAC) analysis of fluorescence excitation-emission matrices (EEMs) was used to investigate the organic matter and DBP formation characteristics of untreated, primary treated (enhanced coagulation; EC) and secondary treated synthetic waters prepared using a Suwannee River natural organic matter (SR-NOM) isolate. The organic matter was characterised by four different fluorescence components; two humic acid-like (C1 and C2) and two protein-like (C3 and C4). Secondary treatment methods tested, following EC treatment, were; powdered activated carbon (PAC), granular activated carbon (GAC), 0.1% silver-impregnated activated carbon (SIAC), and MIEX® resin. Secondary treatments were more effective at removing natural organic matter (NOM) and fluorescent DBP-precursor components than EC alone. The formation of a suite of 17 DBPs including chlorinated, brominated and iodinated trihalomethanes (THMs), dihaloacetonitriles (DHANs), chloropropanones (CPs), chloral hydrate (CH) and trichloronitromethane (TCNM) was determined after chlorinating water sampled before and after each treatment step. Regression analysis was used to investigate the relationship between peak component fluorescence intensity (F MAX ), DBP concentration and speciation, and more commonly used aggregate parameters such as DOC, UV 254 and SUVA 254 . PARAFAC component 1 (C1) was in general a better predictor of DBP formation than other aggregate parameters, and was well correlated (R ≥ 0.80) with all detected DBPs except dibromochloromethane (DBCM) and dibromoacetonitrile (DBAN). These results indicate that the fluorescence-PARAFAC approach could provide a robust analytical tool for predicting DBP formation, and for evaluating the removal of NOM fractions relevant to DBP formation during water treatment. Copyright © 2018. Published by Elsevier B.V.

Removal of long-lived 222Rn daughters by electropolishing thin layers of stainless steel

NASA Astrophysics Data System (ADS)

Schnee, R. W.; Bowles, M. A.; Bunker, R.; McCabe, K.; White, J.; Cushman, P.; Pepin, M.; Guiseppe, V. E.

2013-08-01

Long-lived alpha and beta emitters in the 222Rn decay chain on detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. Removal of tens of microns of material via electropolishing has been shown to be effective at removing radon daughters implanted into material surfaces. Some applications, however, require the removal of uniform and significantly smaller thicknesses. Here, we demonstrate that electropolishing < 1 μm from stainless-steel plates reduces the contamination efficiently, by a factor > 100. Examination of electropolished wires with a scanning electron microscope confirms that the thickness removed is reproducible and reasonably uniform. Together, these tests demonstrate the effectiveness of removal of radon daughters for a proposed low-radiation, multi-wire proportional chamber (the BetaCage), without compromising the screener's energy resolution. More generally, electropolishing thin layers of stainless steel may effectively remove radon daughters without compromising precision-machined parts.

Removal of long-lived {sup 222}Rn daughters by electropolishing thin layers of stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schnee, R. W.; Bowles, M. A.; Bunker, R.

Long-lived alpha and beta emitters in the {sup 222}Rn decay chain on detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. Removal of tens of microns of material via electropolishing has been shown to be effective at removing radon daughters implanted into material surfaces. Some applications, however, require the removal of uniform and significantly smaller thicknesses. Here, we demonstrate that electropolishing < 1 μm from stainless-steel plates reduces the contamination efficiently, by a factor > 100. Examination of electropolished wires with a scanning electron microscope confirms that the thicknessmore » removed is reproducible and reasonably uniform. Together, these tests demonstrate the effectiveness of removal of radon daughters for a proposed low-radiation, multi-wire proportional chamber (the BetaCage), without compromising the screener’s energy resolution. More generally, electropolishing thin layers of stainless steel may effectively remove radon daughters without compromising precision-machined parts.« less

Development of a novel proton exchange membrane-free integrated MFC system with electric membrane bioreactor and air contact oxidation bed for efficient and energy-saving wastewater treatment.

PubMed

Gao, Changfei; Liu, Lifen; Yang, Fenglin

2017-08-01

A novel combined system integrating MFC and electric membrane bioreactor (EMBR) was developed, in which a quartz sand chamber (QSC) was used, replacing expensive proton exchange membrane (PEM). An air contact oxidation bed (ACOB) and embedded trickling filter (TF) with filled volcano rock, was designed to increase dissolved oxygen (DO) in cathodic EMBR to save aeration cost. Membrane fouling in EMBR was successful inhibited/reduced by the generated bioelectricity of the system. The combined system demonstrated superior effluent quality in removing chemical oxygen demand (>97%) and ammonia nitrogen (>93%) during the stable operation, and the phosphorus removal was about 50%. Dominant bacteria (Nitrosomonas sp.; Comamonas sp.; Candidatus Kuenenia) played important roles in the removal of organic matter and ammonia nitrogen. The system has good application prospects in the efficient use of water and the development of sustainable wastewater recycling technology. Copyright © 2017. Published by Elsevier Ltd.

The impact of loading approach and biological activity on NOM removal by ion exchange resins.

PubMed

Winter, Joerg; Wray, Heather E; Schulz, Martin; Vortisch, Roman; Barbeau, Benoit; Bérubé, Pierre R

2018-05-01

The present study investigated the impact of different loading approaches and microbial activity on the Natural Organic Matter (NOM) removal efficiency and capacity of ion exchange resins. Gaining further knowledge on the impact of loading approaches is of relevance because laboratory-scale multiple loading tests (MLTs) have been introduced as a simpler and faster alternative to column tests for predicting the performance of IEX, but only anecdotal evidence exists to support their ability to forecast contaminant removal and runtime until breakthrough of IEX systems. The overall trends observed for the removal and the time to breakthrough of organic material estimated using MLTs differed from those estimated using column tests. The results nonetheless suggest that MLTs could best be used as an effective tool to screen different ion exchange resins in terms of their ability to remove various contaminants of interest from different raw waters. The microbial activity was also observed to impact the removal and time to breakthrough. In the absence of regeneration, a microbial community rapidly established itself in ion exchange columns and contributed to the removal of organic material. Biological ion exchange (BIEX) removed more organic material and enabled operation beyond the point when the resin capacity would have otherwise been exhausted using conventional (i.e. in the absence of a microbial community) ion exchange. Furthermore, significantly greater removal of organic matter could be achieved with BIEX than biological activated carbon (BAC) (i.e. 56 ± 7% vs. 15 ± 5%, respectively) when operated at similar loading rates. The results suggest that for some raw waters, BIEX could replace BAC as the technology of choice for the removal of organic material. Copyright © 2018 Elsevier Ltd. All rights reserved.

An investigation of the leaf retention capacity, efficiency and mechanism for atmospheric particulate matter of five greening tree species in Beijing, China.

PubMed

Liu, Jinqiang; Cao, Zhiguo; Zou, Songyan; Liu, Huanhuan; Hai, Xiao; Wang, Shihua; Duan, Jie; Xi, Benye; Yan, Guangxuan; Zhang, Shaowei; Jia, Zhongkui

2018-03-01

Urban trees have the potential to reduce air pollution, but the retention capacity and efficiency of different tree species for atmospheric particulate matter (PM) accumulation and the underlying mechanism hasn't been well understood. To select tree species with high air purification abilities, the supplementing ultrasonic cleaning (UC) procedure was first introduced into the conventional leaf cleaning methods [single water cleaning (WC) or plus brush cleaning (BC)] for eluting the leaf-retained PM. Further updates to the methodology were applied to investigate the retention capacity, efficiency, and mechanism for PM of five typical greening tree species in Beijing, China. Meanwhile, the particle size distribution of PM on the leaves, the PM retention efficiencies of easily removable (ERP), difficult-to-remove (DRP) and totally removable (TRP) particles on the leaf (AE leaf ), and the individual tree scales were estimated. The experimental leaf samples were collected from trees with similar sizes 4 (SDR) and 14days (LDR) after rainfall. When the leaves were cleaned by WC+BC, there was, on average, 29%-46% of the PM remaining on the leaves of different species, which could be removed almost completely if UC was supplemented. From SDR to LDR, the mass of the leaf-retained PM increased greatly, and the particle size distribution changed markedly for all species except for Sophorajaponica. Pinus tabuliformis retains particles with the largest average diameter (34.2μm), followed by Ginkgo biloba (20.5μm), Sabina chinensis (16.4μm), Salix babylonica (16.0μm), and S. japonica (13.1μm). S. japonica and S. chinensis had the highest AE leaf to retain the TRP and ERP of both PM 1 and PM 1-2.5 , respectively. Conversely, S. babylonica and P. tabuliformis could retain both TRP and ERP of PM 2.5-5 and PM 5-10 , and PM >10 and TSP with the highest AE leaf , respectively. In conclusion, our results could be useful in selecting greening tree species with high air purification abilities. Copyright © 2017 Elsevier B.V. All rights reserved.

Shifts of system performance and microbial community structure in a constructed wetland after exposing silver nanoparticles.

PubMed

Cao, Chong; Huang, Juan; Yan, Chunni; Liu, Jialiang; Hu, Qian; Guan, Wenzhu

2018-05-01

The increasing utilization of silver nanoparticles (Ag NPs) in industry and commerce inevitably raises its release into wastewater. In this work, effects of Ag NPs on system performance and microbial community along the way of a vertical flow constructed wetland (VFCW) were investigated, along with the removal and fate of Ag NPs within the system. Results showed that the performance of control wetland kept stable during the experimental period, and the top substrate layer (soil layer) of wetland could remove most of pollutants in the influent. The study also suggested that addition of Ag NPs did not significantly affect organic matters removal. However, adverse effects were observed on the nitrogen and phosphorus removal. Removal efficiencies of TN, NH 4 + -N and TP approximately obviously reduced by approximately 10.10%, 8.42% and 28.35% respectively in contrast to before dosing after exposing 100 μg/L Ag NPs for 94 d, while the no dosing wetland with the stable performance. It was found that Ag NPs accumulated in the upper soil layer more than in the lower soil layer, and Ag NPs could enter into the plant tissues. After continuous input of Ag NPs, removal efficiency of Ag NPs was measured as 95.72%, which showed that the CW could effectively remove Ag NPs from the wastewater. The high-throughput sequencing results revealed that Ag NPs caused the shifts in microbial community structures and changed the relative abundances of key functional bacteria, which finally resulted in a lower efficiency of biological nitrogen and phosphorus removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Novel insights into anoxic/aerobic(1)/aerobic(2) biological fluidized-bed system for coke wastewater treatment by fluorescence excitation-emission matrix spectra coupled with parallel factor analysis.

PubMed

Ou, Hua-Se; Wei, Chao-Hai; Mo, Ce-Hui; Wu, Hai-Zhen; Ren, Yuan; Feng, Chun-Hua

2014-10-01

Fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) was applied to investigate the contaminant removal efficiency and fluorescent characteristic variations in a full scale coke wastewater (CWW) treatment plant with a novel anoxic/aerobic(1)/aerobic(2) (A/O(1)/O(2)) process, which combined with internal-loop fluidized-bed reactor. Routine monitoring results indicated that primary contaminants in CWW, such as phenols and free cyanide, were removed efficiently in A/O(1)/O(2) process (removal efficiency reached 99% and 95%, respectively). Three-dimensional excitation-emission matrix fluorescence spectroscopy and PARAFAC identified three fluorescent components, including two humic-like fluorescence components (C1 and C3) and one protein-like component (C2). Principal component analysis revealed that C1 and C2 correlated with COD (correlation coefficient (r)=0.782, p<0.01 and r=0.921, p<0.01), respectively) and phenols (r=0.796, p<0.01 and r=0.914, p<0.01, respectively), suggesting that C1 and C2 might be associated with the predominating aromatic contaminants in CWW. C3 correlated with mixed liquor suspended solids (r=0.863, p<0.01) in fluidized-bed reactors, suggesting that it might represent the biological dissolved organic matter. In A/O(1)/O(2) process, the fluorescence intensities of C1 and C2 consecutively decreased, indicating the degradation of aromatic contaminants. Correspondingly, the fluorescence intensity of C3 increased in aerobic(1) stage, suggesting an increase of biological dissolved organic matter. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removing organic matter from sulfate-rich wastewater via sulfidogenic and methanogenic pathways.

PubMed

Vilela, Rogerio Silveira; Damianovic, Márcia Helena Rissato Zamariolli; Foresti, Eugenio

2014-01-01

The simultaneous organic matter removal and sulfate reduction in synthetic sulfate-rich wastewater was evaluated for various chemical oxygen demand (COD)/sulfate ratios applied in a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. At higher COD/sulfate ratios (12.5 and 7.5), the removal of organic matter was stable, likely due to methanogenesis. A combination of sulfate reduction and methanogenesis was clearly established at COD/sulfate ratios of 3.0 and 1.9. At a COD/sulfate ratio of 1.0, the organic matter removal was likely influenced by methanogenesis inhibition. The quantity of sulfate removed at a COD/sulfate ratio of 1.0 was identical to that obtained at a ratio of 1.9, indicating a lack of available electron donors for sulfidogenesis. The sulfate reduction and organic matter removal were not maximized at the same COD/sulfate ratio; therefore, competitive inhibition must be the predominant mechanism in establishing an electron flow.

Evaluation of the simultaneous removal of recalcitrant drugs (bezafibrate, gemfibrozil, indomethacin and sulfamethoxazole) and biodegradable organic matter from synthetic wastewater by electro-oxidation coupled with a biological system.

PubMed

Rodríguez-Nava, Odín; Ramírez-Saad, Hugo; Loera, Octavio; González, Ignacio

2016-12-01

Pharmaceutical degradation in conventional wastewater treatment plants (WWTP) represents a challenge since municipal wastewater and hospital effluents contain pharmaceuticals in low concentrations (recalcitrant and persistent in WWTP) and biodegradable organic matter (BOM) is the main pollutant. This work shows the feasibility of coupling electro-oxidation with a biological system for the simultaneous removal of recalcitrant drugs (bezafibrate, gemfibrozil, indomethacin and sulfamethoxazole (BGIS)) and BOM from wastewater. High removal efficiencies were attained without affecting the performance of activated sludge. BGIS degradation was performed by advanced electrochemical oxidation and the activated sludge process for BOM degradation in a continuous reactor. The selected electrochemical parameters from microelectrolysis tests (1.2 L s(-1) and 1.56 mA cm(-2)) were maintained to operate a filter press laboratory reactor FM01-LC using boron-doped diamond as the anode. The low current density was chosen in order to remove drugs without decreasing BOM and chlorine concentration control, so as to avoid bulking formation in the biological process. The wastewater previously treated by FM01-LC was fed directly (without chemical modification) to the activated sludge reactor to remove 100% of BGIS and 83% of BOM; conversely, the BGIS contained in wastewater without electrochemical pre-treatment were persistent in the biological process and promoted bulking formation.

Do constructed wetlands remove metals or increase metal bioavailability?

PubMed

Xu, Xiaoyu; Mills, Gary L

2018-07-15

The H-02 wetland was constructed to treat building process water and storm runoff water from the Tritium Processing Facility on the Department of Energy's Savannah River Site (Aiken, SC). Monthly monitoring of copper (Cu) and zinc (Zn) concentrations and water quality parameters in surface waters continued from 2014 to 2016. Metal speciation was modeled at each sampling occasion. Total Cu and Zn concentrations released to the effluent stream were below the NPDES limit, and the average removal efficiency was 65.9% for Cu and 71.1% for Zn. The metal-removal processes were found out to be seasonally regulated by sulfur cycling indicated by laboratory and model results. High temperature, adequate labile organic matter, and anaerobic conditions during the warm months (February to August) favored sulfate reduction that produced sulfide minerals to significantly remove metals. However, the dominant reaction in sulfur cycling shifted to sulfide oxidation during the cool months (September to next March). High concentrations of metal-organic complexes were observed, especially colloidal complexes of metal and fulvic acid (FA), demonstrating adsorption to organic matter became the primary process for metal removal. Meanwhile, the accumulation of metal-FA complexes in the wetland system will cause negative effects to the surrounding environment as they are biologically reactive, highly bioavailable, and can be easily taken up and transferred to ecosystems by trophic exchange. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes.

PubMed

Zayas Pérez, Teresa; Geissler, Gunther; Hernandez, Fernando

2007-01-01

The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculation and advanced oxidation processes (AOP) had been studied. The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H2O2, UV/O3 and UV/H2O2/O3 processes was determined under acidic conditions. For each of these processes, different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater. Coffee wastewater is characterized by a high chemical oxygen demand (COD) and low total suspended solids. The outcomes of coffee wastewater treatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD, color, and turbidity. It was found that a reduction in COD of 67% could be realized when the coffee wastewater was treated by chemical coagulation-flocculation with lime and coagulant T-1. When coffee wastewater was treated by coagulation-flocculation in combination with UV/H2O2, a COD reduction of 86% was achieved, although only after prolonged UV irradiation. Of the three advanced oxidation processes considered, UV/H2O2, UV/O3 and UV/H2O2/O3, we found that the treatment with UV/H2O2/O3 was the most effective, with an efficiency of color, turbidity and further COD removal of 87%, when applied to the flocculated coffee wastewater.

Treatment of table olive washing water using trickling filters, constructed wetlands and electrooxidation.

PubMed

Tatoulis, Triantafyllos; Stefanakis, Alexandros; Frontistis, Zacharias; Akratos, Christos S; Tekerlekopoulou, Athanasia G; Mantzavinos, Dionissios; Vayenas, Dimitrios V

2017-01-01

The production of table olives is a significant economic activity in Mediterranean countries. Table olive processing generates large volumes of rinsing water that are characterized by high organic matter and phenol contents. Due to these characteristics, a combination of more than one technology is imperative to ensure efficient treatment with low operational cost. Previously, biological filters were combined with electrooxidation to treat table olive washing water. Although this combination was successful in reducing pollutant loads, its cost could be further reduced. Constructed wetlands could be an eligible treatment method for integrated table olive washing water treatment as they have proved tolerant to high organic matter and phenol loads. Two pilot-scale horizontal subsurface constructed wetlands, one planted and one unplanted, were combined with a biological filter and electrooxidation over a boron-doped diamond anode to treat table olive washing water. In the biological filter inlet, chemical oxygen demand (COD) concentrations ranged from 5500 to 15,000 mg/L, while mean COD influent concentration in the constructed wetlands was 2800 mg/L. The wetlands proved to be an efficient intermediate treatment stage, since COD removal levels for the planted unit reached 99 % (mean 70 %), while the unplanted unit presented removal rates of around 65 %. Moreover, the concentration of phenols in the effluent was typically below 100 mg/L. The integrated trickling filter-constructed wetland-electrooxidation treatment system examined here could mineralize and decolorize table olive washing water and fully remove its phenolic content.

Defluoridation of water using activated alumina in presence of natural organic matter via response surface methodology.

PubMed

Samarghandi, Mohammad Reza; Khiadani, Mehdi; Foroughi, Maryam; Zolghadr Nasab, Hasan

2016-01-01

Adsorption by activated alumina is considered to be one of the most practiced methods for defluoridation of freshwater. This study was conducted, therefore, to investigate the effect of natural organic matters (NOMs) on the removal of fluoride by activated alumina using response surface methodology. To the authors' knowledge, this has not been previously investigated. Physico-chemical characterization of the alumina was determined by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and X-ray diffractometer (XRD). Response surface methodology (RSM) was applied to evaluate the effect of single and combined parameters on the independent variables such as the initial concentration of fluoride, NOMs, and pH on the process. The results revealed that while presence of NOM and increase of pH enhance fluoride adsorption on the activated alumina, initial concentration of fluoride has an adverse effect on the efficiency. The experimental data were analyzed and found to be accurately and reliably fitted to a second-order polynomial model. Under optimum removal condition (fluoride concentration 20 mg/L, NOM concentration 20 mg/L, and pH 7) with a desirability value of 0.93 and fluoride removal efficiency of 80.6%, no significant difference was noticed with the previously reported sequence of the co-exiting ion affinity to activated alumina for fluoride removal. Moreover, aluminum residual was found to be below the recommended value by the guideline for drinking water. Also, the increase of fluoride adsorption on the activated alumina, as NOM concentrations increase, could be due to the complexation between fluoride and adsorbed NOM. Graphical abstract ᅟ.

An experimental model of COD abatement in MBBR based on biofilm growth dynamic and on substrates' removal kinetics.

PubMed

Siciliano, Alessio; De Rosa, Salvatore

2016-08-01

In this study, the performance of a lab-scale Moving Bed Biofilm Reactor (MBBR) under different operating conditions was analysed. Moreover, the dependence of the reaction rates both from the concentration and biodegradability of substrates and from the biofilm surface density, by means of several batch kinetic tests, was investigated. The reactor controls exhibited an increasing COD (Chemical Oxygen Demand) removal, reaching maximum yields (close to 90%) for influent loadings of up to12.5 gCOD/m(2)d. From this value, the pilot plant performance decreased to yields of only about 55% for influent loadings greater than 16 gCOD/m(2)d. In response to the influent loading increase, the biofilm surface density exhibited a logistic growing trend until reaching a maximum amount of total attached solids of about 9.5 g/m(2). The kinetic test results indicated that the COD removal rates for rapidly biodegradable, rapidly hydrolysable and slowly biodegradable substrates were not affected by the organic matter concentrations. Instead, first-order kinetics were detected with respect to biofilm surface density. The experimental results permitted the formulation of a mathematical model to predict the MBBR organic matter removal efficiency. The validity of the model was successfully tested in the lab-scale plant.

Picosecond laser micromachining prior to FIB milling for electronic microscopy sample preparation

NASA Astrophysics Data System (ADS)

Sikora, Aurélien; Fares, Lahouari; Adrian, Jérôme; Goubier, Vincent; Delobbe, Anne; Corbin, Antoine; Sentis, Marc; Sarnet, Thierry

2017-10-01

In order to check the manufacturing quality of electronic components using electron microscopy, the area of interest must be exposed. This requires the removal of a large quantity of matter without damaging the surrounding area. This step can be accomplished using ion milling but the processing can last a few hours. In order to accelerate the preparation of the samples, picosecond laser micromachining prior to Focused Ion Beam polishing is envisioned. Laser ablation allows the fast removal of matter but induces damages around the ablated area. Therefore the process has to be optimized in order to limit the size of both the heat affected zone and induced dislocation zone. For this purpose, cavities have been engraved in silicon and in electronic components, using a linearly polarized picosecond laser (∼50 ps) at three different wavelengths (343, 515 and 1030 nm). Results showed that the cross sectional shapes and the surface topologies can be tuned by the laser fluence and the number of pulses. Clear cross sections of bumps and cavity openings, exposing multilayer interfaces, are demonstrated. The silicon removal rates, tuned by the applied energy density, have been measured. Removal rates achieved at 200 kHz were typically hundred times higher than those achieved by ion milling and the best efficiency was obtained at 343 nm.

Profiles and removal efficiency of polycyclic aromatic hydrocarbons by two different types of sewage treatment plants in Hong Kong.

PubMed

Man, Yu Bon; Chow, Ka Lai; Cheng, Zhang; Mo, Wing Yin; Chan, Yung Hau; Lam, James Chung Wah; Lau, Frankie Tat Kwong; Fung, Wing Cheong; Wong, Ming Hung

2017-03-01

Sewage discharge could be a major source of polycyclic aromatic hydrocarbons (PAHs) in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works (SCISTW and STSTW) in Hong Kong, adopted chemically enhanced primary treatment and biological treatment, respectively. This study aimed at (1) determining the removal efficiencies of PAHs, (2) comparing the capabilities in removing PAHs, and (3) characterizing the profile of each individual PAHs, in the two sewage treatment plants (STPs). Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes (from 301±255 and 307±217ng/L to 14.9±12.1 and 63.3±54.1ng/L in STSTW and SCISTW, respectively). It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal efficiency 94.4%±4.12% vs. 79.2%±7.48% (p<0.05). The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples (dewatered sludge contained 92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively) than liquid samples (final effluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively). Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs (1.85 and 39.3kg/year, respectively for the two STPs) being discharged into Hong Kong coastal waters, which would be an environmental concern. Copyright © 2016. Published by Elsevier B.V.

Treatment of soft drink process wastewater by ozonation, ozonation-H₂O₂ and ozonation-coagulation processes.

PubMed

García-Morales, M A; Roa-Morales, G; Barrera-Díaz, C; Balderas-Hernández, P

2012-01-01

In this research, we studied the treatment of wastewater from the soft drink process using oxidation with ozone. A scheme composed of sequential ozonation-peroxide, ozonation-coagulation and coagulation-ozonation treatments to reduce the organic matter from the soft drink process was also used. The samples were taken from the conventional activated sludge treatment of the soft drink process, and the experiments using chemical oxidation with ozone were performed in a laboratory using a reactor through a porous plate glass diffuser with air as a feedstock for the generation of ozone. Once the sample was ozonated, the treatments were evaluated by considering the contact time, leading to greater efficiency in removing colour, turbidity and chemical oxygen demand (COD). The effect of ozonation and coagulant coupled with treatment efficiency was assessed under optimal conditions, and substantial colour and turbidity removal were found (90.52% and 93.33%, respectively). This was accompanied by a 16.78% reduction in COD (initial COD was 3410 mg/L). The absorbance spectra of the oxidised products were compared using UV-VIS spectroscopy to indicate the level of oxidation of the wastewater. We also determined the kinetics of decolouration and the removal of turbidity with the best treatment. The same treatment was applied to the sample taken from the final effluent of the activated sludge system, and a COD removal efficiency of 100% during the first minute of the reaction with ozone was achieved. As a general conclusion, we believe that the coagulant polyaluminum chloride - ozone (PAC- ozone) treatment of wastewater from the manufacturing of soft drinks is the most efficient for removing turbidity and colour and represents an advantageous option to remove these contaminants because their removal was performed in minutes compared to the duration of traditional physical, chemical and biological processes that require hours or days.

Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor

PubMed Central

Talebizadeh, Pouyan; Rahimzadeh, Hassan; Babaie, Meisam; Javadi Anaghizi, Saeed; Ghomi, Hamidreza; Ahmadi, Goodarz; Brown, Richard

2015-01-01

Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode. PMID:26496630

Performance evaluation of a large sewage treatment plant in Brazil, consisting of an upflow anaerobic sludge blanket reactor followed by activated sludge.

PubMed

Saliba, Pollyane Diniz; von Sperling, Marcos

2017-10-01

The objective of this study was to evaluate the behaviour of a system comprising an upflow anaerobic sludge blanket reactor followed by activated sludge to treat domestic sewage. The Betim Central sewage treatment plant, Brazil, was designed to treat a mean influent flow of 514 L/s. The study consisted of statistical treatment of monitoring data from the treatment plant covering a period of 4 years. This work presents the concentrations and removal efficiencies of the main constituents in each stage of the treatment process, and a mass balance of chemical oxygen demand (COD) and nitrogen. The results highlight the good overall performance of the system, with high mean removal efficiencies: BOD (biochemical oxygen demand) (94%), COD (91%), ammonia (72%) and total suspended solids (92%). As expected, this system was not effective for the removal of nutrients, since it was not designed for this purpose. The removal of Escherichia coli (99.83%) was higher than expected. There was no apparent influence of operational and design parameters on the effluent quality in terms of organic matter removal, with the exceptions of the BOD load upstream of the aeration tank and the sludge age in the unit. Results suggest that this system is well suited for the treatment of domestic sewage.

Effect of organic matter on cyanide removal by illuminated titanium dioxide or zinc oxide nanoparticles

PubMed Central

2013-01-01

Effect of different type of organic compounds (humic acid, oxalate, ethylenediaminetetraacetic acid, nitrilotriacetic acid, phenol) on the photocatalytic removal of cyanide with TiO2 or ZnO was studied in this work with variation of the solution pH, contact time, initial cyanide concentration and type of organic compounds. Photocatalytic oxidation efficiency of cyanide with TiO2 was greatly affected by the solution pH. It increased as the solution pH decreased. Also maximum removal of cyanide by ZnO was observed near at neutral pH because of the reduced photocatalytic activity of ZnO at exceedingly low and high pH values originated from either acidic/photochemical corrosion of the catalyst and/or surface passivation with Zn(OH)2. Removal efficiency of cyanide greatly decreased in the presence of humic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid compared to that without presence of organic compound because of the competitive oxidation as well as surface blocking by relatively large organic compounds. The oxidation pattern of cyanide was better described by first-order kinetic model. Finally photocatalytic reaction with TiO2 or ZnO can be effectively applied to treat synthetic wastewater contaminated with cyanide. PMID:24499704

Performance evaluation and microbial community analysis of the function and fate of ammonia in a sulfate-reducing EGSB reactor.

PubMed

Wang, Depeng; Liu, Bo; Ding, Xinchun; Sun, Xinbo; Liang, Zi; Sheng, Shixiong; Du, Lingfeng

2017-10-01

Ammonia is widely distributed in sulfate-reducing bioreactor dealing with sulfate wastewater, which shows potential effect on the metabolic pathway of sulfate and ammonia. This study investigates the sulfate-reducing efficiency and microbial community composition in the sulfate-reducing EGSB reactor with the increasing ammonia loading. Results indicated that, compared with low ammonia loading (166-666 mg/L), the sulfate and organic matter removal efficiencies were improved gradually with the appropriate ammonia loading (1000-2000 mg/L), which increased from 63.58 ± 3.81 to 71.08 ± 1.36% and from 66.24 ± 1.32 to 81.88 ± 1.83%, respectively. Meanwhile, with the appropriate ratio of ammonia and sulfate (1.5-3.0) and hydraulic retention time (21 h), the sulfate-reducing anaerobic ammonia oxidation (SRAO) process was occurred efficiently, inducing the accumulation of S 0 (270 mg/L) and the simultaneous ammonia removal (70.83%) in EGSB reactor. Moreover, the key sulfate-reducing bacteria (SRB) (Desulfovibrio) and denitrification bacteria (Pseudomonas and Alcaligenes) were responsible for the sulfate and nitrogen removal in these phases, which accounted for 3.66-5.54 and 3.85-9.13%, respectively. However, as the ammonia loading higher than 3000 mg/L (phases 9 and 10), the sulfate-reducing efficiency was decreased to only 28.3 ± 1.26% with the ammonia removal rate of 18.4 ± 3.37% in the EGSB reactor. Meanwhile, the predominant SRB in phases 9 and 10 were Desulfomicrobium (1.22-1.99%) and Desulfocurvus (4.0-5.46%), and the denitrification bacteria accounted for only 0.88% (phase 10), indicating the low nitrogen removal rate.

Harmful algal bloom removal and eutrophic water remediation by commercial nontoxic polyamine-co-polymeric ferric sulfate-modified soils.

PubMed

Dai, Guofei; Zhong, Jiayou; Song, Lirong; Guo, Chunjing; Gan, Nanqin; Wu, Zhenbin

2015-07-01

Harmful algal bloom has posed great threat to drinking water safety worldwide. In this study, soils were combined with commercial nontoxic polyamine poly(epichlorohydrin-dimethylamine) (PN) and polymeric ferric sulfate (PFS) to obtain PN-PFS soils for Microcystis removal and eutrophic water remediation under static laboratory conditions. High pH and temperature in water could enhance the function of PN-PFS soil. Algal removal efficiency increased as soil particle size decreased or modified soil dose increased. Other pollutants or chemicals (such as C, P, and organic matter) in eutrophic water could participate and promote algal removal by PN-PFS soil; these pollutants were also flocculated. During PN-PFS soil application in blooming field samples, the removal efficiency of blooming Microcystis cells exceeded 99 %, the cyanotoxin microcystins reduced by 57 %. Water parameters (as TP, TN, SS, and SPC) decreased by about 90 %. CODMn, PO4-P, and NH4-N also sharply decreased by >45 %. DO and ORP in water improved. Netting and bridging effects through electrostatic attraction and complexation reaction could be the two key mechanisms of Microcystis flocculation and pollutant purification. Considering the low cost of PN-PFS soil and its nontoxic effect on the environment, we proposed that this soil combination could be applied to remove cyanobacterial bloom and remediate eutrophic water in fields.

Classes of organic molecules targeted by a methanogenic microbial consortium grown on sedimentary rocks of various maturities

PubMed Central

Meslé, Margaux; Dromart, Gilles; Haeseler, Frank; Oger, Philippe M.

2015-01-01

Organic-rich shales are populated by methanogenic consortia that are able to degrade the fossilized organic matter into methane gas. To identify the organic fraction effectively degraded, we have sequentially depleted two types of organic-rich sedimentary rocks, shale, and coal, at two different maturities, by successive solvent extractions to remove the most soluble fractions (maltenes and asphaltenes) and isolate kerogen. We show the ability of the consortia to produce methane from all rock samples, including those containing the most refractory organic matter, i.e., the kerogen. Shales yielded higher methane production than lignite and coal. Mature rocks yielded more methane than immature rocks. Surprisingly, the efficiency of the consortia was not influenced by the removal of the easily biodegradable fractions contained in the maltenes and asphaltenes. This suggests that one of the limitations of organic matter degradation in situ may be the accessibility to the carbon and energy source. Indeed, bitumen has a colloidal structure that may prevent the microbial consortia from reaching the asphaltenes in the bulk rock. Solvent extractions might favor the access to asphaltenes and kerogen by modifying the spatial organization of the molecules in the rock matrix. PMID:26136731

DWARF GALAXIES AND THE COSMIC WEB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benitez-Llambay, Alejandro; Abadi, Mario G.; Navarro, Julio F.

2013-02-01

We use a cosmological simulation of the formation of the Local Group of Galaxies to identify a mechanism that enables the removal of baryons from low-mass halos without appealing to feedback or reionization. As the Local Group forms, matter bound to it develops a network of filaments and pancakes. This moving web of gas and dark matter drifts and sweeps a large volume, overtaking many halos in the process. The dark matter content of these halos is unaffected but their gas can be efficiently removed by ram pressure. The loss of gas is especially pronounced in low-mass halos due tomore » their lower binding energy and has a dramatic effect on the star formation history of affected systems. This 'cosmic web stripping' may help to explain the scarcity of dwarf galaxies compared with the numerous low-mass halos expected in {Lambda}CDM and the large diversity of star formation histories and morphologies characteristic of faint galaxies. Although our results are based on a single high-resolution simulation, it is likely that the hydrodynamical interaction of dwarf galaxies with the cosmic web is a crucial ingredient so far missing from galaxy formation models.« less

[Parameters optimization and cleaning efficiency evaluation of attrition scrubbing remediation of Pb-contaminated soil].

PubMed

Yang, Wen; Huang, Jin-lou; Peng, Hui-qing; Li, Si-tuo

2013-09-01

Attrition scrubbing was used to remediate lead contaminated-site soil, and the main purpose was to remove fine particles and lead contaminants from the surface of sand. The optimal parameters of attrition scrubbing were determined by orthogonal experiment, and three soil samples with different lead concentration were subjected to attrition scrubbing experiments. The results showed that the optimal scrubbing parameters were: a solid ratio of 70% dry matter, a temperature of 25 degrees C, an attrition time of 30 min, and an attrition speed of 1200 r x min(-1). Before attrition scrubbing, the screening and analysis of soil showed that in all three soil samples, lead was mainly enriched on sand and fine particles, and the distribution of lead was highly correlated to the organic matter. After attrition scrubbing, the washing efficiency of the original state lead contaminated sand soil in triplicates was 67.61%, 31.71% and 41.01%, respectively, which indicates that attrition scrubbing can remove part of the fine soil and lead contaminants from the surface of sand, to accomplish the purpose of pollutants enrichment. Scanning electron microscopy (SEM) analysis showed that the sand surface became smooth after attrition scrubbing. The results above show that attrition scrubbing has a good washing effect for the remediation of lead contaminated sand soil.

Efficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation

NASA Astrophysics Data System (ADS)

Hawkes, Jeffrey A.; Rossel, Pamela E.; Stubbins, Aron; Butterfield, David; Connelly, Douglas P.; Achterberg, Eric P.; Koschinsky, Andrea; Chavagnac, Valérie; Hansen, Christian T.; Bach, Wolfgang; Dittmar, Thorsten

2015-11-01

Oceanic dissolved organic carbon (DOC) is an important carbon pool, similar in magnitude to atmospheric CO2, but the fate of its oldest forms is not well understood. Hot hydrothermal circulation may facilitate the degradation of otherwise un-reactive dissolved organic matter, playing an important role in the long-term global carbon cycle. The oldest, most recalcitrant forms of DOC, which make up most of oceanic DOC, can be recovered by solid-phase extraction. Here we present measurements of solid-phase extractable DOC from samples collected between 2009 and 2013 at seven vent sites in the Atlantic, Pacific and Southern oceans, along with magnesium concentrations, a conservative tracer of water circulation through hydrothermal systems. We find that magnesium and solid-phase extractable DOC concentrations are correlated, suggesting that solid-phase extractable DOC is almost entirely lost from solution through mineralization or deposition during circulation through hydrothermal vents with fluid temperatures of 212-401 °C. In laboratory experiments, where we heated samples to 380 °C for four days, we found a similar removal efficiency. We conclude that thermal degradation alone can account for the loss of solid-phase extractable DOC in natural hydrothermal systems, and that its maximum lifetime is constrained by the timescale of hydrothermal cycling, at about 40 million years.

Electrochemical wastewater treatment: influence of the type of carbon and of nitrogen on the organic load removal.

PubMed

Fernandes, Annabel; Coelho, João; Ciríaco, Lurdes; Pacheco, Maria José; Lopes, Ana

2016-12-01

Boron-doped diamond (BDD) and Ti/Pt/PbO 2 anodes were utilized to perform the electrodegradation of synthetic samples containing humic acid in the presence of different organic and inorganic carbon-containing and nitrogen-containing compounds. The influence of the chloride ion in the degradation process of the different synthetic samples was also assessed. The results showed that the anodic oxidation process can efficiently degrade recalcitrant compounds such as humic acid. The presence of carbonate in solution enhances the nitrogen removal, whereas it hinders the oxidation of the organic compounds. When organic nitrogen is present, it is converted to NH 4 + , which in turn is oxidized to nitrate and to volatile nitrogen compounds. Hydroxyl radicals are more prone to oxidize the organic nitrogen than the ammonium nitrogen. The presence of chloride enhances the organic matter and nitrogen removal rates, BDD being the anode material that yields the highest removals.

Performance of a half-saturated vertical flow wetland packed with volcanic gravel in stormwater treatment.

PubMed

Chen, Yaoping; Park, Kisoo; Niu, Siping; Kim, Youngchul

2014-01-01

A half-saturated pilot-scale wetland planted with Acorus calamus was built to treat urban stormwater. The design comprises a sedimentation tank for pretreatment, and a vertical flow volcanic gravel wetland bed equipped with a recirculation device. Eighteen rainfall events were monitored in 2012. The treatment system achieved total removal efficiencies of 99.4, 81, 50, and 86% for suspended solids, organic matter, nitrogen and phosphorus, respectively, and 29, 68, and 25% for copper, zinc, and lead, respectively, at a 3-day hydraulic residence time. In the wetland bed, the removal of ammonia, total nitrogen, and zinc were improved by recirculation. Plant uptake provided 18% of nitrogen removal and 39% of phosphorus removal. During the experimental stage, only 1.4% of the pore volume in substrate was reduced due to clogging, implying that the wetland can operate without clogging for a relatively long period.

Method for improved gas-solids separation

DOEpatents

Kusik, C.L.; He, B.X.

1990-11-13

Methods are disclosed for the removal of particulate solids from a gas stream at high separation efficiency, including the removal of submicron size particles. The apparatus includes a cyclone separator type of device which contains an axially mounted perforated cylindrical hollow rotor. The rotor is rotated at high velocity in the same direction as the flow of an input particle-laden gas stream to thereby cause enhanced separation of particulate matter from the gas stream in the cylindrical annular space between the rotor and the sidewall of the cyclone vessel. Substantially particle-free gas passes through the perforated surface of the spinning rotor and into the hollow rotor, from where it is discharged out of the top of the apparatus. Separated particulates are removed from the bottom of the vessel. 4 figs.

Method for improved gas-solids separation

DOEpatents

Kusik, Charles L.; He, Bo X.

1990-01-01

Methods are disclosed for the removal of particulate solids from a gas stream at high separation efficiency, including the removal of submicron size particles. The apparatus includes a cyclone separator type of device which contains an axially mounted perforated cylindrical hollow rotor. The rotor is rotated at high velocity in the same direction as the flow of an input particle-laden gas stream to thereby cause enhanced separation of particulate matter from the gas stream in the cylindrical annular space between the rotor and the sidewall of the cyclone vessel. Substantially particle-free gas passes through the perforated surface of the spinning rotor and into the hollow rotor, from when it is discharged out of the top of the apparatus. Separated particulates are removed from the bottom of the vessel.

Transparent air filter for high-efficiency PM2.5 capture.

PubMed

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-16

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m(-3)). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

Microbial fuel cells for direct electrical energy recovery from urban wastewaters.

PubMed

Capodaglio, A G; Molognoni, D; Dallago, E; Liberale, A; Cella, R; Longoni, P; Pantaleoni, L

2013-01-01

Application of microbial fuel cells (MFCs) to wastewater treatment for direct recovery of electric energy appears to provide a potentially attractive alternative to traditional treatment processes, in an optic of costs reduction, and tapping of sustainable energy sources that characterizes current trends in technology. This work focuses on a laboratory-scale, air-cathode, and single-chamber MFC, with internal volume of 6.9 L, operating in batch mode. The MFC was fed with different types of substrates. This study evaluates the MFC behaviour, in terms of organic matter removal efficiency, which reached 86% (on average) with a hydraulic retention time of 150 hours. The MFC produced an average power density of 13.2 mW/m(3), with a Coulombic efficiency ranging from 0.8 to 1.9%. The amount of data collected allowed an accurate analysis of the repeatability of MFC electrochemical behaviour, with regards to both COD removal kinetics and electric energy production.

Decontamination Efficiencies of Pot-Type Water Purifiers for 131I, 134Cs and 137Cs in Rainwater Contaminated during Fukushima Daiichi Nuclear Disaster

PubMed Central

Higaki, Shogo; Hirota, Masahiro

2012-01-01

Rainwater was contaminated by a large release of radionuclides into the environment during the Fukushima Daiichi nuclear disaster. It became a matter of concern for Japan when several water purification plants detected 131I contamination in the drinking water. In the present study, the decontamination efficiency of two easily obtainable commercial water purifiers were examined for rainwater contaminated with 131I, 134Cs and 137Cs. The water purifiers removed 94.2–97.8% of the 131I and 84.2–91.5% of the 134Cs and 137Cs after one filtration. Seven filtrations removed 98.2–99.6% of the 131I and over 98.0% of the 134Cs and 137Cs. From a practical perspective, over the fourth filtrations were not needed because of no significant improvements after the third filtration. PMID:22615935

Transparent air filter for high-efficiency PM2.5 capture

NASA Astrophysics Data System (ADS)

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-01

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m-3). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

The total amounts of radioactively contaminated materials in forests in Fukushima, Japan

PubMed Central

Hashimoto, Shoji; Ugawa, Shin; Nanko, Kazuki; Shichi, Koji

2012-01-01

There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ 134, 137Cs 1000 kBq m−2) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm3 (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil. PMID:22639724

Application of local exhaust ventilation system and integrated collectors for control of air pollutants in mining company.

PubMed

Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Farasati, Farhad

2012-01-01

Local exhaust ventilation (LEV) systems and integrated collectors were designed and implemented in a mining company in order to control emitted air pollutant from furnaces. The LEV was designed for capture and transition of air pollutants emitted from furnaces to the integrated collectors. The integrated collectors including four high efficiency Stairmand model cyclones for control of particulate matter, a venturi scrubber for control of the fine particles, SO(2) and a part of H(2)S to follow them, and a packed scrubber for treatment of the residual H(2)S and SO(2) were designed. Pollutants concentration were measured to determine system effectiveness. The results showed that the effectiveness of LEV for reducing workplace pollution is 91.83%, 96.32% and 83.67% for dust, SO(2) and H(2)S, respectively. Average removal efficiency of particles by combination of cyclone and venturi scrubber was 98.72%. Average removal efficiency of SO(2) and H(2)S were 95.85% and 47.13% for the venturi scrubber and 68.45% and 92.7% for the packed bed scrubber. The average removal efficiency of SO(2) and H(2)S were increased to 99.1% and 95.95% by the combination of venturi and packed bed scrubbers. According to the results, integrated collectors are a good air pollution control option for industries with economic constraints and ancient technologies.

Evaluation of kenaf fibers as moving bed biofilm carriers in algal membrane photobioreactor.

PubMed

Derakhshan, Zahra; Mahvi, Amir Hossein; Ehrampoush, Mohammad Hassan; Ghaneian, Mohammad Taghi; Yousefinejad, Saeed; Faramarzian, Mohammad; Mazloomi, Seyed Mohammad; Dehghani, Mansooreh; Fallahzadeh, Hossein

2018-05-15

In this lab-scale study, the feasibility of using kenaf fibers as moving bed biofilm carriers in hybrid microalgal membrane photobioreactors (HMPBR) in organic matter and atrazine elimination from real secondary effluent was evaluated. For evaluating the kinetics of biofilm substrate consumption, an experimental model was proposed. Inoculation of wastewater samples with free carriers resulted in the greater removal of target pollutants. Removal efficiency of atrazine and chemical oxygen demand (COD) increased to 27% and 16%, with respect to the control, respectively. The total biomass accumulation in HMPBR exceeded 5g/L, and the microalgae tended to aggregate and attached to biofilm carriers. The removal efficiency of HMPBR improved significantly via inoculation of kenaf fiber carriers with bioremediation microalgal strains (p < 0.01). A lower stabilization ratio (VSS/TSS) was also recorded. The biomass in HMPBR included more lipids and carbohydrates. The results revealed that kenaf fibers could improve and upgrade the biological activity of different wastewater treatment applications, considering the great potential of biofilm carriers and their effluent quality. Copyright © 2018 Elsevier Inc. All rights reserved.

Simultaneous pollutant removal and electricity generation in denitrifying microbial fuel cell with boric acid-borate buffer solution.

PubMed

Chen, Gang; Zhang, Shaohui; Li, Meng; Wei, Yan

2015-01-01

A double-chamber denitrifying microbial fuel cell (MFC), using boric acid-borate buffer solution as an alternative to phosphate buffer solution, was set up to investigate the influence of buffer solution concentration, temperature and external resistance on electricity generation and pollutant removal efficiency. The result revealed that the denitrifying MFC with boric acid-borate buffer solution was successfully started up in 51 days, with a stable cell voltage of 205.1 ± 1.96 mV at an external resistance of 50 Ω. Higher concentration of buffer solution favored nitrogen removal and electricity generation. The maximum power density of 8.27 W/m(3) net cathodic chamber was obtained at a buffer solution concentration of 100 mmol/L. An increase in temperature benefitted electricity generation and nitrogen removal. A suitable temperature for this denitrifying MFC was suggested to be 25 °C. Decreasing the external resistance favored nitrogen removal and organic matter consumption by exoelectrogens.

Oxidation of winery wastewater by sulphate radicals: catalytic and solar photocatalytic activations.

PubMed

Rodríguez-Chueca, Jorge; Amor, Carlos; Mota, Joana; Lucas, Marco S; Peres, José A

2017-10-01

The treatment of winery effluents through sulphate radical-based advanced oxidation processes (SR-AOPs) driven by solar radiation is reported in this study. Photolytic and catalytic activations of peroxymonosulphate (PMS) and persulphate (KPS and SPS) at different pH values (4.5 and 7) were studied in the degradation of organic matter. Portugal is one of the largest wine producers in Europe. The wine making activities generate huge volume of effluents characterized by a variable volume and organic load, being their seasonal nature one of the most important drawbacks. Recently, SR-AOPs are gradually attracting attention as in situ chemical oxidation technologies, instead of hydroxyl radical AOPs (HR-AOPs). The studied concentrations are suitable to obtain notable values of organic matter degradation, with TOC removal around 50%. In general terms, no notable differences were observed between treatments at pH values 4.5 and 7. Photolytic activation of SPS with solar radiation treatments obtained the highest efficiency (28 and 40% of TOC removal with 1 and 50 mM, respectively, at pH 4.5) in comparison to KPS and PMS. The addition of a transition metal as catalyst, such as Fe(II) or Co(II), increased considerably the TOC removal efficiency higher than 50%, but not in all cases. For instance, the combination KPS or PMS with Co(II) at pH 4.5 did not allow to obtain better results than photolytic activation of these persulphate salts. In summary, the use of SR-AOPs could be a serious alternative as tertiary treatment for winery wastewaters.

Evaluation of humic substances removal from leachates originating from solid waste landfills in Rio de Janeiro State, Brazil.

PubMed

Lima, Letícia S M S; De Almeida, Ronei; Quintaes, Bianca R; Bila, Daniele M; Campos, Juacyara C

2017-07-29

This study aimed to evaluate the use of coagulation/flocculation and Fenton processes for the removal of the recalcitrant component, in particular humic substances, from two different leachates generated in the Gericinó and Gramacho landfills in Rio de Janeiro State (Brazil). A coagulation/flocculation process, using FeCl 3 ·6H 2 O as the coagulant, was applied to the two leachate samples. In the case of the leachate from Gericinó landfill, the treatment removed 93% of color, 71% of TOC, 69% of COD, 76% of HS, 73% of humic acids (HA) and 82% of fulvic acids (FA). In addition, there was a 75% reduction in the absorbance at 254 nm, using 3,000 mg L -1 of coagulant. In the case of the leachate from Gramacho landfill, the treatment removed 91% of color, 69% of TOC, 68% of COD, 77% of HS, 75% of HA and 80% of FA. In addition, there was a 70% reduction in the absorbance at 254 nm using the same concentration of coagulant (3,000 mg L -1 ). The Fenton processes, using FeSO 4 ·7H 2 O and H 2 O 2 in a ratio of 1:5, were also applied to the two leachate samples. In the case of the Gericinó leachate, the Fenton treatment removed 95% of color, 75% of TOC, 68% of COD, 82% of HS, 77% of HA and 93% of FA. In addition, there was a 93% reduction in the absorbance at 254 nm. In the case of the Gramacho leachate, the Fenton treatment removed 93% of color, 73% of TOC, 71% of COD, 81% of HS, 76% of HA, 90% of FA, and there was an 84% reduction in the absorbance at 254 nm. The results of humic substances, color, organic matter and aromatic organic matter (absorbance at 254 nm) demonstrate that the coagulation/flocculation and Fenton processes were efficient in the removal of recalcitrant organic matter from landfill leachates.

Tracking changes in composition and amount of dissolved organic matter throughout drinking water treatment plants by comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry.

PubMed

Li, Chunmei; Wang, Donghong; Xu, Xiong; Xu, Meijia; Wang, Zijian; Xiao, Ruiyang

2017-12-31

Dissolved organic matter (DOM) can affect the performance of water treatment processes and produce undesirable disinfection by-products during disinfection. Several studies have been undertaken on the structural characterization of DOM, but its fate during drinking water treatment processes is still not fully understood. In this work, the nontargeted screening method of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) was used to reveal the detailed changes of different chemical classes of compounds in DOM during conventional and advanced drinking water treatment processes at three drinking water treatment plants in China. The results showed that when the dissolved organic carbon removal was low, shifts in the DOM composition could not be detected with the specific ultraviolet absorbance at 254nm, but the changes were clear in the three-dimensional fluorescence excitation-emission matrix or GC×GC-qMS analyses. Coagulation-sedimentation processes selectively removed 37-59% of the nitrogenous compounds, alcohols and aromatic hydrocarbons but increased the concentrations of halogen-containing compounds by 17-26% because of the contact time with chlorine in this step. Filtration was less efficient at removing DOM but preferentially removed 21-60% of the acids. However, other organic matter would be released from the filter (e.g., nitrogenous compounds, acids, and aromatic hydrocarbons). Biological activated carbon (BAC) treatment removed most of the compounds produced from ozonation, particularly ketones, alcohols, halogen-containing compounds and acids. However, it should be noted that certain highly polar or high molecular weight compounds not identified in this study might be released from the BAC bed. After the whole treatment processes, the concentrations of nitrogenous compounds, alcohols, alkenes, aromatic hydrocarbons and ketones were decreased more by the advanced treatment processes than by the conventional treatment processes. Alcohol and ketone removals were probably related to the reduction in protein-like materials. Alkane removal was probably related to the reduction in fulvic acid-like and humic acid-like materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous C and N removal from saline salmon effluents in filter reactors comprising anoxic-anaerobic-aerobic processes: effect of recycle ratio.

PubMed

Giustinianovich, Elisa A; Aspé, Estrella R; Huiliñir, César E; Roeckel, Marlene D

2014-01-01

Salmon processing generates saline effluents with high protein load. To treat these effluents, three compact tubular filter reactors were installed and an integrated anoxic/anaerobic/aerobic process was developed with recycling flow from the reactor's exit to the inlet stream in order to save organic matter (OM) for denitrification. The reactors were aerated in the upper section with recycle ratios (RR) of 0, 2, and 10, respectively, at 30°C. A tubular reactor behave as a plug flow reactor when RR = 0, and as a mixed flow reactor when recycle increases, thus, different RR values were used to evaluate how it affects the product distribution and the global performance. Diluted salmon process effluent was prepared as substrate. Using loads of 1.0 kg COD m(-3)d(-1) and 0.15 kg total Kjeldahl nitrogen (TKN) m(-3)d(-1) at HRT of 2 d, 100% removal efficiencies for nitrite and nitrate were achieved in the anoxic-denitrifying section without effect of the dissolved oxygen in the recycled flow on denitrification. Removals >98% for total organic carbon (TOC) was achieved in the three reactors. The RR had no effect on the TOC removal; nevertheless a higher efficiency in total nitrogen removal in the reactor with the highest recycle ratio was observed: 94.3% for RR = 10 and 46.6% for RR = 2. Results showed that the proposed layout with an alternative distribution in a compact reactor can efficiently treat high organic carbon and nitrogen concentrations from a saline fish effluent with OM savings in denitrification.

Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

PubMed Central

Gao, Lidi; Kano, Naoki; Sato, Yuichi; Li, Chong; Zhang, Shuang; Imaizumi, Hiroshi

2012-01-01

In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90–100% using a precipitation method with alkaline solution. PMID:22693485

Single and combined effects of phosphate, silicate, and natural organic matter on arsenic removal from soft and hard groundwater using ferric chloride

NASA Astrophysics Data System (ADS)

Chanpiwat, Penradee; Hanh, Hoang Thi; Bang, Sunbaek; Kim, Kyoung-Woong

2017-06-01

In order to assess the effects of phosphate, silicate and natural organic matter (NOM) on arsenic removal by ferric chloride, batch coprecipitation experiments were conducted over a wide pH range using synthetic hard and soft groundwaters, similar to those found in northern Vietnam. The efficiency of arsenic removal from synthetic groundwater by coprecipitation with FeCl3 was remarkably decreased by the effects of PO4 3-, SiO4 4- and NOM. The negative effects of SiO4 4- and NOM on arsenic removal were not as strong as that of PO4 3-. Combining PO4 3- and SiO4 4- increased the negative effects on both arsenite (As3+) and arsenate (As5+) removal. The introduction of NOM into the synthetic groundwater containing both PO4 3- and SiO4 4- markedly magnified the negative effects on arsenic removal. In contrast, both Ca2+ and Mg2+ substantially increased the removal of As3+ at pH 8-12 and the removal of As5+ over the entire pH range. In the presence of Ca2+ and Mg2+, the interaction of NOM with Fe was either removed or the arsenic binding to Fe-NOM colloidal associations and/or dissolved complexes were flocculated. Removal of arsenic using coprecipitation by FeCl3 could not sufficiently reduce arsenic contents in the groundwater (350 μg/L) to meet the WHO guideline for drinking water (10 μg/L), especially when the arsenic-rich groundwater also contains co-occurring solutes such as PO4 3-, SiO4 4- and NOM; therefore, other remediation processes, such as membrane technology, should be introduced or additionally applied after this coprecipitation process, to ensure the safety of drinking water.

Removal of refractory organics in nanofiltration concentrates of municipal solid waste leachate treatment plants by combined Fenton oxidative-coagulation with photo--Fenton processes.

PubMed

Li, Jiuyi; Zhao, Lei; Qin, Lele; Tian, Xiujun; Wang, Aimin; Zhou, Yanmei; Meng, Liao; Chen, Yong

2016-03-01

Removal of the refractory organic matters in leachate brines generated from nanofiltration unit in two full-scale municipal solid waste landfill leachate treatment plants was investigated by Fenton oxidative-coagulation and ultraviolet photo - Fenton processes in this study. Fenton oxidative-coagulation was performed under the condition of an initial pH of 5.0 and low H2O2/Fe(2+) ratios. After precipitate separation, the remaining organic constituents were further oxidized by photo - Fenton process. For both leachate brines with varying pollution strength, more than 90% COD and TOC reductions were achieved at H2O2/Fe(2+) dosages of 35 mM/8 mM and 90 mM/10 mM, respectively. The effluent COD ranged 120-160 mg/L under the optimal operating conditions, and the biodegradability was increased significantly. Fenton oxidative-coagulation was demonstrated to contribute nearly 70% overall removal of organic matters. In the combined processes, the efficiency of hydrogen peroxide varied from 216 to 228%, which may significantly reduce the operating cost of conventional Fenton method. Six phthalic acid esters and thirteen polycyclic aromatic hydrocarbons were found in leachate brines, and, on the average, around 80% phthalic acid esters and 90% polycyclic aromatic hydrocarbons were removed by the combined treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tracking changes in the optical properties and molecular composition of dissolved organic matter during drinking water production.

PubMed

Lavonen, E E; Kothawala, D N; Tranvik, L J; Gonsior, M; Schmitt-Kopplin, P; Köhler, S J

2015-11-15

Absorbance, 3D fluorescence and ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) were used to explain patterns in the removal of chromophoric and fluorescent dissolved organic matter (CDOM and FDOM) at the molecular level during drinking water production at four large drinking water treatment plants in Sweden. When dissolved organic carbon (DOC) removal was low, shifts in the dissolved organic matter (DOM) composition could not be detected with commonly used DOC-normalized parameters (e.g. specific UV254 absorbance - SUVA), but was clearly observed by using differential absorbance and fluorescence or ESI-FT-ICR-MS. In addition, we took a novel approach by identifying how optical parameters were correlated to the elemental composition of DOM by using rank correlation to connect optical properties to chemical formulas assigned to mass peaks from FT-ICR-MS analyses. Coagulation treatment selectively removed FDOM at longer emission wavelengths (450-600 nm), which significantly correlated with chemical formulas containing oxidized carbon (average carbon oxidation state ≥ 0), low hydrogen to carbon ratios (H/C: average ± SD = 0.83 ± 0.13), and abundant oxygen-containing functional groups (O/C = 0.62 ± 0.10). Slow sand filtration was less efficient in removing DOM, yet selectively targeted FDOM at shorter emission wavelengths (between 300 and 450 nm), which commonly represents algal rather than terrestrial sources. This shorter wavelength FDOM correlated with chemical formulas containing reduced carbon (average carbon oxidation state ≤ 0), with relatively few carbon-carbon double bonds (H/C = 1.32 ± 0.16) and less oxygen per carbon (O/C = 0.43 ± 0.10) than those removed during coagulation. By coupling optical approaches with FT-ICR-MS to characterize DOM, we were for the first time able to confirm the molecular composition of absorbing and fluorescing DOM selectively targeted during drinking water treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Impacts of potassium ferrate(VI) on the growth and organic matter accumulation, production, and structural changes in the cyanobacterium Microcystis aeruginosa.

PubMed

Liu, Shu-Yu; Xu, Jingling; Chen, Wen-Li; David, Berthold E; Wu, Minghong; Ma, Fang

2017-04-01

Cyanobacterial blooms generated by nutrient addition into aquatic systems pose serious risks to ecosystems and human health. Though there are established chemical, physical, and biological means of eradication, more efficient and environmentally friendly measures are desired. This study investigates the effect of potassium ferrate(VI) on the growth and intracellular and extracellular organic matter accumulations of the cyanobacterium Microcystis aeruginosa. Cultures were inoculated with three separate concentrations of potassium ferrate(VI) (3, 15, 30 mg L -1 ) and monitored by measuring chlorophyll-a (Chl-a) and intracellular/extracellular dissolved organic carbon. Results show that ferrate(VI) addition effectively removed the microalgae from the medium, as indicated by the reduction of Chl-a. Organic matter accumulation of the microalgae was also affected by ferrate(VI) treatment; fluorescence EEM spectra show details of changing intracellular dissolved organic matter (IDOM) and extracellular dissolved organic matter (EDOM). A new peak appeared in the EDOM indicating altered humic and proteinaceous compounds. This study demonstrates that ferrate(VI) is a potential treatment for the water contaminated with the toxic microalgae M. aeruginosa.

Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters and Packed Beds of Granular Materials

NASA Technical Reports Server (NTRS)

Perry, J. L.; Agui, J. H.; Vijayakimar, R

2016-01-01

Contaminants generated aboard crewed spacecraft by diverse sources consist of both gaseous chemical contaminants and particulate matter. Both HEPA media filters and packed beds of granular material, such as activated carbon, which are both commonly employed for cabin atmosphere purification purposes have efficacy for removing nanoparticulate contaminants from the cabin atmosphere. The phenomena associated with particulate matter removal by HEPA media filters and packed beds of granular material are reviewed relative to their efficacy for removing fine (less than 2.5 micrometers) and ultrafine (less than 0.01 micrometers) sized particulate matter. Considerations are discussed for using these methods in an appropriate configuration to provide the most effective performance for a broad range of particle sizes including nanoparticulates.

Experimentation on the anaerobic filter reactor for biogas production using rural domestic wastewater

NASA Astrophysics Data System (ADS)

Leju Celestino Ladu, John; Lü, Xi-wu; Zhong, Zhaoping

2017-08-01

The biogas production from anaerobic filter (AF) reactor was experimented in Taihu Lake Environmental Engineering Research Center of Southeast University, Wuxi, China. Two rounds of experimental operations were conducted in a laboratory scale at different Hydraulic retention time (HRT) and wastewater temperature. The biogas production rate during the experimentation was in the range of 4.63 to 11.78 L/d. In the first experimentation, the average gas production rate was 10.08 L/d, and in the second experimentation, the average gas production rate was 4.97 L/d. The experimentation observed the favorable Hydraulic Retention Time and wastewater temperature in AF was three days and 30.95°C which produced the gas concentration of 11.78 L/d. The HRT and wastewater temperature affected the efficiency of the AF process on the organic matter removal and nutrients removal as well. It can be deduced from the obtained results that HRT and wastewater temperature directly affects the efficiency of the AF reactor in biogas production. In conclusion, anaerobic filter treatment of organic matter substrates from the rural domestic wastewater increases the efficiency of the AF reactor on biogas production and gives a number of benefits for the management of organic wastes as well as reduction in water pollution. Hence, the operation of the AF reactor in rural domestic wastewater treatment can play an important element for corporate economy of the biogas plant, socio-economic aspects and in the development of effective and feasible concepts for wastewater management, especially for people in rural low-income areas.

Remediation and desorption kinetics of pyrene from kaolinite co-contaminated with heavy metals at various organic matter contents

NASA Astrophysics Data System (ADS)

Saeedi, Mohsen; Li, Loretta Y.; Grace, John R.

2017-04-01

Soils co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals are challenging for remediation. In the present study desorption of pyrene in kaolinite, co-contaminated by Ni, Pb and Zn, was examined by combinations of surfactants and chelating agents such as Triton X-100, Tween 80, Ethylene diamine tetra acetic acid (EDTA) and citric acid. Results showed that a combination of Triton X-100 (7.5 % w/w) + EDTA (0.01 M) and Tween 80 (7.5 % w/w) + EDTA (0.01 M) were effective in simultaneously desorbing both types of contaminants. Batch desorption tests were conducted using single and combined enhancing agents containing Triton X-100 and Tween 80 as non-ionic surfactants, EDTA as a chelating agent, and citric acid as an organic acid. The solution with the highest removal efficiency was the combined solution containing Triton X-100 (7.5 % w/w) + EDTA (0.01M). Triton X-100 (7.5% w/w) + EDTA (0.01M) led to removal efficiencies of 88% for pyrene in base kaolinite. Batch desorption kinetic experiments were performed using Triton X-100 (7.5% w/w) + EDTA (0.01M). During the first 24 h, desorption was rapid. Organic matter content in the kaolinite led to a reduction in the desorption rate of the contaminants. The desorption kinetic data were well fitted by a pseudo-second-order kinetic model.

Effect of packing material on organic matter removal efficiency in an anaerobic-aerobic baffled bioreactor.

PubMed

Tabla-Hernandez, Jacobo; Lopez-Galvan, Edgar

2018-04-01

The aim of the present work was to study the effect of packing material on the organic matter removal efficiency (OMRE) in an anaerobic-aerobic baffled bioreactor (AAB). For this purpose, two different experiments were conducted with two types of packing material: activated carbon (AC) particles and polyurethane foam (PF). The system consisted of two treatments; the first one was anaerobic, where hydrolysis, acetogenesis and methanogenesis took place. In anaerobic chambers, there were no packing materials and the operating conditions were the same in both experiments. The second treatment was aerobic and both materials were placed at different times as a bedding. The parameters measured were chemical oxygen demand (COD), dissolved chemical oxygen demand (COD d ), total organic carbon (TOC), nitrate concentration (NO 3 - ), ammonium concentration (NH 4 + ), electric conductivity (σ), alkalinity (Alky) and hydrogen potential (pH). Paired t-Student test showed that there was no significant difference in the OMRE in anaerobic treatment, whereas there was in aerobic treatment, due to the effect of packing material. NH 4 + and NO 3 - showed a negative Pearson correlation in both experiments, indicating the presence of the nitrification process in the aerobic chamber. AAB packed with PF had better performance at obtaining an OMRE of around 63%, whereas AAB packed with AC presented an OMRE of around 51%.

Degradation of anti-inflammatory drugs in municipal wastewater by heterogeneous photocatalysis and electro-Fenton process.

PubMed

Villanueva-Rodríguez, Minerva; Bello-Mendoza, Ricardo; Hernández-Ramírez, Aracely; Ruiz-Ruiz, Edgar J

2018-03-01

Non-steroidal anti-inflammatory drugs (NSAID) are compounds frequently found in municipal wastewater and their degradation by conventional wastewater treatment plants (WWTP) is generally incomplete. This study compared the efficiency of two advanced oxidation processes (AOP), namely heterogeneous photocatalysis (HP) and electro-Fenton (EF), in the degradation of a mixture of common NSAID (diclofenac, ibuprofen and naproxen) dissolved in either deionized water or effluent from a WWTP. Both processes were effective in degrading the NSAID mixture and the trend of degradation was as follows, diclofenac > naproxen > ibuprofen. EF with a current density of 40 mA cm -2 and 0.3 mmol Fe 2+  L -1 was the most efficient process to mineralize the organic compounds, achieving up to 92% TOC removal in deionized water and 90% in the WWTP effluent after 3 h of reaction. HP with 1.4 g TiO 2  L -1 at pH 7 under sunlight, produced 85% TOC removal in deionized water and 39% in WWTP effluent also after 3 h treatment. The lower TOC removal efficiency shown by HP with the WWTP effluent was attributed mainly to the scavenging of reactive species by background organic matter in the wastewater. On the contrary, inorganic ions in the wastewater may produce oxidazing species during the EF process, which contributes to a higher degradation efficiency. EF is a promising option for the treatment of anti-inflammatory pharmaceuticals in municipal WWTP at competitive electrical energy efficiencies.

The Effect of COD Concentration Containing Leaves Litter, Canteen and Composite Waste to the Performance of Solid Phase Microbial Fuel Cell (SMFC)

NASA Astrophysics Data System (ADS)

Samudro, Ganjar; Syafrudin; Nugraha, Winardi Dwi; Sutrisno, Endro; Priyambada, Ika Bagus; Muthi'ah, Hilma; Sinaga, Glory Natalia; Hakiem, Rahmat Tubagus

2018-02-01

This research is conducted to analyze and determine the optimum of COD concentration containing leaves litter, canteen and composite waste to power density and COD removal efficiency as the indicator of SMFC performance. COD as the one of organic matter parameters perform as substrate, nutrient and dominating the whole process of SMFC. Leaves litter and canteen based food waste were obtained from TPST UNDIP in Semarang and treated in SMFC reactor. Its reactor was designed 2 liter volume and equipped by homemade graphene electrodes that were utilized at the surface of organic waste as cathode and in a half of reactor height as anode. COD concentration was initially characterized and became variations of initial COD concentration. Waste volume was maintained 2/3 of volume of reactor. Bacteria sources as the important process factor in SMFC were obtained from river sediment which contain bacteroides and exoelectrogenic bacteria. Temperature and pH were not maintained while power density and COD concentration were periodically observed and measured during 44 days. The results showed that power density up to 4 mW/m2 and COD removal efficiency performance up to 70% were reached by leaves litter, canteen and composite waste at days 11 up to days 44 days. Leaves litter contain 16,567 mg COD/l providing higher COD removal efficiency reached approximately 87.67%, more stable power density reached approximately 4.71 mW/m2, and faster optimum time in the third day than canteen based food waste and composite waste. High COD removal efficiency has not yet resulted in high power density.

Reducing patients' exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters.

PubMed

Brown, Kathleen Ward; Minegishi, Taeko; Allen, Joseph G; McCarthy, John F; Spengler, John D; MacIntosh, David L

2014-08-01

Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used "each pass removal efficiency" applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients.

The role of heterotrophic microorganism Galactomyces sp. Z3 in improving pig slurry bioleaching.

PubMed

Zhou, Jun; Zheng, Guanyu; Zhou, Lixiang; Liu, Fenwu; Zheng, Chaocheng; Cui, Chunhong

2013-01-01

The feasibility of removing heavy metals and eliminating pathogens from pig slurry through bioleaching involving the fungus Galactomyces sp. Z3 and two acidophilic thiobacillus (A. ferrooxidans LX5 and A. thiooxidans TS6) was investigated. It was found that the isolated pig slurry dissolved organic matter (DOM) degrader Z3 was identified as Galactomyces sp. Z3, which could grow well at pH 2.5-7 and degrade pig slurry DOM from 1973 to 942 mg/l within 48 h. During the successive multi-batch bioleaching systems, the co-inoculation of pig slurry degrader Galactomyces sp. Z3 and the two Acidithiobacillus species could improve pig slurry bioleaching efficiency compared to the single system without Galactomyces sp. Z3. The removal efficiency of Zn and Cu exceeded 94% and 85%, respectively. In addition, the elimination efficiencies of pathogens, including both total coliform and faecal coliform counts, exceeded 99% after bioleaching treatment. However, the counts of Galactomyces sp. Z3 decreased with the fall of pH and did not restore to the initial level during successive multi-batch bioleaching systems, and it is necessary to re-inoculate Galactomyces sp. Z3 cells into the bioleaching system to maintain its role in degrading pig slurry DOM. Therefore, a bioleaching technique involving both Galactomyces sp. Z3 and Acidithiobacillus species is an efficient method for removing heavy metals and eliminating pathogens from pig slurry.

A wind tunnel study on the effect of trees on PM2.5 distribution around buildings.

PubMed

Ji, Wenjing; Zhao, Bin

2018-03-15

Vegetation, especially trees, is effective in reducing the concentration of particulate matter. Trees can efficiently capture particles, improve urban air quality, and may further decrease the introduction of outdoor particles to indoor air. The objective of this study is to investigate the effects of trees on particle distribution and removal around buildings using wind tunnel experiments. The wind tunnel is 18m long, 12m wide, and 3.5m high. Trees were modeled using real cypress branches to mimic trees planted around buildings. At the inlet of the wind tunnel, a "line source" of particles was released, simulating air laden with particulate matter. Experiments with the cypress tree and tree-free models were conducted to compare particle concentrations around the buildings. The results indicate that cypress trees clearly reduce PM 2.5 concentrations compared with the tree-free model. The cypress trees enhanced the PM 2.5 removal rate by about 20%. The effects of trees on PM 2.5 removal and distribution vary at different heights. At the base of the trees, their effect on reducing PM 2.5 concentrations is the most significant. At a great height above the treetops, the effect is almost negligible. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of Elemental Mercury Oxidation Across Vanadium and Cerium Based Catalysts in Coal Combustion Flue Gas: Catalytic Performances and Particulate Matter Effects.

PubMed

Wan, Qi; Yao, Qiang; Duan, Lei; Li, Xinghua; Zhang, Lei; Hao, Jiming

2018-03-06

This paper discussed the field test results of mercury oxidation activities over vanadium and cerium based catalysts in both coal-fired circulating fluidized bed boiler (CFBB) and chain grate boiler (CGB) flue gases. The characterizations of the catalysts and effects of flue gas components, specifically the particulate matter (PM) species, were also discussed. The catalytic performance results indicated that both catalysts exhibited mercury oxidation preference in CGB flue gas rather than in CFBB flue gas. Flue gas component studies before and after dust removal equipment implied that the mercury oxidation was well related to PM, together with gaseous components such as NO, SO 2 , and NH 3 . Further investigations demonstrated a negative PM concentration-induced effect on the mercury oxidation activity in the flue gases before the dust removal, which was attributed to the surface coverage by the large amount of PM. In addition, the PM concentrations in the flue gases after the dust removal failed in determining the mercury oxidation efficiency, wherein the presence of different chemical species in PM, such as elemental carbon (EC), organic carbon (OC) and alkali (earth) metals (Na, Mg, K, and Ca) in the flue gases dominated the catalytic oxidation of mercury.

Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes.

PubMed

Oturan, Nihal; van Hullebusch, Eric D; Zhang, Hui; Mazeas, Laurent; Budzinski, Hélène; Le Menach, Karyn; Oturan, Mehmet A

2015-10-20

In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals ((•)OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants.

Effect of Permanganate Preoxidation to Natural Organic Matter and Disinfection by-Products Formation Potential Removal

NASA Astrophysics Data System (ADS)

Hidayah, E. N.; Yeh, H. H.

2018-01-01

Laboratory scale experiments was conducted to examine effect of permanganate (KMnO4) peroxidation in characterizing and to remove natural organic matter (NOM) in source water. The experimental results shows that increasing permanganate dosage could decreased aromatic matter, as indicated by decreasing UV254 and SUVA value about 23% and 28%, respectively. It seems that permanganate preoxidation caused the breakdown of high molecular weight (MW) organics into low MW ones, as represented by increasing NPDOC about 10%. Further, disinfection by-products formation potential (DBPFP) in terms of trihalomethanes formation potential (THMFP) and haloacetic acid formation potential (HAAP) decreased about 15% and 23%, respectively. HAAFP removal is higher than THMFP removal and that DPBFP removal is consistent with UV254 and NPDOC removal.

Constraints on the utility of MnO2 cartridge method for the extraction of radionuclides: A case study using 234Th

USGS Publications Warehouse

Baskaran, M.; Swarzenski, P.W.; Biddanda, B.A.

2009-01-01

[1] Large volume (102-103 L) seawater samples are routinely processed to investigate the partitioning of particle reactive radionuclides and Ra between solution and size-fractionated suspended particulate matter. One of the most frequently used methods to preconcentrate these nuclides from such large volumes involves extraction onto three filter cartridges (a prefilter for particulate species and two MnO2-coated filters for dissolved species) connected in series. This method assumes that the extraction efficiency is uniform for both MnO2-coated cartridges, that no dissolved species are removed by the prefilter, and that any adsorbed radionuclides are not desorbed from the MnO2-coated cartridges during filtration. In this study, we utilized 234Th-spiked coastal seawater and deionized water to address the removal of dissolved Th onto prefilters and MnO2-coated filter cartridges. Experimental results provide the first data that indicate (1) a small fraction of dissolved Th (<6%) can be removed by the prefilter cartridge; (2) a small fraction of dissolved Th (<5%) retained by the MnO2 surface can also be desorbed, which undermines the assumption of uniform extraction efficiency for Th; and (3) the absolute and relative extraction efficiencies can vary widely. These experiments provide insight on the variability of the extraction efficiency of MnO 2-coated filter cartridges by comparing the relative and absolute efficiencies and recommend the use of a constant efficiency on the combined activity from two filter cartridges connected in series for future studies of dissolved 234Th and other radionuclides in natural waters using sequential filtration/extraction methods. ?? 2009 by the American Geophysical Union.

In-situ identification of iron electrocoagulation speciation and application for natural organic matter (NOM) removal.

PubMed

Dubrawski, Kristian L; Mohseni, Madjid

2013-09-15

In this work, iron speciation in electrocoagulation (EC) was studied to determine the impact of operating parameters on natural organic matter (NOM) removal from natural water. Two electrochemical EC parameters, current density (i) and charge loading rate (CLR), were investigated. Variation of these parameters led to a near unity current efficiency (φ = 0.957 ± 0.03), at any combination of i in a range of 1-25 mA/cm(2) and CLR in a range of 12-300 C/L/min. Higher i and CLR led to a higher bulk pH and limited the amount of dissolved oxygen (DO) reduced at the cathode surface due to mass transfer limitations. A low i (1 mA/cm(2)) and intermediate CLR (60 C/L/min) resulted in low bulk DO (<2.5 mg/L), where green rust (GR) was identified by in-situ Raman spectroscopy as the primary crystalline electrochemical product. Longer electrolysis times at higher i led to magnetite (Fe3O4) formation. Both higher (300 C/L/min) and lower (12 C/L/min) CLR values led to increased DO and/or increased pH, with lepidocrocite (γ-FeOOH) as the only crystalline species observed. The NOM removal of the three identified species was compared, with conditions leading to GR formation showing the greatest dissolved organic carbon removal, and highest removal of the low apparent molecular weight (<550 Da) chromophoric NOM fraction, determined by high performance size exclusion chromatography. Copyright © 2013 Elsevier Ltd. All rights reserved.

Application of advanced characterization techniques to assess DOM treatability of micro-polluted and un-polluted drinking source waters in China.

PubMed

Wang, Dongsheng; Xing, Linan; Xie, Jiankun; Chow, Christopher W K; Xu, Zhizhen; Zhao, Yanmei; Drikas, Mary

2010-09-01

China has a very complex water supply system which relies on many rivers and lakes. As the population and economic development increases, water quality is greatly impacted by anthropogenic processes. This seriously affects the character of the dissolved organic matter (DOM) and imposes operational challenges to the water treatment facilities in terms of process optimization. The aim of this investigation was to compare selected drinking water sources (raw) with different DOM character, and the respective treated waters after coagulation, using simple organic characterization techniques to obtain a better understanding of the impact of source water quality on water treatment. Results from the analyses of selected water samples showed that the dissolved organic carbon (DOC) of polluted waters is generally higher than that of un-polluted waters, but the specific UV absorbance value has the opposite trend. After resolving the high performance size exclusion chromatography (HPSEC) peak components of source waters using peak fitting, the twelve waters studied can be divided into two main groups (micro-polluted and un-polluted) by using cluster analysis. The DOM removal efficiency (treatability) of these waters has been compared using four coagulants. For water sources allocated to the un-polluted group, traditional coagulants (Al(2)(SO(4))(3) and FeCl(3)) achieved better removal. High performance poly aluminum chloride, a new type of composite coagulant, performed very well and more efficiently for polluted waters. After peak fitting the HPSEC chromatogram of each of the treated waters, average removal efficiency of the profiles can be calculated and these correspond well with DOC and UV removal. This provides a convenient tool to assess coagulation removal and coagulant selection. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Some properties of a granular activated carbon-sequencing batch reactor (GAC-SBR) system for treatment of textile wastewater containing direct dyes.

PubMed

Sirianuntapiboon, Suntud; Sadahiro, Ohmomo; Salee, Paneeta

2007-10-01

Resting (living) bio-sludge from a domestic wastewater treatment plant was used as an adsorbent of both direct dyes and organic matter in a sequencing batch reactor (SBR) system. The dye adsorption capacity of the bio-sludge was not increased by acclimatization with direct dyes. The adsorption of Direct Red 23 and Direct Blue 201 onto the bio-sludge was almost the same. The resting bio-sludge showed higher adsorption capacity than the autoclaved bio-sludge. The resting bio-sludge that was acclimatized with synthetic textile wastewater (STWW) without direct dyes showed the highest Direct Blue 201, COD, and BOD(5) removal capacities of 16.1+/-0.4, 453+/-7, and 293+/-9 mg/g of bio-sludge, respectively. After reuse, the dye adsorption ability of deteriorated bio-sludge was recovered by washing with 0.1% sodium dodecyl sulfate (SDS) solution. The direct dyes in the STWW were also easily removed by a GAC-SBR system. The dye removal efficiencies were higher than 80%, even when the system was operated under a high organic loading of 0.36kgBOD(5)/m(3)-d. The GAC-SBR system, however, showed a low direct dye removal efficiency of only 57+/-2.1% with raw textile wastewater (TWW) even though the system was operated with an organic loading of only 0.083kgBOD(5)/m(3)-d. The dyes, COD, BOD(5), and total kjeldalh nitrogen removal efficiencies increased up to 76.0+/-2.8%, 86.2+/-0.5%, 84.2+/-0.7%, and 68.2+/-2.1%, respectively, when 0.89 g/L glucose (organic loading of 0.17kgBOD(5)/m(3)-d) was supplemented into the TWW.

Effect of recirculation on organic matter removal in a hybrid constructed wetland system.

PubMed

Ayaz, S C; Findik, N; Akça, L; Erdoğan, N; Kinaci, C

2011-01-01

This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems caused by small communities in Turkey. Pilot-scale treatment of a small community's wastewater was performed over a period of more than 2 years in order to show applicability of these systems. The present study involves removal of organic matter and suspended solids in serially operated horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system (TSCW). Wastewater was first introduced into the horizontal sub-surface flow system and then the vertical flow system before being discharged. Recirculation of the effluent was tested in the system. When the recirculation ratio was 100%, average removal efficiencies for TSCW were 91 +/- 4% for COD, 83 +/- 10% for BOD and 96 +/- 3% for suspended solids with average effluent concentrations of 9 +/- 5 mg/L COD, 6 +/- 3 mg/L BOD and 1 mg/L for suspended solids. Comparing non-recirculation and recirculation periods, the lowest effluent concentrations were obtained with a 100% recirculation ratio. The effluent concentrations met the Turkish regulations for discharge limits of COD, BOD and TSS in each case. The study showed that a hybrid constructed wetland system with recirculation is a very effective method of obtaining very low effluent organic matter and suspended solids concentrations downstream of anaerobic pretreatment of domestic wastewaters in small communities.

In situ removal of arsenic from groundwater by using permeable reactive barriers of organic matter/limestone/zero-valent iron mixtures.

PubMed

Gibert, O; de Pablo, J; Cortina, J-L; Ayora, C

2010-08-01

In this study, two mixtures of municipal compost, limestone and, optionally, zero-valent iron were assessed in two column experiments on acid mine treatment. The effluent solution was systematically analysed throughout the experiment and precipitates from both columns were withdrawn for scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry analysis and, from the column containing zero-valent iron, solid digestion and sequential extraction analysis. The results showed that waters were cleaned of arsenic, metals and acidity, but chemical and morphological analysis suggested that metal removal was not due predominantly to biogenic sulphide generation but to pH increase, i.e. metal (oxy)hydroxide and carbonate precipitation. Retained arsenic and metal removal were clearly associated to co-precipitation with and/or sorption on iron and aluminum (oxy)hydroxides. An improvement on the arsenic removal efficiency was achieved when the filling mixture contained zero-valent iron. Values of arsenic concentrations were then always below 10 microg/L.

A PRELIMINARY EXPERIMENT ON DENITRIFICATION OF WASTE LANDFILL LEACHATE

NASA Astrophysics Data System (ADS)

Wada, Nariaki; Nakamichi, Tamihiro; Yagi, Masahiro; Matsumoto, Toshihide; Kugimiya, Akikazu; Michioku, Kohji

A laboratory experiment on denitrification was carried out in order to reduce nitrogen load from municipal landfill leachate. Nitrogen was efficiently removed by feeding sludge of the leachate pond into the tanks, which could activate denitrification bacteria. Although inorganic reducing agent such as iron powder was not able to make the whole water mass anoxic, denitrification took place by supplying organic matters such as methanol, hydrogen feeding agent, etc.. It is considered that small amount of anoxic water film produced on surfaces of container and carriers might contribute to denitrification, although the bulk water is kept aerobic. It is found that organic matters contained in the leachate is so insufficient that nitrification liquid circulation does not work well for denitrification.

Nine-year response of hardwood understory to organic matter removal and soil compaction

Treesearch

Felix Ponder

2008-01-01

The effects of three levels of organic matter removal (OMR) and three levels of soil compaction (SC) on the development of understory vegetation in a central hardwood forest were evaluated 9 years after treatments were applied as part of a national program of long-term soil productivity research. The three levels of biomass removal (OMR) were removal of merchantable...

Removal of natural organic matter from water using ion-exchange resins and cyclodextrin polyurethanes

NASA Astrophysics Data System (ADS)

Nkambule, T. I.; Krause, R. W.; Mamba, B. B.; Haarhoff, J.

Natural organic matter (NOM) consists of a complex mixture of naturally occurring organic compounds. Although it is not considered toxic by itself, NOM present during water disinfection may result in the formation of disinfection by-products (DBPs), many of which are either carcinogenic or mutagenic. Although it is difficult to completely characterize NOM due to its complex and large structure, a consideration of its structure is necessary for a better understanding of the mechanism of NOM removal from water. In this study, water from the Vaalkop water treatment plant was characterized for its NOM composition by fractionation over ion-exchange resins. Fractionation at different pH with different resins resulted in the isolation of the neutral, basic and acidic fractions of both the hydrophobic and hydrophilic NOM. The hydrophilic basic fraction was found to be the most abundant fraction in the source water. Each of the isolated NOM fractions were percolated through cyclodextrin (CD) polyurethanes, resulting in an adsorption efficiency of between 6% and 33%. The acidic fractions were the most adsorbed fractions by the CD polyurethanes, while the neutral fractions being the least adsorbed. The water samples were then subjected to an ozonation regime at the treatment plant and then fractionated as before. As expected there were decreases of the neutral and basic fractions after ozonation. The application of CD polyurethanes to the fractions after ozonation resulted in a removal efficiency of up to 59%, nearly double that of the non-treated sample. Also, in the case of the ozone pre-treated samples, it was mainly the hydrophilic basic fraction which was removed. All the fractions were subjected to a chlorination test to determine the trihalomethane (THM) formation potential. All six NOM fractions resulted in THM formation, but the hydrophilic basic fraction was found to be the most reactive and formed the highest THM concentration. The effect of the combination of ozone and cyclodextrin polyurethane resulted in a relatively good capability to remove NOM from water as evidenced by an up overall 88% reduction of the hydrophilic acidic fraction.

Novel Hollow Fiber Air Filters for the Removal of Ultrafine Particles in PM2.5 with Repetitive Usage Capability.

PubMed

Li, Manqing; Feng, Yingnan; Wang, Kaiyu; Yong, Wai Fen; Yu, Liya; Chung, Tai-Shung

2017-09-05

Severe air pollution has become a global concern, and there is a pressing need to develop effective and efficient air filters for removing airborne particulate matters (PMs). In this work, a highly permeable poly(ether sulfone) (PES) based hollow fiber membrane was developed via a one-step dry-jet wet spinning. For the first time, a hollow fiber membrane was used in removing the ultrafine particles (PMs with aerodynamic equivalent diameters of less than 100 nm) in PM 2.5 . The novel air filter was designed to possess the synergistic advantages of porous filters and fibrous filters with a sievelike outer surface and a fibrouslike porous substrate. A filtration efficiency of higher than 99.995% could be easily achieved when the self-support hollow fiber was challenged with less than 300 nm particulates. Without losses of the structural advantages, we have demonstrated that the permeation properties of the hollow fiber membrane can be facilely tailored via manipulation of the dope and bore fluid formulations. Various cleaning strategies were explored to regenerate the membrane performance after fouling. Both water rinse and backwash showed effectiveness to restore the membrane permeance for repetitive usage.

Enhancing biodegradation and energy generation via roughened surface graphite electrode in microbial desalination cell.

PubMed

Ebrahimi, Atieh; Yousefi Kebria, Daryoush; Najafpour Darzi, Ghasem

2017-09-01

The microbial desalination cell (MDC) is known as a newly developed technology for water and wastewater treatment. In this study, desalination rate, organic matter removal and energy production in the reactors with and without desalination function were compared. Herein, a new design of plain graphite called roughened surface graphite (RSG) was used as the anode electrode in both microbial fuel cell (MFC) and MDC reactors for the first time. Among the three type of anode electrodes investigated in this study, RSG electrode produced the highest power density and salt removal rate of 10.81 W/m 3 and 77.6%, respectively. Such a power density was 2.33 times higher than the MFC reactor due to the junction potential effect. In addition, adding the desalination function to the MFC reactor enhanced columbic efficiency from 21.8 to 31.4%. These results provided a proof-of-concept that the use of MDC instead of MFC would improve wastewater treatment efficiency and power generation, with an added benefit of water desalination. Furthermore, RSG can successfully be employed in an MDC or MFC, enhancing the bio-electricity generation and salt removal.

Slaughterhouse Wastewater Treatment by Combined Chemical Coagulation and Electrocoagulation Process

PubMed Central

Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein

2012-01-01

Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater. PMID:22768233

Slaughterhouse wastewater treatment by combined chemical coagulation and electrocoagulation process.

PubMed

Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein

2012-01-01

Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD(5) removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater.

Combining micelle-clay sorption to solar photo-Fenton processes for domestic wastewater treatment.

PubMed

Brienza, Monica; Nir, Shlomo; Plantard, Gael; Goetz, Vincent; Chiron, Serge

2018-06-08

A tertiary treatment of effluent from a biological domestic wastewater treatment plant was tested by combining filtration and solar photocatalysis. Adsorption was carried out by a sequence of two column filters, the first one filled with granular activated carbon (GAC) and the second one with granulated nano-composite of micelle-montmorillonite mixed with sand (20:100, w/w). The applied solar advanced oxidation process was homogeneous photo-Fenton photocatalysis using peroxymonosulfate (PMS) as oxidant agent. This combination of simple, robust, and low-cost technologies aimed to ensure water disinfection and emerging contaminants (ECs, mainly pharmaceuticals) removal. The filtration step showed good performances in removing dissolved organic matter and practically removing all bacteria such as Escherichia coli and Enterococcus faecalis from the secondary treated water. Solar advanced oxidation processes were efficient in elimination of trace levels of ECs. The final effluent presented an improved sanitary level with acceptable chemical and biological characteristics for irrigation.

Efficient removal of endosulfan from aqueous solution by UV-C/peroxides: a comparative study.

PubMed

Shah, Noor S; He, Xuexiang; Khan, Hasan M; Khan, Javed Ali; O'Shea, Kevin E; Boccelli, Dominic L; Dionysiou, Dionysios D

2013-12-15

This study explored the efficiency of UV-C-based advanced oxidation processes (AOPs), i.e., UV/S2O8(2-), UV/HSO5(-), and UV/H2O2 for the degradation of endosulfan, an organochlorine insecticide and an emerging water pollutant. A significant removal, 91%, 86%, and 64%, of endosulfan, at an initial concentration of 2.45 μM and UV fluence of 480 mJ/cm(2), was achieved by UV/S2O8(2-), UV/HSO5(-), and UV/H2O2 processes, respectively, at a [peroxide]0/[endosulfan]0 molar ratio of 20. The efficiency of these processes was, however, inhibited in the presence of radical scavengers, such as alcohols (e.g., tertiary butyl alcohol and isopropyl alcohol) and natural organic matter (NOM). The inhibition was also influenced by common inorganic anions in the order of nitrite > bicarbonate > chloride > nitrate ≈ sulfate. The observed pseudo-first-order rate constant decreased while the degradation rate increased with increasing initial concentration of the target contaminant. The degradation mechanism of endosulfan by the AOPs was evaluated revealing the main by-product as endosulfan ether. Results of this study suggest that UV-C-based AOPs are potential methods for the removal of pesticides, such as endosulfan and its by-products, from contaminated water. Copyright © 2013 Elsevier B.V. All rights reserved.

Spectroscopic characterization of dissolved organic matter in coking wastewater during bio-treatment: full-scale plant study.

PubMed

Xu, Ronghua; Ou, Huase; Yu, Xubiao; He, Runsheng; Lin, Chong; Wei, Chaohai

2015-01-01

This paper taking a full-scale coking wastewater (CWW) treatment plant as a case study aimed to characterize removal behaviors of dissolved organic matter (DOM) by UV spectra and fluorescence excitation-emission matrix-parallel factor analysis (PARAFAC), and investigate the correlations between spectroscopic indices and water quality parameters. Efficient removal rates of chemical oxygen demand (COD), dissolved organic carbon (DOC) and total nitrogen (TN) after the bio-treatment were 91.3%, 87.3% and 69.1%, respectively. UV270 was proven to be a stable UV absorption peak of CWW that could reflect the mixture of phenols, heterocyclics, polynuclear aromatic hydrocarbons and their derivatives. Molecular weight and aromaticity were increased, and also the content of polar functional groups was greatly reduced after bio-treatment. Three fluorescent components were identified by PARAFAC: C1 (tyrosine-like), C2 (tryptophan-like) and C3 (humic-like). The removal rate of protein-like was higher than that of humic-like and C1 was identified as biodegradable substance. Correlation analysis showed UV270 had an excellent correlation with COD (r=0.921, n=60, P<0.01) and DOC (r=0.959, n=60, P<0.01) and significant correlation (r=0.875, n=60, P<0.01) was also found between C2 and TN. Therefore, spectroscopic characterization could provide novel insights into removal behaviors of DOM and potential to monitor water quality real-time during CWW bio-treatment.

Escherichia coli Attenuation by Fe Electrocoagulation in Synthetic Bengal Groundwater: Effect of pH and Natural Organic Matter.

PubMed

Delaire, Caroline; van Genuchten, Case M; Nelson, Kara L; Amrose, Susan E; Gadgil, Ashok J

2015-08-18

Technologies addressing both arsenic and microbial contamination of Bengal groundwater are needed. Fe electrocoagulation (Fe-EC), a simple process relying on the dissolution of an Fe(0) anode to produce Fe(III) precipitates, has been shown to efficiently remove arsenic from groundwater at low cost. We investigated Escherichia coli (E. coli) attenuation by Fe-EC in synthetic Bengal groundwater as a function of Fe dosage rate, total Fe dosed, pH, and presence of natural organic matter (NOM). A 2.5 mM Fe dosage simultaneously achieved over 4-log E. coli attenuation and arsenic removal from 450 to below 10 μg/L. E. coli reduction was significantly enhanced at pH 6.6 compared to pH 7.5, which we linked to the decreased rate of Fe(II) oxidation at lower pH. 3 mg/L-C of NOM (Suwanee River fulvic acid) did not significantly affect E. coli attenuation. Live-dead staining and comparisons of Fe-EC with chemical coagulation controls showed that the primary mechanism of E. coli attenuation is physical removal with Fe(III) precipitates, with inactivation likely contributing as well at lower pH. Transmission electron microscopy showed that EC precipitates adhere to and bridge individual E. coli cells, resulting in large bacteria-Fe aggregates that can be removed by gravitational settling. Our results point to the promising ability of Fe-EC to treat arsenic and bacterial contamination simultaneously at low cost.

Apparatus and method for improving electrostatic precipitator performance by plasma reactor conversion of SO.sub.2 to SO.sub.3

DOEpatents

Huang, Hann-Sheng; Gorski, Anthony J.

1999-01-01

An apparatus and process that utilize a low temperature nonequilibrium plasma reactor, for improving the particulate removal efficiency of an electrostatic precipitator (ESP) are disclosed. A portion of the flue gas, that contains a low level of SO.sub.2 O.sub.2 H.sub.2 O, and particulate matter, is passed through a low temperature plasma reactor, which defines a plasma volume, thereby oxidizing a portion of the SO.sub.2 present in the flue gas into SO.sub.3. An SO.sub.2 rich flue gas is thereby generated. The SO.sub.3 rich flue gas is then returned to the primary flow of the flue gas in the exhaust treatment system prior to the ESP. This allows the SO.sub.3 to react with water to form H.sub.2 SO.sub.4 that is in turn is absorbed by fly ash in the gas stream in order to improve the removal efficiency of the EPS.

Poultry slaughterhouse wastewater treatment plant for high quality effluent.

PubMed

Del Nery, V; Damianovic, M H Z; Moura, R B; Pozzi, E; Pires, E C; Foresti, E

2016-01-01

This paper assesses a wastewater treatment plant (WWTP) regarding the technology used, as well as organic matter and nutrient removal efficiencies aiming to optimize the treatment processes involved and wastewater reclamation. The WWTP consists of a dissolved air flotation (DAF) system, an upflow anaerobic sludge blanket (UASB) reactor, an aerated-facultative pond (AFP) and a chemical-DAF system. The removal efficiencies of chemical oxygen demand (COD) (97.9 ± 1.0%), biochemical oxygen demand (BOD) (98.6 ± 1.0%) and oil and grease (O&G) (91.1 ± 5.2%) at the WWTP, the nitrogen concentration of 17 ± 11 mg N-NH3 and phosphorus concentration of 1.34 ± 0.93 mg PO4(-3)/L in the final effluent indicate that the processes used are suitable to comply with discharge standards in water bodies. Nitrification and denitrification tests conducted using biomass collected at three AFP points indicated that nitrification and denitrification could take place in the pond.

A pilot plant study using conventional and advanced water treatment processes: Evaluating removal efficiency of indicator compounds representative of pharmaceuticals and personal care products.

PubMed

Zhang, Shuangyi; Gitungo, Stephen; Axe, Lisa; Dyksen, John E; Raczko, Robert F

2016-11-15

With widespread occurrence of pharmaceuticals and personal care products (PPCPs) in the water cycle, their presence in source water has led to the need to better understand their treatability and removal efficiency in treatment processes. Fifteen indicator compounds were identified to represent the large number of PPCPs reported worldwide. Criteria applied to determine the indicator compounds included PPCPs widely used, observed at great frequency in aqueous systems, resistant to treatment, persistent in the environment, and representative of classes of organics. Through a pilot plant investigation to understand the optimal combination of unit process for treating PPCPs, 12 treatment trains with their additive and synergistic contributions were investigated; processes included dissolved air flotation (DAF), pre- and intermediate-ozonation with and without H 2 O 2 , intermediate chlorination, dual media filtration, granular activated carbon (GAC), and UV/H 2 O 2 . Treatment trains that achieved the greatest removals involved 1. DAF followed by intermediate ozonation, dual media filtration, and virgin GAC; 2. pre-ozonation followed by DAF, dual media filtration, and virgin GAC; and, 3. DAF (with either pre- or intermediate oxidation) followed by dual media filtration and UV/H 2 O 2 . Results revealed significant removal efficiencies for virgin GAC (preceded by DAF and intermediate ozonation) and UV/H 2 O 2 with an intensity of 700 mJ/cm 2 , where more than 12 of the compounds were removed by greater than 90%. Reduced PPCP removals were observed with virgin GAC preceded by pre-ozonation and DAF. Intermediate ozonation was more effective than using pre-ozonation, demonstrating the importance of this process targeting PPCPs after treatment of natural organic matter. Removal efficiencies of indicator compounds through ozonation were found to be a function of the O 3 rate constants (k O3 ). For compounds with low O 3 rate constants (k O3  < 10 M -1 s -1 ), H 2 O 2 addition in the O 3 reactor was required. Of the 15 indicator compounds, tri(2-chloroethyl) phosphate (TCEP) and cotinine were observed to be the most recalcitrant. Although UV/H 2 O 2 with elevated intensity (700 mJ/cm 2 ) was effective for PPCP removals, energy requirements far exceed intensities applied for disinfection. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Treatment effect of biological filtration and vegetable floating-bed combined system on greenhouse turtle breeding wastewater].

PubMed

Chen, Chong-Jun; Zhang, Rui; Xiang, Kun; Wu, Wei-Xiang

2014-08-01

Unorganized discharge of greenhouse turtle breeding wastewater has brought several negative influences on the ecological environment in the rural area of Yangtze River Delta. Biological filtration and vegetable floating-bed combined system is a potential ecological method for greenhouse turtle breeding wastewater treatment. In order to explore the feasibility of this system and evaluate the contribution of vegetable uptake of nitrogen (N) and phosphorus (P) in treating greenhouse turtle breeding wastewater, three types of vegetables, including Ipomoea aquatica, lettuce and celery were selected in this study. Results showed the combined system had a high capacity in simultaneous removal of organic matter, N and P. The removal efficiencies of COD, NH4(+)-N, TN and TP from the wastewater reached up to 93.2%-95.6%, 97.2%-99.6%, 73.9%-93.1% and 74.9%-90.0%, respectively. System with I. aquatica had the highest efficiencies in N and P removal, followed by lettuce and celery. However, plant uptake was not the primary pathway for TN arid TP removal in the combined system. The vegetable uptake of N and P accounted for only 9.1%-25.0% of TN and TP removal from the wastewater while the effect of microorganisms would be dominant for N and P removal. In addition, the highest amounts of N and P uptake in I. aquatica were closely related with the biomass of plant. Results from the study indicated that the biological filtration and vegetable floating-bed combined system was an effective approach to treating greenhouse turtle breeding wastewater in China.

Presence of Fe-Al binary oxide adsorbent cake layer in ceramic membrane filtration and their impact for removal of HA and BSA.

PubMed

Kim, Kyung-Jo; Jang, Am

2018-04-01

To enhance the removal of natural organic matter (NOM) in ceramic (Ce) membrane filtration, an iron-aluminum binary oxide (FAO) was applied to the ceramic membrane surface as the adsorbent cake layer, and it was compared with heated aluminum oxide (HAO) for the evaluation of the control of NOM. Both the HAO and FAO adsorbent cake layers efficiently removed the NOM regardless of NOM's hydrophobic/hydrophilic characteristics, and the dissolved organic carbon (DOC) removal in NOM for FAO was 1-1.12 times greater than that for HAO, which means FAO was more efficient in the removal of DOC in NOM. FAO (0.03 μm), which is smaller in size than HAO (0.4 μm), had greater flux reduction than HAO. The flux reduction increased as the filtration proceeded because most of the organic foulants (colloid/particles and soluble NOM) were captured by the adsorbent cake layer, which caused fouling between the membrane surface and the adsorbent cake layer. However, no chemically irreversible fouling was observed on the Ce membrane at the end of the FAO adsorbent cake layer filtration. This means that a stable adsorbent cake layer by FAO formed on the Ce membrane, and that the reduced pure water flux of the Ce membrane, resulting from the NOM fouling, can easily be recovered through physicochemical cleaning. Copyright © 2018 Elsevier Ltd. All rights reserved.

Aerosol removal due to precipitation and wind forcings in Milan urban area

NASA Astrophysics Data System (ADS)

Cugerone, Katia; De Michele, Carlo; Ghezzi, Antonio; Gianelle, Vorne

2018-01-01

Air pollution represents a critical issue in Milan urban area (Northern Italy). Here, the levels of fine particles increase, overcoming the legal limits, mostly in wintertime, due to favourable calm weather conditions and large heating and vehicular traffic emissions. The main goal of this work is to quantify the aerosol removal effect due to precipitation at the ground. At first, the scavenging coefficients have been calculated for aerosol particles with diameter between 0.25 and 3 μm. The average values of this coefficient vary between 2 ×10-5 and 5 ×10-5 s-1. Then, the aerosol removal induced separately by precipitation and wind have been compared through the introduction of a removal index. As a matter of fact, while precipitation leads to a proper wet scavenging of the particles from the atmosphere, high wind speeds cause enhanced particle dispersion and dilution, that locally bring to a tangible decrease of aerosol particles' number. The removal triggered by these two forcings showed comparable average values, but different trends. The removal efficiency of precipitation lightly increases with the increase of particle diameters and vice versa happens with strong winds.

Investigation of organic nitrogen and carbon removal in the aerobic digestion of various sludges.

PubMed

Genç, Nevim; Yonsel, Sems; Dağaşan, Levent; Onar, A N

2002-11-01

Nitrification and carbon removal are investigated in aerobic batch digestion of various sludges. The experiments are carried out with activated sludge (Test 1) and with a mixture of activated and primary settling sludge (Test 2). The nitrification rate was monitored, measuring the NO2- concentration. At the 3rd day of the digestion 40.7 mgNO2-N/l and 3.89 mgNO2-N/l were found in Tests 1 and 2 respectively. In a digestion process, the degradation of biomass indicates the beginning of the endogenous phase. Our measure for biomass content of the sludge was protein analysis. In Test 1, the first day values of 50.93 mgTOC/ g(dry) matter/day and 138.53 mg(protein)-C/g(dry) matter/day for specific TOC and protein-C removal rates showed, that the digestion process began in the endogenous phase. For Test 2, since the endogenous phase began after removal of raw organic matter in primary settling sludge, specific TOC and protein-C removal rates were observed to be 60.12 mgTOC/g(dry) matter/day and 26.72 mg(protein-C/g(dry)matter/day, respectively.

Characterization of ambient and extracted PM2.5 collected on filters for toxicology applications

PubMed Central

Roper, Courtney; Chubb, Lauren G.; Cambal, Leah; Tunno, Brett; Clougherty, Jane E.; Mischler, Steven E.

2016-01-01

Research on the health effects of fine particulate matter (PM2.5) frequently disregards the differences in particle composition between that measured on an ambient filter versus that measured in the corresponding extraction solution used for toxicological testing. This study presents a novel method for characterizing the differences, in metallic and organic species, between the ambient samples and the corresponding extracted solutions through characterization of extracted PM2.5 suspended on filters. Removal efficiency was found to be 98.0 ± 1.4% when measured using pre- and post-removal filter weights, however, this efficiency was significantly reduced to 80.2 ± 0.8% when measured based on particle mass in the extraction solution. Furthermore, only 47.2 ± 22.3% of metals and 24.8 ± 14.5% of organics measured on the ambient filter were found in the extraction solution. Individual metallic and organic components were extracted with varying efficiency, with many organics being lost entirely during extraction. Finally, extraction efficiencies of specific PM2.5 components were inversely correlated with total mass. This study details a method to assess compositional alterations resulting from extraction of PM2.5 from filters, emphasizing the need for standardized procedures that maintain compositional integrity of ambient samples for use in toxicology studies of PM2.5. PMID:26446919

Removal of 2-ClBP from soil-water system using activated carbon supported nanoscale zerovalent iron.

PubMed

Zhang, Wei; Yu, Tian; Han, Xiaolin; Ying, Weichi

2016-09-01

We explored the feasibility and removal mechanism of removing 2-chlorobiphenyl (2-ClBP) from soil-water system using granular activated carbon (GAC) impregnated with nanoscale zerovalent iron (reactive activated carbon or RAC). The RAC samples were successfully synthesized by the liquid precipitation method. The mesoporous GAC based RAC with low iron content (1.32%) exhibited higher 2-ClBP removal efficiency (54.6%) in the water phase. The result of Langmuir-Hinshelwood kinetic model implied that the different molecular structures between 2-ClBP and trichloroethylene (TCE) resulted in more difference in dechlorination reaction rates on RAC than adsorption capacities. Compared to removing 2-ClBP in the water phase, RAC removed the 2-ClBP more slowly in the soil phase due to the significant external mass transfer resistance. However, in the soil phase, a better removal capacity of RAC was observed than its base GAC because the chemical dechlorination played a more important role in total removal process for 2-ClBP. This important result verified the effectiveness of RAC for removing 2-ClBP in the soil phase. Although reducing the total RAC removal rate of 2-ClBP, soil organic matter (SOM), especially the soft carbon, also served as an electron transfer medium to promote the dechlorination of 2-ClBP in the long term. Copyright © 2016. Published by Elsevier B.V.

Collection of ultrafine diesel particulate matter (DPM) in cylindrical single-stage wet electrostatic precipitators.

PubMed

Saiyasitpanich, Phirun; Keener, Tim C; Lu, Mingming; Khang, Soon-Jai; Evans, Douglas E

2006-12-15

Long-term exposures to diesel particulate matter (DPM) emissions are linked to increasing adverse human health effects due to the potential association of DPM with carcinogenicity. Current diesel vehicular particulate emission regulations are based solely upon total mass concentration, albeit it is the submicrometer particles that are highly respirable and the most detrimental to human health. In this study, experiments were performed with a tubular single-stage wet electrostatic precipitator (wESP) to evaluate its performance for the removal of number-based DPM emissions. A nonroad diesel generator utilizing a low sulfur diesel fuel (500 ppmw) operating under varying load conditions was used as a stationary DPM emission source. An electrical low-pressure impactor (ELPI) was used to quantify the number concentration distributions of diesel particles in the diluted exhaust gas at each tested condition. The wESP was evaluated with respect to different operational control parameters such as applied voltage, gas residence time, etc., to determine their effect on overall collection efficiency, as well as particle size dependent collection efficiency. The results show that the total DPM number concentrations in the untreated diesel exhaust are in the magnitude of approximately108/cm(3) at all engine loads with the particle diameter modes between 20 and 40 nm. The measured collection efficiency of the wESP operating at 70 kV based on total particle numbers was 86% at 0 kW engine load and the efficiency decreased to 67% at 75 kW due to a decrease in gas residence time and an increase in particle concentrations. At a constant wESP voltage of 70 kV and at 75 kW engine load, the variation of gas residence time within the wESP from approximately 0.1 to approximately 0.4 s led to a substantial increase in the collection efficiency from 67% to 96%. In addition, collection efficiency was found to be directly related to the applied voltage, with increasing collection efficiency measured for increases in applied voltage. The collection efficiency based on particle size had a minimum for sizes between 20 and 50 nm, but at optimal wESP operating conditions it was possible to remove over 90% of all particle sizes. A comparison of measured and calculated collection efficiencies reveals that the measured values are significantly higher than the predicted values based on the well-known Deutsch equation.

Effects of dissolved organic matters (DOMs) on membrane fouling in anaerobic ceramic membrane bioreactors (AnCMBRs) treating domestic wastewater.

PubMed

Yue, Xiaodi; Koh, Yoong Keat Kelvin; Ng, How Yong

2015-12-01

Anaerobic membrane bioreactors (AnMBRs) have been regarded as a potential solution to achieve energy neutrality in the future wastewater treatment plants. Coupling ceramic membranes into AnMBRs offers great potential as ceramic membranes are resistant to corrosive chemicals such as cleaning reagents and harsh environmental conditions such as high temperature. In this study, ceramic membranes with pore sizes of 80, 200 and 300 nm were individually mounted in three anaerobic ceramic membrane bioreactors (AnCMBRs) treating real domestic wastewater to examine the treatment efficiencies and to elucidate the effects of dissolved organic matters (DOMs) on fouling behaviours. The average overall chemical oxygen demands (COD) removal efficiencies could reach around 86-88%. Although CH4 productions were around 0.3 L/g CODutilised, about 67% of CH4 generated was dissolved in the liquid phase and lost in the permeate. When filtering mixed liquor of similar properties, smaller pore-sized membranes fouled slower in long-term operations due to lower occurrence of pore blockages. However, total organic removal efficiencies could not explain the fouling behaviours. Liquid chromatography-organic carbon detection, fluorescence spectrophotometer and high performance liquid chromatography coupled with fluorescence and ultra-violet detectors were used to analyse the DOMs in detail. The major foulants were identified to be biopolymers that were produced in microbial activities. One of the main components of biopolymers--proteins--led to different fouling behaviours. It is postulated that the proteins could pass through porous cake layers to create pore blockages in membranes. Hence, concentrations of the DOMs in the soluble fraction of mixed liquor (SML) could not predict membrane fouling because different components in the DOMs might have different interactions with membranes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of various activated carbons for air cleaning - Towards design of immune and sustainable buildings

NASA Astrophysics Data System (ADS)

Haghighat, Fariborz; Lee, Chang-Seo; Pant, Bhuvan; Bolourani, Golnoush; Lakdawala, Ness; Bastani, Arash

There are increased demands for security, sustainability and indoor air quality in today's building design, construction, operation and maintenance. Installation of air cleaning systems can improve the indoor air quality by reducing the air pollution levels, and enhance the building security against sudden release of chemical and/or biological agents. At the same time, air cleaning techniques may reduce the building energy consumption by reducing the outdoor air supply rate, hence lowering the needs for conditioning of outdoor air. While the air filtration of particulate matter is well standardized, the standards against which the performance of air cleaning for gaseous contaminants is measured or classified are still under development. This study examined the performance of various granular activated carbons (GACs) for the removal of volatile organic compounds (VOCs) from mechanically ventilated buildings. Eight different GACs (three virgin and five impregnated) were tested against toluene using a dynamic test system. The virgin GACs showed better performance than impregnated ones, the percentage and the type of impregnation affected the removal efficiencies. Tests were also conducted with selected GACs against toluene, cyclohexane and ethyl acetate at relative humidity (RH) values of 30%, 50% and 70%. The effect of humidity was dependant on the VOC used. Both for toluene and cyclohexane, the removal efficiency decreased as RH increased. However, higher humidity showed a positive impact on the removal of ethyl acetate.

Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

PubMed

Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

2017-01-15

Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of disinfection by-products from contaminated water using a synthetic goethite catalyst via catalytic ozonation and a biofiltration system.

PubMed

Wang, Yu-Hsiang; Chen, Kuan-Chung

2014-09-10

The effects of synthetic goethite (α-FeOOH) used as the catalyst in catalytic ozonation for the degradation of disinfection by-product (DBP) precursors are investigated. A biofiltration column applied following the catalytic ozonation process is used to evaluate the efficiency of removing DBP precursors via biotreatment. Ozone can rapidly react with aromatic compounds and oxidize organic compounds, resulting in a decrease in the fluorescence intensity of dissolved organic matter (DOM). In addition, catalytic ozonation can break down large organic molecules, which causes a blue shift in the emission-excitation matrix spectra. Water treated with catalytic ozonation is composed of low-molecular structures, including soluble microbial products (SMPs) and other aromatic proteins (APs). The DOM in SMPs and APs is removed by subsequent biofiltration. Catalytic ozonation has a higher removal efficiency for dissolved organic carbon and higher ultraviolet absorbance at 254 nm compared to those of ozonation without a catalyst. The use of catalytic ozonation and subsequent biofiltration leads to a lower DBP formation potential during chlorination compared to that obtained using ozonation and catalytic ozonation alone. Regarding DBP species during chlorination, the bromine incorporation factor (BIF) of trihalomethanes and haloacetic acids increases with increasing catalyst dosage in catalytic ozonation. Moreover, the highest BIF is obtained for catalytic ozonation and subsequent biofiltration.

Removal of Disinfection By-Products from Contaminated Water Using a Synthetic Goethite Catalyst via Catalytic Ozonation and a Biofiltration System·

PubMed Central

Wang, Yu-Hsiang; Chen, Kuan-Chung

2014-01-01

The effects of synthetic goethite (α-FeOOH) used as the catalyst in catalytic ozonation for the degradation of disinfection by-product (DBP) precursors are investigated. A biofiltration column applied following the catalytic ozonation process is used to evaluate the efficiency of removing DBP precursors via biotreatment. Ozone can rapidly react with aromatic compounds and oxidize organic compounds, resulting in a decrease in the fluorescence intensity of dissolved organic matter (DOM). In addition, catalytic ozonation can break down large organic molecules, which causes a blue shift in the emission-excitation matrix spectra. Water treated with catalytic ozonation is composed of low-molecular structures, including soluble microbial products (SMPs) and other aromatic proteins (APs). The DOM in SMPs and APs is removed by subsequent biofiltration. Catalytic ozonation has a higher removal efficiency for dissolved organic carbon and higher ultraviolet absorbance at 254 nm compared to those of ozonation without a catalyst. The use of catalytic ozonation and subsequent biofiltration leads to a lower DBP formation potential during chlorination compared to that obtained using ozonation and catalytic ozonation alone. Regarding DBP species during chlorination, the bromine incorporation factor (BIF) of trihalomethanes and haloacetic acids increases with increasing catalyst dosage in catalytic ozonation. Moreover, the highest BIF is obtained for catalytic ozonation and subsequent biofiltration. PMID:25211774

Investigations on humic acid removal from water using surfactant-modified zeolite as adsorbent in a fixed-bed reactor

NASA Astrophysics Data System (ADS)

Elsheikh, Awad F.; Ahmad, Umi Kalthom; Ramli, Zainab

2017-10-01

Natural organic matter (NOM) is ubiquitous in aquatic environments and has recently become an issue of worldwide concern in drinking water treatment. The major component of NOM is humic acids (HA). In this study, a natural zeolite (mordenite) was modified employing hexadecyltrimethylammonium bromide (HDTMA) to enhance greater efficient sites for sorption of HA. The natural zeolite and surfactant-modified zeolite (SMZ) were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FT-IR), N2 Adsorption-desorption isotherms and BET-specific surface area, thermographic analysis, derivative thermographic analysis (TGA-DTA) and Field emission scanning electron microscopy (FESEM). A fixed-bed reactor was used for the removal of HA and the effects of different experimental parameters such as HDTMA loading levels, HA solution flow rate, solution pH and eluent concentration were investigated. The results indicated that the SMZ bed with HDTMA loading of 75% of external cation exchange capacity (ECEC) at a flow rate of 2 BV/h and pH of 10 showed the greatest enhanced removal efficiency of HA while ethanol solutions (25%v/v) with feed flow rate of 2 BV/h were sufficient for complete regeneration of SMZ and desorption of HA. Measurements of surface area of SMZ indicated that a monolayer formation of the surfactant at those conditions allowed the optimum removal of HA.

Partitioning of dissolved organic matter-bound mercury between a hydrophobic surface and polysulfide-rubber polymer.

PubMed

Kim, Eun-Ah; Luthy, Richard G

2011-11-01

This study investigated the role of dissolved organic matter on mercury partitioning between a hydrophobic surface (polyethylene, PE) and a reduced sulfur-rich surface (polysulfide rubber, PSR). Comparative sorption studies employed polyethylene and polyethylene coated with PSR for reactions with DOM-bound mercuric ions. These studies revealed that PSR enhanced the Hg-DOM removal from water when DOM was Suwannee River natural organic matter (NOM), fulvic acid (FA), or humic acid (HA), while the same amount of 1,3-propanedithiol-bound mercuric ion was removed by both PE and PSR-PE. The differences for Hg-DOM removal efficiencies between PE and PSR-PE varied depending on which DOM was bound to mercuric ion as suggested by the PE/water and PSR-PE/water partition coefficients for mercury. The surface concentrations of mercury on PE and PSR-PE with the same DOM measured by x-ray photoelectron spectroscopy were similar, which indicated the comparable amounts of immobilized mercury on PE and PSR-PE being exposed to the aqueous phase. With these observations, two major pathways for the immobilization reactions between PSR-PE and Hg-DOM were examined: 1) adsorption of Hg-DOM on PE by hydrophobic interactions between DOM and PE, and 2) addition reaction of Hg-DOM onto PSR by a complexation reaction between Hg and PSR. The percent contribution of each pathway was derived from a mass balance and the ratios among aqueous mercury, PE-bound Hg-DOM, and PSR-bound Hg-DOM concentrations. The results indicate strong binding of mercuric ion with both dissolved organic matter and PSR polymer. The FT-IR examination of Hg-preloaded-PSR-PEs after the reaction with DOM corroborated a strong interaction between mercuric ion and 1,3-propanedithiol compared to Hg-HA, Hg-FA, or Hg-NOM interactions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Partitioning of dissolved organic matter-bound mercury between a hydrophobic surface and polysulfide-rubber polymer

PubMed Central

Kim, Eun-Ah

2011-01-01

This study investigated the role of dissolved organic matter on mercury partitioning between a hydrophobic surface (polyethylene, PE) and a reduced sulfur-rich surface (polysulfide rubber, PSR). Comparative sorption studies employed polyethylene and polyethylene coated with PSR for reactions with DOM-bound mercuric ions. These studies revealed that PSR enhanced the Hg-DOM removal from water when DOM was Suwannee River natural organic matter (NOM), fulvic acid (FA), or humic acid (HA), while the same amount of 1,3-propanedithiol-bound mercuric ion was removed by both PE and PSR-PE. The differences for Hg-DOM removal efficiencies between PE and PSR-PE varied depending on which DOM was bound to mercuric ion as suggested by the PE/water and PSR-PE/water partition coefficients for mercury. The surface concentrations of mercury on PE and PSR-PE with the same DOM measured by x-ray – photoelectron spectroscopy were similar, which indicated the comparable amounts of immobilized mercury on PE and PSR-PE being exposed to the aqueous phase. With these observations, two major pathways for the immobilization reactions between PSR-PE and Hg- DOM were examined: 1) adsorption of Hg-DOM on PE by hydrophobic interactions between DOM and PE, and 2) addition reaction of Hg-DOM onto PSR by a complexation reaction between Hg and PSR. The percent contribution of each pathway was derived from a mass balance and the ratios among aqueous mercury, PE-bound Hg-DOM, and PSR-bound Hg-DOM concentrations. The results indicate strong binding of mercuric ion with both dissolved organic matter and PSR polymer. The FT-IR examination of Hg-preloaded-PSR-PEs after the reaction with DOM corroborated a strong interaction between mercuric ion and 1,3-propanedithiol compared to Hg-HA, Hg-FA, or Hg-NOM interactions. PMID:21872900

Lowering temperature to increase chemical oxidation efficiency: the effect of temperature on permanganate oxidation rates of five types of well defined organic matter, two natural soils, and three pure phase products.

PubMed

de Weert, J P A; Keijzer, T J S; van Gaans, P F M

2014-12-01

In situ chemical oxidation (ISCO) is a soil remediation technique to remove organic pollutants from soil and groundwater with oxidants, like KMnO4. However, also natural organic compounds in soils are being oxidized, which makes the technique less efficient. Laboratory experiments were performed to investigate the influence of temperature on this efficiency, through its effect on the relative oxidation rates - by permanganate - of natural organic compounds and organic pollutants at 16 and 15°C. Specific types of organic matter used were cellulose, oak wood, anthracite, reed - and forest peat, in addition to two natural soils. Dense Non-Aqueous Phase Liquid-tetrachloroethene (DNAPL-PCE), DNAPL trichloroethene (DNAPL-TCE) and a mixture of DNAPL-PCE, -TCE and -hexachlorobutadiene were tested as pollutants. Compared to 16°C, oxidation was slower at 5°C for the specific types of organic matter and the natural soils, with exception of anthracite, which was unreactive. The oxidation rate of DNAPL TCE was lower at 5°C too. However, at this temperature oxidation was fast, implying that no competitive loss to natural organic compounds will be expected in field applications by lowering temperature. Oxidation of DNAPL-PCE and PCE in the mixture proceeded at equal rates at both temperatures, due to the dissolution rate as limiting factor. These results show that applying permanganate ISCO to DNAPL contamination at lower temperatures will limit the oxidation of natural organic matter, without substantially affecting the oxidation rate of the contaminant. This will make such remediation more effective and sustainable in view of protecting natural soil quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stimulation of oxygen to bioanode for energy recovery from recalcitrant organic matter aniline in microbial fuel cells (MFCs).

PubMed

Cheng, Hao-Yi; Liang, Bin; Mu, Yang; Cui, Min-Hua; Li, Kun; Wu, Wei-Min; Wang, Ai-Jie

2015-09-15

The challenge of energy generation from biodegradation of recalcitrant organics in microbial fuel cells (MFCs) is mainly attributed to their persistence to degradation under anaerobic condition in anode chamber of MFCs. In this work, we demonstrated that electricity generation from aniline, a typical recalcitrant organic matter under anaerobic condition was remarkably facilitated by employing oxygen into bioanode of MFCs. By exposing bioanode to air, electrons of 47.2 ± 6.9 C were recovered with aniline removal efficiency of 91.2 ± 2.2% in 144 h. Limited oxygen supply (the anodic headspace was initially filled with air and then closed) resulted in the decrease of electrons recovery and aniline removal efficiency by 52.5 ± 9.4% and 74.2 ± 2.1%, respectively, and further decline by respective 64.3 ± 4.5% and 82.7 ± 1.0% occurred under anaerobic condition. Community analysis showed that anode biofilm was predominated by several aerobic aniline degrading bacteria (AADB) and anode-respiration bacteria (ARB), which likely cooperated with each other and finally featured the energy recovery from aniline. Cyclic voltammetry indicated that anodic bacteria transferred electrons to anode mainly through electron shuttle. This study provided a new sight to acquaint us with the positive role of oxygen in biodegradation of recalcitrant organics on anode as well as electricity generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pilot-Scale Demonstration of Pefi's Oxygenated Transportation Fuels Production Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Coal-cleaning processes have been utilized to increase the heating value of coal by extracting ash-forming minerals in the coal. These processes involve the crushing or grinding of raw coal followed by physical separation processes, taking advantage of the density difference between carbonaceous particles and mineral particles. In addition to the desired increase in the heating value of coal, a significant reduction of the sulfur content of the coal fed to a combustion unit is effected by the removal of pyrite and other sulfides found in the mineral matter. WRI is assisting PulseWave to develop an alternate, more efficient method ofmore » liberating and separating the undesirable mineral matter from the carbonaceous matter in coal. The approach is based on PulseWave's patented resonance disintegration technology that reduces that particle size of materials by application of destructive resonance, shock waves, and vortex generating forces. Illinois No.5 coal, a Wyodak coal, and a Pittsburgh No.8 coal were processed using the resonance disintegration apparatus then subjected to conventional density separations. Initial microscopic results indicate that up to 90% of the pyrite could be liberated from the coal in the machine, but limitations in the density separations reduced overall effectiveness of contaminant removal. Approximately 30-80% of the pyritic sulfur and 30-50% of the mercury was removed from the coal. The three coals (both with and without the pyritic phase separated out) were tested in WRI's 250,000 Btu/hr Combustion Test Facility, designed to replicate a coal-fired utility boiler. The flue gases were characterized for elemental, particle bound, and total mercury in addition to sulfur. The results indicated that pre-combustion cleaning could reduce a large fraction of the mercury emissions.« less

Advanced oxidation processes for the removal of natural organic matter from drinking water sources: A comprehensive review.

PubMed

Sillanpää, Mika; Ncibi, Mohamed Chaker; Matilainen, Anu

2018-02-15

Natural organic matter (NOM), a key component in aquatic environments, is a complex matrix of organic substances characterized by its fluctuating amounts in water and variable molecular and chemical properties, leading to various interaction schemes with the biogeosphere and hydrologic cycle. These factors, along with the increasing amounts of NOM in surface and ground waters, make the effort of removing naturally-occurring organics from drinking water supplies, and also from municipal wastewater effluents, a challenging task requiring the development of highly efficient and versatile water treatment technologies. Advanced oxidation processes (AOPs) received an increasing amount of attention from researchers around the world, especially during the last decade. The related processes were frequently reported to be among the most suitable water treatment technologies to remove NOM from drinking water supplies and mitigate the formation of disinfection by products (DBPs). Thus, the present work overviews recent research and development studies conducted on the application of AOPs to degrade NOM including UV and/or ozone-based applications, different Fenton processes and various heterogeneous catalytic and photocatalytic oxidative processes. Other non-conventional AOPs such as ultrasonication, ionizing radiation and plasma technologies were also reported. Furthermore, since AOPs are unlikely to achieve complete oxidation of NOM, integration schemes with other water treatment technologies were presented including membrane filtration, adsorption and others processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid removal of bacterial endotoxin and natural organic matter in water by dielectric barrier discharge plasma: Efficiency and toxicity assessment.

PubMed

Zhang, Can; Fang, Zhendong; Liu, Wenjun; Tian, Fang; Bai, Miao

2016-11-15

Low-temperature plasma was used to control bacteria, endotoxins and natural organic matter (NOM) in water by a dielectric barrier discharge (DBD) device. Results indicate that DBD plasma has an obvious inactivation effect on various bacteria in water. The degree of inactivation from difficult to easy is as follows: Bacillus subtilis>Escherichia coli>Staphylococcus aureus. Activated ultrapure water treated using DBD plasma exhibited a sustained sterilization effect, but this sterilization effect decreased gradually after 1h. The total-endotoxin (free-endotoxin and bound-endotoxin) released by Escherichia coli during inactivation, as well as artificially simulated endotoxin in a control solution, was significantly controlled by DBD plasma. Both the metabolites that appeared after inactivation of microorganisms by plasma treatment, and the NOM in filtration effluent of a water treatment plant were well removed by DBD plasma if the treatment duration was sufficiently long. However, the acute toxicity increased significantly, and persisted for at least 2h, indicating that some long-life active substances were generated during the DBD process. Therefore, the removal of bacteria, endotoxins or NOM does not mean a safe water is produced. It is also important to eliminate the toxicity and byproducts produced during water treatment for the continuous promotion and industrial application of DBD plasma. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimized Extraction Method To Remove Humic Acid Interferences from Soil Samples Prior to Microbial Proteome Measurements.

PubMed

Qian, Chen; Hettich, Robert L

2017-07-07

The microbial composition and their activities in soil environments play a critical role in organic matter transformation and nutrient cycling. Liquid chromatography coupled to high-performance mass spectrometry provides a powerful approach to characterize soil microbiomes; however, the limited microbial biomass and the presence of abundant interferences in soil samples present major challenges to proteome extraction and subsequent MS measurement. To this end, we have designed an experimental method to improve microbial proteome measurement by removing the soil-borne humic substances coextraction from soils. Our approach employs an in situ detergent-based microbial lysis/TCA precipitation coupled to an additional cleanup step involving acidified precipitation and filtering at the peptide level to remove most of the humic acid interferences prior to proteolytic peptide measurement. The novelty of this approach is an integration to exploit two different characteristics of humic acids: (1) Humic acids are insoluble in acidic solution but should not be removed at the protein level, as undesirable protein removal may also occur. Rather it is better to leave the humics acids in the samples until the peptide level, at which point the significant differential solubility of humic acids versus peptides at low pH can be exploited very efficiently. (2) Most of the humic acids have larger molecule weights than the peptides. Therefore, filtering a pH 2 to 3 peptide solution with a 10 kDa filter will remove most of the humic acids. This method is easily interfaced with normal proteolytic processing approaches and provides a reliable and straightforward protein extraction method that efficiently removes soil-borne humic substances without inducing proteome sample loss or biasing protein identification in mass spectrometry. In general, this humic acid removal step is universal and can be adopted by any workflow to effectively remove humic acids to avoid them negatively competing with peptides for binding with reversed-phase resin or ionization in the electrospray.

The influence of algal organic matter produced by Microcystis aeruginosa on coagulation-ultrafiltration treatment of natural organic matter.

PubMed

Xu, Jie; Zhao, Yanxia; Gao, Baoyu; Han, Songlin; Zhao, Qian; Liu, Xiaoli

2018-04-01

Cyanobacterial bloom causes the release of algal organic matter (AOM), which inevitably affects the treatment processes of natural organic matter (NOM). This study works on treating micro-polluted surface water (SW) by emerging coagulant, namely titanium sulfate (Ti(SO 4 ) 2 ), followed by Low Pressure Ultrafiltration (LPUF) technology. In particular, we explored the respective influence of extracellular organic matter (EOM) and intracellular organic matter (IOM) on synergetic EOM-NOM/IOM-NOM removal, functional mechanisms and subsequent filtration performance. Results show that the IOM inclusion in surface water body facilitated synergic IOM-NOM composite pollutants removal by Ti(SO 4 ) 2 , wherein loosely-aggregated flocs were produced, resulting in floc cake layer with rich porosity and permeability during LPUF. On the contrary, the surface water invaded by EOM pollutants increased Ti(SO 4 ) 2 coagulation burden, with substantially deteriorated both UV 254 -represented and dissolved organic matter (DOC) removal. Corresponded with the weak Ti(SO 4 ) 2 coagulation for EOM-NOM removal was the resultant serious membrane fouling during LPUF procedure, wherein dense cake layer was formed due to the compact structure of flocs. Although the IOM enhanced NOM removal with reduced Ti(SO 4 ) 2 dose and yielded mitigated membrane fouling, larger percentage of irreversible fouling was seen than NOM and EOM-NOM cases, which was most likely due to the substances with small molecular weight, such as microcystin, adhering in membrane pores. This research would provide theoretical basis for dose selection and process design during AOM-NOM water treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Method for removing particulate matter from a gas stream

DOEpatents

Postma, Arlin K.

1984-01-01

Particulate matter is removed from a stream of pressurized gas by directing the stream of gas upwardly through a bed of porous material, the porous bed being held in an open ended container and at least partially submerged in liquid. The passage of the gas through the porous bed sets up a circulation in the liquid which cleans the particulate matter from the bed.

Hydrodynamic cavitation in combination with the ozone, hydrogen peroxide and the UV-based advanced oxidation processes for the removal of natural organic matter from drinking water.

PubMed

Čehovin, Matej; Medic, Alojz; Scheideler, Jens; Mielcke, Jörg; Ried, Achim; Kompare, Boris; Žgajnar Gotvajn, Andreja

2017-07-01

Natural organic matter in drinking water is causing concern especially due to the formation of disinfection by-products (DBPs) by chlorine, as these are proven to have adverse health effects on consumers. In this research, humic acid was used as a source of dissolved organic carbon (DOC) in drinking water (up to 3mgL -1 ). The efficiency of DOC removal was studied by applying O 3 , H 2 O 2 /O 3 , H 2 O 2 /UV and O 3 /UV advanced oxidation processes (AOPs) alone and combined with hybrid hydrodynamic cavitation (HC), generated by an orifice plate, as this technology recently shows promising potential for the treatment of water, containing recalcitrant organic substances. It was observed that the combined treatment by HC could significantly affect the performance of the applied AOPs, with as little as 3-9 passes through the cavitation generators. For O 3 and H 2 O 2 dosages up to 2 and 4mgL -1 , respectively, and UV dosage up to 300mJcm -2 , HC enhanced DOC removal by 5-15% in all combinations, except for O 3 /UV AOPs. Overall, the potential benefits of HC for DOC removal were emphasized for low ratio between applied oxidants to DOC and high UV absorbance of the sample. Investigated DBPs formation potentials require special attention for H 2 O 2 /UV AOPs and combinations with HC. Copyright © 2017 Elsevier B.V. All rights reserved.

Tracking the behavior of different size fractions of dissolved organic matter in a full-scale advanced drinking water treatment plant.

PubMed

Quang, Viet Ly; Choi, Ilhwan; Hur, Jin

2015-11-01

In this study, five different dissolved organic matter (DOM) fractions, defined based on a size exclusion chromatography with simultaneous detection of organic carbon (OCD) and ultraviolet (UVD), were quantitatively tracked with a treatment train of coagulation/flocculation-sand filtration-ozonation-granular activated carbon (GAC) filtration in a full-scale advanced drinking water treatment plant (DWTP). Five DOM samples including raw water were taken after each treatment process in the DWTP every month over the period of three years. A higher abundance of biopolymer (BP) fraction was found in the raw water during spring and winter than in the other seasons, suggesting an influence of algal bloom and/or meltwater on DOM composition. The greater extent of removal was observed upon the coagulation/flocculation for high-molecular-weight fractions including BP and humic substances (HS) and aromatic moieties, while lower sized fractions were preferentially removed by the GAC filtration. Ozone treatment produced the fraction of low-molecular-weight neutrals probably resulting from the breakdown of double-bonded carbon structures by ozone oxidation. Coagulation/flocculation was the only process that revealed significant effects of influent DOM composition on the treatment efficiency, as revealed by a high correlation between the DOM removal rate and the relative abundance of HS for the raw water. Our study demonstrated that SEC-OCD-UVD was successful in monitoring size-based DOM composition for the advanced DWTP, providing an insight into optimizing the treatment options and the operational conditions for the removal of particular fractions within the bulk DOM.

Ten-year results from the long-term soil productivity study in aspen ecosystems of the northern Great Lakes region

Treesearch

Richard Voldseth; Brian J. Palik; John Elioff

2011-01-01

Impacts of organic matter removal and compaction on soil properties and productivity are reported from the first 10 years of the Long-Term Soil Productivity Study in Great Lakes aspen ecosystems. Organic matter removal treatments included main bole, total tree harvest, and total tree harvest with forest floor removal. Compaction treatments included minimal compaction,...

Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems.

PubMed

Macintosh, David L; Myatt, Theodore A; Ludwig, Jerry F; Baker, Brian J; Suh, Helen H; Spengler, John D

2008-11-01

A novel method for determining whole house particle removal and clean air delivery rates attributable to central and portable ventilation/air cleaning systems is described. The method is used to characterize total and air-cleaner-specific particle removal rates during operation of four in-duct air cleaners and two portable air-cleaning devices in a fully instrumented test home. Operation of in-duct and portable air cleaners typically increased particle removal rates over the baseline rates determined in the absence of operating a central fan or an indoor air cleaner. Removal rates of 0.3- to 0.5-microm particles ranged from 1.5 hr(-1) during operation of an in-duct, 5-in. pleated media filter to 7.2 hr(-1) for an in-duct electrostatic air cleaner in comparison to a baseline rate of 0 hr(-1) when the air handler was operating without a filter. Removal rates for total particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass concentrations were 0.5 hr(-1) under baseline conditions, 0.5 hr(-1) during operation of three portable ionic air cleaners, 1 hr(-1) for an in-duct 1-in. media filter, 2.4 hr(-1) for a single high-efficiency particle arrestance (HEPA) portable air cleaner, 4.6 hr(-1) for an in-duct 5-in. media filter, 4.7 hr(-1) during operation of five portable HEPA filters, 6.1 hr(-1) for a conventional in-duct electronic air cleaner, and 7.5 hr(-1) for a high efficiency in-duct electrostatic air cleaner. Corresponding whole house clean air delivery rates for PM2.5 attributable to the air cleaner independent of losses within the central ventilation system ranged from 2 m3/min for the conventional media filter to 32 m3/min for the high efficiency in-duct electrostatic device. Except for the portable ionic air cleaner, the devices considered here increased particle removal indoors over baseline deposition rates.

Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis.

PubMed

Wang, Hong-Cheng; Cheng, Hao-Yi; Wang, Shu-Sen; Cui, Dan; Han, Jing-Long; Hu, Ya-Ping; Su, Shi-Gang; Wang, Ai-Jie

2016-01-01

In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater. Copyright © 2015. Published by Elsevier B.V.

Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters

PubMed Central

Minegishi, Taeko; Allen, Joseph G.; McCarthy, John F.; Spengler, John D.; MacIntosh, David L.

2014-01-01

Objective Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. Methods We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used “each pass removal efficiency” applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Results Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. Conclusions The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients. PMID:24555523

Removal of basic dyes from aqueous solutions with a treated spent bleaching earth.

PubMed

Mana, Mohamed; Ouali, Mohand-Said; de Menorval, L C

2007-03-01

A spent bleaching earth from an edible oil refinery was treated by impregnation with a normal sodium hydroxide solution followed by mild thermal treatment (100 degrees C). The obtained material (TSBE) was washed, dried, and characterized by X-ray diffraction, FTIR, SEM, BET, and thermal analysis. The clay structure was not apparently affected by the treatment and the impregnated organic matter was quantitatively removed. We have investigated the comparative sorption of safranine and methylene blue on this material, the spent bleaching earth (SBE), and the virgin bleaching earth (VBE). The kinetic results fit the pseudo-second-order kinetic model and the Weber and Morris intraparticle diffusion model. The pH had no effect on the sorption efficiency. The sorption isotherms followed the Langmuir model for various sorbent concentrations with good values of the determination coefficient. A linear relationship was found between the calculated maximum removal capacity and the solid/solution ratio. A comparison between the results obtained with this material and those of the literature highlighted the low cost and the good removal capacity of treated spent bleaching earth.

Colloids removal from water resources using natural coagulant: Acacia auriculiformis

NASA Astrophysics Data System (ADS)

Abdullah, M.; Roslan, A.; Kamarulzaman, M. F. H.; Erat, M. M.

2017-09-01

All waters, especially surface waters contain dissolved, suspended particles and/or inorganic matter, as well as several biological organisms, such as bacteria, algae or viruses. This material must be removed because it can affect the water quality that can cause turbidity and colour. The objective of this study is to develop water treatment process from Seri Alam (Johor, Malaysia) lake water resources by using natural coagulant Acacia auriculiformis pods through a jar test experiment. Jar test is designed to show the effectiveness of the water treatment. This process is a laboratory procedure that will simulate coagulation/flocculation with several parameters selected namely contact time, coagulant dosage and agitation speed. The most optimum percentage of colloids removal for each parameter is determined at 0.2 g, 90 min and 80 rpm. FESEM (Field-emission Scanning Electron Microscope) observed the small structures of final floc particles for optimum parameter in this study to show that the colloids coagulated the coagulant. All result showed that the Acacia auriculiformis pods can be a very efficient coagulant in removing colloids from water.

Mesquite wood chips (Prosopis) as filter media in a biofilter system for municipal wastewater treatment.

PubMed

Sosa-Hernández, D B; Vigueras-Cortés, J M; Garzón-Zúñiga, M A

2016-01-01

The biofiltration system over organic bed (BFOB) uses organic filter material (OFM) to treat municipal wastewater (MWW). This study evaluated the performance of a BFOB system employing mesquite wood chips (Prosopis) as OFM. It also evaluated the effect of hydraulic loading rates (HLRs) in order to achieve the operational parameters required to remove organic matter, suspended material, and pathogens, thus meeting Mexican and US regulations for reuse in irrigation. Two biofilters (BFs) connected in series were installed; the first one aerated (0.62 m(3)air m(-2)h(-1)) and the second one unaerated. The source of MWW was a treatment plant located in Durango, Mexico. For 200 days, three HLRs (0.54, 1.07, and 1.34 m(3)m(-2)d(-1)) were tested. The maximum HLR at which the system showed a high removal efficiency of pollutants and met regulatory standards for reuse in irrigation was 1.07 m(3)m(-2)d(-1), achieving removal efficiencies of biochemical oxygen demand (BOD5) 92%, chemical oxygen demand (COD) 78%, total suspended solids (TSS) 95%, and four log units of fecal coliforms. Electrical conductivity in the effluent ensures that it would not cause soil salinity. Therefore, mesquite wood chips can be considered an innovative material suitable as OFM for BFs treating wastewaters.

Removal of organic micropollutants from drinking water by a novel electro-Fenton filter: Pilot-scale studies.

PubMed

Plakas, Konstantinos V; Sklari, Stella D; Yiankakis, Dimitrios A; Sideropoulos, Georgios Th; Zaspalis, Vassilis T; Karabelas, Anastasios J

2016-03-15

To assess the performance of a novel 'filter'-type electro-Fenton (EF) device, results are reported from pilot-scale studies of continuous water treatment, to degrade diclofenac (DCF), a typical organic micro-pollutant, with no addition of oxidants. The novel 'filter' consisted of three pairs of anode/cathode electrodes made of carbon felt, with cathodes impregnated with iron nanoparticles (γ-Fe2O3/F3O4 oxides). The best 'filter' performance was obtained at applied potential of 2 V and low water superficial velocities (∼0.09 cm/s), i.e., the mineralization current efficiency (MCE) was >20%, during continuous steady state treatment of tap water with low DCF concentrations (16 μg/L). The EF 'filter' exhibited satisfactory stability regarding both electrode integrity (no iron leaching) and removal efficiency, even after multiple filtration/oxidation treatment cycles, achieving (under steady conditions) DCF and TOC removal 85% and 36%, respectively. This performance is considered satisfactory because the EF process took place under rather unfavorable conditions, such as neutral pH, low dissolved O2 concentration, low electrical conductivity, and presence of natural organic matter and inorganic ions in tap water. Ongoing R&D is aimed at 'filter' development and optimization for practical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of powdered activated carbon addition on water quality, sludge properties, and microbial characteristics in the biological treatment of commingled industrial wastewater.

PubMed

Hu, Qing-Yuan; Li, Meng; Wang, Can; Ji, Min

2015-09-15

A powdered activated carbon-activated sludge (PAC-AS) system, a traditional activated sludge (AS) system, and a powdered activated carbon (PAC) system were operated to examine the insights into the influence of PAC addition on biological treatment. The average COD removal efficiencies of the PAC-AS system (39%) were nearly double that of the AS system (20%). Compared with the average efficiencies of the PAC system (7%), COD removal by biodegradation in the PAC-AS system was remarkably higher than that in the AS system. The analysis of the influence of PAC on water quality and sludge properties showed that PAC facilitated the removal of hydrophobic matter and metabolic acidic products, and also enhanced the biomass accumulation, sludge settleability, and specific oxygen uptake rate inside the biological system. The microbial community structures in the PAC-AS and AS systems were monitored. The results showed that the average well color development in the PAC-AS system was higher than that in the AS system. The utilization of various substrates by microorganisms in the two systems did not differ. The dissimilarity index was far less than one; thus, showing that the microbial community structures of the two systems were the same. Copyright © 2015 Elsevier B.V. All rights reserved.

Composting plant leachate treatment by a pilot-scale, three-stage, horizontal flow constructed wetland in central Iran.

PubMed

Bakhshoodeh, Reza; Alavi, Nadali; Paydary, Pooya

2017-10-01

Handling and treatment of composting leachate is difficult and poses major burdens on composting facilities. The main goal of this study was to evaluate usage of a three-stage, constructed wetland to treat leachate produced in Isfahan composting facility. A pilot-scale, three-stage, subsurface, horizontal flow constructed wetland, planted with vetiver with a flow rate of 24 L/day and a 15-day hydraulic retention time, was used. Removal of organic matter, ammonia, nitrate, total nitrogen, suspended solids, and several heavy metals from Isfahan composting facility leachate was monitored over a 3-month period. Constructed wetland system was capable of efficiently removing BOD 5 (87.3%), COD (74.5%), ammonia (91.5%), nitrate (87.9%), total nitrogen (87.8%), total suspended solids (85.5%), and heavy metals (ranging from 70 to 90%) from the composting leachate. High contaminant removal efficiencies were achieved, but effluent still failed to meet Iranian standards for treated wastewater. This study shows that although a three-stage horizontal flow constructed wetland planted with vetiver cannot be used alone to treat Isfahan composting facility leachate, but it has the potential to be used as a leachate pre-treatment step, along with another complementary method.

Solar photocatalytic ozonation of a mixture of pharmaceutical compounds in water.

PubMed

Márquez, Gracia; Rodríguez, Eva M; Beltrán, Fernando J; Álvarez, Pedro M

2014-10-01

Aqueous solutions of mixtures of four pharmaceutical compounds (atenolol, hydrochlorothiazide, ofloxacin and trimethoprim) both in Milli-Q ultrapure water and in a secondary effluent from a municipal wastewater treatment plant have been treated at pH 7 by different oxidation methods, such as conventional ozonation, photolytic ozonation, TiO2 catalytic ozonation, TiO2 photocatalytic oxidation and TiO2 photocatalytic ozonation. Experiments were carried out using a solar compound parabolic concentrator. The performance results have been compared in terms of removal of emerging contaminants (ECs), generation rate of phenolic intermediates, organic matter mineralization, ecotoxicity removal and enhancement of biodegradability. Also, the consumption of ozone to achieve certain treatment goals (95% removal of ECs and 40% mineralization) is discussed. Results reveal that solar photocatalytic ozonation is a promising oxidation method as it led to the best results in terms of EC mineralization (∼85%), toxicity removal (∼90%) and efficient use of ozone (∼2mgO3mgEC(-1) to achieve complete EC removal and ∼18mgO3mgTOC(-1) to achieve 40% EC mineralization, respectively). Copyright © 2014 Elsevier Ltd. All rights reserved.

Using wastewater and high-rate algal ponds for nutrient removal and the production of bioenergy and biofuels.

PubMed

Batten, David; Beer, Tom; Freischmidt, George; Grant, Tim; Liffman, Kurt; Paterson, David; Priestley, Tony; Rye, Lucas; Threlfall, Greg

2013-01-01

This paper projects a positive outcome for large-scale algal biofuel and energy production when wastewater treatment is the primary goal. Such a view arises partly from a recent change in emphasis in wastewater treatment technology, from simply oxidising the organic matter in the waste (i.e. removing the biological oxygen demand) to removing the nutrients - specifically nitrogen and phosphorus - which are the root cause of eutrophication of inland waterways and coastal zones. A growing need for nutrient removal greatly improves the prospects for using new algal ponds in wastewater treatment, since microalgae are particularly efficient in capturing and removing such nutrients. Using a spreadsheet model, four scenarios combining algae biomass production with the making of biodiesel, biogas and other products were assessed for two of Australia's largest wastewater treatment plants. The results showed that super critical water reactors and anaerobic digesters could be attractive pathway options, the latter providing significant savings in greenhouse gas emissions. Combining anaerobic digestion with oil extraction and the internal economies derived from cheap land and recycling of water and nutrients on-site could allow algal oil to be produced for less than US$1 per litre.

Integration of coagulation and adsorption for removal of N-nitrosodimethylamine (NDMA) precursors from biologically treated municipal wastewater.

PubMed

Wang, Miaomiao; Meng, Yingjie; Ma, Defang; Wang, Yan; Li, Fengli; Xu, Xing; Xia, Chufan; Gao, Baoyu

2017-05-01

This study investigated the N-nitrosodimethylamine (NDMA) formation potential of various dissolved organic matter (DOM) fractions in biologically treated municipal wastewater by UF fractionation, XAD-8 resin adsorption isolation, and excitation and emission matrix (EEM) fluorescence spectroscopy. Removal of various NDMA precursor fractions was also analyzed to evaluate the efficiency of traditional water treatment processes (coagulation, adsorption, and coagulation-adsorption). Results showed that NDMA were mainly formed by low molecular weight (MW) fractions (<30 kDa) and hydrophilic fractions (HiS) in biologically treated municipal wastewater. Integrated coagulation-adsorption treatments showed the highest reduction capacity for NDMA formation potential (57%), followed by isolated adsorption treatment (50%) and isolated coagulation treatment (28%). The powdered activated carbon (PAC) adsorption process could reduce the high MW precursors (>30 kDa) by 48%, which was higher than other treatments. In contrast, the highest uptake (66%) of low MW precursors (<30 kDa) was achieved by the coagulation-adsorption process. All treatments preferentially removed the hydrophobic acids (HoA) fraction compared to other fractions. Coagulation could remove more fulvic acid-like substances and adsorption could remove more microbial by-products and aromatic proteins.

High-Temperature Particulate Matter Filtration with Resilient Yttria-Stabilized ZrO2 Nanofiber Sponge.

PubMed

Wang, Haolun; Lin, Sen; Yang, Shen; Yang, Xudong; Song, Jianan; Wang, Dong; Wang, Haiyang; Liu, Zhenglian; Li, Bo; Fang, Minghao; Wang, Ning; Wu, Hui

2018-05-01

Particulate matter (PM) is a major air pollutant in many regions, jeopardizing ecosystems and public health. Filtration at pollutant source is one of the most important ways to protect the environment, however, considering the high-temperature exhaust gas emissions, effective removal of PM and related pollutants from their sources remains a major challenge. In this study, a resilient, heat-resisting, and high-efficiency PM filter based on yttria-stabilized ZrO 2 (YSZ) nanofiber sponge produced with a scalable solution blow spinning process is reported. The porous 3D sponge composed of YSZ nanofibers is lightweight (density of 20 mg cm -3 ) and resilient at both room temperature and high temperatures. At room-temperature conditions, the YSZ nanofiber sponge exhibits 99.4% filtration efficiency for aerosol particles with size in the range of 20-600 nm, associated with a low pressure drop of only 57 Pa under an airflow velocity of 4.8 cm s -1 . At a high temperature of 750 °C, the ceramic sponge maintains a high filtration efficiency of 99.97% for PM 0.3-2.5 under a high airflow velocity of 10 cm s -1 . A practical vehicle exhaust filter to capture particles with filtration efficiency of >98.3% is also assembled. Hence, the YSZ nanofiber sponge has enormous potential to be applied in industry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrogen production in microbial reverse-electrodialysis electrolysis cells using a substrate without buffer solution.

PubMed

Song, Young-Hyun; Hidayat, Syarif; Kim, Han-Ki; Park, Joo-Yang

2016-06-01

The aim of this work was to use substrate without buffer solution in a microbial reverse-electrodialysis electrolysis cell (MREC) for hydrogen production under continuous flow condition (10 cell pairs of RED stacks, HRT=5, 7.5, and 15h). Decreasing in the HRT (increasing in the organic matter) made cell current stable and increased. Hydrogen gas was produced at a rate of 0.61m(3)-H2/m(3)-Van/d in H-MREC, with a COD removal efficiency of 81% (1.55g/L/d) and a Coulombic efficiency of 41%. This MREC system without buffer solution could successfully produce hydrogen gas at a consistent rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

A hybrid process of biofiltration of secondary effluent followed by ozonation and short soil aquifer treatment for water reuse.

PubMed

Zucker, I; Mamane, H; Cikurel, H; Jekel, M; Hübner, U; Avisar, D

2015-11-01

The Shafdan reclamation project facility (Tel Aviv, Israel) practices soil aquifer treatment (SAT) of secondary effluent with hydraulic retention times (HRTs) of a few months to a year for unrestricted agricultural irrigation. During the SAT, the high oxygen demand (>40 mg L(-1)) of the infiltrated effluent causes anoxic conditions and mobilization of dissolved manganese from the soil. An additional emerging problem is the occurrence of persistent trace organic compounds (TrOCs) in reclaimed water that should be removed prior to reuse. An innovative hybrid process based on biofiltration, ozonation and short SAT with ∼22 d HRT is proposed for treatment of the Shafdan secondary effluent to overcome limitations of the existing system and to reduce the SAT's physical footprint. Besides efficient removal of particulate matter to minimize clogging, coagulation/flocculation and filtration (5-6 m h(-1)) operated with the addition of hydrogen peroxide as an oxygen source efficiently removed dissolved organic carbon (DOC, to 17-22%), ammonium and nitrite. This resulted in reduced effluent oxygen demand during infiltration and oxidant (ozone) demand during ozonation by 23 mg L(-1) and 1.5 mg L(-1), respectively. Ozonation (1.0-1.2 mg O3 mg DOC(-1)) efficiently reduced concentrations of persistent TrOCs and supplied sufficient dissolved oxygen (>30 mg L(-1)) for fully oxic operation of the short SAT with negligible Mn(2+) mobilization (<50 μg L(-1)). Overall, the examined hybrid process provided DOC reduction of 88% to a value of 1.2 mg L(-1), similar to conventional SAT, while improving the removal of TrOCs and efficiently preventing manganese dissolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of emerging perfluorooctanoic acid and perfluorooctane sulfonate contaminants from lake water.

PubMed

Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Sarker, Dipok Chandra; Suja, Fatihah

2017-08-01

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the major polyfluoroalkyl substances (PFASs) contaminating global water environment. This study investigated the efficiency of granular activated carbon (GAC), ultrafiltration (UF) and nanofiltration (NF) treatment for removing PFOS and PFOA contaminants from lake water. NF gave greater removal of all contaminant types (in terms of organic matter, PFOS and PFOA) than GAC treatment which in turn was greater than UF treatment. The lower removal by UF was due to larger pore size of the membrane compared to the size of the target contaminants. For all treatment processes, lower pH (4) in the feedwater showed greater rejection of the organics and selected PFASs. This was likely due to increase in the electrostatic repulsion between solute and sorbent. It could be observed that on increasing the concentration of organics in the feed solution, the rejection of PFOA/PFOS decreased which was due to competition between organics and PFOS/PFOA for binding sites on the membrane/activated carbon surface. It was also noted that protein content led to greater influence for lower rejection of the PFOA/PFOS than carbohydrate or DOC content. This study demonstrated the potential use of membrane processes for removing emerging persistent organic pollutant removal from lake water.

Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles.

PubMed

Martin, Martin; Enríquez, L López; Fernández-Polanco, M; Villaverde, S; Garcia-Encina, P A

2007-01-01

Abstract Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350-500 mg COD/L, 110-130 mg NKT/L, 90-100 mg NH3-N/L and 12-15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm(-3)d(-1) and 0.16 kg total N m(-3)d(-1). The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

Impact of mild alkali dosage on immobilized Exiguobacterium spp. mediated cost and energy efficient sludge disintegration.

PubMed

Rajesh Banu, J; Ushani, U; Rajkumar, M; Naresh Kumar, R; Parthiba Karthikeyan, O

2017-12-01

Approaches to (extracellular polymeric substance) EPS removal were studied with major aim to enhance the biodegradability and sludge solubilization. In this study, a novel approach of entrapment of bacterial strain was carried out to achieve long term activity of protease secreting bacteria Exiguobacterium sp. A mild treatment of potassium hydroxide (KOH) was applied to remove EPS which was followed by entrapment under the biological pretreatment. The efficiency of Exiguobacterium was predicted through dissolvable organic and suspended solids (SS) reduction. The maximum dissolvable organic matter released was 2300mg/L with the solubilization of 23% which was obtained for sludge without EPS (SWOE). For dissolvable organic release, SWOE showed higher final methane production of 232mL/g COD at the production rate of 16.2mL/g COD.d. The SWOE pretreatment was found to be cost effective and less energy intensive beneficial in terms of energy and cost (43.9KWh and -8.2USD) when compared to sludge with EPS (SWE) pretreatment (-177.6KWh and -91.23USD). Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Organic Substances on the Efficiency of Fe(Ii) to Fe(Iii) Oxidation and Removal of Iron Compounds from Groundwater in the Sedimentation Process

NASA Astrophysics Data System (ADS)

Krupińska, Izabela

2017-09-01

One of the problems with iron removal from groundwater is organic matter. The article presents the experiments involved groundwater samples with a high concentration of total iron - amounting to 7.20 mgFe/dm3 and an increased amount of organic substances (TOC from 5.50 to 7.50 mgC/dm3). The water samples examined differed in terms of the value of the ratio of the TOC concentration and the concentration of total iron (D). It was concluded that with increase in the coexistence ratio of organic substances and total iron in water (D = [TOC]/[Fetot]), efficiency of Fe(II) to Fe(III) oxidization with dissolved oxygen decreased, while the oxidation time was increasing. This rule was not demonstrated for potassium manganate (VII) when used as an oxidizing agent. The application of potassium manganate (VII) for oxidation of Fe(II) ions produced the better results in terms of total iron concentration reduction in the sedimentation process than the oxidation with dissolved oxygen.

Decontamination efficiencies of pot-type water purifiers for ¹³¹I, ¹³⁴Cs and ¹³⁷Cs in rainwater contaminated during Fukushima Daiichi nuclear disaster.

PubMed

Higaki, Shogo; Hirota, Masahiro

2012-01-01

Rainwater was contaminated by a large release of radionuclides into the environment during the Fukushima Daiichi nuclear disaster. It became a matter of concern for Japan when several water purification plants detected ¹³¹I contamination in the drinking water. In the present study, the decontamination efficiency of two easily obtainable commercial water purifiers were examined for rainwater contaminated with ¹³¹I, ¹³⁴Cs and ¹³⁷Cs. The water purifiers removed 94.2-97.8% of the ¹³¹I and 84.2-91.5% of the ¹³⁴Cs and ¹³⁷Cs after one filtration. Seven filtrations removed 98.2-99.6% of the ¹³¹I and over 98.0% of the ¹³⁴Cs and ¹³⁷Cs. From a practical perspective, over the fourth filtrations were not needed because of no significant improvements after the third filtration.

Recirculation of gas emissions to achieve advanced denitrification of the effluent from the anaerobic treatment of domestic wastewater.

PubMed

Pelaz, L; Gómez, A; Garralón, G; Letona, A; Fdz-Polanco, M

2018-02-01

A denitrifying pilot plant was designed, constructed and operated for more than five months. The plant treated domestic wastewater with high ammonium nitrogen concentration, which had previously undergone an anaerobic process at 18 °C. The process consisted of one biofilter with 2 h of hydraulic retention time for denitritation. Different synthetic nitrite concentrations were supplied to the anoxic reactor to simulate the effluent of a nitritation process. This work investigates the advanced denitritation of wastewater using the organic matter and other alternative electron donors present in an anaerobic treatment process effluent: methane and sulfide. The denitrifying bacteria were able to treat wastewater at an inlet nitrite concentration of 75 mg NO 2 - -N/L with a removal efficiency of 92.9%. When the inlet nitrite concentration was higher, the recirculation of the gas from the top of the anoxic reactor was successful to enhance the nitrite removal, achieving a NO 2 - elimination efficiency of 98.3%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Studies on the integration of nanofiltration and soil treatment for municipal effluent reclamation as a groundwater supplement.

PubMed

Linlin, Wu; Xuan, Zhao; Meng, Zhang

2010-01-01

Water shortage leads to increasing attention to artificial groundwater recharge by reclaimed water. An injection well is the most common recharge approach. In this paper, a new kind of integrated technology-short-term vadose soil treatment followed by nanofiltration-is recommended as pretreatment for artificial groundwater recharge by an injection well. Laboratory-scale experiments demonstrate that the short-term vadose soil can remove approximately 30% of the total dissolved organic carbon (DOC) content and 40% of dissolved organic matter with a molecular weight less than 1 kDa. As a compensatory process of soil treatment, nanofiltration offers a favorable desalination and additional organics removal. The removal efficiencies for total dissolved solids and conductivity amount to 45 and 48%, respectively. The residual DOC in the final effluent is below 1.0 mg/L. In addition, short-term vadose soil offers effective elimination of aromatic protein-like and polysaccharide-like substances, which are detected as components of the membrane foulant.

Performance of anaerobic fluidized membrane bioreactors using effluents of microbial fuel cells treating domestic wastewater.

PubMed

Kim, Kyoung-Yeol; Yang, Wulin; Ye, Yaoli; LaBarge, Nicole; Logan, Bruce E

2016-05-01

Anaerobic fluidized membrane bioreactors (AFMBRs) have been mainly developed as a post-treatment process to produce high quality effluent with very low energy consumption. The performance of an AFMBR was examined using the effluent from a microbial fuel cell (MFC) treating domestic wastewater, as a function of AFMBR hydraulic retention times (HRTs) and organic matter loading rates. The MFC-AFMBR achieved 89 ± 3% removal of the chemical oxygen demand (COD), with an effluent of 36 ± 6 mg-COD/L over 112 days operation. The AFMBR had very stable operation, with no significant changes in COD removal efficiencies, for HRTs ranging from 1.2 to 3.8h, although the effluent COD concentration increased with organic loading. Transmembrane pressure (TMP) was low, and could be maintained below 0.12 bar through solids removal. This study proved that the AFMBR could be operated with a short HRT but a low COD loading rate was required to achieve low effluent COD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Understanding the factors influencing the removal of heavy metals in urban stormwater runoff.

PubMed

Maniquiz-Redillas, Marla C; Kim, Lee-Hyung

2016-01-01

In this research, an infiltration trench equipped with an extensive pretreatment and filter bed consisting of woodchip, sand and gravel was utilized as a low impact development technique to manage stormwater runoff from a highly impervious road with particular emphasis on heavy metal removal. Findings revealed that the major factors influencing the removal of heavy metals were the concentration of the particulate matters and heavy metals in runoff, runoff volume and flow rates. The reduction of heavy metals was enhanced by sedimentation of particulates through pretreatment. Fine particles (<2 mm) had the most significant amount of heavy metals, thus, enhanced adsorption and filtration using various filter media were important design considerations. Sediment was most highly attached on the surface area of woodchip than to other filter media like sand, gravel and geotextile. It is suggested that maintenance must be performed after the end of the winter season wherein high sediment rate was observed to maintain the efficiency of the treatment system.

Removal of lead from aqueous solutions with a treated spent bleaching earth.

PubMed

Mana, Mohamed; Ouali, Mohand Said; Lindheimer, Marc; Menorval, Louis Charles de

2008-11-30

A spent bleaching earth from an edible oil refinery has been treated by impregnation with a normal sodium hydroxide solution followed by mild thermal treatment (100 degrees C). The obtained material (TSBE) was washed, dried and characterized by X-ray diffraction, FTIR, SEM, BET and thermal analysis. The clay structure was not apparently affected by the treatment and the impregnated organic matter was quantitatively removed. We have investigated the sorption of lead on this material, the spent bleaching earth (SBE) and the virgin bleaching earth (VBE). The kinetic results fit the pseudo second-order kinetic model and the Weber & Morris, intraparticle diffusion model. The pH had effect on the sorption efficiency. The sorption isotherms followed the Langmuir model for various sorbent concentrations with good values of determination coefficient. A comparison between the results obtained with this material and those of the literature highlighted a good removal capacity of the treated spent bleaching earth at low cost.

Optimized Extraction Method To Remove Humic Acid Interferences from Soil Samples Prior to Microbial Proteome Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Chen; Hettich, Robert L.

The microbial composition and their activities in soil environments play a critical role in organic matter transformation and nutrient cycling, perhaps most specifically with respect to impact on plant growth but also more broadly to global impact on carbon and nitrogen-cycling. Liquid chromatography coupled to high performance mass spectrometry provides a powerful approach to characterize soil microbiomes; however, the limited microbial biomass and the presence of abundant interferences in soil samples present major challenges to soil proteome extraction and subsequent MS measurement. To address some of the major issues, we have designed and optimized an experimental method to enhance microbialmore » proteome extraction concomitant with minimizing the soil-borne humic substances co-extraction from soils. Among the range of interferences, humic substances are often the worst in terms of adversely impacting proteome extraction and mass spectrometry measurement. Our approach employs an in-situ detergent-based microbial lysis / TCA precipitation coupled with an additional acidification precipitation step at the peptide level which efficiently removes humic acids. By combing filtration and pH adjustment of the final peptide solution, the remaining humic acids can be differentially precipitated and removed with a membrane filter, thereby leaving much cleaner proteolytic peptide samples for MS measurement. As a result, this modified method is a reliable and straight-forward protein extraction method that efficiently removes soil-borne humic substances without inducing proteome sample loss or reducing or biasing protein identification in mass spectrometry.« less

Optimized Extraction Method To Remove Humic Acid Interferences from Soil Samples Prior to Microbial Proteome Measurements

DOE PAGES

Qian, Chen; Hettich, Robert L.

2017-05-24

The microbial composition and their activities in soil environments play a critical role in organic matter transformation and nutrient cycling, perhaps most specifically with respect to impact on plant growth but also more broadly to global impact on carbon and nitrogen-cycling. Liquid chromatography coupled to high performance mass spectrometry provides a powerful approach to characterize soil microbiomes; however, the limited microbial biomass and the presence of abundant interferences in soil samples present major challenges to soil proteome extraction and subsequent MS measurement. To address some of the major issues, we have designed and optimized an experimental method to enhance microbialmore » proteome extraction concomitant with minimizing the soil-borne humic substances co-extraction from soils. Among the range of interferences, humic substances are often the worst in terms of adversely impacting proteome extraction and mass spectrometry measurement. Our approach employs an in-situ detergent-based microbial lysis / TCA precipitation coupled with an additional acidification precipitation step at the peptide level which efficiently removes humic acids. By combing filtration and pH adjustment of the final peptide solution, the remaining humic acids can be differentially precipitated and removed with a membrane filter, thereby leaving much cleaner proteolytic peptide samples for MS measurement. As a result, this modified method is a reliable and straight-forward protein extraction method that efficiently removes soil-borne humic substances without inducing proteome sample loss or reducing or biasing protein identification in mass spectrometry.« less

Biological nutrient removal with limited organic matter using a novel anaerobic–anoxic/oxic multi-phased activated sludge process

PubMed Central

Naseer, Rusul; Abualhail, Saad; Xiwu, Lu

2012-01-01

An anaerobic–anoxic/oxic (A2/O) multi-phased biological process called “phased isolation tank step feed technology (PITSF)” was developed to force the oscillation of organic and nutrient concentrations in process reactors. PITSF can be operated safely with a limited carbon source in terms of low carbon requirements and aeration costs whereas NAR was achieved over 95% in the last aerobic zone through a combination of short HRT and low DO levels. PCR assay was used for XAB quantification to correlate XAB numbers with nutrient removal. PCR assays showed, high NAR was achieved at XAB population 5.2 × 108 cells/g MLVSS in response to complete and partial nitrification process. It was exhibited that low DO with short HRT promoted XAB growth. Simultaneous nitrification and denitrification (SND) via nitrate were observed obviously, SND rate was between 69–72%, at a low DO level of 0.5 mg/l in the first aerobic tank during main phases and the removal efficiency of TN, NH4+-N, COD, TP was 84.7 .97, 88.3 and 96% respectively. The removal efficiencies of TN, NH4+-N, and TP at low C/N ratio and DO level were 84.2, 98.5 and 96.9% respectively which were approximately equal to the complete nitrification–denitrification with the addition of external carbon sources at a normal DO level of (1.5–2.5 mg/l). PMID:23961214

Wet air oxidation and catalytic wet air oxidation for dyes degradation.

PubMed

Ovejero, Gabriel; Sotelo, José Luis; Rodríguez, Araceli; Vallet, Ana; García, Juan

2011-11-01

Textile industry produces wastewater which contributes to water pollution since it utilizes a lot of chemicals. Preliminary studies show that the wastewater from textile industries contains grease, wax, surfactant, and dyes. The objective of this study was to determine the treatment efficiency of the nickel catalysts supported on hydrotalcites in three-dye model compounds and two types of wastewater. Hydrotalcites were employed to prepare supported nickel catalysts by wetness impregnation technique. Metal loadings from 1 to 10 wt% were tested. Catalysts were characterized by several techniques. They were tested in a catalytic wet air oxidation of three dyes and two wastewaters with different origins. It could be observed that the higher the metal content, the lower the BET area, possibly due to sintering of Ni and the consequent blocking of the pores by the metal. In addition, metallic dispersion was also higher when the metal content was lower. Dye conversion was more than 95% for every catalyst showing no differences with the nickel content. A high degree of dye conversion was achieved. Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) processes have been proved to be extremely efficient in TOC removal for wastewaters. The CWAO process can be used to remove dyes from wastewater. Three different dyes were tested showing satisfactory results in all of them. TOC degradation and dye removal in the presence of the catalyst were effective. Also, the HTNi catalyst is very active for organic matter and toxicity removal in wastewaters.

Cr(VI)-contaminated groundwater remediation with simulated permeable reactive barrier (PRB) filled with natural pyrite as reactive material: Environmental factors and effectiveness.

PubMed

Liu, Yuanyuan; Mou, Haiyan; Chen, Liqun; Mirza, Zakaria A; Liu, Li

2015-11-15

Permeable reactive barriers (PRBs) are efficient technologies for in situ remediation of contaminated groundwater, the effectiveness of which greatly depends on the reactive media filled. Natural pyrite is an iron sulfide material with a very low content of iron and sulfur, and a mining waste which is a potential material for Cr(VI) immobilization. In this study, we conducted a series of batch tests to research the effects of typical environmental factors on Cr(VI) removal and also simulated PRB filled with natural pyrite to investigate its effectiveness, in order to find a both environmentally and economically fine method for groundwater remediation. Batch tests showed that pH had the significant impact on Cr(VI) removal with an apparently higher efficiency under acidic conditions, and dissolved oxygen (DO) would inhibit Cr(VI) reduction; a relatively high initial Cr(VI) concentration would decrease the rate of Cr(VI) sorption; ionic strength and natural organic matter resulted in no significant effects on Cr(VI) removal. Column tests demonstrated that the simulated PRB with natural pyrite as the reactive media was considerably effective for removing Cr(VI) from groundwater, with a sorption capability of 0.6222 mg Cr per gram of natural pyrite at an initial Cr(VI) concentration of 10mg/L at pH 5.5 in an anoxic environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Soil Organic Matter in Its Native State: Unravelling the Most Complex Biomaterial on Earth.

PubMed

Masoom, Hussain; Courtier-Murias, Denis; Farooq, Hashim; Soong, Ronald; Kelleher, Brian P; Zhang, Chao; Maas, Werner E; Fey, Michael; Kumar, Rajeev; Monette, Martine; Stronks, Henry J; Simpson, Myrna J; Simpson, André J

2016-02-16

Since the isolation of soil organic matter in 1786, tens of thousands of publications have searched for its structure. Nuclear magnetic resonance (NMR) spectroscopy has played a critical role in defining soil organic matter but traditional approaches remove key information such as the distribution of components at the soil-water interface and conformational information. Here a novel form of NMR with capabilities to study all physical phases termed Comprehensive Multiphase NMR, is applied to analyze soil in its natural swollen-state. The key structural components in soil organic matter are identified to be largely composed of macromolecular inputs from degrading biomass. Polar lipid heads and carbohydrates dominate the soil-water interface while lignin and microbes are arranged in a more hydrophobic interior. Lignin domains cannot be penetrated by aqueous solvents even at extreme pH indicating they are the most hydrophobic environment in soil and are ideal for sequestering hydrophobic contaminants. Here, for the first time, a complete range of physical states of a whole soil can be studied. This provides a more detailed understanding of soil organic matter at the molecular level itself key to develop the most efficient soil remediation and agricultural techniques, and better predict carbon sequestration and climate change.

Sustaining aspen productivity in the Lake States

Treesearch

Douglas M. Stone

2001-01-01

Sustaining forest productivity requires maintaining soil productivity. Management activities that decrease soil porosity and remove organic matter can reduce productivity. We determined effects of three levels of organic matter removal (OMR) and soil compaction on aspen regeneration and growth following winter harvest of aspen-dominated stands in northern Minnesota,...

Removal of trace nonylphenol from water in the coexistence of suspended inorganic particles and NOMs by using a cellulose-based flocculant.

PubMed

Yang, Zhen; Ren, Kexin; Guibal, Eric; Jia, Shuying; Shen, Jiachun; Zhang, Xuntong; Yang, Weiben

2016-10-01

A flocculation method was used for the removal of trace nonylphenol (NP) from synthetic surface water containing natural organic matters (humic acid, HA) and suspended inorganic particles (kaolin). A polymeric flocculant (CMCND), with enhanced cationic property and unique switchable hydrophobic/hydrophilic characteristic, was specially designed for this application. CMCND showed a high efficiency for trace NP removal, turbidity and UV254 abatements: under optimized conditions (pH: 4; T: 35 °C; dosage: 40 mg/L), the removal of NP reached up to 79%. By using dosage-pH flocculation diagrams and correlation analyses as tools, kaolin and HA were found to exert synergistic effects on NP removal, with the aid of CMCND; the synergistic effect of HA is higher due to π-π stacking. Zeta potential-dosage profiles clearly demonstrated charge neutralization predominated at pH 4, due to the strong cationic groups in the flocculant. Floc size monitoring displayed that the delayed phase transformation process (from hydrophilicity to hydrophobicity) of CMCND at 35 °C enhanced NP removal. In addition, spectral analyses clarified the interactions among CMCND, NP, kaolin and HA: charge attraction and hydrophobic interaction between CMCND and NP played the key roles. The findings are of significance for removing endocrine-disrupting chemicals in environmental remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Importance of organic amendment characteristics on bioremediation of PAH-contaminated soil.

PubMed

Lukić, B; Huguenot, D; Panico, A; Fabbricino, M; van Hullebusch, E D; Esposito, G

2016-08-01

This study investigates the importance of the organic matter characteristics of several organic amendments (i.e., buffalo manure, food and kitchen waste, fruit and vegetables waste, and activated sewage sludge) and their influence in the bioremediation of a polycyclic aromatic hydrocarbons (PAH)-contaminated soil. The removal of low molecular weights (LMW) and high molecular weights (HMW) PAHs was monitored in four bioremediation reactors and used as an indicator of the role of organic amendments in contaminant removal. The total initial concentration of LMW PAHs was 234 mg kg(-1) soil (dry weight), while the amount for HMW PAHs was 422 mg kg(-1) soil (dry weight). Monitoring of operational parameters and chemical analysis was performed during 20 weeks. The concentrations of LMW PAH residues in soil were significantly lower in reactors that displayed a mesophilic phase, i.e., 11 and 15 %, compared to reactors that displayed a thermophilic phase, i.e., 29 and 31 %. Residual HMW PAHs were up to five times higher compared to residual LMW PAHs, depending on the reactor. This demonstrated that the amount of added organic matter and macronutrients such as nitrogen and phosphorus, the biochemical organic compound classes (mostly soluble fraction and proteins), and the operational temperature are important factors affecting the overall efficiency of bioremediation. On that basis, this study shows that characterization of biochemical families could contribute to a better understanding of the effects of organic amendments and clarify their different efficiency during a bioremediation process of PAH-contaminated soil.

Coagulation efficiency and flocs characteristics of recycling sludge during treatment of low temperature and micro-polluted water.

PubMed

Zhou, Zhiwei; Yang, Yanling; Li, Xing; Gao, Wei; Liang, Heng; Li, Guibai

2012-01-01

Drinking water treatment sludge, characterized as accumulated suspended solids and organic and inorganic matter, is produced in large quantities during the coagulation process. The proper disposal, regeneration or reuse of sludge is, therefore, a significant environmental issue. Reused sludge at low temperatures is an alternative method to enhance traditional coagulation efficiency. In the present study, the recycling mass of mixed sludge and properties of raw water (such as pH and turbidity) were systematically investigated to optimize coagulation efficiency. We determined that the appropriate dosage of mixed sludge was 60 mL/L, effective initial turbidity ranges were below 45.0 NTU, and optimal pH for DOMs and turbidity removal was 6.5-7.0 and 8.0, respectively. Furthermore, by comparing the flocs characteristics with and without recycling sludge, we found that floc structures with sludge were more irregular with average size growth to 64.7 microm from 48.1 microm. Recycling sludge was a feasible and successful method for enhancing pollutants removal, and the more irregular flocs structure after recycling might be caused by breakage of reused flocs and incorporation of powdered activated carbon into larger flocs structure. Applied during the coagulation process, recycling sludge could be significant for the treatment of low temperature and micro-polluted source water.

Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones.

PubMed

Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M; Revsbech, Niels Peter; Löscher, Carolin; Schunck, Harald; Desai, Dhwani K; Hauss, Helena; Kiko, Rainer; Holtappels, Moritz; LaRoche, Julie; Schmitz, Ruth A; Graco, Michelle I; Kuypers, Marcel M M

2015-01-01

Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our results suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100%) in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein.

Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

PubMed Central

Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M.; Revsbech, Niels Peter; Löscher, Carolin; Schunck, Harald; Desai, Dhwani K.; Hauss, Helena; Kiko, Rainer; Holtappels, Moritz; LaRoche, Julie; Schmitz, Ruth A.; Graco, Michelle I.; Kuypers, Marcel M. M.

2015-01-01

Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our results suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100%) in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein. PMID:26192623

Comparison of methods for hydrocarbon analysis of marine biota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gritz, R.L.; Shaw, D.G.

1977-04-01

A comparison was made of several procedures for the isolation of hydrocarbons from other matter and for the fractionation of hydrocarbons according to chemical type. The efficiency of Soxhlet extraction followed by saponification with extraction by alkaline digestion (direct saponification) was compared using two hour and 24 hour reaction times. All procedures were performed on approximately 60 g of soft parts of Saxidomus gigantea (butter clam). The 24 hour saponification and column chromatography on partially deactivated columns constituted the best procedure tested. Soxhlet extraction followed by two hour saponification did not completely remove methyl esters and was the most laboriousmore » technique. Direct two hour saponification was also questionable in the removal of esters and led to severe emulsion problems. The recoveries of hydrocarbons by the three procedures was substantially the same.« less

Simultaneous removal of As, Cd, Cr, Cu, Ni and Zn from stormwater using high-efficiency industrial sorbents: Effect of pH, contact time and humic acid.

PubMed

Genç-Fuhrman, Hülya; Mikkelsen, Peter S; Ledin, Anna

2016-10-01

The effect of contact time, solution pH, and the presence of humic acid (HA) on the combined removal of As, Cd, Cr, Cu, Ni and Zn is investigated in batch tests using alumina, granulated activated carbon (GAC), and bauxsol coated sand (BCS) as sorbents. It is found that the equilibrium time for Cd, Cu, Ni and Zn is about 4h, while no clear equilibrium is observed for As and Cr. It is also found that increasing the pH until pH~8 enhanced Cd, Cu, Ni and Zn removal, but increasing the pH above this point had no major effect. In the cases of As and Cr, higher pH values (i.e. >7) decreased their removal. The presence of both 20 and 100mg/L HA suppressed the heavy metal removal except for Cr, and the suppression was higher at the higher HA concentration. Geochemical simulations suggest that this is due to the formation of dissolved HA-metal complexes preventing effective metal sorption. In the case of Cr, the presence of HA increased the removal when using alumina or BCS, while hindering the removal when using GAC. The findings show that the pH-value of the stormwater to be treated must be in the range of 6-7 in order to achieve removal of the full spectrum of metals. The results also show that natural organic matter may severely influence the removal efficiency, such that, for most metals the removal was reduced to the half, while for Cr it was increased to the double for alumina and BCS. Consequently, a properly working filter set up may not work properly anymore when receiving high loads of natural organic acids during the pollen season in spring or during defoliation in autumn and early winter, and during mixing of runoff with snowmelt having a low pH. Copyright © 2016 Elsevier B.V. All rights reserved.

Anaerobic ammonia removal in presence of organic matter: a novel route.

PubMed

Sabumon, P C

2007-10-01

This study describes the feasibility of anaerobic ammonia removal process in presence of organic matter. Different sources of biomass collected from diverse eco-systems containing ammonia and organic matter (OM) were screened for potential anaerobic ammonia removal. Sequential batch studies confirmed the possibility of anaerobic ammonia removal in presence of OM, but ammonia was oxidized anoxically to nitrate (at oxidation reduction potential; ORP=-248+/-25 mV) by an unknown mechanism unlike in the reported anammox process. The oxygen required for oxidation of ammonia might have been generated through catalase enzymatic activity of facultative anaerobes in mixed culture. The oxygen generation possibility by catalase enzyme route was demonstrated. Among the inorganic electron acceptors (NO(2)(-), NO(3)(-) and SO(4)(2-)) studied, NO(2)(-) was found to be most effective in total nitrogen removal. Denitrification by the developed culture was much effective and faster compared to ammonia oxidation. The results of this study show that anaerobic ammonia removal is feasible in presence of OM. The novel nitrogen removal route is hypothesized as enzymatic anoxic oxidation of NH(4)(+) to NO(3)(-), followed by denitrification via autotrophic and/or heterotrophic routes. The results of batch study were confirmed in continuous reactor operation.

Characterization of Natural Organic Matter by FeCl3 Coagulation

NASA Astrophysics Data System (ADS)

Cahyonugroho, O. H.; Hidayah, E. N.

2018-01-01

Natural organic matter (NOM) is heterogenous mixture of organic compounds that enter the water from various decomposition and metabolic reactions, including animal, plant, domestic and industrial wastes. NOM refers to group of carbon-based compounds that are found in surface water and ground water. The aim of the study is to assess organic matter characteristics in Jagir River as drinking water source and to characterize the organic components that could be removed during coagulation. Coagulation is the common water treatment process can be used to remove NOM with FeCl3 coagulant in various dosage. NOM surrogates, including total organic carbon (TOC), ultraviolet absorbance at 254 nm (UV254) and specific UV absorbance (SUVA) were chosen to assess the organic removal. Results of jar test experiments showed that NOM can be removed about 40% of NOM surrogates with 200 mg/L FeCl3. About 60% removal of total organic fraction, which is mainly humic substances, as detected by size exclusion chromatography (SEC).

Removal of dissolved organic matter by anion exchange: Effect of dissolved organic matter properties

USGS Publications Warehouse

Boyer, T.H.; Singer, P.C.; Aiken, G.R.

2008-01-01

Ten isolates of aquatic dissolved organic matter (DOM) were evaluated to determine the effect that chemical properties of the DOM, such as charge density, aromaticity, and molecular weight, have on DOM removal by anion exchange. The DOM isolates were characterized asterrestrial, microbial, or intermediate humic substances or transphilic acids. All anion exchange experiments were conducted using a magnetic ion exchange (MIEX) resin. The charge density of the DOM isolates, determined by direct potentiometric titration, was fundamental to quantifying the stoichiometry of the anion exchange mechanism. The results clearly show that all DOM isolates were removed by anion exchange; however, differences among the DOM isolates did influence their removal by MIEX resin. In particular, MIEX resin had the greatest affinity for DOM with high charge density and the least affinity for DOM with low charge density and low aromaticity. This work illustrates that the chemical characteristics of DOM and solution conditions must be considered when evaluating anion exchange treatment for the removal of DOM. ?? 2008 American Chemical Society.

Volatile particles measured by vapor-particle separator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Meng -Dawn; Corporan, Edwin

Vapor-Particle Separator (VPS) is a new technology developed for characterization of the volatile fraction of particulate matter in a combustion aerosol population. VPS incorporates a novel metallic membrane and operates in a cross-flow filtration mode for separation of vapor and solid (i.e. non-volatile) particles. Demonstration of the VPS technology on aircraft engine-emitted particles has led to the improvement of the technology and increased confidence on the robustness of its field performance. In this study, the performance of the VPS was evaluated against the Particle Measurement Programme (PMP) volatile particle remover (VPR), a standardized device used in heavy duty diesel enginesmore » for separation and characterization of non-volatile particulate matter. Using tetracontane particles in the laboratory reveals that the VPS performed reasonably well in removing the volatile species. In the field conditions, a single-mode particle size distribution was found for emitted particles from a T63 turboshaft engine at both idle and cruise engine power conditions. Removal of the volatile T63 engine particles by the VPS was consistent with that of PMP VPR. In tests on an F117 turbofan engine, the size distribution at the idle (4% rated) engine power condition was found to be bimodal, with the first mode consisting of particles smaller than 10nm, which are believed to be mostly semi-volatile particles, while the second mode of larger size was a mixture of semi-volatile and non-volatile particles. The distribution was single modal at the 33% rated engine power with no secondary mode observed. Altogether, for particles emitted by both engines, the removal efficiency of the VPS appears to surpass that of the PMP VPR by 8-10%.« less

Integration of the Anammox process to the rejection water and main stream lines of WWTPs.

PubMed

Morales, Nicolás; Val Del Río, Ángeles; Vázquez-Padín, José Ramón; Méndez, Ramón; Mosquera-Corral, Anuska; Campos, José Luis

2015-12-01

Nowadays the application of Anammox based processes in the wastewater treatment plants has given a step forward. The new goal consists of removing the nitrogen present in the main stream of the WWTPs to improve their energetic efficiencies. This new approach aims to remove not only the nitrogen but also to provide a better use of the energy contained in the organic matter. The organic matter will be removed either by an anaerobic psychrophilic membrane reactor or an aerobic stage operated at low solids retention time followed by an anaerobic digestion of the generated sludge. Then ammonia coming from these units will be removed in an Anammox based process in a single unit system. The second strategy provides the best results in terms of operational costs and would allow reductions of about 28%. Recent research works performed on Anammox based processes and operated at relatively low temperatures and/or low ammonia concentrations were carried out in single-stage systems using biofilms, granules or a mixture of flocculent nitrifying and granular Anammox biomasses. These systems allowed the appropriated retention of Anammox and ammonia oxidizing bacteria but also the proliferation of nitrite oxidizing bacteria which seems to be the main drawback to achieve the required effluent quality for disposal. Therefore, prior to the implementation of the Anammox based processes at full scale to the water line, a reliable strategy to avoid nitrite oxidation should be defined in order to maintain the process stability and to obtain the desired effluent quality. If not, the application of a post-denitrification step should be necessary. Copyright © 2015 Elsevier Ltd. All rights reserved.

Volatile particles measured by vapor-particle separator

DOE PAGES

Cheng, Meng -Dawn; Corporan, Edwin

2016-08-25

Vapor-Particle Separator (VPS) is a new technology developed for characterization of the volatile fraction of particulate matter in a combustion aerosol population. VPS incorporates a novel metallic membrane and operates in a cross-flow filtration mode for separation of vapor and solid (i.e. non-volatile) particles. Demonstration of the VPS technology on aircraft engine-emitted particles has led to the improvement of the technology and increased confidence on the robustness of its field performance. In this study, the performance of the VPS was evaluated against the Particle Measurement Programme (PMP) volatile particle remover (VPR), a standardized device used in heavy duty diesel enginesmore » for separation and characterization of non-volatile particulate matter. Using tetracontane particles in the laboratory reveals that the VPS performed reasonably well in removing the volatile species. In the field conditions, a single-mode particle size distribution was found for emitted particles from a T63 turboshaft engine at both idle and cruise engine power conditions. Removal of the volatile T63 engine particles by the VPS was consistent with that of PMP VPR. In tests on an F117 turbofan engine, the size distribution at the idle (4% rated) engine power condition was found to be bimodal, with the first mode consisting of particles smaller than 10nm, which are believed to be mostly semi-volatile particles, while the second mode of larger size was a mixture of semi-volatile and non-volatile particles. The distribution was single modal at the 33% rated engine power with no secondary mode observed. Altogether, for particles emitted by both engines, the removal efficiency of the VPS appears to surpass that of the PMP VPR by 8-10%.« less

Highly integrated hybrid process with ceramic ultrafiltration-membrane for advanced treatment of drinking water: a pilot study.

PubMed

Guo, Jianning; Wang, Lingyun; Zhu, Jia; Zhang, Jianguo; Sheng, Deyang; Zhang, Xihui

2013-01-01

This article presents a highly integrated hybrid process for the advanced treatment of drinking water in dealing with the micro-polluted raw water. A flat sheet ceramic membrane with the pore size of 50∼60 nm for ultrafiltration (UF) is used to integrate coagulation and ozonation together. At the same time, biological activated carbon filtration (BAC) is used to remove the ammonia and organic pollutants in raw water. A pilot study in the scale of 120 m(3)/d has been conducted in Southern China. The mainly-analyzed parameters include turbidity, particle counts, ammonia, total organic carbon (TOC), UV254, biological dissolved organic carbon (BDOC), dissolved oxygen (DO) as well as trans-membrane pressure (TMP). The experiments demonstrated that ceramic UF-membrane was able to remove most of turbidity and suspended particulate matters. The final effluent turbidity reached to 0.14 NTU on average. BAC was effective in removing ammonia and organic matters. Dissolved oxygen (DO) is necessary for the biodegradation of ammonia at high concentration. The removal efficiencies reached to 90% for ammonia with the initial concentration of 3.6 mg/L and 76% for TOC with the initial concentration of 3.8 mg/L. Ozonation can alter the molecular structure of organics in terms of UV254, reduce membrane fouling, and extend the operation circle. It is believed the hybrid treatment process developed in this article can achieve high performance with less land occupation and lower cost compared with the conventional processes. It is especially suitable for the developing countries in order to obtain high-quality drinking water in a cost-effective way.

The effect of acidic pH and presence of metals as parameters in establishing a sulfidogenic process in anaerobic reactor.

PubMed

Vieira, Bárbara F; Couto, Pâmela T; Sancinetti, Giselle P; Klein, Bernhard; van Zyl, Dirk; Rodriguez, Renata P

2016-08-23

The successful use of anaerobic reactors for bioremediation of acid mine drainage has been shown in systems with neutral pH. However, the choice of an efficient and suitable process for such wastewater must consider the capability of operating at acidic pH and in the presence of metals. This work studies the performance of an anaerobic batch reactor, under conditions of varying initial pH for its efficiencies in sulfate removal and metal precipitation from synthetic acid mine drainage. The chemical oxygen demand/sulfate (COD/SO4(2-)) ratio used was 1.00, with ethanol chosen as the only energy and carbon source. The initial pH of the synthetic drainage was progressively set from 7.0 to 4.0 to make it as close as possible to that of real acid mine drainage. Metals were also added starting with iron, zinc, and finally copper. The effectiveness of sulfate and COD removal from the synthetic acid mine drainage increased as the initial pH was reduced. The sulfate removal increased from 38.5 ± 3.7% to 52.2 ± 3%, while the removal of organic matter started at 91.7 ± 2.4% and ended at 99 ± 1%. These results indicate that the sulfate reducing bacteria (SRB) community adapted to lower pH values. The metal removal observed was 88 ± 7% for iron, 98.0 ± 0.5% for zinc and 99 ± 1% for copper. At this stage, an increase in the sulfate removal was observed, which reaches up to 82.2 ± 5.8%. The kinetic parameters for sulfate removal were 0.22 ± 0.04 h(-1) with Fe, 0.26 ± 0.04 h(-1) with Fe and Zn and 0.44 ± 0.04 h(-1) with Fe, Zn, and Cu.

Microbial community responses in forest mineral soil to compaction, organic matter removal, and vegetation control

Treesearch

Matt D. Busse; Samual E. Beattie; Robert F. Powers; Felipe G. Sanchez; Allan E. Tiarks

2006-01-01

We tested three disturbance hypotheses in young conifer plantations: H1: soil compaction and removal of surface organic matter produces sustained changes in microbial community size, activity, and structure in mineral soil; H2: microbial community characteristics in mineral soil are linked to the recovery of plant diversity...

Use of ozone in a pilot-scale plant for textile wastewater pre-treatment: physico-chemical efficiency, degradation by-products identification and environmental toxicity of treated wastewater.

PubMed

Somensi, Cleder A; Simionatto, Edésio L; Bertoli, Sávio L; Wisniewski, Alberto; Radetski, Claudemir M

2010-03-15

In this study, ozonation of raw textile wastewater was conducted in a pilot-scale plant and the efficiency of this treatment was evaluated based on the parameters color removal and soluble organic matter measured as chemical oxygen demand (COD), at two pH values (9.1 and 3.0). Identification of intermediate and final degradation products of ozone pre-treatment, as well as the evaluation of the final ecotoxicity (Lumistox test) of pre-treated wastewater, was also carried out. After 4h of ozone treatment with wastewater recirculation (flow rate of 0.45 m(3)h(-1)) the average efficiencies for color removal were 67.5% (pH 9.1) and 40.6% (pH 3.0), while COD reduction was 25.5% (pH 9.1) and 18.7% (pH 3.0) for an ozone production capacity of 20 g h(-1). Furthermore, ozonation enhances the biodegradability of textile wastewater (BOD(5)/COD ratios) by a factor of up to 6.8-fold. A GC-MS analysis of pre-treated textile wastewater showed that some products were present at the end of the pre-treatment time. In spite of this fact, the bacterial luminescence inhibition test (Lumistox test) showed a significant toxicity reduction on comparing the raw and treated textile wastewater. In conclusion, pre-ozonation of textile wastewater is an important step in terms of improving wastewater biodegradability, as well as reducing acute ecotoxicity, which should be removed completely through sequential biological treatment. (c) 2009. Published by Elsevier B.V.

Fluidized-bed Fenton coupled with ceramic membrane separation for advanced treatment of flax wastewater.

PubMed

Fan, Dong; Ding, Lili; Huang, Hui; Chen, Mengtian; Ren, Hongqiang

2017-10-15

Fluidized-bed Fenton coupled with ceramic membrane separation to treat the flax secondary effluent was investigated. The operating variables, including initial pH, dosage of H 2 O 2 and Fe 0 , air flow rate, TMP and pore size, were optimized. The distributions of DOMs in the treatment process were analyzed. Under the optimum condition (600mgL -1 H 2 O 2 , 1.4gL -1 Fe 0 , pH=3, 300Lh -1 air flow rate and 15psi TMP), the highest TOC and color removal efficiencies were 84% and 94% in the coupled reactor with 100nm ceramic membrane, reducing 39% of total iron with similar removal efficiency compared with Fluidized-bed Fenton. Experimental results showed that the ceramic membrane could intercept catalyst particles (average particle size >100nm), 10.4% macromolecules organic matter (AMW>20000Da) and 12.53% hydrophobic humic-like component. EEM-PARAFAC identified four humic-like (M1-M4) and one protein-like components (M5), and the fluorescence intensities of M1-M5 in the secondary effluent were 63.27, 63.05, 33.41, 16.71 and 0.72 QSE, respectively. After the coupled treatment, the removal efficiencies of M1(81%), M2(86%) were higher than M3, M4(63%, 61%). Pearson correlation analysis suggested that M1, M2 and M3 were the major contributors to the cake layer, and M4, M5 might more easily lead to pore blockages. Copyright © 2017 Elsevier B.V. All rights reserved.

Removal of Particulate Matter in a Tubular Wet Electrostatic Precipitator Using a Water Collection Electrode

PubMed Central

Kim, Jong-Ho; Yoo, Hee-Jung; Hwang, You-Seong; Kim, Hyeok-Gyu

2012-01-01

As one of the effective control devices of air pollutants, the wet electrostatic precipitator (ESP) is an effective technique to eliminate acid mist and fine particles that are re-entrained in a collection electrode. However, its collection efficiency can deteriorate, as its operation is subject to water-induced corrosion of the collection electrode. To overcome this drawback, we modified the wet ESP system with the installation of a PVC dust precipitator wherein water is supplied as a replacement of the collection electrode. With this modification, we were able to construct a compact wet ESP with a small specific collection area (SCA, 0.83 m2/(m3/min)) that can acquire a high collection efficiency of fine particles (99.7%). PMID:22577353

Spectroscopic characterization of DOM and the nitrogen removal mechanism during wastewater reclamation plant.

PubMed

Wang, Lei; Li, Ying-Jun; Xiong, Ying; Tan, Wen-Bing; Zhang, Lie-Yu; Li, Xiang; Wang, Xiao-Shu; Xu, Jian-Feng; Li, Tong-Tong; Wang, Jin-Sheng; Cai, Ming-Xuan; Xi, Bei-Dou; Wang, Di-Hua

2017-01-01

The performance of the Sha-he wastewater reclamation plant was evaluated in this study. To remove residual nitrogen after Anaerobic-Anoxic-Oxic (A2O) treatment, three multistage Anoxic-Oxic (A/O) were added to investigate the nitrogen removal efficiency and its mechanism. In addition, the constituents and evolution of dissolved organic matter (DOM) during wastewater reclamation was also investigated using a method combining fluorescence spectroscopy with fluorescence regional integration (FRI). The results suggested that multistage A/O treatment can effectively improve the nitrogen removal ability under low concentrations of carbon sources. The total nitrogen (TN) exhibits significantly positive correlation with fulvic acid-like materials and humic acid-like materials. The correlation coefficient for TN and fulvic acid-like substances (R2 = 0.810, P < 0.01) removal was greater than that of humic acid-like substances (R2 = 0.636, P < 0.05). The results indicate that nitrogen removal may be achieved with the fulvic-like and humic-like substances, and the removal effects were higher by fulvic acid-like substances than humic-like substances, mostly due to that the latter were relatively more difficult to be utilized as carbon source during the nitrogen removal process. The effluent water quality of biological treatment reached the first grade A standard of "Cities sewage treatment plant pollutant discharge standard" (GB18918-2002). In addition, the effluent from the membrane bioreactor reached the "Standards of reclaimed water quality" (SL368-2006).

Spectroscopic characterization of DOM and the nitrogen removal mechanism during wastewater reclamation plant

PubMed Central

Wang, Lei; Li, Ying-Jun; Xiong, Ying; Tan, Wen-Bing; Zhang, Lie-Yu; Li, Xiang; Wang, Xiao-Shu; Xu, Jian-feng; Li, Tong-Tong; Wang, Jin-Sheng; Cai, Ming-Xuan; Xi, Bei-Dou; Wang, Di-Hua

2017-01-01

The performance of the Sha-he wastewater reclamation plant was evaluated in this study. To remove residual nitrogen after Anaerobic-Anoxic-Oxic (A2O) treatment, three multistage Anoxic-Oxic (A/O) were added to investigate the nitrogen removal efficiency and its mechanism. In addition, the constituents and evolution of dissolved organic matter (DOM) during wastewater reclamation was also investigated using a method combining fluorescence spectroscopy with fluorescence regional integration (FRI). The results suggested that multistage A/O treatment can effectively improve the nitrogen removal ability under low concentrations of carbon sources. The total nitrogen (TN) exhibits significantly positive correlation with fulvic acid-like materials and humic acid-like materials. The correlation coefficient for TN and fulvic acid-like substances (R2 = 0.810, P < 0.01) removal was greater than that of humic acid-like substances (R2 = 0.636, P < 0.05). The results indicate that nitrogen removal may be achieved with the fulvic-like and humic-like substances, and the removal effects were higher by fulvic acid-like substances than humic-like substances, mostly due to that the latter were relatively more difficult to be utilized as carbon source during the nitrogen removal process. The effluent water quality of biological treatment reached the first grade A standard of “Cities sewage treatment plant pollutant discharge standard” (GB18918-2002). In addition, the effluent from the membrane bioreactor reached the “Standards of reclaimed water quality” (SL368-2006). PMID:29149172

Simultaneous organic matter removal and nitrification of an inert self-supporting immersed media to upgrade aerated lagoons.

PubMed

Boutet, E; Baillargeon, S; Patry, B; Lessard, P

2018-01-01

A pilot study was performed to evaluate the potential of an inert self-supported immersed fixed film media to upgrade aerated lagoons. Simultaneous organic matter removal and nitrification was assessed under different loading rates and temperatures (near 0 °C) using 12 laboratory-scale reactors operated in parallel. Test results showed that both the temperature and the load have an influence on organic matter effluent concentrations. Effluent quality seemed related to the observed biofilm thickness. Thicker biofilm is believed to have contributed to biomass detachment and increased particulate organic matter concentrations in the effluent. Simultaneous organic removal and nitrification was obtained at loads above 5 g CBOD 5 /m 2 ·d. The highest nitrification rate at 0.4 °C was obtained for the smallest load, which showed a nitrification limitation close to freezing point.

The impact of pre-oxidation with potassium permanganate on cyanobacterial organic matter removal by coagulation.

PubMed

Naceradska, Jana; Pivokonsky, Martin; Pivokonska, Lenka; Baresova, Magdalena; Henderson, Rita K; Zamyadi, Arash; Janda, Vaclav

2017-05-01

The study investigates the effect of permanganate pre-oxidation on the coagulation of peptides/proteins of Microcystis aeruginosa which comprise a major proportion of the organic matter during cyanobacterial bloom decay. Four different permanganate dosages (0.1, 0.2, 0.4 and 0.6 mg KMnO 4 mg -1 DOC) were applied prior to coagulation by ferric sulphate. Moreover, changes in sample characteristics, such as UV 254 , DOC content and molecular weight distribution, after pre-oxidation were monitored. The results showed that permanganate pre-oxidation led to a reduction in coagulant dose, increased organic matter removals by coagulation (by 5-12% depending on permanganate dose), microcystin removal (with reductions of 91-96%) and a shift of the optimum pH range from 4.3 to 6 without to 5.5-7.3 with pre-oxidation. Degradation of organic matter into inorganic carbon and adsorption of organic matter onto hydrous MnO 2 are suggested as the main processes responsible for coagulation improvement. Moreover, permanganate prevented the formation of Fe-peptide/protein complexes that inhibit coagulation at pH about 6.2 without pre-oxidation. The study showed that carefully optimized dosing of permanganate improves cyanobacterial peptide/protein removal, with the benefit of microcystin elimination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics of DO, organic matter, and ammonium profile for practical-scale DHS reactor under various organic load and temperature conditions.

PubMed

Nomoto, Naoki; Ali, Muntjeer; Jayaswal, Komal; Iguchi, Akinori; Hatamoto, Masashi; Okubo, Tsutomu; Takahashi, Masanobu; Kubota, Kengo; Tagawa, Tadashi; Uemura, Shigeki; Yamaguchi, Takashi; Harada, Hideki

2018-04-01

Profile analysis of the down-flow hanging sponge (DHS) reactor was conducted under various temperature and organic load conditions to understand the organic removal and nitrification process for sewage treatment. Under high organic load conditions (3.21-7.89 kg-COD m -3  day -1 ), dissolved oxygen (DO) on the upper layer of the reactor was affected by organic matter concentration and water temperature, and sometimes reaches around zero. Almost half of the COD Cr was removed by the first layer, which could be attributed to the adsorption of organic matter on sponge media. After the first layer, organic removal proceeded along the first-order reaction equation from the second to the fourth layers. The ammoniacal nitrogen removal ratio decreased under high organic matter concentration (above 100 mg L -1 ) and low DO (less than 1 mg L -1 ) condition. Ammoniacal nitrogen removal proceeded via a zero-order reaction equation along the reactor height. In addition, the profile results of DO, COD Cr , and NH 3 -N were different in the horizontal direction. Thus, it is thought the concentration of these items and microbial activities were not in a uniform state even in the same sponge layer of the DHS reactor.

Silica-coated magnetite nanoparticles core-shell spheres (Fe3O4@SiO2) for natural organic matter removal.

PubMed

Karimi Pasandideh, Elahe; Kakavandi, Babak; Nasseri, Simin; Mahvi, Amir Hossein; Nabizadeh, Ramin; Esrafili, Ali; Rezaei Kalantary, Roshanak

2016-01-01

In this work, the magnetite (Fe 3 O 4 ) nanoparticles (MNPs) and silica-coated magnetite nanoparticles (SMNPs) were synthesized as adsorbents for removing humic acid (HA) from water resources. The adsorption processes were performed in batch experiments with which the influence of pH, reaction time, adsorbent dosage, initial concentrations of HA and temperature were investigated. Specific techniques were applied to characterize the features of both adsorbents (i. e. TECHNIQUES) (SEM, XRD, TEM, BET, EDX and VSM). The maximum saturation magnetization for SMNPs was 30.2 emu/g, which made its separation from the solution by a magnetic field to be easier and faster. The HA adsorption process onto the both adsorbents were best described by the Freundlich isotherm and pseudo-second-order kinetic models. Highest adsorption efficiency of HA by MNPs an d SMNPs occurred at acidic conditions (pH ≈ 3). The mechanisms of adsorption process involved with a physisorption process such as (i. e. hydrogen bonding and electrostatic interaction). The predicted maximum monolayer adsorption capacities obtained by Langmuir isotherm model for MNPs and SMNPs were 96.15 and 196.07 mg/g, respectively. Higher amount of HA adsorption onto the surfaces of SMNPs than MNPs surfaces was observed, reflecting that silica impregnated on MNPs enhances the efficiency of the adsorbent in removing HA.

A novel technique of semi-aerobic aged refuse biofilter for leachate treatment.

PubMed

Han, Zhi-Yong; Liu, Dan; Li, Qi-Bin; Li, Gui-Zhi; Yin, Zhao-Yang; Chen, Xin; Chen, Jian-Nan

2011-08-01

We developed a semi-aerobic aged refuse biofilter (SAARB) for leachate treatment and examined its advantages and disadvantages compared to previous aged refuse biofilters (ARBs). To assess its treatment capability, decontamination mechanisms and optimal performance parameters, a single-period experiment and L(9)(3(4)) orthogonal array design experiments were conducted on artificial leachate. The SAARB markedly enhanced the treatment capability and removal efficiency of organic matter and nitrogen pollutants due to the alternating aerobic-anoxic-anaerobic zones in situ. The reduction in chemical oxygen demand (COD), ammonia nitrogen (NH(4)(+)-N) and total nitrogen (TN) exceeded 98%, 94%, and 80%, respectively. After the leachate was distributed onto the SAARB surface, the effluent velocity decreased as a logarithmic function, and there was a concomitant reduction in leachate effluent volume. Based on the capacity for removal of COD, NH(4)(+)-N, and TN, the effective height of aged refuse in a SAARB was enough to be 900mm. An excellent treatment efficiency could be achieved at 20-35°C, with a leachate distribution time of 1h once every period of 2-3 days, hydraulic loading of 11-30L/(m(3)day), and COD loading of 550-1200g/(m(3)day). This new SAARB system demonstrates superior efficacy for biofilter compared to other ARB systems, especially for nitrogen removal from leachate. Copyright © 2011 Elsevier Ltd. All rights reserved.

Winery wastewater treatment by combination of Cryptococcus laurentii and Fenton's reagent.

PubMed

Santos, Cátia; Lucas, Marco S; Dias, Albino A; Bezerra, Rui M F; Peres, José A; Sampaio, Ana

2014-12-01

Winery wastewaters (WW) have high levels of organic matter, resulting in high COD and BOD and suspended solids. This paper studies the combination of biological and chemical processes in WW treatment. Among 10 yeast isolates, Filobasidium sp. (AGG 577) and Cryptococcus laurentii (AGG 726) were selected due to their superior performance in COD removal. During WW degradation, COD and total polyphenols (TPP) content removal of 89-90% for Filobasidium sp. and 90-93% for C. laurentii were obtained. However, despite similar degradation efficiency for both yeasts, COD kinetics and pH evolution during treatment reveals that C. laurentii presents a faster response than Filobasidium sp. The toxicity (inhibition of Vibrio fischeri luminescence) of C. laurentii treated WW decreases to an inhibition value below 2.5%. However, treated WW exceeds the legal limits, making necessary an additional treatment. In this case, the selection of Fenton's reagent as a chemical final polish step process is a good compromise between efficiency and lower practical complexity. The best results for both COD and TPP removal were obtained with H2O2 initial concentration of 39.2mM and a H2O2:Fe(2+) molar ratio of 15:1. The combined C. laurentii - Fenton's reagent treatment of WW achieved a total reduction of 98% and 96%, for COD and TPP, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Leachate/domestic wastewater aerobic co-treatment: A pilot-scale study using multivariate analysis.

PubMed

Ferraz, F M; Bruni, A T; Povinelli, J; Vieira, E M

2016-01-15

Multivariate analysis was used to identify the variables affecting the performance of pilot-scale activated sludge (AS) reactors treating old leachate from a landfill and from domestic wastewater. Raw leachate was pre-treated using air stripping to partially remove the total ammoniacal nitrogen (TAN). The control AS reactor (AS-0%) was loaded only with domestic wastewater, whereas the other reactor was loaded with mixtures containing leachate at volumetric ratios of 2 and 5%. The best removal efficiencies were obtained for a ratio of 2%, as follows: 70 ± 4% for total suspended solids (TSS), 70 ± 3% for soluble chemical oxygen demand (SCOD), 70 ± 4% for dissolved organic carbon (DOC), and 51 ± 9% for the leachate slowly biodegradable organic matter (SBOM). Fourier transform infrared (FTIR) spectroscopic analysis confirmed that most of the SBOM was removed by partial biodegradation rather than dilution or adsorption of organics in the sludge. Nitrification was approximately 80% in the AS-0% and AS-2% reactors. No significant accumulation of heavy metals was observed for any of the tested volumetric ratios. Principal component analysis (PCA) and partial least squares (PLS) indicated that the data dimension could be reduced and that TAN, SCOD, DOC and nitrification efficiency were the main variables that affected the performance of the AS reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Global pulses of organic carbon burial in deep-sea sediments during glacial maxima

PubMed Central

Cartapanis, Olivier; Bianchi, Daniele; Jaccard, Samuel L.; Galbraith, Eric D.

2016-01-01

The burial of organic carbon in marine sediments removes carbon dioxide from the ocean–atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we show that the accumulation rate of organic carbon in the deep sea was consistently higher (50%) during glacial maxima than during interglacials. The spatial pattern and temporal progression of the changes suggest that enhanced nutrient supply to parts of the surface ocean contributed to the glacial burial pulses, with likely additional contributions from more efficient transfer of organic matter to the deep sea and better preservation of organic matter due to reduced oxygen exposure. These results demonstrate a pronounced climate sensitivity for this global carbon cycle sink. PMID:26923945

Enhancing biomethanogenic treatment of fresh incineration leachate using single chambered microbial electrolysis cells.

PubMed

Gao, Yan; Sun, Dezhi; Dang, Yan; Lei, Yuqing; Ji, Jiayang; Lv, Tingwei; Bian, Rui; Xiao, Zhihui; Yan, Liangming; Holmes, Dawn E

2017-05-01

Methanogenic treatment of municipal solid waste (MSW) incineration leachate can be hindered by high concentrations of refractory organic matter and humification of compounds in the leachate. In an attempt to overcome some of these impediments, microbial electrolysis cells (MECs) were incorporated into anaerobic digesters (ADMECs). COD removal efficiencies and methane production were 8.7% and 44.3% higher in ADMECs than in controls, and ADMEC reactors recovered more readily from souring caused by high organic loading rates. The degradation rate of large macromolecules was substantially higher (96% vs 81%) in ADMEC than control effluent, suggesting that MECs stimulated degradation of refractory organic matter and reduced humification. Exoelectrogenic bacteria and microorganisms known to form syntrophic partnerships were enriched in ADMECs. These results show that ADMECs were more effective at treatment of MSW incineration leachate, and should be taken into consideration when designing future treatment facilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

New limits on primordial black hole dark matter from an analysis of Kepler source microlensing data.

PubMed

Griest, Kim; Cieplak, Agnieszka M; Lehner, Matthew J

2013-11-01

We present new limits on the allowed masses of a dark matter (DM) halo consisting of primordial black holes (PBH) (or any other massive compact halo object). We analyze two years of data from the Kepler satellite, searching for short-duration bumps caused by gravitational microlensing. After removing background events consisting of variable stars, flare events, and comets or asteroids moving through the Kepler field, we find no microlensing candidates. We measure the efficiency of our selection criteria by adding millions of simulated microlensing lensing events into the Kepler light curves. We find that PBH DM with masses in the range 2 × 10(-9) M[Symbol: see text] to 10(-7)M[Symbol: see text] cannot make up the entirety of the DM in the Milky Way. At the low-mass end, this decreases the allowed mass range by more than an order of magnititude.

Ultrasonically assisted extraction of calcium and ash from char

NASA Astrophysics Data System (ADS)

Mathumba, E. E.; Mbaya, R. K. K.; Kolesnikov, A.

2018-03-01

This study characterized and removed calcium and ash content from char to improve the chemical quality of char as reductant for titanium smelting application. Calcium in char can be classified in two parts: mineral matter and cationic metals associated with organic matrix. Virgin and chemically treated char was characterized by using ISO 1171, wet chemistry methods, ISO 19579, XRF, and B.E.T. methods. In this present work, demineralization of char with mild chemical leachants such as acetic acid, citric acid, gluconic acid and Ethylene Diamine Tetra Acetic acid with three different ultrasonic power input (150 W, 270 W and 300 W) and semi-dual frequency of 40 kHz tank was investigated. Actual power dissipated into the system was calculated from the calorimetric measurement. An optimum set of process parameters are identified and validated. The ultrasound technology was compared with soaking technology to determine the efficiency of ultrasound system for the removal of calcium. The removal of calcium was exponentially higher with ultrasonic treatment than without it. Results revealed that mild chemical reagents do not harm the carbon content of char. It is evident from the results that amongst the leachants used; acetic and citric acid has caused significant removal of mineral phases.

Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.

PubMed

Hahladakis, John N; Lekkas, Nikolaos; Smponias, Andreas; Gidarakos, Evangelos

2014-06-01

This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants. Copyright © 2013 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson III, David J.; Sulzberger, Barbara; Zepp, Richard G.

Climate change modulates the effects of solar UV radiation on biogeochemical cycles in terrestrial and aquatic ecosystems, particularly for carbon cycling, resulting in UV-mediated positive or negative feedbacks on climate. Possible positive feedbacks discussed in this assessment include: (i) enhanced UV-induced mineralisation of above ground litter due to aridification; (ii) enhanced UV-induced mineralisation of photoreactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting; (iii) reduced efficiency of the biological pump due to UV-induced bleaching of coloured dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solarmore » UV-B radiation. Mineralisation of organic matter results in the production and release of CO 2, whereas the biological pump is the main biological process for CO 2 removal by aquatic ecosystems. This research also assesses the interactive effects of solar UV radiation and climate change on the biogeochemical cycling of aerosols and trace gases other than CO 2, as well as of chemical and biological contaminants. Lastly,, interacting effects of solar UV radiation and climate change on biogeochemical cycles are particularly pronounced at terrestrial-aquatic interfaces.« less

Similar PAH Fate in Anaerobic Digesters Inoculated with Three Microbial Communities Accumulating Either Volatile Fatty Acids or Methane

PubMed Central

Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

2015-01-01

Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10 % to 30 %, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal depends on the molecule type and on the solid matter removal. But, as PAH elimination is similar whether the solid substrate is degraded into VFA or into methane, it seems that the fermentative communities are responsible for their elimination. PMID:25874750

Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

PubMed

Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

2015-01-01

Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal depends on the molecule type and on the solid matter removal. But, as PAH elimination is similar whether the solid substrate is degraded into VFA or into methane, it seems that the fermentative communities are responsible for their elimination.

Effects of organic matter removal, soil compaction, and vegetation control on Collembolan populations

Treesearch

Robert J. Eaton; Mary Barbercheck; William D. Smith

2004-01-01

Collembola can be among the most numerous meso-invertebrates in the forest floor and, through their interaction with primary decomposers in the decomposition food web, may affect litter decomposition and consequently site productivity. This study was conducted to determine whether Collembolan abundance could be impacted by organic matter removal, compaction, and...

Tar-free fuel gas production from high temperature pyrolysis of sewage sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Leguan; Xiao, Bo; Hu, Zhiquan

2014-01-15

Highlights: • High temperature pyrolysis of sewage sludge was efficient for producing tar-free fuel gas. • Complete tar removal and volatile matter release were at elevated temperature of 1300 °C. • Sewage sludge was converted to residual solid with high ash content. • 72.60% of energy conversion efficiency for gas production in high temperature pyrolysis. • Investment and costing for tar cleaning were reduced. - Abstract: Pyrolysis of sewage sludge was studied in a free-fall reactor at 1000–1400 °C. The results showed that the volatile matter in the sludge could be completely released to gaseous product at 1300 °C. Themore » high temperature was in favor of H{sub 2} and CO in the produced gas. However, the low heating value (LHV) of the gas decreased from 15.68 MJ/N m{sup 3} to 9.10 MJ/N m{sup 3} with temperature increasing from 1000 °C to 1400 °C. The obtained residual solid was characterized by high ash content. The energy balance indicated that the most heating value in the sludge was in the gaseous product.« less

Method of treating waste water

DOEpatents

Deininger, J. Paul; Chatfield, Linda K.

1991-01-01

A process of treating water to remove transuranic elements contained therein by adjusting the pH of a transuranic element-containing water source to within the range of about 6.5 to about 14.0, admixing the water source with an alkali or alkaline earth ferrate in an amount sufficient to form a precipitate within the water source, the amount of ferrate effective to reduce the transuranic element concentration in the water source, permitting the precipitate in the admixture to separate and thereby yield a supernatant liquid having a reduced transuranic element concentration, and separating the supernatant liquid having the reduced transuranic element concentration from the admixture is provided. Additionally, a water soluble salt, e.g., a zirconium salt, can be added with the alkali or alkaline earth ferrate in the process to provide greater removal efficiencies. A composition of matter including an alkali or alkaline earth ferrate and a water soluble salt, e.g., a zirconium salt, is also provided.

Characterization of solidifiers used for oil spill remediation.

PubMed

Sundaravadivelu, Devi; Suidan, Makram T; Venosa, Albert D; Rosales, Pablo I

2016-02-01

The physical characteristics and chemical composition of oil spill solidifiers were studied, and correlation of these properties with product effectiveness enabled determination of characteristics that are desirable in a good solidifier. The analyses revealed that the commercial products were primarily comprised of organic polymers and a few trace elements. A natural sorbent, which was composed entirely of plant based matter, was also evaluated, and it had the highest oil removal capacity, but it did not produce a solid mat-like final product. Generally, solidifiers with a carbonate group, pore size greater than 5 μm, and bulk densities lower than 0.3 g cm(-3) were found to have better efficiency and produced a cohesive rubbery final product that facilitated removal compared to sorbents. The importance of bulk density and pore size in the performance of the solidifier suggest that the primary mechanism of action was likely physical sorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance evaluation of startup for a yeast membrane bioreactor (MBRy) treating landfill leachate.

PubMed

Amaral, Míriam C S; Gomes, Rosimeire F; Brasil, Yara L; Oliveira, Sílvia M A; Moravia, Wagner G

2017-12-06

The startup process of a membrane bioreactor inoculated with yeast biomass (Saccharomyces cerevisiae) and used in the treatment of landfill leachate was evaluated. The yeast membrane bioreactor (MBRy) was inoculated with an exogenous inoculum, a granulated active dry commercial bakers' yeast. The MBRy was successfully started up with a progressive increase in the landfill leachate percentage in the MBRy feed and the use of Sabouraud Dextrose Broth. The membrane plays an important role in the startup phase because of its full biomass retention and removal of organic matter. MBRy is a suitable and promising process to treat recalcitrant landfill leachate. After the acclimation period, the COD and NH 3 removal efficiency reached values of 72 ± 3% and 39 ± 2% respectively. MBRy shows a low membrane-fouling potential. The membrane fouling was influenced by soluble microbial products, extracellular polymeric substances, sludge particle size, and colloidal dissolved organic carbon.

Influence of sludge reflux ratios on biodegradation performance in a coupled landfill leachate treatment process based on UASB and submerged MBR.

PubMed

Wang, Bing; Li, Wei; Liu, Lei; Huang, Guo He

2016-07-28

This study was undertaken to investigate the effects of different sludge reflux ratios (SRRs) on the overall performance and the fouling behavior of the up-flow anaerobic sludge blanket (UASB) reactor-anoxic-membrane bioreactor (MBR). The leachate and synthetic municipal wastewater were mixed in order to improve the biodegradability of the old leachate. Results showed that excellent removal efficiencies for chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) were obtained by using the integrated UASB-anoxic-MBR process. The average COD removals were 91.01%, 93.90%, and 92.67% and that of NH3-N were 98.1%, 98.5%, and 98.9% when SRRs were 100%, 300%, and 500%, respectively. The study of the membrane fouling mechanism indicated that proteins, hydrocarbons and inorganic matter are the main elements of the cake layers.

Co-biodrying of sewage sludge and organic fraction of municipal solid waste: Role of mixing proportions.

PubMed

Zhang, Difang; Luo, Wenhai; Yuan, Jing; Li, Guoxue

2018-04-26

This study investigated the performance of co-biodrying sewage sludge and organic fraction of municipal solid waste (OFMSW) at different proportions. Cornstalk was added at 15% (of total wet weight) as the bulking agent. Results show that increasing OFMSW percentage promoted the biodegradation of organic matter, thus enhancing the temperature integration value and water removal to above 75% during sludge and OFMSW co-biodrying. In particular, adding more OFMSW accelerated the biodegradation of soluble carbohydrates, lignins, lipids, and amylums, resulting in more organic loss and thus lower biodrying index (3.3-3.7 for 55-85% OFMSW). Water balance calculation indicated that evaporation was the main mechanism for water removal. Heat used for water evaporation was 37.7-48.6% of total heat consumption during co-biodrying. Our results suggest that sludge and OFMSW should be mixed equally for their efficient co-biodrying. Copyright © 2018 Elsevier Ltd. All rights reserved.

[The remove characteristics of dissolved organic matter in landfill leachate during the treatment process].

PubMed

He, Xiao-Song; Yu, Jing; Xi, Bei-Dou; Jiang, Yong-Hai; Zhang, Jin-Bao; Li, Dan; Pan, Hong-Wei; Liu, Hong-Liang

2012-09-01

In order to investigate remove characteristics of dissolved organic matter in landfill leachate, leachates were sampled during the process (i. e. , adjusting tank, anaerobic zone, oxidation ditch and MBR processing). Dissolved organic matter was extracted and its content and structure were characterized by fluorescence excitation-emission matrix spectra, UV-Vis specrtra and FTIR spectra. The results showed that an amount of 377.6 mg x L(-1) dissolved organic carbon (DOC) was removed during the whole treatment process, and the total removal rate was up to 78.34%. The 25.56% of DOC in the adjusting tank was removed during the anaerobic zone, 41.58% of DOC in anaerobic effluent was removed during the oxidation ditch, while 50.19% of DOC in the oxidation ditch effluent decreased in the MBR process. The anaerobic process increased the content of unsaturated compound and polysaccharides in leachate DOM, which improved the leachate biochemical characteristics. The unsaturated compound and polysaccharides were removed effectively during being in oxidation ditch. Protein-like and humic-like fluorescence peaks were observed in the adjusting tank and anaerobic zone, while humic-like fluorescence peaks were just presented in the oxidation ditch and MBR processing. Protein-like and fulvic-like substances were biodegraded in the adjusting tank and anaerobic zone, while humic-like materials were removed in the MBR process.

Impact of natural organic matter properties on the kinetics of suspended ion exchange process.

PubMed

Bazri, Mohammad Mahdi; Mohseni, Madjid

2016-03-15

Removal kinetics of four standard organic matter isolates under the application of strongly basic ion exchange resins (IEX) in suspended mode was studied under commercial application conditions. Suwannee River natural organic matter (SRNOM), SR fulvic acid (SRFA), and Pony Lake fulvic acid (PLFA) were greatly removed (>90%) and highly preferred by IEX resins (α > 5, over Cl(-), and HCO3(-)) while SR humic acid (SRHA) was the least preferred organic structure among the four isolates studied (α ≈ 1). Moreover, the efficacy of removal for fulvic acids (i.e., SRFA, PLFA) was consistent over consecutive reuse of IEX resins (i.e., loading cycles) whereas it decreased for SRNOM and SRHA over the course of operation. The stoichiometric correlation between the chloride released from the resins as a result of organic molecules uptake indicated that ion exchange was the dominant mechanism. Results obtained indicated that molecular weight and charge density of isolates played a major role in the performance of ion exchange process for organic matter removal. Furthermore, various empirical and physical models were evaluated using the experimental data and pore diffusion was found to be the rate-liming step during the uptake of organic matters; hence, it was used as the appropriate model to predict the kinetics of removal. Consequently, free liquid diffusivities and effective pore diffusion coefficients of organic molecules were estimated and findings were in agreement with the literature data that were obtained from spectrophotometric methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of sodium carbonate-oxygen and sodium hydroxide-oxygen pretreatments on the chemical composition and enzymatic saccharification of wheat straw.

PubMed

Geng, Wenhui; Huang, Ting; Jin, Yongcan; Song, Junlong; Chang, Hou-Min; Jameel, Hasan

2014-06-01

Pretreatment of wheat straw with a combination of sodium carbonate (Na2CO3) or sodium hydroxide (NaOH) with oxygen (O2) 0.5MPa was evaluated for its delignification ability at relatively low temperature 110°C and for its effect on enzymatic hydrolysis efficiency. In the pretreatment, the increase of alkali charge (as Na2O) up to 12% for Na2CO3 and 6% for NaOH, respectively, resulted in enhancement of lignin removal, but did not significantly degrade cellulose and hemicellulose. When the pretreated solid was hydrolyzed with a mixture of cellulases and hemicellulases, the sugar yield increased rapidly with the lignin removal during the pretreatment. A total sugar yield based on dry matter of raw material, 63.8% for Na2CO3-O2 and 71.9% for NaOH-O2 was achieved under a cellulase loading of 20FPU/g-cellulose. The delignification efficiency and total sugar yield from enzymatic hydrolysis were comparable to the previously reported results at much higher temperature without oxygen. Copyright © 2014 Elsevier Ltd. All rights reserved.

Greywater as a sustainable water source: A photocatalytic treatment technology under artificial and solar illumination.

PubMed

Tsoumachidou, Sophia; Velegraki, Theodora; Antoniadis, Apostolos; Poulios, Ioannis

2017-06-15

Greywater considers being a highly reclaimable water source particularly important for water-stressed nations. In this work, heterogeneous photocatalysis using artificial and solar illumination has been applied for the mineralization of simulated light greywater (effluents from dishwashers and kitchen sinks were excluded from the study). The effects on the process' efficiency of TiO 2 P25 catalyst's concentration, initial concentration of H 2 O 2 and Fe 3+ , pH of the solution, as well as the type of radiation, were evaluated in a bench-scale Pyrex reactor and a pilot-scale slurry fountain photoreactor. The treatment efficiency has been followed through the evolution of the organic matter content expresses as dissolved organic carbon (DOC). Best results were obtained with the photo-Fenton-assisted TiO 2 photocatalytic process with 72% DOC removal after 210 min of bench scale treatment, while under the same photocatalytic conditions in the pilot reactor the DOC removal reached almost 64%. Moreover, the decrease in toxicity, phytotoxicity and biodegradability of the simulated wastewater has been observed after solar-induced photocatalytic treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of organic impurities in waste glycerol from biodiesel production process through the acidification and coagulation processes.

PubMed

Xie, Qiao-Guang; Taweepreda, Wirach; Musikavong, Charongpun; Suksaroj, Chaisri

2012-01-01

Treatment of waste glycerol, a by-product of the biodiesel production process, can reduce water pollution and bring significant economic benefits for biodiesel facilities. In the present study, hydrochloric acid (HCl) was used as acidification to convert soaps into salts and free fatty acids which were recovered after treatment. The pH value, dosages of polyaluminum chloride (PACl) and dosage of polyacrylamide (PAM) were considered to be the factors that can influence coagulation efficiency. The pH value of waste glycerol was adjusted to a pH range of 3-9. The PACl and PAM added were in the range of 1-6 g/L and 0.005-0.07 g/L. The results showed best coagulation efficiency occurs at pH 4 when dosage of PACl and PAM were 2 and 0.01 g/L. The removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD(5)), total suspended solids (TSS) and soaps were 80, 68, 97 and 100%, respectively. The compositions of organic matters in the treated waste glycerol were glycerol (288 g/L), methanol (3.8 g/L), and other impurities (0.3 g/L).

Ablation dynamics - from absorption to heat accumulation/ultra-fast laser matter interaction

NASA Astrophysics Data System (ADS)

Kramer, Thorsten; Remund, Stefan; Jäggi, Beat; Schmid, Marc; Neuenschwander, Beat

2018-05-01

Ultra-short laser radiation is used in manifold industrial applications today. Although state-of-the-art laser sources are providing an average power of 10-100 W with repetition rates of up to several megahertz, most applications do not benefit from it. On the one hand, the processing speed is limited to some hundred millimeters per second by the dynamics of mechanical axes or galvanometric scanners. On the other hand, high repetition rates require consideration of new physical effects such as heat accumulation and shielding that might reduce the process efficiency. For ablation processes, process efficiency can be expressed by the specific removal rate, ablated volume per time, and average power. The analysis of the specific removal rate for different laser parameters, like average power, repetition rate or pulse duration, and process parameters, like scanning speed or material, can be used to find the best operation point for microprocessing applications. Analytical models and molecular dynamics simulations based on the so-called two-temperature model reveal the causes for the appearance of limiting physical effects. The findings of models and simulations can be used to take advantage and optimize processing strategies.

Forest Soil Productivity on the Southern Long-Term Soil Productivity Sites at Age 5

Treesearch

D. Andrew Scott; Allan E. Tiarks; Felipe G. Sanchez; Michael Elliott-Smith; Rick Stagg

2004-01-01

Forest management operations have the potential to reduce soil productivity through organic matter and nutrient removal and soil compaction. We measured pine volume, bulk density, and soil and foliar nitrogen and phosphorus at age 5 on the 13 southern Long-Term Soil Productivity study sites. The treatments were organic matter removal [bole only (BO), whole tree (WT),...

Simultaneous chemical oxygen demand removal, methane production and heavy metal precipitation in the biological treatment of landfill leachate using acid mine drainage as sulfate resource.

PubMed

Li, Yu-Long; Wang, Jin; Yue, Zheng-Bo; Tao, Wei; Yang, Hai-Bin; Zhou, Yue-Fei; Chen, Tian-Hu

2017-07-01

Biological treatment played an important role in the treatment of landfill leachate. In the current study, acid mine drainage (AMD) was used as a source of sulfate to strengthen the anaerobic treatment of landfill leachate. Effects of chemical oxygen demand (COD) and SO 4 2- mass concentration ratio on the decomposition of organic matter, methane production and sulfate reduction were investigated and the microbial community was analyzed using the high throughout methods. Results showed that high removal efficiency of COD, methane production and heavy metal removal was achieved when the initial COD/SO 4 2- ratio (based on mass) was set at 3.0. The relative abundance of anaerobic hydrogen-producing bacteria (Candidatus Cloacamonas) in the experimental group with the addition of AMD was significantly increased compared to the control. Abundance of hydrogenotrophic methanogens of Methanosarcina and Methanomassiliicoccus was increased. Results confirmed that AMD could be used as sulfate resource to strengthen the biological treatment of landfill leachate. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Ozone disintegration of excess biomass and application to nitrogen removal.

PubMed

Park, Ki Young; Lee, Jae Woo; Ahn, Kyu-Hong; Maeng, Sung Kyu; Hwang, Jong Hyuk; Song, Kyung-Guen

2004-01-01

A pilot-scale facility integrated with an ozonation unit was built to investigate the feasibility of using ozone-disintegration byproducts of wasted biomass as a carbon source for denitrification. Ozonation of biomass resulted in mass reduction by mineralization as well as by ozone-disintegrated biosolids recycling. Approximately 50% of wasted solids were recovered as available organic matter (ozonolysate), which included nonsettleable microparticles and soluble fractions. Microparticles were observed in abundance at relatively low levels of ozone doses, while soluble fractions became dominant at higher levels of ozone doses in ozone-disintegrated organics. Batch denitrification experiments showed that the ozonolysate could be used as a carbon source with a maximum denitrification rate of 3.66 mg nitrogen (N)/g volatile suspended solids (VSS) x h. Ozonolysate was also proven to enhance total nitrogen removal efficiency in the pilot-scale treatment facility. An optimal chemical oxygen demand (COD)-to-nitrogen ratio for complete denitrification was estimated as 5.13 g COD/g N. The nitrogen-removal performance of the modified intermittently decanted extended aeration process dependent on an external carbon supply could be described as a function of solids retention time.

Cyclone as a precleaner to ESP--a need for Indian coal based thermal power plants.

PubMed

George, K V; Manjunath, S; Rao, C V Chalapati; Bopche, A M

2003-11-01

Almost all coal based thermal power plants (CTPP) in India use electrostatic precipitator (ESP) for reduction of particulate matter (PM) in flue gas generated due to the combustion of Indian coal. This coal is characterized by high ash content, low calorific value and low sulfur content resulting in the generation of a very large amount of highly electrically-resistive fly-ash; thereby requiring a very large size ESP to minimize the fly-ash emissions. However, the flue-gas particle size distribution analysis showed that 60% of the particles are above 15 microm size, which can be conveniently removed using a low-cost inertial separator such as a cyclone separator. It is proposed that a cyclone be used, as a pre-cleaner to ESP so that the large size fraction of fly-ash can be removed in the pre-cleaning and the remaining flue-gas entering the ESP will then contain only small size particles with low dust loading, thereby requiring a small ESP, and improving overall efficiency of dust removal. A low efficiency (65%), high throughput cyclone is considered for pre-cleaning flue gas and the ESP is designed for removal of the remaining 35% fly-ash from the flue gas. It is observed that with 100% dust load, the ESP requires six fields per pass, whereas with cyclone as a pre-cleaner, it requires only five fields per pass. Introducing cyclone into the flue gas path results in additional head loss, which needs to be overcome by providing additional power to induced draft (ID) fan. The permissible head loss due to the cyclone is estimated by comparing the power requirement in the bag filter control unit and cyclone-ESP combined unit. It is estimated that a head loss of 10 cm of water can be permitted across the cyclone so as to design the same for 65% efficiency.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Hydrodynamic efficiency of laser-induced transfer of matter

NASA Astrophysics Data System (ADS)

Isakov, Vladimir A.; Kanavin, Andrey P.; Nasibov, A. S.

2007-04-01

A one-dimensional analytic hydrodynamic model of the direct laser-induced transfer of matter is considered. The efficiency of pulsed laser radiation energy conversion to the kinetic energy of the ejected matter is determined. It is shown that the hydrodynamic efficiency of the process for the layers of matter of thickness exceeding the laser radiation absorption depth is determined by the adiabatic index of the evaporated matter.

Improvement of dry matter digestibility of water hyacinth by solid state fermentation using white rot fungi.

PubMed

Mukherjee, R; Ghosh, M; Nandi, B

2004-08-01

Feeding value of water hyacinth biomass colonized by three species of white rot fungi during solid-state fermentation was investigated. All three organisms proved to be efficient degraders and enhanced dry matter digestibility. Loss of organic matter was maximum (23.6+/-0.1% dry wt) after 48 days by P. ostreatus. C. indica showed maximum cellulose degradation (18.5+/-0.1% dry wt) than other two fungi after 48 days of incubation. In all cases, an extensive removal of hemicellulose at the initial growth period and a delayed degradation of lignin were observed. Hemicellulolysis was maximum (46.3+/-0.1% dry wt) by C. indica, but delignification (14.2+/-0.2% dry wt) by P. sajor-caju after 48 days. The amount of reducing sugar in the degraded biomass decreased at early stages, but increased as degradation progressed in all three cases (maximum 1.1+/-0.05% dry wt after 48 days by C. indica). Soluble nitrogen content increased only during 16-32 days of incubation (highest 1.1+/-0.1% dry wt after 32 days by P. sajor-caju). Crude protein of the bioconverted biomass increased gradually up to 32 days but decreased thereafter (maximum 10.3+/-0.1% dry wt after 32 days by P. sajor - caju). Per cent change in in vitro dry matter digestibility of degraded substrates enhanced gradually after 8 days and reached maximum after 32 days but thereafter decreased (highest + 20.4+/-0.3% dry wt by P. sajor-caju). The results demonstrated the efficient degrading capacity of the test fungi and their potential use in conversion of water hyacinth biomass into mycoprotein-rich ruminant feed, more so by P. sajor-caju.

Application of chemical oxidation to remediate HCH-contaminated soil under batch and flow through conditions.

PubMed

Usman, Muhammad; Tascone, Oriane; Rybnikova, Victoria; Faure, Pierre; Hanna, Khalil

2017-06-01

This is the first study describing the chemical oxidation of hexachlorocyclohexanes (HCHs) in contaminated soil under water saturated and unsaturated flow through conditions. Soil contaminated with β-HCH (45 mg kg -1 ) and γ-HCH (lindane, 25 mg kg -1 ) was sampled from former lindane waste storage site. Efficiency of following treatments was tested at circumneutral pH: H 2 O 2 alone, H 2 O 2 /Fe II , Na 2 S 2 O 8 alone, Na 2 S 2 O 8 /Fe II , and KMnO 4 . Experimental conditions (oxidant dose, liquid/solid ratio, and soil granulometry) were first optimized in batch experiments. Obtained results revealed that increasing dose of H 2 O 2 improved the oxidation efficiency while in Na 2 S 2 O 8 system, maximum HCHs were removed at 300 mM. However, oxidation efficiency was slightly improved by Fe II -activation. Increasing the solid/liquid ratio decreased HCH removal in soil samples crushed to 500 μm while an opposite trend was observed for 2-mm samples. Dynamic column experiments showed that oxidation efficiency followed the order KMnO 4  > Na 2 S 2 O 8 /Fe II  > Na 2 S 2 O 8 whatever the flow condition, whereas the removal extent declined at higher flow rate (e.g., ~50% by KMnO 4 at 0.5 mL/min as compared to ~30% at 2 mL/min). Both HCH removal and oxidant decomposition extents were found higher in saturated columns than the unsaturated ones. While no significant change in relative abundance of soil mineral constituents was observed before and after chemical oxidation, more than 60% of extractable organic matter was lost after chemical oxidation, thereby underscoring the non-selective behavior of chemical oxidation in soil. Due to the complexity of soil system, chemical oxidation has rarely been reported under flow through conditions, and therefore our findings will have promising implications in developing remediation techniques under dynamic conditions closer to field applications.

Characterization of a Regenerable Impactor Filter for Spacecraft Cabin Applications

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2015-01-01

Regenerable filters will play an important role in human exploration beyond low-Earth orbit. Life Support Systems aboard crewed spacecrafts will have to operate reliably and with little maintenance over periods of more than a year, even multiple years. Air filters are a key component of spacecraft life support systems, but they often require frequent routine maintenance. Bacterial filters aboard the International Space Station require almost weekly cleaning of the pre-filter screen to remove large lint debris captured in the microgravity environment. The source of the airborne matter which is collected on the filter screen is typically from clothing fibers, biological matter (hair, skin, nails, etc.) and material wear. Clearly a need for low maintenance filters requiring little to no crew intervention will be vital to the success of the mission. An impactor filter is being developed and tested to address this need. This filter captures large particle matter through inertial separation and impaction methods on collection surfaces, which can be automatically cleaned after they become heavily loaded. The impactor filter can serve as a pre-filter to augment the life of higher efficiency filters that capture fine and ultrafine particles. A prototype of the filter is being tested at the Particulate Filtration Laboratory at NASA Glenn Research Center to determine performance characteristics, including particle cut size and overall efficiency. Model results are presented for the flow characteristics near the orifice plate through which the particle-laden flow is accelerated as well as around the collection bands.

Soft drink wastewater treatment by electrocoagulation-electrooxidation processes.

PubMed

Linares Hernández, Ivonne; Barrera Díaz, Carlos; Valdés Cerecero, Mario; Almazán Sánchez, Perla Tatiana; Castañeda Juárez, Monserrat; Lugo Lugo, Violeta

2017-02-01

The aim of this work was to implement a coupled system, a monopolar Electrocoagulation (EC)-Electrooxidation (EO) processes, for the treatment of soft drink wastewater. For the EC test, Cu-Cu, anode-cathode were used at current densities of 17, 51 and 68 mA cm -2 . Only 37.67% of chemical oxygen demand (COD) and 27% of total organic carbon (TOC) were removed at 20 min with an optimum pH of 8, this low efficiency can be associated with the high concentration of inorganic ions which inhibit the oxidation of organic matter due to their complexation with copper ions. Later EO treatment was performed with boron-doped diamond-Cu electrodes and a current density of 30 Am -2 . The coupled EC-EO system was efficient to reduce organic pollutants from initial values of 1875 mg L -1 TOC and 4300 mg L -1 COD, the removal efficiencies were 75% and 85%, respectively. Electric energy consumption to degrade a kilogram of a pollutant in the soft drink wastewater using EC was 3.19 kWh kg -1 TOC and 6.66 kWh kg -1 COD. It was concluded that the coupled system EC-EO was effective for the soft drink wastewater treatment, reducing operating costs and residence time, and allowing its reuse in indirect contact with humans, thus contributing to the sustainable reuse as an effluent of industrial wastewater.

Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts

USGS Publications Warehouse

Henneberry, Y.K.; Kraus, T.E.C.; Fleck, J.A.; Krabbenhoft, D.P.; Bachand, P.M.; Horwath, W.R.

2011-01-01

The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal hydroxides. Previous research indicated coagulants were not effective at removing Hg from solution; however these studies used high concentrations of Hg and did not reflect naturally occurring concentrations of Hg. In this study, water collected from an agricultural drain in the Sacramento-San Joaquin Delta was filtered to isolate the dissolved organic matter (DOM) fraction. The DOM was then treated with a range of coagulant doses to determine the efficacy of removing all forms of Hg from solution. Three industrial-grade coagulants were tested: ferric chloride, ferric sulfate, and polyaluminum chloride. Coagulation removed up to 85% of DOM from solution. In the absence of DOM, all three coagulants released IHg into solution, however in the presence of DOM the coagulants removed up to 97% of IHg and 80% of MeHg. Results suggest that the removal of Hg is mediated by DOM-coagulant interactions. There was a preferential association of IHg with the more aromatic, higher molecular weight fraction of DOM but no such relationship was found for MeHg. This study offers new fundamental insights regarding large-scale removal of Hg at environmentally relevant regarding large-scale removal of Hg at environmentally relevant concentrations.

Sub-microWatt threshold nanoisland lasers

PubMed Central

Jang, Hoon; Karnadi, Indra; Pramudita, Putu; Song, Jung-Hwan; Soo Kim, Ki; Lee, Yong-Hee

2015-01-01

Ultralow threshold nanolasers have been sought after as power efficient light sources in photonic integrated circuits. Here a single-cell nanobeam laser with a nanoisland quantum well is proposed and demonstrated. Continuous operation at 1.5 μm is achieved at room temperature with an ultralow lasing threshold of 210 nW in absorbed power. The size of the active medium is reduced to 0.7 × 0.25 × 0.02 μm3 by removing the absorptive quantum well region surrounding the central cavity. Relatively thick (420 nm) InP slabs are employed to improve the thermal and mechanical characteristics. The nanoisland-based structures will provide a new platform to engineer fundamental light–matter interactions by controlling the size and the location of the nanoemitters, allowing the realization of highly efficient nanophotonic devices. PMID:26391800

Enhancing Rain Garden Design to Promote Nitrate Removal

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, but in most cases they show much smaller removal rates of nitrate, likely due to the media’s high sand and low organic matter content that inhibit trate removal by denitrification. EPA’s pilot-scale research explores...

Designing Bioretention Systems to Improve Nitrogen Removal

EPA Science Inventory

Bioretention systems effectively remove many stormwater stressors, including oil/grease, heavy metals, phosphorus, and ammonium. However, reported nitrate removal performance is highly variable. Bioretention media is typically coarse-grained with low organic matter content, which...

[Characteristics of dry matter production and nitrogen accumulation in barley genotypes with high nitrogen utilization efficiency].

PubMed

Huang, Yi; Li, Ting-Xuan; Zhang, Xi-Zhou; Ji, Lin

2014-07-01

A pot experiment was conducted under low (125 mg x kg-1) and normal (250 mg x kg(-1)) nitrogen treatments. The nitrogen uptake and utilization efficiency of 22 barley cultivars were investigated, and the characteristics of dry matter production and nitrogen accumulation in barley were analyzed. The results showed that nitrogen uptake and utilization efficiency were different for barley under two nitrogen levels. The maximal values of grain yield, nitrogen utilization efficiency for grain and nitrogen harvest index were 2.87, 2.91 and 2.47 times as those of the lowest under the low nitrogen treatment. Grain yield and nitrogen utilization efficiency for grain and nitrogen harvest index of barley genotype with high nitrogen utilization efficiency were significantly greater than low nitrogen utilization efficiency, and the parameters of high nitrogen utilization efficiency genotype were 82.1%, 61.5% and 50.5% higher than low nitrogen utilization efficiency genotype under the low nitrogen treatment. Dry matter mass and nitrogen utilization of high nitrogen utilization efficiency was significantly higher than those of low nitrogen utilization efficiency. A peak of dry matter mass of high nitrogen utilization efficiency occurred during jointing to heading stage, while that of nitrogen accumulation appeared before jointing. Under the low nitrogen treatment, dry matter mass of DH61 and DH121+ was 34.4% and 38.3%, and nitrogen accumulation was 54. 8% and 58.0% higher than DH80, respectively. Dry matter mass and nitrogen accumulation seriously affected yield before jointing stage, and the contribution rates were 47.9% and 54.7% respectively under the low nitrogen treatment. The effect of dry matter and nitrogen accumulation on nitrogen utilization efficiency for grain was the largest during heading to mature stages, followed by sowing to jointing stages, with the contribution rate being 29.5% and 48.7%, 29.0% and 15.8%, respectively. In conclusion, barley genotype with high nitrogen utilization efficiency had a strong ability of dry matter production and nitrogen accumulation. It could synergistically improve yield and nitrogen utilization efficiency by enhancing the ability of nitrogen uptake and dry matter formation before jointing stage in barley.

Removal of pharmaceuticals from secondary effluents by an electro-peroxone process.

PubMed

Yao, Weikun; Wang, Xiaofeng; Yang, Hongwei; Yu, Gang; Deng, Shubo; Huang, Jun; Wang, Bin; Wang, Yujue

2016-01-01

This study compared the removal of pharmaceuticals from secondary effluents of wastewater treatment plants (WWTPs) by conventional ozonation and the electro-peroxone (E-peroxone) process, which involves electrochemically generating H2O2 in-situ from O2 in sparged O2 and O3 gas mixture (i.e., ozone generator effluent) during ozonation. Several pharmaceuticals with kO3 ranging from <0.1 to 6.8 × 10(5) M(-1) s(-1) were spiked into four secondary effluents collected from different WWTPs, and then treated by ozonation and the E-peroxone process. Results show that both processes can rapidly remove ozone reactive pharmaceuticals (diclofenac and gemfibrozil), while the E-peroxone process can considerably accelerate the removal of ozone-refractory pharmaceuticals (e.g., ibuprofen and clofibric acid) via indirect oxidation with OH generated from the reaction of sparged O3 with electro-generated H2O2. Compared with ozonation, the E-peroxone process enhanced the removal kinetics of ozone-refractory pharmaceuticals in the four secondary effluents by ∼40-170%, and the enhancement was more pronounced in secondary effluents that had relatively lower effluent organic matter (EfOM). Due to its higher efficiency for removing ozone-refractory pharmaceuticals, the E-peroxone process reduced the reaction time and electrical energy consumption required to remove ≥90% of all spiked pharmaceuticals from the secondary effluents as compared to ozonation. These results indicate that the E-peroxone process may provide a simple and effective way to improve existing ozonation system for pharmaceutical removal from secondary effluents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomass removal and its effect on productivity of an artificially regenerated forest stand in the Missouri ozarks

Treesearch

Flex Jr. Ponder

2007-01-01

Intensive harvesting, which removes a greater proportion of the forest biomass than conventional harvesting and the associated nutrients, may cause a decline in forest productivity. Planted seedling response to three biomass removal levels (1. removal of boles only=OM1, 2. all surface organic matter removed, forest floor not removed=OM2, and 3. removal of all surface...

Soil texture analysis revisited: Removal of organic matter matters more than ever

PubMed Central

Schjønning, Per; Watts, Christopher W.; Christensen, Bent T.; Munkholm, Lars J.

2017-01-01

Exact estimates of soil clay (<2 μm) and silt (2–20 μm) contents are crucial as these size fractions impact key soil functions, and as pedotransfer concepts based on clay and silt contents are becoming increasingly abundant. We examined the effect of removing soil organic matter (SOM) by H2O2 before soil dispersion and determination of clay and silt. Soil samples with gradients in SOM were retrieved from three long-term field experiments each with uniform soil mineralogy and texture. For soils with less than 2 g C 100 g-1 minerals, clay estimates were little affected by SOM. Above this threshold, underestimation of clay increased dramatically with increasing SOM content. Silt contents were systematically overestimated when SOM was not removed; no lower SOM threshold was found for silt, but the overestimation was more pronounced for finer textured soils. When exact estimates of soil particles <20 μm are needed, SOM should always be removed before soil dispersion. PMID:28542416

Soil texture analysis revisited: Removal of organic matter matters more than ever.

PubMed

Jensen, Johannes Lund; Schjønning, Per; Watts, Christopher W; Christensen, Bent T; Munkholm, Lars J

2017-01-01

Exact estimates of soil clay (<2 μm) and silt (2-20 μm) contents are crucial as these size fractions impact key soil functions, and as pedotransfer concepts based on clay and silt contents are becoming increasingly abundant. We examined the effect of removing soil organic matter (SOM) by H2O2 before soil dispersion and determination of clay and silt. Soil samples with gradients in SOM were retrieved from three long-term field experiments each with uniform soil mineralogy and texture. For soils with less than 2 g C 100 g-1 minerals, clay estimates were little affected by SOM. Above this threshold, underestimation of clay increased dramatically with increasing SOM content. Silt contents were systematically overestimated when SOM was not removed; no lower SOM threshold was found for silt, but the overestimation was more pronounced for finer textured soils. When exact estimates of soil particles <20 μm are needed, SOM should always be removed before soil dispersion.

Ten-year results from the North American long-term soil productivity study in the Western Gulf Coastal Plain

Treesearch

D. Andrew Scott; John Novosad; Gala Golddsmith

2007-01-01

Forest management operations have the greatest potential to reduce soil productivity through altered soil fertility and air/water balance, which are most affected by organic matter removal and compaction, respectively. The objectives of this study were to assess the early growth response to compaction, organic matter removal, and weed control on the ten locations of...

The North American long-term soil productivity experiment: findings from the first decade of research

Treesearch

Robert F. Powers; D. Andrew Scott; Felipe g. Sanchez; Richard A. Voldseth; Deborah Page-Dumroese; John D. Elioff; Douglas M. Stone

2005-01-01

First decade findings on the impacts of organic matter removal and soil compaction are reported for the 26 oldest installations in the nation-wide network of long-term soil productivity sites. Complete removal of surface organic matter led to declines in soil C concentration to 20 cm depth and to reduced nutrient availability. The effect is attributed mainly to the...

Effects of vegetation control and organic matter removal on soil water content in a young Douglas-fir plantation.

Treesearch

Warren D. Devine; Constance A. Harrington

2006-01-01

We evaluated the effects of vegetation control and organic matter (OM) removal on soil water content (SWC) in a Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation from age 3 through age 5. Treatments were presence versus absence of vegetation control through year 5 and bole only harvest of the previous stand versus total-tree harvest of...

Effect of soil compaction and organic matter removal on two earthworm populations and some soil properties in a hardwood forest

Treesearch

D. Jordan; V. C. Hubbard; F., Jr. Ponder; E. C. Berry

1999-01-01

Earthworms can alter the physical, chemical, and biological properties of a forest ecosystem. Any physical manipulation to the soil ecosystem may, in turn, affect the activities and ecology of earthworms. The effects of organic matter removal (logs and forest floor) and soil compaction on earthworm activities were measured in a central hardwood region (oakhickory)...

Growth response of dominant and co-dominant loblolly pines to organic matter removal, soil compaction, and competition control

Treesearch

Robert Eaton; William Smith; Kim Ludovici

2010-01-01

The Long Term Soil Productivity (LTSP) experiment is a U.S. Forest Service led effort to test the effects that organic matter removal, soil compaction, and competition control have forest soil productivity, as measured by tree growth. A replicated experiment was installed on the Croatan National Forest, NC, in winter 1991 and loblolly pine (Pinus taeda...

Decadal-scale changes in forest soil carbon and nitrogen storage are influenced by organic matter removal during timber harvest

Treesearch

Ryan M. Mushinski; Thomas W. Boutton; D. Andrew Scott

2017-01-01

This study investigates whether different intensities of organic matter removal associated with timber harvest influence decadal-scale storage of soil organic carbon (SOC) and total nitrogen (TN) in the top 1 m of mineral soil 18 years postharvest in a Pinus taeda L. forest in the Gulf Coastal Plain. We quantified forest harvest-related changes in...

Characterization of wastewater treatment by two microbial fuel cells in continuous flow operation.

PubMed

Kubota, Keiichi; Watanabe, Tomohide; Yamaguchi, Takashi; Syutsubo, Kazuaki

2016-01-01

A two serially connected single-chamber microbial fuel cell (MFC) was applied to the treatment of diluted molasses wastewater in a continuous operation mode. In addition, the effect of series and parallel connection between the anodes and the cathode on power generation was investigated experimentally. The two serially connected MFC process achieved 79.8% of chemical oxygen demand removal and 11.6% of Coulombic efficiency when the hydraulic retention time of the whole process was 26 h. The power densities were 0.54, 0.34 and 0.40 W m(-3) when electrodes were in individual connection, serial connection and parallel connection modes, respectively. A high open circuit voltage was obtained in the serial connection. Power density decreased at low organic loading rates (OLR) due to the shortage of organic matter. Power generation efficiency tended to decrease as a result of enhancement of methane fermentation at high OLRs. Therefore, high power density and efficiency can be achieved by using a suitable OLR range.

ELUCID. IV. Galaxy Quenching and its Relation to Halo Mass, Environment, and Assembly Bias

NASA Astrophysics Data System (ADS)

Wang, Huiyuan; Mo, H. J.; Chen, Sihan; Yang, Yang; Yang, Xiaohu; Wang, Enci; van den Bosch, Frank C.; Jing, Yipeng; Kang, Xi; Lin, Weipeng; Lim, S. H.; Huang, Shuiyao; Lu, Yi; Li, Shijie; Cui, Weiguang; Zhang, Youcai; Tweed, Dylan; Wei, Chengliang; Li, Guoliang; Shi, Feng

2018-01-01

We examine the quenched fraction of central and satellite galaxies as a function of galaxy stellar mass, halo mass, and the matter density of their large-scale environment. Matter densities are inferred from our ELUCID simulation, a constrained simulation of the local universe sampled by SDSS, while halo masses and central/satellite classification are taken from the galaxy group catalog of Yang et al. The quenched fraction for the total population increases systematically with the three quantities. We find that the “environmental quenching efficiency,” which quantifies the quenched fraction as a function of halo mass, is independent of stellar mass. And this independence is the origin of the stellar mass independence of density-based quenching efficiency found in previous studies. Considering centrals and satellites separately, we find that the two populations follow similar correlations of quenching efficiency with halo mass and stellar mass, suggesting that they have experienced similar quenching processes in their host halo. We demonstrate that satellite quenching alone cannot account for the environmental quenching efficiency of the total galaxy population, and that the difference between the two populations found previously arises mainly from the fact that centrals and satellites of the same stellar mass reside, on average, in halos of different mass. After removing these effects of halo mass and stellar mass, there remains a weak, but significant, residual dependence on environmental density, which is eliminated when halo assembly bias is taken into account. Our results therefore indicate that halo mass is the prime environmental parameter that regulates the quenching of both centrals and satellites.

[Optimization and comparison of nitrogen and phosphorus removal by different aeration modes in oxidation ditch].

PubMed

Guo, Chang-Zi; Peng, Dang-Cong; Cheng, Xue-Mei; Wang, Dan

2012-03-01

The oxidation ditch operation mode was simulated by sequencing batch reactor (SBR) system with alternate stirring and aeration. The nitrogen and phosphorus removal efficiencies were investigated in two different aeration modes: point aeration and step aeration. Experimental results show that oxygen is dissolved more efficiently in point aeration mode with a longer aerobic region in the same air supply capacity, but dissolved oxygen (DO) utilization efficiency for nitrogen and phosphorus removal is high in step aeration mode. Nitrification abilities of the two modes are equal with ammonia-nitrogen (NH4(+) -N) removal efficiency of 96.68% and 97.03%, respectively. Nitrifier activities are 4.65 and 4.66 mg x (g x h)(-1) respectively. When the ratio of anoxic zones and the aerobic zones were 1, the total nitrogen (TN) removal efficiency of point aeration mode in 2, 4 or 7 partitions was respectively 60.14%, 47.93% and 33.7%. The total phosphorus (TP) removal efficiency was respectively 28.96%, 23.75% and 24.31%. The less the partitions, the higher the nitrogen and phosphorus removal efficiencies, but it is in more favor of TN removal. As for step aeration mode with only one partitioning zone, the TN and TP removal efficiencies are respectively 64.21% and 49.09%, which is better than in point aeration mode, but more conducive to the improvement of TP removal efficiency. Under the condition of sufficient nitrification in step aeration mode, the nitrogen and phosphorus removal is better with the increase of anoxic zone. The removal efficiencies of TN and TP respectively rose to 73.94% and 54.18% when the ratio of anoxic zones and the aerobic zones was increased from 1 : 1 to 1. 8 : 1. As the proportion of anoxic zones was enlarged further, nitrification and operation stability were weakened so as to affect the nitrogen and phosphorus removal efficiencies.

Methods for removing contaminant matter from a porous material

DOEpatents

Fox, Robert V [Idaho Falls, ID; Avci, Recep [Bozeman, MT; Groenewold, Gary S [Idaho Falls, ID

2010-11-16

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

The activated iron system for phosphorus recovery in aqueous environments.

PubMed

Wan, Jun; Jiang, Xiaoqing; Zhang, Tian C; Hu, Jiong; Richter-Egger, Dana; Feng, Xiaonan; Zhou, Aijiao; Tao, Tao

2018-04-01

Finding a good sorbent for phosphorus (P) recovery from the aquatic environment is critical for preventing eutrophication and providing P resources. The activated iron system (mainly consisted of zero-valent iron (ZVI), Fe 3 O 4 and Fe 2+ ) has been reported to exhibit a favorable performance towards various contaminants in wastewater, but its effect on P recovery has not been studied systematically. In this study, we used Fe 2+ -nitrate pretreatment reaction to prepare the activated iron system and then applied it to P recovery. Results show that more than 99% P was removed from water in 60 min; co-existing anions (NO 3 - , Cl - and SO 4 2- ) and natural organic matter (NOM) had little effect on P removal. The P removal capacity of activated iron system is very high compared with currently reported sorbents. Externally-supplied Fe 2+ plays an important role on P removal in the system. Regeneration study shows that the activated iron system exhibited stable P recovery ability by using 0.1 M NaOH solution. Various methods were applied to characterize the ZVI and iron corrosion, and results conclude that sorption precipitation, and co-precipitation contribute to P removal. This method will be promising and have an application potential in the field for efficient and cost-effective recovery of P with cheap microscale zero valent iron. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Nitrogen Oxides on Elemental Mercury Removal by Nanosized Mineral Sulfide.

PubMed

Li, Hailong; Zhu, Lei; Wang, Jun; Li, Liqing; Lee, Po-Heng; Feng, Yong; Shih, Kaimin

2017-08-01

Because of its large surface area, nanosized zinc sulfide (Nano-ZnS) has been demonstrated in a previous study to be efficient for removal of elemental mercury (Hg 0 ) from coal combustion flue gas. The excellent mercury adsorption performance of Nano-ZnS was found to be insusceptible to water vapor, sulfur dioxide, and hydrogen chloride. However, nitrogen oxides (NO X ) apparently inhibited mercury removal by Nano-ZnS; this finding was unlike those of many studies on the promotional effect of NO X on Hg 0 removal by other sorbents. The negative effect of NO X on Hg 0 adsorption over Nano-ZnS was systematically investigated in this study. Two mechanisms were identified as primarily responsible for the inhibitive effect of NO X on Hg 0 adsorption over Nano-ZnS: (1) active sulfur sites on Nano-ZnS were oxidized to inactive sulfate by NO X ; and (2) the chemisorbed mercury, i.e., HgS, was reduced to Hg 0 by NO X . This new insight into the role of NO X in Hg 0 adsorption over Nano-ZnS can help to optimize operating conditions, maximize Hg 0 adsorption, and facilitate the application of Nano-ZnS as a superior alternative to activated carbon for Hg 0 removal using existing particulate matter control devices in power plants.

An alternative approach for nitrate and arsenic removal from wastewater via a nitrate-dependent ferrous oxidation process.

PubMed

Zhang, Meilin; Li, Yingfen; Long, Xinxian; Chong, Yunxiao; Yu, Guangwei; He, Zihao

2018-05-18

Owing to the high efficiency of converting nitrate to nitrogen gas with ferrous iron as the electron donor, the process of nitrate-dependent ferrous oxidation (NDFeO) has been considered suitable to treat wastewater that contains nitrate but lacks organic matter. Meanwhile, arsenic immobilization often has been found during the NDFeO reaction. Thus, it was strongly expected that nitrate and arsenic could be removed simultaneously in co-contaminated wastewater through the NDFeO process. However, in the current work, arsenic was not removed during the NDFeO process when the pH was high (above 8), though the nitrate reduction rate was over 90%. Meanwhile, the biosolid particles from the NDFeO process demonstrated strong adsorption ability for arsenic when the pH was below 6. Yet, the adsorption became weak when the pH was above 7. Fourier transform infrared (FTIR) spectroscopy analysis revealed that the main activated component for arsenic adsorption was iron oxide in these particles, which was easily crippled under high pH conditions. These results implied that co-removal of nitrate and arsenic in wastewater treatment using NDFeO was difficult to carry out under high pH conditions. Thus, a two-step approach in which nitrate was removed first by NDFeO followed by arsenic adsorption with NDFeO biosolids was more feasible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integrated horizontal-flow anaerobic and radial-flow aerobic reactors for the removal of organic matter and nitrogen from domestic sewage.

PubMed

Vieira, L G T; Fazolo, A; Zaiat, M; Foresti, E

2003-01-01

This paper presents the conception and discusses the results obtained from the operation of an integrated biological anaerobic/aerobic/anaerobic system composed of horizontal-flow anaerobic and radial-flow aerobic reactors for domestic sewage treatment. The performance of a horizontal-flow anaerobic immobilized biomass reactor, with five stages,followed by a radial-flow aerobic immobilized biomass reactor was evaluated along 22 weeks. After the 14th week, the last stage of the HAIB reactor was used as a denitrifying unit. Polyurethane foam cubic matrices with 1-cm sides were used as support for biomass immobilization in all the units. The influent domestic sewage presented mean chemical oxygen demand of 365 +/- 71 mg. 1(-1) and the temperature was 23 +/- 3degrees C. The integrated system achieved COD removal efficiency of 90% while the maximum ammonium removal efficiency was 97% in the aerobic post-treatment unit. The nitrification process was found to be better represented by first-order reactions in series model. The apparent first-order kinetic coefficient for nitrate formation was about 50 times higher than that estimated for the nitrite formation. The denitrification process was well represented by a Monod-type kinetic model. The maximum specific denitrifying rate and the half-saturation coefficient were 2.9 x 10(-4) mg NO(3)(-)-N mg(-1) VSS h(-1) and 19.4 mg NO(3)(-)-N 1(-1), respectively.

Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

PubMed

Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

2014-05-01

The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

Mass loss and nutrient concentrations of buried wood as a function of organic matter removal, soil compaction, and vegetation control in a regenerating oak-pine forest

Treesearch

Felix Ponder; John M. Kabrick; Mary Beth Adams; Deborah S. Page-Dumroese; Marty F. Jurgensen

2017-01-01

Mass loss and nutrient concentrations of northern red oak (Quercus rubra) and white oak (Q. alba) wood stakes were measured 30 months after their burial in the upper 10 cm of soil in a regenerating forest after harvesting and soil disturbance. Disturbance treatments were two levels of organic matter (OM) removal (only...

Negligible effects of severe organic matter removal and soil compaction on loblolly pine growth over 10 years

Treesearch

Felipe G. Sanchez; D. Andrew Scott; Kim H. Ludovici

2006-01-01

The long-term soil productivity (LTSP) study was initiated to examine the effect of soil porosity and organic matter (OM) levels on net primary productivity (NPP). The study design calls for three levels of OM removal (bole, whole tree and whole tree plus forest floor) and three levels of compaction (none, moderate and severe) being imposed on harvested sites prior to...

Microbial biomass and bacterial functional diversity in forest soils: effects of organic matter removal, compaction, and vegetation control

Treesearch

Qingchao Li; H. Lee Allen; Arthur G. Wollum

2004-01-01

The effects of organic matter removal, soil compaction, and vegetation control on soil microbial biomass carbon, nitrogen, C-to-N ratio, and functional diversity were examined in a 6-year loblolly pine plantation on a Coastal Plain site in eastern North Carolina, USA. This experimental plantation was established as part of the US Forest Service's Long Term Soil...

Aboveground biomass responses to organic matter removal, soil compaction, and competing vegetation control on 20-year mixed conifer plantations in California

Treesearch

Jianwei Zhang; Matt D. Busse; David H. Young; Gary O. Fiddler; Joseph W. Sherlock; Jeff D. TenPas

2017-01-01

We measured vegetation growth 5, 10, and 20 years following plantation establishment at 12 Long-term Soil Productivity installations in California’s Sierra Nevada and Southern Cascades. The combined effects of soil compaction (none, moderate, severe), organic matter removal (tree bole only, whole tree, whole tree plus forest floor), and competing vegetation...

Changes in soil physical and chemical properties following organic matter removal and compaction: 20-year response of the aspen Lake-States Long Term Soil Productivity installations

Treesearch

Robert A. Slesak; Brian J. Palik; Anthony W. D' Amato; Valerie J. Kurth

2017-01-01

Soil functions that control plant resource availability can be altered by management activities such as increased organic matter (OM) removal and soil compaction during forest harvesting. The Long Term Soil Productivity study was established to evaluate how these practices influence soil and site productivity using experimental treatments that span a range of forest...

Remediation of hydrophobic, persistent pollutants using a magnetic permanently confined micelle array (Mag-PCMA)

NASA Astrophysics Data System (ADS)

Clark, K. K.; Keller, A. A.

2009-12-01

Natural and anthropogenic factors have resulted in the deposition of hydrophobic organic contaminants (HOCs) like PAHs and PCBs in elevated levels in soils and sediments. Currently there are 150 Superfund sites in the United States with contaminated sediments. Dredging is the most common practice for restoring Superfund sites to their preexisting conditions; this requires the transport of large volumes of material off-site for additional storage or processing. Our lab has designed a nano-hybrid material that can be used on-site; it combines a magnetic nanoscale iron oxide core coated with a cationic surfactant and is encased in a mesoporous silica matrix, called magnetic permanently confined micelle arrays, (Mag-PCMAs). This sorbent has been designed to remove HOCs from such scenarios. Surfactants are important in the enhancement of transport from binding sites in nature, such as organic matter, onto sorbents and other recoverable materials. The sorbent’s magnetic core allows for rapid separation by applying a magnetic field. It has also been shown to be reusable and maintain a removal efficiency of 95% over five cycles of reuse. Preliminary sorption studies show that the sorbent is capable of removing up to 98% of hydrophobic compounds from aqueous media. Current sorption studies are being done to test the efficiency of removing PAHs and PCBs from sediments, soils, and suspended sediments. Physicochemical properties that will influence the desorption/sorption hysteresis are being characterized to determine which properties enhance desorption from the contaminated media onto the Mag-PCMAs. Relevant applications are diverse as this material has the potential to recover a variety of HOCs in both ex situ and in situ remediation scenarios. Magnetic Permanently Confined Micelle Arrays

Phthalate esters in the environment: A critical review of their occurrence, biodegradation, and removal during wastewater treatment processes.

PubMed

Gao, Da-Wen; Wen, Zhi-Dan

2016-01-15

Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.-10.4 ng/m(3), N.D.-31.7 μg/L, N.D.-316 μg/kg dry weight, and N.D.-200 μg/kg dry weight, N.D.-43.27 μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%-71% to 95%-97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Behavior, fate, and mass loading of short chain chlorinated paraffins in an advanced municipal sewage treatment plant.

PubMed

Zeng, Lixi; Li, Huijuan; Wang, Thanh; Gao, Yan; Xiao, Ke; Du, Yuguo; Wang, Yawei; Jiang, Guibin

2013-01-15

Sewage treatment plants (STP) are an important source of short chain chlorinated paraffins (SCCPs) to the ambient environment through discharge of effluent and application of sludge. In this work, a field study was conducted to determine the behavior and possible removal of SCCPs during the sewage treatment process in an advanced municipal STP in Beijing, China. SCCPs were detected in all sewage water and sludge samples, and 97% of the initial mass loading in raw sewage was found to be associated with suspended matter. The total concentrations in raw influent, tertiary effluent, and dewatered sludge were 184 ± 19 ng/L, 27 ± 6 ng/L, and 15.6 ± 1.4 μg/g dry weight (d.w.), respectively. The dissolved concentrations of total SCCPs (∑SCCPs) significantly decreased during mechanical, biological, and chemical treatments. SCCP homologue profiles in aqueous phase were distinctly different from those in solid phase. Along the treatment process, the relative abundance of shorter chain and lower chlorinated congeners gradually increased in sewage water, but no obvious variations of homologue profiles were found in sludge. Mass flow analysis indicated, the removal efficiency in aqueous phase for ∑SCCPs was 82.2%, and the congener-specific removal efficiencies were positively related to their solid-water partition coefficients (K(d)). Mass balance results indicated that 0.8% and 72.6% of the initial SCCP mass loading were ultimately found in the effluents and dewatered sludge, respectively, while the remaining 26.6% was lost mainly due to biodegradation/biotransformation. It was suggested that the activated sludge system including basic anaerobic-anoxic-aerobic processes played an effective role in removing SCCPs from the wastewater, while the sorption to sludge by hydrophobic interactions was an important fate of SCCPs during the sewage treatment.

Integration of ozonation and an anaerobic sequencing batch reactor (AnSBR) for the treatment of cherry stillage.

PubMed

Alvarez, Pedro M; Beltrán, Fernando J; Rodríguez, Eva M

2005-01-01

Cherry stillage is a high strength organic wastewater arising from the manufacture of alcoholic products by distillation of fermented cherries. It is made up of biorefractory polyphenols in addition to readily biodegradable organic matter. An anaerobic sequencing batch reactor (AnSBR) was used to treat cherry stillage at influent COD ranging from 5 to 50 g/L. Different cycle times were selected to test biomass organic loading rates (OLR(B)), from 0.3 to 1.2 g COD/g VSS.d. COD and TOC efficiency removals higher than 80% were achieved at influent COD up to 28.5 g/L but minimum OLR(B) tested. However, as a result of the temporary inhibition of acetogens and methanogens, volatile fatty acids (VFA) noticeably accumulated and methane production came to a transient standstill when operating at influent COD higher than 10 g/L. At these conditions, the AnSBR showed signs of instability and could not operate efficiently at OLR(B) higher than 0.3 g COD/g VSS.d. A feasible explanation for this inhibition is the presence of toxic polyphenols in cherry stillage. Thus, an ozonation step prior to the AnSBR was observed to be useful, since more than 75% of polyphenols could be removed by ozone. The integrated process was shown to be a suitable treatment technology as the following advantages compared to the single AnSBR treatment were observed: greater polyphenols and color removals, higher COD and TOC removal rates thus enabling the process to effectively operate at higher OLR, higher degree of biomethanation, and good stability with less risk of acidification.

Evaluation of Fenton and ozone-based advanced oxidation processes as mature landfill leachate pre-treatments.

PubMed

Cortez, Susana; Teixeira, Pilar; Oliveira, Rosário; Mota, Manuel

2011-03-01

Fenton treatment (Fe(2+)/H(2)O(2)) and different ozone-based Advanced Oxidation Processes (AOPs) (O(3), O(3)/OH(-) and O(3)/H(2)O(2)) were evaluated as pre-treatment of a mature landfill leachate, in order to improve the biodegradability of its recalcitrant organic matter for subsequent biological treatment. With a two-fold diluted leachate, at optimised experimental conditions (initial pH 3, H(2)O(2) to Fe(2+) molar ratio of 3, Fe(2+) dosage of 4 mmol L(-1), and reaction time of 40 min) Fenton treatment removed about 46% of chemical oxygen demand (COD) and increased the five-day biochemical oxygen demand (BOD(5)) to COD ratio (BOD(5)/COD) from 0.01 to 0.15. The highest removal efficiency and biodegradability was achieved by ozone at higher pH values, solely or combined with H(2)O(2). These results confirm the enhanced production of hydroxyl radical under such conditions. After the application for 60 min of ozone at 5.6 g O(3)h(-1), initial pH 7, and 400 mg L(-1) of hydrogen peroxide, COD removal efficiency was 72% and BOD(5)/COD increased from 0.01 to 0.24. An estimation of the operating costs of the AOPs processes investigated revealed that Fe(2+)/H(2)O(2) was the most economical system (8.2 € m(-3)g(-1) of COD removed) to treat the landfill leachate. This economic study, however, should be treated with caution since it does not consider the initial investment, prices at plant scale, maintenance and labour costs. Copyright © 2010 Elsevier Ltd. All rights reserved.

Removal of PCDD/Fs, PCP and mercury from sediments: Thermal oxidation versus pyrolysis.

PubMed

Chang, Moo-Been; Hsu, Yen-Chen; Chang, Shu-Hao

2018-05-07

A continuous pilot-scale system (CPS) equipped with effective air pollution control devices (APCDs) is used for remediating the sediments contaminated with PCDD/Fs, PCP and Hg simultaneously. The removal efficiencies of these three pollutants in sediments collected from seawater pond and river, respectively, are evaluated via thermal treatment processes. PAHs and CBz formed during thermal oxidation and pyrolysis are also analyzed for better understanding the behaviors of chlorinated organic compounds. Experimental results indicate that low-molecular-weight PAHs are closely related to the formation of CBz, PCDD/Fs, and CPs, while low chlorinated PCDD/Fs and CBz are predominant in flue gas with thermal oxidation. However, the PM concentration is higher in thermal oxidation than pyrolysis due to the higher air flow rate of thermal oxidation. It may bring more particles out of the furnace and have a greater potential to form PCDD/Fs within APCDs. Besides, the high air flow also dilutes the Hg vapor in flue gas and would require more energy to condense and collect Hg with the quench tower. Furthermore, for removal of total amount of PCDD/Fs, pyrolysis is better than thermal oxidation. Thus, pyrolysis is more suitable for remediating the contaminated sediment. The removal efficiencies of PCDD/Fs, PCP and Hg in sediments achieved with pyrolysis increase with increasing operating temperature and retention time in CPS. Overall, the residual concentrations of PCDD/Fs and PCP in river sediment are higher than that in seawater-pond sediment since significant formation of tar is observed due to higher organic matter content in river sediment. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR 63.9323 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.9323 Section 63.9323 Protection of Environment... determine the add-on control device emission destruction or removal efficiency? You must use the procedures... removal efficiency as part of the performance test required by § 63.9310. You must conduct three test runs...

40 CFR 63.9323 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.9323 Section 63.9323 Protection of Environment... determine the add-on control device emission destruction or removal efficiency? You must use the procedures... removal efficiency as part of the performance test required by § 63.9310. You must conduct three test runs...

40 CFR 63.4166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4166 Section 63.4166 Protection of Environment....4166 How do I determine the add-on control device emission destruction or removal efficiency? (a) For... device organic emissions destruction or removal efficiency, using Equation 2 of this section. ER23JY02...

40 CFR 63.3966 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.3966 Section 63.3966 Protection of Environment... or removal efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test...

40 CFR 63.4965 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4965 Section 63.4965 Protection of Environment....4965 How do I determine the add-on control device emission destruction or removal efficiency? You must... destruction or removal efficiency as part of the performance test required by § 63.4960. You must conduct...

40 CFR 63.3966 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.3966 Section 63.3966 Protection of Environment... or removal efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test...

The removal characteristics of natural organic matter in the recycling of drinking water treatment sludge: Role of solubilized organics.

PubMed

Zhou, Zhiwei; Yang, Yanling; Li, Xing; Ji, Siyang; Zhang, Hao; Wang, Shuai; Zeng, Qingping; Han, Xinghang

2016-01-01

To clarify the role of solubilized organics derived from drinking water treatment sludge (DWTS) in the elimination of natural organic matter (NOM) in the DWTS recycling process, a probe sonoreactor at a frequency of 25 kHz was used to solubilize the organics at varied specific energies. The coagulation behavior related to NOM removal in recycling the sonicated DWTS with and without solubilized organics was evaluated, and the effect on organic fractionations in coagulated water was determined. The study results could provide useful implications in designing DWTS recycling processes that avoid the enrichment of organic matter. Our results indicate that DWTS was disrupted through a low release of soluble chemical oxygen demand (SCOD) and proteins, which could deteriorate the coagulated water quality under the specific energy of 37.87-1212.1 kW h/kg TS. The optimal coagulation behavior for NOM removal was achieved by recycling the sonicated DWTS without solubilized organics at 151.5 kW h/kg TS specific energy. Recycling the sonicated DWTS could increase the enrichment potential of weakly hydrophobic acid, hydrophilic matter, and <3 kDa fractions; the enrichment risks could be reduced by discharging the solubilized organics. Fluorescent characteristic analysis indicated that when recycling the sonicated DWTS without solubilized organics, the removal of humic-like substances was limited, whereas removal of protein-like substances was enhanced, lowering the enrichment potential of protein-like substances. Copyright © 2015. Published by Elsevier B.V.

Performance of innovative textile biofilters for domestic wastewater treatment.

PubMed

Spychała, Marcin; Błazejewski, Ryszard; Nawrot, Tadeusz

2013-01-01

Two types of geotextile, TS 50 and TC/PP 300, were investigated as experimental filters. The raw wastewater, pre-treated in a septic tank, was intermittently dosed and filtered under hydrostatic pressure. At the beginning, the filter reactor comprised nine filters made of geotextiles (of three types: TS 10, TS 50 and TC/PP 300). At the end of the start-up period the TS 10 filters were removed due to their high outflow instability. After four months of working, the hydraulic capacities of the remaining filters were: 3.23 cm3/cm2/d for TS 50 and 4.14 cm3/cm2/d for TC/PP 300. The efficiencies of COD and BOD5 removal were similar for both types of geotextile (COD: 64%, BOD5: 80%). A small but statistically significant difference between ammonium nitrogen removal was observed (40% for TS 50 and 35% for TC/PP 300), most probably due to their different structure. Biological removal of P(tot) was relatively poor and similar for both geotextile types. The mean concentration of matter accumulated on the geotextiles was over one order of magnitude higher than conventional activated sludge concentrations. During the last weeks of the experiments the values of basic pollution indicators in the effluent were lower than the maximum permissible values (according to Polish law).

Combined effects of coagulation and adsorption on ultrafiltration membrane fouling control and subsequent disinfection in drinking water treatment.

PubMed

Xing, Jiajian; Liang, Heng; Cheng, Xiaoxiang; Yang, Haiyan; Xu, Daliang; Gan, Zhendong; Luo, Xinsheng; Zhu, Xuewu; Li, Guibai

2018-06-02

This study investigated the combined effects of coagulation and powdered activated carbon (PAC) adsorption on ultrafiltration (UF) membrane fouling control and subsequent disinfection efficiency through filtration performance, dissolved organic carbon (DOC) removal, fluorescence excitation-emission matrix (EEM) spectroscopy, and disinfectant curve. The fouling behavior of UF membrane was comprehensively analyzed especially in terms of pollutant removal and fouling reversibility to understand the mechanism of fouling accumulation and disinfectant dose reduction. Pre-coagulation with or without adsorption both achieved remarkable effect of fouling mitigation and disinfection dose reduction. The two pretreatments were effective in total fouling control and pre-coagulation combined with PAC adsorption even decreased hydraulically irreversible fouling notably. Besides, pre-coagulation decreased residual disinfectant decline due to the removal of hydrophobic components of natural organic matters (NOM). Pre-coagulation combined with adsorption had a synergistic effect on further disinfectant decline rate reduction and decreased total disinfectant consumption due to additional removal of hydrophilic NOM by PAC adsorption. The disinfectant demand was further reduced after membrane. These results show that membrane fouling and disinfectant dose can be reduced in UF coupled with pretreatment, which could lead to the avoidance of excessive operation cost disinfectant dose for drinking water supply.

Research of combined adsorption-coagulation process in treating petroleum refinery effluent.

PubMed

Wang, Bing; Shui, Yiyu; Ren, Hongyang; He, Min

2017-02-01

The petroleum refinery industry generates a significant amount of wastewater that contains a high level of organic matter, which calls for effective and costly treatments. In this research, the effectiveness of the petroleum refinery effluent (PRE) treatment with physicochemical process of combined adsorption and coagulation was evaluated. The effects of initial pH, hydraulic condition , and combined sequence of treatment process, different treating reagent types and dosages on the chemical oxygen demand (COD) removal were investigated. Additionally, the elimination efficiency of pollutant wastewater was monitored by gas chromatography-mass spectrometry (GC-MS), and Fourier transformed infrared (FT-IR) spectrophotometer was adopted to describe the structure of the wastewater. Wooden activated carbon was chosen as adsorbent at the dosage of 10 g/L as a primary treatment, and 1500 mg/L polymeric magnesium ferric sulfate was used in coagulation. Results showed that adsorption and subsequent coagulation displayed the best performance when initial pH was 9 at shear rates (G) of G1 = 65 s -1 and G2 = 20 s -1 , which reached maximal removal rate of COD and total organic carbon GC-MS testing result revealed that adsorption was effective in phenols and iso-alkanes removal, whereas coagulation was good at removing esters and n-alkanes.

Influence of softening sequencing on electrocoagulation treatment of produced water.

PubMed

Esmaeilirad, Nasim; Carlson, Ken; Omur Ozbek, Pinar

2015-01-01

Electrocoagulation has been used to remove solids and some metals from both water and wastewater sources for decades. Additionally, chemical softening is commonly employed in water treatment systems to remove hardness. This paper assesses the combination and sequence of softening and EC methods to treat hydraulic fracturing flowback and produced water from shale oil and gas operations. EC is one of the available technologies to treat produced water for reuse in frac fluids, eliminating not only the need to transport more water but also the costs of providing fresh water. In this paper, the influence of chemical softening on EC was studied. In the softening process, pH was raised to 9.5 and 10.2 before and after EC, respectively. Softening, when practiced before EC was more effective for removing turbidity with samples from wells older than one month (99% versus 88%). However, neither method was successful in treating samples collected from early flowback (1-day and 2-day samples), likely due to the high concentration of organic matter. For total organic carbon, hardness, Ba, Sr, and B removal, application of softening before EC appeared to be the most efficient approach, likely due to the formation of solids before the coagulation process. Copyright © 2014 Elsevier B.V. All rights reserved.

Ammonia removal via microbial fuel cell (MFC) dynamic reactor

NASA Astrophysics Data System (ADS)

Alabiad, I.; Ali, U. F. M.; Zakarya, I. A.; Ibrahim, N.; Radzi, R. W.; Zulkurnai, N. Z.; Azmi, N. H.

2017-06-01

Landfill leachate is generally known as high-strength wastewater that is difficult to handle and contains dissolved extracts and suspended matter. Microbial fuel cells (MFCs) were designed to treat landfill leachate while continuously producing power (voltage output). Three different anodes were tested in MFC reactors: carbon black, activated carbon, and zinc electrodes. Movements in the MFC reactor during treatment were also a key factor for testing. Results showed a difference in ammonia levels in the three anodes used. The study compared the efficiency of static and dynamic modes of MFC in removing ammonia. Continual leachate movement in the reactor could increase the rate of removal of the ammonia components. The setup provided a viable condition for maximum removal because the reactor movement caused the sludge to disintegrate, which allowed ammonia to separate easily from the parent leachate. Ammonia removal also resulted from the transfer of ammonium through the membrane or from ammonia loss. Constant exchange of ionic content benefited the MFC performance by increasing power production and decreasing internal electrode material resistance. This paper presents the results of the analyses of leachate treatment from the solid waste landfill located in Padang Siding Landfill, Perlis. The performance of ammonia removal was enhanced using different types of electrodes. In both modes, activated carbon performed better than black carbon and zinc. The respective percentages of ammonia removal for activated carbon of dynamic over static were 96.6%, 66.6%, and 92.8% for activated carbon, zinc, and black carbon. The results provide further information on the possibility of using MFCs in landfill leachate treatment systems.

Removal efficiency of water purifier and adsorbent for iodine, cesium, strontium, barium and zirconium in drinking water.

PubMed

Sato, Itaru; Kudo, Hiroaki; Tsuda, Shuji

2011-01-01

The severe incident of Fukushima Daiichi Nuclear Power Station has caused radioactive contamination of environment including drinking water. Radioactive iodine, cesium, strontium, barium and zirconium are hazardous fission products because of the high yield and/or relatively long half-life. In the present study, 4 pot-type water purifiers and several adsorbents were examined for the removal effects on these elements from drinking water. Iodide, iodate, cesium and barium were removed by all water purifiers with efficiencies about 85%, 40%, 75-90% and higher than 85%, respectively. These efficiencies lasted for 200 l, which is near the recommended limits for use of filter cartridges, without decay. Strontium was removed with initial efficiencies from 70% to 100%, but the efficiencies were slightly decreased by use. Zirconium was removed by two models, but hardly removed by the other models. Synthetic zeolite A4 efficiently removed cesium, strontium and barium, but had no effect on iodine and zirconium. Natural zeolite, mordenite, removed cesium with an efficiency as high as zeolite A4, but the removal efficiencies for strontium and barium were far less than those of zeolite A4. Activated carbon had little removal effects on these elements. In case of radioactive contamination of tap water, water purifiers may be available for convenient decontamination of drinking water in the home.

Effects of stratospheric ozone depletion, solar UV radiation, and climate change on biogeochemical cycling: interactions and feedbacks

DOE PAGES

Erickson III, David J.; Sulzberger, Barbara; Zepp, Richard G.; ...

2014-11-07

Climate change modulates the effects of solar UV radiation on biogeochemical cycles in terrestrial and aquatic ecosystems, particularly for carbon cycling, resulting in UV-mediated positive or negative feedbacks on climate. Possible positive feedbacks discussed in this assessment include: (i) enhanced UV-induced mineralisation of above ground litter due to aridification; (ii) enhanced UV-induced mineralisation of photoreactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting; (iii) reduced efficiency of the biological pump due to UV-induced bleaching of coloured dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solarmore » UV-B radiation. Mineralisation of organic matter results in the production and release of CO 2, whereas the biological pump is the main biological process for CO 2 removal by aquatic ecosystems. This research also assesses the interactive effects of solar UV radiation and climate change on the biogeochemical cycling of aerosols and trace gases other than CO 2, as well as of chemical and biological contaminants. Lastly,, interacting effects of solar UV radiation and climate change on biogeochemical cycles are particularly pronounced at terrestrial-aquatic interfaces.« less

40 CFR 63.3166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.3166 Section 63.3166 Protection of Environment... Limitations § 63.3166 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.3160. You must...

40 CFR 63.3166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.3166 Section 63.3166 Protection of Environment... Limitations § 63.3166 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.3160. You must...

40 CFR 63.4766 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4766 Section 63.4766 Protection of Environment... Option § 63.4766 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.4760. You must...

Virus removal efficiency of Cambodian ceramic pot water purifiers.

PubMed

Salsali, Hamidreza; McBean, Edward; Brunsting, Joseph

2011-06-01

Virus removal efficiency is described for three types of silver-impregnated, ceramic water filters (CWFs) produced in Cambodia. The tests were completed using freshly scrubbed filters and de-ionized (DI) water as an evaluation of the removal efficiency of the virus in isolation with no other interacting water quality variables. Removal efficiencies between 0.21 and 0.45 log are evidenced, which is significantly lower than results obtained in testing of similar filters by other investigators utilizing surface or rain water and a less frequent cleaning regime. Other experiments generally found virus removal efficiencies greater than 1.0 log. This difference may be because of the association of viruses with suspended solids, and subsequent removal of these solids during filtration. Variability in virus removal efficiencies between pots of the same manufacturer, and observed flow rates outside the manufacturer's specifications, suggest tighter quality control and consistency may be needed during production.

Application of Zero-Valent Iron Nanoparticles for the Removal of Aqueous Zinc Ions under Various Experimental Conditions

PubMed Central

Liang, Wen; Dai, Chaomeng; Zhou, Xuefei; Zhang, Yalei

2014-01-01

Application of zero-valent iron nanoparticles (nZVI) for Zn2+ removal and its mechanism were discussed. It demonstrated that the uptake of Zn2+ by nZVI was efficient. With the solids concentration of 1 g/L nZVI, more than 85% of Zn2+ could be removed within 2 h. The pH value and dissolved oxygen (DO) were the important factors of Zn2+ removal by nZVI. The DO enhanced the removal efficiency of Zn2+. Under the oxygen-contained condition, oxygen corrosion gave the nZVI surface a shell of iron (oxy)hydroxide, which could show high adsorption affinity. The removal efficiency of Zn2+ increased with the increasing of the pH. Acidic condition reduced the removal efficiency of Zn2+ by nZVI because the existing H+ inhibited the formation of iron (oxy)hydroxide. Adsorption and co-precipitation were the most likely mechanism of Zn2+ removal by nZVI. The FeOOH-shell could enhance the adsorption efficiency of nZVI. The removal efficiency and selectivity of nZVI particles for Zn2+ were higher than Cd2+. Furthermore, a continuous flow reactor for engineering application of nZVI was designed and exhibited high removal efficiency for Zn2+. PMID:24416439

Increase in volatilization of organic compounds using air sparging through addition in alcohol in a soil-water system.

PubMed

Chao, Huan-Ping; Hsieh, Lin-Han Chiang; Tran, Hai Nguyen

2018-02-15

This study developed a novel method to promote the remediation efficiency of air sparging. According to the enhanced-volatilization theory presented in this study, selected alcohols added to groundwater can highly enhance the volatilization amounts of organic compounds with high Henry's law constants. In this study, the target organic compounds consisted of n-hexane, n-heptane, benzene, toluene, 1,1,2-trichloroethane, and tetrachloroethene. n-pentanol, n-hexanol, and n-heptanol were used to examine the changes in the volatilization amounts of organic compounds in the given period. Two types of soils with high and low organic matter were applied to evaluate the transport of organic compounds in the soil-water system. The volatilization amounts of the organic compounds increased with increasing alcohol concentrations. The volatilization amounts of the test organic compounds exhibited a decreasing order: n-heptanol>n-hexanol>n-pentanol. When 10mg/L n-heptanol was added to the system, the maximum volatilization enhancement rate was 18-fold higher than that in distilled water. Samples of soil with high organic matter might reduce the volatilization amounts by a factor of 5-10. In the present study, the optimal removal efficiency for aromatic compounds was approximately 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigating the effect of hardness cations on coagulation: The aspect of neutralisation through Al(III)-dissolved organic matter (DOM) binding.

PubMed

Zhou, Yuxuan; Yan, Mingquan; Liu, Ruiping; Wang, Dongsheng; Qu, Jiuhui

2017-05-15

Hardness cations are ubiquitous and abundant in source water, while the effect of hardness on the performance of coagulation for dissolved organic matter (DOM) removal in water treatment remains unclear due to the limitation of methods that can characterise the subtle interactions between DOM, coagulant and hardness cations. This work quantified the competition between coagulant Al 3+ and hardness cations to bind onto DOM using absorbance spectroscopy acquired at different Al 3+ concentrations in the absence and presence of Ca 2+ or Mg 2+ . The results indicate that, in the presence of either Mg 2+ or Ca 2+ , an increasing depression of the binding of Al 3+ -DOM could be observed in the differential spectra of DOM with the increasing of Mg 2+ or Ca 2+ at a level of 10, 100 and 1000 μM, with the observation being more significant at higher pH from 6.5 to 8.5. The results of zeta potentials of DOM indicate that the competition of hardness cations results in the negative DOM being less efficiently neutralised by Al 3+ . This study demonstrates that the removal of DOM by coagulation would significantly deteriorate with the presence of hardness cations, which would compete with coagulant Al 3+ to neutralise the unsaturated sites in DOM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electricity generation from food wastes and microbial community structure in microbial fuel cells.

PubMed

Jia, Jianna; Tang, Yu; Liu, Bingfeng; Wu, Di; Ren, Nanqi; Xing, Defeng

2013-09-01

Microbial fuel cell (MFC) was studied as an alternate and a novel way to dispose food wastes (FWs) in a waste-to-energy form. Different organic loading rate obviously affected the performance of MFCs fed with FWs. The maximum power density of ~18 W/m(3) (~556 mW/m(2)) was obtained at COD of 3200±400 mg/L and the maximum coulombic efficiency (CE) was ~27.0% at COD of 4900±350 mg/L. The maximum removals of COD, total carbohydrate (TC) and total nitrogen (TN) were ~86.4%, ~95.9% and ~16.1%, respectively. Microbial community analysis using 454 pyrosequencing of 16S rRNA gene demonstrated the combination of the dominant genera of the exoelectrogenic Geobacter and fermentative Bacteroides effectively drove highly efficient and reliable MFC systems with functions of organic matters degradation and electricity generation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of organic matter removal and soil compaction on fifth-year mineral soil carbon and nitrogen contents for sites across the United States and Canada

Treesearch

Felipe G. Sanchez; Allan E. Tiarks; J. Marty Kranabetter; Deborah S. Page-Dumroese; Robert F. Powers; Paul T. Sanborn; William K. Chapman

2006-01-01

This study describes the main treatment effects of organic matter removal and compaction and a split-plot effect of competition control on mineral soil carbon (C) and nitrogen (N) pools. Treatment effects on soil C and N pools are discussed for 19 sites across five locations (British Columbia, Northern Rocky Mountains, Pacific Southwest, and Atlantic and Gulf coasts)...

Removal of residual particulate matter from filter media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almlie, Jay C.; Miller, Stanley J.

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Removal of residual particulate matter from filter media

DOEpatents

Almlie, Jay C; Miller, Stanley J

2014-11-11

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Free Fe(3+)/Fe(2+) improved the biomass resource recovery and organic matter removal in Rhodobacter sphaeroides purification of sewage.

PubMed

Liu, Rijia; Wu, Pan; Lang, Lang; Xu, Changru; Wang, Yanling

2016-01-01

The enhancement in biomass production and organic matter removal of Rhodobacter sphaeroides (R. sphaeroides) through iron ions in soybean protein wastewater treatment was investigated. Different dosages of ferric ions were introduced in the reactors under light-anaerobic conditions. Free ferric and ferrous ions in wastewater were formed and their concentrations were the optimal for the growth of R. sphaeroides when the total Fe dosage was 20 mg/L. At the optimal dosage, biomass production (4000 mg/L) and protease activity improved by 50% and 48% when compared to the controls, respectively. The organic matter and protein removal reached above 90% and hydraulic retention time was shortened from 96 to 72 h. A mechanism analysis indicated that iron ions can effectively improve the adenosine triphosphate production, which may furthermore encourage the synthesis of protease and the cellular material.

p-Nitrophenol removal by combination of powdered activated carbon adsorption and ultrafiltration - comparison of different operational modes.

PubMed

Ivancev-Tumbas, Ivana; Hobby, Ralph; Küchle, Benjamin; Panglisch, Stefan; Gimbel, Rolf

2008-09-01

Ultrafiltration is classified as a low-pressure membrane technology which effectively removes particulate matter and microorganisms and to a certain extent dissolved organic matter (15-25%) and colour. The technology has been optimized and is becoming competitive compared to conventional processes for larger scale plant capacities. In combination with activated carbon it is an effective barrier regarding the removal of synthetic organic chemicals. Growing interest in ultrafiltration raises the question of better usage of the adsorption capacity of powdered activated carbon (PAC) used in combination with this low-pressure membrane technique. This paper presents a pilot plant study of different PAC dosing procedures within a combined hybrid membrane IN/OUT process for removal of p-nitrophenol (PNP) from water (c(0)=1mg/L) under real case conditions (e.g. usage of the same module for the whole duration of the experiment, backwashing with permeate water, no separate saturation of the membrane with substance without presence of carbon). p-Nitrophenol was chosen as an appropriate test substance to assess the efficiency of different operation modes. Dead-end and cross-flow filtration were compared with respect to different PAC dosing procedures: continuous dosing into a continuously stirred tank reactor (CSTR) in front of the module and direct dosing into the pipe in front of the module (continuous, single-pulse and multi-pulse dosing). There was no advantage in cross-flow mode over dead-end referring to PNP concentration in the permeate. Relating to the carbon dosing procedure, the best results were obtained for continuous PAC addition. The option of dosing directly into the pipe has the advantage of no additional tank being necessary. In the case of single-pulse dosing, the formation of a carbon layer on the membrane surface was assumed and an LDF model applied for a simplified estimation of the "breakthrough behaviour" in the thus formed "PAC filter layer".

Development of super-clean diesel engine and combustor using nonthermal plasma hybrid aftertreatment

NASA Astrophysics Data System (ADS)

Okubo, Masaaki

2015-10-01

One of important and successful environmental applications of atmospheric-pressure corona discharge or plasma is electrostatic precipitator (ESP), which have been widely used for coal- or oil-fired boilers in electric power plants and particulate matter control emitted from industries such as glass melting furnace system, etc. In the ESPs, steady high voltage is usually applied to a pair of electrodes (at least, one of these has sharp edge). Unsteady pulsed high voltage is often applied for the collection of high-resistivity particulate matter (PM) to avoid reverse corona phenomena which reduce the collection efficiency of the ESPs. It was found that unsteady high voltage can treat hazardous gaseous components (NOx, SOx, hydrocarbon, and CO, etc.) in the exhaust gas, and researches were shifted from PM removal to hazardous gases aftertreatment with unsteady corona discharge induced plasmas. In the paper, recent results on diesel engine and industrial boiler emission controls are mainly reviewed among these our research topics.

Microbial communities change in an anaerobic digestion after application of microbial electrolysis cells.

PubMed

Lee, Beom; Park, Jun-Gyu; Shin, Won-Beom; Tian, Dong-Jie; Jun, Hang-Bae

2017-06-01

Microbial electrolysis cells (MECs) are being studied to improve the efficiency of anaerobic digesters and biogas production. In the present study, we investigated the effects of electrochemical reactions in AD-MEC (anaerobic digester combined with MECs) on changes in the microbial communities of bulk sludge through 454-pyrosequencing analysis, as well as the effect of these changes on anaerobic digestion. Methanobacterium beijingense and Methanobacterium petrolearium were the dominant archaeal species in AD, while Methanosarcina thermophila and Methanobacterium formicicum were dominant in AD-MEC at steady-state. There were no substantial differences in dominant bacterial species. Clostridia class was more abundant than Bacteroidia class in both reactors. Compared to AD, AD-MEC showed a 40% increase in overall bacterial population, increasing the removal of organic matters and the conversion of volatile fatty acids (VFAs). Thus, the MEC reaction more effectively converts organic matters to VFAs and activates microbial communities favorable for methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transformation and utilization of slowly biodegradable organic matters in biological sewage treatment of anaerobic anoxic oxic systems.

PubMed

Zhang, Q H; Jin, P K; Ngo, H H; Shi, X; Guo, W S; Yang, S J; Wang, X C; Wang, X; Dzakpasu, M; Yang, W N; Yang, L

2016-10-01

This study examined the distribution of carbon sources in two anaerobic anoxic oxic (AAO) sewage treatment plants in Xi'an and investigated the transformation characteristics and utilization potential of slowly biodegradable organic matters (SBOM). Results indicated under anaerobic and aerobic conditions, SBOM could be transformed at a rate of 65% in 8h into more readily biologically utilizable substrates such as volatile fatty acids (VFAs), polysaccharides and proteins. Additionally, non-biodegradable humus-type substances which are difficult to biodegrade and readily accumulate, were also generated. These products could be further hydrolyzed to aldehyde and ketone compounds and then transformed into substances with significant oxygen-containing functional groups and utilized subsequently. The molecular weights of proteinoid substances had a wide distribution and tended to decrease over time. Long hours of microbial reaction increased the proportion of micromolecular substances. This particular increase generated significant bioavailability, which can greatly improve the efficiency of nitrogen removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

How important are intertidal ecosystems for global biogeochemical cycles? Molecular and isotopic evidence for major outwelling of photo-bleached dissolved organic matter from mangroves.

NASA Astrophysics Data System (ADS)

Dittmar, T.; Cooper, W. T.; Koch, B. P.; Kattner, G.

2006-05-01

Organic matter, which is dissolved in low concentrations in the vast waters of the oceans, contains a total amount of carbon similar to atmospheric carbon dioxide. To understand global biogeochemical cycles it is crucial to quantify the sources of marine dissolved organic carbon (DOC). We investigated the impact of mangroves, the dominant intertidal vegetation of the tropics, on marine DOC inventories. Stable carbon- isotopes, ultrahigh-resolution mass spectrometry (FTICRMS), lignin-derived phenols and proton nuclear magnetic resonance spectroscopy showed that mangroves are the main source of terrigenous DOC on the shelf off Northern Brazil. Sunlight efficiently destroyed aromatic molecules during transport offshore, removing about one third of mangrove-derived DOC. The remainder was refractory and may thus be distributed over the oceans. On a global scale, we estimate that mangroves account for more than 10 percent of the terrestrially- derived, refractory DOC transported to the ocean, while they cover less than 0.1 percent of the continents' surface.

Effect of PAC dosage in a pilot-scale PAC-MBR treating micro-polluted surface water.

PubMed

Hu, Jingyi; Shang, Ran; Deng, Huiping; Heijman, Sebastiaan G J; Rietveld, Luuk C

2014-02-01

To address the water scarcity issue and advance the traditional drinking water treatment technique, a powdered activated carbon-amended membrane bioreactor (PAC-MBR) is proposed for micro-polluted surface water treatment. A pilot-scale study was carried out by initially dosing different amounts of PAC into the MBR. Comparative results showed that 2g/L performed the best among 0, 1, 2 and 3g/L PAC-MBR regarding organic matter and ammonia removal as well as membrane flux sustainability. 1g/L PAC-MBR exhibited a marginal improvement in pollutant removal compared to the non-PAC system. The accumulation of organic matter in the bulk mixture of 3g/L PAC-MBR led to poorer organic removal and severer membrane fouling. Molecular weight distribution of the bulk liquid in 2g/L PAC-MBR revealed the synergistic effects of PAC adsorption/biodegradation and membrane rejection on organic matter removal. Additionally, a lower amount of soluble extracellular polymer substances in the bulk can be secured in 21 days operation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Disinfection by-products and microbial contamination in the treatment of pool water with granular activated carbon.

PubMed

Uhl, W; Hartmann, C

2005-01-01

For swimming pools, it is generally agreed that free chlorine levels have to be maintained to guarantee adequate disinfection. Recommended free chlorine levels can vary between 0.3 and 0.6 mg/L in Germany and up to 3 mg/L in other countries. Bathers introduce considerable amounts of organic matter, mainly in the form of such as urine and sweat, into the pool water. As a consequence, disinfection byproducts (DBPs) are formed. Regulations in Germany recommend levels of combined chlorine of less than 0.2 mg/L and levels of trihalomethanes (THMs) of less than 20 microg/L. Haloacetic acids (HAAs), haloacetonitriles (HANs), chloropicrin and chloral hydrate are also detected in considerable amounts. However, these compounds are not regulated yet. Swimming pool staff and swimmers, especially athletes, are primarily exposed to these byproducts by inhalation and/or dermal uptake. In Germany, new regulations for swimming pool water treatment generally require the use of activated carbon. In this project, three different types of granular activated carbon (GAC) (one standard GAC, two catalytic GACs) are compared for their long time behaviour in pool water treatment. In a pilot plant operated with real swimming pool water, production and removal of disinfection byproducts (THMs, HAAs, AOXs), of biodegradable substances (AOC), of bacteria (Pseudomonas aeruginosa, Legionella, coliforms, HPC) as well as the removal of chlorine and chloramines are monitored as function of GAC bed depth. Combined chlorine penetrates deeper in the filter bed than free chlorine does. However, both, free and combined chlorine removal efficiencies decrease over the time of filter operation. The decreases of removal efficiencies are also observed for parameters such as dissolved organic carbon, spectral absorption coefficient, adsorbable organic carbon and most of the disinfection byproducts. However, THMs, especially chloroform are produced in the filter bed. The GAC beds were contaminated microbially, especially with P. aeruginosa. The contamination was not removable by backwashing with chlorine concentrations up to 2 mg/l free chlorine.

Removal of heavy metals from synthetic landfill leachate in lab-scale vertical flow constructed wetlands.

PubMed

A, Dan; Oka, Masao; Fujii, Yuta; Soda, Satoshi; Ishigaki, Tomonori; Machimura, Takashi; Ike, Michihiko

2017-04-15

Synthetic landfill leachate was treated using lab-scale vertical flow constructed wetlands (CWs) in sequencing batch modes to assess heavy metal removal efficiencies. The CWs filled with loamy soil and pumice stone were unplanted or planted with common reed (Phragmites australis) (Reed-CW) or common rush (Juncus effusus) (Rush-CW). Synthetic leachate contained acetate, propionate, humate, ammonium, and heavy metals. Common reed grew almost vigorously but common rush partly withered during the 8-month experiment. The CWs reduced the leachate volume effectively by evapotranspiration and removed easily degradable organic matter, color, and ammonium. Furthermore, the CWs demonstrated high removal amounts for heavy metals such as Zn, Cr, Ni, Cd, Fe, and Pb, but not Mn from leachate. The metal removal amounts in the CWs were low for high-strength leachate (influent concentration increased from one time to three times) or under short retention time (batch cycle shortened from 3days to 1day). The Rush-CW showed slightly lower removal amounts for Cr, Ni, Mn, and Cd, although the Reed-CW showed lower Mn removal amounts than the unplanted CW did. However, Cd, Cr, Pb, Ni, and Zn were highly accumulated in the upper soil layer in the planted CW by rhizofiltration with adsorption compared with unplanted CW, indicating that the emergent plants would be helpful for decreasing the dredging soil depth for the final removal of heavy metals. Although the emergent plants were minor sinks in comparison with soil, common rush had higher bioconcentration factors and translocation factors for heavy metals than common reed had. Copyright © 2017 Elsevier B.V. All rights reserved.

Statistical estimate of mercury removal efficiencies for air pollution control devices of municipal solid waste incinerators.

PubMed

Takahashi, Fumitake; Kida, Akiko; Shimaoka, Takayuki

2010-10-15

Although representative removal efficiencies of gaseous mercury for air pollution control devices (APCDs) are important to prepare more reliable atmospheric emission inventories of mercury, they have been still uncertain because they depend sensitively on many factors like the type of APCDs, gas temperature, and mercury speciation. In this study, representative removal efficiencies of gaseous mercury for several types of APCDs of municipal solid waste incineration (MSWI) were offered using a statistical method. 534 data of mercury removal efficiencies for APCDs used in MSWI were collected. APCDs were categorized as fixed-bed absorber (FA), wet scrubber (WS), electrostatic precipitator (ESP), and fabric filter (FF), and their hybrid systems. Data series of all APCD types had Gaussian log-normality. The average removal efficiency with a 95% confidence interval for each APCD was estimated. The FA, WS, and FF with carbon and/or dry sorbent injection systems had 75% to 82% average removal efficiencies. On the other hand, the ESP with/without dry sorbent injection had lower removal efficiencies of up to 22%. The type of dry sorbent injection in the FF system, dry or semi-dry, did not make more than 1% difference to the removal efficiency. The injection of activated carbon and carbon-containing fly ash in the FF system made less than 3% difference. Estimation errors of removal efficiency were especially high for the ESP. The national average of removal efficiency of APCDs in Japanese MSWI plants was estimated on the basis of incineration capacity. Owing to the replacement of old APCDs for dioxin control, the national average removal efficiency increased from 34.5% in 1991 to 92.5% in 2003. This resulted in an additional reduction of about 0.86Mg emission in 2003. Further study using the methodology in this study to other important emission sources like coal-fired power plants will contribute to better emission inventories. Copyright © 2010 Elsevier B.V. All rights reserved.

Granular activated carbon for removal of organic matter and turbidity from secondary wastewater.

PubMed

Hatt, J W; Germain, E; Judd, S J

2013-01-01

A range of commercial granular activated carbon (GAC) media have been assessed as pretreatment technologies for a downstream microfiltration (MF) process. Media were assessed on the basis of reduction in both organic matter and turbidity, since these are known to cause fouling in MF membranes. Isotherm adsorption analysis through jar testing with supplementary column trials revealed a wide variation between the different adsorbent materials with regard to organics removal and adsorption kinetics. Comparison with previous work using powdered activated carbon (PAC) revealed that for organic removal above 60% the use of GAC media incurs a significantly lower carbon usage rate than PAC. All GACs tested achieved a minimum of 80% turbidity removal. This combination of turbidity and organic removal suggests that GAC would be expected to provide a significant reduction in fouling of a downstream MF process with improved product water quality.

Nitrogen recovery from wastewater using gas-permeable membranes: Impact of inorganic carbon content and natural organic matter.

PubMed

Daguerre-Martini, S; Vanotti, M B; Rodriguez-Pastor, M; Rosal, A; Moral, R

2018-06-15

Gas-permeable membranes coupled with low-rate aeration is useful to recover ammonia (NH 4 + ) from livestock effluents. In this study, the role of inorganic carbon (bicarbonate, HCO 3 - ) to enhance the N recovery process was evaluated using synthetic effluents with various NH 4 + to HCO 3 - molar ratios of 0.5, 1.0, 1.5 and 2.0. The study also evaluated the effect of increased organic matter on the NH 4 + recovery using humic acids (3000-6000 mg L -1 ), and the N recovery from high-strength swine manure. The release of hydroxide from the HCO 3 - with aeration increased the wastewater pH and promoted gaseous ammonia formation and membrane uptake. At the same time, the recovery of gaseous ammonia (NH 3 ) through the membrane acidified the wastewater. Therefore, an abundant inorganic carbon supply in balance with the NH 4 + is needed for a successful operation of the technology. NH 4 + removal efficiencies >96% were obtained with NH 4 + to HCO 3 - ratios ≤1. However, higher molar ratios inhibited the N recovery process resulting in lower efficiencies (<65%). Fortunately, most swine manures contain ample supply of endogenous inorganic carbon and the process can be used to more economically recover the ammonia using the natural inorganic carbon instead of expensive alkali chemicals. In 4 days, the recovered NH 4 + from swine manure contained 48,000 mg L -1 . Finally, it was found the process was not inhibited by the increasing levels of organic matter in the wastewater evaluated. Published by Elsevier Ltd.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology

NASA Astrophysics Data System (ADS)

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium.

Comparative performance evaluation of full-scale anaerobic and aerobic wastewater treatment processes in Brazil.

PubMed

von Sperling, M; Oliveira, S C

2009-01-01

This article evaluates and compares the actual behavior of 166 full-scale anaerobic and aerobic wastewater treatment plants in operation in Brazil, providing information on the performance of the processes in terms of the quality of the generated effluent and the removal efficiency achieved. The observed results of effluent concentrations and removal efficiencies of the constituents BOD, COD, TSS (total suspended solids), TN (total nitrogen), TP (total phosphorus) and FC (faecal or thermotolerant coliforms) have been compared with the typical expected performance reported in the literature. The treatment technologies selected for study were: (a) predominantly anaerobic: (i) septic tank + anaerobic filter (ST + AF), (ii) UASB reactor without post-treatment (UASB) and (iii) UASB reactor followed by several post-treatment processes (UASB + POST); (b) predominantly aerobic: (iv) facultative pond (FP), (v) anaerobic pond followed by facultative pond (AP + FP) and (vi) activated sludge (AS). The results, confirmed by statistical tests, showed that, in general, the best performance was achieved by AS, but closely followed by UASB reactor, when operating with any kind of post-treatment. The effluent quality of the anaerobic processes ST + AF and UASB reactor without post-treatment was very similar to the one presented by facultative pond, a simpler aerobic process, regarding organic matter.

Treatment of sanitary landfill leachates in a lab-scale gradual concentric chamber (GCC) reactor.

PubMed

Mendoza, Lourdes; Verstraete, Willy; Carballa, Marta

2010-03-01

Sanitary landfill leachates are a major environmental problem in South American countries where sanitary landfills are still constructed and appropriate designs for the treatment of these leachates remain problematic. The performance of a lab-scale Gradual Concentric Chamber (GCC) reactor for leachates treatment is presented in this study. Two types of sanitary landfill residuals were evaluated, one directly collected from the garbage trucks (JGL), with high organic strength (84 g COD/l) and the second one, a 6-month-generated leachate (YL) collected from the lagoon of the sanitary landfill in Quito, Ecuador, with an organic strength of 66 g COD/l. Different operational parameters, such as organic loading rate (OLR), temperature, recycling and aeration, were tested. The GCC reactor was found to be a robust technology to treat these high-strength streams with organic matter removal efficiencies higher than 65%. The best performance of the reactors (COD removal efficiencies of 75-80%) was obtained at a Hydraulic Retention Time (HRT) of around 20 h and at 35 degrees C, with an applied OLR up to 70 and 100 g COD/l per day. Overall, the GCC reactor concept appears worth to be further developed for the treatment of leachates in low-income countries.

Application of acidogenic fixed-bed reactor prior to anaerobic membrane bioreactor for sustainable slaughterhouse wastewater treatment.

PubMed

Saddoud, Ahlem; Sayadi, Sami

2007-11-19

High rate anaerobic treatment systems such as anaerobic membrane bioreactors (AMBR) are less popular for slaughterhouse wastewater due to the presence of high fat oil and suspended matters in the effluent. This affects the performance and efficiency of the treatment system. In this work, AMBR has been tried for slaughterhouse wastewater treatment. After the start up period, the reactor was operated with an average organic loading rate (OLR) of 4.37 kg TCODm(-3)d(-1) with gradual increase to an average of 13.27 kg TCODm(-3)d(-1). At stable conditions, the treatment efficiency was high with an average COD and BOD(5) reduction of 93.7 and 93.96%, respectively. However, a reduction in the AMBR performance was shown with the increase of the OLR to 16.32 kg TCODm(-3)d(-1). The removal efficiencies of SCOD and BOD(5) were drastically decreased to below 53.6 and 73.3%, respectively. The decrease of the AMBR performance was due to the accumulation of VFAs. Thus, a new integrated system composed of a FBR for the acidogenesis step followed by the AMBR for methanogenesis step was developed. At high ORL, the integrated system improved the performance of the anaerobic digestion and it successfully overcame the VFA accumulation problem in the AMBR. The anaerobic treatment led to a total removal of all tested pathogens. Thus, the microbiological quality of treated wastewater fits largely with WHO guidelines.

In-situ regeneration of saturated granular activated carbon by an iron oxide nanocatalyst.

PubMed

Chiu, Chao-An; Hristovski, Kiril; Huling, Scott; Westerhoff, Paul

2013-03-15

Granular activated carbon (GAC) can remove trace organic pollutants and natural organic matter (NOM) from industrial and municipal waters. This paper evaluates an iron nanocatalyst approach, based on Fenton-like oxidation reactions, to regenerate spent GAC within a packed bed configuration after saturation by organic compounds. Specifically, we focus on regenerating GAC packed beds equilibrated with varying influent concentrations of phenol, a model organic compound. Iron nanocatalysts were synthesized using ferric chloride, a chemical already used as a coagulant at municipal WTPs, and reacted with hydrogen peroxide (H(2)O(2)) for the purpose of in-situ regeneration. Up to 95% of phenol adsorption capacity was regenerated for GAC equilibrated with 1000 mg/L of phenol. Using this technique, at least four adsorption-regeneration cycles can be performed sequentially for the same batch of GAC with fresh iron nanocatalysts while achieving a regeneration efficiency of 90 ± 5% between each loading. Moreover, the iron nanocatalyst can be recovered and reused multiple times. Lower initial adsorbate concentrations (10-500 mg/L) resulted in a slightly lower saturated adsorbent-phase concentration of phenol and lower regeneration efficiencies (72 ± 5%). Additionally, this catalytic in-situ regeneration was applied to GAC saturated by NOM. A slightly lower regeneration efficiency (60%) was observed for the Suwannee River NOM adsorption capacity of GAC. The next step is validation in a pilot-scale test that applies this regeneration technique to a GAC adsorber employed in NOM removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Frontal Lobe Decortication (Frontal Lobectomy with Ventricular Preservation) in Epilepsy-Part 1: Anatomic Landmarks and Surgical Technique.

PubMed

Wen, Hung Tzu; Da Róz, Leila Maria; Rhoton, Albert L; Castro, Luiz Henrique Martins; Teixeira, Manoel Jacobsen

2017-02-01

An extensive frontal resection is a frequently performed neurosurgical procedure, especially for treating brain tumor and refractory epilepsy. However, there is a paucity of reports available regarding its surgical anatomy and technique. We sought to present the anatomic landmarks and surgical technique of the frontal lobe decortication (FLD) in epilepsy. The goals were to maximize the gray matter removal, spare primary and supplementary motor areas, and preserve the frontal horn. The anatomic study was based on dissections performed in 15 formalin-fixed adult cadaveric heads. The clinical experience with 15 patients is summarized. FLD consists of 5 steps: 1) coagulation and section of arterial branches of lateral surface; 2) paramedian subpial resection 3 cm ahead of the precentral sulcus to reach the genu of corpus callosum; 3) resection of gray matter of lateral surface, preserving the frontal horn; 4) removal of gray matter of basal surface preserving olfactory tract; 5) removal of gray matter of the medial surface under the rostrum of corpus callosum. The frontal horn was preserved in all 15 patients; 12 patients (80%) had no complications; 2 patients presented temporary hemiparesis; and 1 Rasmussen syndrome patient developed postoperative fever. The best seizure control was in cases with focal magnetic resonance imaging abnormalities limited to the frontal lobe. FLD is an anatomy-based surgical technique for extensive frontal lobe resection. It presents reliable anatomic landmarks, selective gray matter removal, preservation of frontal horn, and low complication rate in our series. It can be an alternative option to the classical frontal lobectomy. Copyright © 2016 Elsevier Inc. All rights reserved.

Spin-analyzed SANS for soft matter applications

NASA Astrophysics Data System (ADS)

Chen, W. C.; Barker, J. G.; Jones, R.; Krycka, K. L.; Watson, S. M.; Gagnon, C.; Perevozchivoka, T.; Butler, P.; Gentile, T. R.

2017-06-01

The small angle neutron scattering (SANS) of nearly Q-independent nuclear spin-incoherent scattering from hydrogen present in most soft matter and biology samples may raise an issue in structure determination in certain soft matter applications. This is true at high wave vector transfer Q where coherent scattering is much weaker than the nearly Q-independent spin-incoherent scattering background. Polarization analysis is capable of separating coherent scattering from spin-incoherent scattering, hence potentially removing the nearly Q-independent background. Here we demonstrate SANS polarization analysis in conjunction with the time-of-flight technique for separation of coherent and nuclear spin-incoherent scattering for a sample of silver behenate back-filled with light water. We describe a complete procedure for SANS polarization analysis for separating coherent from incoherent scattering for soft matter samples that show inelastic scattering. Polarization efficiency correction and subsequent separation of the coherent and incoherent scattering have been done with and without a time-of-flight technique for direct comparisons. In addition, we have accounted for the effect of multiple scattering from light water to determine the contribution of nuclear spin-incoherent scattering in both the spin flip channel and non-spin flip channel when performing SANS polarization analysis. We discuss the possible gain in the signal-to-noise ratio for the measured coherent scattering signal using polarization analysis with the time-of-flight technique compared with routine unpolarized SANS measurements.

Stability studies for titanium dioxide nanoparticles upon adsorption of Suwannee River humic and fulvic acids and natural organic matter.

PubMed

Erhayem, Mohamed; Sohn, Mary

2014-01-15

In many studies humic acid, fulvic acid, or natural organic matter is used interchangeably to model the effect of naturally derived organic matter on geochemical processes in the environment. In this study, the term NOOM (naturally occurring organic matter) is used to include both humic and fulvic acids as well as natural organic matter and compares the effect of NOOM type on NOOM removal onto nano-TiO2. In general, regardless of variations in solution chemistry, the order of the percentage of removal of NOOM onto nano-TiO2 was humic acid>natural organic matter>fulvic acid. The order of adsorption constant values of NOOM onto nano-TiO2 was also found to be humic acid>natural organic matter>fulvic acid under all conditions studied. The extent of NOOM removal by nano-TiO2 was enhanced in the presence of the divalent ions, magnesium and calcium, at pH7.8 when compared to the presence of the monovalent ions, sodium and potassium. Also, lower NOOM removal by nano-TiO2 in the presence of sodium salts of dihydrogen phosphate, bicarbonate and nitrate relative to chloride was observed and was likely due to the competition between polyatomic anions and NOOM adsorption onto the surface of nano-TiO2 indicating an anionic effect. Low concentrations of NOOM (10-20 mg L(-1)) destabilized nano-TiO2 in solution, however, the stability of nano-TiO2 increased as the amount of NOOM adsorbed onto nano-TiO2 increased at higher dissolved NOOM concentrations and significant stabilization was seen at 25 mg L(-1) NOOM. Thus, the three fractions of NOOM, humic and fulvic acids and natural organic matter and their concentrations were found to affect nano-TiO2 stability to different degrees although pH dependent trends in cation and anion effects had similar patterns. While the effects of adsorption of these three commonly used types of NOOM onto nanoparticles are similar, there are important differences that can be related to structural differences. © 2013.

Adsorption behavior and mechanism of Cd(II) on loess soil from China.

PubMed

Wang, Yan; Tang, Xiaowu; Chen, Yunmin; Zhan, Liangtong; Li, Zhenze; Tang, Qiang

2009-12-15

Cadmium is a toxic heavy metal that has caused serious public health problems. It is necessary to find a cost effective method to deal with wastewater containing Cd(II). Loess soils in China have proven to be a potential adsorbent for Cd(II) removal from wastewater. The adsorption capacity of loess towards Cd(II) has been determined to be about 9.37 mg g(-1). Slurry concentration, initial solution pH, reaction time and temperature have also been found to significantly influence the efficiency of Cd(II) removal. The adsorption isotherms and kinetics of loess soil from China can be best-fit with the Langmuir model and pseudo-second order kinetics model, respectively. The thermodynamic analysis revealed that the adsorption process was spontaneous, endothermic and the system disorder increased with duration. The natural organic matter in loess soil is mainly responsible for Cd(II) removal at pH < 4.2, while clay minerals contribute to a further gradual adsorption process. Chemical precipitation dominates the adsorption stage at pH > 8.97. Further studies using X-ray diffraction, Fourier transform infrared spectra of Cd(II) laden loess soil and Cd(II) species distribution have confirmed the adsorption mechanism.

Photo-Electrochemical Treatment of Reactive Dyes in Wastewater and Reuse of the Effluent: Method Optimization

PubMed Central

Sala, Mireia; López-Grimau, Víctor; Gutiérrez-Bouzán, Carmen

2014-01-01

In this work, the efficiency of a photo-electrochemical method to remove color in textile dyeing effluents is discussed. The decolorization of a synthetic effluent containing a bi-functional reactive dye was carried out by applying an electrochemical treatment at different intensities (2 A, 5 A and 10 A), followed by ultraviolet irradiation. The combination of both treatments was optimized. The final percentage of effluent decolorization, the reduction of halogenated organic volatile compound and the total organic carbon removal were the determinant factors in the selection of the best treatment conditions. The optimized method was applied to the treatment of nine simulated dyeing effluents prepared with different reactive dyes in order to compare the behavior of mono, bi, and tri-reactive dyes. Finally, the nine treated effluents were reused in new dyeing processes and the color differences (DECMC (2:1)) with respect to a reference were evaluated. The influence of the effluent organic matter removal on the color differences was also studied. The reuse of the treated effluents provides satisfactory dyeing results, and an important reduction in water consumption and salt discharge is achieved. PMID:28788251

Biotic conversion of sulphate to sulphide and abiotic conversion of sulphide to sulphur in a microbial fuel cell using cobalt oxide octahedrons as cathode catalyst.

PubMed

Chatterjee, Pritha; Ghangrekar, M M; Rao, Surampalli; Kumar, Senthil

2017-05-01

Varying chemical oxygen demand (COD) and sulphate concentrations in substrate were used to determine reaction kinetics and mass balance of organic matter and sulphate transformation in a microbial fuel cell (MFC). MFC with anodic chamber volume of 1 L, fed with wastewater having COD of 500 mg/L and sulphate of 200 mg/L, could harvest power of 54.4 mW/m 2 , at a Coulombic efficiency of 14%, with respective COD and sulphate removals of 90 and 95%. Sulphide concentration, even up to 1500 mg/L, did not inhibit anodic biochemical reactions, due to instantaneous abiotic oxidation to sulphur, at high inlet sulphate. Experiments on abiotic oxidation of sulphide to sulphur revealed maximum oxidation taking place at an anodic potential of -200 mV. More than 99% sulphate removal could be achieved in a MFC with inlet COD/sulphate of 0.75, giving around 1.33 kg/m 3  day COD removal. Bioelectrochemical conversion of sulphate facilitating sulphur recovery in a MFC makes it an interesting pollution abatement technique.

Water quality improvement of treated wastewater by intermittent soil percolation.

PubMed

Castillo, G; Mena, M P; Dibarrart, F; Honeyman, G

2001-01-01

Our research aimed to evaluate intermittent soil infiltration of treated sewage for reuse in the north of Chile. Aerated lagoon effluent was infiltrated in columns packed with native soils (sandy-lime, lime-gravel and limey-sand). Columns were operated for more than a year under different cycles of filling and drying, depths and load pressures depending on soil characteristics. The efficiency of the system was determined through influent-effluent microbiological indicators level (faecal coliforms, E. coli, Salmonella spp, MS2 phage, and protozoan cysts), physicochemical characterisation (TOC, COD, BOD, nitrogen), and hydraulic flow measurement. Results showed: (a) high reduction of enteric bacteria (5-7 log10), some inactivation of phage (2-4 log10) and complete removal of intestinal cyst; (b) stable removal of organic matter (80-90% reduction of TOC, COD, BOD); and (c) partial ammonia reduction through adsorption and nitrification with denitrification mainly occurring in sandy soil. Preliminary data from pilot plant working in the field showed better results that those obtained in the laboratory especially removal of microbiological indicators. Microbiological quality of effluent met Class A regulations for agricultural reuse (WHO, 1989) and the system looks like an attractive alternative to cope with water shortage in the region.

Polishing of POME by Chlorella sp. in suspended and immobilized system

NASA Astrophysics Data System (ADS)

Lahin, F. A.; Sarbatly, R.; Suali, E.

2016-06-01

The effect of using suspended and immobilized growth of Chlorella sp. to treat POME was studied. Cotton and nylon ropes were used as the immobilization material in a rotating microalgae biofilm reactor. The result showed that POME treated in suspended growth system was able to remove 81.9% and 55.5% of the total nitrogen (TN) and total phosphorus (TP) respectively. Whereas the immobilized system showed lower removal of 77.22% and 53.02% for TN and TP. Lower performance of immobilized microalgae is due to the limited light penetration and supply of CO2 inside the immobilization materials. The rotating microalgae biofilm reactor was able to reduce the biochemical oxygen demand (BOD) to 90 mg/L and chemical oxygen demand (COD) to 720 mg/L. Higher BOD and COD reading were obtained in suspended growth due to the presence of small number of microalgae cell in the samples. This study shows that suspended growth system is able to remove higher percentages of nitrogen and phosphorus. However, an efficient separation method such as membrane filtration is required to harvest the cultivated microalgae cell to avoid organic matter release into water bodies.

Effect of algal flocculation on dissolved organic matters using cationic starch modified soils.

PubMed

Shi, Wenqing; Bi, Lei; Pan, Gang

2016-07-01

Modified soils (MSs) are being increasingly used as geo-engineering materials for the sedimentation removal of cyanobacterial blooms. Cationic starch (CS) has been tested as an effective soil modifier, but little is known about its potential impacts on the treated water. This study investigated dissolved organic matters in the bloom water after algal removal using cationic starch modified soils (CS-MSs). Results showed that the dissolved organic carbon (DOC) could be decreased by CS-MS flocculation and the use of higher charge density CS yielded a greater DOC reduction. When CS with the charge density of 0.052, 0.102 and 0.293meq/g were used, DOC was decreased from 3.4 to 3.0, 2.3 and 1.7mg/L, respectively. The excitation-emission matrix fluorescence spectroscopy and UV254 analysis indicated that CS-MS exhibits an ability to remove some soluble organics, which contributed to the DOC reduction. However, the use of low charge density CS posed a potential risk of DOC increase due to the high CS loading for effective algal removal. When CS with the charge density of 0.044meq/g was used, DOC was increased from 3.4 to 3.9mg/L. This study suggested, when CS-MS is used for cyanobacterial bloom removal, the content of dissolved organic matters in the treated water can be controlled by optimizing the charge density of CS. For the settled organic matters, other measures (e.g., capping treatments using oxygen loaded materials) should be jointly applied after algal flocculation. Copyright © 2016. Published by Elsevier B.V.

Assessment of coagulation pretreatment of leachate by response surface methodology.

PubMed

Lessoued, Ridha; Souahi, Fatiha; Castrillon Pelaez, Leonor

2017-11-01

Coagulation-flocculation is a relatively simple technique that can be used successfully for the treatment of old leachate by poly-aluminum chloride (PAC). The main objectives of this study are to design the experiments, build models and optimize the operating parameters, dosage m and pH, using the central composite design and response surface method. Developed for chemical organic matter (COD) and turbidity responses, the quadratic polynomial model is suitable for prediction within the range of simulated variables as it showed that the optimum conditions were m of 5.55 g/L at pH 7.05, with a determination coefficient R² at 99.33%, 99.92% and adjusted R² at 98.85% and 99.86% for both COD and turbidity. We confirm that the initial pH and PAC dosage have significant effects on COD and turbidity removal. The experimental data and model predictions agreed well and the removal efficiency of COD, turbidity, Fe, Pb and Cu reached respectively 61%, 96.4%, 97.1%, 99% and 100%.

Adsorption behavior comparison of trivalent and hexavalent chromium on biochar derived from municipal sludge.

PubMed

Chen, Tan; Zhou, Zeyu; Xu, Sai; Wang, Hongtao; Lu, Wenjing

2015-08-01

In this work, static equilibrium experiments were conducted to distinguish the adsorption performance between the two valence states of chromium on biochar derived from municipal sludge. The removal capacity of Cr(VI) is lower than 7mg/g at the initial chromium concentration range of 50-200mg/L, whereas that of Cr(III) higher than 20mg/g. It indicates that Cr(III) is much easier to be stabilized than Cr(VI). No significant changes in the biochar surface functional groups are observed before and after the adsorption equilibrium, demonstrating the poor contribution of organic matter in chromium adsorption. The main mechanism of heavy metal adsorption by biochar involves (1) surface precipitation through pH increase caused by biochar buffer ability, and (2) exchange between cations in solution (Cd(2+)) and in biochar matrix (e.g. Ca(2+) and Mg(2+)). The reduction of Cr(VI) to Cr(III) is necessary to improve removal efficiency of chromium. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hybrid process of BAC and sMBR for treating polluted raw water.

PubMed

Tian, Jia-yu; Chen, Zhong-lin; Yang, Yan-ling; Liang, Heng; Nan, Jun; Wang, Zhao-zhi; Li, Gui-bai

2009-12-01

The hybrid process of biological activated carbon (BAC) and submerged membrane bioreactor (sMBR) was evaluated for the drinking water treatment from polluted raw water, with the respective hydraulic retention time of 0.5 h. The results confirmed the synergetic effects between the BAC and the subsequent sMBR. A moderate amount of ammonium (54.5%) was decreased in the BAC; while the total removal efficiency was increased to 89.8% after the further treatment by the sMBR. In the hybrid process, adsorption of granular activated carbon (in BAC), two stages of biodegradation (in BAC and sMBR), and separation by the membrane (in sMBR) jointly contributed to the removal of organic matter. As a result, the hybrid process managed to eliminate influent DOC, UV(254), COD(Mn), TOC, BDOC and AOC by 26.3%, 29.9%, 22.8%, 27.8%, 57.2% and 49.3%, respectively. Due to the pre-treatment effect of BAC, the membrane fouling in the downstream sMBR was substantially mitigated.

Anaerobic digestion of thin stillage for energy recovery and water reuse in corn-ethanol plants.

PubMed

Alkan-Ozkaynak, A; Karthikeyan, K G

2011-11-01

Recycling of anaerobically-digested thin stillage within a corn-ethanol plant may result in the accumulation of nutrients of environmental concern in animal feed coproducts and inhibitory organic materials in the fermentation tank. Our focus is on anaerobic digestion of treated (centrifugation and lime addition) thin stillage. Suitability of digestate from anaerobic treatment for reuse as process water was also investigated. Experiments conducted at various inoculum-to-substrate ratios (ISRs) revealed that alkalinity is a critical parameter limiting digestibility of thin stillage. An ISR level of 2 appeared optimal based on high biogas production level (763 mL biogas/g volatile solids added) and organic matter removal (80.6% COD removal). The digester supernatant at this ISR level was found to contain both organic and inorganic constituents at levels that would cause no inhibition to ethanol fermentation. Anaerobic digestion of treated-thin stillage can be expected to improve the water and energy efficiencies of dry grind corn-ethanol plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Membrane technology for sustainable treated wastewater reuse: agricultural, environmental and hydrological considerations.

PubMed

Oron, Gideon; Gillerman, Leonid; Bick, Amos; Manor, Yossi; Buriakovsky, Nisan; Hagin, Joseph

2008-01-01

Field experiments were conducted in agricultural fields in which secondary wastewater of the City of Arad (Israel) is reused for irrigation. For sustainable agricultural production and safe groundwater recharge the secondary effluent is further polished by a combined two-stage membrane pilot system. The pilot membrane system consists of two main in row stages: Ultrafiltration (UF) and Reverse Osmosis (RO). The UF stage is efficient in the removal of the pathogens and suspended organic matter while the successive RO stage provides safe removal of the dissolved solids (salinity). Effluents of various qualities were applied for agricultural irrigation along with continuous monitoring of the membrane system performance. Best agricultural yields were obtained when applying effluent having minimal content of dissolved solids (after the RO stage) as compared with secondary effluent without any further treatment and extended storage. In regions with shallow groundwater reduced soil salinity in the upper productive layers, maintained by extra membrane treatment, will guarantee minimal dissolved solids migration to the aquifers and minimize salinisation processes. (c) IWA Publishing 2008.

Advanced treatment of sodium dithionite wastewater using the combination of coagulation, catalytic ozonation, and SBR.

PubMed

Zou, Xiao-Ling

2017-10-01

A combined process of coagulation-catalytic ozonation-anaerobic sequencing batch reactor (ASBR)-SBR was developed at lab scale for treating a real sodium dithionite wastewater with an initial chemical oxygen demand (COD) of 21,760-22,450 mg/L. Catalytic ozonation with the prepared cerium oxide (CeO 2 )/granular activated carbon catalyst significantly enhances wastewater biodegradability and reduces wastewater microtoxicity. The results show that, under the optimum conditions, the removal efficiencies of COD and suspended solids are averagely 99.3% and 95.6%, respectively, and the quality of final effluent can meet the national discharge standard of China. The coagulation and ASBR processes remove a considerable proportion of organic matter, while the SBR plays an important role in post-polish of final effluent. The ecotoxicity of the wastewater is greatly reduced after undergoing the hybrid treatment. This work demonstrates that the hybrid system has the potential to be applied for the advanced treatment of high-strength industrial wastewater.

Characterization of Solidifiers used for Oil Spill Remediation ...

EPA Pesticide Factsheets

The physical characteristics and chemical composition of oil spill solidifiers were studied, and correlation of these properties with product effectiveness enabled determination of characteristics that are desirable in a good solidifier. The analyses revealed that the commercial products were primarily comprised of organic polymers and a few trace elements. A natural sorbent, which was composed entirely of plant based matter, was also evaluated, and it had the highest oil removal capacity, but it did not produce a solid mat-like final product. Generally, solidifiers with a carbonate group, pore size greater than 5 µm, and bulk densities lower than 0.3 g cm-3 were found to have better efficiency and produced a cohesive rubbery final product that facilitated removal compared to sorbents. The importance of bulk density and pore size in the performance of the solidifier suggest that the primary mechanism of action was likely physical sorption. In this study, we focused on characterizing the 12 solidifiers by using different analytical techniques.

Paradigms of mangroves in treatment of anthropogenic wastewater pollution.

PubMed

Ouyang, Xiaoguang; Guo, Fen

2016-02-15

Mangroves have been increasingly recognized for treating wastewater from aquaculture, sewage and other sources with the overwhelming urbanization trend. This study clarified the three paradigms of mangroves in disposing wastewater contaminants: natural mangroves, constructed wetlands (including free water surface and subsurface flow) and mangrove-aquaculture coupling systems. Plant uptake is the common major mechanism for nutrient removal in all the paradigms as mangroves are generally nitrogen and phosphorus limited. Besides, sediments accrete and provide substrates for microbial activities, thereby removing organic matter and nutrients from wastewater in natural mangroves and constructed wetlands. Among the paradigms, the mangrove-aquaculture coupling system was determined to be the optimal alternative for aquaculture wastewater treatment by multi-criterion decision making. Sensitivity analysis shows variability of alternative ranking but underpins the coupling system as the most environment-friendly and cost-efficient option. Mangrove restoration is expected to be achievable if aquaculture ponds are planted with mangrove seedlings, creating the coupling system. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of COD/SO4(2-) ratio on anaerobic treatment of landfill leachate during the start-up period.

PubMed

Yilmaz, Tuba; Erdirencelebi, Dilek; Berktay, Ali

2012-01-01

This study investigates the performance of an anaerobic baffled reactor (ABR) during the start-up period of raw young landfill leachate treatment at two chemical oxygen demand (COD) to SO4(2-) ratios of 20 and 4. The reactor was operated at ambient temperature and low organic loading rates (0.52, 0.76 and 1.05 kg COD/m3 per day). During the study, sulfate-reducing bacteria (SRB) activity increased at the lower ratio of COD/SO4(2-) producing higher levels of sulfide and alkalinity. The dissolved sulfide concentration reached an inhibitory level above 250 mg/L, which caused a sharp reduction in the total COD removal efficiency from 77-80% to 32%. Total volatile fatty acid (TVFA) production proceeded at a constant level despite increased organic loading. As the effluent total and organic COD concentrations increased, the inhibitory effect of the inborn sulfide was correlated to the limitation experienced in the hydrolysis/acidogenesis stages, and thus VFA production and organic matter removal.

Filter-based control of particulate matter from a lean gasoline direct injection engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, II, James E; Lewis Sr, Samuel Arthur; DeBusk, Melanie Moses

New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDImore » PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal. In addition, lean GDI engine exhaust temperatures are generally higher than diesel engines which results in more continuous regeneration of the GPF and less presence of the soot cake layer common to diesel particulate filters. Since the soot layer improves filtration efficiency, this distinction is important to consider. Research on the emission control of PM from a lean GDI engine with a GPF was conducted on an engine dynamometer. PM, after dilution, was characterized with membrane filters, organic vs. elemental carbon characterization, and size distribution techniques at various steady state engine speed and load points. The engine was operated in three primary combustion modes: stoichiometric, lean homogeneous, and lean stratified. In addition, rich combustion was utilized to simulate PM from engine operation during active regeneration of lean NOx control technologies. High (>95%) PM filtration efficiencies were observed over a wide range of conditions; however, some PM was observed to slip through the GPF at high speed and load conditions. The PM characterization at various engine speeds and loads will help enable optimized GPF design and control to achieve more fuel efficient lean GDI vehicles with low PM emissions.« less

Assessment of the nutrient removal effectiveness of floating treatment wetlands applied to urban retention ponds.

PubMed

Wang, Chih-Yu; Sample, David J

2014-05-01

The application of floating treatment wetlands (FTWs) in point and non-point source pollution control has received much attention recently. Although the potential of this emerging technology is supported by various studies, quantifying FTW performance in urban retention ponds remains elusive due to significant research gaps. Actual urban retention pond water was utilized in this mesocosm study to evaluate phosphorus and nitrogen removal efficiency of FTWs. Multiple treatments were used to investigate the contribution of each component in the FTW system with a seven-day retention time. The four treatments included a control, floating mat, pickerelweed (Pontederia cordata L.), and softstem bulrush (Schoenoplectus tabernaemontani). The water samples collected on Day 0 (initial) and 7 were analyzed for total phosphorus (TP), total particulate phosphorus, orthophosphate, total nitrogen (TN), organic nitrogen, ammonia nitrogen, nitrate-nitrite nitrogen, and chlorophyll-a. Statistical tests were used to evaluate the differences between the four treatments. The effects of temperature on TP and TN removal rates of the FTWs were described by the modified Arrhenius equation. Our results indicated that all three FTW designs, planted and unplanted floating mats, could significantly improve phosphorus and nitrogen removal efficiency (%, E-TP and E-TN) compared to the control treatment during the growing season, i.e., May through August. The E-TP and E-TN was enhanced by 8.2% and 18.2% in the FTW treatments planted with the pickerelweed and softstem bulrush, respectively. Organic matter decomposition was likely to be the primary contributor of nutrient removal by FTWs in urban retention ponds. Such a mechanism is fostered by microbes within the attached biofilms on the floating mats and plant root surfaces. Among the results of the four treatments, the FTWs planted with pickerelweed had the highest E-TP, and behaved similarly with the other two FTW treatments for nitrogen removal during the growth period. The temperature effects described by the modified Arrhenius equation revealed that pickerelweed is sensitive to temperature and provides considerable phosphorus removal when water temperature is greater than 25 °C. However, the nutrient removal effectiveness of this plant species may be negligible for water temperatures below 15 °C. The study also assessed potential effects of shading from the FTW mats on water temperature, DO, pH, and attached-to-substrate periphyton/vegetation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of organic loading rate on reactor performance and archaeal community structure in mesophilic anaerobic digesters treating municipal sewage sludge.

PubMed

Gómez, Eddie; Martin, Jay; Michel, Frederick C

2011-11-01

In this study, the organic loading rate (OLR) of a high-solids anaerobic digestion (HSAD) system was increased from 3.4 to 5.0 gVS L(-1) day(-1) and reactor stability, performance and microbial community structure were determined. Laboratory simulations (3.5 L) of the full-scale process (500 dry ton year(-1)) were conducted using continuously stirred-tank mesophilic reactors. OLRs of 3.4 gVS L(-1)day(-1) (equal to the full-scale HSAD), 4.0, 4.5 and 5.0 gVS L(-1)day(-1) were evaluated. Biochemical parameters and archaeal community dynamics were measured over 42 days of steady state operation. Results showed that increasing OLR increased the amount of organic matter conversion and resulted in higher organic matter removal and volumetric methane (CH₄) production (VMP) rates. The highest volatile solids (VS) removal and VMP results of 54 ± 2% and 1.4 ± 0.1 L CH₄ L(-1)day(-1) were observed for 5.0 gVS L(-1) day(-1). The efficiency of reactor conversion of organic matter to CH(4) was found to be similar in all the treatments with an average value of 0.57 ± 0.07 LCH(4) gVS(-1) (removed). 16S rRNA gene terminal restriction fragment polymorphism (T-RFLP) analyses revealed that archaeal TRFs remained stable during the experiment accounting for an average relative abundance (RA) of 81 ± 1%. Archaea consistent with multiple terminal restriction fragments (TRFs) included members of the Euryarchaeota and Crenarchaeota phyla, including acetoclastic and hydrogenotrophic groups. In conclusion, this laboratory-scale study suggests that performance and stability as well as the archaeal community structure in this HSAD system was unaffected by increasing the OLR by nearly 50% and that this increase resulted in a similar increase in the amount of CH(4) gas generated.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology.

PubMed

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium. Copyright © 2017 Elsevier B.V. All rights reserved.

Removal of humic acid by a new type of electrical hollow-fiber microfiltration (E-HFMF)

NASA Astrophysics Data System (ADS)

Shang, Ran; Deng, Hui-ping; Hu, Jing-yi

2010-11-01

Low pressure membrane filtration, such as microfiltration, was widely used in the field of drinking water purification in the past few decades. Traditional microfiltration membranes are not efficient enough in the removal of natural organic matters (NOM) from raw water. Moreover, they tend to be fouled by the NOM and the filtration age of the membranes is thus shrinked. To tackle these problems, a new type of electrical hollow-fiber microfiltration module (E-HFMF) was designed. In the E-HFMF module, the hollow-fiber microfiltration membranes were placed into the radialized electrical field which functioned from the centre to the exterior of the cylindrical cavity. The main goal of the present study was to evaluate the efficiency of E-HFMF to remove the humic acid (HA, one of the main components of NOM). According to the parallel tests compared with the traditional microfiltration, the removal rate of humic acid was raised to 70%˜85% in terms of UV-254 and to 60%˜75% in terms of DOC when filtrating with the E-HFMF, while the removal rates of humic acid were 10%˜20% and 1%˜10% respectively when filtrating with the traditional microfiltration. The negative charged humic acid moved to the anode because of the electrophoresis, so few humic acid could be able to permeate through the membrane. The electrophoresis mobility of the humic acid permeating through the traditional microfiltration decreased by 19%, while the same index from the E-HFMF decreased by 75%. This indicated that the electrophoresis played a significant role on removing the humic acid. According to the gel permeate chromatograph analysis, humic acid aggregated in an electric field and thus forms loose and permeable cake layer on the membrane surface, which also relieved membrane fouling. Meanwhile, the negative charged humic acid migrating to the anode at the center minimized the deposition onto the membrane surface, and eliminated the membrane fouling as a result. During the E-HFMF filtration, the humic acid was not oxidized observably in the electrical field, according to the FT-IR analysis.

Effects of operation parameters on nutrient removal from wastewater and high-protein biomass production in a duckweed-based (Lemma aequinoctialis) pilot-scale system.

PubMed

Zhao, Yonggui; Fang, Yang; Jin, Yanling; Huang, Jun; Bao, Shu; He, Zhiming; Wang, Feng; Zhao, Hai

2014-01-01

The effects of water depth, coverage rate and harvest regime on nutrient removal from wastewater and high-protein biomass production were assessed in a duckweed-based (Lemna aequinoctialis) pilot-scale wastewater treatment system (10 basins × 12 m(2)) that is located near Dianchi Lake in China. The results indicated that a water depth of 50 cm, a coverage rate of 150% and a harvest regime of 4 days were preferable conditions, under which excellent records of high-protein duckweed (dry matter production of 6.65 g/m(2)/d with crude protein content of 36.16% and phosphorus content of 1.46%) were obtained at a temperature of 12-21 °C. At the same time, the system achieved a removal efficiency of 66.16, 23.1, 48.3 and 76.52% for NH4(+)-N, TN, TP and turbidity, respectively, with the considerable removal rate of 0.465 g/m(2)/d for TN and 0.134 g/m(2)/d for TP at a hydraulic retention time of 6 days. In additionally, it was found that a lower duckweed density could lead to higher dissolved oxygen in the water and then a higher removal percentage of NH4(+)-N by nitrobacteria. This study obtains the preferable operation conditions for wastewater treatment and high-protein biomass production in a duckweed-based pilot-scale system, supplying an important reference for further large-scale applications of duckweed.

Removal of viruses from sewage, effluents, and waters

PubMed Central

Berg, Gerald

1973-01-01

Because large variations occur in the concentrations of viruses that enter treatment plants from season to season and from place to place, and even during a 24-hour period, field studies on the removal of viruses by treatment processes require temporal coordination of sampling. Quantitative methods for concentrating viruses must be developed to measure accurately the efficiency of virus removal by treatment processes in field situations. Extended settling, and storage of sewage and raw waters, reduce virus levels and deserve further study. Oxidation ponds must be reevaluated with regard to temporal matching of influent and effluent samples and with special care to prevent short-circuiting. Conventional and modified activated sludge plants must be reassessed with temporal matching of samples. Coagulation of viruses with metal ions requires field evaluation, and virus removal by filtration through sand and other media, under constant salt and organic loadings, needs both laboratory and field evaluation. A comparative study of water disinfectants related to specific conditions is needed. The toxicity, carcinogenicity, and teratogenicity of products resulting from disinfection must also be assessed. Other matters for investigation are: methods for quantitatively detecting viruses adsorbed on solids, the virus-removal capability of soils, better virus indicators, virus concentration in shellfish, the frequency of infection in man brought about by swallowing small numbers of viruses in water, the epidemiology of virus infection in man by the water route, the effect of viruses of nonhuman origin on man, and the occurrence of tumour-inducing agents in water. PMID:4547291

Adsorption of SO2 and NO from incineration flue gas onto activated carbon fibers.

PubMed

Liu, Zhen-Shu

2008-11-01

Activated carbon fibers (ACFs) were used to remove SO2 and NO from incineration flue gas. Three types of ACFs in their origin state and after pretreatment with HNO3, NaOH, and KOH were investigated. The removal efficiencies of SO2 and NO were determined experimentally at defined SO2 and NO concentrations and at temperatures of 150, 200 and 260 degrees C. Experimental results indicated that the removal efficiencies of SO2 and NO using the original ACFs were < 56% and < 27%, respectively. All ACFs modified with HNO3, NaOH, and KOH solution could increase the removal efficiencies of SO(2) and NO. The mesopore volumes and functional groups of ACFs are important in determining the removal of SO2 and NO. When the mesopore volumes of the ACFs are insufficient for removing SO2 and NO, the functional groups on the ACFs are not important in determining the removal of SO2 and NO. On the contrary, the effects of the functional groups on the removal of SO2 and NO are more important than the mesopore volumes as the amount of mesopores on the ACFs is sufficient to remove SO2 and NO. Moreover, the removal efficiencies of SO2 and NO were greatest at 200 degrees C. When the inlet concentration of SO2 increased to 600 ppm, the removal efficiency of SO2 increased slightly and the removal efficiency of NO decreased.

Removal of Cu2+ and turbidity from wastewater by mercaptoacetyl chitosan.

PubMed

Chang, Qing; Zhang, Min; Wang, Jinxi

2009-09-30

A macromolecule heavy metal flocculant mercaptoacetyl chitosan (MAC) was prepared by reacting chitosan with mercaptoacetic acid. In preliminary experiments, the flocculation performance of MAC was evaluated by using wastewater containing Cu(2+) or/and turbidity. Some factors which affect the removal of Cu(2+) and turbidity were also studied. The experimental results showed that: (1) MAC can remove both Cu(2+) and turbidity from wastewater. The removal efficiency of Cu(2+) by using MAC combined with hydrolyzed polyacrylamide is higher than that by only using MAC, the removal efficiency of Cu(2+) reaches above 98%; (2) when water sample containing not only Cu(2+) but also turbidity-causing substance, the removal efficiency of both Cu(2+) and turbidity will be promoted by the cooperation effect of each other, the residual concentration of Cu(2+) reaches below 0.5 mg L(-1) and the turbidity reaches below 3NTU, Cu(2+) is more easily removed by MAC when turbidity is higher; (3) the removal efficiency of Cu(2+) increases with the increase in pH value, contrarily removal efficiency of turbidity decreases with the increase in pH value.

Enhancing rain garden design to promote nitrate removal: testing a media carbon amendment.

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, in particular heavy metals, phosphorus, and oil and grease, but in most cases they show much smaller removal rates of nitrate. This is likely due to the high sand and low organic matter content specified for rain ga...

Enhancing Rain Garden Design to Promote Nitrate Removal: Testing a media carbon amendment

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, in particular heavy metals, phosphorus, and oil and grease, but in most cases they show much smaller removal rates of nitrate. This is likely due to the high sand and low organic matter content specified for rain ga...

Decoupling of magnetic fields in collapsing protostellar envelopes and disc formation and fragmentation

NASA Astrophysics Data System (ADS)

Zhao, Bo; Caselli, Paola; Li, Zhi-Yun; Krasnopolsky, Ruben

2018-02-01

Efficient magnetic braking is a formidable obstacle to the formation of rotationally supported discs (RSDs) around protostars in magnetized dense cores. We have previously shown, through 2D (axisymmetric) non-ideal magnetohydrodynamic simulations, that removing very small grains (VSGs: ∼10 Å to few 100 Å) can greatly enhance ambipolar diffusion and enable the formation of RSDs. Here, we extend the simulations of disc formation enabled by VSG removal to 3D. We find that the key to this scenario of disc formation is that the drift velocity of the magnetic field almost cancels out the infall velocity of the neutrals in the 102-103 au scale 'pseudo-disc' where the field lines are most severely pinched and most of protostellar envelope mass infall occurs. As a result, the bulk neutral envelope matter can collapse without dragging much magnetic flux into the disc-forming region, which lowers the magnetic braking efficiency. We find that the initial discs enabled by VSG removal tend to be Toomre-unstable, which leads to the formation of prominent spiral structures that function as centrifugal barriers. The piling-up of infall material near the centrifugal barrier often produces dense fragments of tens of Jupiter masses, especially in cores that are not too strongly magnetized. Some fragments accrete on to the central stellar object, producing bursts in mass accretion rate. Others are longer lived, although whether they can survive for a long term to produce multiple systems remains to be ascertained. Our results highlight the importance of dust grain evolution in determining the formation and properties of protostellar discs and potentially multiple systems.

The impact of pH on floc structure characteristic of polyferric chloride in a low DOC and high alkalinity surface water treatment.

PubMed

Cao, Baichuan; Gao, Baoyu; Liu, Xin; Wang, Mengmeng; Yang, Zhonglian; Yue, Qinyan

2011-11-15

The adjustment of pH is an important way to enhance removal efficiency in coagulation units, and in this process, the floc size, strength and structure can be changed, influencing the subsequent solid/liquid separation effect. In this study, an inorganic polymer coagulant, polyferric chloride (PFC) was used in a low dissolved organic carbon (DOC) and high alkalinity surface water treatment. The influence of coagulation pH on removal efficiency, floc growth, strength, re-growth capability and fractal dimension was examined. The optimum dosage was predetermined as 0.150 mmol/L, and excellent particle and organic matter removal appeared in the pH range of 5.50-5.75. The structure characteristics of flocs formed under four pH conditions were investigated through the analysis of floc size, effect of shear and particle scattering properties by a laser scattering instrument. The results indicated that flocs formed at neutral pH condition gave the largest floc size and the highest growth rate. During the coagulation period, the fractal dimension of floc aggregates increased in the first minutes and then decreased and larger flocs generally had smaller fractal dimensions. The floc strength, which was assessed by the relationship of floc diameter and velocity gradient, decreased with the increase of coagulation pH. Flocs formed at pH 4.00 had better recovery capability when exposed to lower shear forces, while flocs formed at neutral and alkaline conditions had better performance under higher shear forces. Copyright © 2011 Elsevier Ltd. All rights reserved.

Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?

PubMed

Kocatürk-Schumacher, Nazlı Pelin; Zwart, Kor; Bruun, Sander; Brussaard, Lijbert; Jensen, Lars Stoumann

2017-05-01

Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium, orthophosphate and dissolved organic carbon (DOC) from the liquid fraction of digestate. Our objectives were to investigate the effect of the initial loading ratio between liquid and biochar on nutrient removal, and to investigate the effect of combining biochar with clinoptilolite on nutrient and DOC removal efficiency. Increasing the initial loading ratios increased nutrient concentrations on biochar to 8.61 mg NH 4 -N g -1 , 1.95 mg PO 4 -P g -1 and 13.01 mg DOC g -1 , but resulted in decreasing removal efficiencies. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and DOC removal efficiencies compared to biochar alone, but did not significantly change PO 4 -P removal efficiencies. Removal efficiencies with combined sorbents were up to 67% for ammonium, 58% for DOC and 58% for potassium. Clinoptilolite showed higher removal efficiencies compared to biochar alone, and combining clinoptilolite with biochar improved only total P removal efficiency. Concentrating nutrients with clinoptilolite and biochar may be an option when both sorbents are available at low cost.

Apparatus for removal of particulate matter from gas streams

DOEpatents

Smith, Peyton L.; Morse, John C.

2000-01-01

An apparatus for the removal of particulate matter from the gaseous product stream of an entrained flow coal gasifier which apparatus includes an initial screen, an intermediate screen which is aligned with the direction of flow of the gaseous product stream and a final screen transversely disposed to the flow of gaseous product and which apparatus is capable of withstanding at least a pressure differential of about 10 psi (68.95 kPa) or greater at the temperatures of the gaseous product stream.

20 CFR 410.656 - Removal of hearing to Appeals Council.

Code of Federal Regulations, 2010 CFR

2010-04-01

... SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Determinations of Disability, Other... hearing pending before an Administrative Law Judge. The hearing on any matter so removed to the Appeals...

20 CFR 410.656 - Removal of hearing to Appeals Council.

Code of Federal Regulations, 2011 CFR

2011-04-01

... SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Determinations of Disability, Other... hearing pending before an Administrative Law Judge. The hearing on any matter so removed to the Appeals...

Anaerobic/aerobic treatment of a petrochemical wastewater from two aromatic transformation processes by fluidized bed reactors.

PubMed

Estrada-Arriaga, Edson B; Ramirez-Camperos, Esperanza; Moeller-Chavez, Gabriela E; García-Sanchez, Liliana

2012-01-01

An integrated fluidized bed reactor (FBR) has been employed as the treatment for petrochemical industry wastewaters with high organic matter and aromatic compounds, under anaerobic and aerobic conditions. The system was operated at hydraulic residence time (HRT) of 2.7 and 2.2 h in the anaerobic and aerobic reactor, respectively. The degree of fluidization in the beds was 30%. This system showed a high performance on the removal of organic matter and aromatic compounds. At different organic loading rates (OLR), the chemical oxygen demand (COD) removal in the anaerobic reactor was close to 85% and removals of the COD up to 94% were obtained in the aerobic reactor. High removals of benzene, toluene, ethylbenzene, xylenes, styrene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene and naphthalene were achieved in this study.

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

DOE PAGES

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.; ...

2017-11-24

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Short tests to couple N₂O emission mitigation and nitrogen removal strategies for landfill leachate recirculation.

PubMed

Wu, Dong; Wang, Chao; Dolfing, Jan; Xie, Bing

2015-04-15

Landfills implemented with onsite leachate recirculation can efficiently remove pollutants, but currently they are reckoned as N2O emission hot spots. In this project, we evaluated the relationship between N2O emission and nitrogen (N) removal efficiency with different types of leachate recirculated. Nitrate supplemented leachate showed low N2O emission rates with the highest N removal efficiency (~70%), which was equivalent to ~1% nitrogen emitted as N2O. Although in nitrite containing leachates' N removal efficiencies also reached to ~60%, their emitted N2O comprised ~40% of total removed nitrogen. Increasing nitrogen load promoted N2O emission and N removal efficiency, except in ammonia type leachate. When the ratio of BOD to total nitrogen increased from 0.2 to 0.4, the N2O emission flux from nitrate supplemented leachate decreased from ~25 to <0.5 μg N/kg-soil·h. We argue prior to leachate in situ recirculation, sufficient pre-aeration is critical to mitigate N2O surges and simultaneously enhance nitrogen removal efficiency. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 63.4566 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4566 Section 63.4566 Protection of Environment... efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test required by § 63.4560...

40 CFR 63.4566 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.4566 Section 63.4566 Protection of Environment... efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test required by § 63.4560...

Analyzing the cost effectiveness of Santiago, Chile's policy of using urban forests to improve air quality.

PubMed

Escobedo, Francisco J; Wagner, John E; Nowak, David J; De la Maza, Carmen Luz; Rodriguez, Manuel; Crane, Daniel E

2008-01-01

Santiago, Chile has the distinction of having among the worst urban air pollution problems in Latin America. As part of an atmospheric pollution reduction plan, the Santiago Regional Metropolitan government defined an environmental policy goal of using urban forests to remove particulate matter less than 10 microm (PM(10)) in the Gran Santiago area. We used cost effectiveness, or the process of establishing costs and selecting least cost alternatives for obtaining a defined policy goal of PM(10) removal, to analyze this policy goal. For this study, we quantified PM(10) removal by Santiago's urban forests based on socioeconomic strata and using field and real-time pollution and climate data via a dry deposition urban forest effects model. Municipal urban forest management costs were estimated using management cost surveys and Chilean Ministry of Planning and Cooperation documents. Results indicate that managing municipal urban forests (trees, shrubs, and grass whose management is under the jurisdiction of Santiago's 36 municipalities) to remove PM(10) was a cost-effective policy for abating PM(10) based on criteria set by the World Bank. In addition, we compared the cost effectiveness of managing municipal urban forests and street trees to other control policies (e.g. alternative fuels) to abate PM(10) in Santiago and determined that municipal urban forest management efficiency was similar to these other air quality improvement measures.

Role of UASBs in River Water Quality Conservation in India

NASA Astrophysics Data System (ADS)

Gali, Veeresh; Thakur, Manisha; Gupta, Ashok Kumar; Ganguly, Rajiv

2018-03-01

Appropriate low-cost treatment technologies are a prerequisite for sound management of natural water resources against pollution in developing countries. Among the existing technologies available, UASB is found to be economically viable for India when considering all factors including operation and maintenance cost and treatment efficiency. However, this technology suffers setbacks in meeting the effluent guidelines prescribed by the government of India. Post treatment is supplemental to this process to meet the effluent standards in terms of removal of organic matter, suspended solids, pathogens and nutrients. Recent stringent effluent guidelines notified by the Ministry of Environment, Forests and Climate Change, Government of India has further reduced the limits of BOD by 3 times, COD and TSS by 5 times, NH4-N and total Nitrogen by 10 times as compared to the previous guidelines. Fecal Coliforms has been specified as <100MPN/100mL. In this paper, the present scenario of UASB based STPs and their role in river conservation is reviewed against the backdrop of stringent effluent guidelines. The minimum removal rates of BOD, COD and TSS in these plants are around 42 - 44% and the average removal rates are reported to be 66%, 61% and 65% respectively. The enhanced removal of BOD (97%), COD (98%) and TSS has been reported in STPs in conjunction with post treatment facilities such as facultative aerated lagoons, aeration tanks and polishing ponds.

A comparative study of ozonation, iron coated zeolite catalyzed ozonation and granular activated carbon catalyzed ozonation of humic acid.

PubMed

Gümüş, Dilek; Akbal, Feryal

2017-05-01

This study compares ozonation (O 3 ), iron coated zeolite catalyzed ozonation (ICZ-O 3 ) and granular activated carbon catalyzed ozonation (GAC-O 3 ) for removal of humic acid from an aqueous solution. The results were evaluated by the removal of DOC that specifies organic matter, UV 254 absorbance, SUVA (Specific Ultraviolet Absorbance at 254 nm) and absorbance at 436 nm. When ozonation was used alone, DOC removal was 21.4% at an ozone concentration of 10 mg/L, pH 6.50 and oxidation time of 60 min. The results showed that the use of ICZ or GAC as a catalyst increased the decomposition of humic acid compared to ozonation alone. DOC removal efficiencies were 62% and 48.1% at pH 6.5, at a catalyst loading of 0.75 g/L, and oxidation time of 60 min for ICZ and GAC, respectively. The oxidation experiments were also carried out using <100 kDa and <50 kDa molecular size fractions of humic acid in the presence of ICZ or GAC. Catalytic ozonation also yielded better DOC and UV 254 reduction in both <50 kDa and <100 kDa fractions of HA compared to ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kinetic Study of Hydroxyl and Sulfate Radical-Mediated Oxidation of Pharmaceuticals in Wastewater Effluents.

PubMed

Lian, Lushi; Yao, Bo; Hou, Shaodong; Fang, Jingyun; Yan, Shuwen; Song, Weihua

2017-03-07

Advanced oxidation processes (AOPs), such as hydroxyl radical (HO • )- and sulfate radical (SO 4 •- )-mediated oxidation, are alternatives for the attenuation of pharmaceuticals and personal care products (PPCPs) in wastewater effluents. However, the kinetics of these reactions needs to be investigated. In this study, kinetic models for 15 PPCPs were built to predict the degradation of PPCPs in both HO • - and SO 4 •- -mediated oxidation. In the UV/H 2 O 2 process, a simplified kinetic model involving only steady state concentrations of HO • and its biomolecular reaction rate constants is suitable for predicting the removal of PPCPs, indicating the dominant role of HO • in the removal of PPCPs. In the UV/K 2 S 2 O 8 process, the calculated steady state concentrations of CO 3 •- and bromine radicals (Br • , Br 2 •- and BrCl •- ) were 600-fold and 1-2 orders of magnitude higher than the concentrations of SO 4 •- , respectively. The kinetic model, involving both SO 4 •- and CO 3 •- as reactive species, was more accurate for predicting the removal of the 9 PPCPs, except for salbutamol and nitroimidazoles. The steric and ionic effects of organic matter toward SO 4 •- could lead to overestimations of the removal efficiencies of the SO 4 •- -mediated oxidation of nitroimidazoles in wastewater effluents.

High-rate wastewater treatment combining a moving bed biofilm reactor and enhanced particle separation.

PubMed

Helness, H; Melin, E; Ulgenes, Y; Järvinen, P; Rasmussen, V; Odegaard, H

2005-01-01

Many cities around the world are looking for compact wastewater treatment alternatives since space for treatment plants is becoming scarce. In this paper development of a new compact, high-rate treatment concept with results from experiments in lab-scale and pilot-scale are presented. The idea behind the treatment concept is that coagulation/floc separation may be used to separate suspended and colloidal matter (resulting in > 70% organic matter removal in normal wastewater) while a high-rate biofilm process (based on Moving Bed biofilm reactors) may be used for removing low molecular weight, easily biodegradable, soluble organic matter. By using flotation for floc/biomass separation, the total residence time for a plant according to this concept will normally be < 1 hour. A cationic polymer combined with iron is used as coagulant at low dosages (i.e. 1-2 mg polymer/l, 5-10 mg Fe/l) resulting in low sludge production (compared to conventional chemical treatment) and sufficient P-removal.

Method for producing and treating coal gases

DOEpatents

Calderon, Albert

1990-01-01

A method of generating a de-sulphurized volatile matter and a relatively low Btu gas includes the initial step of pyrolyzing coal to produce volatile matter and a char. The volatile matter is fed to a first de-sulphurizer containing a de-sulphurizing agent to remove sulphur therefrom. At the same time, the char is gasified to produce a relatively low Btu gas. The low Btu gas is fed to a second de-sulphurizer containing the de-sulphurizing agent to remove sulphur therefrom. A regenerator is provided for removing sulphur from the de-sulphurizing agent. Portions of the de-sulphurizing agent are moved among the first de-sulphurizer, the second de-sulphurizer, and the regenerator such that the regenerator regenerates the de-sulphurizing agent. Preferably, the portions of the de-sulphurizing agent are moved from the second de-sulphurizer to the first de-sulphurizer, from the first de-sulphurizer to the regenerator, and from the regenerator to the second de-sulphurizer.

Investigation of ozone and peroxone impacts on natural organic matter character and biofiltration performance using fluorescence spectroscopy.

PubMed

Peleato, Nicolás M; Sidhu, Balsher Singh; Legge, Raymond L; Andrews, Robert C

2017-04-01

Impacts of ozonation alone as well as an advanced oxidation process of ozone plus hydrogen peroxide (H 2 O 2  + O 3 ) on organic matter prior to and following biofiltration were studied at pilot-scale. Three biofilters were operated in parallel to assess the effects of varying pre-treatment types and dosages. Conventionally treated water (coagulation/flocculation/sedimentation) was fed to one control biofilter, while the remaining two received water with varying applied doses of O 3 or H 2 O 2  + O 3 . Changes in organic matter were characterized using parallel factors analysis (PARAFAC) and fluorescence peak shifts. Intensities of all PARAFAC components were reduced by pre-oxidation, however, individual humic-like components were observed to be impacted to varying degrees upon exposure to O 3 or H 2 O 2  + O 3 . While the control biofilter uniformly reduced fluorescence of all PARAFAC components, three of the humic-like components were produced by biofiltration only when pre-oxidation was applied. A fluorescence red shift, which occurred with the application of O 3 or H 2 O 2  + O 3 , was attributed to a relative increase in carbonyl-containing components based on previously reported results. A subsequent blue shift in fluorescence caused by biofiltration which received pre-oxidized water indicated that biological treatment readily utilized organics produced by pre-oxidation. The results provide an understanding as to the impacts of organic matter character and pre-oxidation on biofiltration efficiency for organic matter removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Colored dissolved organic matter in Tampa Bay, Florida

USGS Publications Warehouse

Chen, Z.; Hu, C.; Conmy, R.N.; Muller-Karger, F.; Swarzenski, P.

2007-01-01

Absorption and fluorescence of colored dissolved organic matter (CDOM) and concentrations of dissolved organic carbon (DOC), chlorophyll and total suspended solids in Tampa Bay and its adjacent rivers were examined in June and October of 2004. Except in Old Tampa Bay (OTB), the spatial distribution of CDOM showed a conservative relationship with salinity in June, 2004 (aCDOM(400) = − 0.19 × salinity + 6.78, R2 = 0.98, n = 17, salinity range = 1.1–32.5) with little variations in absorption spectral slope and fluorescence efficiency. This indicates that CDOM distribution was dominated by mixing. In October, 2004, CDOM distribution was nonconservative with an average absorption coefficient (aCDOM(400), ∼ 7.76 m-1) about seven times higher than that in June (∼ 1.11 m-1). The nonconservative behavior was caused largely by CDOM removal at intermediate salinities (e.g., aCDOM(400) removal > 15% at salinity ∼ 13.0), which likely resulted from photobleaching due to stronger stratification. The spatial and seasonal distributions of CDOM in Tampa Bay showed that the two largest rivers, the Alafia River (AR) and Hillsborough River (HR) were dominant CDOM sources to most of the bay. In OTB, however, CDOM showed distinctive differences: lower absorption coefficient, higher absorption spectral slopes, and lower ratios of CDOM absorption to DOC and higher fluorescence efficiency. These differences may have stemmed from (1) changes in CDOM composition by more intensive photobleaching due to the longer residence time of water mass in OTB; (2) other sources of CDOM than the HR/AR inputs, such as local creeks, streams, groundwater, and/or bottom re-suspension. Average CDOM absorption in Tampa Bay at 443 nm, aCDOM(443), was about five times higher in June and about ten times higher in October than phytoplankton pigment absorption, aph(443), indicating that blue light attenuation in the water column was dominated by CDOM rather than by phytoplankton absorption throughout the year.

Addition of anaerobic tanks to an oxidation ditch system to enhance removal of phosphorus from wastewater.

PubMed

Liu, Jun-xin; van Groenestijn, J W; Doddema, H J; Wang, Bao-zhen

2002-04-01

The oxidation ditch has been used for many years all over the world as an economic and efficient wastewater treatment technology. It can remove COD, nitrogen and a part of phosphorus efficiently. In the experiment described, a pilot scale Pasveer oxidation ditch system has been tested to investigate the removal of phosphorus from wastewater. The experimental results showed that influent total phosphorus(TP) was removed for 35%-50%. After this, two anaerobic tanks with total volume of 11 m3 were added to the system to release phosphorus. As a result, the TP removal efficiency increased by about 20%. At an anaerobic HRT of about 6 hours, a TP removal efficiency of 71% was achieved.

Efficiency of removal of cadmium from aqueous solutions by plant leaves and the effects of interaction of combinations of leaves on their removal efficiency.

PubMed

Salim, R; Al-Subu, M; Dawod, E

2008-05-01

Removal of cadmium from aqueous solutions using 20 species of plant leaves and combinations of these leaves have been studied. Several factors affecting the removal efficiency have been studied. The most efficient types of plant leaves for the removal of cadmium are those of styrax, plum, pomegranate and walnut. The interaction effect of the combined leaf samples on the efficiency of removal of cadmium has been found to be additive in combinations involving styrax plant leaves but seems to be antagonistic in all other combinations. The optimum experimental conditions for removal of cadmium have been found to be at pH 4.1, using high concentrations of naturally dried plant leaves, using ground leaves and to remove cadmium from agitated aqueous solutions. The percentage of metal removed at an initial cadmium concentration of 10mg/l by the most efficient types of leaves have been found to be 85% for styrax leaves, 85% for plum leaves, 80% for pomegranate leaves, 78% for walnut leaves and 77% for meddler leaves. The presence of foreign ions or complexing agents has been found to reduce the efficiency of removal of cadmium by plant leaves. About 80-85% of the cadmium in charged plant leaves has been released under the influence of changing the pH of the solution, addition of competing ions and the addition of EDTA. The results of removal of cadmium by plant leaves have been found to follow the Freundlich adsorption isotherm, first-order reaction with respect to cadmium and to have intra-pore diffusion as the rate-limiting step.

Monitoring of electrokinetic removal of heavy metals in tailing-soils using sequential extraction analysis.

PubMed

Kim, S O; Kim, K W

2001-08-17

This research focused on the monitoring of the electrokinetic removal of heavy metals from tailing-soils, and emphasizes the dependency of removal efficiencies upon their physico-chemical states, as demonstrated by the different extraction methods adopted, which included aqua regia and sequential extraction. The tailing-soils examined contained high concentrations of target metal contaminants (Cd=179mgkg(-1), Cu=207mgkg(-1), Pb=5175mgkg(-1), and Zn=7600mgkg(-1)). The removal efficiencies of the different metals were significantly influenced by their speciations, mobilities and affinities (adsorption capacities) in the soil matrix. The removal efficiencies of mobile and weakly bound fractions, such as the exchangeable fraction were more than 90% by electrokinetic treatment, but strongly bound fractions, such as the organically bound species and residual fraction were not significantly removed (less than 30% removal efficiencies). In accordance with the general sequence of mobilities of heavy metals in soils, the removal efficiencies of more mobile heavy metals (Cd, Cu, and Zn) were higher than that of less mobile heavy metal (Pb).

Unburnt carbon from coal fly ashes as a precursor of activated carbon for nitric oxide removal.

PubMed

Rubio, Begoña; Izquierdo, M Teresa; Mayoral, M Carmen; Bona, M Teresa; Andres, Jose M

2007-05-08

The aim of this work is to evaluate the characteristics of an activated carbon obtained from unburnt carbon in coal fly ashes to be used in the removal of NO. Carbon-rich fraction was obtained by mechanical sieving of fly ashes. The mineral matter was removed by conventional HCl and HF demineralization procedure. Activation was carried out with steam at 900 degrees C in order to develop porosity onto the sample. Characterization of samples was performed by several techniques with a main objective: to follow the mineral matter content, composition and distribution on the samples in order to better understand how to remove it from unburnt carbon in fly ashes. To study the use of this unburnt carbon as a precursor for the preparation of activated carbons for gas cleaning, the NO removal by ammonia using activated carbon as a catalyst at low temperature was performed. Results show a good performance of activated carbon in this reaction that is in relationship with BET surface area.

The effect of the textile industry dye bath additive EDTMPA on colour removal characteristics by ozone oxidation.

PubMed

Olmez, T; Kabdaşli, I; Tünay, O

2007-01-01

In this study, the effects of the phosphonic acid based sequestering agent EDTMPA used in the textile dye baths on colour and organic matter removal by ozone oxidation was experimentally investigated. Procion Navy HEXL dyestuff that has been commonly used for the reactive dyeing of cellulose fibers was selected as the model component. The organic matter oxidation by ozone was determined to obey the pseudo-first order kinetics as they are treated singly or in combination. COD removal rates obtained from pseudo-first order reaction kinetics showed that oxidation of Navy HEXL alone (0.0947 L/min) was faster than that of EDTMPA (0.0171 L/min) and EDTMPA with dye (0.0155 L/min) at pH 3.0. It was also found that reaction rates of single EDTMPA removal and EDTMPA and dye mixture removal increased as the reaction pH was increased from 3.0 to 10.5.

Wastewater treatment for nutrient removal with Ecuadorian native microalgae.

PubMed

Benítez, María Belén; Champagne, Pascale; Ramos, Ana; Torres, Andres F; Ochoa-Herrera, Valeria

2018-04-12

The aim of this project was to study the feasibility of utilizing native microalgae for the removal of nitrogen and phosphorus, as a potential secondary wastewater treatment process in Ecuador. Agitation and aeration batch experiments were conducted using synthetic secondary wastewater effluent, to determine nitrogen and phosphorus removal efficiencies by a native Ecuadorian microalgal strain. Experimental results indicated that microalgal cultures could successfully remove nitrogen and phosphorus. [Formula: see text] and [Formula: see text] removal efficiencies of 52.6 and 55.6%, and 67.0 and 20.4%, as well as [Formula: see text] production efficiencies of 87.0 and 93.1% were reported in agitation and aeration photobioreactors, respectively. Aeration was not found to increase the nutrient removal efficiency of [Formula: see text]. Moreover, in the case of [Formula: see text], a negative impact was observed, where removal efficiencies decreased by a factor of 3.3 at higher aeration rates. To the best of our knowledge, this is the first report of the removal of nutrients by native Ecuadorian Chlorella sp., hence the results of this study would indicate that this native microalgal strain could be successfully incorporated in a potential treatment process for nutrient removal in Ecuador.

Environmental impact and bioremediation of seleniferous soils and sediments.

PubMed

Wadgaonkar, Shrutika L; Nancharaiah, Yarlagadda V; Esposito, Giovanni; Lens, Piet N L

2018-01-05

Selenium concentrations in the soil environment are directly linked to its transfer in the food chain, eventually causing either deficiency or toxicity associated with several physiological dysfunctions in animals and humans. Selenium bioavailability depends on its speciation in the soil environment, which is mainly influenced by the prevailing pH, redox potential, and organic matter content of the soil. The selenium cycle in the environment is primarily mediated through chemical and biological selenium transformations. Interactions of selenium with microorganisms and plants in the soil environment have been studied in order to understand the underlying interplay of selenium conversions and to develop environmental technologies for efficient bioremediation of seleniferous soils. In situ approaches such as phytoremediation, soil amendment with organic matter and biovolatilization are promising for remediation of seleniferous soils. Ex situ remediation of contaminated soils by soil washing with benign leaching agents is widely considered for removing heavy metal pollutants. However, it has not been applied until now for remediation of seleniferous soils. Washing of seleniferous soils with benign leaching agents and further treatment of Se-bearing leachates in bioreactors through microbial reduction will be advantageous as it is aimed at removal as well as recovery of selenium for potential re-use for agricultural and industrial applications. This review summarizes the impact of selenium deficiency and toxicity on ecosystems in selenium deficient and seleniferous regions across the globe, and recent research in the field of bioremediation of seleniferous soils.

UASB-septic tank as an alternative for decentralized wastewater treatment in Mexico.

PubMed

Santiago-Díaz, Ángel L; García-Albortante, Julisa; Salazar-Peláez, Mónica L

2018-02-05

The aim of this work was to evaluate the performance of a UASB-septic tank as a decentralized treatment of high-strength municipal wastewater under two different HRTs (48 and 72 h). Thus, a lab-scale (44.85 L) UASB-septic tank constituted by three compartments was operated under HRT 72 and 48 h. Removal efficiencies of total chemical oxygen demand (COD), biological oxygen demand (BOD 5 ) and suspended solids (SS) ranged from 60% to 80% for the first two parameters and from 70% to 90% for the last one. According to the statistical analysis, it was established that decreasing HRT from 72 to 48 h did not affect the performance of the UASB-septic tank; therefore, the latter HRT is recommended to be used for operation. In the first compartment, most of the organic matter removal was carried out, while the other two compartments served as polishing. Over the course of six months, the VS concentration and VS/TS ratio in sludge blanket decreased, indicating digestion and stabilization of the retained solids. Also, an increase of 4% in sludge volume was observed; thus, time for desludging would be approximately five years. Comparison of the UASB-septic tank and the UASB reactor showed that both systems had similar performance regarding effluent concentrations of organic matter and solids. Thus, under low volumetric organic load conditions (less than 20 mg COD/L h), the former is an attractive option for municipal wastewater treatment.

Insight into the adsorption mechanisms of trace organic carbon on biological treatment process.

PubMed

Zolfaghari, Mehdi; Drogui, Patrick; Brar, Satinder Kaur; Buelna, Gerardo; Dubé, Rino

2017-09-01

The presence of recalcitrant dissolved organic matter (DOM) could have a significant effect on the adsorption mechanism and capacity of the sludge for many trace organic carbons (TrOCs). In this study, adsorption of three TrOCs on the sludge and HA was investigated. The results revealed that neutral hydrophilic compounds had an insignificant interaction with both sludge and HA. Positively charged compounds, such as fluoranthene, had more affinity toward HA than sludge with solid/liquid partitioning of 57 and 3.2 L/g, respectively. The adsorption intensity (K f ) of di-2-ethyl hexyl phthalate was 0.5 and 1.13 for the HA and the sludge, respectively. By introducing the sludge to the solution of HA and TrOCs that already reached equilibrium, the sludge adsorption capacity in the presence of HA was investigated. The finding showed that at the lower concentration, adsorption of HA on the sludge was considered as the main removal pathway for the adsorbed emerging contaminants, as 70 mg of HA was adsorbed by a gram of sludge. For the higher concentration, desorption of TrOCs from DOM into the sludge comprised 15-30% of total removal efficiency. CBZ: carbamazepine; DEHP: di-2-ethyl hexyl phthalate; DOM: dissolved organic matter; FLAN: fluoranthene; f oc : fraction of organic carbon; HA: humic acid; Log Kow: octanol-water partition coefficient; PAH: polycyclic aromatic hydrocarbon TS: total solid; TrOCs: trace organic carbons VS: volatile solid.

Mesophilic and thermophilic anaerobic digestion of biologically pretreated abattoir wastewaters in an upflow anaerobic filter.

PubMed

Gannoun, H; Bouallagui, H; Okbi, A; Sayadi, S; Hamdi, M

2009-10-15

The hydrolysis pretreatment of abattoir wastewaters (AW), rich in organic suspended solids (fats and protein) was studied in static and stirred batch reactors without aeration in the presence of natural microbial population acclimated in a storage tank of AW. Microbial analysis showed that the major populations which contribute to the pretreatment of AW belong to the genera Bacillus. Contrary to the static pretreatment, the stirred conditions favoured the hydrolysis and solubilization of 80% of suspended matter into soluble pollution. The pretreated AW, in continuous stirred tank reactor (CSTR) at a hydraulic retention time (HRT) of 2 days, was fed to an upflow anaerobic filter (UAF) at an HRT of 2 days. The performance of anaerobic digestion of biologically pretreated AW was examined under mesophilic (37 degrees C) and thermophilic (55 degrees C) conditions. The shifting from a mesophilic to a thermophilic environment in the UAF was carried out with a short start-up of thermophilic condition. The UAF ran at organic loading rates (OLRs) ranging from 0.9 to 6g COD/Ld in mesophilic conditions and at OLRs from 0.9 to 9 g COD/Ld in thermophilic conditions. COD removal efficiencies of 80-90% were achieved for OLRs up to 4.5 g COD/Ld in mesophilic conditions, while the highest OLRs i.e. 9 g COD/Ld led to efficiencies of 70-72% in thermophilic conditions. The biogas yield in thermophilic conditions was about 0.32-0.45 L biogas/g of COD removed for OLRs up to 4.5 g COD/Ld. For similar OLR, the UAF in mesophilic conditions showed lower percentage of methanization. Mesophilic anaerobic digestion has been shown to destroy pathogens partially, whereas the thermophilic process was more efficient in the removal of indicator microorganisms and pathogenic bacteria at different organic loading rates.

Principal component analysis to assess the efficiency and mechanism for enhanced coagulation of natural algae-laden water using a novel dual coagulant system.

PubMed

Ou, Hua-Se; Wei, Chao-Hai; Deng, Yang; Gao, Nai-Yun; Ren, Yuan; Hu, Yun

2014-02-01

A novel dual coagulant system of polyaluminum chloride sulfate (PACS) and polydiallyldimethylammonium chloride (PDADMAC) was used to treat natural algae-laden water from Meiliang Gulf, Lake Taihu. PACS (Aln(OH)mCl3n-m-2k(SO4)k) has a mass ratio of 10 %, a SO4 (2-)/Al3 (+) mole ratio of 0.0664, and an OH/Al mole ratio of 2. The PDADMAC ([C8H16NCl]m) has a MW which ranges from 5 × 10(5) to 20 × 10(5) Da. The variations of contaminants in water samples during treatments were estimated in the form of principal component analysis (PCA) factor scores and conventional variables (turbidity, DOC, etc.). Parallel factor analysis determined four chromophoric dissolved organic matters (CDOM) components, and PCA identified four integrated principle factors. PCA factor 1 had significant correlations with chlorophyll-a (r=0.718), protein-like CDOM C1 (0.689), and C2 (0.756). Factor 2 correlated with UV254 (0.672), humic-like CDOM component C3 (0.716), and C4 (0.758). Factors 3 and 4 had correlations with NH3-N (0.748) and T-P (0.769), respectively. The variations of PCA factors scores revealed that PACS contributed less aluminum dissolution than PAC to obtain equivalent removal efficiency of contaminants. This might be due to the high cationic charge and pre-hydrolyzation of PACS. Compared with PACS coagulation (20 mg L(-1)), the removal of PCA factors 1, 2, and 4 increased 45, 33, and 12 %, respectively, in combined PACS-PDADMAC treatment (0.8 mg L(-1) +20 mg L(-1)). Since PAC contained more Al (0.053 g/1 g) than PACS (0.028 g/1 g), the results indicated that PACS contributed less Al dissolution into the water to obtain equivalent removal efficiency.

Value added phytoremediation of metal stressed soils using phosphate solubilizing microbial consortium.

PubMed

Gupta, Pratishtha; Kumar, Vipin

2017-01-01

The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.

Simulation of Constructed Wetland in treating Wastewater using Fuzzy Logic Technique

NASA Astrophysics Data System (ADS)

Sudarsan, J. S.; Subramani, Sheekha; Rajan, Rajitha J.; Shah, Isha; Nithiyanantham, S.

2018-04-01

Constructed wetlands act as a natural alternative to conventional methods of wastewater treatment. CW are found effective in wastewater containing inorganic matter, organic matter, toxic compounds, metals, nitrogen, phosphorous, heavy metals, organic chemicals, and pathogens. The treatment efficiency by the adaptation of CWs in treatment process is achieved by a complex interaction between plants, microorganisms, soil matrix and substances in the wastewater. Constructed wetland treatment systems are engineered systems designed in such a manner that it could take advantages of those processes occurring in natural wetlands in treating the wastewater concerned, but in a more controlled environment. Petrochemical wastewater was the type of wastewater taken for the study. Characteristics of petrochemical wastewater mainly oil, Biological Oxygen Demand (BOD) and Chemical oxygen demand (COD) were selected for treatment in constructed wetland as they are predominant in petrochemical wastewater. The conventional methods followed in the treatment are chemical and biological treatment. In this study, a fuzzy model for water quality assessment has been developed and water quality index value was obtained. The experiment conducted and further analysis using fuzzy logic indicated that interpretation of certain imprecise data can be improved within fuzzy inference system (FIS). Based on the analysis, we could observe that Typha sp contained wetland cell showed greater efficiency in removal of parameters such as COD and BOD than Phragmites sp. wetland cell.

Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.

PubMed

Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

2013-09-01

In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates. Copyright © 2013 Elsevier Ltd. All rights reserved.

Study on removal efficiency of nitrogen and phosphorus from agricultural wastewater by subsurface flow constructed wetland

NASA Astrophysics Data System (ADS)

Ling, Zhen; Li, Jie

2018-03-01

Subsurface Flow Constructed Wetland Plant 5 kinds of perennial herbs, there are Canna, Water onion, Iris, Calamus, Reed. Foucs on Subsurface Flow Constructed Wetlands on agricultural wastewater nitrogen and phosphorus removal effect. Research results: Different plants TP removal efficiency from high to low is Iris> reed> calamus> water onion> canna.And TN removal efficiency from high to low is reed> water onion> iris> calamus> canna. Compared with the blank test land, Wetland plants improves TN removal and TP removal is higher than TN. Wetland plants can reduce the PH of experimental water.

Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

PubMed

Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

2012-04-01

Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (p<0.05) enhancement in planted beds as compared to the unplanted beds. Removal of caffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of the multiple-ion competition in the adsorption of As(V) onto reclaimed iron-oxide coated sands by fractional factorial design.

PubMed

Hsu, Jia-Chin; Lin, Chien-Jung; Liao, Chih-Hsiang; Chen, Shyi-Tien

2008-07-01

This study describes the competitive effects of selected ions and natural organic matter on As(V) removal using reclaimed iron-oxide coated sands (RIOCS) in the single- and multi-ion systems. A 2(7-3) factional factorial experimental design (FFD) was employed for screening main competitive factors in this adsorption process. As a result, the inhibitive competition effects of the anions on As(V) removal in the single ion system were in the following sequence: PO(4)(3-)>SiO(3)(2-)>HCO(3)(-)>humic acid (HA)>SO(4)(2-)>Cl(-), whereas the cation Ca(2+) was observed to enhance the As(V) removal. In addition, the optimum initial pH for As(V) removal in single-ion system was 5. Based on the estimates of major effects and interactions from the FFD, PO(4)(3-), SiO(3)(2-), Ca(2+) and HA were important factors on As(V) removal in the multi-ion system. The promoters for the As(V) removal were found to be Ca(2+) and, to a lesser extent, SO(4)(2-). The competitive effects of these ions on As(V) removal were in the order of PO(4)(3-), SiO(3)(2-), HA, HCO(3)(-), and Cl(-). In the single ion system, the efficiencies of As(V) removal range from 75% to 96%, much higher than those in the multi-ion system (44%) at the initial pH 5. Clearly, there were some complex anion interactions in the multi-ion system. To promote the removal of As(V) by RIOCS, it is proposed to lower the pH in the single-ion system, while in the multi-ion system, the increase of the Ca(2+) concentration, or decreases of PO(4)(3-), SiO(3)(2-) and HA concentrations is suggested.

Enhancement of total nitrogen removal through effluent recirculation and fate of PPCPs in a hybrid constructed wetland system treating urban wastewater.

PubMed

Ávila, Cristina; Pelissari, Catiane; Sezerino, Pablo H; Sgroi, Massimiliano; Roccaro, Paolo; García, Joan

2017-04-15

The effect of effluent recirculation on the removal of total nitrogen (TN) and eight pharmaceuticals and personal care products (PPCPs) was evaluated during 9months in an experimental hybrid constructed wetland (CW) system applied in the treatment of urban wastewater. An Imhoff tank was followed by three stages of CWs (two 1.5-m 2 vertical subsurface flow (VF) beds alternating feed-rest cycles, a 2-m 2 horizontal (HF) and a 2-m 2 free water surface (FWS) wetland in series). A fraction of the final effluent was recycled back to the Imhoff tank with a recirculation rate of 50% (hydraulic loading rate=0.37md -1 ). The system's performance varied throughout the study. In Period I (summer) consistently high load removal efficiencies of TN (89±5%) and a removal rate of 6.6±1.4gTNm -2 d -1 were exhibited. In Period II (fall), the poor performance of the FWS during the senescence of macrophytes caused a large increase in organic matter, solids and nutrient concentrations, drastically deteriorating water quality. The determination of PPCPs was conducted during this period. Recalcitrant compounds, namely sulfamethoxazole, carbamazapine, TCEP and sucralose were negligibly removed in all CWs. However, noteworthy was the ≈30% removal of sucralose in the VF wetland. Caffeine (80%) and fluoxetine (27%) showed similar elimination rates in both VF and HF units, whereas trimethoprim and DEET were significantly better removed in the VF than in the HF. The concentration of the four latter compounds showed a severe increase in the FWS, indicating possible desorption from the sediment/biomass during adverse conditions. Harvesting of the aboveground biomass in this unit returned the system's performance back to normality (Period III), achieving 77±7% TN removal despite the winter season, proving effluent recirculation as an effective strategy for TN removal in hybrid CW systems when stringent restrictions are in place. Copyright © 2017 Elsevier B.V. All rights reserved.