These are representative sample records from related to your search topic.
For comprehensive and current results, perform a real-time search at

Textile wastewater treatment: aerobic granular sludge vs activated sludge systems.  


Textile effluents are characterised by high content of recalcitrant compounds and are often discharged (together with municipal wastewater to increase their treatability) into centralized wastewater treatment plants with a complex treatment scheme. This paper reports the results achieved adopting a granular sludge system (sequencing batch biofilter granular reactor - SBBGR) to treat mixed municipal-textile wastewater. Thanks to high average removals in SBBGR (82.1% chemical oxygen demand, 94.7% total suspended solids, 87.5% total Kjeldahl nitrogen, 77.1% surfactants), the Italian limits for discharge into a water receiver can be complied with the biological stage alone. The comparison with the performance of the centralized plant treating the same wastewater has showed that SBBGR system is able to produce an effluent of comparable quality with a simpler treatment scheme, a much lower hydraulic residence time (11 h against 30 h) and a lower sludge production. PMID:24583525

Lotito, Adriana Maria; De Sanctis, Marco; Di Iaconi, Claudio; Bergna, Giovanni



40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.  

Code of Federal Regulations, 2013 CFR

...false Slimes and sludges, aluminum and iron casting, wastewater treatment, solid...10667 Slimes and sludges, aluminum and iron casting, wastewater treatment, solid...generically as slimes and sludges, aluminum and iron casting, wastewater treatment,...



40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.  

...false Slimes and sludges, aluminum and iron casting, wastewater treatment, solid...10667 Slimes and sludges, aluminum and iron casting, wastewater treatment, solid...generically as slimes and sludges, aluminum and iron casting, wastewater treatment,...



Microwave Irradiation Technology In Waste Sludge And Wastewater Treatment Research  

Microsoft Academic Search

In pursuit of a green and sustainable world, wastewater remediation and sludge treatment have equally become a growing global environmental concern. Several innovative treatment processes have been designed throughout the last few decades for treating wastewaters and sludges but many of them are very costly and operate at low efficiencies. In view to find novel treatment processes, active research is

Ackmez Mudhoo; Sanjay Kumar Sharma



Dry stacking of wastewater treatment sludges.  


Drying pans are used during wastewater treatment (WWT) to store, stabilise and dry residual solids. The pans are filled with sludge that dries via exposure to sunshine and wind. We propose that drying pans be operated based on dry stacking principles, a technique with proven success in the mineral processing industry. The implementation of the dry stacking technique requires very little in the way of additional engineering beyond a conventional drying pan. By applying the sludge in thin layers, the sludge naturally forms its own stack with an angle that is dependent on the consistency of the material. The benefits of dry stacking are that the slope allows instantaneous run-off of rainfall and supernatant, allowing operation throughout the year rather than seasonally. The layering approach also maximises the evaporation achieved in the available deposition area compared to filling the pans sequentially. A series of laboratory tests were carried out on samples from Melbourne Water's Western Treatment Plant in Werribee, Australia, to provide validation of the dry stacking concept for WWT sludges. Rheological tests showed that samples had appropriate flow properties to form stacks. Drying and re-wetting tests on the samples indicated that a sloped, partially dry sludge sheds rainfall, depending on the slope, cake dryness and amount of rainfall. Local rainfall data was used to estimate a potential increase in pan throughput of 65%-140% due to dry stacking. The greatest improvements were predicted to occur during wetter years. In combination, the results indicated that dry stacking has the potential to dramatically improve the performance of WWT sludge drying pans. PMID:23642401

Stickland, Anthony D; Rees, Catherine A; Mosse, Kim P M; Dixon, David R; Scales, Peter J



Digital image processing and analysis for activated sludge wastewater treatment.  


Activated sludge system is generally used in wastewater treatment plants for processing domestic influent. Conventionally the activated sludge wastewater treatment is monitored by measuring physico-chemical parameters like total suspended solids (TSSol), sludge volume index (SVI) and chemical oxygen demand (COD) etc. For the measurement, tests are conducted in the laboratory, which take many hours to give the final measurement. Digital image processing and analysis offers a better alternative not only to monitor and characterize the current state of activated sludge but also to predict the future state. The characterization by image processing and analysis is done by correlating the time evolution of parameters extracted by image analysis of floc and filaments with the physico-chemical parameters. This chapter briefly reviews the activated sludge wastewater treatment; and, procedures of image acquisition, preprocessing, segmentation and analysis in the specific context of activated sludge wastewater treatment. In the latter part additional procedures like z-stacking, image stitching are introduced for wastewater image preprocessing, which are not previously used in the context of activated sludge. Different preprocessing and segmentation techniques are proposed, along with the survey of imaging procedures reported in the literature. Finally the image analysis based morphological parameters and correlation of the parameters with regard to monitoring and prediction of activated sludge are discussed. Hence it is observed that image analysis can play a very useful role in the monitoring of activated sludge wastewater treatment plants. PMID:25381111

Khan, Muhammad Burhan; Lee, Xue Yong; Nisar, Humaira; Ng, Choon Aun; Yeap, Kim Ho; Malik, Aamir Saeed



Sludge reduction by lumbriculus variegatus in Ahvas wastewater treatment plant  

PubMed Central

Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. Application of aquatic worm is an approach to decrease the amount of biological waste sludge produced in wastewater treatment plants. In the present research reduction of the amount of waste sludge from Ahvaz wastewater treatment plant was studied with the aquatic worm Lumbriculus variegatus in a reactor concept. The sludge reduction in the reactor with worm was compared to sludge reduction in a blank reactor (without worm). The effects of changes in dissolved oxygen (DO) concentration up to 3 mg/L (run 1) and up to 6 mg/L (run 2) were studied in the worm and blank reactors. No meaningful relationship was found between DO concentration and the rate of total suspended solids reduction. The average sludge reductions were obtained as 32% (run 1) and 33% (run 2) in worm reactor and 16% (run 1) and 12% (run 2) in the blank reactor. These results showed that the worm reactors may reduce the waste sludge between 2 and 2.75 times higher than in the blank conditions. The obtained results showed that the worm reactor has a high potential for use in large-scale sludge processing. PMID:23369451



Polyhydroxyalkanoate (PHA) production from sludge and municipal wastewater treatment.  


Polyhydroxyalkanoates (PHAs) are biodegradable polyesters with comparable properties to some petroleum-based polyolefins. PHA production can be achieved in open, mixed microbial cultures and thereby coupled to wastewater and solid residual treatment. In this context, waste organic matter is utilised as a carbon source in activated sludge biological treatment for biopolymer synthesis. Within the EU project Routes, the feasibility of PHA production has been evaluated in processes for sludge treatment and volatile fatty acid (VFA) production and municipal wastewater treatment. This PHA production process is being investigated in four units: (i) wastewater treatment with enrichment and production of a functional biomass sustaining PHA storage capacity, (ii) acidogenic fermentation of sludge for VFA production, (iii) PHA accumulation from VFA-rich streams, and (iv) PHA recovery and characterisation. Laboratory- and pilot-scale studies demonstrated the feasibility of municipal wastewater and solid waste treatment alongside production of PHA-rich biomass. The PHA storage capacity of biomass selected under feast-famine with municipal wastewater has been increased up to 34% (g PHA g VSS(-1)) in batch accumulations with acetate during 20 h. VFAs obtained from waste activated sludge fermentation were found to be a suitable feedstock for PHA production. PMID:24434985

Morgan-Sagastume, F; Valentino, F; Hjort, M; Cirne, D; Karabegovic, L; Gerardin, F; Johansson, P; Karlsson, A; Magnusson, P; Alexandersson, T; Bengtsson, S; Majone, M; Werker, A



Disinfection of sewage wastewater and sludge by electron treatment  

NASA Astrophysics Data System (ADS)

The use of machine-accelerated electrons to disinfect sewage waterwaste and sludge is discussed. The method is shown to be practical and energy-efficient for the broad spectrum disinfection of pathogenic organisms in municipal wastewaters and sludge removed from them. Studies of biological, chemical and physical effects are reported. Electron treatment is suggested as an alternative to chlorination of municipal liquid wastes after electron treatment to provide disinfection. Disposal of sewage sludge is recommended as an agricultural resource by subsurface land injection, or as a nutrient for fish populations by widespread ocean dispersal.

Trump, J. G.; Merrill, E. W.; Wright, K. A.



EPA Science Inventory

Data for estimating average construction costs and operation and maintenance requirements are presented for thermal treatment of municipal wastewater sludges; for handling, treatment, and disposal of the strong liquor generated; and for controlling odors produced. Size ranges cov...


Impact of secondary treatment types and sludge handling processes on estrogen concentration in wastewater sludge.  


Endocrine-disrupting compounds (EDCs), such as estrogen, are known to be present in the aquatic environment at concentrations that negatively affect fish and other wildlife. Wastewater treatment plants (WWTPs) are major contributors of EDCs into the environment. EDCs are released via effluent discharge and land application of biosolids. Estrogen removal in WWTPs has been studied in the aqueous phase; however, few researchers have determined estrogen concentration in sludge. This study focuses on estrogen concentration in wastewater sludge as a result of secondary treatment types and sludge handling processes. Grab samples were collected before and after multiple treatment steps at two WWTPs receiving wastewater from the same city. The samples were centrifuged into aqueous and solid phases and then processed using solid phase extraction. Combined natural estrogens (estrone, estradiol and estriol) were measured using an enzyme-linked immunosorbent assay (ELISA) purchased from a manufacturer. Results confirmed that activated sludge treatments demonstrate greater estrogen removal compared to trickling filters and mass concentration of estrogen was measured for the first time on trickling filter solids. Physical and mechanical sludge treatment processes, such as gravity thickeners and centrifuges, did not significantly affect estrogen removal based on mass balance calculations. Dissolved air flotation thickening demonstrated a slight decrease in estrogen concentration, while anaerobic digestion resulted in increased mass concentration of estrogen on the sludge and a high estrogen concentration in the supernatant. Although there are no state or federally mandated discharge effluent standards or sludge application standards for estrogen, implications from this study are that trickling filters would need to be exchanged for activated sludge treatment or followed by an aeration basin in order to improve estrogen removal. Also, anaerobic digestion may need to be replaced with aerobic digestion for sludge that is intended for land application. PMID:24239827

Marti, Erica J; Batista, Jacimaria R



Cultivation of aerobic granular sludge for rubber wastewater treatment.  


Aerobic granular sludge (AGS) was successfully cultivated at 27±1 °C and pH 7.0±1 during the treatment of rubber wastewater using a sequential batch reactor system mode with complete cycle time of 3 h. Results showed aerobic granular sludge had an excellent settling ability and exhibited exceptional performance in the organics and nutrients removal from rubber wastewater. Regular, dense and fast settling granule (average diameter, 1.5 mm; settling velocity, 33 m h(-1); and sludge volume index, 22.3 mL g(-1)) were developed in a single reactor. In addition, 96.5% COD removal efficiency was observed in the system at the end of the granulation period, while its ammonia and total nitrogen removal efficiencies were up to 94.7% and 89.4%, respectively. The study demonstrated the capabilities of AGS development in a single, high and slender column type-bioreactor for the treatment of rubber wastewater. PMID:23317554

Rosman, Noor Hasyimah; Nor Anuar, Aznah; Othman, Inawati; Harun, Hasnida; Sulong Abdul Razak, Muhammad Zuhdi; Elias, Siti Hanna; Mat Hassan, Mohd Arif Hakimi; Chelliapan, Shreesivadass; Ujang, Zaini



The use of waterworks sludge for the treatment of vegetable oil refinery industry wastewater  

Microsoft Academic Search

Water treatment works using coagulation\\/flocculation in the process stream will generate a waste sludge. This sludge is termed as ferric, alum, or lime sludge based on which coagulant was primarily used. The works in Adana, Turkey uses ferric chloride. The potential for using this sludge for the treatment of vegetable oil refinery industry wastewater by coagulation has been investigated. The

M. Basibuyuk; D. G. Kalat



Development of anaerobic sludge bed (ASB) reactor technologies for domestic wastewater treatment: motives and perspectives  

Microsoft Academic Search

During the treatment of raw domestic wastewater in the upflow anaerobic sludge blanket (UASB) reactor, the suspended solids (SS) present in the wastewater tend to influence negatively the methanogenic activity and the chemical oxygen demand (COD) conversion efficiency. These problems led to the emergence of various anaerobic sludge bed systems such as the expanded granular sludge bed (EGSB), the upflow

Youssouf Kalogo; Willy Verstraete



Sludge minimization in municipal wastewater treatment by polyhydroxyalkanoate (PHA) production.  


An innovative approach has been recently proposed in order to link polyhydroxyalkanoates (PHA) production with sludge minimization in municipal wastewater treatment, where (1) a sequencing batch reactor (SBR) is used for the simultaneous municipal wastewater treatment and the selection/enrichment of biomass with storage ability and (2) the acidogenic fermentation of the primary sludge is used to produce a stream rich in volatile fatty acids (VFAs) as the carbon source for the following PHA accumulation stage. The reliability of the proposed process has been evaluated at lab scale by using substrate synthetic mixtures for both stages, simulating a low-strength municipal wastewater and the effluent from primary sludge fermentation, respectively. Six SBR runs were performed under the same operating conditions, each time starting from a new activated sludge inoculum. In every SBR run, despite the low VFA content (10?% chemical oxygen demand, COD basis) of the substrate synthetic mixture, a stable feast-famine regime was established, ensuring the necessary selection/enrichment of the sludge and soluble COD removal to 89 %. A good process reproducibility was observed, as also confirmed by denaturing gradient gel electrophoresis (DGGE) analysis of the microbial community, which showed that a high similarity after SBR steady-state had been reached. The main variation factors of the storage properties among different runs were uncontrolled changes of settling properties which in turn caused variations of both sludge retention time and specific organic loading rate. In the following accumulation batch tests, the selected/enriched consortium was able to accumulate PHA with good rate (63 mg CODPHA g CODXa (-1)?h(-1)) and yield (0.23 CODPHA COD?S (-1)) in spite that the feeding solution was different from the acclimation one. Even though the PHA production performance still requires optimization, the proposed process has a good potential especially if coupled to minimization of both primary sludge (by its use as the VFA source for the PHA accumulation, via previous fermentation) and excess secondary sludge (by its use as the biomass source for the PHA accumulation). PMID:24996948

Valentino, Francesco; Morgan-Sagastume, Fernando; Fraraccio, Serena; Corsi, Giovanna; Zanaroli, Giulio; Werker, Alan; Majone, Mauro



Technology for recovering phosphorus from incinerated wastewater treatment sludge.  


A bench-top study of phosphorus-recovering technology from ash associated with incinerated wastewater (sewage) treatment sludge was conducted by adding sulfuric acid to ashes for the elution of phosphorus. With the exception of lead, which is insoluble in sulfuric acid, when the pH of the ash fell below 2.0, phosphorus and various heavy metals in the ash were extracted. The study found that, when alkalis were added to adjust the pH of the ash extract to 4.0, phosphorus was subsequently recovered via filtration. Furthermore, when alkalis were added to adjust the pH to 10, the recovery of various heavy metals was observed. In addition, disposal of the remaining solution (wastewater), which consists of a relatively low concentration of salts, is not considered to be a significant issue since it is within wastewater discharge standards and has been found to be useful as an acid-treating substance. PMID:11419755

Takahashi, M; Kato, S; Shima, H; Sarai, E; Ichioka, T; Hatyakawa, S; Miyajiri, H



Pilot Scale Study of Excess Sludge Production Reduction in Wastewater Treatment by Ozone  

E-print Network

Pilot Scale Study of Excess Sludge Production Reduction in Wastewater Treatment by Ozone Yuan Ma-scale reactors were operated at the LaPrairie Wastewater Treatment plant (one control and one ozonated, Dominic Frigon Department of Civil EngineeringINTRODUCTION Activated sludge treatment processes produce

Barthelat, Francois



EPA Science Inventory

A computer-aided design procedure for the preliminary synthesis of wastewater treatment and sludge disposal systems is developed. It selects the components in the wastewater treatment and sludge disposal trains from a list of candidate process units with fixed design characterist...


Energy use and recovery strategies within wastewater treatment and sludge handling at pulp and paper mills.  


This paper presents an inclusive approach with focus on energy use and recovery in wastewater management, including wastewater treatment (WWT) and sludge handling. Process data from three Swedish mills and a mathematical model were used to evaluate seven sludge handling strategies. The results indicate that excess energy use in WWT processes counters the potential energy recovery in the sludge handling systems. Energy use in WWT processes is recommended to aim for sufficient effluent treatment, not for sludge reduction. Increased secondary sludge production is favourable from an energy point of view provided it is used as a substrate for heat, biogas or electricity production. PMID:19307113

Stoica, Alina; Sandberg, Maria; Holby, Ola




EPA Science Inventory

The seminar publication provides practical information on current methods of composting municipal wastewater sludges. It is intended for government and private sector individuals involved in the planning, design, and operation of municipal sludge treatment and disposal systems. C...


Application of vibration milling for advanced wastewater treatment and excess sludge reduction.  


As a new sludge reduction technology with a phosphorus removal mechanism, a vibration milling technology that uses iron balls have been applied to the wastewater treatment process. Three anaerobic-aerobic cyclic activated sludge processes: one without sludge disintegration; one disintegrated sludge by ozonation; and the other disintegrated sludge with the vibrating ball mill were compared. Ozonation achieved the best sludge reduction performance, but milling had the best phosphorus removal. This is because iron was mixed into the wastewater treatment tank due to abrasion of the iron balls, leading to settling of iron phosphates. Thus, the simple means of using iron balls as the medium in a vibrating ball mill can achieve both a sludge reduction of half and excellent phosphorus removal. Material balances in the processes were calculated and it was found that carbon components in disintegrated sludge were more resistant to biological treatment than nitrogen. PMID:22173418

Sano, Akira; Senga, Akira; Yamazaki, Hiroshi; Inoue, Hiroki; Xu, Kai-Qin; Inamori, Yuhei



Electro-coagulation treatment of oily wastewater with sludge analysis.  


Experiments were carried out in a batch reactor to treat the oily effluent by electro-coagulation. The influence of operating parameters such as applied current, type of electrode and electrolysis time on electro-coagulation efficiency has been critically examined. The maximum percentage removal of chemical oxygen demand (COD) was 94% under optimum experimental conditions of pH 6.7, current density 6 mA/cm², electrolysis time 40 min, and using mild steel as anode. The remaining sludge in the reactor was analyzed by energy disperse analysis of X-rays (EDAX) and scanning electron microscope (SEM) analysis. The analysis confirms that the oily pollutant was removed by electroflotation and adsorption of the oily particles of precipitate during the electro-coagulation process. Electro-coagulation can be used as an efficient treatment technique for oily wastewater. PMID:23109567

Ibrahim, Dhorgham Skban; Sakthipriya, N; Balasubramanian, N



Bacterial Diversity of Active Sludge in Wastewater Treatment Plant  

NASA Astrophysics Data System (ADS)

A bacterial 16S rDNA gene clone library was constructed to analyze the bacterial diversity of active sludge in Gaobeidian Wastewater Treatment Plant, Beijing. The results indicated that the bacterial diversity of active sludge was very high, and the clones could be divided into 5 different groups. The dominant bacterial community was proteobacteria, which accounted for 76.7%. The dominant succession of bacterial community were as follows: the ?-proteobacteria (39.8%), the uncultured bacteria (22.33%), the ?-proteobacteria (20.15%), the ?-proteobacteria (6.79%), and the ?-proteobacteria (4.85%). Nitrosomonas-like and Nitrospira-like bacteria, such as Nitrosomonas sp. (1.94%) and uncultured Nitrospirae bacterium (11.65%) were also detected, which have played important roles in ammonia and nitrite oxidisers in the system. However, they were only a little amount because of their slow growth and less competitive advantage than heterotrophic bacteria. Denitrifying bacteria like Thauera sp. was at a high percentage, which implies a strong denitrification ability; Roseomonas sp. was also detected in the clone library, which could be related to the degradation of organophosphorus pesticide.

Jiang, Xin; Ma, Mingchao; Li, Jun; Lu, Anhuai; Zhong, Zuoshen



EPA Science Inventory

This report presents the results of field measurements and observations of a land treatment site for the management of secondary wastewater treatment sludge from a synthetics manufacturing plant. The waste, composed of 8.5% solids, contained a large concentration of cellulose and...


Evaluation of thickening and dewatering characteristics of SRC-I wastewater treatment sludges. Final technical report  

SciTech Connect

The SRC-I Demonstration Plant in Newman, Kentucky, will generate several different sludges as a result of providing extensive wastewater treatment. Because construction of this plant has been postponed indefinitely, there has been an opportunity to generate additional data pertinent to waste treatment. Accordingly, this report presents the results of a study on the thickening and dewatering characteristics of several of the wastewater treatment sludges. The study included: evaluation of chemical conditioning agents; aerobic digestion of biological sludges; gravity thickening; and the relative effectiveness of dewatering by centrifuge, vacuum filter, belt filter, and pressure filter. Sludges were tested individually and in combination. The results indicated that the biological sludge could be best dewatered by pressure filtration. The chemical sludges should be combined prior to dewatering, which should be provided by a belt filter. The tar acid sludge will be kept separate, due to its low pH, and ultimate disposal will be by incineration. The tar acid sludge was more concentrated than had been expected. As a result, thickening, rather than centrifuging, is the recommended treatment for this sludge. All sludges were tested for leachate toxicity by the extraction procedure method. The results were negative, indicating the sludges are non-hazardous in heavy metal concentrations, according to RCRA classification. The test results have identified design changes for the proposed wastewater treatment facilities.

Not Available




EPA Science Inventory

Personnel employed at wastewater treatment plant sludge composting operations are exposed to a variety of viable gram-negative bacteria, and fungi as well as microbial products such as endotoxin (lipopolysaccharide (LPS)) in their work environment. This investigation was designed...



EPA Science Inventory

Research emphasis by the United States Environmental Protection Agency in wastewater treatment has focussed on control of toxics and sludge management. The paper describes highlights of the Environmental Protection Agency's research in these areas. The research on toxics control ...


Community Composition of Known and Uncultured Archaeal Lineages in Anaerobic or Anoxic Wastewater Treatment Sludge.  


Microbial systems are widely used to treat different types of wastewater from domestic, agricultural, and industrial sources. Community composition is an important factor in determining the successful performance of microbial treatment systems; however, a variety of uncultured and unknown lineages exist in sludge that requires identification and characterization. The present study examined the archaeal community composition in methanogenic, denitrifying, and nitrogen-/phosphate-removing wastewater treatment sludge by Archaea-specific 16S rRNA gene sequencing analysis using Illumina sequencing technology. Phylotypes belonging to Euryarchaeota, including methanogens, were most abundant in all samples except for nitrogen-/phosphate-removing wastewater treatment sludge. High levels of Deep Sea Hydrothermal Vent Group 6 (DHVEG-6), WSA2, Terrestrial Miscellaneous Euryarchaeotal Group, and Miscellaneous Crenarchaeotic Group were also detected. Interestingly, DHVEG-6 was dominant in nitrogen-/phosphate-removing wastewater treatment sludge, indicating that unclear lineages of Archaea still exist in the anaerobic wastewater treatment sludges. These results reveal a previously unknown diversity of Archaea in sludge that can potentially be exploited for the development of more efficient wastewater treatment strategies. PMID:25373332

Kuroda, Kyohei; Hatamoto, Masashi; Nakahara, Nozomi; Abe, Kenichi; Takahashi, Masanobu; Araki, Nobuo; Yamaguchi, Takashi



Municipal wastewater treatment by periodic biofilter without excess sludge production.  


The paper reports the results of an investigation aimed at evaluating the performances of a periodic biofilter (SBBR) for treating municipal wastewater. The investigation was carried out at laboratory scale on real primary effluent coming from a municipal wastewater treatment plant located in Southern Italy. The SBBR was designed for carbon and nitrogen removal through one single stage. The results have shown that even at maximum organic load (i.e., 7 kg COD/m3.d), the COD in the effluent was lower than 60 mg/L. TKN removal efficiencies resulted high (i.e. 90-95%) up to an organic load of 5.7 kg COD/m3.d corresponding to a nitrogen load of 0.8 kg TKN/m3.d. NO3-N concentration in the treated effluent was lesser than 6 mg/L although in the SBBR treatment cycle no anoxic phase was scheduled. This indicated that denitrification extensively took place in the biofilter. The process was characterized by high suspended solids removal (about 90%) and by a negligible sludge production (lower than 0.01 kgVSS/kgCODremoved). In the SBBR, biomass grew as granules and was characterised by different measurements (biomass concentration, cellular protein and biomass density). Biomass density resulted very high, i.e. 200 gTSS/Lbiomass, and this permitted to achieve a biomass concentration such high as 40 gTSS/Lbed. Such biomass concentration did not cause any decrease of biomass metabolic activity as proved by its total protein content (29% of organic matter) and maximum oxygen uptake rate value (i.e. 50 mgO2/gVSS h). PMID:16136839

Di Iaconi, Claudio; Ramadori, Roberto; Lopez, Antonio; Passino, Roberto



Operating aerobic wastewater treatment at very short sludge ages enables treatment and energy recovery through anaerobic sludge digestion.  


Conventional abattoir wastewater treatment processes for carbon and nutrient removal are typically designed and operated with a long sludge retention time (SRT) of 10-20 days, with a relatively high energy demand and physical footprint. The process also generates a considerable amount of waste activated sludge that is not easily degradable due to the long SRT. In this study, an innovative high-rate sequencing batch reactor (SBR) based wastewater treatment process with short SRT and hydraulic retention time (HRT) is developed and characterised. The high-rate SBR process was shown to be most effective with SRT of 2-3 days and HRT of 0.5-1 day, achieving >80% reduction in chemical oxygen demand (COD) and phosphorus and approximately 55% nitrogen removal. A majority of carbon removal (70-80%) was achieved by biomass assimilation and/or accumulation, rather than oxidation. Anaerobic degradability of the sludge generated in the high-rate SBR process was strongly linked to SRT, with measured degradability extent being 85% (2 days SRT), 73% (3 days), and 63% (4 days), but it was not influenced by digestion temperature. However, the rate of degradation for 3 and 4 days SRT sludge was increased by 45% at thermophilic conditions compared to mesophilic conditions. Overall, the treatment process provides a very compact and energy efficient treatment option for highly degradable wastewaters such as meat and food processing, with a substantial space reduction by using smaller reactors and a considerable net energy output through the reduced aerobic oxidation and concurrent increased methane production potential through the efficient sludge digestion. PMID:24045213

Ge, Huoqing; Batstone, Damien J; Keller, Jurg



Pre-treatment of wastewater sludge--biodegradability and rheology study.  


This study investigates the changes in biodegradability, rheology and metal concentration of wastewater sludge--non-hydrolyzed (raw), sterilized, and hydrolyzed (thermal alkaline pre-treatment) at total solids concentration from 10-50 g l(-1) to ascertain the bioavailability of nutrients for subsequent fermentation. The dissolved solids concentration increased linearly with total solids. Irrespective of the wastewater sludge (raw or, pre-treated), percentage biodegradability in terms of total solids (26.5-44.5%), total COD (25.8-56.5%) and dissolved solids (41.9-66.9%) was maximum around 20 g l(-1) solids concentration. The pseudoplasticity of sludge decreased (consistency index decreased from 895.1 to 5.2 and flow behaviour index increased from 0.28 to 0.88, for all sludge types) with pre-treatment and increased with total solids concentration. The pre-treated sludge, namely, sterilized and hydrolyzed sludge showed higher microbial growth (1-2 log cycles increase in comparison to raw sludge) suggesting their susceptibility to microbial degradation. The C:N ratio decreased with pre-treatment (raw sludge > sterilized > hydrolyzed) during biodegradation. Although the metal concentration increased in incubated hydrolyzed sludge, the final concentration was within the regulatory norms for agriculture application. Thus, pretreatment of sludge resulted in increase in biodegradability making it an excellent proponent for fermented value-added products. PMID:17432380

Verma, M; Brar, Satinder K; Riopel, A R; Tyagi, R D; Surampalli, R Y



A Guide for Developing Standard Operating Job Procedures for the Sludge Conditioning & Dewatering Process Wastewater Treatment Facility. SOJP No. 11.  

ERIC Educational Resources Information Center

This guide describes standard operating job procedures for the sludge conditioning and dewatering process of wastewater treatment facilities. In this process, sludge is treated with chemicals to make the sludge coagulate and give up its water more easily. The treated sludge is then dewatered using a vacuum filter. The guide gives step-by-step…

Schwing, Carl M.


Characterization, Modeling and Application of Aerobic Granular Sludge for Wastewater Treatment  

NASA Astrophysics Data System (ADS)

Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve.

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping


Characterization, modeling and application of aerobic granular sludge for wastewater treatment.  


Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve. PMID:19373449

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping



Thermal sludge dryer demonstration: Bird Island Wastewater Treatment Plant, Buffalo, NY. Final report  

SciTech Connect

The Buffalo Sewer Authority (BSA), in cooperation with the New York State Energy Research and Development Authority (Energy Authority), commissioned a demonstration of a full scale indirect disk-type sludge dryer at the Bird Island Wastewater Treatment Plant (BIWWTP). The purpose of the project was to determine the effects of the sludge dryer on the sludge incineration process at the facility. Sludge incineration is traditionally the most expensive, energy-intensive unit process involving solids handling at wastewater treatment plants; costs for incineration at the BIWWTP have averaged $2.4 million per year. In the conventional method of processing solids, a series of volume reduction measures, which usually includes thickening, digestion, and mechanical dewatering, is employed prior to incineration. Usually, a high level of moisture is still present within sewage sludge following mechanical dewatering. The sludge dryer system thermally dewaters wastewater sludge to approximately 26%, (and as high as 38%) dry solids content prior to incineration. The thermal dewatering system at the BIWWTP has demonstrated that it meets its design requirements. It has the potential to provide significant energy and other cost savings by allowing the BSA to change from an operation employing two incinerators to a single incinerator mode. While the long-term reliability of the thermal dewatering system has yet to be established, this project has demonstrated that installation of such a system in an existing treatment plant can provide the owner with significant operating cost savings.




Examination of the operator and compensator tank role in urban wastewater treatment using activated sludge method.  


No doubt, operator is one of the main fundaments in wastewater treatment plants. By identifying the inadequacies, the operator could be considered as an important key in treatment plant. Several methods are used for wastewater treatment that requires spending a lot of cost. However, all investments of treatment facilities are usable when the expected efficiency of the treatment plant was obtained. Using experienced operator, this goal is more easily accessible. In this research, the wastewater of an urban community contaminated with moderated, diluted and highly concentrated pollution has been treated using surface and deep aeration treatment method. Sampling of these pilots was performed during winter 2008 to summer 2009. The results indicate that all analyzed parameters were eliminated using activated sludge and surface aeration methods. However, in activated sludge and deep aeration methods in combination with suitable function of operator, more pollutants could be eliminated. Hence, existence of operator in wastewater treatment plants is the basic principle to achieve considered efficiency. Wastewater treatment system is not intelligent itself and that is the operator who can organize even an inefficient system by its continuous presence. The converse of this fact is also real. Despite the various units and appropriate design of wastewater treatment plant, without an operator, the studied process cannot be expected highly efficient. In places frequently affected by the shock of organic and hydraulic loads, the compensator tank is important to offset the wastewater treatment process. Finally, in regard to microbial parameters, existence of disinfection unit is very useful. PMID:20571882

Mokhtari Azar, Akbar; Ghadirpour Jelogir, Ali; Nabi Bidhendi, Gholam Reza; Zaredar, Narges



Diversity and dynamics of Archaea in an activated sludge wastewater treatment plant  

PubMed Central

Background The activated sludge process is one of the most widely used methods for treatment of wastewater and the microbial community composition in the sludge is important for the process operation. While the bacterial communities have been characterized in various activated sludge systems little is known about archaeal communities in activated sludge. The diversity and dynamics of the Archaea community in a full-scale activated sludge wastewater treatment plant were investigated by fluorescence in situ hybridization, terminal restriction fragment length polymorphism analysis and cloning and sequencing of 16S rRNA genes. Results The Archaea community was dominated by Methanosaeta-like species. During a 15?month period major changes in the community composition were only observed twice despite seasonal variations in environmental and operating conditions. Water temperature appeared to be the process parameter that affected the community composition the most. Several terminal restriction fragments also showed strong correlations with sludge properties and effluent water properties. The Archaea were estimated to make up 1.6% of total cell numbers in the activated sludge and were present both as single cells and colonies of varying sizes. Conclusions The results presented here show that Archaea can constitute a constant and integral part of the activated sludge and that it can therefore be useful to include Archaea in future studies of microbial communities in activated sludge. PMID:22784022




EPA Science Inventory

The authors describe their experience with the isolation of viruses from four treatment plants located in different geographic areas. Over a period of 3 years, 297 enteroviruses were isolated from 307 sludge samples. The highest frequency of viral isolation (92%), including multi...


Changes in hormone and stress-inducing activities of municipal wastewater in a conventional activated sludge wastewater treatment plant.  


Conventional municipal wastewater treatment plants do not efficiently remove contaminants of emerging concern, and so are primary sources for contaminant release into the aquatic environment. Although these contaminants are present in effluents at ng-?g/L concentrations (i.e. microcontaminants), many compounds can act as endocrine disrupting compounds or stress-inducing agents at these levels. Chemical fate analyses indicate that additional levels of wastewater treatment reduce but do not always completely remove all microcontaminants. The removal of microcontaminants from wastewater does not necessarily correspond to a reduction in biological activity, as contaminant metabolites or byproducts may still be biologically active. To evaluate the efficacy of conventional municipal wastewater treatment plants to remove biological activity, we examined the performance of a full scale conventional activated sludge municipal wastewater treatment plant located in Guelph, Ontario, Canada. We assessed reductions in levels of conventional wastewater parameters and thyroid hormone disrupting and stress-inducing activities in wastewater at three phases along the treatment train using a C-fin assay. Wastewater treatment was effective at reducing total suspended solids, chemical and biochemical oxygen demand, and stress-inducing bioactivity. However, only minimal reduction was observed in thyroid hormone disrupting activities. The present study underscores the importance of examining multiple chemical and biological endpoints in evaluating and monitoring the effectiveness of wastewater treatment for removal of microcontaminants. PMID:25222330

Wojnarowicz, Pola; Yang, Wenbo; Zhou, Hongde; Parker, Wayne J; Helbing, Caren C



Aeration control in a full-scale activated sludge wastewater treatment plant: impact on performances, energy consumption  

E-print Network

Aeration control in a full-scale activated sludge wastewater treatment plant: impact strategy on energy consumption and nitrous oxide (N2O) emission in a full-scale wastewater treatment plant for stratospheric ozone [1]. In biological wastewater treatment, microbial processes such as hydroxylamine oxidation

Paris-Sud XI, Université de


Bioavailable and biodegradable dissolved organic nitrogen in activated sludge and trickling filter wastewater treatment plants  

Technology Transfer Automated Retrieval System (TEKTRAN)

A study was carried out to understand the fate of biodegradable dissolved organic nitrogen (BDON) and bioavailable dissolved organic nitrogen (ABDON) along the treatment trains of a wastewater treatment facility (WWTF) equipped with an activated sludge (AS) system and a WWTF equipped with a two-stag...


Rheology Measurements for Online Monitoring of Solids in Activated Sludge Reactors of Municipal Wastewater Treatment Plant  

PubMed Central

Rheological behaviour of recycled sludge from a secondary clarifier of a municipal wastewater treatment plant was studied by using the rate controlled coaxial cylinder viscometer Rotovisko-Haake 20, system M5-osc., measuring device NV. The tests (hysteresis cycles) were performed under continuous flow conditions and following an ad hoc measurement protocol. Sludge shear stress versus shear rate curves were fitted very satisfactorily by rheological models. An experimental equation correlating the solid concentration of sludge to relative viscosity and fitting satisfactorily flow curves at different Total Suspended Solids (TTS%) was obtained. Application of the empirical correlation should allow the monitoring of the proper functioning of a wastewater treatment plant measuring viscosity of sludge. PMID:24550715

Papo, Adriano; Goi, Daniele



A comprehensive substance flow analysis of a municipal wastewater and sludge treatment plant.  


The fate of total organic carbon, 32 elements (Al, Ag, As, Ba, Be, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, N, Na, Ni, P, Pb, S, Sb, Se, Sn, Sr, Ti, V, and Zn) and 4 groups of organic pollutants (linear alkylbenzene sulfonates, bis(2-ethylhexyl)phthalate, polychlorinated biphenyl and polycyclic aromatic hydrocarbons) in a conventional wastewater treatment plant were assessed. Mass balances showed reasonable closures for most of the elements. However, gaseous emissions were accompanied by large uncertainties and show the limitation of mass balance based substance flow analysis. Based on the assessment, it is evident that both inorganic and organic elements accumulated in the sewage sludge, with the exception of elements that are highly soluble or degradable by wastewater and sludge treatment processes. The majority of metals and metalloids were further accumulated in the incineration ash, while the organic pollutants were effectively destroyed by both biological and thermal processes. Side streams from the sludge treatment process (dewatering and incineration) back to the wastewater treatment represented less than 1% of the total volume entering the wastewater treatment processes, but represented significant substance flows. In contrast, the contribution by spent water from the flue gas treatment process was almost negligible. Screening of human and eco-toxicity by applying the consensus-based environmental impact assessment method USEtox addressing 15 inorganic constituents showed that removal of inorganic constituents by the wastewater treatment plant reduced the toxic impact potential by 87-92%. PMID:24231042

Yoshida, H; Christensen, T H; Guildal, T; Scheutz, C



Anaerobic treatment of complex wastewater and waste activated sludge - Appl. of an upflow anaerobic solid removal (UASR)  

Microsoft Academic Search

The application of one phase anaerobic wastewater systems for the treatment of complex wastewaters containing high amounts of suspended solids or lipids is usually limited by accumulation of these compounds in the sludge bed. This accumulation reduces the solid retention time and methanogenic activity of the sludge. The aim of the presented research was to achieve removal of suspended solids

G. Zeeman; W. T. M. Sanders; K. Y. Wang; G. Lettinga



The comparative mycological analysis of wastewater and sewage sludges from selected wastewater treatment plants  

Microsoft Academic Search

The wastewater and sewage sludge, which are rich in organic matter, are habitat for many groups of microorganisms, such as viruses, bacteria, fungi, algae, protozoa and worms. Many of them could turn out be plant, animal or human parasites, however in a routine analysis are almost never looked for. The main subject of the study was comparative analysis of microscopic

M. Kacprzak; E. Neczaj; E. Okoniewska



Wastewater sludge management options for Honduras  

E-print Network

Sludge management is a fundamental area of concern across wastewater treatment systems in Honduras. The lack of timely sludge removal has led to declining plant performance in many facilities throughout the country. In ...

Bhattacharya, Mahua, M. Eng. Massachusetts Institute of Technology.



Formation of abiological granular sludge - a facile and bioinspired proposal for improving sludge settling performance during heavy metal wastewater treatment.  


Heavy metal contamination in wastewater poses a severe threat to the environment and public health. Chemical precipitation is the most conventional process for heavy metal wastewater treatment. However, the flocculent structure of chemical precipitation sludge raises the problem of poor sludge settling performance that is difficult to overcome. Inspired by the biological granular sludge (BGS) formation process, we report here a facile and effective strategy to produce abiological granular sludge (ABGS) to solve this problem. In this procedure, controlled double-jet precipitation was performed to simulate the cell multiplication process in BGS formation by controlling the solution supersaturation. Meanwhile, ZnO seeds and flocculant polyacrylamide were added to simulate the role of nuclei growth and extracellular polymeric substances in BGS formation process, respectively. This procedure generates ABGS with a dense structure, large size and regular spherical morphology. The settling velocity of ABGS can reach up to 3.0cms(-1), significantly higher than that of flocculent sludge (<1cms(-1)). PMID:25065787

Yan, Xu; Li, Qingzhu; Chai, Liyuan; Yang, Bentao; Wang, Qingwei



Mechanisms involved in Escherichia coli and Serratia marcescens removal during activated sludge wastewater treatment.  


Wastewater treatment reduces environmental contamination by removing gross solids and mitigating the effects of pollution. Treatment also reduces the number of indicator organisms and pathogens. In this work, the fates of two coliform bacteria, Escherichia coli and Serratia marcescens, were analyzed in an activated sludge process to determine the main mechanisms involved in the reduction of pathogenic microorganisms during wastewater treatment. These bacteria, modified to express green fluorescent protein, were inoculated in an activated sludge unit and in batch systems containing wastewater. The results suggested that, among the different biological factors implied in bacterial removal, bacterivorous protozoa play a key role. Moreover, a representative number of bacteria persisted in the system as free-living or embedded cells, but their distribution into liquid or solid fractions varied depending on the bacterium tested, questioning the real value of bacterial indicators for the control of wastewater treatment process. Additionally, viable but nonculturable cells constituted an important part of the bacterial population adhered to solid fractions, what can be derived from the competition relationships with native bacteria, present in high densities in this environment. These facts, taken together, emphasize the need for reliable quantitative and qualitative analysis tools for the evaluation of pathogenic microbial composition in sludge, which could represent an undefined risk to public health and ecosystem functions when considering its recycling. PMID:25044599

Orruño, Maite; Garaizabal, Idoia; Bravo, Zaloa; Parada, Claudia; Barcina, Isabel; Arana, Inés



Mechanisms involved in Escherichia coli and Serratia marcescens removal during activated sludge wastewater treatment  

PubMed Central

Wastewater treatment reduces environmental contamination by removing gross solids and mitigating the effects of pollution. Treatment also reduces the number of indicator organisms and pathogens. In this work, the fates of two coliform bacteria, Escherichia coli and Serratia marcescens, were analyzed in an activated sludge process to determine the main mechanisms involved in the reduction of pathogenic microorganisms during wastewater treatment. These bacteria, modified to express green fluorescent protein, were inoculated in an activated sludge unit and in batch systems containing wastewater. The results suggested that, among the different biological factors implied in bacterial removal, bacterivorous protozoa play a key role. Moreover, a representative number of bacteria persisted in the system as free-living or embedded cells, but their distribution into liquid or solid fractions varied depending on the bacterium tested, questioning the real value of bacterial indicators for the control of wastewater treatment process. Additionally, viable but nonculturable cells constituted an important part of the bacterial population adhered to solid fractions, what can be derived from the competition relationships with native bacteria, present in high densities in this environment. These facts, taken together, emphasize the need for reliable quantitative and qualitative analysis tools for the evaluation of pathogenic microbial composition in sludge, which could represent an undefined risk to public health and ecosystem functions when considering its recycling. PMID:25044599

Orruño, Maite; Garaizabal, Idoia; Bravo, Zaloa; Parada, Claudia; Barcina, Isabel; Arana, Inés



Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatment.  


Terylene artificial silk printing and dyeing wastewater (TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed (EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids (VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%-64%, pH stabilized in a range of 7.99-8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment. PMID:16083115

Guan, Bao-Hong



XRF and leaching characterization of waste glasses derived from wastewater treatment sludges  

Microsoft Academic Search

Purpose of this study was to investigate use of XRF (x-ray fluorescence spectrometry) as a near real-time method to determine melter glass compositions. A range of glasses derived from wastewater treatment sludges associated with DOE sites was prepared. They were analyzed by XRF and wet chemistry digestion with atomic absorption\\/inductively coupled emission spectrometry. Results indicated good correlation between these two




Metaproteomics Provides Functional Insight into Activated Sludge Wastewater Treatment  

PubMed Central

Background Through identification of highly expressed proteins from a mixed culture activated sludge system this study provides functional evidence of microbial transformations important for enhanced biological phosphorus removal (EBPR). Methodology/Principal Findings A laboratory-scale sequencing batch reactor was successfully operated for different levels of EBPR, removing around 25, 40 and 55 mg/l P. The microbial communities were dominated by the uncultured polyphosphate-accumulating organism “Candidatus Accumulibacter phosphatis”. When EBPR failed, the sludge was dominated by tetrad-forming ?-Proteobacteria. Representative and reproducible 2D gel protein separations were obtained for all sludge samples. 638 protein spots were matched across gels generated from the phosphate removing sludges. 111 of these were excised and 46 proteins were identified using recently available sludge metagenomic sequences. Many of these closely match proteins from “Candidatus Accumulibacter phosphatis” and could be directly linked to the EBPR process. They included enzymes involved in energy generation, polyhydroxyalkanoate synthesis, glycolysis, gluconeogenesis, glycogen synthesis, glyoxylate/TCA cycle, fatty acid ? oxidation, fatty acid synthesis and phosphate transport. Several proteins involved in cellular stress response were detected. Conclusions/Significance Importantly, this study provides direct evidence linking the metabolic activities of “Accumulibacter” to the chemical transformations observed in EBPR. Finally, the results are discussed in relation to current EBPR metabolic models. PMID:18392150

Wilmes, Paul; Wexler, Margaret; Bond, Philip L.



Effects of chemical sludge disintegration on the performances of wastewater treatment by membrane bioreactor.  


A new wastewater treatment process combining a membrane bioreactor (MBR) with chemical sludge disintegration was tested in bench scale experiments. In particular, the effects of the disintegration treatment on the excess sludge production in MBR were investigated. Two MBRs were operated. In one reactor, a part of the mixed liquor was treated with NaOH and ozone gas consecutively and was returned to the bioreactor. The flow rate of the sludge disintegration stream was 1.5% of the influent flow rate. During the 200 days of operation, the MLSS level in the bioreactor with the disintegration treatment was maintained relatively constant at the range of 10,000-11,000 mg/L while it increased steadily up to 25,000 mg/L in the absence of the treatment. In the MBR with the sludge disintegration, relatively constant transmembrane pressures (TMPs) could be maintained for more than 6 months while the MBR without disintegration showed an abrupt increase of TMP in the later phase of the operation. In conclusion, a complete control of excess sludge production in the membrane-coupled bioreactor was possible without significant deterioration of the treated water quality and membrane performances. PMID:17451782

Oh, Young-Khee; Lee, Ki-Ryong; Ko, Kwang-Baik; Yeom, Ick-Tae



Energy self-sufficient sewage wastewater treatment plants: is optimized anaerobic sludge digestion the key?  


The anaerobic digestion of primary and waste activated sludge generates biogas that can be converted into energy to power the operation of a sewage wastewater treatment plant (WWTP). But can the biogas generated by anaerobic sludge digestion ever completely satisfy the electricity requirements of a WWTP with 'standard' energy consumption (i.e. industrial pollution not treated, no external organic substrate added)? With this question in mind, we optimized biogas production at Prague's Central Wastewater Treatment Plant in the following ways: enhanced primary sludge separation; thickened waste activated sludge; implemented a lysate centrifuge; increased operational temperature; improved digester mixing. With these optimizations, biogas production increased significantly to 12.5 m(3) per population equivalent per year. In turn, this led to an equally significant increase in specific energy production from approximately 15 to 23.5 kWh per population equivalent per year. We compared these full-scale results with those obtained from WWTPs that are already energy self-sufficient, but have exceptionally low energy consumption. Both our results and our analysis suggest that, with the correct optimization of anaerobic digestion technology, even WWTPs with 'standard' energy consumption can either attain or come close to attaining energy self-sufficiency. PMID:24185054

Jenicek, P; Kutil, J; Benes, O; Todt, V; Zabranska, J; Dohanyos, M



A Cost-Effectiveness Analysis of Seminatural Wetlands and Activated Sludge Wastewater-Treatment Systems  

NASA Astrophysics Data System (ADS)

A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation was established to solve the problem of the different levels of dilution that characterize the inflow water of the different systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services, and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of 2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed. In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.

Mannino, Ilda; Franco, Daniel; Piccioni, Enrico; Favero, Laura; Mattiuzzo, Erika; Zanetto, Gabriele




EPA Science Inventory

This publication provides an updated status report on the number and type of oxygen-activated sludge facilities in operation, under construction, and being designed. It describes in detail the latest EPA supported oxygenation research and demonstration project, an evaluation of t...


Sludge valorization from wastewater treatment plant to its application on the ceramic industry.  


The main aim of this study is to assess the effect of incorporating waste sludge on the properties and microstructure of clay used for bricks manufacturing. Wastewater treatment plants produce annually a great volume of sludge. Replacing clay in a ceramic body with different proportions of sludge can reduce the cost due to the utilization of waste and, at the same time, it can help to solve an environmental problem. Compositions were prepared with additions of 1%, 2.5%, 5%, 7.5%, 10% and 15% wt% waste sludge in body clay. In order to determine the technological properties, such as bulk density, linear shrinkage, water suction, water absorption and compressive strength, press-moulded bodies were fired at 950 °C for coherently bonding particles in order to enhance the strength and the other engineering properties of the compacted particles. Thermal heating destroys organic remainder and stabilizes inorganic materials and metals by incorporating oxides from the elemental constituent into a ceramic-like material. Results have shown that incorporating up to 5 wt% of sludge is beneficial for clay bricks. By contrast, the incorporation of sludge amounts over 5 wt% causes deterioration on the mechanical properties, therefore producing low-quality bricks. PMID:21723033

Martínez-García, C; Eliche-Quesada, D; Pérez-Villarejo, L; Iglesias-Godino, F J; Corpas-Iglesias, F A



Reduction in excess sludge production in a dairy wastewater treatment plant via nozzle-cavitation treatment: case study of an on-farm wastewater treatment plant.  


Nozzle-cavitation treatment was used to reduce excess sludge production in a dairy wastewater treatment plant. During the 450-d pilot-scale membrane bioreactor (MBR) operation, when 300 l of the sludge mixed liquor (1/10 of the MBR volume) was disintegrated per day by the nozzle-cavitation treatment with the addition of sodium hydrate (final concentration: 0.01% W/W) and returned to the MBR, the amount of excess sludge produced was reduced by 80% compared with that when sludge was not disintegrated. On the basis of the efficiency of CODCr removal and the ammonia oxidation reaction, it was concluded that the nozzle-cavitation treatment did not have a negative impact on the performance of the MBR. The estimation of the inorganic material balance showed that when the mass of the excess sludge was decreased, the inorganic content of the activated sludge increased and some part of the inorganic material was simultaneously solubilized in the effluent. PMID:19246193

Hirooka, Kayako; Asano, Ryoki; Yokoyama, Atsushi; Okazaki, Masao; Sakamoto, Akira; Nakai, Yutaka



Occurrence, distribution and potential affecting factors of antibiotics in sewage sludge of wastewater treatment plants in China.  


The occurrence and distribution of eight quinolones, nine sulfonamides, and five macrolides were investigated in sewage sludge from 45 wastewater treatment plants in 23 cities in China. Among all the antibiotics considered, quinolones were the dominant antibiotics detected in all samples [total concentrations up to 8905 ?g/kg, dry weight (dw)], followed by macrolides (85.1 ?g/kg, dw), and sulfonamides (22.7 ?g/kg, dw). High concentrations of quinolones in sewage sludge indicated that antibiotics are widely used and extensive pollutants in China. Significant differences were observed for the total concentrations of antibiotics in sludge samples among the 45 WWTPs. To evaluate the potential factors affecting the antibiotic levels in sewage sludge, wastewater and sludge characteristics, as well as the operational conditions and treatment techniques in WWTPs were investigated. The results indicated that the antibiotic levels in sewage sludge depend to a great extent on wastewater characteristics. Significant correlation between total organic carbon (TOC) and total concentrations of antibiotics was also found in studied WWTPs, indicating that TOC could affect the sludge adsorption capability to the antibiotics to some extent. Moreover, the relation between treatment techniques and the total concentrations of antibiotics in sludge showed that antibiotic levels in sludge increased with longer solid retention time. PMID:23340024

Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi



Analysis of metals and EOX in sludge from municipal wastewater treatment plants: a case study.  


The monitoring of extractable organic halogen (EOX) and heavy metal contents in sludge coming from 10 different municipal wastewater treatment plants (MWWTP) located in Friuli Venezia Giulia (Italy) is reported. In this work, sludge samples drawn from sludge treatment units have been digested and analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for metal evaluation. Samples were also extracted and analyzed by microcoulometric titrations, following modified DIN 38414 T17 standard, for EOX analysis. Analytical results showed a slight enrichment of the contents of certain metals (Cd< 2mg/kg, Cr< 51.5mg/kg, Cu<105.8 mg/kg, Hg<1.4 mg/kg, Ni<35.9 mg/kg, Pb<58.7 mg/kg, Zn<410.1 mg/kg, Ba<317.1 mg/kg, Co<1 mg/kg, Mo< 5 mg/kg, Mn<106.7 mg/kg), so almost all of the sludge would be suitable for agricultural use following Italian and European regulations. The evaluation of EOX was carried out by using hexane and ethyl acetate as extraction solvents, and a measurable organic halogen content (ranging from 0.31 to 39.5 mg Cl/kg DM) was clearly detected in the sludge. The lowest concentrations of EOX were found in sludge coming from the smallest MWWTPs, which is to be considered more suitable for agricultural use. Additionally, analytical assays on composts, peat and soils were performed to compare EOX concentrations between these matrices and sludge. PMID:15905082

Goi, Daniele; Tubaro, Franco; Dolcetti, Giuliano



[Detection of anaerobic processes and microorganisms in immobilized activated sludge of a wastewater treatment plant with intense aeration].  


Attached activated sludge from the Krasnaya Polyana (Sochi) wastewater treatment plant was studied after the reconstruction by increased aeration and water recycle, as well as by the installation of a bristle carrier for activated sludge immobilization. The activated sludge biofilms developing under conditions of intense aeration were shown to contain both aerobic and anaerobic microorganisms. Activity of a strictly anaerobic methanogenic community was revealed, which degraded organic compounds to methane, further oxidized by aerobic methanotrophs. Volatile fatty acids, the intermediates of anaerobic degradation of complex organic compounds, were used by both aerobic and anaerobic microorganisms. Anaerobic oxidation of ammonium with nitrite (anammox) and the presence of obligate anammox bacteria were revealed in attached activated sludge biofilms. Simultaneous aerobic and anaerobic degradation of organic contaminants by attached activated sludge provides for high rates of water treatment, stability of the activated sludge under variable environmental conditions, and decreased excess sludge formation. PMID:25509405

Litti, Iu V; Nekrasova, V K; Kulikov, N I; Siman'kova, M V; Nozhevnikova, A N



Preparation and characteristics of bacterial polymer using pre-treated sludge from swine wastewater treatment plant.  


Sterilization, alkaline-thermal, and acid-thermal treatments were applied to different suspended sludge solids (SSS) concentrations and the pre-treated sludge was used as raw material for bioflocculant-producing bacteria R3 to produce bioflocculant. After 60 h of fermentation, three forms of bioflocculant (broth, capsular, and slime) were extracted, and maximum broth bioflocculant of 2.9 and 4.1 g L(-1) were produced in sterilized and alkaline-thermal treated sludge as compared to that of 1.8 g L(-1) in acid-thermal treated sludge. Higher bioflocculant quantity was produced in SS of 15, 25, and 35 g L(-1) compared to that produced in SS of 45, 55, and 65 g L(-1). Bioflocculant combined with 0.5 g Ca(2+) in 1.0 L kaolin suspension acted as conditioning agent, and maximum flocculating activity of 94.5% and 92.8% was achieved using broth and slime bioflocculant, respectively. The results demonstrated that wastewater sludge could be used as sources to prepare bioflocculants. PMID:24333626

Guo, Junyuan; Yang, Chunping; Peng, Lanyan



Effect of wastewater treatment processes on the pyrolysis properties of the pyrolysis tars from sewage sludges  

NASA Astrophysics Data System (ADS)

The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 °C/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.

Wu, Xia; Xie, Li-Ping; Li, Xin-Yu; Dai, Xiao-Hong; Fei, Xue-Ning; Jiang, Yuan-Guang



Anaerobic digestion and gasification coupling for wastewater sludge treatment and recovery.  


Sewage sludge management is an energy intensive process. Anaerobic digestion contributes to energy efficiency improvement but is limited by the biological process. A review has been conducted prior to experimentation in order to evaluate the mass and energy balances on anaerobic digestion followed by gasification of digested sludge. The purpose was to improve energy recovery and reuse. Calculations were based on design parameters and tests that are conducted with the anaerobic digester of a local wastewater treatment plant and a small commercial gasification system. Results showed a very significant potential of energy recovery. More than 90% of the energy content from sludge was extracted. Also, approximately the same amount of energy would be transferred in both directions between the digester (biogas) and the gasifier (thermal energy). This extraction resulted in the same use of biogas as the reference scenario but final product was a totally dry biochar, which represented a fraction of the initial mass. Phosphorus was concentrated and significantly preserved. This analysis suggests that anaerobic digestion followed by dehydration, drying and gasification could be a promising and viable option for energy and nutrient recovery from municipal sludge in replacement of conventional paths. PMID:24972600

Lacroix, Nicolas; Rousse, Daniel R; Hausler, Robert



Analysis and advanced oxidation treatment of a persistent pharmaceutical compound in wastewater and wastewater sludge-carbamazepine.  


Pharmaceutically active compounds (PhACs) are considered as emerging environmental problem due to their continuous input and persistence to the aquatic ecosystem even at low concentrations. Among them, carbamazepine (CBZ) has been detected at the highest frequency, which ends up in aquatic systems via wastewater treatment plants (WWTPs) among other sources. The identification and quantification of CBZ in wastewater (WW) and wastewater sludge (WWS) is of major interest to assess the toxicity of treated effluent discharged into the environment. Furthermore, WWS has been subjected for re-use either in agricultural application or for the production of value-added products through the route of bioconversion. However, this field application is disputable due to the presence of these organic compounds and in order to protect the ecosystem or end users, data concerning the concentration, fate, behavior as well as the perspective of simultaneous degradation of these compounds is urgently necessary. Many treatment technologies, including advanced oxidation processes (AOPs) have been developed in order to degrade CBZ in WW and WWS. AOPs are technologies based on the intermediacy of hydroxyl and other radicals to oxidize recalcitrant, toxic and non-biodegradable compounds to various by-products and eventually to inert end products. The purpose of this review is to provide information on persistent pharmaceutical compound, carbamazepine, its ecological effects and removal during various AOPs of WW and WWS. This review also reports the different analytical methods available for quantification of CBZ in different contaminated media including WW and WWS. PMID:24140682

Mohapatra, D P; Brar, S K; Tyagi, R D; Picard, P; Surampalli, R Y



Application of hydrothermal oxidation and alkaline hydrothermal gasification for the treatment of sewage sludge and pharmaceutical wastewaters  

Microsoft Academic Search

Hydrothermal treatment involving the oxidation and gasification of sewage sludge and pharmaceutical wastewater samples has been carried out in batch autoclave reactor. The efficiency of the oxidation processes measured in terms of total organic carbon (TOC) and total solids (TS) removal showed that effective sample treatments were achieved at moderately low temperatures of 350–450°C. More than 90% TOC removal was

Jude A. Onwudili; Pushpa Radhakrishnan; Paul T. Williams



Short-Term Effects of Low pH on the Microfauna of an Activated Sludge Wastewater Treatment System  

Microsoft Academic Search

Optimum pH for biological (e.g., activated sludge) wastewater treatment is stat- ed to lie between pH 6.5 and 8.0; however, the pH of processed effluent from thermomechanical pulp mills is closer to 4.5 and 5.5. Consequently, pH adjust- ment of effluent is required with associated costs. The ability of the microfaunal community (protozoa and metazoa) of activated sludge to survive




Occurrence and analysis of parabens in municipal sewage sludge from wastewater treatment plants in Madrid (Spain).  


A rapid method for determination of seven parabens and two chlorinated by-products in sewage sludge was developed based on matrix solid-phase dispersion and gas chromatography-tandem mass spectrometry. The analytical procedure showed good recoveries that ranged from 80 to 125%, with relative standard deviations lower than 12% and low detection limits, ranging from 0.1 to 2.0 ng g(-1) dry weight. The developed method was applied to the analysis of sewage sludge collected during 2010 in 19 wastewater treatment plants (WWTPs) located in various urban, industrial or rural zones in Madrid (Spain). Methylparaben was found in most of the WWTPs sampled (95%) at levels between 5.1 and 26.2 ng g(-1) dry weight and propylparaben was detected in 74% of the WWTPs at levels up to 44.1 ng g(-1) dry weight. In order to study the temporal variation of parabens and two chlorinated parabens during a four-year period, sludge samples were collected from 3 selected WWTPs. The levels of methylparaben encountered were rather constant throughout the sampling period whereas propylparaben levels slightly increased. In one of the WWTPs monitored, isopropylparaben was found at the beginning of the sampling period but its content decreased and was not detected in the 2010 sampling. PMID:22640822

Albero, Beatriz; Pérez, Rosa Ana; Sánchez-Brunete, Consuelo; Tadeo, José Luis



High-rate wastewater treatment by aerobic upflow sludge blanket reactor: system performance and characteristics.  


A laboratory study was conducted to investigate the characteristics of an aerobic upflow sludge blanket reactor (AUSB) treating synthetic wastewater at a high organic loading. The response of the system was evaluated at different operating conditions, such as pressurization, extent of flow recirculation, and hydraulic retention time. Aeration shear to the biomass in the reactor was totally eliminated by employing oxygenation under pressurization in an external chamber. As a result, the biomass concentration in the reactor could be maintained at 7-10 g VSS l(-1). The AUSB system was able to handle efficiently a volumetric loading of as high as 3.8 kg TOC m(-3) d(-1), which was possibly due to high reactor biomass level and higher bioactivity as indicated by higher sludge specific oxygen uptake rates. However, the treatment capacity of the AUSB was somewhat limited by the substrate and oxygen transport in the sludge bed due to low mixing intensity. The effluent TOC of the AUSB system was relatively higher due to its operation at a high organic loading. The AUSB system performed well under a short term loading shock, and the bacterial activity in the oxygenation chamber was demonstrated to contribute to its improved substrate removal capacity under the shock loading. PMID:15691202

Sharma, K R; Huang, J C




EPA Science Inventory

There are potential environmental concerns from the disposal of municipal wastewater effluents and sewage treatment plant sludges. This report summarizes the microbial mutagenic evaluation and chemical analysis of 13 sewage sludge samples from various sewage treatment plants loca...


Essence of disposing the excess sludge and optimizing the operation of wastewater treatment: rheological behavior and microbial ecosystem.  


Proper disposal of excess sludge and steady maintenance of the high bioactivity of activated sludge in bioreactors are essential for the successful operation of wastewater treatment plants (WWTPs). Since sludge is a non-Newtonian fluid, the rheological behavior of sludge can therefore have a significant impact on various processes in a WWTP, such as fluid transportation, mixing, oxygen diffusion, mass transfer, anaerobic digestion, chemical conditioning and mechanical dewatering. These are key factors affecting the operation efficiency and the energy consumption of the entire process. In the past decade-due to the production of large quantities of excess sludge associated with the extensive construction of WWTPs and the emergence of some newly-developed techniques for wastewater purification characterized by high biomass concentrations-investigations into the rheology of sludge are increasingly important and this topic has aroused considerable interests. We reviewed a number of investigations into the rheology of sludge, with the purpose of providing systematic and detailed analyses on the related aspects of the rheological behavior of sludge. It is clear that, even though considerable research has focused on the rheology of sludge over a long time period, there is still a need for further thorough investigation into this field. Due to the complex process of bio-treatment in all WWTPs, biological factors have a major influence on the properties of sludge. These influences are however still poorly understood, particularly with respect to the mechanisms involved and magnitude of such impacts. When taking note of the conspicuous biological characteristics of sludge, it becomes important that biological factors, such as the species composition and relative abundance of various microorganisms, as well as the microbial community characteristics that affect relevant operating processes, should be considered. PMID:24462086

Tang, Bing; Zhang, Zi




EPA Science Inventory

Bacteria and virus-containing aerosols were studied during late summer and fall in a U.S. midwestern suburb before and during the start up and operation of an unenclosed activated sludge wastewater treatment plant. The air in this suburban area contained low-level densities of in...


Aggregation behavior of engineered nanoparticles and their impact on activated sludge in wastewater treatment.  


The ever-increasing daily use of engineered nanoparticles will lead to heightened levels of these materials in the environment. These nanomaterials will eventually go into the wastewater treatment plant (WWTP), therefore, resulting into a pressing need for information on their aggregation behavior and kinetics in the wastewater aqueous matrix. In this work, we dispersed two different metal oxide nanoparticles (ZnO and TiO2) into the influent of two different WWTPs. Through the time-resolved dynamic light scattering analysis and transmission electron microscopy, the metal oxide nanoparticles (NPs) were quite stably existed in the wastewater matrix with aggregates of diameter 300-400 nm after 4.5h or more suspension. We confirmed that the dissolved organic matters (DOMs) attributed to the stability of nanoparticles. No propensity of NPs to aggregate were observed in the presence of both monovalent and divalent electrolytes even at high concentrations up to 0.15 M in NaCl or 0.025 M in CaCl2, indicating that the destabilization of nanoparticles in the complicated wastewater matrix was not achieved by the compression of electrical double layer, therefore, their aggregation kinetics cannot be simply predicted by the classic Derjaguin-Landau-Verwey-Overbeek theory of colloidal stability. However, obvious aggregation of nanoparticles in the Al2(SO4)3 solution system was observed with the likely mechanism of bridging of the metal oxide nanoparticles and aggregates due to the formation of hydrous alumina (Al(OH)3·H2O) in the Al2(SO4)3 solution. In the wastewater matrix, we used the noninvasive measurement technology to detect the O2 flux of activated sludge before and after treatment with 1, 10 and 100 mg L(-1) NPs. The results confirmed that both ZnO and TiO2 NPs showed an adverse impact on the O2 uptake of activated sludge when the exposure time extended to 4.5 h. PMID:25127355

Zhou, Xiao-hong; Huang, Bao-cheng; Zhou, Tao; Liu, Yan-chen; Shi, Han-chang



Improving the Biotreatment of Hydrocarbons-Contaminated Soils by Addition of Activated Sludge taken from the Wastewater Treatment Facilities of an Oil Refinery  

Microsoft Academic Search

Addition of activated sludge taken from the wastewater treatment facilities ofan oil refinery to a soil contaminated with oily sludge stimulated hydrocarbonbiodegradation in microcosms, bioreactors and biopile. Microcosms containing50 g of soil to which 0.07 % (w\\/w) of activated sludge was added presented ahigher degradation of alkanes (80 % vs 24 %) and polycyclic aromatic hydrocarbons(PAHs) (77 % vs 49

Pierre Juteau; Jean-Guy Bisaillon; François Lépine; Valérie Ratheau; Réjean Beaudet; Richard Villemur



Co-treatment of domestic and dairy wastewater in an activated sludge system.  


This research assesses the potential for co-treatment of a dairy wastewater with a domestic wastewater in a lab-scale, continuous-flow, activated sludge system. To evaluate the influence of the dairy waste contribution, seven runs were conducted with each run being a mixture of dairy wastewater (either cheese or milk) in different ratios ranging from 1:0.01 to 1:0.30 by volume. More than 87% of the carbon was removed for both waste additions; however, while 95% ammonia-nitrogen removal was recorded for the cheese waste, only 75% removal was obtained for the milk. Kinetic studies for carbon consumption revealed a first-order model with lower kinetic constants as the cheese waste proportion increased. Specific carbon consumption rates indicated that the biomass had not reached its maximum potential to degrade carbon. The ability of the biomass to settle was hindered when the Gram negative to Gram positive filamentous bacteria ratio increased to approximately 1.5. PMID:25204524

Sparchez, E; Elefsiniotis, P; Wareham, D G; Fongsatitkul, P



Bacterial community dynamics in a full-scale municipal wastewater treatment plant employing conventional activated sludge process.  


To elucidate the bacterial community dynamics in a full-scale wastewater treatment plant (WWTP) and the relatedness among bacterial communities in the influent, effluent and sludge, the structure and metabolic ability of the bacterial community throughout a full-scale WWTP employing a conventional activated sludge process was investigated during a period of 10 months. The bacterial community structure was analyzed by terminal-restriction fragment length polymorphism targeting eubacterial 16S rRNA genes, while a Biolog assay was applied to assess the metabolic ability of the activated sludge. Influent bacterial community structure was generally stable. In contrast, the bacterial community structure in the effluent was similar to that in the influent in some cases, while in other cases it was unique and differed greatly from that in the influent and sludge. These results suggest that temporal variations of the effluent bacterial community may be useful to predict the wastewater treatment performance and settleability of activated sludge. The bacterial community structure in the sludge was relatively stable and was rarely impacted by the influent populations. Biolog assay also revealed that activated sludge maintained a remarkably similar metabolic potential of organic compounds over time due to functional redundancy, in which the minor populations played a significant role. PMID:24480747

Hashimoto, Kurumi; Matsuda, Masami; Inoue, Daisuke; Ike, Michihiko



Pharmaceutically active compounds in sludge stabilization treatments: anaerobic and aerobic digestion, wastewater stabilization ponds and composting.  


Sewage sludge disposal onto lands has been stabilized previously but still many pollutants are not efficiently removed. Special interest has been focused on pharmaceutical compounds due to their potential ecotoxicological effects. Nowadays, there is scarce information about their occurrence in different sludge stabilization treatments. In this work, the occurrence of twenty-two pharmaceutically active compounds has been studied in sludge from four sludge stabilization treatments: anaerobic digestion, aerobic digestion, composting and lagooning. The types of sludge evaluated were primary, secondary, anaerobically-digested and dehydrated, composted, mixed, aerobically-digested and dehydrated and lagoon sludge. Nineteen of the twenty-two pharmaceutically active compounds monitored were detected in sewage sludge. The most contaminated samples were primary sludge, secondary sludge and mixed sludge (the average concentrations of studied compounds in these sludges were 179, 310 and 142 ?g/kg dm, respectively) while the mean concentrations found in the other types of sewage sludge were 70 ?g/kg dm (aerobically-digested sludge), 63 ?g/kg dm (lagoon sludge), 12 ?g/kg dm (composted sludge) and 8 ?g/kg dm (anaerobically-digested sludge). The antibiotics ciprofloxacin and norfloxacin were found at the highest concentration levels in most of the analyzed sludge samples (up to 2660 and 4328 ?g/kg dm, respectively). Anaerobic-digestion treatment reduced more considerably the concentration of most of the studied compounds than aerobic-digestion (especially in the case of bezafibrate and fluoroquinolones) and more than anaerobic stabilization ponds (in the case of acetaminophen, atenolol, bezafibrate, carbamazepine, 17?-ethinylestradiol, naproxen and salicylic acid). Ecotoxicological risk assessment, of sludge application onto soils, has also been evaluated. Risk quotients, expressed as the ratio between the predicted environmental concentration and the predicted non-effect concentration, were lower than 1 for all the pharmaceutically active compounds so no significant risks are expected to occur due to the application of sewage sludge onto soils, except for 17?-ethinylestradiol when chronic toxicity was considered. PMID:24909712

Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban



Concentrations and distribution of synthetic musks and siloxanes in sewage sludge of wastewater treatment plants in China.  


In this study, we assessed the occurrence and distribution patterns of seven synthetic musks (SMs) and 17 siloxanes in anaerobic digested sludge samples collected at the dewatering process from 42 wastewater treatment plants (WWTPs) in China. SMs in sludge from different WWTPs exhibited similar composition profiles, and their total concentrations ranged from 47.3 ng/g to 68.2 ?g/g dry weight (dw). On average, galaxolide (HHCB, 63.8%) and tonalide (AHTN, 31.7%) accounted for 95.5% of ?SMs. The total concentrations of cyclic siloxanes ranged from sludge indicated that both of them were widely used in China. Among the sludge samples from 42 WWTPs, the concentrations of both ?SMs and ?siloxanes had considerable variations. We investigated the influence of potential factors (wastewater and sludge characteristics, the treatment capacity, serving population, and the treatment techniques of WWTPs) on the levels of target compounds in sludge, and found that SMs were significantly (p<0.05) correlated with the total organic carbon (TOC) of the sludge and the serving population of WWTP. There were also strong correlations (p<0.05) between the treatment capacity of WWTPs and cyclic siloxanes, as well as between the TOC of the sludge and linear siloxanes. In addition, the ecological risks of SMs and siloxanes in sewage sludge addressed to land application were assessed, which suggested that there was a low risk to the soil environment. PMID:24463026

Liu, Nannan; Shi, Yali; Li, Wenhui; Xu, Lin; Cai, Yaqi



XRF and leaching characterization of waste glasses derived from wastewater treatment sludges  

SciTech Connect

Purpose of this study was to investigate use of XRF (x-ray fluorescence spectrometry) as a near real-time method to determine melter glass compositions. A range of glasses derived from wastewater treatment sludges associated with DOE sites was prepared. They were analyzed by XRF and wet chemistry digestion with atomic absorption/inductively coupled emission spectrometry. Results indicated good correlation between these two methods. A rapid sample preparation and analysis technique was developed and demonstrated by acquiring a sample from a pilot-scale simulated waste glass melter and analyzing it by XRF within one hour. From the results, XRF shows excellent potential as a process control tool for waste glass vitrification. Glasses prepared for this study were further analyzed for durability by toxicity characteristic leaching procedure and product consistency test and results are presented.

Ragsdale, R.G., Jr



Emission of artificial sweeteners, select pharmaceuticals, and personal care products through sewage sludge from wastewater treatment plants in Korea.  


Concern over the occurrence of artificial sweeteners (ASWs) as well as pharmaceuticals and personal care products (PPCPs) in the environment is growing, due to their high use and potential adverse effects on non-target organisms. The data for this study are drawn from a nationwide survey of ASWs in sewage sludge from 40 representative wastewater treatment plants (WWTPs) that receive domestic (WWTPD), industrial (WWTPI), or mixed (domestic plus industrial; WWTPM) wastewaters in Korea. Five ASWs (concentrations ranged from 7.08 to 5220 ng/g dry weight [dw]) and ten PPCPs (4.95-6930 ng/g dw) were determined in sludge. Aspartame (concentrations ranged from 28.4 to 5220 ng/g dw) was determined for the first time in sewage sludge. The median concentrations of ASWs and PPCPs in sludge from domestic WWTPs were 0.8-2.5 and 1.0-3.4 times, respectively, the concentrations found in WWTPs that receive combined domestic and industrial wastewaters. Among the five ASWs analyzed, the median environmental emission rates of aspartame through domestic WWTPs (both sludge and effluent discharges combined) were calculated to be 417 ?g/capita/day, followed by sucralose (117 ?g/capita/day), acesulfame (90 ?g/capita/day), and saccharin (66?g/capita/day). The per-capita emission rates of select PPCPs, such as antimicrobials (triclocarban: 158 ?g/capita/day) and analgesics (acetaminophen: 59 ?g/capita/day), were an order of magnitude higher than those calculated for antimycotic (miconazole) and anthelmintic (thiabendazole) drugs analyzed in this study. Multiple linear regression analysis of measured concentrations of ASWs and PPCPs in sludge revealed that several WWTP parameters, such as treatment capacity, population-served, sludge production rate, and hydraulic retention time could influence the concentrations found in sludge. PMID:24695211

Subedi, Bikram; Lee, Sunggyu; Moon, Hyo-Bang; Kannan, Kurunthachalam



Survey of keratinophilic fungi in sewage sludge from wastewater treatment plants of Mazandaran, Islamic Republic of Iran.  


To isolate keratinophilic fungi in sewage sludge from wastewater treatment plants in Sari city, Mazandaran province, Islamic Republic of Iran, samples were taken from 7 plants with different sewage treatment technologies. From 35 sludge samples cultured on Sabouraud's agar with cycloheximide and chloramphenicol, 326 fungal colonies belonging to 7 species were isolated. Geotrichum (59.5%), Cladosporium (13.8%), Alternaria (11.3%) and Penicillium (10.7%) species were the most prevalent. No growth of keratinophilic fungi was observed on this medium. However, using the hair-baiting technique, Microsporum gypseum, Chrysosporium spp. and Geotrichum spp. were isolated. PMID:19554993

Hedayati, M T; Mirzakhani, M



Fate of pathogenic microorganisms and indicators in secondary activated sludge wastewater treatment plants.  


This study was undertaken to investigate the removal of pathogenic microorganisms and their indicators in a laboratory scale biological treatment system that simulated the secondary treatment process of a wastewater treatment plant (WWTP). Four groups of microorganisms including bacteria, viruses, protozoa and helminths as well as the selected indicators were employed in the investigation. The results demonstrated that approximately 2-3 log10 removal of the microbial indicators was achieved in the treatment process. The log removal of Clostridium perfringens spores was low due to their irreversible adsorption to sludge flocs. The laboratory treatment system demonstrated a similar removal capability for Escherichia coli and the bacterial indicators (total coliforms, enterococci and particles <2.73 microm/L). The MS-2 bacteriophage, measured as a viral indicator, showed a lower removal than poliovirus, which may be considered as a worst case scenario for virus removal. The results of using particle profiling as an indicator for protozoa and helminths appeared to be inaccurate. The removal performance for bacterial and protozoan pathogens and their indicators in a full scale WWTP and the laboratory treatment system was compared. PMID:18977580

Wen, Qinxue; Tutuka, Candani; Keegan, Alexandra; Jin, Bo



6:2 Fluorotelomer alcohol aerobic biotransformation in activated sludge from two domestic wastewater treatment plants.  


6:2 Fluorotelomer alcohol [6:2 FTOH, F(CF2)6CH2CH2OH] is a major basic chemical being used to manufacture FTOH-based products. After the end of use, 6:2 FTOH-based products may be released to domestic wastewater treatment plants (WWTPs) as a first major environmental entry point. Activated sludge collected from two WWTPs was dosed with 6:2 FTOH to investigate its biotransformation rate and to identify major transformation products. The volatile 5:2 sFTOH [F(CF2)5CH(OH)CH3] is the most abundant transformation product and accounted for an average of 40mol% of initially dosed 6:2 FTOH after two months of incubation with activated sludge, with 30mol% detected in the headspace. PFPeA [F(CF2)4COOH] averaged 4.4mol% after two months, 2.4-7 times lower than that in sediment and soils. The much lower level of PFPeA formed in activated sludge compared with soil indicates that microbial populations in activated sludge may lack enzymes or suitable environment conditions to promote rapid 5:2 sFTOH decarboxylation to form PFPeA, resulting in more 5:2 sFTOH partitioned to the headspace. PFHxA [F(CF2)5COOH] and 5:3 [F(CF2)5CH2CH2COOH] acid are major non-volatile transformation products in activated sludge. For example, PFHxA averaged 11mol% after two months, which is about 30% higher compared with sediment and soils, suggesting that microbes in WWTPs may utilize similar pathways as that in sediment and soils to convert 5:2 sFTOH to PFHxA. 5:3 Acid averaged 14mol% after two months, comparable to that in soils and slightly lower than in sediment, further confirming that 5:3 acid is a unique product of 6:2 FTOH biotransformation in the environment. PMID:23540810

Zhao, Lijie; McCausland, Patricia K; Folsom, Patrick W; Wolstenholme, Barry W; Sun, Hongwen; Wang, Ning; Buck, Robert C



Molecular characterization of activated sludge from a seawater-processing wastewater treatment plant.  


The prokaryotic community composition of activated sludge from a seawater-processing wastewater treatment plant (Almeria, Spain) was investigated by using the rRNA approach, combining different molecular techniques such as denaturing gradient gel electrophoresis (DGGE), clone libraries and in situ hybridization (FISH and CARD-FISH). Most of the sequences retrieved in the DGGE and the clone libraries were similar to uncultured members of different phyla. The most abundant sequence recovered from Bacteria in the clone library corresponded to a bacterium from the Deinococcus-Thermus cluster (almost 77% of the clones), and the library included members from other groups such as the Alpha, Gamma and Delta subclasses of Proteobacteria, the Bacteroidetes and Firmicutes. Concerning the archaeal clone library, we basically found sequences related to different orders of methanogenic Archaea, in correspondence with the recovered DGGE bands. Enumeration of DAPI (4',6-diamidino-2-phenylindole) stained cells from two different activated sludge samples after a mechanical flocculation disruption revealed a mean cell count of 1.6 × 10(9) ml(-1) . Around 94% of DAPI counts (mean value from both samples) hybridized with a Bacteria specific probe. Alphaproteobacteria were the dominant bacterial group (36% of DAPI counts), while Beta-, Delta- and Gammaproteobacteria, Bacteroidetes, Actinobacteria and Firmicutes contributed to lower proportions (between 0.5-5.7% of DAPI counts). Archaea accounted only for 6% of DAPI counts. In addition, specific primers for amplification of the amoA (ammonia monooxygenase) gene were used to detect the presence of Beta, Gamma and archaeal nitrifiers, yielding positive amplifications only for Betaproteobacteria. This, together with negative in situ hybridizations with probes for well-known nitrifiying bacteria, suggests that nitrification is performed by still undetected microorganisms. In summary, the combination of the three approaches provided different and complementary pictures of the real assemblage composition and allowed to get closer to the main microorganisms involved in key processes of seawater-processing activated sludge. PMID:21414181

Sánchez, Olga; Garrido, Laura; Forn, Irene; Massana, Ramon; Maldonado, Manuel Ignacio; Mas, Jordi



Molecular characterization of activated sludge from a seawater?processing wastewater treatment plant  

PubMed Central

Summary The prokaryotic community composition of activated sludge from a seawater?processing wastewater treatment plant (Almeria, Spain) was investigated by using the rRNA approach, combining different molecular techniques such as denaturing gradient gel electrophoresis (DGGE), clone libraries and in situ hybridization (FISH and CARD?FISH). Most of the sequences retrieved in the DGGE and the clone libraries were similar to uncultured members of different phyla. The most abundant sequence recovered from Bacteria in the clone library corresponded to a bacterium from the Deinococcus–Thermus cluster (almost 77% of the clones), and the library included members from other groups such as the Alpha, Gamma and Delta subclasses of Proteobacteria, the Bacteroidetes and Firmicutes. Concerning the archaeal clone library, we basically found sequences related to different orders of methanogenic Archaea, in correspondence with the recovered DGGE bands. Enumeration of DAPI (4?,6?diamidino?2?phenylindole) stained cells from two different activated sludge samples after a mechanical flocculation disruption revealed a mean cell count of 1.6?×?109?ml?1. Around 94% of DAPI counts (mean value from both samples) hybridized with a Bacteria specific probe. Alphaproteobacteria were the dominant bacterial group (36% of DAPI counts), while Beta?, Delta? and Gammaproteobacteria, Bacteroidetes, Actinobacteria and Firmicutes contributed to lower proportions (between 0.5–5.7% of DAPI counts). Archaea accounted only for 6% of DAPI counts. In addition, specific primers for amplification of the amoA (ammonia monooxygenase) gene were used to detect the presence of Beta, Gamma and archaeal nitrifiers, yielding positive amplifications only for Betaproteobacteria. This, together with negative in situ hybridizations with probes for well?known nitrifiying bacteria, suggests that nitrification is performed by still undetected microorganisms. In summary, the combination of the three approaches provided different and complementary pictures of the real assemblage composition and allowed to get closer to the main microorganisms involved in key processes of seawater?processing activated sludge. PMID:21414181

Sánchez, Olga; Garrido, Laura; Forn, Irene; Massana, Ramon; Maldonado, Manuel Ignacio; Mas, Jordi



Advanced sludge treatment affects extracellular polymeric substances to improve activated sludge dewatering  

Microsoft Academic Search

The management of wastewater sludge, now often referred to as biosolids, accounts for a major portion of the cost of the wastewater treatment process and represents significant technical challenges. In many wastewater treatment facilities, the bottleneck of the sludge handling system is the dewatering operation. Advanced sludge treatment (AST) processes have been developed in order to improve sludge dewatering and

Elisabeth Neyens; Jan Baeyens; Raf Dewil; Bart De heyder



Studies on the survival of enterohemorrhagic and environmental Escherichia coli strains in wastewater and in activated sludges from dairy sewage treatment plants.  


Survival of Escherichia coli O157:H7 strain isolated from milk in Poland and an environmental E. coli strain in wastewater from Garwolin and ?owicz dairies and in activated sludges from dairy sewage treatment plants as well as in dairy wastewater with activated sludges was examined. Environmental materials were contaminated with about 10(8) of target bacteria/ml of sample. The experiments were performed under temperature conditions typical of autumn-winter (6 degrees) and spring-summer (24 degrees C) seasons. It was found that the non-pathogenic E. coli strain survived longer in all media than the enterohemorrhagic serotype. E. coli O157:H7 bacteria were not detected (in direct plating method) in activated sludges after 21-28 days; in dairy wastewater as well as in wastewater with activated sludges after 21-25 days. These periods for environmental E. coli strain were 35-42 days (activated sludges), 25-28 days (wastewater with activated sludges). At higher temperature environmental E. coli were not detected in wastewater from ?owicz dairy sewage treatment plant after 25 days, but the bacteria were still present in wastewater from Garwolin dairy sewage tratment plant after 34 days. The obtained results show that the lack of environmental E. coli bacteria (as a indicator bacteria of fecal contamination) in dairy wastewater and in dairy wastewater with activated sludges could indicate the absence of pathogenic E. coli bacteria. Prolonged existence of the enterohemorrhagic serotype in activated sludges shows the need to treat activated sludges prior to the utilization of these materials as fertilizer. PMID:18646405

Czajkowska, Danuta; Boszczyk-Maleszak, Hanka; Sikorska, I Rena; Sochaj, Agnieszka



Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters  

SciTech Connect

The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was investigated in laboratory-scale reactors at 30 C. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to 12 g COD/L [center dot] d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGSB reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V[sub up]) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K[sub s] value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V[sub up] lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A more important restriction of the EGSB reactor was the sludge washout occurring at V[sub up] higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L [center dot] d due to buoyancy forces from the gas production.

Kato, M.T.; Field, J.A.; Versteeg, P.; Lettinga, G. (Wageningen Agricultural Univ. (Netherlands). Dept. of Environmental Technology)



Biological prevention and removal of hydrogen sulphide in sludge at Lillehammer Wastewater Treatment Plant  

Microsoft Academic Search

Formation of H2S and other odorous compounds in sludge can be prevented efficiently by controlled dosage of nitrate. Lillehammer WWTP (N) had problems with malodour that originated mainly from the sludge treatment. High levels of H2S caused poor working conditions, and resulted in an overloaded hypochlorite scrubber. In addition, neighbours were complaining. Controlled dosing was necessary to avoid increased loads

A. M. Einarsen; A. Æsøy; A. I. Rasmussen; S. Bungum; M. Sveberg


Toxic influence of silver and uranium salts on activated sludge of wastewater treatment plants and synthetic activated sludge associates modeled on its pure cultures.  


Toxic impact of silver and uranium salts on activated sludge of wastewater treatment facilities has been studied. Some dominating cultures (an active nitrogen fixer Agrobacterium tumifaciens (A.t) and micromyces such as Fusarium nivale, Fusarium oxysporum, and Penicillium glabrum) have been isolated and identified as a result of selection of the activated sludge microorganisms being steadiest under stressful conditions. For these cultures, the lethal doses of silver amounted 1, 600, 50, and 300 µg/l and the lethal doses of uranium were 120, 1,500, 1,000, and 1,000 mg/l, respectively. A.tumifaciens is shown to be more sensitive to heavy metals than micromyces. Synthetic granular activated sludge was formed on the basis of three cultures of the isolated micromyces steadiest against stress. Its granules were much more resistant to silver than the whole native activated sludge was. The concentration of silver causing 50?% inhibition of synthetic granular activated sludge growth reached 160-170??g/l as far as for the native activated sludge it came only to 100-110??g/l. PMID:25027236

Tyupa, Dmitry V; Kalenov, Sergei V; Skladnev, Dmitry A; Khokhlachev, Nikolay S; Baurina, Marina M; Kuznetsov, Alexander Ye



Assessment of activated sludge microbial community analysis in full-scale biological wastewater treatment plants using patterns of fatty acid isopropyl esters (FAPEs)  

Microsoft Academic Search

This investigation introduces the application of a relatively rapid technique to obtain information about the dynamic nature of microbial communities in activated sludge. The objective has been to consider variability due to measurement errors and protocol changes within the same quantitative framework as the analysis of systematic differences in microbial communities in large-scale aerobic activated sludge secondary wastewater treatment systems.

Alan G. Werker; Jennifer Becker; Carly Huitema



Treatment of wastewater from a monosodium glutamate manufacturing plant using successive yeast and activated sludge systems  

Microsoft Academic Search

Successive systems using yeast and activated sludge (AS) were developed to treat monosodium glutamate manufacturing wastewater (MSGW). The yeast system allowed over 80% removal of chemical oxygen demand (COD) and a rise of pH from 2.5 to 6.5 on treating MSGW directly (COD 25,000mg\\/l and NH4+–N 19,000mg\\/l). Observation of the microbial community using a scanning electron microscope indicated that the

Qingxiang Yang; Min Yang; Shujun Zhang; Wenzhou Lv



Fate of Zinc Oxide Nanoparticles during Anaerobic Digestion of Wastewater and Post-Treatment Processing of Sewage Sludge  

SciTech Connect

The rapid development and commercialization of nanomaterials will inevitably result in the release of nanoparticles (NPs) to the environment. As NPs often exhibit physical and chemical properties significantly different from those of their molecular or macrosize analogs, concern has been growing regarding their fate and toxicity in environmental compartments. The wastewater-sewage sludge pathway has been identified as a key release pathway leading to environmental exposure to NPs. In this study, we investigated the chemical transformation of two ZnO-NPs and one hydrophobic ZnO-NP commercial formulation (used in personal care products), during anaerobic digestion of wastewater. Changes in Zn speciation as a result of postprocessing of the sewage sludge, mimicking composting/stockpiling, were also assessed. The results indicated that 'native' Zn and Zn added either as a soluble salt or as NPs was rapidly converted to sulfides in all treatments. The hydrophobicity of the commercial formulation retarded the conversion of ZnO-NP. However, at the end of the anaerobic digestion process and after postprocessing of the sewage sludge (which caused a significant change in Zn speciation), the speciation of Zn was similar across all treatments. This indicates that, at least for the material tested, the risk assessment of ZnO-NP through this exposure pathway can rely on the significant knowledge already available in regard to other 'conventional' forms of Zn present in sewage sludge.

Lombi, Enzo; Donner, Erica; Tavakkoli, Ehsan; Turney, Terence W.; Naidu, Ravi; Miller, Bradley W.; Scheckel, Kirk G. (U. South Australia); (EPA); (Monash)



Stabilization of heavy metals in wastewater treatment sludge from power plants air heater washing.  


In the present investigation, for the first time in Iran, dewatered sludge waste from the air heater washing wastewater treatment of a thermal power plant was subject to investigation with regard to cement-based stabilization in order to reduce the mobility of heavy metals. Studies of the chemical composition, mineralogy, morphology and leaching characteristics of the untreated and treated waste were conducted. The stabilization was done with two cement-based mix designs with different waste/cement ratios in different samples. In the cement stabilization process the leaching of V, Ni, Zn and Cr could be decreased from 314.1, 209.1, 24.8 and 5.5 mg L(-1), respectively, in the untreated waste to 6.02, 32.11, 3.57 and 3.68 mg L(-1) in a mixture with 20% waste/cement ratio, while during stabilization with cement + sand, the toxicity characteristic leaching procedure (TCLP) leachate contents of the mentioned metals were decreased to 4.24, 16.2, 2.51 and 2.2 mg L(-1) for the same waste/cement ratio. Stabilization with sand/cement seemed to be more efficient in reducing metal leaching from the waste. X-ray diffraction studies showed that portlandite, calcite, lime, larnite and quartz were produced during the stabilization process. PMID:19423607

Saeedi, Mohsen; Amini, Hamid Reza



Occurrence of PBDEs and other alternative brominated flame retardants in sludge from wastewater treatment plants in Korea.  


Studies on the occurrence of polybrominated diphenyl ethers (PBDEs) and other alternative brominated flame retardants in the environment are scarce. In this study, PBDEs and non-PBDE brominated flame retardants (NBFRs), including decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), were measured in sludge collected from three types of wastewater treatment plants (WWTPs) in Korea. Total concentrations of PBDEs (?PBDE) in sludge ranged from 298 to 48,000 (mean: 3240) ng/g dry weight. Among 10 NBFRs analyzed, DBDPE and BTBPE were the only ones detected in sludge samples. Concentrations of DBDPE and BTBPE ranged from sludge were higher than those reported in other countries. The highest concentrations of ?PBDE and DBDPE were found in sludge samples originated from industrial-WWTPs (I-WWTPs), suggesting that industrial activities are a major source of these contaminants. Non-parametric multidimensional scaling ordination showed that congener profiles of PBDEs in sludge are dependent on the types of WWTPs. Almost all sludge samples contained a low ratio (mean: 0.18) of DBDPE/BDE 209, indicating an on-going contamination by PBDEs in Korea. However, the high ratios (>1) of DBDPE/BDE 209 were found in sludge from I-WWTPs, reflecting a shift in the usage pattern of BFRs by the Korean industry. The nationwide annual emission fluxes of ?PBDE, DBDPE and BTBPE via WWTPs to the environment were estimated to be 7400, 480, and 3.7 kg/year, respectively. This is the first study on the occurrence of alternative brominated flame retardants in sludge from Korea. PMID:23993837

Lee, Sunggyu; Song, Geum-Ju; Kannan, Kurunthachalam; Moon, Hyo-Bang




Microsoft Academic Search

Anaerobic wastewater treatment differs from conventional aerobic treatment. The absence of oxygen leads to controlled conversion of complex organic pollutions, mainly to carbon dioxide and methane. Anaerobic treatment has favourable effects like removal of higher organic loading, low sludge production, high pathogen removal, biogas gas production and low energy consumption. Psychrophilic anaerobic treatment can be an attractive option to conventional

B. Mrowiec; J. Suschka


A Guide for Developing Standard Operating Job Procedures for the Activated Sludge - Aeration & Sedimentation Process Wastewater Treatment Facility. SOJP No. 5.  

ERIC Educational Resources Information Center

This guide for developing standard operating job procedures for wastewater treatment facilities is devoted to the activated sludge aeration and sedimentation process. This process is for conversion of nonsettleable and nonfloatable materials in wastewater to settleable, floculated biological groups and separation of the settleable solids from the…

Mason, George J.


Wastewater Treatment  

NSDL National Science Digital Library

This lesson introduces students to the basics of wastewater treatment. Topics include the variety of materials that enter the wastewater system, septic tanks, and municpal treatment systems. Students can review online resources that describe the processes of wastewater treatment and septic tank operation in detail, and listen to a National Publc Radio (NPR) show that discusses the use of treated wastewater to make snow at a ski resort in Maine. The lesson includes an activity in which students participate in virtual tours of wastewater treatment facilities and answer questions about what they see.

Laposata, Mark


Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter  

PubMed Central

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8?mg/L to 0.29?mg/L in TF, and NO3-N concentration increased from 8.8?mg/L to 27?mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple. PMID:23710197

Nourmohammadi, Davood; Esmaeeli, Mir-Bager; Akbarian, Hossein; Ghasemian, Mohammad




EPA Science Inventory

A wastewater aerosol monitoring program was conducted at an advanced wastewater treatment facility using the activated sludge process. This plant was recently constructed next to an elementary school in Tigard, Oregon. Wastewater aerosols containing pathogenic organisms are gener...


Enrichment of anammox bacteria from three sludge sources for the startup of monosodium glutamate industrial wastewater treatment system.  


Three activated sludges from a landfill leachate treatment plant (S1), a municipal sewage treatment plant (S2) and a monosodium glutamate (MSG) wastewater treatment plant (S3) were used as inocula to enrich anaerobic ammonium oxidation (anammox) bacteria for the startup of MSG industrial wastewater treatment system. After 360 days of cultivation using MSG wastewater, obvious anammox activity was observed in all three cultures. The maximum specific anammox activities of cultures S1, S2 and S3 were 0.11 kg N kg(-1) VSS day(-1), 0.09 kg N kg(-1) VSS day(-1) and 0.16 kg N kg(-1) VSS day(-1), respectively. Brownish-red anammox granules having diameters in the range of 0.2-1.0mm were visible in cultures S1 and S2, and large red granules having diameters in the range of 0.5-2.5mm were formed in culture S3 after 420 days of cultivation. Phylogenetic analysis of 16S rRNA genes showed that Kuenenia organisms were the dominant anammox species in all three cultures. The copy numbers of 16S rRNA genes of anammox bacteria in cultures S1, S2 and S3 were 6.8 × 10(7) copies mL(-1), 9.4 × 10(7) copies mL(-1) and 7.5 × 10(8) copies mL(-1), respectively. The results of this study demonstrated that anammox cultivation from conventional activated sludges was highly possible using MSG wastewater. Thus the anammox process has possibility of applying to the nitrogen removal from MSG wastewater. PMID:22104770

Li-dong, Shen; An-hui, Hu; Ren-cun, Jin; Dong-qing, Cheng; Ping, Zheng; Xiang-yang, Xu; Bao-lan, Hu



Treatment of saline wastewaters from marine-products processing factories by activated sludge reactor.  


An activated sludge reactor, operated at room temperature (20-30 degrees C) was used to treat saline wastewaters generated by marine-products industries. The system was operated continuously and the influence of the organic loading rates (OLRs), varying from 250 to 1000 mg COD l(-1) day(-1), on chemical oxygen demand (COD) removal was investigated. The system, inoculated with NaCl-acclimated culture, removed up to 98% and 88% of the influent COD concentrations at OLRs of 250 and 1000 mg COD L(-1) day(-1), respectively. Since the organic pollution is essentially composed of proteins, microorganisms, which produced proteolytic enzymes, were isolated from the activated sludge culture. One bacterium with the highest protease activity, identified as Bacillus cereus, was chosen for protease production in fishery wastewaters of different concentrations containing combined heads and viscera powder. Protease synthesis was strongly enhanced when cells were cultivated in two times diluted fishery wastewaters. The enhancement of protease synthesis could have been due to the presence in effluent of organic matters or salts, which stimulated the growth of the strain and protease production. PMID:14669806

Khannous, L; Souissi, N; Ghorbel, B; Jarboui, R; Kallel, M; Nasri, M; Gharsallah, N



Configuration of biological wastewater treatment line and influent composition as the main factors driving bacterial community structure of activated sludge.  


The structure of microbial consortia in wastewater treatment facilities is a resultant of environmental conditions created by the operational parameters of the purification process. In the research, activated sludge from nine Polish wastewater treatment plants (WWTPs) was investigated at a molecular level to determine the impact of the complexity of biological treatment line and the influent composition on the species structure and the diversity of bacterial consortia. The community fingerprints and technological data were subjected to the canonical correspondence and correlation analyses. The number of separated biological processes realized in the treatment line and the presence of industrial wastewater in the influent were the key factors determining the species structure of total and ammonia-oxidizing bacteria in biomass. The N2O-reducers community composition depended significantly on the design of the facility; the highest species richness of denitrifiers was noted in the WWTPs with separated denitrification tanks. The contribution of industrial streams to the inflow affected the diversity of total and denitrifying bacterial consortia and diminished the diversity of ammonia oxidizers. The obtained data are valuable for engineers since they revealed the main factors, including the design of wastewater treatment plant, influencing the microbial groups critical for the stability of purification processes. PMID:23397107

Jaranowska, Paulina; Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena



Phylogenetic and functional diversity of metagenomic libraries of phenol degrading sludge from petroleum refinery wastewater treatment system  

PubMed Central

In petrochemical refinery wastewater treatment plants (WWTP), different concentrations of pollutant compounds are received daily in the influent stream, including significant amounts of phenolic compounds, creating propitious conditions for the development of particular microorganisms that can rapidly adapt to such environment. In the present work, the microbial sludge from a refinery WWTP was enriched for phenol, cloned into fosmid vectors and pyrosequenced. The fosmid libraries yielded 13,200 clones and a comprehensive bioinformatic analysis of the sequence data set revealed a complex and diverse bacterial community in the phenol degrading sludge. The phylogenetic analyses using MEGAN in combination with RDP classifier showed a massive predominance of Proteobacteria, represented mostly by the genera Diaphorobacter, Pseudomonas, Thauera and Comamonas. The functional classification of phenol degrading sludge sequence data set generated by MG-RAST showed the wide metabolic diversity of the microbial sludge, with a high percentage of genes involved in the aerobic and anaerobic degradation of phenol and derivatives. In addition, genes related to the metabolism of many other organic and xenobiotic compounds, such as toluene, biphenyl, naphthalene and benzoate, were found. Results gathered herein demonstrated that the phenol degrading sludge has complex phylogenetic and functional diversities, showing the potential of such community to degrade several pollutant compounds. This microbiota is likely to represent a rich resource of versatile and unknown enzymes which may be exploited for biotechnological processes such as bioremediation. PMID:22452812



Enhanced nitrogen removal in the combined activated sludge-biofilter system of the Southpest Wastewater Treatment Plant.  


In 1999 the existing activated sludge unit of the Southpest Wastewater Treatment Plant was supplemented by a two-stage biofilter system aiming for nitrification and post-denitrification. In this arrangement excess biomass of the filters is wasted through the activated sludge unit, facilitating backseeding, and recirculation of the nitrate-rich effluent of the N-filter serves for decreasing the methanol demand of the DN-filter and for saving aeration energy at the same time. The paper reports on the development of an ASM1-based mathematical model that proved to be adequate for describing the interactions in the combined system and was used to compare the efficiency of different treatment options. Full-scale results verified that backseeding may considerably improve performance. However, nitrification ability of the activated sludge unit depends on the treatment temperature and, if unexpected, can be limited by insufficient oxygen supply. The upgrading possibilities outlined may serve as a new perspective for implementation of combined activated sludge-biofilter systems. PMID:15553452

Jobbágy, A; Tardy, G M; Literáthy, B



Sludge Treatment, Utilization, and Disposal.  

ERIC Educational Resources Information Center

Presents the 1978 literature review of wastewater treatment. This review covers such areas: (1) industrial and hazardous sludges; (2) chemical sludges; (3) stabilization and combustion; (4) ocean disposal; and (5) land application. A list of 411 references is also presented. (HM)

Dick, Richard I.



The role of stress agents as operating factors in formation and functioning of granular aerobic activated sludge at model domestic wastewater treatment.  


Maintenance of the wastewater treatment plants and increasing the efficiency of existing aerobic biological reactors depend on the stability of activated sludge characteristics under varying wastewater parameters within significant limits and/or influence of some environmental factors. The steady microbial communities observed in biofilms and anaerobic granules of activated sludge can serve as successful samples of formation of the similar aerobic systems. The granular aerobic sludge obtained in the course of our researches is an ideal "plant" on treatment of biogenic pollution at both low and high concentrations. It demonstrates high ability for treatment and stability to adverse factors. To improve aerobic wastewater treatment characteristics, a possibility of using impact of stress conditions upon activated sludge has been studied. Under conditions of fractional hydrogen peroxide addition at diffused lighting, the granular aerobic activated sludge adapted to hydrogen peroxide has been obtained. This sludge has got good sedimentary properties and it differs from the control sample in the species diversity, improved treatment characteristics and also resistance to the stressor. It also endures an impact of one-time hydrogen peroxide addition up to 1.2-1.5 g H2O2/l. The conditions under which the steady aerobic granules of the diameter from 2 to 5 mm were formed with high treatment ability have been chosen. The granules were being stabilized at passages with hydrogen peroxide treatment and they endured up to 2.4-3.0 g/l of one-time H2O2 addition. PMID:24556977

Khokhlachev, Nikolay S; Kalenov, Sergei V; Zanina, Olga S; Tyupa, Dmitry V; Baurina, Marina M; Kuznetsov, Alexander Ye




EPA Science Inventory

The efficiency of nitrogen stripping by intercropping forages with corn is evaluated in a three-year study at Muskegon County Wastewater Treatment Facility in Michign. Corn is grown as the major cash crop at the Muskegon treatment facility, but experience has shown that corn is n...



EPA Science Inventory

The investigations were carried out on laboratory scale, employing various mixtures of dyeing and municipal wastewaters. The processes studied were: coagulation, ozonization, chlorination, activated carbon, activated sludge, and anaerobic digestion. Lime appeared to be the best c...


Microbiological basis of phosphate removal in the activated sludge process for the treatment of wastewater  

Microsoft Academic Search

Several strains resembling members of theAcinetobacter-Moraxella-Mima group of bacteria were isolated from activated sludge-type sewage treatment plants designed for phosphate removal. The bacteria are obligate aerobes but utilize as carbon and energy sources low-molecular intermediates generated anaerobically, particularly acetate and ethanol. These bacteria can be shown to be responsible for the phosphate luxury uptake occurring in these treatment plants. The

G. W. Fuhs; Min Chen



Activated sludge wastewater treatment plant modelling and simulation: state of the art  

Microsoft Academic Search

This review paper focuses on modelling of wastewater treatment plants (WWTP). White-box modelling is widely applied in this field, with learning, design and process optimisation as the main applications. The introduction of the ASM model family by the IWA task group was of great importance, providing researchers and practitioners with a standardised set of basis models. This paper introduces the

Krist V. Gernaey; Mark C. M. Van Loosdrecht; Mogens Henze; Morten Lind; Sten B. Jørgensen




EPA Science Inventory

Tests were performed to determine the physical properties and chemical leaching characteristics of the residuals and the stabilized/solidified products from two publicly-owned wastewater treatment works (POTW). The two POTW waste products included in this study were an anaerobic ...


Occurrence, fate and ecotoxicological assessment of pharmaceutically active compounds in wastewater and sludge from wastewater treatment plants in Chongqing, the Three Gorges Reservoir Area.  


The occurrence, removal and ecotoxicological assessment of 21 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, antiepileptics, antilipidemics and antihypersensitives, were studied at four municipal wastewater treatment plants (WWTP) in Chongqing, the Three Gorges Reservoir Area. Individual treatment unit effluents, as well as primary and secondary sludge, were sampled and analyzed for the selected PhACs to evaluate their biodegradation, persistence and partitioning behaviors. PhACs were identified and quantified using high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. All the 21 analyzed PhACs were detected in wastewater and the target PhACs except acetaminophen, ibuprofen and gemfibrozil, were also found in sludge. The concentrations of the antibiotics and SVT were comparable to or even higher than those reported in developed countries, while the case of other target PhACs was opposite. The elimination of PhACs except acetaminophen was incomplete and a wide range of elimination efficiencies during the treatment were observed, i.e. from "negative removal" to 99.5%. The removal of PhACs was insignificant in primary and disinfection processes, and was mainly achieved during the biological treatment. Based on the mass balance analysis, biodegradation is believed to be the primary removal mechanism, whereas only about 1.5% of the total mass load of the target PhACs was removed by sorption. Experimentally estimated distribution coefficients (<500 L/kg, with a few exceptions) also indicate that biodegradation/transformation was responsible for the removal of the target PhACs. Ecotoxicological assessment indicated that the environment concentrations of single compounds (including sulfadiazine, sulfamethoxazole, ofloxacin, azithromycin and erythromycin-H2O) in effluent and sludge, as well as the mixture of the 21 detected PhACs in effluent, sludge and receiving water had a significant ecotoxicological risk to algae. Therefore, further control of PhACs in effluent and sludge is required before their discharge and application to prevent their introduction into the environment. PMID:24176710

Yan, Qing; Gao, Xu; Chen, You-Peng; Peng, Xu-Ya; Zhang, Yi-Xin; Gan, Xiu-Mei; Zi, Cheng-Fang; Guo, Jin-Song



Research on sludge-fly ash ceramic particles (SFCP) for synthetic and municipal wastewater treatment in biological aerated filter (BAF).  


Sludge-fly ash ceramic particles (SFCP) and clay ceramic particles (CCP) were employed in two lab-scale up-flow biological aerated filters (BAF) for wastewater treatment to investigate the availability of SFCP used as biofilm support compared with CCP. For synthetic wastewater, under the selected hydraulic retention times (HRT) of 1.5, 0.75 and 0.37 h, respectively, the removal efficiencies of chemical oxygen demand (COD(Cr)) and ammonium nitrogen (NH(4)(+)-N) in SFCP reactor were all higher than those of CCP reactor all through the media height. Moreover, better capabilities responding to loading shock and faster recovery after short intermittence were observed in the SFCP reactor compared with the CCP reactor. For municipal wastewater treatment, which was carried out under HRT of 0.75 h, air-liquid ratio of 7.5 and backwashing period of 48 h, the SFCP reactor also performed better than the CCP reactor, especially for the removal of NH(4)(+)-N. PMID:19540753

Zhao, Yaqin; Yue, Qinyan; Li, Renbo; Yue, Min; Han, Shuxin; Gao, Baoyu; Li, Qian; Yu, Hui



Particulate and colloidal silver in sewage effluent and sludge discharged from British wastewater treatment plants.  


Differential filtration was used to measure silver (>2 nm) entering and leaving nine sewage treatment plants (STPs). The mean concentration of colloidal (2-450 nm) silver, which includes nanosilver, was found to be 12 ng L(-1) in the influent and 6 ng L(-1) in the effluent. For particulate silver (>450 nm) the mean values were 3.3 ?g L(-1) for influent and 0.08 ?g L(-1) for effluent. Thus, removal was around 50% and 98% for colloidal and particulate silver respectively. There was no significant difference in performance between the different types of STP investigated (three examples each of activated sludge, biological filter and biological filter with tertiary treatment located across England, UK). In addition, treated sewage sludge samples (biosolids) were taken from several STPs to measure the total silver likely to be discharged to soils. Total silver was 3-14 mg kg(-1) DW in the sludge (median 3.6), which if the sludge were added at the recommended rate to soil, would add 11 ?g kg(-1) yr(-1) to the top 20 cm soil layer. Predicted concentrations using the LF2000-WQX model for all the rivers of England and Wales for nanosilver were typically in the 0-1 ng L(-1) range but levels up to 4 ng L(-1) are possible in a high discharge and low flow scenario. Predicted concentrations for the total particulate forms were mostly below 50 ng L(-1) except for a high discharge and low flow scenario where concentrations could reach 135 ng L(-1). PMID:25048887

Johnson, Andrew C; Jürgens, Monika D; Lawlor, Alan J; Cisowska, Iwona; Williams, Richard J



Structure and properties of noncrystalline nano-Al(OH)? reclaimed from carbonized residual wastewater treatment sludge.  


Performance of wastewater treatement sludge-carbon (SC) can be evidently improved by removing the inorganic fractions. A novel investigation for recovery of Al from acid leaching of SC and synthesis of nano-Al(OH)(3) has been conducted. Results show that the sodium aluminates with high purity can be obtained by effectively dissolving the inorganic fractions from SC and by further removing the impurities (Fe(3+), Ca(2+), Mg(2+), S(4+), and P(3+)). Highly dispersed Al(OH)(3) with high S(BET) is obtained at pH = 6. The peaks of -CH(2)- vibration and the C1s peaks (binding energies of 284.6 eV) imply that polyethylene glycol 1000 (PEG-1000) is chemically adsorbed on the surface of Al(OH)(3) samples, which is propitious to reduce the hydrogen bonds between water molecules and surface -OH groups to prevent hard agglomeration. The stretching vibration peaks of [AlO(2)](-) and the Na1s peaks confirm that a trace of sodium aluminate (NaAl(OH)(4), Na(+)(H(2)O)(4)[Al(OH)(4)(-)], or the dehydrated monomers) is retained in the prepared Al(OH)(3). The main phase transformation for calcination (?800 °C) of the SC-derived Al(OH)(3) is from amorphous Al(OH)(3) to amorphous A1(2)O(3). Here we highlight that production of Al(OH)(3) and SC from sludge provides the potential application in significant quantities that can revolutionize the handling of such kinds of harmful waste. PMID:22417744

Zou, Jinlong; Dai, Ying; Tian, Chungui; Pan, Kai; Jiang, Baojiang; Wang, Lei; Zhou, Wei; Tian, Guohui; Wang, Xue; Xing, Zipeng; Fu, Honggang



Examination of sludge accumulation rates and sludge characteristics for a decentralized community wastewater treatment systems with individual primary clarifier tanks located in Wardsville (Ontario, Canada).  


In conventional septic systems, settling and partial treatment via anaerobic digestion occurs in the septic tank. One of the byproducts of solids separation in the septic tank is a semi-liquid material known as septage, which must be periodically pumped out. Septage includes the liquid portion within the tank, as well as the sludge that settles at the bottom of the tank and the scum that floats to the surface of the liquid layer. A number of factors can influence septage characteristics, as well as the sludge and scum accumulation rates within the tank. This paper presents the results of a 2007 field sampling study conducted in Wardsville (Ontario, Canada). The field study examined 29 individual residential two-chamber septic tanks in a community serviced by a decentralized wastewater treatment system in operation for approximately 7 years without septage removal. The field investigation provided a comprehensive data set that allowed for statistical analysis of the data to assess the more critical factors influencing solids accumulation rates within each of the clarifier chambers. With this data, a number of predictive models were developed using water usage data for each residence as an explanatory variable. PMID:21123926

Lossing, Heather; Champagne, Pascale; McLellan, P James



A study of the relationship among sludge retention time, bacterial communities, and hydrolytic enzyme activities in inclined plate membrane bioreactors for the treatment of municipal wastewater.  


Inclined plate membrane bioreactors (ip-MBRs) have been proposed as a highly effective method in wastewater treatment. With the help of settling enhancer inclined plates, dense excess sludge can be kept in the mainstream of the process, and consequently, suitable sludge mass can be maintained in the membrane tank. In this study, the relationship among sludge retention time (SRT), bacterial communities, and hydrolytic enzyme activities was investigated. Two identical bench-scale ip-MBRs were operated 1 year in real municipal wastewater treatment. Multidimensional scaling (MDS) plots of terminal restriction fragment length polymorphism (T-RFLP) fingerprints showed similar changes in the bacterial communities in terms of bacterial members and abundance over time in both the reactors, which was primarily caused by the changes of wastewater composition. However, the impact of SRT revealed significant differences in the dominant bacterial communities when both the reactors were operated with a largely different SRT (infinite SRT and SRT of 20 days). The sequences of bacterial 16S rRNA gene were classified into six libraries of A-F. The largest group of sequences belonged to the phylum Proteobacteria. The phylum Bacteroidetes was dominant in the seed sludge retrieved from the conventional activated sludge (CAS) as Flavobacterium-like bacterium was dominantly observed. Under the MBR operation (libraries B-F), bacterial communities belonging to the phyla Proteobacteria and Chloroflexi were dominant. Most of them may be responsible for protein degradation because aminopeptidase activity increased in proportion with the abundance of these bacteria. PMID:25016344

Ittisupornrat, Suda; Tobino, Tomohiro; Yamamoto, Kazuo



Potential of filter-vermicomposter for household wastewater pre-treatment and sludge sanitisation on site.  


Septic tank systems have been widely used to separate and digest solid matter in the household wastewater for a long time. However, they contaminate groundwater with pathogens and nutrients and deprive agriculture of valuable nutrients and soil conditioner from human excreta. Compared with septic tank systems the filter-composter (Rottebehaelter), which usually consists of an underground monolithic concrete tank having two filter beds at its bottom or two filter bags that are hung side by side and used alternately at intervals of 6-12 months, is an efficient component for solid-liquid separation, pre-treatment and collection/storage of solid matter in household wastewater. The solids are retained and decompose in the filter bags or on the filter bed while the liquid filters through. However, because of the high moisture content of the retained solids decomposition is slow. Therefore, secondary treatment of the retained solids is required for sanitisation. The breakthrough was the combination of vermicomposting with the filter-composter system. Relatively dry and stable retained materials were obtained in the filter bags in about 3 months only. No secondary treatment is required as the human excreta will be converted to vermicastings, which are hygienically safe and can be reused as soil conditioner. Therefore, further development of the filter-composter with vermicomposting is worthwhile, especially the aspects of sanitisation of the faecal matter and its reuse as a soil conditioner. PMID:17506421

Gajurel, D; Deegener, S; Shalabi, M; Otterpohl, R



The re-use of Waste-Activated Sludge as part of a "zero-sludge" strategy for wastewater treatments in the pulp and paper industry.  


The possibility of introducing the thermo-alkali hydrolysis of Waste-Activated Sludge (WAS) was investigated, in order to enable the use of its solid residue as a raw material in cardboard production and the use of its liquid portion for anaerobic digestion in an UASB reactor. The evaluation of the hydrolysis at pH>12 and T=70°C showed that the microbe cells were disrupted with more than 90% efficiency in less than 2h. The solid portion was hygienised, therefore making it possible to integrate it into the cardboard production as a raw material for less demanding cardboards. Up to 6% addition of the liquid portion of hydrolysed WAS to wastewater decreased the specific biogas production in a pilot-scale UASB from 0.236 to 0.212 m(3)/kg(COD), while the efficiency of the COD removal decreased from 80.4% to 76.5%. These values still guarantee an adequate treatment of the wastewater and an increased biogas production by 16%. PMID:24215770

Kaluža, Leon; Suštarši?, Matej; Rutar, Vera; Zupan?i?, Gregor D



Metagenomic analysis on seasonal microbial variations of activated sludge from a full-scale wastewater treatment plant over 4 years.  


Metagenomic technique was employed to characterize the seasonal dynamics of activated sludge (AS) communities in a municipal wastewater treatment plant (WWTP) over 4 years. The results indicated that contrary to Eukaryota (mainly Rotifera and Nematoda), abundances of Bacteria and Archaea (mainly Euryarchaeota) were significantly higher in winter than summer. Two-way analysis of variance and canonical correspondence analysis revealed that many functionally important genera followed strong seasonal variation patterns driven by temperature and salinity gradients; among them, two nitrifying bacteria, Nitrospira and Nitrosomonas, displayed much higher abundances in summer, whereas phosphate-removing genus Tetrasphaera, denitrifier Paracoccus and potential human faecal bacteria, i.e. Bifidobacterium, Dorea and Ruminococcus, showed significantly higher abundances in winter. Particularly, occurrence of dual variation patterns beyond explanation merely by seasonality indicated that multivariables (e.g. dissolved oxygen, sludge retention time, nutrients) participated in shaping AS community structure. However, SEED subsystems annotation showed that functional categories in AS showed no significant difference between summer and winter, indicating that compared with its microbial components, the functional profiles of AS were much more stable. Taken together, our study provides novel insights into the microbial community variations in AS and discloses their correlations with influential factors in WWTPs. PMID:24596265

Ju, Feng; Guo, Feng; Ye, Lin; Xia, Yu; Zhang, Tong



[Amelioration effects of wastewater sludge biochars on red soil acidity and their environmental risk].  


Biochars were prepared from wastewater sludge from two wastewater treatment plants in Nanjing using a pyrolysis method at 300, 500 and 700 degrees C. The properties of the biochars were measured, and their amelioration effects on the acidity of a red soil and environmental risk of application of sludge biochars were examined to evaluate the possibility of agricultural application of wastewater sludge biochars in red soils. Results indicated that incorporation of both sludge and sludge biochar increased soil pH due to the alkalinity of sludge and sludge biochar, and the mineralization of organic N and nitrification of ammonium N from wastewater sludge induced soil pH fluctuated during incubation. The amelioration effects of biochars generated at 500 and 700 degrees C on the soil were significantly greater than that of sludge significantly. Sludge and sludge biochar contain ample base cations of Ca2+, Mg2+, K+ and Na+ and thus incorporation of sludge and sludge biochar increased the contents of soil exchangeable base cations and decreased soil exchangeable aluminum and H+. Contents of heavy metals in sludge biochars were greater than these in their feedstock sludge, while the contents of Cu, Pb, Ni and As in sludge biochars were lower than the standard values of heavy metals were wastewater sludge for agricultural use in acid soils in China except for Zn and Cd. The contents of available forms of heavy metals in the biochars generated from sludge from Chengdong wastewater treatment plant was lower than these in the corresponding sludge, suggesting that pyrolysis proceed decreased the activity of heavy metals in wastewater sludge. After 90-day incubation of the soil with sludge and sludge biochar, the differences in the contents of soil available heavy metals were not significant between the biochars and their feedstock sludge from Jiangxizhou wastewater treatment plant, and the contents in the treatments with biochars added was lower than these in the treatments with the corresponding sludge from Chengdong wastewater treatment plant for most of heavy metals. It can be concluded that the biochars from wastewater sludge could be used as soil amendments to adjust soil acidity. Application of sludge biochars did not increase activity and availability of heavy metals compared with direct incorporation of the sludge. PMID:23233992

Lu, Zai-Liang; Li, Jiu-Yu; Jiang, Jun; Xu, Ren-Kou



Basis for the development of sustainable optimisation indicators for activated sludge wastewater treatment plants in the Republic of Ireland.  


This paper describes the basis of a stakeholder-based sustainable optimisation indicator (SOI) system to be developed for small-to-medium sized activated sludge (AS) wastewater treatment plants (WwTPs) in the Republic of Ireland (ROI). Key technical publications relating to best practice plant operation, performance audits and optimisation, and indicator and benchmarking systems for wastewater services are identified. Optimisation studies were developed at a number of Irish AS WwTPs and key findings are presented. A national AS WwTP manager/operator survey was carried out to verify the applied operational findings and identify the key operator stakeholder requirements for this proposed SOI system. It was found that most plants require more consistent operational data-based decision-making, monitoring and communication structures to facilitate optimised, sustainable and continuous performance improvement. The applied optimisation and stakeholder consultation phases form the basis of the proposed stakeholder-based SOI system. This system will allow for continuous monitoring and rating of plant performance, facilitate optimised operation and encourage the prioritisation of performance improvement through tracking key operational metrics. Plant optimisation has become a major focus due to the transfer of all ROI water services to a national water utility from individual local authorities and the implementation of the EU Water Framework Directive. PMID:25607680

Gordon, G T; McCann, B P



Treatment of organic pollutants in coke plant wastewater by the method of ultrasonic irradiation, catalytic oxidation and activated sludge  

Microsoft Academic Search

The paper deals with the degradation of the organic pollutants in coke plant wastewater by the combination process of ultrasonic irradiation, catalytic oxidation and activated sludge. The effect factors of ultrasonic irradiation on the degradation of the organic pollutants such as saturating gas, initial pollutant concentration, ultrasonic power density, the category and consumption of catalyst were investigated. The results indicate

Ping Ning; Hans-Jörg Bart; Yijiao Jiang; A. de Haan; C. Tien



Use of dewatered alum sludge as main substrate in treatment reed bed receiving agricultural wastewater: Long-term trial  

Microsoft Academic Search

This study aims to explore a novel application of dewatered alum sludge cakes (DASC) as the main medium in a single model reed bed to treat phosphorus-rich animal farm wastewater under “tidal flow” operation on a long-term basis. It is expected that the cakes act as the carrier for developing biofilm and also serve as adsorbent to enhance phosphorus (P)

Y. Q. Zhao; X. H. Zhao; A. O. Babatunde



A combination of solvent extraction and freeze thaw for oil recovery from petroleum refinery wastewater treatment pond sludge.  


A combination of solvent extraction and freeze thaw was examined for recovering oil from the high-moisture petroleum refinery wastewater treatment pond sludge. Five solvents including cyclohexane (CHX), dichloromethane (DCM), methyl ethyl ketone (MEK), ethyl acetate (EA), and 2-propanol (2-Pro) were examined. It was found that these solvents except 2-Pro showed a promising oil recovery rate of about 40%, but the recycling of DCM solvent after oil extraction was quite low. Three solvents (CHX, MEK and EA) were then selected for examining the effect of freeze/thaw treatment on improving the quality of recovered oil. This treatment increased the total petroleum hydrocarbon (TPH) content in recovered oil from about 40% to 60% for both MEK and EA extractions, but little effect was observed for CHX extraction. Although the solid residue after oil recovery had a significantly decreased TPH content, a high concentration of heavy metals was observed, indicating that this residue may require proper management. In general, the combination of solvent extraction with freeze/thaw is effective for high-moisture oily hazardous waste treatment. PMID:25464326

Hu, Guangji; Li, Jianbing; Hou, Haobo



Pilot-scale test of an advanced, integrated wastewater treatment process with sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal (SIPER).  


Sludge reduction technologies are increasingly important in wastewater treatment, but have some defects. In order to remedy them, a novel, integrated process including sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal was developed. The pilot-scale system was operated steadily at a treatment scale of 10 m(3)/d for 90 days. The results showed excellent nutrient removal, with average removal efficiencies for NH4(+)-N, TN, TP, and COD reaching 98.2 ± 1.34%, 75.5 ± 3.46%, 95.3 ± 1.65%, and 92.7 ± 2.49%, respectively. The ratio of mixed liquor volatile suspended solids (MLVSS) to mixed liquor suspended solids (MLSS) in the system gradually increased, from 0.33 to 0.52. The process effectively prevented the accumulation of inert or inorganic solids in activated sludge. Phosphorus was recovered as a crystalline product with aluminum ion from wastewater. The observed sludge yield Yobs of the system was 0.103 gVSS/g COD, demonstrating that the system's sludge reduction potential is excellent. PMID:23751488

Yan, Peng; Ji, Fangying; Wang, Jing; Fan, Jianping; Guan, Wei; Chen, Qingkong



Sewage sludge management for phosphorus recovery as struvite in EBPR wastewater treatment plants.  


The influence of separate and mixed thickening of primary and secondary sludge on struvite recovery was studied. Phosphorus precipitation in the digester was reduced from 13.7 g of phosphorus per kg of treated sludge in the separate thickening experiment to 5.9 in the mixed thickening experiment. This lessening of the uncontrolled precipitation means a reduction of the operational problems and enhances the phosphorus availability for its later crystallization. High phosphorus precipitation and recovery efficiencies were achieved in both crystallization experiments. However, mixed thickening configuration showed a lower percentage of phosphorus precipitated as struvite due to the presence of high calcium concentrations. In spite of this low percentage, the global phosphorus mass balance showed that mixed thickening experiment produces a higher phosphorus recovery as struvite per kg of treated sludge (i.e., 3.6 gP/kg sludge vs. 2.5 gP/kg sludge in separate thickening). PMID:17976981

Pastor, L; Marti, N; Bouzas, A; Seco, A




EPA Science Inventory

Vermicomposting -- the biological degradation of organic matter that occurs as earthworms feed on waste materials -- has been advocated by some as a means of stabilizing and disposing of municipal wastewater sludges. Vermicomposting is being attempted on an experimental scale, th...


Integrating BES in the wastewater and sludge  

E-print Network

estimated that aeration in activated sludge systems may account for 1% of all electricity consumed in the US.g. by recirculating cathode effluent) and to equalize fluctuations in wastewater flow and strength. We have omitted

Angenent, Lars T.


Effect of sludge-fly ash ceramic particles (SFCP) on synthetic wastewater treatment in an A\\/O combined biological aerated filter  

Microsoft Academic Search

Novel media–sludge-fly ash ceramic particles (SFCP) employed in an upflow lab-scale A\\/O BAF were investigated for synthetic wastewater treatment. The influences of hydraulic retention time (HRT), air–liquid ratio (A\\/L) and recirculation on the removals of chemical oxygen demand (CODcr), ammonia (NH4+–N) and total nitrogen (TN) were discussed. The optimum operation conditions were obtained as HRT of 2.0h, A\\/L of 15:1

Shuxin Han; Qinyan Yue; Min Yue; Baoyu Gao; Yaqin Zhao; Wenjing Cheng



Combination of upflow anaerobic sludge blanket (UASB) reactor and partial nitritation/anammox moving bed biofilm reactor (MBBR) for municipal wastewater treatment.  


In this study the combination of an upflow anaerobic sludge blanket (UASB) reactor and a deammonification moving bed biofilm reactor (MBBR) for mainstream wastewater treatment was tested. The competition between aerobic ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) was studied during a 5months period of transition from reject water to mainstream wastewater followed by a 16months period of mainstream wastewater treatment. The decrease of influent ammonium concentration led to a wash-out of suspended biomass which had a major contribution to nitrite production. Influence of a dissolved oxygen concentration and a transient anoxia mechanism of NOB suppression were studied. It was shown that anoxic phase duration has no effect on NOB metabolism recovery and oxygen diffusion rather than affinities of AOB and NOB to oxygen determine the rate of nitrogen conversion in a biofilm system. Anammox activity remained on the level comparable to reject water treatment systems. PMID:25600011

Malovanyy, Andriy; Yang, Jingjing; Trela, Jozef; Plaza, Elzbieta




EPA Science Inventory

The objective of this paper is to discuss the acceptance of municipal wastewater sludge on land in the United States. Application to land has been an economical disposal method for cities and a means of increasing soil productivity. Use of land for sludge disposal is increasing. ...


Anaerobic granulation technology for wastewater treatment  

Microsoft Academic Search

Anaerobic wastewater treatment using granular sludge reactors is a developing technology, in which granular sludge is the core component. So far, around 900 anaerobic granular sludge units have been operated worldwide. Although intensive research attention has been given to anaerobic granules in the past 20 years, the mechanisms responsible for anaerobic granulation and the strategy of how to expedite substantially

Yu Liu; Hai-Lou Xu; Kuan-Yeow Show; Joo-Hwa Tay




E-print Network

. INTRODUCTION In Tunisia, the amount of sludge produced by wastewater treatment stations is constantly waste water treatment stations, in other words, most of it is wastewater from domestic sources. The second type is obtained from the treatment of industrial wastewater or partly from industrial wastewater

Boyer, Edmond


Preparation of ceramic filler from reusing sewage sludge and application in biological aerated filter for soy protein secondary wastewater treatment.  


Dehydrated sewage sludge (DSS) and clay used as raw materials for preparation of novel media-sludge ceramic filler (SCF) and SCF employed in a lab-scale up-flow biological aerated filter (BAF) were investigated for soy protein secondary wastewater treatment. Single factor experiments were designed to investigate the preparation of SCF, and the characteristics (microstructure properties, toxic metal leaching property and other physical properties) of SCF prepared under the optimum conditions were examined. The influences of media height, hydraulic retention time (HRT) and air-liquid ratio (A/L) on chemical oxygen demand (CODcr) and ammonia nitrogen (NH4(+)-N) removal rate were studied. The results showed that the optimum addition of DSS was approximately 25.0wt% according to the physical properties of SCF (expansion ratio of 53.0%, v/v, water absorption of 8.24wt%, bulk density of 350.4kgm(-3) and grain density of 931.5kgm(-3)), and the optimum conditions of BAF system were media height of 75.0cm, HRT of 10.0h and A/L of 15:1 in terms of CODcr and NH4(+)-N removal rate (91.02% and 90.48%, respectively). Additionally, CODcr and NH4(+)-N (81.6 and 15.3mgL(-1), respectively) in the final effluent of BAF system met the national standard (CODcr?100mgL(-1), NH4(+)-N?25.0mgL(-1), GB 18918-2002, secondary standard). PMID:25464302

Wu, Suqing; Qi, Yuanfeng; Yue, Qinyan; Gao, Baoyu; Gao, Yue; Fan, Chunzhen; He, Shengbing



Wastewater Treatment  

NSDL National Science Digital Library

Before this activity the students will have heard about groundwater and water resources through lecture to give them a background on where our drinking water comes from. The activity involves a tour of the local wastewater treatment plant where the students told about the treatment processes and shown the treatment facility. They are also introduced to the water quality testing done at the plans and they learn about the energy usage/management at the plant. As part of the activity they write up a paper on the processes in the treatment process from the time water enters the plant until it exits. The students are encouraged before hand to ask questions to ensure that they gather the needed information. This always means that each tour has a slightly different content based on these questions.

Bianca Pedersen


Interlaboratory study for the validation of an ecotoxicological procedure to monitor the quality of septic sludge received at a wastewater treatment plant.  


Septic tank sludge is regularly hauled to the Montreal Urban Community (MUC) wastewater treatment plant. It is then discharged and mixed with the wastewater inflow before entering the primary chemical treatment process. An ecotoxicological procedure integrating chemical and toxicological analyses has been recently developed and applied to screen for the illicit discharge of toxic substances in septic sludge. The toxicity tests used were the Microtox, the bacterial-respiration, and the lettuce (Lactuca sativa) root elongation tests. In order to validate the applicability of the proposed procedure, a two-year interlaboratory study was carried out. In general, the results obtained by two independent laboratories (MUC and the Centre d'expertise en analyse environnementale du Quebec) were comparable and reproducible. Some differences were found using the Microtox test. Organic (e.g., phenol and formaldehyde) and inorganic (e.g., nickel and cyanide) spiked septic sludge were detected with good reliability and high efficiency. The relative efficiency to detect spiked substances was > 70% and confirms the results of previous studies. In addition, the respiration test was the most efficient toxicological tool to detect spiked substances, whereas the Microtox was the least efficient (< 15%). Efficiencies to detect spiked contaminants were also similar for both laboratories. These results support previous data presented earlier and contribute to the validation of the ecotoxicological procedure used by the MUC to screen toxicity in septic sludge. PMID:11339716

Robidoux, P Y; Choucri, A; Bastien, C; Sunahara, G I; López-Gastey, J



Thermophilic aerobic biological wastewater treatment  

Microsoft Academic Search

The following review article will serve to elucidate the existing state-of-the-art and breadth of technical understanding related to thermophilic aerobic biological wastewater treatment. The advantages of this technology include rapid biodegradation rates, low sludge yields, and excellent process stability. Substrate utilization rates reported in the technical literature are 3–10 times greater than that observed with analogous mesophilic processes, and sludge

Timothy M LaPara; James E Alleman



Psychrophilic (6--15 {degree}C) high-rate anaerobic treatment of malting wastewater in a two-module expanded granular sludge bed system  

SciTech Connect

Psychrophilic (6--15 C) anaerobic treatment of malting wastewater was investigated. A two-module expanded granular sludge bed reactor system with a total volume of 140 dm{sup 3} was used to treat malting wastewater having a soluble and total chemical oxygen demand (COD) between 233 and 1778 mg dm{sup {minus}3} and between 317 and 4422 mg dm{sup {minus}3}, respectively. The removal efficiencies at 6 C were 47 and 71% of the soluble and volatile fatty acids (VFA) COD, at organic loading rates (OLR) ranging between 3.3 and 5.8 kg of COD m{sup {minus}3} day{sup {minus}1}. The removal efficiencies at 10--15 C were 67--78 and 90--96% of the soluble and VFA COD at an OLR between 2.8 and 12.3 kg of COD m{sup {minus}3} day{sup {minus}1}. The specific methanogenic activity of the sludge present in each module increased 2--3-fold during system operation for 400 days. The relatively high concentration of suspended solids in the influent (25% of the total COD) caused a deterioration of the sludge bed in the first reactor module. This was aggravated by excessive growth of acidifying biomass, which persisted in the first module sludge bed and resulted in granular sludge flotation. However, the second module could accommodate the increased OLR, this providing a very high effluent quality (soluble COD < 200 mg dm{sup {minus}3}) of the total system. The stability of module 1 concerning suspended solids could be restored by presettling the wastewater.

Rebac, S.; Lier, J.B. van; Lens, P.; Cappellen, J. van; Vermeulen, M.; Stams, A.J.M.; Lettinga, G. [Wageningen Agricultural Univ. (Netherlands)] [Wageningen Agricultural Univ. (Netherlands); Dekkers, F.; Swinkels, K.T.M. [Bavaria B.V., Lieshout (Netherlands)] [Bavaria B.V., Lieshout (Netherlands)



Heat inactivation of poliovirus in wastewater sludge.  

PubMed Central

The effect of raw and anaerobically digested sludge on heat inactivation of poliovirus was investigated. Raw sludge was found to be very protective of poliovirus plaque-forming ability at all temperatures studied, but digested sludge had variable effects that were highly dependent upon the experimental conditions. In low concentrations and at relatively low inactivation temperatures, digested sludge is nearly as protective of poliovirus as raw sludge. However, at higher tempeatures and concentrations, digested sludge caused a significant acceleration of poliovirus inactivation. The difference between the protective capability of raw and digested sludge is not due to loss of protective material, because this component is present in the solids of digested sludge as well as in those of raw sludge. Instead, the difference is due to a virucidal agent acquired during digestion. Addition of this agent to the solids of either raw or digested sludge reverses the protective potential of these solids during heat treatment of poliovirus. PMID:185956

Ward, R L; Ashley, C S; Moseley, R H



The effect of chemical composition on the PCT durability of mixed waste glasses from wastewater treatment sludges  

SciTech Connect

An experimental program has been designed to examine the chemical durability of glass compositions derived from the vitrification of simulated wastewater treatment sludges. These sludges represent the majority of low-level mixed wastes currently in need of treatment by the US DOE. The major oxides in these model glasses included SiO{sub 2}, Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Na{sub 2}O, CaO and Fe{sub 2}O{sub 3}. In addition, three minor oxides, BaO, NiO, and PbO, were added as hazardous metals. The major oxides were each varied at two levels resulting in 32 experimental glasses. The chemical durability was measured by the 7-Day Product Consistency Test (PCT). The normalized sodium release rates (NRR{sub Na}) of these glasses ranged from 0.01 to 4.99 g/m{sup 2}. The molar ratio of the glass-former to glass-modifier (F/M) was found to have the greatest effect on PCT durability. Glass-formers included SiO{sub 2}, Al{sub 2}O{sub 3}, and B{sub 2}O{sub 3}, while Na{sub 2}O, CaO, BaO, NiO, and PbO were glass-modifiers. As this ratio increased from 0.75 to 2.0, NRR{sub Na} was found to decrease between one and two orders of magnitude. Another important effect on NRR{sub Na} was the Na{sub 2}O/CaO ratio. As this ratio increased from 0.5 to 2.0, NRR{sub Na} increased up to two orders of magnitude for the glasses with the low F/M ratio but almost no effect was observed for the glasses with the high F/M ratio. Increasing the iron oxide content from 2 to 18 mole% was found to decrease NRR{sub Na} one order of magnitude for the glasses with low F/M but iron had little effect on the glasses with the high F/M ratio. The durability also increased when 10 mole percent Al{sub 2}O{sub 3} was included in low iron oxide glasses but no effect was observed with the high iron glasses. The addition of B{sub 2}O{sub 3} had little effect on durability. The effects of other composition parameters on durability are discussed as well.

Resce, J.L.; Ragsdale, R.G.; Overcamp, T.J. [Clemson Univ., SC (United States); Bickford, D.F.; Cicero, C.A. [Savannah River Technology Center, Aiken, SC (United States)



Hybrid process for heavy metal removal from wastewater sludge.  


Bioleaching processes have been demonstrated to be effective technologies in removing heavy metals from wastewater sludge, but long hydraulic retention times are typically required to operate these bioprocesses. A hybrid process (coupling biological and chemical processes) has been explored in laboratory pilot-scale experiments for heavy metals (cadmium [Cd], copper [Cu], chromium [Cr], and zinc [Zn]) removal from three types of sludge (primary sludge, secondary activated sludge, and a mixture of primary and secondary sludge). The hybrid process consisted of producing a concentrate ferric ion solution followed by chemical treatment of sludges. Ferric iron solution was produced biologically via oxidation of ferrous iron by A. ferrooxidans in a continuous-flow stirred tank (5.2 L) reactor (CSTR). Wastewater sludge filtrate (WSF) containing nutrients (phosphorus and nitrogen) has been used as culture media to support the growth and activity of indigenous iron-oxidizing bacteria. Results showed that total organic carbon (TOC) concentrations of the culture media in excess of 235 mg/L were found to be inhibitory to bacterial growth. The oxidation rate increased as ferrous iron concentrations ranged from 10 to 40 g Fe2+/L. The percentage of ferrous iron (Fe2+) oxidized to ferric iron (Fe3+) increased as the hydraulic retention time (HRT) increased from 12 to 48 h. Successful and complete Fe2+ oxidation was recorded at a HRT of 48 h using 10 g Fe2+/L. Subsequently, ferric ion solution produced by A. ferrooxidans in sludge filtrate was used to solubilize heavy metals contained in wastewater sludge. The best solubilization was obtained with a mixture of primary and secondary sludge, demonstrating a removal efficiency of 63, 71, 49, and 80% for Cd, Cu, Cr, and Zn, respectively. PMID:16121505

Drogui, Patrick; Blais, Jean-François; Mercier, Guy



Can those organic micro-pollutants that are recalcitrant in activated sludge treatment be removed from wastewater by biofilm reactors (slow sand filters)?  


The degradation of seven compounds which are usually recalcitrant in classical activated sludge treatment (e.g., diclofenac, propranolol, iopromide, iohexol, iomeprol tebuconazole and propiconazole) was studied in a biofilm reactor (slow sand filtration). This reactor was used to treat real effluent-wastewater at different flow rates (hydraulic loadings) under aerobic conditions so removal and degradation kinetics of these recalcitrant compounds were calculated. With the hydraulic loading rate of 0.012 m(3)m(2)h(-1) the reactor removed 41, 94, 58, 57 and 85% of diclofenac, propranolol, iopromide, iohexol and iomeprol respectively. For these compounds the removal efficiency was dependent on hydraulic residence-times. Only 59 and 21% of the incoming tebuconazole and propiconazole respectively were removed but their removal did not depend on hydraulic residence time. Biofilm reactors are thus efficient in removing micro-pollutants and could be considered as an option for advanced treatment in small wastewater treatment plants. PMID:25460965

Escolà Casas, Mònica; Bester, Kai



Recovery of volatile fatty acids from fermentation of sewage sludge in municipal wastewater treatment plants.  


This work investigated the pilot scale production of short chain fatty acids (SCFAs) from sewage sludge through alkaline fermentation and the subsequent membrane filtration. Furthermore, the impact of the fermentation liquid on nutrient bioremoval was examined. The addition of wollastonite in the fermenter to buffer the pH affected the composition of the carbon source produced during fermentation, resulting in higher COD/NH4-N and COD/PO4-P ratios in the liquid phase and higher content of propionic acid. The addition of wollastonite decreased the capillary suction time (CST) and the time to filter (TTF), resulting in favorable dewatering characteristics. The sludge dewatering characteristics and the separation process were adversely affected from the use of caustic soda. When wollastonite was added, the permeate flux increased by 32%, compared to the use of caustic soda. When fermentation liquid was added as carbon source for nutrient removal, higher removal rates were obtained compared to the use of acetic acid. PMID:25459853

Longo, S; Katsou, E; Malamis, S; Frison, N; Renzi, D; Fatone, F



Harvesting biogas from wastewater sludge and food waste  

NASA Astrophysics Data System (ADS)

Wastewater sludge and food waste are good source of biogas. Anaerobic treatment of slude and food waste able to produce biogas which is a potential renewable energy source. This study looks into the potential biogas generation and the effects of temperature on biogas generation. A lab scale reactor was used to simulate the biogas generation. The results show that wastewater sludge able to produced upto 44.82 ml biogas/kg of sludge. When mixed with food waste at a ratio of 30:70 (food waste), the biogas generated were 219.07 ml/kg of waste. Anaerobic of food waste alone produced biogas amount to 59.75 ml/kg of food waste. Anaerobic treatment also reduces the volume of waste. The effect of temperature shows that higher temperature produces more biogas than lower temperature.

Chua, K. H.; Cheah, W. L.; Tan, C. F.; Leong, Y. P.



Current levels and composition profiles of emerging halogenated flame retardants and dehalogenated products in sewage sludge from municipal wastewater treatment plants in China.  


Occurrence of new toxic chemicals in sludge from wastewater treatment plants (WWTPs) is of concern for the environment and human health. Alternative halogenated flame retardants (HFRs) are a group of potentially harmful organic contaminants in the environment. In this study, a nationwide survey was carried out to identify the occurrence of HFRs and their potential dehalogenated products in sewage sludge from 62 WWTPs in China. Of all 20 target chemicals analyzed, decabromodiphenyl ethane (DBDPE), hexabromocyclododecane (HBCD) and 1, 2-bis (2,4,6-tribromophenoxy)-ethane (BTBPE) were detected in all sludge samples, and the concentrations were in the range of 0.82-215, 0.09-65.8, and 0.10-2.26 ng g(-1) d.w., respectively. Dechlorane Plus (DP) was found in 60 of 62 samples, and the concentration ranged from nd-298 ng g(-1) with a mean of 18.9 ng g(-1) d.w. The anti-DP fractional abundance fanti (0.79) in the samples was much higher than the commercial DP composition (fanti=0.59), indicating a stereoselective degradation. Comparison with global sludge concentrations of HFRs indicate that China is at the medium pollution level in the world. Principal components analysis revealed that strong correlations existed between ln-transformed concentrations (natural logarithm) of the dominant BFRs and total organic carbon (TOC) as well as industrial wastewater proportion, influent volume and serving population. Significant linear relationships (R=0.360-0.893, p<0.01) were found among emerging brominated flame retardants (BFRs), suggesting their common commercial applications and release sources to the environment. Two kinds of dehalogenated products, pentabromocyclododecane (PBCD) and undecachloropentacyclooctadecadiene (Cl11-DP), derived from HBCD and DP, were also identified in sewage sludge for the first time. PMID:25286358

Zeng, Lixi; Yang, Ruiqiang; Zhang, Qinghua; Zhang, Haidong; Xiao, Ke; Zhang, Haiyan; Wang, Yawei; Lam, Paul K S; Jiang, Guibin



Changes of microbial characteristics of retained sludge during low-temperature operation of an EGSB reactor for low-strength wastewater treatment.  


In this study, a lab scale EGSB reactor was operated for 400 days to investigate the influence of temperature-decrease on the microbial characteristic of retained sludge. The EGSB reactor was started-up at 15 degrees C seeding with 20 degrees C-grown granular sludge. The influent COD of synthetic wastewater was set at 0.6-0.8 gCOD/L. The process-temperature was stepwise reduced from 15 degrees C to 5 degrees C during 400 days operation. Decrease of temperature of the reactor from 15 degrees C to 10 degrees C caused the decline of COD removal efficiency. However, continuous operation of the EGSB reactor led the efficient treatment of wastewater (70% of COD removal, 50% of methane recovery) at 10 degrees C. We confirmed that the both acetate-fed and hydrogen-fed methanogenic activities of retained sludge clearly increased under 15 to 20 degrees C. Changes of microbial profiles of methanogenic bacteria were analyzed by 16S rDNA-targeted DGGE analysis and cloning. It shows that genus Methanospirillum as hydrogen-utilizing methanogen proliferated due to low temperature operation of the reactor. On the other hand, genus Methanosaeta presented in abundance as acetoclastic-methanogen throughout the experiment. PMID:18235183

Syutsubo, K; Yoochatchaval, W; Yoshida, H; Nishiyama, K; Okawara, M; Sumino, H; Araki, N; Harada, H; Ohashi, A



Industrial flue gas desulfurization waste may offer an opportunity to facilitate SANI® application for significant sludge minimization in freshwater wastewater treatment.  


This paper reports an exploratory study on the use of a sulfite-rich industrial effluent to enable the integration of a sulfite-sulfide-sulfate cycle to the conventional carbon and nitrogen cycles in wastewater treatment to achieve sludge minimization through the non-sludge-producing Sulfate reduction, Autotrophic denitri?cation and Nitri?cation Integrated (SANI) process. A laboratory-scale sulfite reduction reactor was set up for treating sulfite-rich synthetic wastewater simulating the wastewater from industrial flue gas desulfurization (FGD) units. The results indicated that the sulfite reduction reactor can be started up within 11 d, which was much faster than that using sulfate. Thiosulfate was found to be the major sulfite reduction intermediate, accounting for about 30% of the total reduced sulfur in the reactor effluent, which may enable additional footprint reduction of the autotrophic denitrification reactor in the SANI process. This study indicated that it was possible to make use of the FGD effluent for applying the FGD-SANI process in treating freshwater-based sewage. PMID:23787323

Qian, J; Jiang, F; Chui, H K; van Loosdrecht, Mark C M; Chen, G H



Assessing the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units.  


Wastewater reuse can significantly reduce environmental pollution and save the water sources. The study selected Cheng-Ching Lake water treatment plant in southern Taiwan to discuss the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units. The treatment units of this plant include wastewater basin, sedimentation basin, sludge thickener and sludge dewatering facility. In this study, the treatment efficiency of SS and turbidity were 48.35-99.68% and 24.15-99.36%, respectively, showing the significant removal efficiency of the wastewater process. However, the removal efficiencies of NH(3)-N, total organic carbon (TOC) and chemical oxygen demand (COD) are limited by wastewater treatment processes. Because NH(3)-N, TOC and COD of the mixing supernatant and raw water are regulated raw water quality standards, supernatant reuse is feasible and workable during wastewater processes at this plant. Overall, analytical results indicated that supernatant reuse is feasible. PMID:17503196

Lou, Jie-Chung; Lin, Yung-Chang



Wastewater Treatment  


... amazing ability to cope with small amounts of water wastes and pollution, but it would be overwhelmed if we didn't treat the billions of gallons of wastewater and sewage produced every day before ... is used water. It includes substances such as human waste, food ...


Electricity generation using chocolate industry wastewater and its treatment in activated sludge based microbial fuel cell and analysis of developed microbial community in the anode chamber.  


Feasibility of using chocolate industry wastewater as a substrate for electricity generation using activated sludge as a source of microorganisms was investigated in two-chambered microbial fuel cell. The maximum current generated with membrane and salt bridge MFCs was 3.02 and 2.3 A/m(2), respectively, at 100 ohms external resistance, whereas the maximum current generated in glucose powered MFC was 3.1 A/m(2). The use of chocolate industry wastewater in cathode chamber was promising with 4.1 mA current output. Significant reduction in COD, BOD, total solids and total dissolved solids of wastewater by 75%, 65%, 68%, 50%, respectively, indicated effective wastewater treatment in batch experiments. The 16S rDNA analysis of anode biofilm and suspended cells revealed predominance of beta-Proteobacteria clones with 50.6% followed by unclassified bacteria (9.9%), alpha-Proteobacteria (9.1%), other Proteobacteria (9%), Planctomycetes (5.8%), Firmicutes (4.9%), Nitrospora (3.3%), Spirochaetes (3.3%), Bacteroides (2.4%) and gamma-Proteobacteria (0.8%). Diverse bacterial groups represented as members of the anode chamber community. PMID:19539465

Patil, Sunil A; Surakasi, Venkata Prasad; Koul, Sandeep; Ijmulwar, Shrikant; Vivek, Amar; Shouche, Y S; Kapadnis, B P



High-nitrate wastewater treatment in an expanded granular sludge bed reactor and microbial diversity using 454 pyrosequencing analysis.  


Denitrification of high concentration of nitrate wastewater was investigated in expanded granular sludge bed (EGSB) reactor with sodium acetate as the carbon source. The optimal parameters were achieved with C/N mole ratio of 2.0, liquid up-flow velocity (Vup) of 3.0 m/h and pH of 6.2-8.2. Complete denitrification can be achieved even with nitrate nitrogen concentration as high as 14000 mg/L. Furthermore, 454-pyrosequencing technology was used to analyze bacterial diversity. Results showed that a total of 5573 sequences were obtained which could be affiliated to 6 phylogenetic groups, including Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Chloroflexi and unclassified phylum. Proteobacteria (84.53%) was the dominant microbial population, followed by Firmicutes (13.24%) and Actinobacteria (0.38%). The dominate phylum was different from that in other anaerobic system. PMID:23500551

Liao, Runhua; Shen, Ke; Li, Ai-Min; Shi, Peng; Li, Yan; Shi, Qianqian; Wang, Zhu



Decolorization and treatment of Kokuto-shochu distillery wastewater by the combination treatment involving biodecolorization and biotreatment by Penicillium oxalicum d, physical decolorization by ozonation and treatment by activated sludge.  


Kokuto-shochu is a traditional Japanese distilled liquor made from brown sugar. Kokuto-shochu distillery wastewater (KDW) contains high concentrations of organic compounds and brown pigments (called molasses pigments) which are hardly decolorized by general biological wastewater treatment. A fungus, Penicillium oxalicum d, which we isolated in a previous study, decolorizes 47% of the color from KDW without the addition of any nutrients. P. oxalicum d decolorizes KDW by absorbing the pigments into its mycelia. Here we describe a KDW treatment system that combines biodecolorization and biotreatment by P. oxalicum d with treatment by activated sludge and physical decolorization by ozonation. Adding HClO to suppress bacterial growth and replacing fresh seed sludge at regular intervals helped to maintain the dominance and decolorization ability of P. oxalicum d. In a laboratory-scale demonstration, 48 cycles (12 days) achieved a decolorization ratio of 90% and removed more than 97% of dissolved organic carbon (DOC), dissolved total nitrogen (DTN) and dissolved total phosphorus (DTP). A major feature of our system is that it uses only 6% of the water used in an activated sludge-ozonation system. PMID:20473555

Watanabe, Takashi; Tanaka, Miki; Masaki, Kazuo; Fujii, Tsutomu; Iefuji, Haruyuki



Polyhydroxyalkanoates (PHA) production using wastewater as carbon source and activated sludge as microorganisms.  


Activated sludge from different full-scale wastewater treatment plants (municipal, pulp and paper industry, starch manufacturing and cheese manufacturing wastewaters) was used as a source of microorganisms to produce biodegradable plastics in shake flask experiments. Acetate, glucose and different wastewaters were used as carbon sources. Pulp and paper wastewater sludge was found to accumulate maximum concentration (43% of dry weight of suspended solids) of polyhydroxy alkanoates (PHA) with acetate as carbon source. Among the different wastewaters tested as a source of carbon, pulp and paper industry and starch industry wastewaters were found to be the best source of carbon while employing pulp and paper activated sludge for maximum accumulation of PHA. High concentration of volatile fatty acids in these wastewaters was the probable reason. PMID:16749455

Yan, S; Tyagi, R D; Surampalli, R Y



Impact of ozone pre-treatment on the performance of upflow anaerobic sludge blanket treating pre-treated grain distillery wastewater.  


Two 2 L laboratory-scale upflow anaerobic sludge blanket (UASB) reactors were operated for 277 days. The substrate of the control reactor (Rc) contained grain distillery wastewater (GDWW) that had undergone coagulant pre-treatment, and the substrate of the second UASB reactor consisted of GDWW that had undergone coagulant pre-treatment and ozone pre-treatment (Ro). Both reactors treated pre-treated GDWW successfully at ca. 9 kgCOD m(-3) d(-1). Chemical oxygen demand (COD) reductions of ca. 96% for Rc and 93% for Ro were achieved. Fats, oils and grease (FOG) reductions (%) showed variations throughout the study, and reductions of ca. 88 and 92% were achieved for Rc and Ro, respectively. Rc produced more biogas, and the methane percentage was similar in both reactors. UASB granule washout in Rc suggested possible toxicity of unsaturated fatty acids present in non-ozonated substrate. The feasibility of FOG removal was demonstrated as both reactors successfully treated pre-treated GDWW. Better results were obtained for Ro effluent during post-ozonation. The ozone pre-treatment possibly led to easier degradable wastewater, and better results could potentially be obtained when other post-treatment steps are applied. Ozone pre-treatment did not, however, show an added benefit in the reactor performance results. PMID:25429461

Robertson, L; Britz, T J; Sigge, G O



Evaluating sedimentation problems in activated sludge treatment plants operating at complete sludge retention time.  


Zero net sludge growth can be achieved by complete retention of solids in activated sludge wastewater treatment, especially in high strength and biodegradable wastewaters. When increasing the solids retention time, MLSS and MLVSS concentrations reach a plateau phase and observed growth yields values tend to zero (Yobs ? 0). In this work, in order to evaluate sedimentation problems arised due to high MLSS concentrations and complete sludge retention operational conditions, two identical innovative slaughterhouse wastewater treatment plants were studied. Measurements of wastewaters' quality characteristics, treatment plant's operational conditions, sludge microscopic analysis and state point analysis were conducted. Results have shown that low COD/Nitrogen ratios increase sludge bulking and flotation phenomena due to accidental denitrification in clarifiers. High return activated sludge rate is essential in complete retention systems as it reduces sludge condensation and hydraulic retention time in the clarifiers. Under certain operational conditions sludge loading rates can greatly exceed literature limit values. The presented methodology is a useful tool for estimation of sedimentation problems encountered in activated sludge wastewater treatment plants with complete retention time. PMID:25463928

Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Pekridis, George; Taousanidis, Nikolaos



Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor  

Microsoft Academic Search

The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor\\u000a and a moving bed biofilm reactor (MBBR) at a temperature of (22–35 °C) was evaluated. The entire treatment system was operated\\u000a at different hydraulic retention times (HRT’s) of 13.3, 10 and 5.0 h. An overall reduction of 80–86% for CODtotal; 51–73% for CODcolloidal and 20–55%

A. Tawfik; F. El-Gohary; H. Temmink



Increased biogas production at wastewater treatment plants through co-digestion of sewage sludge with grease trap sludge from a meat processing plant  

Microsoft Academic Search

The feasibility of co-digesting grease trap sludge from a meat-processing plant and sewage sludge was studied in batch and reactor experiments at 35°C. Grease trap sludge had high methane production potential (918m3\\/tVSadded), but methane production started slowly. When mixed with sewage sludge, methane production started immediately and the potential increased with increasing grease trap sludge content. Semi-continuous co-digestion of the

S. Luostarinen; S. Luste; M. Sillanpää



Sludge treatment studies  

SciTech Connect

Solid formation in filtered leachates and wash solutions was seen in five of the six sludges treated by Enhanced Sludge Washing. Solid formation in process solutions takes a variety of forms: very fine particles, larger particulate solids, solids floating in solution like egg whites, gels, crystals, and coatings on sample containers. A gel-like material that formed in a filtered leachate from Enhanced Sludge Washing of Hanford T-104 sludge was identified as natrophosphate, Na{sub 7}(PO{sub 4}){sub 2}F{center_dot}19H{sub 2}O. A particulate material that formed in a filtered caustic leachate from Hanford SX-113 sludge contained sodium and silicon. This could be any of a host of sodium silicates in the NaOH-SiO{sub 2}-H{sub 2}O system. Acidic treatment of Hanford B-202 sludge with 1 M, 3 M, and 6 M HNO{sub 3} sequential leaching resulted in complete dissolution at 75 C, but not at ambient temperature. This treatment resulted in the formation of solids in filtered leachates. Analyses of the solids revealed that a gel material contained silica with some potassium, calcium, iron, and manganese. Two phases were embedded in the gel. One was barium sulfate. The other could not be identified, but it was determined that the only metal it contained was bismuth.

Beahm, E.C.; Weber, C.F.; Dillow, T.A.; Bush, S.A.; Lee, S.Y.; Hunt, R.D.




EPA Science Inventory

Fecal matter potentially containing pathogenic microorganisms and chemical contaminants enters community wastewater collection systems from hospitals, funeral homes, animal slaughtering operations, and dwellings. While these wastewaters are cleansed in the wastewater treatment p...



Microsoft Academic Search

The purpose of this study is to investigate the application of chemical conditioning method for the post-electroflocculation wastewater sludge treatment with polyelectrolytes of varying ionic characters, namely anionic, cationic and nonionic flocculating agents. Electroflocculation, a combination of the processes of electroflotation and electroprecipitation, was found effective to remove the organic and color components in monosodium glutamate fermentation wastewater. The settleability

Wen-Jang Chen; Tson-Nan Chen; Yang-Chu Cheng



Challenge of psychrophilic anaerobic wastewater treatment  

Microsoft Academic Search

Psychrophilic anaerobic treatment is an attractive option for wastewaters that are discharged at moderate to low temperature. The expanded granular sludge bed (EGSB) reactor has been shown to be a feasible system for anaerobic treatment of mainly soluble and pre-acidified wastewater at temperatures of 5–10°C. An organic loading rate (OLR) of 10–12 kg chemical oxygen demand (COD) per cubic meter

Gatze Lettinga; Salih Rebac; Grietje Zeeman



Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor.  


The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for COD(total); 51-73% for COD(colloidal) and 20-55% for COD(soluble) was found at a total HRT of 5-10 h, respectively. By prolonging the HRT to 13.3 h, the removal efficiencies of COD(total), COD(colloidal) and COD(soluble) increased up to 92, 89 and 80%, respectively. However, the removal efficiency of COD(suspended) in the combined system remained unaffected when increasing the total HRT from 5 to 10 h and from 10 to 13.3 h. This indicates that, the removal of COD(suspended) was independent on the imposed HRT. Ammonia-nitrogen removal in MBBR treating UASB reactor effluent was significantly influenced by organic loading rate (OLR). 62% of ammonia was eliminated at OLR of 4.6 g COD m(-2) day(-1). The removal efficiency was decreased by a value of 34 and 43% at a higher OLR's of 7.4 and 17.8 g COD m(-2) day(-1), respectively. The mean overall residual counts of faecal coliform in the final effluent were 8.9 x 10(4) MPN per 100 ml at a HRT of 13.3 h, 4.9 x 10(5) MPN per 100 ml at a HRT of 10 h and 9.4 x 10(5) MPN per 100 ml at a HRT of 5.0 h, corresponding to overall log(10) reduction of 2.3, 1.4 and 0.7, respectively. The discharged sludge from UASB-MBBR exerts an excellent settling property. Moreover, the mean value of the net sludge yield was only 6% in UASB reactor and 7% in the MBBR of the total influent COD at a total HRT of 13.3 h. Accordingly, the use of the combined UASB-MBBR system for sewage treatment is recommended at a total HRT of 13.3 h. PMID:19404682

Tawfik, A; El-Gohary, F; Temmink, H



Microbial community structure and population dynamics of granules developed in expanded granular sludge bed (EGSB) reactors for the anaerobic treatment of low-strength wastewater at low temperature.  


The anaerobic biological treatment of sucrose-based, low-strength wastewater was investigated in expanded granular sludge bed (EGSB) reactors at low temperatures over a 300-day trial period. During the trial, the operating temperature was lowered in a stepwise manner from 20 degrees C to 5 degrees C. As a result, the reactors exhibited sufficient performances until 10 degrees C operation. The COD removal rate was 3.1-3.8 kgCOD m(-3) day(-1) at 10 degrees C. In particular, the COD removal rate increased gradually through the low-temperature operation; indeed, the later stages of the 10 degrees C operation attained a rate similar to those achieved at 20 degrees C and 15 degrees C. This finding is especially practical for applications of psychrophilic methane fermentation. Additionally, the structure of the microbial community in the granular sludge was analyzed by clone analysis based on 16S rRNA genes and fluorescence in situ hybridization (FISH). As a result, the percentage of the phylum Firmicutes, which were assumed to be Anaerobivrio sp. and Lactococcus sp., greatly increased from 0.7% to 8.0% of the total cells, especially in the surface layer of the granular sludge. These bacteria would contribute to the degradation of the sucrose substrate anaerobically at ambient temperatures. Moreover, the results suggest that a Methanospirillum species, which is a H2-utilizing methanogen, increased from 0.5% to 6.7% during the low-temperature incubation, with a significant increase of methanogenic activity from H2/CO2 at 20 degrees C. Thus, the Methanospirillum species detected in this study may have a key role as hydrogen scavenger during hydrogen-metabolism in low-temperature conditions. PMID:20390923

Tsushima, Ikuo; Yoochatchaval, Wilasinee; Yoshida, Hiroki; Araki, Nobuo; Syutsubo, Kazuaki




EPA Science Inventory

This two volume set presents in detail technical design information for the following sludge treatment and disposal processes: lime stabilization, anaerobic digestion, aerobic digestion, thermal sludge conditioning, thickening, dewatering, and landfilling. The discussion of each ...


Wastewater treatment with particulate biofilm reactors  

Microsoft Academic Search

The review presented in this paper focuses on applications of particulate biofilm reactors (e.g. Upflow Sludge Blanket, Biofilm Fluidized Bed, Expanded Granular Sludge Blanket, Biofilm Airlift Suspension, Internal Circulation reactors). Several full-scale applications for municipal and industrial wastewater treatment are presented and illustrated, and their most important design and operation aspects (e.g. biofilm formation, hydrodynamics, mass transfer, mixing) are analysed

C. Nicolella; M. C. M. van Loosdrecht; J. J. Heijnen



Wastewater treatment plant cogeneration options  

SciTech Connect

This paper reviews municipal sewage cogeneration and digester gas utilization options available to wastewater treatment plants, and will focus on utilizing the digester gas in combustion turbines and engine-generator systems. Defining the digestion and gas generation process is crucial to understanding the best gas utilization system. In municipal wastewater treatment plants biosolids (sludge) reduction is accomplished using aerobic or anaerobic digestion. The basic process of treating sewage solids with digestion is not new and has been practiced as far back as the nineteenth century. High energy usage consumed by aerobic blow systems supplying air to the process and the potential ``free`` energy generated by anaerobic digesters sometimes sways designers to select anaerobic over aerobic digestion. The following areas will be covered in this paper: gas utilization and cogeneration; definition of digestion process; sizing the cogeneration system and reviewing the systems components; emissions requirements and options; and capital, and O and M cost analysis.

Stringfield, J.G. [Black and Veatch, Kansas City, MO (United States)



Destruction and formation of PCDD/Fs in a fluidised bed combustor co-incinerating automotive shredder residue with refuse derived fuel and wastewater treatment sludge.  


During an eight day trial automotive shredder residue (ASR) was added to the usual waste feed of a Fluidized Bed Combustor (FBC) for waste-to-energy conversion; the input waste mix consisted of 25% ASR, 25% refuse-derived fuel (RDF) and 50% wastewater treatment (WWT) sludge. All inputs and outputs were sampled and the concentration of the 17 PCDD/Fs with TEF-values was determined in order to obtain "PCDD/F fingerprints". The ASR contained approximately 9000 ng PCDD/Fs/kg(DW), six times more than the RDF and 10 times more than the WWT sludge. The fingerprint of ASR and RDF was dominated by HpCDD and OCDD, which accounted for 90% of the total PDDD/F content, whereas the WWT sludge contained relatively more HpCDFs and OCDF (together 70%). The flue gas cleaning residue (FGCR) and fly and boiler ash contained approximately 30,000 and 2500 ng PCDD/Fs/kg(DW), respectively. The fingerprints of these outputs were also dominated by HpCDFs and OCDF. The bottom ash contained only OCDD and OCDF, in total 8 ng PCDD/Fs/kg (DW). From the comparison of the bottom ash fingerprints with the fingerprints of the other output fractions and of the inputs, it could be concluded that the PCDD/Fs in the waste were destroyed and new PCDD/Fs were formed in the post combustion process by de novo synthesis. During the ASR-co-incineration, the PCDD/F congener concentrations in the fly and boiler ash, FGCR and flue gas were 1.25-10 times higher compared to the same output fractions generated during incineration of the usual waste mix (70% RDF and 30% WWT sludge). The concentration of the higher chlorinated PCDD/Fs increased most. As these congeners have the lowest TEF-factors, the total PCDD/F output, expressed in kg TEQ/year, of the FBC did not increase significantly when ASR was co-incinerated. Due to the relatively high copper levels in the ASR, the copper concentrations in the FBCs outputs increased. As copper catalysis the de novo syntheses, this could explain the increase in PCDD/F concentrations in these outputs. PMID:21621915

Van Caneghem, J; Vermeulen, I; Block, C; Van Brecht, A; Van Royen, P; Jaspers, M; Wauters, G; Vandecasteele, C



Mechanisms of Cu2+ migration, recovery and detoxification in Cu2+-, SO4(2-) -containing wastewater treatment process with anaerobic granular sludge.  


In this study, anaerobic granular sludge with sulphate-reducing bacteria (SRB) was applied to treat Cu2+-, SO4(2-) -containing wastewater in an expanded granular sludge bed reactor. The migration and enrichment of copper in anaerobic granular sludge were envaluated. By analysing the sludge with X-ray diffraction, copper was determined to be present as covellite (CuS) in the sludge. Observations at the microscopic level showed that CuS precipitates were absorbed onto granules and gradually migrated from the outer to the interior layer of the granule over time and finally accumulated in the core of the granular sludge. Because of the migration of the CuS precipitates and the protection of the extracellular polymeric substances matrix, SRB were able to tolerate copper concentrations up to 10 mg/L. A copper removal efficiency of about 96% was observed at a steady state for 3 months, and copper was enriched in the granular sludge. PMID:24956789

Cao, Xiaolei; Cao, Hongbin; Sheng, Yuxing; Xie, Yongbing; Zhang, Kai; Zhang, Yi; Crittenden, John C




EPA Science Inventory

The paper summarizes findings of a 10-week pilot plant study of gray iron foundry wastewater treatment. Treatment technologies studied included lime softening, lime/soda ash softening, polymer addition, flocculation/sedimentation, and dual media filtration. Results indicate that ...


The sludge loading rate regulates the growth and release of heterotrophic bacteria resistant to six types of antibiotics in wastewater activated sludge.  


Wastewater treatment plants are considered as hot reservoirs of antimicrobial resistance. However, the fates of antibiotic-resistant bacteria during biological treatment processes and relevant influencing factors have not been fully understood. This study evaluated the effects of the sludge loading rate on the growth and release of six kinds of antibiotic-resistant bacteria in an activated sludge system. The results indicated that higher sludge loading rates amplified the growth of all six types of antibiotic resistant bacteria. The release of most antibiotic-resistant bacteria through both the effluent and biosolids was amplified with increased sludge loading rate. Biosolids were the main pattern for all antibiotic-resistant bacteria release in an activated sludge system, which was determined primarily by their growth in the activated sludge. A higher sludge loading rate reactor tended to retain more antibiotic resistance. An activated sludge system with lower sludge loading rates was considered more conducive to the control of antibiotic resistance. PMID:25502931

Yuan, Qing-Bin; Guo, Mei-Ting; Yang, Jian




EPA Science Inventory

Metals removal and partitioning to primary and secondary sludge during treatment of domestic wastewater by conventional sewage treatment processes was studied. Raw wastewater entering the Mill Creek Sewage Treatment Plant, Cincinnati, Ohio, was fed to a 0.1 l/s (1.6 gpm) pilot tr...


Microwave, ultrasonic and chemo-mechanical pretreatments for enhancing methane potential of pulp mill wastewater treatment sludge.  


Microwave (2450 MHz, 1250 W), ultrasonic (20 kHz, 400 W) and chemo-mechanical (MicroSludge® with 900 mg/L NaOH followed by 83,000 kPa) pretreatments were applied to pulp mill waste sludge to enhance methane production and reduce digester sludge retention time. The effects of four variables (microwave temperature in a range of 50-175°C) and sonication time (15-90 min), sludge type (primary or secondary) and digester temperature (mesophilic and thermophilic) were investigated. Microwave pretreatment proved to be the most effective, increasing specific methane yields of WAS samples by 90% compared to controls after 21 days of mesophilic digestion. Sonication solubilized the sludge samples better, but resulted in soluble non-biodegradable compounds. Based on the laboratory scale data, MicroSludge® was found the least energy intensive pretreatment followed by sonication for 15 min alternative with net energy profits of 1366 and 386 kWh/tonne of total solids (TS), respectively. Pretreatment benefits were smaller for thermophilic digesters. PMID:21727004

Saha, Mithun; Eskicioglu, Cigdem; Marin, Juan




EPA Science Inventory

Data obtained as part of a comprehensive community health study conducted during 1965-1971 were utilized to examine the incidence of acute illness in a population surrounding an activated sludge wastewater treatment plant and a control location in Tecumseh, Michigan. Study partic...


Psychrophilic anaerobic treatment of low strength wastewaters  

Microsoft Academic Search

Psychrophilic (2 to 20°C) anaerobic treatment of low strength synthetic and malting wastewater was investigated using a single and hvo module expanded granular sludge bed (EGSB) reactor system. The chemical oxygen demand (COD) removal efftciencies found in the experiments exceeded 90% in the single module reactor at an organic loading rate up to 12g COD dm?3’ day?1 and a HRT

Salih Rebac; Jules B. van Lier; Piet Lens; Alfons J. M. Stams; Freddy Dekkers; Koen Th. M. Swinkels; Gatze Lettinga



Membrane fouling in an anaerobic dynamic membrane bioreactor (AnDMBR) for municipal wastewater treatment: Characteristics of membrane foulants and bulk sludge  

Microsoft Academic Search

An anaerobic dynamic membrane bioreactor (AnDMBR) treating municipal wastewater with a high flux of 65L\\/(m2h) was operated for 11 months. Organic and inorganic membrane foulants and bulk sludge characteristics were investigated using particle size distribution analyzer, three-dimensional excitation–emission matrix fluorescence spectroscopy and X-ray fluorescence analysis. The fouling layers exhibited a double-layered structure, i.e., a loosely bound outer layer and a

Xinying Zhang; Zhiwei Wang; Zhichao Wu; Tianye Wei; Fenghai Lu; Jun Tong; Suihai Mai



Anaerobic treatment of domestic wastewater in a membrane-coupled expended granular sludge bed (EGSB) reactor under moderate to low temperature  

Microsoft Academic Search

The performance of an expended granular sludge bed (EGSB) reactor coupled with hollow fibre membrane filtration for treating domestic wastewater was monitored during 7-month period in the range 11–25°C, and at the hydraulic retention time (HRT) of 3.5 to 5.7h. With temperatures above 15°C, the system was capable of removing 85–96% of total chemical oxygen demand (COD) and 83–94% of

Li-Bing Chu; Feng-Lin Yang; Xing-Wen Zhang



Including the effects of filamentous bulking sludge during the simulation of wastewater treatment plants using a risk assessment model.  


The main objective of this paper is to demonstrate how including the occurrence of filamentous bulking sludge in a secondary clarifier model will affect the predicted process performance during the simulation of WWTPs. The IWA Benchmark Simulation Model No. 2 (BSM2) is hereby used as a simulation case study. Practically, the proposed approach includes a risk assessment model based on a knowledge-based decision tree to detect favourable conditions for the development of filamentous bulking sludge. Once such conditions are detected, the settling characteristics of the secondary clarifier model are automatically changed during the simulation by modifying the settling model parameters to mimic the effect of growth of filamentous bacteria. The simulation results demonstrate that including effects of filamentous bulking in the secondary clarifier model results in a more realistic plant performance. Particularly, during the periods when the conditions for the development of filamentous bulking sludge are favourable--leading to poor activated sludge compaction, low return and waste TSS concentrations and difficulties in maintaining the biomass in the aeration basins--a subsequent reduction in overall pollution removal efficiency is observed. Also, a scenario analysis is conducted to examine i) the influence of sludge retention time (SRT), the external recirculation flow rate (Q(r)) and the air flow rate in the bioreactor (modelled as k(L)a) as factors promoting bulking sludge, and ii) the effect on the model predictions when the settling properties are changed due to a possible proliferation of filamentous microorganisms. Finally, the potentially adverse effects of certain operational procedures are highlighted, since such effects are normally not considered by state-of-the-art models that do not include microbiology-related solids separation problems. PMID:19695661

Flores-Alsina, Xavier; Comas, Joaquim; Rodriguez-Roda, Ignasi; Gernaey, Krist V; Rosen, Christian




EPA Science Inventory

Municipal wastewater sludges frequently contain undesirably high concentrations of heavy metals and/or organic pollutants which interfere with beneficial use of sludge on farmland and with some disposal practices such as ocean disposal. Centrifugal classification is a low-cost pr...


Genotoxicity testing of wastewater sludge using the Allium cepa anaphase-telophase chromosome aberration assay.  


Wastewater sludges were analysed in the Allium cepa genotoxicity test. They were sampled during three winter periods from three Danish municipal wastewater treatment plants differing in size and industrial load. The toxicity of the sludge was tested in the Allium root inhibition assay, and the results expressed as EC30 and EC50 values showed that the toxicity could be positive correlated to the industrial load. However, when genotoxicity was tested at concentrations corresponding to the EC30 and EC50 values in the A. cepa anaphase-telophase assay, only two sludge samples from the smallest plant with the lowest industrial load induced significant chromosome aberrations. Concentrations of the heavy metal's Pb, Ni, Cr, Zn, Cu, and Cd were also determined and could partly be correlated with the toxicity of the sludge and the industrial load of the treatment plants. PMID:9757013

Rank, J; Nielsen, M H



Utilization of AMD sludges from the anthracite region of Pennsylvania for removal of phosphorus from wastewater  

USGS Publications Warehouse

Excess phosphorus (P) inputs from human sewage, animal feeding operations, and nonpoint source discharges to the environment have resulted in the eutrophication of sensitive receiving bodies of water such as the Great Lakes and Chesapeake Bay. Phosphorus loads in wastewater discharged from such sources can be decreased by conventional treatment with iron and aluminum salts but these chemical reagents are expensive or impractical for many applications. Acid mine drainage (AMD) sludges are an inexpensive source of iron and aluminum hydrous oxides that could offer an attractive alternative to chemical reagent dosing for the removal of P from local wastewater. Previous investigations have focused on AMD sludges generated in the bituminous coal region of western Pennsylvania, and confirmed that some of those sludges are good sorbents for P over a wide range of operating conditions. In this study, we sampled sludges produced by AMD treatment at six different sites in the anthracite region of Pennsylvania for potential use as P sequestration sorbents. Sludge samples were dried, characterized, and then tested for P removal from water. In addition, the concentrations of acid-extractable metals and other impurities were investigated. Test results revealed that sludges from four of the sites showed good P sorption and were unlikely to add contaminants to treated water. These results indicate that AMD sludges could be beneficially used to sequester P from the environment, while at the same time decreasing the expense of sludge disposal.

Sibrell, P.L.; Cravotta, C.A., III; Lehman, W.G.; Reichert, W.



Removal of phosphorus from agricultural wastewaters using adsorption media prepared from acid mine drainage sludge  

USGS Publications Warehouse

Excess phosphorus in wastewaters promotes eutrophication in receiving waterways. A??cost-effective method for the removal of phosphorus from water would significantly reduce the impact of such wastewaters on the environment. Acid mine drainage sludge is a waste product produced by the neutralization of acid mine drainage, and consists mainly of the same metal hydroxides used in traditional wastewater treatment for the removal of phosphorus. In this paper, we describe a method for the drying and pelletization of acid mine drainage sludge that results in a particulate media, which we have termed Ferroxysorb, for the removal of phosphorus from wastewater in an efficient packed bed contactor. Adsorption capacities are high, and kinetics rapid, such that a contact time of less than 5 min is sufficient for removal of 60-90% of the phosphorus, depending on the feed concentration and time in service. In addition, the adsorption capacity of the Ferroxysorb media was increased dramatically by using two columns in an alternating sequence so that each sludge bed receives alternating rest and adsorption cycles. A stripping procedure based on treatment with dilute sodium hydroxide was also developed that allows for recovery of the P from the media, with the possibility of generating a marketable fertilizer product. These results indicate that acid mine drainage sludges - hitherto thought of as undesirable wastes - can be used to remove phosphorus from wastewater, thus offsetting a portion of acid mine drainage treatment costs while at the same time improving water quality in sensitive watersheds.

Sibrell, Philip L.; Montgomery, Gary A.; Ritenour, Kelsey L.; Tucker, Travis W.



Pretreatment of petrochemical wastewater by coagulation and flocculation and the sludge characteristics.  


In the present study, coagulation-flocculation was investigated as a pretreatment process for the treatment of purified terephthalic acid (PTA) wastewater. The effect of various inorganic and organic coagulants on the treatment of wastewater collected from flow equalization tank of an effluent treatment plant was studied. The settling and filtration characteristics of the sludge were also studied. The jar tests revealed that the wastewater was best treated when 3000 mg l(-1) of ferric chloride was dosed at pH 5.6. At optimum conditions, COD of the wastewater was reduced by 75.5%. The results of the gravity filtration of the treated wastewater showed that the addition of cationic polyacrylamide (175 mg l(-1)) to ferric chloride coagulation improved the filtration characteristics and reduced the specific cake resistance. Scanning electron microscopy and energy dispersive spectroscopy studies were also conducted to know the sludge structure and composition, respectively. Thermal analysis of the sludge showed that the oxidation of the sludges in the present study is a three step process. However, with the addition of C-PAA to ferric chloride coagulation system, the oxidation was found to be a two step process. PMID:20303661

Verma, Shilpi; Prasad, Basheshwar; Mishra, Indra Mani



Determination of 4'-isobutylacetophenone and other transformation products of anti-inflammatory drugs in water and sludge from five wastewater treatment plants in Sweden by hollow fiber liquid phase microextraction and gas chromatography-mass spectrometry.  


This work describes the development of a two-phase hollow fiber liquid phase microextraction method for the determination of three hydrophobic transformation products of the nonsteroidal anti-inflammatory drugs ketoprofen, ibuprofen and diclofenac: 3-acetobenzophenone, 4´-isobutylacetophenone and diclofenac amide. The optimized method involved extraction for 180 min at a stirring speed of 440 rpm. Hollow fibers (0.6mm i.d.) of 6 cm length were employed and the acceptor phase consisted of 1-octanol. 5% Sodium chloride was added to samples to prevent loss of the solvent during extraction. Extracts were analyzed by GC-MS and method detection limits were in the range of 1.6-5.6 ng L(-1). The method was applied for the determination of target analytes in influent samples from five Swedish wastewater treatment plants (WWTPs). All three analytes were found in very low or non-detectable concentrations. The most abundant compound was 3-acetobenzophenone found at four of the investigated WWTPs at an average concentration of 62 ng L(-1). Diclofenac amide and 4'-isobutylacetophenone were only detected above LOD at one WWTP each at a concentration of 55 and 197 ng L(-1), respectively. Samples of water entering and exiting the activated sludge treatment as well as digested sludge were also collected from one of the WWTPs. Only diclofenac amide was detected in these samples. A higher concentration was detected in the effluent from the activated sludge treatment than the influent, thus indicating the formation of this compound during treatment. In the sludge, diclofenac amide was detected at 183 ng g(-1)wet weight. Based on these results it can be concluded that the amounts of these compounds reaching WWTPs are very small, suggesting negligible risks to the aquatic environment. However, they also indicate the potential formation during the activated sludge process and accumulation into sludge for at least one of the compounds which is why further studies of these processes are needed. PMID:24840419

Manso, Jose; Larsson, Estelle; Jönsson, Jan Åke



Alternative Flotation Techniques for Wastewater Treatment: Focus on Electroflotation  

Microsoft Academic Search

During the last decades (dissolved-air) flotation has found several applications in water and wastewater treatment. Flocculation is generally required in advance for a satisfactory separation and a membrane process is often applied downstream. Examples from the literature given in the present review include heavy metals, textile dyes, food, paper industry, oily effluents, laundry wastewaters, sludge etc. and are accompanied by

K. A. Matis; E. N. Peleka



Use of Filamentous Fungi for Wastewater Treatment and Production of High Value Fungal Byproducts: A Review  

Microsoft Academic Search

Conventional biological wastewater treatment generates large amounts of low value bacterial biomass. The treatment and disposal of this excess bacterial biomass, also known as waste activated sludge, accounts for about 40–60% of the wastewater treatment plant operation cost. A different form of biomass with a higher value could significantly change the economics of wastewater treatment. Fungi could offer this benefit

Sindhuja Sankaran; Samir Kumar Khanal; Nagapadma Jasti; Bo Jin; Anthony L. Pometto III; J. Hans Van Leeuwen



Evaluation of the alternative treatment processes to upgrade an Opium alkaloid wastewater treatment plant  

Microsoft Academic Search

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant

M. F. Sevimli; A. F. Aydin; I. Öztürk; H. Z. Sarikaya



EPA Science Inventory

A critical evaluation has been made of the literature regarding the sources of heavy metals in sludges from municipal wastewater treatment plants. Residential loadings of heavy metals as a percentage of total metal loads are highly variable with respect to both the particular ele...


Heat inactivation of enteric viruses in dewatered wastewater sludge.  

PubMed Central

The effect of moisture content on the rates of heat inactivation of enteric viruses in wastewater sludge was determined. The protective effect of raw sludge on poliovirus previously observed (R. L. Ward, C. S. Ashley, and R. H. Moseley, Appl. Environ. Microbiol. 32:339--346, 1976) was found to be greatly enhanced in sludge dewatered by evaporation. Other enteroviruses responded in a similar fashion. This effect did not appear to be due merely to the state of dryness of the sludge samples because in humus-deficient soil, a relatively inert material, the rate of poliovirus inactivation by heat was not significantly altered through dewatering. Instead, this effect appeared to have been caused by protective substances in the sludge, such as detergents, which are concentrated through dewatering. As reported previously (R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol. 34:681-688, 1977; R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol 36:889--897, 1978) raw sludge is not protective of reovirus, but, instead, the ionic detergents in sludge cause the rate of heat inactivation of this virus to be accelerated. Dewatering of sludge, however, was found to partially reverse this virucidal effect. Evidence is presented indicating that this reversal is caused by an unidentified protective substance in sludge also concentrated through dewatering. Finally, it was shown that the effects of raw sludge on heat inactivation of poliovirus and reovirus are greatly reduced by composting, a result that correlated with the degradation of detergents. PMID:216309

Ward, R L; Ashley, C S



The effect of copper on the structure of the ammonia-oxidizing microbial community in an activated sludge wastewater treatment plant.  


Molecular approaches based on both whole-cell and extracted DNA were applied to assess chronic and acute effects of copper on the ammonia oxidizing bacteria (AOB) community in an activated sludge system. The ammonia monooxygenase amoA gene was chosen as the functional marker to evaluate changes in the AOB community. Using in situ polymerase chain reaction, we were able to visualize the peripheric distribution of the amoA gene-possessing bacteria in activated sludge flocs. The AOB biomass content was constant in both chronic and acute toxicity experiments, but the ammonia oxidizing activity, measured as ammonia uptake rate, was different. The AOB community structural changes due to the copper presence were evaluated by multivariate analysis of the DGGE bands profiles. The chronic contamination caused a change in the AOB community compared to the control. In contrast, acute inputs led to a temporary change in the AOB community, after which the community was similar to the control. Recovery after acute intoxication was achieved after 72 h. The present study reports on the effects of chronic and acute copper contamination on the ammonia uptake ability of the AO microorganisms and the structure of the AOB community in a wastewater system and, as a consequence, gives indications on the response of wastewater plants under similar conditions. PMID:18677527

Principi, Pamela; Villa, Federica; Giussani, Barbara; Zanardini, Elisabetta; Cappitelli, Francesca; Sorlini, Claudia



Performance evaluation and steady-state kinetics of the microbial degradation of phenolic, cyanic, ammoniacal wastewater in activated sludge systems  

Microsoft Academic Search

A laboratory investigation was performed to study the effect of cyanide, powdered activated carbon (PAC) and sludge retention time (SRT) on the operation of an activated sludge system (AS) and an anoxic\\/oxic activated sludge system (A\\/O), treating synthetic wastewater containing thiocyanate, phenols and ammonia. Four bench-scale treatment systems (two AS and two A\\/O) were studied in the absence and presence



Microalgae and wastewater treatment  

PubMed Central

Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater. PMID:24936135

Abdel-Raouf, N.; Al-Homaidan, A.A.; Ibraheem, I.B.M.



Disinfection. [Wastewater treatment  

SciTech Connect

Methods of disinfection of wastewater including chlorination, ultraviolet radiation, ozone, and quaternary compounds are reviewed. Various analytical methods to detect residues of the disinfectants are described. The production of inorganic and nonvolatile organic compounds in conventional water treatment processes is reviewed. (KRM)

Haas, C.N. (Illinois Inst. of Technology, Chicago); McCreary, J.J.



Microalgae and wastewater treatment.  


Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater. PMID:24936135

Abdel-Raouf, N; Al-Homaidan, A A; Ibraheem, I B M



Prevalence and fate of Giardia cysts in wastewater treatment plants.  


The present study was conducted to review factors affecting the prevalence and concentration of Giardia in raw wastewater. The removal and inactivation efficiency of Giardia by wastewater treatment technologies was also reviewed. Data published for the prevalence of Giardia in wastewater and the removal by wastewater treatment plants was reviewed. Giardia cysts are highly prevalent in wastewater in various parts of the world, which may reflect the infection rate in the population. In 23 of 30 (76.6%) studies, all of the tested raw wastewater samples were positive for Giardia cysts at concentrations ranging from 0.23 to 100 000 cysts l(-1). The concentration of Giardia in raw wastewater was not affected by the geographical region or the socio-economic status of the community. Discharge of raw wastewater or the application of raw wastewater for irrigation may result in Giardia transmission. Activated sludge treatment resulted in a one to two orders of magnitude reduction in Giardia, whereas a stabilization pond with a high retention time removed up to 100% of the cysts from wastewater. High-rate sand filtration, ultrafiltration and UV disinfection were reported as the most efficient wastewater treatment methods for removal and disinfection of Giardia cysts. Wastewater treatment may not totally prevent the environmental transmission of Giardia cysts. The reviewed data show that a combination of wastewater treatment methods may results in efficient removal of Giardia cysts and prevent their environmental transmission. PMID:22564037

Nasser, A M; Vaizel-Ohayon, D; Aharoni, A; Revhun, M



Effects of wastewater sludge and woodchip combinations on soil properties and growth of planted hardwood trees and willows on a restored site  

Microsoft Academic Search

Sludge from wastewater treatment plants and woodchips produced from urban tree pruning residues were used to improve soil conditions of a degraded site restored by planting trees and shrubs. The release of soil nitrogen resources was set by the proportions of sludge and woodchips applied. Combining 187 kg N\\/ha of sludge in one application with 200 m3\\/ha of woodchips instead

Alain Cogliastro; Gérald Domon; Stéphane Daigle



Persistence of pathogenic prion protein during simulated wastewater treatment processes  

USGS Publications Warehouse

Transmissible spongiform encephalopathies (TSEs, prion diseases) are a class of fatal neurodegenerative diseases affecting a variety of mammalian species including humans. A misfolded form of the prion protein (PrP TSE) is the major, if not sole, component of the infectious agent. Prions are highly resistant to degradation and to many disinfection procedures suggesting that, if prions enter wastewater treatment systems through sewers and/or septic systems (e.g., from slaughterhouses, necropsy laboratories, rural meat processors, private game dressing) or through leachate from landfills that have received TSE-contaminated material, prions could survive conventional wastewater treatment Here, we report the results of experiments examining the partitioning and persistence of PrPTSE during simulated wastewater treatment processes including activated and mesophilic anaerobic sludge digestion. Incubation with activated sludge did not result in significant PrPTSE degradation. PrPTSE and prion infectivity partitioned strongly to activated sludge solids and are expected to enter biosolids treatment processes. A large fraction of PrPTSE survived simulated mesophilic anaerobic sludge digestion. The small reduction in recoverable PrPTSE after 20-d anaerobic sludge digestion appeared attributable to a combination of declining extractability with time and microbial degradation. Our results suggest that if prions were to enter municipal wastewater treatment systems, most would partition to activated sludge solids, survive mesophilic anaerobic digestion, and be present in treated biosolids. ?? 2008 American Chemical Society.

Hinckley, G.T.; Johnson, C.J.; Jacobson, K.H.; Bartholomay, C.; Mcmahon, K.D.; McKenzie, D.; Aiken, J.M.; Pedersen, J.A.



Poly-beta-hydroxybutyrate production by fast-growing rhizobia cultivated in sludge and in industrial wastewater.  


In our study, the potential of producing polyhydroxybutyrate (PHB) by cultivating fast-growing rhizobia (Sinorhizobium meliloti, Rhizobium leguminosarum bv. viciae, R. leguminosarum bv. phaseoli and R. leguminosarum bv. trifolii) in sludge and in industrial wastewater was evaluated. Results confirmed the possibility of using sludge as media for rhizobial growth. During growth, substantial quantity of PHB was accumulated and yields varied depending on the media and rhizobial species. Growing in sludge, PHB production did not exceed 3.7% w/w for all strains at the end of experiment (after 72 h). During the growth of S. meliloti, PHB yield varied and the maximum value reached 7.27% w/w after 60 h, with 1% Total Suspend Solid (TSS) sludge. Alkaline sludge pre-treatment affects rhizobial growth but did not improve the PHB accumulation. While growing S. meliloti in industrial wastewater, the PHB yields varied and the highest value was obtained with slaughterhouse wastewater (10.7% w/w) after 35 h of growth. Therefore, this work shows the potential of exploiting PHB production by rhizobia growing in wastewater or sludge which could be applied to bioplastic industry, and confirms the potential of these recyclable wastes for high production of rhizobial cells useable for legumes inoculants production. This study provides an environmentally sound way of sludge and wastewater management and use in diverse biotechnological applications. PMID:18795238

Ben Rebah, Faouzi; Prévost, Danielle; Tyagi, Rajeshwar Dayal; Belbahri, Lassaad




EPA Science Inventory

Emissions of metals and organics from a series of four wastewater sludge incinerators were determined. hree multiple hearth units and one fluidized bed combustor were tested. missions were controlled with a combination of venturi and/or tray impingement scrubbers. ne site incorpo...


Wastewater treatment of pulp and paper industry: a review.  


Pulp and paper industries generate varieties of complex organic and inorganic pollutants depending upon the type of the pulping process. A state-of-art of treatment processes and efficiencies of various wastewater treatment is presented and critically reviewed in this paper. Process description, source of wastewater and their treatment is discussed in detail. Main emphasis is given to aerobic and anaerobic wastewater treatment. In pulp and paper mill wastewater treatment aerobic treatment includes activated sludge process, aerated lagoons and aerobic biological reactors. UASB, fluidized bed, anaerobic lagoon and anaerobic contact reactors are the main technologies for anaerobic wastewater treatment. It is found that the combination of anaerobic and aerobic treatment processes is much efficient in the removal of soluble biodegradable organic pollutants. Color can be removed effectively by fungal treatment, coagulation, chemical oxidation, and ozonation. Chlorinated phenolic compounds and adsorable organic halides (AOX) can be efficiently reduced by adsorption, ozonation and membrane filtration techniques. PMID:23033705

Kansal, Ankur; Siddiqui, Nihalanwar; Gautam, Ashutosh



Wastewater and sludge control-technology options for synfuels industries  

SciTech Connect

The options examined were those of zero discharge, partial water reuse with restricted discharge of treated effluents, and unrestricted discharge of treated effluents. Analysis of cost data and performance-analyses data for several candidate secondary-wastewater-treatment unit processes indicated that combined activated-sludge/powdered-activated-carbon (AS/PAC) treatment incorporating wet-air-oxidation carbon regeneration is the most cost-effective control technology available for the removal of organic material from slagging, fixed-bed process wastewaters. Bench-scale treatability and organic-constituent removal studies conducted on process quench waters from a pilot-scale, slagging, fixed-bed gasifer using lignite as feedstock indicated that solvent extraction followed by AS/PAC treatment reduces levels of extractable and chromatographable organics to less than 1 in the final effluent. Levels of conventional pollutants also were effectively reduced by AS/PAC to the minimum water-quality standards for most receiving waters. The most favored and most cost-effective treatment option is unrestricted discharge of treated effluents with ultimate disposal of biosludges and landfilling of gasifier ash and slag. This option requires a capital expenditure of $8,260,000 and an annual net operating cost of $2,869,000 in 1978 dollars, exclusive of slag disposal. The net energy requirement of 19.6 x 10/sup 6/ kWh/year, or 15.3 kWh/1000 gal treated, is less than 6% of the equivalent energy demand associated with the zero-discharge option.

Castaldi, F.J.; Harrison, W.; Ford, D.L.



Fenton oxidation and sequencing batch reactor (SBR) treatments of high-strength semiconductor wastewater  

Microsoft Academic Search

Treatment of a high-strength semiconductor wastewater was experimentally investigated in this study. The wastewater is characterized by a strong dark color, high chemical oxygen demand (COD) concentration, presence of refractory volatile organic compound and low biodegradability. Treatment of this wastewater by traditional activated sludge method is essentially impossible. In the present work, combined physical, chemical and biological methods were synergistically

Sheng H. Lin; Chang D. Jiang




EPA Science Inventory

The report describes results from a broadly-based effort to determine the feasibility of predicting the fates of organic chemicals in diffused air, activated sludge wastewater treatment processes. The three conversion/removal mechanisms emphasized in the work were stripping, sorp...


Fluorochemical Mass Flows in a Municipal Wastewater Treatment Facility  

PubMed Central

Fluorochemicals have widespread applications and are released into municipal wastewater treatment plants via domestic wastewater. A field study was conducted at a full-scale municipal wastewater treatment plant to determine the mass flows of selected fluorochemicals. Flow-proportional, 24-h samples of raw influent, primary effluent, trickling filter effluent, secondary effluent, and final effluent and grab samples of primary, thickened, activated, and anaerobically-digested sludge were collected over ten days and analyzed by liquid chromatography electrospray-ionization tandem mass spectrometry. Significant decreases in the mass flows of perfluorohexane sulfonate and perfluorodecanoate occurred during trickling filtration and primary clarification, while activated sludge treatment decreased the mass flow of perfluorohexanoate. Mass flows of the 6:2 fluorotelomer sulfonate and perfluorooctanoate were unchanged as a result of wastewater treatment, which indicates that conventional wastewater treatment is not effective for removal of these compounds. A net increase in the mass flows for perfluorooctane and perfluorodecane sulfonates occurred from trickling filtration and activated sludge treatment. Mass flows for perfluoroalkylsulfonamides and perfluorononanoate also increased during activated sludge treatment and are attributed to degradation of precursor molecules. PMID:17180988

Schultz, Melissa M.; Higgins, Christopher P.; Huset, Carin A.; Luthy, Richard G.; Barofsky, Douglas F.; Field, Jennifer A.



Efficiency of refinery sludge biodegradation using municipal wastewater and activated sludge and effect of hydrocarbon concentration on culturable bacteria community  

Microsoft Academic Search

The efficiency of activated sludge as inoculum and municipal wastewater as diluent for the biodegradation of refinery sludge\\u000a was investigated. At a laboratory scale, biodegradation experiments carried out in an aerobic batch reactor showed that toxic\\u000a oily sludge was biodegradable after dilution. Compared with freshwater, the use of municipal wastewater for dilution clearly\\u000a enhanced the biodegradation of this toxic pollutant.

Saïd Ben Hamed; Raja Rezgui; Ayed Halleb; Abdeljelil Ghram; Ridha Oueslati; Marc Labat; Abderrazak Maaroufi



Constructed Wetlands and Waste Stabilization Ponds for municipal wastewater treatment in France: comparison of  

E-print Network

13 Constructed Wetlands and Waste Stabilization Ponds for municipal wastewater treatment in France In France, vertical flow constructed wetlands and waste stabilisation ponds are both extensive treatment Vertical Flow Constructed Wetlands, Waste Stabilization Ponds, operation and maintenance, sludge management

Paris-Sud XI, Université de


Wastewater reclamation by advanced treatment of secondary effluents  

Microsoft Academic Search

The objectives of this study were the investigation of the performance of an advanced treatment system, for the reclamation of secondary municipal effluents, and the study of the environmental quality of treated effluents. The secondary effluents from a conventional activated sludge process were fed to an advanced wastewater treatment system, consisting of a moving-bed sand filter, a granular activated carbon

M. Petala; V. Tsiridis; P. Samaras; A. Zouboulis; G. P. Sakellaropoulos



Chemical stability of acid rock drainage treatment sludge and implications for sludge management  

SciTech Connect

To assess the chemical stability of sludges generated by neutralizing acid rock drainage (ARD) with alkaline reagents, synthetic ARD was treated with hydrated lime (batch and high-density sludge process), limestone, and two proprietary reagents (KB-1 and Bauxsol). The amorphous metal hydroxide sludge produced was leached using deionized water, U.S. EPA methods (toxicity characteristic leaching procedure, synthetic precipitation leaching procedure), and the new strong acid leach test (SALT), which leaches the sludge with a series of sulfuric acid extractant solutions; the pH decreases by {approximately} 1 pH unit with each test, until the final pH is {approximately}2. Sludges precipitated by all reagents had very similar leachabilities except for KB-1 and Bauxsol, which released more aluminum. SALT showed that lowering the pH of the leaching solution mobilized more metals from the sludges. Iron, aluminum, copper, and zinc began to leach at pH 2.5-3, {approximately}4.5, {approximately}5.5, and 6-6.5, respectively. The leachability of ARD treatment sludges is determined by the final pH of the leachate. A higher neutralization potential (e.g., a greater content of unreacted neutralizing agent) makes sludges inherently more chemically stable. Thus, when ARD or any acidic metalliferous wastewater is treated, a choice must be made between efficient reagent use and resistance to acid attack. 26 refs., 5 figs., 2 tabs.

Danny M. McDonald; John A. Webb; Jeff Taylor [La Trobe University, Vic. (Australia). Environmental Geoscience




EPA Science Inventory

This report presents a critical review of the literature from laboratory and full scale studies regarding density levels of indicator and pathogenic organisms in municipal wastewater sludges and septage. The effectiveness of conventional municipal sludge stabilization processes (...



ERIC Educational Resources Information Center

Cites a recycling success story involving sludge production from wastewater and transformation into an effective plant fertilizer. Discusses related concerns such as dealing with pollutants like heavy metals and PCBs often found in sludge. Provides an example of an application of sludge produced in Chicago to an area reclamation site. (MCO)

Tenenbaum, David



Quick Startup of EGSB Reactor Seeded with Anaerobic Digestion Sludge for the Treatment of Actual Domestic Sewage under Ambient Temperature  

Microsoft Academic Search

To obtain the rapid startup of EGSB reactor seeded with anaerobic digestion sludge for the treatment of actual domestic wastewater under ambient temperature, two startup methods i.e. A and B were tried out at 25°C. For method A, reactor A (RA) was fed with brewery wastewater to incubate granular sludge and then treated domestic sewage, for method B, reactor B

Dong Chunjuan; Li Qingwei; Geng Zhaoyu; Wang Haihui; Wang Zengzhang



Wastewater Treatment I. Instructor's Manual.  

ERIC Educational Resources Information Center

This instructor's manual provides an outline and guide for teaching Wastewater Treatment I. It consists of nine sections. An introductory note and a course outline comprise sections 1 and 2. Section 3 (the bulk of the guide) presents lesson outlines for teaching the ten chapters of the manual entitled "Operation of Wastewater Treatment Plants."…

California Water Pollution Control Association, Sacramento. Joint Education Committee.


Polyelectrolyte conditioning for iron-hydroxide-containing sludge produced from electroflocculation of fermentation wastewater.  


The purpose of this study is to investigate the application of chemical conditioning method for the post-electroflocculation wastewater sludge treatment with polyelectrolytes of varying ionic characters, namely anionic, cationic and nonionic flocculating agents. Electroflocculation, a combination of the processes of electroflotation and electroprecipitation, was found effective to remove the organic and color components in monosodium glutamate fermentation wastewater. The settleability and dewaterability of the separated sludge, containing 15-20% of iron hydroxides, increased 35% and 60% due to polymer conditioning through a jar-test apparatus. The influence of shear conditions and polymer dose on the floc size, zeta potential, filterability and dewatering performance, and shear resistance of sludges was investigated. Experimental results showed that the anionic polymer acts as a better flocculating agent than both cationic and nonionic polymers, and the optimal polymer doses fall between 4.0 and 10.0 mg/g Fe sludge under corresponding shear rates of 200 300 rpm. This study also indicated that both charge neutralization and polymer bridging mechanisms operate in the sludge conditioning process. PMID:15328692

Chen, Wen-Jang; Chen, Tson-Nan; Cheng, Yang-Chu



Characterization of drinking water treatment sludge after ultrasound treatment.  


Ultrasonic technology alone or the combination of ultrasound with alkaline or thermal hydrolysis as pretreatment for anaerobic digestion of activated sludge has been extensively documented. However, there are few reports on ultrasound as pretreatment of drinking water treatment sludge (DWTS), and thereby the characteristic variability of sonicated DWTS has not been fully examined. This research presents a lab-scale study on physical, chemical and biological characteristics of a DWTS sample collected from a water plant after ultrasonic treatment via a bath/probe sonoreactor. By doing this work, we provide implications for using ultrasound as pretreatment of enhanced coagulation of recycling sludge, and for the conditioning of water and wastewater mixed sludge by ultrasound combined with polymers. Our results indicate that the most vigorous DWTS disintegration quantified by particles' size reduction and organic solubilization is achieved with 5W/ml for 30min ultra-sonication (specific energy of 1590kWh/kgTS). The Brunauer, Emmett and Teller (BET) specific surface area of sonicated DWTS flocs increase as ultra-sonication prolongs at lower energy densities (0.03 and 1W/ml), while decrease as ultra-sonication prolongs at higher energy densities (3 and 5W/ml). Additionally, the pH and zeta potential of sonicated DWTS slightly varies under all conditions observed. A shorter sonication with higher energy density plays a more effective role in restraining microbial activity than longer sonication with lower energy density. PMID:25443278

Zhou, Zhiwei; Yang, Yanling; Li, Xing; Zhang, Yang; Guo, Xuan




EPA Science Inventory

An original treatment system was designed, constructed, and operated for removal of suspended solids, turbidity, color, and BOD from the wastewaters of two paper mills which produce technical and other fine papers. The treatment process involves coagulation and flocculation follo...


Characteristics and performance of aerobic granular sludge treating rubber wastewater at different hydraulic retention time.  


The influence of hydraulic retention time (HRT, 24, 12, and 6h) on the physical characteristics of granules and performance of a sequencing batch reactor (SBR) treating rubber wastewater was investigated. Results showed larger granular sludge formation at HRT of 6h with a mean size of 2.0±0.1mm, sludge volume index of 20.1mLg(-1), settling velocity of 61mh(-1), density of 78.2gL(-1) and integrity coefficient of 9.54. Scanning electron microscope analyses revealed different morphology of microorganisms and structural features of granules when operated at various HRT. The results also demonstrated that up to 98.4% COD reduction was achieved when the reactor was operated at low HRT (6h). Around 92.7% and 89.5% removal efficiency was noted for ammonia and total nitrogen in the granular SBR system during the treatment of rubber wastewater. PMID:24704837

Rosman, Noor Hasyimah; Nor Anuar, Aznah; Chelliapan, Shreeshivadasan; Md Din, Mohd Fadhil; Ujang, Zaini



Mangere WastewaterMangere WastewaterMangere WastewaterMangere WastewaterMangere WastewaterMangere WastewaterMangere WastewaterMangere Wastewater Treatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreat  

E-print Network

Mangere WastewaterMangere WastewaterMangere Wastewater Treatment PlantTreatment PlantTreatment PlantTreatment PlantTreatmentTechnical Issues and Innovations Transformed the old Mangere Wastewater Treatment PlantTransformed the old Mangere Wastewater Treatment Plant 5 year project, treatment processes have been replaced5 year project, treatment

Prevedouros, Panos D.


Onsite Wastewater Treatment Systems: Aerobic Treatment Unit  

E-print Network

. Onsite wastewater treatment systems Single-compartment trash tank Chlorinator Aerobic treatment unit Spray heads Pump tank Bruce Lesikar Professor and Extension Agricultural Engineer The Texas A&M System Aerobic treatment units, which are certified...

Lesikar, Bruce J.



Electrochemical technologies in wastewater treatment  

Microsoft Academic Search

This paper reviews the development, design and applications of electrochemical technologies in water and wastewater treatment. Particular focus was given to electrodeposition, electrocoagulation (EC), electroflotation (EF) and electrooxidation. Over 300 related publications were reviewed with 221 cited or analyzed. Electrodeposition is effective in recover heavy metals from wastewater streams. It is considered as an established technology with possible further development

Guohua Chen



Rate determination and distribution of anammox activity in activated sludge treating swine wastewater.  


This paper presents a quantitative investigation and analysis of anammox activity in sludge taken from biological swine wastewater treatment plants. An incubation experiment using a (15)N tracer technique showed anammox activity in sludge taken from 6 out of 13 plants with the rate ranging from 0.0036 micromol-N(2)/g-VSS/h to 3.1 micromol-N(2)/g-VSS/h, and in a biofilm with the highest activity at 25.8 micromol-N(2)/g-VSS/h. It is notable that 9 out of 11 sludges in which the pH was maintained between 6.6 and 8.1 retained anammox activity, while those with either a lower or higher pH did not. Moreover, anammox-positive sludge had a significantly higher concentration of NO(2)(-)-N plus NO(3)(-)-N than did anammox-negative sludge. A significant difference was not observed between anammox-positive and -negative sludge regarding BOD/NH(4)(+)-N in the influent, DO concentration in aeration tanks, and the concentrations of NH(4)(+)-N, free nitric acid, and free ammonia. PMID:19944599

Waki, Miyoko; Yasuda, Tomoko; Suzuki, Kazuyoshi; Sakai, Takahiro; Suzuki, Naoto; Suzuki, Ryoji; Matsuba, Kenji; Yokoyama, Hiroshi; Ogino, Akifumi; Tanaka, Yasuo; Ueda, Shingo; Takeuchi, Mio; Yamagishi, Takao; Suwa, Yuichi



Impact of separate urine collection on wastewater treatment systems.  


Wastewater treatment should not only be concerned with urban hygiene and environmental protection, but development of a sustainable society must also be considered. This implies a minimisation of the energy demand and potential recovery of finite minerals. Urine contains 80% of the nitrogen (N) and 45% of the phosphorus (P) in wastewater. Separate collection and treatment would improve effluent quality and save energy in centralised biological nutrient removal (BNR). BNR processes are not optimal to treat water with very low N concentration resulting from separate urine collection. Relying on nutrient removal through sludge production, methanation of the sludge, subsequent nutrient removal from the digestion effluent results in optimised and more sustainable wastewater treatment. This paper quantitatively evaluates this option and discusses the potential. PMID:12926626

Wilsenach, J; van Loosdrecht, M



Utilizing acid mine drainage sludge and coal fly ash for phosphate removal from dairy wastewater.  


This study aims to investigate a new and sustainable approach for the reuse of industrial by-products from wastewater treatment. The dairy industry produces huge volumes of wastewater, characterized by high levels of phosphate that can result in eutrophication and degradation of aquatic ecosystems. This study evaluated the application of acid mine drainage (AMD) sludge, coal fly ash, and lignite as low-cost adsorbents for the removal of phosphate from dairy wastewater. Material characterization using X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis revealed significant amounts of crystalline/amorphous Fe/Al/Si/Ca-based minerals and large surface areas of AMD sludge and fly ash. Batch adsorption isotherms were best described using the Freundlich model. The Freundlich distribution coefficients were 13.7 mg(0.577) L(0.423) g(-1) and 16.9 mg(0.478) L(0.522) g(-1) for AMD sludge and fly ash, respectively, and the nonlinearity constants suggested favourable adsorption for column applications. The breakthrough curves of fixed-bed columns, containing greater than 10 wt% of the waste materials (individual or composite blends) mixed with sand, indicated that phosphate breakthrough did not occur within 100 pore volumes while the cumulative removal was 522 and 490 mg kg(-1) at 10 wt% AMD sludge and 10 wt% fly ash, respectively. By contrast, lignite exhibited negligible phosphate adsorption, possibly due to small amounts of inorganic minerals suitable for phosphate complexation and limited surface area. The results suggest that both AMD sludge and fly ash were potentially effective adsorbents if employed individually at a ratio of 10 wt% or above for column application. PMID:24617077

Wang, Y R; Tsang, Daniel C W; Olds, William E; Weber, Paul A



Application of Sludges and Wastewaters on Agricultural Land: A Planning and Educational Guide, MCD-35. Research Bulletin 1090.  

ERIC Educational Resources Information Center

This report addresses the application of agricultural processing wastes, industrial and municipal wastes on agricultural land as both a waste management and resource recovery and reuse practice. The document emphasizes the treatment and beneficial utilization of sludge and wastewater as opposed to waste disposal. These objectives are achieved…

Knezek, Bernard D., Ed.; Miller, Robert H., Ed.


Techno-economic analysis of wastewater sludge gasification: a decentralized urban perspective.  


The successful management of wastewater sludge for small-scale, urban wastewater treatment plants, (WWTPs), faces several financial and environmental challenges. Common management strategies stabilize sludge for land disposal by microbial processes or heat. Such approaches require large footprint processing facilities or high energy costs. A new approach considers converting sludge to fuel which can be used to produce electricity on-site. This work evaluated several thermochemical conversion (TCC) technologies from the perspective of small urban WWTPs. Among TCC technologies, air-blown gasification was found to be the most suitable approach. A gasification-based generating system was designed and simulated in ASPEN Plus® to determine net electrical and thermal outputs. A technical analysis determined that such a system can be built using currently available technologies. Air-blown gasification was found to convert sludge to electricity with an efficiency greater than 17%, about triple the efficiency of electricity generation using anaerobic digester gas. This level of electricity production can offset up to 1/3 of the electrical demands of a typical WWTP. Finally, an economic analysis concluded that a gasification-based power system can be economically feasible for WWTPs with raw sewage flows above 0.093m(3)/s (2.1 million gallons per day), providing a profit of up to $3.5 million over an alternative, thermal drying and landfill disposal. PMID:24727699

Lumley, Nicholas P G; Ramey, Dotti F; Prieto, Ana L; Braun, Robert J; Cath, Tzahi Y; Porter, Jason M



Biological treatment of a seafood processing wastewater  

SciTech Connect

The seafood industry in Tampa is a multi-million dollar-per-year industry which heavily impacts the environment with large volumes of wastewater containing high concentrations of suspended solids and nitrogen. A 10 liter per day, bench-scale, wastewater treatment facility was designed, constructed, and operated for approximately eight (8) months to collect treat ability data on a seafood-processing wastewater. The bench-scale reactor consisted of a single-sludge, extended aeration, modified Ludzack-Ettinger (MLE) process for biologically removing carbon, nitrogen, and phosphorus from the wastewater. Influent and effluent data collected on the system included: chemical oxygen demand (COD), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, total nitrogen (TN), pH, total phosphorus (TP), dissolved oxygen (DO), alkalinity, and temperature. All analyses were performed in accordance with Standard Methods (1992). Typical influent characteristics were: 900--4,000 mg/L COD, 45--110 mg/L TKN, 150--2,000 mg/L TSS, and 40--80 mg/L TP. Solids residence time (SRT) served as the primary control parameter with average STR's of 4.5, 6.4, 8.5, and 30.9 days observed during the study. The following biokinetic constants were determined from the data: a yield coefficient (Y) of 0.49 mg TSS/mg COD and an endogenous decay coefficient (k{sub e}) of 0.11 days{sup {minus}1}.

Mines, R.O. Jr.; Robertson, R.R. II



Partitioning of nutrients and micropollutants along the sludge treatment line: a case study.  


A 2-year sampling campaign was conducted in three wastewater treatment plants of various sizes in the Rome area to assess the occurrence of nutrients and micropollutants among primary, secondary and digested sludge. The primary purpose was to evaluate the quality of different sludge types and their suitability for agricultural use. Primary sludge was consistently more polluted than secondary in terms of organic micropollutants, whereas heavy metals partitioned equally among the sludge types. In digested sludge, the heavy metal concentrations were always below limit values proposed for agricultural utilisation. In contrast, organic micropollutants concentrated during anaerobic digestion and affected the quality of the digested sludge. Secondary sludge resulted less polluted and richer in nitrogen and phosphorus (up to three times) than primary sludge and is hence more suitable for agricultural use. Separate processing of primary and secondary sludge might therefore be an innovative option for sludge management that could maximise the possibilities of agricultural use of secondary sludge and limit disposal problems only to primary sludge. In fact, primary sludge could be easily treated and disposed of by conventional processes including thickening, anaerobic digestion, centrifugation and incineration, whereas the difficult digestibility of secondary sludge could be improved by disintegration pre-treatment before stabilisation. PMID:23589264

Gianico, A; Braguglia, C M; Mascolo, G; Mininni, G



Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogenproduction.  


The increasing sludge generated in wastewater treatment plants poses a threat to the environment. Based on the traditional processes, sludge dewatered by usual methods was further dewatered by hydraulic compression and the filtrate released was treated by anaerobic fermentation. The difficulties in sludge dewatering were associated with the existence of sludge flocs or colloidal materials. A suitable CaO dosage of 125 mg/g dry sludge (DS) could further decrease the moisture content of sludge from 82.4 to 50.9 %. The filtrate from the dewatering procedure was a potential substrate for biohydrogen production. Adding zero-valent iron (ZVI) into the anaerobic system improved the biohydrogen yield by 20 %, and the COD removal rate was lifted by 10 % as well. Meanwhile, the sludge morphology and microbial community were altered. The novel method could greatly reduce the sludge volume and successfully treated filtrate along with the conversion of organics into biohydrogen. PMID:25192669

Yu, Li; Yu, Yang; Jiang, Wentian; Wei, Huangzhao; Sun, Chenglin



Simultaneous wastewater treatment and biological electricity generation  

E-print Network

Simultaneous wastewater treatment and biological electricity generation B.E. Logan Department accomplishing wastewater treatment in processes based on microbial fuel cell technologies. When bacteria oxidize.4 £ 106 L of wastewater, a wastewater treatment plant has the potential to become a 2.3 MW power plant


Residential Wastewater Treatment Systems  


... Safety and Quality Medical Devices Pharma / Biotech Plastics Sustainability and Environment Water and Wastewater Services By Type ... NSF Mark Jobs and Careers Awards Commitment to Sustainability NSF in the Community NSF Online Locations Related ...


ENVIRONMENTAL BIOTECHNOLOGY Brewery wastewater treatment using air-cathode  

E-print Network

ENVIRONMENTAL BIOTECHNOLOGY Brewery wastewater treatment using air-cathode microbial fuel cells wastewater treatment using microbial fuel cells (MFCs) will require a better understanding of how operational using actual wastewaters. The efficiency of wastewater treatment of a beer brewery wastewater


Water treatment plant sludge disposal into stabilization ponds.  


Researchers have paid particular attention to the disposal of sludge produced in water treatment plants (WTPs) into wastewater treatment plants (WWTPs) for further processing, mainly because it is considered an attractive alternative for the treatment of waste generated in water production processes. This study evaluated the effects of flow equalization and disposal of sludge, from a conventional WTP, into a WWTP system that includes an anaerobic stabilization pond followed by a facultative pond. During the period of sludge discharge from the WTP into the wastewater system, the influent to the WWTP presented an increase of 17% (from 171 to 200 mg L(-1)) of total suspended solids (TSS) and a 7.0% flow rate increase, without showing adverse effects on the organic load, TSS and nutrients removal. The most significant impact observed in the WWTP was the increase of solids accumulation rate in the anaerobic pond, with a value of 141 mm/year during the sludge discharge period. The operating time, before the dredging and desludging cycles required for this specific anaerobic pond, decreased from 12.7 to 10.4 years, which is consistent with previous studies in literature. Thus, based on the observed parameters of this study, it is viable to release solids from a WTP effluent into a WWTP that includes anaerobic stabilization ponds followed by a facultative pond. Indeed, this process scheme becomes a viable technical, environmental, and economical alternative for small to medium WWTPs. PMID:23416593

Filho, Sidney Seckler Ferreira; Piveli, Roque Passos; Cutolo, Silvana Audrá; de Oliveira, Alexandre Alves



Water footprint assessment for wastewater treatment: method, indicator, and application.  


The water footprint in terms of the sum of both direct and indirect water cost of wastewater treatment is for the first time accounted in this work. On the basis of the hybrid method as a combination of process analysis and input-output analysis, a detailed water footprint accounting procedure is provided to cover the supply chain of a wastewater treatment plant. A set of indices intending to reveal the efficiency as well as renewability of wastewater treatment systems are devised as parallels of corresponding indicators in net energy analysis for energy supply systems. A case study is carried out for the Beijing Space City wastewater treatment plant as a landmark project. The high WROI (water return on investment) and low WIWP (water investment in water purified) indicate a high efficiency and renewability of the case system, illustrating the fundamental function of wastewater treatment for water reuse. The increasing of the wastewater and sludge treatment rates are revealed in an urgent need to reduce the water footprint of China and to improve the performance of wastewater treatment. PMID:23777208

Shao, Ling; Chen, G Q



Thermophilic biological nitrogen removal in industrial wastewater treatment.  


Nitrification is an integral part of biological nitrogen removal processes and usually the limiting step in wastewater treatment systems. Since nitrification is often considered not feasible at temperatures higher than 40 °C, warm industrial effluents (with operating temperatures higher than 40 °C) need to be cooled down prior to biological treatment, which increases the energy and operating costs of the plants for cooling purposes. This study describes the occurrence of thermophilic biological nitrogen removal activity (nitritation, nitratation, and denitrification) at a temperature as high as 50 °C in an activated sludge wastewater treatment plant treating wastewater from an oil refinery. Using a modified two-step nitrification-two-step denitrification mathematical model extended with the incorporation of double Arrhenius equations, the nitrification (nitrititation and nitratation) and denitrification activities were described including the cease in biomass activity at 55 °C. Fluorescence in situ hybridization (FISH) analyses revealed that Nitrosomonas halotolerant and obligatehalophilic and Nitrosomonas oligotropha (known ammonia-oxidizing organisms) and Nitrospira sublineage II (nitrite-oxidizing organism (NOB)) were observed using the FISH probes applied in this study. In particular, this is the first time that Nitrospira sublineage II, a moderatedly thermophilic NOB, is observed in an engineered full-scale (industrial) wastewater treatment system at temperatures as high as 50 °C. These observations suggest that thermophilic biological nitrogen removal can be attained in wastewater treatment systems, which may further contribute to the optimization of the biological nitrogen removal processes in wastewater treatment systems that treat warm wastewater streams. PMID:23657583

Lopez-Vazquez, C M; Kubare, M; Saroj, D P; Chikamba, C; Schwarz, J; Daims, H; Brdjanovic, D



Comparative effectiveness of membrane bioreactors, conventional secondary treatment, and disinfection to remove microorganisms from municipal wastewaters  

Technology Transfer Automated Retrieval System (TEKTRAN)

Log removals of bacterial indicators, coliphage, and enteric viruses were studied in three membrane bioreactor activated-sludge (MBR) and two conventional secondary activated-sludge municipal wastewater treatment plants during three disinfection seasons (May–Oct.). In total, 73 regular samples were ...


Effect of Organic Loading on Membrane Fouling in Membrane Bioreactor for Berberine Pharmaceutical Wastewater Treatment  

Microsoft Academic Search

In order to specify the effects of organic loading on membrane fouling, the relationships of organic loadings, activated sludge properties and membrane fouling rates were studied based on statistical analysis of the long-term operation data of a lab-scale MBR for berberine pharmaceutical wastewater treatment. Results showed that, the activated sludge properties were directly determined by organic loading rate (OLR) and

Guanglei Qiu; Yonghui Song; Peng Yuan; Ping Zeng; Liang Duan; Xiaoyou Feng



Mathematical modeling of upflow anaerobic sludge blanket (UASB) reactor treating domestic wastewater.  


Although the upflow anaerobic sludge blanket (UASB) reactor has been widely applied for domestic wastewater treatment in many developing countries, there is no sufficient mathematical model for proper design and operation of the reactor. An empirical model based on non-linear regression was developed to represent the physical and chemical removal of suspended solids (SS) in the reactor. Moreover, a simplified dynamic model based on ADM1 and the empirical model for SS removal was developed for anaerobic digestion of the entrapped SS and dissolved matter in the wastewater. The empirical model showed that effluent suspended chemical oxygen demand (COD(ss)) concentration is directly proportional to the influent COD(ss) concentration and inversely proportional to both the hydraulic retention time (HRT) of the reactor and wastewater temperature. For obtaining sufficient COD(ss) removal, the HRT of the UASB reactor must be higher than 4 h, and higher HRT than 12 h slightly improved COD(ss) removal. The dynamic model results showed that the required time for filling the reactor with sludge mainly depends on influent total chemical oxygen demand (COD(t)) concentration and HRT. The influent COD(t) concentration, HRT and temperature play a crucial role on the performance of the reactor. The results indicated that shorter HRT is needed for optimization of COD(t) removal, as compared with optimization of COD(t) conversion to methane. Based on the model results, the design HRT of the UASB reactor should be selected based on the optimization of wastewater conversion and minimization of biodegradable SS accumulation in the sludge bed, not only based on COD removal, to guarantee a stable reactor performance. PMID:23128617

Elmitwalli, Tarek




Microsoft Academic Search

The production of wastewater treatment sludge, the basic characteristics of the sludge and the state of the water in the sludge are described in this paper. The methods for the determination of bound water content are discussed. The literature (including patents) on sludge dewatering and drying is reviewed, including vacuum filters, belt presses, centrifuges, direct dryers, indirect dryers and combined

Guohua Chen; Po Lock Yue; Arun S. Mujumdar



Biological treatment and nanofiltration of denim textile wastewater for reuse.  


This study aims at coupling of activated sludge treatment with nanofiltration to improve denim textile wastewater quality to reuse criteria. In the activated sludge reactor, the COD removal efficiency was quite high as it was 91+/-2% and 84+/-4% on the basis of total and soluble feed COD, respectively. The color removal efficiency was 75+/-10%, and around 50-70% of removed color was adsorbed on biomass or precipitated within the reactor. The high conductivity of the wastewater, as high as 8 mS/cm, did not adversely affect system performance. Although biological treatment is quite efficient, the wastewater does not meet the reuse criteria. Hence, further treatment to improve treated water quality was investigated using nanofiltration. Dead-end microfiltration (MF) with 5 microm pore size was applied to remove coarse particles before nanofiltration. The color rejection of nanofiltration was almost complete and permeate color was always lower than 10 Pt-Co. Similarly, quite high rejections were observed for COD (80-100%). Permeate conductivity was between 1.98 and 2.67 mS/cm (65% conductivity rejection). Wastewater fluxes were between 31 and 37 L/m2/h at 5.07 bars corresponding to around 45% flux declines compared to clean water fluxes. In conclusion, for denim textile wastewaters nanofiltration after biological treatment can be applied to meet reuse criteria. PMID:17976906

Sahinkaya, Erkan; Uzal, Nigmet; Yetis, Ulku; Dilek, Filiz B



Polyelectrolytes: Wastewater and sewage treatment. (Latest citations from the Selected Water Resources Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning polyelectrolytes in wastewater and water treatment. Topics include flocculation, coagulation, separation techniques, pollutant identification, water pollution sources, and sludge dehydration. Hospital wastewater processing, methods of synthesizing polyelectrolyte complexes, and performance evaluations of polyelectrolytes are also discussed. (Contains 250 citations and includes a subject term index and title list.)

Not Available



Effect of ambient temperatures on disinfection efficiency of various sludge treatment technologies.  


Sewage sludge produced during municipal wastewater treatment has to be treated efficiently in order to reduce impacts on the environment and on public health. In Germany and many countries, large quantities of sludge are reused in agriculture in order to recycle nutrients and organic material. In order to quantify the effect of different ambient temperatures on conventional and advanced sludge treatment technologies as well as on disinfection efficiency, a comprehensive research study was performed at Braunschweig Institute of Technology. The detailed results show that ambient temperature has a strong effect on biological liquid sludge stabilization and on natural dewatering and drying technologies, although microbiological quality of treated sludge, indicated by Escherichia coli concentration, does not meet the requirements for unrestricted reuse in agriculture. Composting and lime treatment of sludge are most efficient on reducing E. coli, as high temperatures and high pH values arise in the material respectively. PMID:24434963

Bauerfeld, Katrin



Optimized Control Structure for a Wastewater Treatment Benchmark  

E-print Network

Optimized Control Structure for a Wastewater Treatment Benchmark Michela Mulas , Antonio Carlos structure design the efficiency of a wastewater treatment plant can be improved, minimizing operational WASTEWATER TREATMENT PLANT Wastewater treatment plant pro

Skogestad, Sigurd


Removal of carbon and nutrients from domestic wastewater using a low investment, integrated treatment concept  

Microsoft Academic Search

An integrated chemical–physical–biological treatment concept for the low-cost treatment of domestic wastewater is proposed. Domestic wastewater was subjected to a chemically enhanced primary treatment (CEPT), followed by treatment in an upflow anaerobic sludge blanket (UASB) reactor. In addition, a regenerable zeolite was used to remove NH4+, either after CEPT pretreatment or after biological treatment in the UASB reactor. The CEPT

Sunny Aiyuk; Joyce Amoako; Lutgarde Raskin; Adrianus van Haandel; Willy Verstraete



Wastewater Treatment: The Natural Way  

NASA Technical Reports Server (NTRS)

Wolverton Environmental Services, Inc. is widely acclaimed for innovative work in natural water purification which involves use of aquatic plants to remove pollutants from wastewater at a relatively low-cost. Haughton, Louisiana, visited Wolverton's artificial marsh test site and decided to use this method of wastewater treatment. They built an 11 acre sewage lagoon with a 70 by 900 foot artificial marsh called a vascular aquatic plant microbial filter cell. In the cell, microorganisms and rooted aquatic plants combine to absorb and digest wastewater pollutants, thereby converting sewage to relatively clean water. Raw waste water, after a period in the sewage lagoon, flows over a rock bed populated by microbes that digest nutrients and minerals from the sewage thus partially cleaning it. Additional treatment is provided by the aquatic plants growing in the rock bed, which absorb more of the pollutants and help deodorize the sewage.



Environmental biodegradability of [(14) C] single-walled carbon nanotubes by Trametes versicolor and natural microbial cultures found in new bedford harbor sediment and aerated wastewater treatment plant sludge.  


Little is known about environmental biodegradability or biotransformations of single-walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible biotransformations (i.e., biodegradation) in environmental media. In the present study, [(14) C]SWNT were utilized to track biodegradation over 6 mo by pure liquid culture of the fungus Trametes versicolor and mixed bacterial isolates from field-collected sediment or aerated wastewater treatment plant sludge. The mixed cultures were chosen as more environmentally relevant media where SWNT will likely be deposited under both aerobic and anaerobic conditions. Activity of [(14) C] was assessed in solid, aqueous, and (14) CO2 gaseous phases to determine amounts of intact SWNT, partially soluble SWNT degradation products, and mineralized SWNT, respectively, during the 6 mo of the experiment. Mass balances based on radiocarbon activity were approximately 100% over 6 mo, and no significant degradation of SWNT was observed. Approximately 99% of the [(14) C] activity remained in the solid phase, 0.8% in the aqueous phase, and less than 0.1% was mineralized to (14) CO2 , regardless of culture type. These results suggest that SWNT are not readily biodegraded by pure fungal cultures or environmental microbial communities, and are likely persistent in environmental media. Environ Toxicol Chem 2014;9999:1-5. © 2014 SETAC. PMID:25352477

Parks, Ashley N; Chandler, G Thomas; Ho, Kay T; Burgess, Robert M; Ferguson, P Lee




EPA Science Inventory

This document describes a promising technology ? autothermal thermophilic aerobic digestion ? for meeting the current and proposed U.S. federal requirements for pathogen controJ and land application of municipal wastewater sludge. Autothermal thermophilic aerobic digestion, or AT...



EPA Science Inventory

In order to provide data to support regulations on municipal wastewater sludge incineration, emissions of metals, hexavalent chromium, nickel subsulfide, polychlorinated dibenzo-dioxins and furans (PCDD/PCDFs), semivolatile and volatile organic compounds, carbon monoxide (CO)...


Composting and Phytoremediation Treatment of Petroleum Sludge  

Microsoft Academic Search

Composting and phytoremediation using elephant grass (Penninsetum purpureum) were compared in experiments aimed at investigating the potential of both techniques in the treatment of petroleum sludge. The compost consisted of poultry manure and sawdust. N-P-K fertilizer was used for biostimulation of indigenous microbes. It also served to enhance the growth of the elephant grass. The sludge was mixed with agricultural

Josiah M. Ayotamuno; Reginald B. Kogbara; Eriye A. Agele; Onozemini S. Agoro



Aerobic domestic waste water treatment in a pilot plant with complete sludge retention by cross-flow filtration  

Microsoft Academic Search

An aerobic wastewater treatment pilot plant with cross-flow filtration was operated for more than 300 days to examine whether reduced sludge production and stable treatment performance can be achieved when sludge is completely retained. The volumetric loads ranged between 0.9 and 2.0 g COD·1?1·day?1. Technical observations were: the oxygen transfer rate became poor at high sludge concentrations; membrane capacities declined

E. B. Muller; A. H. Stouthamer; H. W. van Verseveld; D. H. Eikelboom



Wastewater Treatment I. Student's Guide.  

ERIC Educational Resources Information Center

This student's guide is designed to provide students with the job skills necessary for the safe and effective operation and maintenance of wastewater treatment plants. It consists of three sections. Section 1 consists of an introductory note outlining course objectives and the format of the guide. A course outline constitutes the second section.…

California Water Pollution Control Association, Sacramento. Joint Education Committee.


Imprinted Polymers in Wastewater Treatment  

SciTech Connect

In wastewater treatment, a method that specifically recognizes a variety of impurities in a flexible manner would be useful for treatment facilities with varying needs. Current purification techniques (i.e. bacteria, oxidation, reduction, precipitation and filtration) are nonspecific and difficult to control in complex mixtures. Heavy metal removal is particularly important in improving the efficiency of wastewater treatment, as they inhibit or even destroy the bacteria used for filtration. Imprinting polymerization is a technique that allows for the efficient removal of specific compounds and has been used in purification of enantiomers. It has potential to be applied in wastewater systems with the impurities acting as the template for the imprinting polymerization. The polymer with the bound impurities intact can then be removed via precipitation. After removal of the impurity the polymer can be reused. Data for the imprinting polymerization of polyacrylates and polyacrylamides for several metal complexes will be presented. Imprinting polymerization in combination with emulsion polymerization to improve the removal of hydrophobic contaminants will be described. Removal efficiencies will be presented and compared with conventional wastewater treatment methods.

Eastman, Christopher; Goodrich, Scott; Gartner, Isabelle; Mueller, Anja



Green Systems for Wastewater Treatment  

ERIC Educational Resources Information Center

Plants found in marshlands and wetlands in many parts of the world may play an increasing part in a very new, yet very old approach to treatment of water and wastewater--the application of biological methods. Biological water pollution control methods being utilized around the world are examined. (BT)

Environmental Science and Technology, 1975



The survival of pathogens in soil treated with wastewater sludge and in potatoes grown in such soil.  


The prevalence of pathogens on potatoes (Solanum tuberosum) grown in soil amended with a pathogen rich wastewater sludge was investigated. Bacteria of the family Enterobacteriaceae are important pathogens causing intestinal and systemic illness of humans and other animals. Type B sludge was used. Sludges investigated are the high metal and the low metal sludges. Microorganisms in the sludge-amended soil were using culture-based technique. Salmonella and E. coli were observed in tested soil samples. No microorganisms were isolated from control samples taken throughout the process of the experiment. At harvest time, some of the potato samples from LMS soil were contaminated. These potatoes were subjected to further investigation using molecular techniques (polymerase chain reaction) with fD1 and rP2 as primers. Organisms identified from the sequenced potato peel samples with the BLAST search tool included Enterobacter agglomerans (Pantoea agglomerans), several Buttiauxella spp., Pectobacterium spp., Erwinia spp. and a few Pantoea spp. Other than the E. agglomerans, which is commonly found in the gut and upper respiratory tract of humans and in the environment, all the other species identified were found to be mainly either plant or soil pathogens. The E. agglomerans are not primary pathogens but secondary opportunistic pathogens particularly in immunocompromised individuals. These results suggest that growing high risk crops using wastewater sludge contaminated soil may lead to limited infestation of produce with primary pathogens. It appears that the use of HMS due to early pathogen die-off provides less risk of infection than the LMS. However, proper treatment of wastewater sludge to reduce pathogen load is essential prior to its use as soil conditioner. PMID:17087382

Chale-Matsau, J R B; Snyman, H G



Application of the SCADA system in wastewater treatment plants.  


The implementation of the SCADA system has a positive impact on the operations, maintenance, process improvement and savings for the City of Houston's Wastewater Operations branch. This paper will discuss the system's evolvement, the external/internal architecture, and the human-machine-interface graphical design. Finally, it will demonstrate the system's successes in monitoring the City's sewage and sludge collection/distribution systems, wet-weather facilities and wastewater treatment plants, complying with the USEPA requirements on the discharge, and effectively reducing the operations and maintenance costs. PMID:11515944

Dieu, B




EPA Science Inventory

The study evaluates the effects of enzyme augmentation on municipal wastewater (MWW) sludge anaerobic digestion. The primary objective was to examine the impact of using enzymes to enhance the degradation of the cellulosic and the oil- and grease-rich sludge fractions. The additi...


Reuse of acid coagulant-recovered drinking waterworks sludge residual to remove phosphorus from wastewater  

NASA Astrophysics Data System (ADS)

Acid coagulant-recovered drinking waterworks sludge residual (DWSR) is a waste product from drinking waterworks sludge (DWS) treatment with acid for coagulant recovery. In this study, we evaluated DWSR as a potential phosphorus (P) removing material in wastewater treatment by conducting a series of batch and semi-continuous tests. Batch tests were carried out to study the effects of pH, initial concentration, and sludge dose on P removal. Batch test results showed that the P removal efficiency of DWSR was highly dependent on pH. Calcinated DWSR (C-DWSR) performed better in P removal than DWSR due to its higher pH. At an optimum initial pH value of 5-6 and a sludge dose of 10 g/L, the P removal rates of DWSR and DWS decreased from 99% and 93% to 84% and 14%, respectively, and the specific P uptake of DWSR and DWS increased from 0.19 and 0.19 mg P/g to 33.60 and 5.72 mg P/g, respectively, when the initial concentration was increased from 2 to 400 mg/L. The effective minimum sludge doses of DWSR and DWS were 0.5 g/L and 10 g/L, respectively, when the P removal rates of 90% were obtained at an initial concentration of 10 mg/L. Results from semi-continuous test indicated that P removal rates over 99% were quickly achieved for both synthetic and actual wastewater (lake water and domestic sewage). These rates could be maintained over a certain time under a certain operational conditions including sludge dose, feed flow, and initial concentration. The physicochemical properties analysis results showed that the contents of aluminum (Al) and iron (Fe) in DWSR were reduced by 50% and 70%, respectively, compared with DWS. The insoluble Al and Fe hydroxide in DWS converted into soluble Al and Fe in DWSR. Metal leaching test results revealed that little soluble Al and Fe remained in effluent when DWSR was used for P removal. We deduced that chemical precipitation might be the major action for P removal by DWSR and that adsorption played only a marginal role.

Yang, Lan; Wei, Jie; Zhang, Yumei; Wang, Jianli; Wang, Dongtian



Sludge quality after 10-20 years of treatment in reed bed systems.  


The effect on the environment of the operation of sludge treatment in reed beds (STRB) system is seen as quite limited compared to traditional sludge treatment systems such as mechanical dewatering, drying and incineration with their accompanying use of chemicals and energy consumption. There are several STRB systems in Denmark receiving sludge from urban wastewater treatment plants. Stabilization and mineralization of the sludge in the STRB systems occur during a period between 10 and 20 years, where after the basins are emptied and the sludge residue typically is spread on agricultural land. In the present study, the sludge residue quality after treatment periods of 10-20 years from four Danish STRBs is presented. After reduction, dewatering and mineralization of the feed sludge (dry solid content of 0.5-3 %) in the STRB systems, the sludge residue achieved up to 26 % dry solid, depending on the sludge quality and dimensioning of the STRB system. The concentration of heavy metals and hazardous organic compounds in the sludge residue that are listed in the Danish and EU legislation for farmland application of sludge was below the limit values. The nitrogen and phosphorus concentrations as an average in the sludge residue were 28 and 36 g/kg dry solid (DS), respectively. In addition, mineralization on average across the four STRB systems removed up to 27 % of the organic solids in the sludge. The investigation showed that the sludge residue qualities of the four STRBs after a full treatment period all complied with the Danish and European Union legal limits for agricultural land disposal. PMID:25422113

Nielsen, Steen; Bruun, Esben Wilson



Orientation to Municipal Wastewater Treatment. Training Manual.  

ERIC Educational Resources Information Center

Introductory-level material on municipal wastewater treatment facilities and processes is presented. Course topics include sources and characteristics of municipal wastewaters; objectives of wastewater treatment; design, operation, and maintenance factors; performance testing; plant staffing; and laboratory considerations. Chapter topics include…

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.



EPA Science Inventory

Treatment plants receiving wastewaters from domestic/commercial sources and receiving wastewater from domestic/commercial plus industrial sources were evaluated to assess toxicity reduction and determine the importance of source. Seven-day renewal fathead minnow survival and grow...


Methanogenic population dynamics assessed by real-time quantitative PCR in sludge granule in upflow anaerobic sludge blanket treating swine wastewater.  


A pilot-scale upflow anaerobic sludge blanket (UASB) treating swine wastewater was operated for 382 days to evaluate the process performance and methanogenic population dynamics. A real-time quantitative PCR (QPCR) was used to detect and quantify the 16S rRNA gene concentrations of the domain Archaea, the four methanogenic orders, and the two aceticlastic families. Extended intervals of consistently stable and efficient wastewater treatment with a final hydraulic retention time (HRT) of 3.5 days were sustained. A high abundance of hydrogenotrophic methanogens was observed, with Methanobacteriales as the major group, suggesting that hydrogenotrophic methanogenesis, with the syntrophic oxidation of volatile fatty acids (VFAs), was a major route of methane formation. This phenomenon was mainly attributed to the high ammonium concentration in swine wastewater, which has a severe inhibitory effect mainly on aceticlastic methanogens. Although there was no significant growth of Methanosaetaceae, its abundance contributed to the formation and maintenance of granule. PMID:19369072

Song, Minkyung; Shin, Seung Gu; Hwang, Seokhwan



Ozone treatment of textile wastewaters for reuse.  


Treatment of textile wastewaters by means of an ozonation pilot plant are described. Wastewaters used were produced by a dyeing and finishing factory and were first treated in an active sludge plant and filtrated through sand. In the appropriate conditions very high colour removal (95-99%) was achieved and the effluent could be reused in production processes requiring water of high quality as dyeing yarns or light colorations. Even if the chemical oxygen demand of treated waters was still in a range (75-120 mg/l, a decrease of up to 60%) that was usually considered to be too high for recycling purposes, recycling experiments were successful. The economical viability of the techniques implementation was also demonstrated and the industrial plant is currently under realisation under an EU financed project. The paper considers also the possible improvement of ozone diffusion by means of membrane contactors realised in a second pilot plant, in order to further reduce operating costs of the technique. With respect to traditional systems, the gas/liquid contact surface is much higher being that of the membrane. Ozone at the interface is therefore immediately solubilized and potentially consumed with no additional resistance to the mass transfer. PMID:11695484

Ciardelli, G; Capannelli, G; Bottino, A



Treating Sludges  

ERIC Educational Resources Information Center

Discussed are some of the ways to handle municipal and industrial wastewater treatment sludge presented at the 1978 American Chemical Society meeting. Suggestions include removing toxic materials, recovering metals, and disposing treated sewage sludge onto farm land. Arguments for and against land use are also given. (MA)

Josephson, Julian



Wet oxidation of phenol and naphthalene (as a surrogate PAH) in aqueous and sludge solution: application to coal-conversion wastewater and sludge treatment. [In autoclaves: 130 to 250/sup 0/C; 6 to 11 MPa oxygen; in water solution  

SciTech Connect

The wet oxidation of phenol and naphthalene in distilled water and municipal sludge has been investigated in a 1-L autoclave at temperatures from 130 to 250/sup 0/C, oxygen presures of 6 to 11.2 MPa, and initial phenol and naphthalene concentrations of 10 mg/L to 16 g/L and 10 mg/L to 420 mg/L, respectively. The reaction of phenol in water is rapid; 95% of the phenol degrades in less than 15 min at operating temperatures above 175/sup 0/C. The oxidation of phenol in sludge is mass-transfer limited and therefore yields lower rate-constant values. The reaction of phenol in water or sludge is postulated to involve a free-radical mechanism and proceeds in three steps: an induction step, a rapid first-order step, and a slower first-order step. The rapid first-order step for the phenol-water study is temperature dependent and follows the Arrhenius expression given. The slower first-order step is due to an inhibition of the rate of phenol oxidation by organic intermediates. The major organic intermediates formed during the wet oxidation of phenol are hydroquinone, catechol, succinic acid, and glycolic acid. Greater than 98% oxidation of naphthalene at milligram-per-liter concentrations in water was observed in less than 10 min. The rate of oxidation of naphthalene in sludge is inhibited by either mass transfer and/or oxidizable organics. A pseudo-first-order reaction was observed for the oxidation of naphthalene in water and sludge. The first-order rate constants are given. Essentially none of the naphthalene is completely oxidized to carbon dioxide and phthalic anhydride is the principal product for the wet oxidation of naphthalene.

Harris, M.T.; Jolley, R.L.; Oswald, G.E.; Rose, J.C.



Optimization of Ozonation Process for the Reduction of Excess Sludge Production from Activated Sludge Process of Sago Industry Wastewater Using Central Composite Design  

PubMed Central

Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent and to optimise the variables such as pH, ozonation time, and retention time. ANOVA showed that the coefficient determination value (R2) of VSS and COD reduction were 0.9689 and 0.8838, respectively. VSS reduction (81%) was achieved at acidic pH 6.9, 12 minutes ozonation, and retention time of 10 days. COD reduction (87%) was achieved at acidic pH 6.7, 8 minutes of ozonation time, and retention time of 6 days. Low ozonation time and high retention time influence maximum sludge reduction, whereas low ozonation time with low retention time was effective for COD reduction. PMID:22593666

Subha, B.; Muthukumar, M.



Selective hydrolysis of wastewater sludge Part 1, December 2008  

E-print Network

and cost benefit analysis for Esbjerg Vest wastewater treatment plant, Denmark PSO-F&U project nr. 2006-F&U projects having project number 2006-1-6815 . The project constitutes the phase 1, a cost-benefit analysis-1-681 5 Project by: Eurotec West A/S CVR. Nr.: 21 14 54 40 Report by : Niels Ã?stergaard, Eurotec West A


Distribution and characterization of anammox in a swine wastewater activated sludge facility.  


Anaerobic ammonium oxidation (anammox) is a novel biological nitrogen removal process that oxidizes NH4(+) to N2 with NO2(-) as an electron acceptor. The purpose of this study was to examine the potential activity and characteristics of anammox in a conventional swine wastewater treatment facility, which uses an activated sludge system consisting of three cascade aeration tanks equipped with ceramic support material. Anammox activity was estimated by a (15)N tracer assay method and was detected in all the sludge and biofilm samples in each aeration tank. Biofilm taken from the third aeration tank, in which the dissolved oxygen concentration was 7.5 mg/L and the wastewater included a high concentration of NO3(-), showed by far the highest anammox activity. A clone library analysis showed the existence of anammox bacteria closely related to 'Candidatus Jettenia asiatica' and 'Ca. Brocadia caroliniensis'. The optimum conditions for anammox activity were a pH of 6.7-7.2, a temperature of 35 °C, a NO2(-) concentration of 10 mmol/L or less, and an NH4(+) concentration of 32 mmol/L or less. PMID:23676406

Yamagishi, Takao; Takeuchi, Mio; Wakiya, Yuichiro; Waki, Miyoko



Iodine-131 levels in sludge and treated municipal wastewaters near a large medical complex.  

PubMed Central

Iodine-131 was found to dominate the gamma spectra of dried sludge and concentration liquid effluent samples from a sewage treatment plant serving the area containing the Texas Medical Center in 1975. The concentration of Iodine-131 varied considerably on a time scale of weeks but was fairly stable in the course of a single day. The partition of Iodine-131 between the dried sludge and the liquid effluent was found to be reasonably constant during the sampling period. Knowledge of the concentration in these phases and the daily output of sludge and effluent let to be estimate of an annual discharge of over one Curie of Iodine-131. Circumstantial evidence linking this discharge to the practice of nuclear medicine in the area is considered strong, but an attempt to correlate variation in the effluent activity with actual nuclide use was inconclusive due, among other reasons, to an insufficient clinical data base. An analysis of possible exposure pathway indicated that negligible human exposure resulted from the Iodine-131 released primarily because the receiving body of water is a saline industrial waterway. A more extensive analysis would be in order for a similar plant discharging treated wastewaters into an inland water system. PMID:7258430

Prichard, H M; Gesell, T F; Davis, E



An expert system for monitoring and diagnosis of anaerobic wastewater treatment plants.  


In this paper, an expert system (ES) developed for the monitoring and diagnosis of anaerobic wastewater treatment plants (AWT), is presented. The system was evaluated in a hybrid pilot plant of 1.1 m3 located in an industrial environment for the treatment of wastewaters from a fibreboard production factory. The reactor is a hybrid USBF, combining an upflow anaerobic sludge blanket (UASB) in the lower part and an upflow anaerobic filter (UAF) at the top. PMID:12153033

Puñal, A; Roca, E; Lema, J M



Systematical strategies for wastewater treatment and the generated wastes and greenhouse gases in China  

Microsoft Academic Search

China now faces double challenges of water resources shortage and severe water pollution. To resolve Chinese water pollution\\u000a problems and reduce its impacts on human health, economic growth and social development, the situation of wastewater treatment\\u000a was investigated. Excess sludge and greenhouse gases (GHGs) emitted during wastewater treatment were also surveyed. It is\\u000a concluded that Chinese water pollution problems should

Jingbo Guo; Fang Ma; Yuanyuan Qu; Ang Li; Liang Wang



EPA Science Inventory

The U.S. Environmental Protection Agency (USEPA) first issued detailed guidance on the design, construction, and operation of onsite wastewater treatment systems (OWTSs) in 1980. Design Manual: Onsite Wastewater Treatment and Disposal Systems (USEPA.1980) was the most comprehens...


Biodegradability and toxicity of pharmaceuticals in biological wastewater treatment plants.  


In this experimental study both biological treatability of pharmaceuticals and their potential toxic effect in biological processes were evaluated. The pharmaceuticals were selected among those that are present at higher concentration in the Italian wastewater treatment plant effluents and widely used as antiulcer (ranitidine), beta-blocker (atenolol) and antibiotic (lincomycin). The present paper is the continuation of a work already presented,[1] which used a synthetic wastewater fed to laboratory scale SBR (Sequencing Batch Reactor) operated with different sludge ages (8 and 14 days), different biochemical conditions (aerobic or anoxic-aerobic mode) and several influent drug concentrations (2, 3 and 5 mg/L). In this case a real municipal wastewater was used as influent to the SBR. In parallel, batch tests were conducted to determine the removal kinetics of drugs and nitrogen. Toxicity tests using a titrimetric biosensor to verify possible inhibition on microorganisms were also performed. Finally, the possible adsorption of the pharmaceuticals on activated sludge was evaluated. The drugs under investigation showed different behaviours in terms of both biodegradability and toxicity effect on nitrifiers. Ranitidine showed generally low removal efficiencies (17-26%) and a chronic inhibition on nitrification. Atenolol showed generally higher removal efficiencies than ranitidine, even if the fairly good efficiency obtained in the previous experimentation with synthetic wastewater (up to 90%) was not attained with real wastewater (36%). No inhibition on nitrification was observed on both acclimated and non acclimated microorganisms with a high nitrification activity, whilst it was present with activated sludge characterised by a lower nitrification activity. Consistently with his pharmaceutical properties, lincomycin showed significant inhibition on nitrification activity. PMID:16849129

Carucci, Alessandra; Cappai, Giovanna; Piredda, Martina



The influence of SBR parameters on the sludge toxicity of synthetic wastewater containing bisphenol A.  


Synthetic wastewater with bisphenol A (BPA) concentrations of 7.5, 20, and 40 mg/L was treated with activated sludge sequential batch reactors (SBRs). The sludge acute toxicity indicated by the inhibitory ratio to luminous bacteria T3 was evaluated. The influent COD was controlled at approximately 300 mg/L, and aerobic conditions were maintained in the SBR. It was found that the process of BPA biodegradation, as opposed to BPA adsorption, contributed to the formation of sludge toxicity; there was a positive relationship between sludge toxicity and influent BPA concentration, and the toxicity centralized in intracellular regions and the intersection of extracellular polymeric substances (EPS) in sludge flocs. Since the BPA biodegradation process dedicated to sludge toxicity, the influence of key operational parameters such as sludge retention time (SRT) and hydraulic retention time (HRT) on sludge toxicity were investigated. It was founded that sludge toxicity decreased significantly when SRT and HRT were shortened from 20 to 10 days and 12 to 8 h, respectively. The results of Pearson correlation analysis indicated that the Shannon index H of the bacterial community correlated significantly to sludge toxicity. The results from both similarity analysis and UPGMA indicated that influent quality characteristic contributes much more to bacterial community than operation parameters, and then leads to difference between blank and control sludge toxicity. PMID:24728543

Chen, Xiurong; Zhao, Jianguo; Zhao, Jun; Yang, Na; Zhang, Fei; Jiang, Zijian




E-print Network

94/0169 A STUDY OF ACTIVATED SLUDGE DEWATERING IN EXPERIMENTAL REED-PLANTED OR UNPLANTED SLUDGE study; reeds; sludge dewatering; sludge drying beds; small wastewater treatment plants. INTRODUCTION). It was of interest to confirm this aptitude for dewatering sludge from extended aeration plants, a medium

Paris-Sud XI, Université de


Bioelectrochemical enhancement of anaerobic methanogenesis for high organic load rate wastewater treatment in a up-flow anaerobic sludge blanket (UASB) reactor  

PubMed Central

A coupling process of anaerobic methanogenesis and electromethanogenesis was proposed to treat high organic load rate (OLR) wastewater. During the start-up stage, acetate removal efficiency of the electric-biological reactor (R1) reached the maximization about 19 percentage points higher than that of the control anaerobic reactor without electrodes (R2), and CH4 production rate of R1 also increased about 24.9% at the same time, while additional electric input was 1/1.17 of the extra obtained energy from methane. Coulombic efficiency and current recorded showed that anodic oxidation contributed a dominant part in degrading acetate when the metabolism of methanogens was low during the start-up stage. Along with prolonging operating time, aceticlastic methanogenesis gradually replaced anodic oxidation to become the main pathway of degrading acetate. When the methanogens were inhibited under the acidic conditions, anodic oxidation began to become the main pathway of acetate decomposition again, which ensured the reactor to maintain a stable performance. FISH analysis confirmed that the electric field imposed could enrich the H2/H+-utilizing methanogens around the cathode to help for reducing the acidity. This study demonstrated that an anaerobic digester with a pair of electrodes inserted to form a coupling system could enhance methanogenesis and reduce adverse impacts. PMID:25322701

Zhao, Zhiqiang; Zhang, Yaobin; Chen, Shuo; Quan, Xie; Yu, Qilin



Organic contaminants in onsite wastewater treatment systems  

USGS Publications Warehouse

Wastewater from thirty onsite wastewater treatment systems was sampled during a reconnaissance field study to quantify bulk parameters and the occurrence of organic wastewater contaminants including endocrine disrupting compounds in treatment systems representing a variety of wastewater sources and treatment processes and their receiving environments. Bulk parameters ranged in concentrations representative of the wide variety of wastewater sources (residential vs. non-residential). Organic contaminants such as sterols, surfactant metabolites, antimicrobial agents, stimulants, metal-chelating agents, and other consumer product chemicals, measured by gas chromatography/mass spectrometry were detected frequently in onsite system wastewater. Wastewater composition was unique between source type likely due to differences in source water and chemical usage. Removal efficiencies varied by engineered treatment type and physicochemical properties of the contaminant, resulting in discharge to the soil treatment unit at ecotoxicologically-relevant concentrations. Organic wastewater contaminants were detected less frequently and at lower concentrations in onsite system receiving environments. Understanding the occurrence and fate of organic wastewater contaminants in onsite wastewater treatment systems will aid in minimizing risk to ecological and human health.

Conn, K.E.; Siegrist, R.L.; Barber, L.B.; Brown, G.K.



Swine wastewater treatment in constructed wetlands  

Technology Transfer Automated Retrieval System (TEKTRAN)

One of the passive technologies being used for animal wastewater treatment is constructed wetlands. We have investigated swine lagoon wastewater treatment in both continuous marsh and marsh-pond-marsh (MPM) type constructed wetlands for their nitrogen treatment efficiency, ammonia volatilization, de...


Simulation of wastewater treatment by aerobic granules in a sequencing batch reactor based on cellular automata.  


In the present paper, aerobic granules were developed in a sequencing batch reactor (SBR) using synthetic wastewater, and 81 % of granular rate was obtained after 15-day cultivation. Aerobic granules have a 96 % BOD removal to the wastewater, and the reactor harbors a mount of biomass including bacteria, fungi and protozoa. In view of the complexity of kinetic behaviors of sludge and biological mechanisms of the granular SBR, a cellular automata model was established to simulate the process of wastewater treatment. The results indicate that the model not only visualized the complex adsorption and degradation process of aerobic granules, but also well described the BOD removal of wastewater and microbial growth in the reactor. Thus, CA model is suitable for simulation of synthetic wastewater treatment. This is the first report about dynamical and visual simulation of treatment process of synthetic wastewater in a granular SBR. PMID:24696379

Benzhai, Hai; Lei, Liu; Ge, Qin; Yuwan, Peng; Ping, Li; Qingxiang, Yang; Hailei, Wang




EPA Science Inventory

Twenty-eight lime stabilization facilities were visited. None of these plants were originally designed for sludge lime stabilization. Lime stabilization was instituted either as a permanent sludge handling mechanism to replace a more costly process, as an interim sludge handling ...


Impacts of Multiwalled Carbon Nanotubes on Nutrient Removal from Wastewater and Bacterial Community Structure in Activated Sludge  

PubMed Central

Background The increasing use of multiwalled carbon nanotubes (MWCNTs) will inevitably lead to the exposure of wastewater treatment facilities. However, knowledge of the impacts of MWCNTs on wastewater nutrient removal and bacterial community structure in the activated sludge process is sparse. Aims To investigate the effects of MWCNTs on wastewater nutrient removal, and bacterial community structure in activated sludge. Methods Three triplicate sequencing batch reactors (SBR) were exposed to wastewater which contained 0, 1, and 20 mg/L MWCNTs. MiSeq sequencing was used to investigate the bacterial community structures in activated sludge samples which were exposed to different concentrations of MWCNTs. Results Exposure to 1 and 20 mg/L MWCNTs had no acute (1 day) impact on nutrient removal from wastewater. After long-term (180 days) exposure to 1 mg/L MWCNTs, the average total nitrogen (TN) removal efficiency was not significantly affected. TN removal efficiency decreased from 84.0% to 71.9% after long-term effects of 20 mg/L MWCNTs. After long-term exposure to 1 and 20 mg/L MWCNTs, the total phosphorus removal efficiencies decreased from 96.8% to 52.3% and from 98.2% to 34.0% respectively. Further study revealed that long-term exposure to 20 mg/L MWCNTs inhibited activities of ammonia monooxygenase and nitrite oxidoreductase. Long-term exposure to 1 and 20 mg/L MWCNTs both inhibited activities of exopolyphosphatase and polyphosphate kinase. MiSeq sequencing data indicated that 20 mg/L MWCNTs significantly decreased the diversity of bacterial community in activated sludge. Long-term exposure to 1 and 20 mg/L MWCNTs differentially decreased the abundance of nitrifying bacteria, especially ammonia-oxidizing bacteria. The abundance of PAOs was decreased after long-term exposure to 20 mg/L MWCNTs. The abundance of glycogen accumulating organisms (GAOs) was increased after long-term exposure to 1 mg/L MWCNTs. Conclusion MWCNTs have adverse effects on biological wastewater nutrient removal, and altered the diversity and structure of bacterial community in activated sludge. PMID:25238404

Hai, Reti; Wang, Yulin; Wang, Xiaohui; Du, Zhize; Li, Yuan



Large area radiation source for water and wastewater treatment  

NASA Astrophysics Data System (ADS)

There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh



Floating treatment wetlands for domestic wastewater treatment.  


Floating islands are a form of treatment wetland characterized by a mat of synthetic matrix at the water surface into which macrophytes can be planted and through which water passes. We evaluated two matrix materials for treating domestic wastewater, recycled plastic and recycled carpet fibers, for chemical oxygen demand (COD) and nitrogen removal. These materials were compared to pea gravel or open water (control). Experiments were conducted in laboratory scale columns fed with synthetic wastewater containing COD, organic and inorganic nitrogen, and mineral salts. Columns were unplanted, naturally inoculated, and operated in batch mode with continuous recirculation and aeration. COD was efficiently removed in all systems examined (>90% removal). Ammonia was efficiently removed by nitrification. Removal of total dissolved N was ?50% by day 28, by which time most remaining nitrogen was present as NO(3)-N. Complete removal of NO(3)-N by denitrification was accomplished by dosing columns with molasses. Microbial communities of interest were visualized with denaturing gradient gel electrophoresis (DGGE) by targeting specific functional genes. Shifts in the denitrifying community were observed post-molasses addition, when nitrate levels decreased. The conditioning time for reliable nitrification was determined to be approximately three months. These results suggest that floating treatment wetlands are a viable alternative for domestic wastewater treatment. PMID:22105133

Faulwetter, J L; Burr, M D; Cunningham, A B; Stewart, F M; Camper, A K; Stein, O R



Denitrification of high nitrate wastewater in a cloth strip bioreactor with immobilized sludge.  


Denitrification of synthetic high nitrate wastewater containing 40,000 ppm NO(3) (9,032 ppm NO(3)-N) was achieved using immobilized activated sludge in a column reactor. Active anoxic sludge adsorbed onto Terry cloth was used in the denitrification of high nitrate wastewater. The operational stability of the immobilized sludge system was studied both in a batch reactor and in a continuous reactor. The immobilized sludge showed complete degradation of different concentrations of NO(3)-N (1,129, 1,693, 3,387, 6,774, and 9,032 ppm) in a batch process. The reactors were successfully run for 90 days without any loss in activity. The immobilized cell process has yielded promising results in attaining high denitrifying efficiency. PMID:22832944

Nair, Rashmi R; D'Souza, Stanislaus F



Recovering and recycling Hg from chlor-alkali plant wastewater sludge  

NASA Astrophysics Data System (ADS)

Montana Tech of the University of Montana and Universal Dynamics of British Columbia have developed a hydrometallurgical process for recovering and recycling mercury from chlorine plant wastewater sludge materials (U.S. Environmental Protection Agency [EPA]hazardous-waste classification K106). The hydrometallurgical process is also applicable for the treatment of mercury-contaminated soils (EPA hazardous waste classification D009) and other mercury-bearing waste materials. The process, which is capable of lowering the mercury content in the K106 solids from 10% to <50 mg/kg Hg, has been commercialized and utilized at three U.S. plants. This paper describes the fundamental chemistry of the process, the flowsheet being used, and operating plant case histories.

Twidwell, L. G.; Thompson, R. J.



Conventional approach for abattoir wastewater treatment.  


Detailed physico-chemical studies on abattoir effluent using lime, alum, ferrous sulphate and an anionic polyelectrolyte were tried individually and in combination. Among the coagulants tried, lime resulted in good settling of the sludge. At 400 mg l(-1) of lime dose, the Suspended Solids (SS), Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removals were found to be 41.9%, 38.9% and 36.1%, respectively. Best results were obtained with lime and ferrous sulphate in a combination ratio of 400:100 mg l(-1), and the COD reduction of 36.1% at 400 mg l(-1) of lime, further improved to 56.8%. Lime and alum dose of 400:50 mg l(-1) resulted in an increased COD reduction of 42.6% compared to 36.1% at lime dose of 400 mg l(-1). However, the same lime dose with ferrous sulphate addition of 100 mg l(-1) resulted in an increased COD reduction of 56.8% compared to 36.1%. This is a more efficient option for abattoir wastewater treatment and also cost effective. Ferrous sulphate with anionic polyelectrolyte resulted in good removals. Though it is a costly chemical, the dose needed is just half that of lime and just 0.1 mg l(-1) of anionic polyelectrolyte resulted in good reductions in SS, BOD and COD of 54.2%, 49.6% and 43.8% respectively. Studies indicated that the lime and ferrous sulphate in the combination of 400:100 mg l(-1), and ferrous sulphate and polyelectrolyte in the combination of 100:0.1 mg l(-1) are the two feasible options. Lime in combination with alum can also be applied but resultant sludge volume would be more. PMID:15906496

Satyanarayan, S; Ramakant; Vanerkar, A P



Quantitative mapping of suspended solids in wastewater sludge plumes in the New York Bight apex  

NASA Technical Reports Server (NTRS)

The purpose of this investigation was to apply the previously reported methodology to remotely sensed data that were collected over wastewater sludge plumes in the New York Bight apex on September 22, 1975. Spectral signatures were also determined during this study. These signatures may be useful in the specific identification of sludge plumes, as opposed to other plumes such as those created by the disposal of industrial acid wastes.

Johnson, R. W.; Duedall, I. W.; Glasgow, R. M.; Proni, J. R.; Nelsen, T. A.



The application of molecular techniques to the study of wastewater treatment systems.  


Wastewater treatment systems tend to be engineered to select for a few functional microbial groups that may be organized in various spatial structures such as activated sludge flocs, biofilm or granules and represented by single coherent phylogenic groups such as ammonia-oxidizing bacteria (AOB) and polyphosphate-accumulating organisms (PAO). In order to monitor and control engineered microbial structure in wastewater treatment systems, it is necessary to understand the relationships between the microbial community structure and the process performance. This review focuses on bacterial communities in wastewater treatment processes, the quantity of microorganisms and structure of microbial consortia in wastewater treatment bioreactors. The review shows that the application of molecular techniques in studies of engineered environmental systems has increased our insight into the vast diversity and interaction of microorganisms present in wastewater treatment systems. PMID:19882286

Wojnowska-Bary?a, Irena; Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena



The Application of Molecular Techniques to the Study of Wastewater Treatment Systems  

NASA Astrophysics Data System (ADS)

Wastewater treatment systems tend to be engineered to select for a few functional microbial groups that may be organized in various spatial structures such as activated sludge flocs, biofilm or granules and represented by single coherent phylogenic groups such as ammonia-oxidizing bacteria (AOB) and polyphosphate-accumulating organisms (PAO). In order to monitor and control engineered microbial structure in wastewater treatment systems, it is necessary to understand the relationships between the microbial community structure and the process performance. This review focuses on bacterial communities in wastewater treatment processes, the quantity of microorganisms and structure of microbial consortia in wastewater treatment bioreactors. The review shows that the application of molecular techniques in studies of engineered environmental systems has increased our insight into the vast diversity and interaction of microorganisms present in wastewater treatment systems.

Wojnowska-Bary?a, Irena; Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena


Occurrence of denitrifying phosphorus removing bacteria in modified UCT-type wastewater treatment plants  

Microsoft Academic Search

The occurrence of denitrifying phosphorus removing bacteria (DPB) and the contribution of DPB to phosphorus removal in full-scale wastewater treatment plants (WWTPs) has been investigated by batch tests with the activated sludge from two WWTPs (WWTP-Genemuiden and -Holten). Both WWTPs are operated as UCT-type processes. Batch tests to evaluate the biomass composition of the sludges were developed. These batch tests

T. Kuba; M. C. M. Van Loosdrecht; F. A. Brandse; J. J. Heijnen



Improved biological treatment of nitrogen-deficient wastewater by incorporation of N 2 -fixing bacteria  

Microsoft Academic Search

The N2-fixing bacterium, Azotobacter vinelandii, was used both in single culture and in combination with activated sludge culture for the treatment of nitrogen-deficient wastewaters as an alternative to external nitrogen supplementation. Azotobacter-supplemented activated sludge culture removed more total organic carbon (TOC), especially at low initial TN\\/COD (total nitrogen\\/chemical oxygen demand) ratios, than the Azotobacter-free culture. Up to 95% TOC removal

Fikret Kargi; Serpil Özm?hç?



A practitioner's perspective on the uses and future developments for wastewater treatment modelling.  


The modern age of wastewater treatment modelling began with publication of the International Water Association (IWA) Activated Sludge Model (ASM) No.1 and has advanced significantly since. Models are schematic representations of systems that are useful for analysis to support decision-making. The most appropriate model for a particular application often incorporates only those components essential for the particular analyses to be performed (i.e. the simplest model possible). Characteristics of effective models are presented, along with how wastewater modelling is integrated into the wastewater project life cycle. The desirable characteristics of wastewater treatment modelling platforms are then reviewed. Current developments of note in wastewater treatment modelling practice include estimates of greenhouse gas emissions, incorporating uncertainty into wastewater modelling and design practice, more fundamental modelling of process chemistry, and improved understanding of the degradability of wastewater constituents in different environments. Areas requiring greater emphasis include increased use of metabolic modelling, characterisation of the hydrodynamics of suspended and biofilm biological treatment processes, and the integration of biofilm and suspended growth process modelling. Wastewater treatment models must also interface with water and wastewater management software packages. While wastewater treatment modelling will continue to advance and make important contributions to practice, it must be remembered that these are complex systems which exhibit counter-intuitive behaviour (results differ from initial expectations) and multiple dynamic steady-states which can abruptly transition from one to another. PMID:21278475

Daigger, G T



Hazardous solid waste from domestic wastewater treatment plants.  

PubMed Central

The treatment of liquid wastes in municipal sewage treatment plants creates significant quantities of solid residue for disposal. The potential hazard from these wastes requires that their characteristics be determined accurately to develop environmentally sound management criteria. It is readily recognized that the sludge characteristics vary with the type and degree of industrial activity within a wastewater collection system and that these characteristics play a significant role in determining whether the material has potential for beneficial reuse or if it must be directed to final disposal. This paper offers an overview of past and present practices of sewage sludge disposal, an indication of quantities produced, and experience with beneficial reuse. An estimated range of costs involved, expected environmental effects and potential for continued use is offered for each disposal or reuse system discussed. PMID:738239

Harrington, W M



Making wastewater environmentally sustainable: Innovative technology offers new possibilities for wastewater treatment  

E-print Network

Story by Katie Heinrich 16 tx H2O Summer 2013 Making wastewater environmentally sustainable Innovative technology o#30;ers new possibilities for wastewater treatment Municipal wastewater treatment plants may soon become more sustainable...

Heinrich, Katie



Struvite formation for enhanced dewaterability of digested wastewater sludge.  


One of the main advantages of controlled struvite formation in digested sludge is an improvement in dewaterability of the digested sludge, which eventually leads to lower volumes of dewatered sludge that need to be transported. The effects of the control parameters for struvite formation, magnesium concentration and pH, on digested sludge dewaterability were investigated and are discussed in relation to the efficiency of struvite formation. Laboratory experiments with digested activated sludge were performed in a 20 L batch reactor. CO2 was stripped from the digested sludge using a bubble aerator and magnesium chloride was added to induce struvite formation. The dewaterability of the sludge was determined by gravity filtration tests. In the experiments, either the pH or the molar magnesium to phosphate ratio (Mg:PO4) was varied. The results confirm improved sludge dewaterability after struvite formation. Magnesium to phosphate ratios above 1.0 mol/mol did not further improve dewaterability. The addition of magnesium did not prevent the need for polymer addition for sludge dewatering. An increase in pH led to a deterioration in dewaterability. The best dewaterability results were found at the lowest pH value (pH = 7.0), while stirring the sludge instead of using the bubble aerator. At these settings, an orthophosphate removal of around 80% was achieved. PMID:24645433

Bergmans, B J C; Veltman, A M; van Loosdrecht, M C M; van Lier, J B; Rietveld, L C



Color removal from cotton textile industry wastewater in an activated sludge system with various additives.  


The low biodegradability of many dyes and textile chemicals indicates that biological treatment is not always successful in the treatment of cotton textile wastewater, in terms of color removal. In this study, a specific organic flocculant (Marwichem DEC), powdered activated carbon (PAC), bentonite, activated clay and commercial synthetic inorganic clay (Macrosorb) were directly added into the activated sludge laboratory pilot plant model. Before dosage, the optimum sludge retention time and hydraulic retention time were determined as 30 days and 1.6 days, respectively. The Monod kinetic constants were determined as Y = 0.76 kg MLSS/kg COD, Kd = 0.026 l/day, K(S) = 113.3 mg/L, k = 0.42 l/day and mu(max) = 0.32 kg MLSS/kg COD day. Under these conditions the average COD removal was 94% and color removal was 36%. The addition of these materials did not change COD removal significantly. The most effective materials were found to be DEC and PAC for color removal. While the color removal efficiency for 120 mg/L DEC addition was 78%, it was 65% for 100 mg/L, 77% for 200 mg/L and 86% for 400 mg/L PAC addition. The advantage of DEC compared to PAC was the lower sludge production. Statistical analyses using multiple linear regression indicate that there is no relationship between the effluent color with the influent color and total suspended solids (TSS) for DEC and PAC addition. On the other hand, when only bentonite, activated clay and Macrosorb were added, the effluent color was primarily dependent on the influent color and the TSS concentration had little effect. When the data is examined by using Kruskal-Wallis H and Mann-Whitney U tests and it was found that there was a significant difference between the color data groups. PMID:12146882

Pala, Ay?egül; Tokat, Enis



On-Site Wastewater Treatment Systems: Constructed Wetland Media  

E-print Network

the pores - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - On-site wastewater treatment systems Figure 1: A subsurface flow constructed wetland system for residential wastewater treatment. Constructed wetland media Bruce...

Lesikar, Bruce J.; Weaver, Richard; Richter, Amanda; O'Neill, Courtney



High rate aerobic treatment of brewery wastewater using the jet loop reactor  

Microsoft Academic Search

An aerobic Jet Loop Reactor (JLR) activated sludge process of 541. volume was used to investigate its suitability for the treatment of industrial wastewaters, specifically brewery wastewater. A loading rate of 50 kg COD\\/m3·d was achieved with 97% COD removal for a period of 5 weeks and although the settleability was found to be acceptable non-flocculating motile bacteria caused the

James C. Bloor; G. K. Anderson; A. R. Willey



Simulation study supporting wastewater treatment plant upgrading.  


The paper presents a study where upgrading of an existing wastewater treatment plant was supported by simulation. The aim of the work was to decide between two technologies to improve nitrogen removal: a conventional activated sludge process (ASP) and a moving bed biofilm reactor (MBBR). To perform simulations, the mathematical models of both processes were designed. The models were calibrated based on data from ASP and MBBR pilot plants operating in parallel on the existing plant. Only two kinetic parameters needed to be adjusted to represent the real plant behaviour. Steady-state analyses have shown a similar efficiency of both processes in relation to carbon removal, but improved performance of MBBR in relation to nitrogen removal. Better performance of MBBR can be expected especially at low temperatures. Simulations have not confirmed the expected less volume required for the MBBR process. Finally, the MBBR was chosen for plant upgrading. The developed process model will be further used to evaluate the final plant configuration and to optimise the plant operating parameters. PMID:12361028

Hvala, N; Vrecko, D; Burica, O; Strazar, M; Levstek, M



K Basin sludge treatment process description  

SciTech Connect

The K East (KE) and K West (KW) fuel storage basins at the 100 K Area of the Hanford Site contain sludge on the floor, in pits, and inside fuel storage canisters. The major sources of the sludge are corrosion of the fuel elements and steel structures in the basin, sand intrusion from outside the buildings, and degradation of the structural concrete that forms the basins. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be treated so that it meets Tank Waste Remediation System (TWRS) acceptance criteria and can be sent to one of the double-shell waste tanks. The US Department of Energy, Richland Operations Office accepted a recommendation by Fluor Daniel Hanford, Inc., to chemically treat the sludge. Sludge treatment will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and reacting the solution with caustic to co-precipitate the uranium and plutonium. A truck will transport the resulting slurry to an underground storage tank (most likely tank 241-AW-105). The undissolved solids will be treated to reduce the transuranic (TRU) and content, stabilized in grout, and transferred to the Environmental Restoration Disposal Facility (ERDF) for disposal. This document describes a process for dissolving the sludge to produce waste streams that meet the TWRS acceptance criteria for disposal to an underground waste tank and the ERDF acceptance criteria for disposal of solid waste. The process described is based on a series of engineering studies and laboratory tests outlined in the testing strategy document (Flament 1998).

Westra, A.G.



Quantification of greenhouse gas emissions from sludge treatment wetlands.  


Constructed wetlands are nowadays successfully employed as an alternative technology for wastewater and sewage sludge treatment. In these systems organic matter and nutrients are transformed and removed by a variety of microbial reaction and gaseous compounds such as methane (CH(4)) and nitrous oxide (N(2)O) may be released to the atmosphere. The aim of this work is to introduce a method to determine greenhouse gas emissions from sludge treatment wetlands (STW) and use the method in a full-scale system. Sampling and analysing techniques used to determine greenhouse gas emissions from croplands and natural wetlands were successfully adapted to the quantification of CH(4) and N(2)O emissions from an STW. Gas emissions were measured using the static chamber technique in 9 points of the STW during 13 days. The spatial variation in the emission along the wetland did not follow some specific pattern found for the temporal variation in the fluxes. Emissions ranged from 10 to 5400 mg CH(4)/m(2)d and from 20 to 950 mgN(2)O/m(2)d, depending on the feeding events. The comparison between the CH(4) and N(2)O emissions of different sludge management options shows that STW have the lowest atmospheric impact in terms of CO(2) equivalent emissions (Global warming potential with time horizon of 100 years): 17 kg CO(2) eq/PE y for STW, 36 kg CO(2) eq/PE y for centrifuge and 162 kg CO(2) eq/PE y for untreated sludge transport, PE means Population Equivalent. PMID:22280953

Uggetti, Enrica; García, Joan; Lind, Saara E; Martikainen, Pertti J; Ferrer, Ivet



Biodegradation of olive mill wastewater sludge by its co-composting with agricultural wastes  

Microsoft Academic Search

The use of maize straw (MS) or cotton waste (CW) as bulking agents in the composting of olive mill wastewater (OMW) sludge was compared by studying the organic matter (OM) mineralisation and humification processes during composting and the characteristics of the end products. Both composts were prepared in a pilot-plant using the Rutgers static-pile system. The use of CW instead

C Paredes; M. P Bernal; J Cegarra; A Roig




EPA Science Inventory

This study involved the development and validation of analytical methods for determining aniline and 18 halogen and nitro-substituted derivatives in industrial wastewater and municipal sludge. Gas chromatography (GC) with a nitrogen-phosphorus detector (NPD) was found to be well ...



EPA Science Inventory

Emissions of metals and organics from a series of four wastewater sludge incinerators were determined. hree multiple hearth units and one fluidized bed combustor were tested. missions were controlled with a combination of venturi and/or tray impingement scrubbers. ne site incorpo...



EPA Science Inventory

The object of this work was to compare and analyze heavy metal emissions associated with the thermal conversion (incineration) processes which can be conducted in a multiple-hearth furnace to dry municipal wastewater (sewage) sludge and reduce its volume by forming an ash or char...


Speciation of heavy metals in untreated domestic wastewater sludge by time saving BCR sequential extraction method  

Microsoft Academic Search

In this work the modified three-stage sequential extraction procedure developed within the Standards, Measurement and Testing Programme (formally the Community Bureau of Reference BCR) of the European Commission, was applied for the fractionation of Cd, Cr, Cu, Ni, Pb and Zn in the untreated domestic wastewater sludge (DWS) collected from the Hyderabad city of Pakistan. The aim of our study

Mohammad K. Jamali; Tasneem G. Kazi; Hassan I. Afridi; Mohammad B. Arain; Nusrat Jalbani; Attique R. Memon



Novel bioevaporation process for the zero-discharge treatment of highly concentrated organic wastewater.  


A novel process termed as bioevaporation was established to completely evaporate wastewater by metabolic heat released from the aerobic microbial degradation of the organic matters contained in the highly concentrated organic wastewater itself. By adding the glucose solution and ground food waste (FW) into the biodried sludge bed, the activity of the microorganisms in the biodried sludge was stimulated and the water in the glucose solution and FW was evaporated. As the biodegradable volatile solids (BVS) concentration in wastewater increased, more heat was produced and the water removal ratio increased. When the volatile solids (VS) concentrations of both glucose and ground FW were 120 g L(-1), 101.7% and 104.3% of the added water was removed, respectively, by completely consuming the glucose and FW BVS. Therefore, the complete removal of water and biodegradable organic contents was achieved simultaneously in the bioevaporation process, which accomplished zero-discharge treatment of highly concentrated organic wastewater. PMID:23886540

Yang, Benqin; Zhang, Lei; Lee, Yongwoo; Jahng, Deokjin



LAS homolog distribution shift during wastewater treatment and composting ecological implications  

SciTech Connect

The behavior of LAS (linear alkylbenzene sulfonate) in different environmental compartments was studied through wastewater treatment process steps in sewage treatment plants of Alicante and Benidorm (activated sludge type) as well as in Guardamar (lagoons). The fate of LAS, using a specific HPLC method, was monitored during treatment sludge compostage and soil amendment operations. Finally, the marine sediments close to a submarine wastewater sewer outfall were analyzed. The results show significant differences between distribution of LAS homologs in water and solids (sludges, sediments, and soils), as compared to the original distribution in detergent formulations, yielding a lower LAS average molecular weight in water samples. The change observed in the homolog distribution of LAS implies a reduction in the toxicity to Daphnia, because a lower average molecular weight of LAS is less toxic.

Prats, D.; Ruiz, F.; Vazquez, B.; Zarzo, D. (Univ. of Alicante (Spain). Div. Chemical Engineering); Berna, J.L.; Moreno, A. (Petresa, Madrid (Spain))



The use of the anaerobic baffled reactor (ABR) for wastewater treatment: a review  

Microsoft Academic Search

A review concerning the development, applicability and possible future application of the anaerobic baffled reactor for wastewater treatment is presented. The reactor design has been developed since the early 1980s and has several advantages over well established systems such as the upflow anaerobic sludge blanket and the anaerobic filter. These include: better resilience to hydraulic and organic shock loadings, longer

William P. Barber; David C. Stuckey



Environmental and cost life cycle assessment of disinfection options for municipal wastewater treatment  

EPA Science Inventory

This document summarizes the data collection, analysis, and results for a base case wastewater treatment (WWT) plant reference model. The base case is modeled after the Metropolitan Sewer District of Greater Cincinnati (MSDGC) Mill Creek Plant. The plant has an activated sludge s...


DAI-DEPUR: an integrated and distributed architecture for wastewater treatment plants supervision  

Microsoft Academic Search

The activated sludge process -the main biological technology usually applied to wastewater treatment plants (WWTP)- directly depends on live beings (microorganisms), and therefore, on unforeseen changes experimented by them. It could be possible to get a good plant operation if the supervisory control system is able to react to the changes and deviations of the system and can take the

Miquel Sànchez-marrè; Ulises Cortés; Javier Lafuente; Ignasi Rodríguez-roda; Manel Poch



Jar Test. Operational Control Tests for Wastewater Treatment Facilities. Instructor's Manual [and] Student Workbook.  

ERIC Educational Resources Information Center

The jar test is used to determine the proper chemical dosage required for good coagulation and flocculation of water. The test is commonly used in potable water, secondary effluent prior to advanced wastewater treatment, secondary clarifier influent, and sludge conditioning practice. Designed for individuals who have completed National Pollutant…

Arasmith, E. E.


Evidence for Tin Inhibition of Enhanced Biological Phosphorus Removal at a Municipal Wastewater Treatment Plant  

Microsoft Academic Search

Concentrations of 34 metals were determined in the concentrated waste activated sludge from a dissolved air flotation unit at an advanced municipal wastewater treatment plant (WWTP) with biological nutrient removal. Reduction in enhanced biological phosphorus removal (EBPR) efficiency was observed at total tin concentrations greater than 4 ?g L in the solids fraction of the mixed liquor suspended solids. No

Sierra Rayne; Sheila Carey; Kaya Forest



Comparative effectiveness of engineered wetland systems in the treatment of anaerobically pre-treated domestic wastewater  

Microsoft Academic Search

A study was carried out to assess the effectiveness of engineered wetland systems (EWSs) in the treatment of domestic wastewater pre-treated in an upflow anaerobic sludge blanket (UASB) reactor in the tropics. Relative advantages of using different wetland plants were also assessed. The EWS had three units using river sand media. One bed was left unplanted and used as a

Stephen E. Mbuligwe




EPA Science Inventory

Constructed wetlands are man-made wastewater treatment systems. They usually have one or more cells less than 1 meter deep and are planted with aquatic greenery. Water outlet structures control the flow of wastewater through the system to keep detention times and water levels at ...



Microsoft Academic Search

Sanitary sewer systems and sewage treatment plants have been under construction aggressively in Taiwan. Interceptive sewer systems are popular in municipal areas to collect the wastewater from the existing sewage channels. The collected primary sludge (PS) attains special characteristics in the sewage treatment plant. The low volatile suspended solids\\/suspended solids ratio of only 0.4 to 0.5 is attributed to the

Sheng-Shung Cheng; Akiyoshi Ohashi; Horisawa Kotaro; Yu-Min Tien; Keng-Hao Yang


Adsorption behavior of sulfamethazine in an activated sludge process treating swine wastewater.  


Swine wastewater is an important pollution source of antibiotics entering the aquatic environment. In this work, the adsorption behavior of sulfamethazine (SMN), a commonly-used sulfonamide antibiotic, on activated sludge from a sequencing batch reactor treating swine wastewater was investigated. The results show that the adsorption of SMN on activated sludge was an initially rapid process and reached equilibrium after 6hr. The removal efficiency of SMN from the water phase increased with an increasing concentration of mixed liquor suspended solids, while the adsorbed concentration of SMN decreased. Solution pH influenced both the speciation of SMN and the surface properties of activated sludge, thus significantly impacting the adsorption process. A linear partition model could give a good fit for the equilibrium concentrations of SMN at the test temperatures (i.e., 10, 20 and 30°C). The partition coefficient (Kd) was determined to be 100.5L/kg at 20°C, indicating a quite high adsorption capacity for SMN. Thermodynamic analysis revealed that SMN adsorption on activated sludge was an exothermic process. This study could help to clarify the fate and behavior of sulfonamide antibiotics in the activated sludge process and assess consequent environmental risks arising from sludge disposal as well. PMID:25108718

Ben, Weiwei; Qiang, Zhimin; Yin, Xiaowei; Qu, Jiuhui; Pan, Xun



Anaerobic treatment of sulphate-rich wastewaters  

Microsoft Academic Search

Until recently, biological treatment of sulphate-rich wastewater was rather unpopular because of the production of H2S under anaerobic conditions. Gaseous and dissolved sulphides cause physical-chemical (corrosion, odour, increased effluent chemical oxygen demand) or biological (toxicity) constraints, which may lead to process failure. Anaerobic treatment of sulphate-rich wastewater can nevertheless be applied successfully provided a proper treatment strategy is selected. The

Look W. Hulshoff Pol; Piet N. L. Lens; Alfons J. M. Stams; Gatze Lettinga



Sludge ash as lightweight concrete material  

Microsoft Academic Search

Sludge is an inevitable by-product of wastewater treatment. Its abundance poses disposal problems that can be drastically reduced if sludge can be converted for economical uses in construction as substitute materials. Digested and dewatered sludge, after incineration at a high temperature, yields a hard, cellular, porous mass with low unit weight. This hardened mass of sludge ash can be crushed

Joo-Hwa Tay; Woon-Kwong Yip



Primary Treatment and Sludge Digestion Workshop.  

ERIC Educational Resources Information Center

This manual was developed for use at workshops designed to upgrade the knowledge of experienced wastewater treatment plant operators. Each of the sixteen lessons has clearly stated behavioral objectives to tell the trainee what he should know or do after completing that topic. Areas covered in this manual include: sewage characteristics;…

Ontario Ministry of the Environment, Toronto.


Heterogeneous catalytic ozonation of biologically pretreated Lurgi coal gasification wastewater using sewage sludge based activated carbon supported manganese and ferric oxides as catalysts.  


Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl? as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application. PMID:24907577

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




EPA Science Inventory

Pathogens can enter municipal wastewaters from several sources including homes, hospitals and slaughter houses. They are identified, typical levels found in sludges are given along with infectious doses, and their survival on crops and in the soil presented. As wastewater is clea...



EPA Science Inventory

The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion was the major factor infl...


Toward energy-neutral wastewater treatment: A high-rate contact stabilization process to maximally recover sewage organics.  


The conventional activated sludge process is widely used for wastewater treatment, but to progress toward energy self-sufficiency, the wastewater treatment scheme needs to radically improve energy balances. We developed a high-rate contact stabilization (HiCS) reactor system at high sludge-specific loading rates (>2kgbCODkg(-1)TSSd(-1)) and low sludge retention times (<1.2d) and demonstrate that it is able to recover more chemical energy from wastewater organics than high-rate conventional activated sludge (HiCAS) and the low-rate variants of HiCS and HiCAS. The best HiCS system recovered 36% of the influent chemical energy as methane, due to the combined effects of low production of CO2, high sludge yield, and high methane yield of the produced sludge. The HiCS system imposed a feast-famine cycle and a putative selection pressure on the sludge micro-organisms toward substrate adsorption and storage. Given further optimization, it is a promising process for energy recovery from wastewater. PMID:25553568

Meerburg, Francis A; Boon, Nico; Van Winckel, Tim; Vercamer, Jensen A R; Nopens, Ingmar; Vlaeminck, Siegfried E



Optimization of co-digestion of various industrial sludges for biogas production and sludge treatment: methane production potential experiments and modeling.  


Optimal biogas production and sludge treatment were studied by co-digestion experiments and modeling using five different wastewater sludges generated from paper, chemical, petrochemical, automobile, and food processing industries situated in Ulsan Industrial Complex, Ulsan, South Korea. The biomethane production potential test was conducted in simplex-centroid mixture design, fitted to regression equation, and some optimal co-digestion scenarios were given by combined desirability function based multi-objective optimization technique for both methane yield and the quantity of sludge digested. The co-digestion model incorporating main and interaction effects among sludges were utilized to predict the maximum possible methane yield. The optimization routine for methane production with different industrial sludges in batches were repeated with the left-over sludge of earlier cycle, till all sludges have been completely treated. Among the possible scenarios, a maximum methane yield of 1161.53 m(3) is anticipated in three batches followed by 1130.33 m(3) and 1045.65 m(3) in five and two batches, respectively. This study shows a scientific approach to find a practical solution to utilize diverse industrial sludges in both treatment and biogas production perspectives. PMID:24070651

Mahanty, Biswanath; Zafar, Mohd; Han, Man Jae; Park, Hung-Suck




EPA Science Inventory

A policy to develop water-quality-based permit limitations for toxic pollutants entering treatment plants is being developed because, even with efficient removal of conventional pollutants, significant amounts of toxic substances are being discharged through the Nation's wastewat...


Water/Wastewater Treatment Plant Operator Qualifications.  

ERIC Educational Resources Information Center

This article summarizes in tabular form the U.S. and Canadian programs for classification of water and wastewater treatment plant personnel. Included are main characteristics of the programs, educational and experience requirements, and indications of requirement substitutions. (CS)

Water and Sewage Works, 1979




EPA Science Inventory

The technology assessment provides an introduction to the use of several alternative energy sources at wastewater treatment plants. The report contains fact sheets (technical descriptions) and data sheets (cost and design information) for the technologies. Cost figures and schema...


Biohydrogen production and wastewater treatment from organic wastewater by anaerobic fermentation with UASB  

NASA Astrophysics Data System (ADS)

In order to discuss the ability of H2-production and wastewater treatment, an up-flow anaerobic sludge bed (UASB) using a synthesized substrate with brown sugar wastewater was conducted to investigate the hydrogen yield, hydrogen producing rate, fermentation type of biohydrogen production, and the chemical oxygen demand (COD) removal rate, respectively. The results show that when the biomass of inoculants was 22.5 g SS?L-1 and the influent concentration, hydraulic retention time (HRT) and initial pH were within the ranges of 4000˜6000 mg COD?L-1, 8 h and 5-5.5, respectively, and the biohydrogen producing reactor could work effectively. The maximum hydrogen production rate is 5.98 L?d-1. Simultaneously, the concentration of ethanol and acetic acid is around 80% of the aqueous terminal production in the system, which presents the typical ethanol type fermentation. pH is at the range of 4˜4.5 during the whole performing process, however, the removal rate of COD is just about 20%. Therefore, it's still needs further research to successfully achieve the biohydrogen production and wastewater treatment, simultaneously.

Wang, Lu; Li, Yong-feng; Wang, Yi-xuan; Yang, Chuan-ping



Wastewater treatment: Dye and pigment industry. (Latest citations from the Selected Water Resources Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning treatment of wastewater containing dyes and pigments. The citations discuss the of dyes and pigments in wastewater treatment systems, biodegradation of dyes, absorption and adsorption processes to remove dyes from wastewater, environmental effects from the disposal of dye-containing wastes, and methods of analysis for dyes in waste streams. Treatment methods such as ozonation, reverse osmosis, activated charcoal filtration, activated sludge, electrochemical treatments, thermal treatments, simple filtration, and absorption media are included. (Contains a minimum of 112 citations and includes a subject term index and title list.)

Not Available



Production of Electricity during Wastewater Treatment Using a  

E-print Network

Production of Electricity during Wastewater Treatment Using a Single Chamber Microbial Fuel Cell H wastewater, while at the same time accomplishing biological wastewater treatment (removal of chemical oxygen approach to wastewater treatment. If power generation in these systems can be increased, MFC technology may


Computing the Resilience of a Wastewater Treatment Bioreactor Nabil Mabrouk  

E-print Network

Computing the Resilience of a Wastewater Treatment Bioreactor Nabil Mabrouk Laboratory Abstract--Biological wastewater treatment reactor are de- signed to reduce wastewater treatment reactors are often subject to unexpected perturba- tions (variations in wastewater flow

Paris-Sud XI, Université de


Effect of plant species on water quality at the outlet of a sludge treatment wetland.  


Sludge treatment wetlands are mainly used to reduce the volume of activated sludge, and the pollutants at the outlet are generally returned to the wastewater treatment plant. However, in cases where sludges are produced far from treatment plants not only must the sludge be treated, but the discharge of pollutants into the surrounding environment must also be limited. The aim of this study was to evaluate the efficiency of different plant species in optimising pollutant removal in a decentralised sludge treatment wetland. In addition, a new system design was assessed, in which the wetland was not completely drained, and a saturated layer was created using an overflow. The experimental setup consisted of 16 mesocosms in total, planted with monocultures of Phragmites australis, Typha angustifolia and Scirpus fluviatilis, and unplanted controls, each in four replicates. The experiment was conducted during the third summer of operation after setup. The system was fed with highly concentrated fish farm sludge at a load of 30 kg of total solids m(-2) yr(-1). Results showed that such wetlands were highly efficient, with removal rates between 94% and 99% for most pollutants. Planted systems generally outperformed the unplanted control, with a significantly lower mass of pollutants at the outlet of the sludge treatment wetland planted with Phragmites, followed by those with Typha and then Scirpus. The distinct influence of plant species on pollution removal was explained by the sequestration of nitrogen and phosphorus in plant tissues and by the rhizosphere effect, which enhance the biodegradation of organic matter, allowed the nitrification process and created redox conditions favourable to the sorption of phosphorus. Filtration and evapotranspiration rates played a major role in limiting the discharge of pollutants, and the impact was enhanced by the fact that the sludge treatment wetland was not completely drained. PMID:22828383

Gagnon, Vincent; Chazarenc, Florent; Kõiv, Margit; Brisson, Jacques



Treatment of Wood Preserving Wastewater  

E-print Network

The wastewater produced by the wood preserving industry presents a difficult problem to treat economically. A review of the literature indicates the size of the industry has limited the pursuit of an orderly and economic solution. Atmospheric...

Reynolds, T. D.; Shack, P. A.


Control of C/N ratio for butyric acid production from textile wastewater sludge by anaerobic digestion.  


Increasing textile wastewaters and their biotreatment byproduct-waste activated sludge are serious pollution problems. Butyric acid production from textile wastewater sludge by anaerobic digestion at different C/N ratios was investigated. Adding starch to textile wastewater sludge with a C/N ratio of 30 increased the butyric acid concentration and percentage accounting for total volatile fatty acids (TVFAs) to 21.42 g/L and 81.5%, respectively, as compared with 21.42 g/L and 10.6% of textile wastewater sludge alone. The maximum butyric acid yield (0.45 g/g VS), conversion rate (0.74 g/g VS(digest)) and production rate (2.25 g/L d) was achieved at a C/N ratio of 30. The biological toxicity of textile wastewater sludge also significantly decreased after the anaerobic digestion. The study indicated that the anaerobic co-digestion of textile wastewater sludge and carbohydrate-rich waste with appropriate C/N ratio is possible for butyric acid production. PMID:22339023

Fu, Bo; Zhang, Jingjing; Fan, Jinfeng; Wang, Jin; Liu, He



Identification of the virucidal agent in wastewater sludge.  

PubMed Central

Anaerobically digested sludge contains an agent that causes irreversible inactivation of poliovirus. It has now been shown that the agent responsible for this activity is ammonia. The effect of ammonia on poliovirus appears to be typical for picornaviruses, but reovirus, an enteric virus of another group, is quite resistant to this compound. Because ammonia is not virucidal in its charged state, it expresses significant activity only at pH values greater than 8. Therefore, increasing the pH of sludge should cause rapid inactivation of indigenous picornaviruses. PMID:17367

Ward, R L; Ashley, C S



Properties of Biosolids from Sludge Treatment Wetlands for Land Application  

Microsoft Academic Search

\\u000a Sludge treatment wetlands consist of constructed wetlands which have been upgraded for sludge treatment over the last decades.\\u000a Sludge dewatering and stabilisation are the main features of this technology, leading to a final product which may be recycled\\u000a as an organic fertiliser or soil conditioner. In this study, biosolids from full-scale treatment wetlands were characterised\\u000a in order to evaluate the

Enrica Uggetti; Ivet Ferrer; Esther Llorens; David Güell; Joan García


Energy saving on wastewater treatment plants through improved online control: case study wastewater treatment plant Antwerp-South.  


This work provides a case study on how activated sludge modelling and computational fluid dynamics (CFD) can help to optimize the energy consumption of a treatment plant that is already equipped with an advanced control based on online nutrient measurements. Currently, aeration basins on wastewater treatment plant Antwerp-South are operated sequentially while flow direction and point of inflow and outflow vary as a function of time. Activated sludge modelling shows that switching from the existing alternating flow based control to a simultaneous parallel feeding of all aeration tanks saves 1.3% energy. CFD calculations also illustrate that the water velocity is still sufficient if some impellers in the aeration basins are shutdown. The simulations of the Activated Sludge Model No. 2d indicate that the coupling of the aeration control with the impeller control, and automatically switching off some impellers when the aeration is inactive, can save 2.2 to 3.3% of energy without affecting the nutrient removal efficiency. On the other hand, all impellers are needed when the aeration is active to distribute the oxygen. PMID:24622558

De Gussem, Kris; Fenu, Alessio; Wambecq, Tom; Weemaes, Marjoleine



Treatment of opium alkaloid containing wastewater in sequencing batch reactor (SBR)—Effect of gamma irradiation  

NASA Astrophysics Data System (ADS)

Aerobic biological treatment of opium alkaloid containing wastewater as well as the effect of gamma irradiation as pre-treatment was investigated. Biodegradability of raw wastewater was assessed in aerobic batch reactors and was found highly biodegradable (83-90% degradation). The effect of irradiation (40 and 140 kGy) on biodegradability was also evaluated in terms of BOD 5/COD values and results revealed that irradiation imparted no further enhancement in the biodegradability. Despite the highly biodegradable nature of wastewater, further experiments in sequencing batch reactors (SBR) revealed that the treatment operation was not possible due to sludge settleability problem observed beyond an influent COD value of 2000 mg dm -3. Possible reasons for this problem were investigated, and the high molecular weight, large size and aromatic structure of the organic pollutants present in wastewater was thought to contribute to poor settleability. Initial efforts to solve this problem by modifying the operational conditions, such as SRT reduction, failed. However, further operational modifications including addition of phosphate buffer cured the settleability problem and influent COD was increased up to 5000 mg dm -3. Significant COD removal efficiencies (>70%) were obtained in both SBRs fed with original and irradiated wastewaters (by 40 kGy). However, pre-irradiated wastewater provided complete thebain removal and a better settling sludge, which was thought due to degradation of complex structure by radiation application. Degradation of the structure was observed by GC/MS analyses and enhancement in filterability tests.

Bural, Cavit B.; Demirer, Goksel N.; Kantoglu, Omer; Dilek, Filiz B.



Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation  

E-print Network

; Methanobacteriales; naphthalene; PAH; sewage sludge; thermodynamic Introduction In Europe, treatment of wastewater for treatment in EU, followed by spreading on land, which accounted for 37% of the sewage sludge produced will diminish the use of artificial fertilizer. Sewage sludge is usually treated in wastewater treatment plants


Electrocoagulation treatment of oil-containing wastewaters  

SciTech Connect

A high degree of purification is achieved by the use of electrolysis for removing emulsified oils from wastewaters. Purification during electrolysis of oil-containing wastewaters occurs as the result of electroflotation, electrocoagulation, and electrophoresis. It is reported by Kharlamova and Tedoradze that most of the oil is removed by electrocoagulation. The authors have therefore studied the influence of various factors on electrocoagulation treatment and determined the kinetic parameters of anodic behavior of aluminum during removal and emulsified oils.

Pazenko, T.Ya.; Khalturina, T.I.; Kolova, A.F.; Rubailo, I.S.



Wastewater treatment plant instrumentation handbook. Final report  

SciTech Connect

Instruments are required for proper operation of wastewater plants. To be of use the instruments must be operable and maintainable. This requires care in the selection, application and installation of instruments and control equipment. Contents of the handbook address the how-to of designing and applying instrumentation and controls for waste treatment operations. Special focus is given to problems, causes and solutions. The handbook covers instruments, valves and pumps commonly used in wastewater plants.

Manross, R.C.



Effect of the application of various wastewater sludges on the properties of sandy soil.  


This research was conducted to determine the effect of various wastewater sludge (domestic type (B), mixture of industry and domestic type (L), aerobic food industry (P), anaerobic food industry (M)) levels on the properties of sandy soil, including pH, electrical conductivity (EC), and the levels of available N (NH4 and NO3) and P, diethylenetriamine pentaaceticacid (DTPA)-extractable microelements and heavy metals. An incubation experiment was performed in which sludges were applied at rates of 0, 40, 80, 120, and 160 tons ha(-1), and the effects on the soil properties were measured over a period of 150 days. Soil pH decreased and electrical conductivity increased with increasing levels of sludge application. The levels of NH4-N, NO3-N, available P, and DTPA-extractable heavy metals also increased with the application rate of the sludge. NO3-N content increased and NH4-N content decreased over time. The most unfavorable effects on soil properties were observed with the B sludge. Other soil characteristics changed according to the sludge properties. PMID:25632907

Asik, Bar?? Bülent; Aydinalp, Cumhur; Katkat, Ali Vahap; Sagban, Fatma Olcay Topaç



Applications of Energy Efficiency Technologies in Wastewater Treatment Facilities  

E-print Network

Application of Energy Efficiency Technologies in Wastewater Treatment Facilities Sandra Chow, Luke Werner, Yin Yin Wu and Ahmad R. Ganji BASE Energy, Inc. Depending on the level and type of treatment, municipal wastewater treatment (WWT) can...

Chow, S.; Werner, L.; Wu, Y. Y.; Ganji, A. R.


Effect of short-term exposure of selected aromatic nitrogen compounds on wastewater treatment.  


The biodegradation of melamine and p-nitrophenol (PNP) and their impact on wastewater treatment was evaluated after a short-term individual chemical loading in activated sludge treatment systems. Melamine was not degraded and quickly washed out of the system. PNP was degraded, but it led to a prolonged period of nitrification inhibition and deterioration of effluent quality. Both melamine and PNP loadings increased the effluent nitrogen concentrations, with their main contributors being melamine and NH4+, respectively. Nitrosomonas and Nitrospira were dominant in the activated sludge. Melamine did not affect the nitrifying assemblages, whereas PNP led to a reduced Nitrosomonas population size and complete washout of Nitrobacter. The results suggest that melamine is an inert compound if it enters the treatment facility for a short duration. Although the short-term exposure of melamine or PNP decreased effluent water quality,the impact of such aromatic nitrogen compounds on wastewater treatment performance may vary significantly. Water PMID:25509521

Guo, Jia; Sims, Atreyee; Gajaraj, Shashikanth; Wu, Donglei; Hu, Zhiqiang



Transformation of PVP coated silver nanoparticles in a simulated wastewater treatment process and the effect on microbial communities  

PubMed Central

Background Manufactured silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials in consumer goods and consequently their concentrations in wastewater and hence wastewater treatment plants are predicted to increase. We investigated the fate of AgNPs in sludge that was subjected to aerobic and anaerobic treatment and the impact of AgNPs on microbial processes and communities. The initial identification of AgNPs in sludge was carried out using transmission electron microscopy (TEM) with energy dispersive X-ray (EDX) analysis. The solid phase speciation of silver in sludge and wastewater influent was then examined using X-ray absorption spectroscopy (XAS). The effects of transformed AgNPs (mainly Ag-S phases) on nitrification, wastewater microbial populations and, for the first time, methanogenesis was investigated. Results Sequencing batch reactor experiments and anaerobic batch tests, both demonstrated that nitrification rate and methane production were not affected by the addition of AgNPs [at 2.5 mg Ag L-1 (4.9 g L-1 total suspended solids, TSS) and 183.6 mg Ag kg -1 (2.9 g kg-1 total solids, TS), respectively]. The low toxicity is most likely due to AgNP sulfidation. XAS analysis showed that sulfur bonded Ag was the dominant Ag species in both aerobic (activated sludge) and anaerobic sludge. In AgNP and AgNO3 spiked aerobic sludge, metallic Ag was detected (~15%). However, after anaerobic digestion, Ag(0) was not detected by XAS analysis. Dominant wastewater microbial populations were not affected by AgNPs as determined by DNA extraction and pyrotag sequencing. However, there was a shift in niche populations in both aerobic and anaerobic sludge, with a shift in AgNP treated sludge compared with controls. This is the first time that the impact of transformed AgNPs (mainly Ag-S phases) on anaerobic digestion has been reported. Conclusions Silver NPs were transformed to Ag-S phases during activated sludge treatment (prior to anaerobic digestion). Transformed AgNPs, at predicted future Ag wastewater concentrations, did not affect nitrification or methanogenesis. Consequently, AgNPs are very unlikely to affect the efficient functioning of wastewater treatment plants. However, AgNPs may negatively affect sub-dominant wastewater microbial communities. PMID:23497481



Overview of current biological and thermo-chemical treatment technologies for sustainable sludge management.  


Sludge is a semi-solid residue produced from wastewater treatment processes. It contains biodegradable and recalcitrant organic compounds, as well as pathogens, heavy metals, and other inorganic constituents. Sludge can also be considered a source of nutrients and energy, which could be recovered using economically viable approaches. In the present paper, several commonly used sludge treatment processes including land application, composting, landfilling, anaerobic digestion, and combustion are reviewed, along with their potentials for energy and product recovery. In addition, some innovative thermo-chemical techniques in pyrolysis, gasification, liquefaction, and wet oxidation are briefly introduced. Finally, a brief summary of selected published works on the life cycle assessment of a variety of sludge treatment and end-use scenarios is presented in order to better understand the overall energy balance and environmental burdens associated with each sludge treatment pathway. In all scenarios investigated, the reuse of bioenergy and by-products has been shown to be of crucial importance in enhancing the overall energy efficiency and reducing the carbon footprint. PMID:24980032

Zhang, Linghong; Xu, Chunbao Charles; Champagne, Pascale; Mabee, Warren



Emission of bisphenol analogues including bisphenol A and bisphenol F from wastewater treatment plants in Korea.  


Due to the regulation on bisphenol A (BPA) in several industrialized countries, the demand for other bisphenol analogues (BPs) as substitutes for BPA is growing. Eight BPs were determined in sludge from 40 representative wastewater treatment plants (WWTPs) in Korea. Total concentrations of BPs (?BP) in sludge ranged from sludge collected from WWTPs that received discharges from the paper and textile industries. The profiles of BPs were dependent on the proportions of industrial wastewater treated at each of the WWTPs. The sludge from industrial WWTPs contained elevated proportions of BPA, whereas sludge from domestic WWTPs was dominated by bisphenol F (BPF), suggesting use of BPF in certain industrial products in Korea. No significant correlations were found between BPs and the WWTP characteristics. The average per-capita emissions of BPs ranged from 0.04 (BPP) to 886 g capita(-1) d (BPA) through WWTP discharges. The emission fluxes of ?BP through industrial WWTPs were 2-3 orders of magnitudes higher than those calculated for domestic WWTPs, indicating that industrial discharges are the major source of BPs into the Korean environment. This is the first nationwide survey of BPs in sludge from Korean WWTPs. PMID:25303660

Lee, Sunggyu; Liao, Chunyang; Song, Geum-Ju; Ra, Kongtae; Kannan, Kurunthachalam; Moon, Hyo-Bang



Emergency Planning for Municipal Wastewater Treatment Facilities.  

ERIC Educational Resources Information Center

This manual for the development of emergency operating plans for municipal wastewater treatment systems was compiled using information provided by over two hundred municipal treatment systems. It covers emergencies caused by natural disasters, civil disorders and strikes, faulty maintenance, negligent operation, and accidents. The effects of such…

Lemon, R. A.; And Others


Identification of detergents as components of wastewater sludge that modify the thermal stability of reovirus and enteroviruses.  

PubMed Central

The agent in wastewater sludge previously shown to reduce the heat required to inactivate reovirus (R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol. 34:681--688, 1977) was "separated" from other sludge components and analyzed by infrared spectroscopy. The infrared spectrum of this material was quite similar to the spectra of commercial anionic detergents, and subsequent analyses of the fractionated sludge samples revealed that anionic detergents in sludge were copurified with the virucidal activity. Further measurements on the virucidal activities of specific detergents revealed that ionic detergents reduce the heat required to inactivate reovirus, that cationic detergents are more active than anionic, and that nonionic detergents are inactive. Several detergents were also shown to protect poliovirus and other enteroviruses against inactivation by heat. These results indicate that ionic detergents are the major component in wastewater sludge that reduce the thermal stability of reovirus and, in addition, that detergents are able to protect enteroviruses against heat. PMID:216308

Ward, R L; Ashley, C S



Comparative study of the methods used for treatment and final disposal of sewage sludge in European countries.  


Municipal wastewater treatment results to the production of large quantities of sewage sludge, which requires proper and environmentally accepted management before final disposal. In European Union, sludge management remains an open and challenging issue for the Member States as the relative European legislation is fragmentary and quite old, while the published data concerning sludge treatment and disposal in different European countries are often incomplete and inhomogeneous. The main objective of the current study was to outline the current situation and discuss future perspectives for sludge treatment and disposal in EU countries. According to the results, specific sludge production is differentiated significantly between European countries, ranging from 0.1 kg per population equivalent (p.e.) and year (Malta) to 30.8 kg per p.e. and year (Austria). More stringent legislations comparing to European Directive 86/278/EC have been adopted for sludge disposal in soil by several European countries, setting lower limit values for heavy metals as well as limit values for pathogens and organic micropollutants. A great variety of sludge treatment technologies are used in EU countries, while differences are observed between Member States. Anaerobic and aerobic digestion seems to be the most popular stabilization methods, applying in 24 and 20 countries, respectively. Mechanical sludge dewatering is preferred comparing to the use of drying beds, while thermal drying is mainly applied in EU-15 countries (old Member States) and especially in Germany, Italy, France and UK. Regarding sludge final disposal, sludge reuse (including direct agricultural application and composting) seems to be the predominant choice for sludge management in EU-15 (53% of produced sludge), following by incineration (21% of produced sludge). On the other hand, the most common disposal method in EU-12 countries (new Member States that joined EU after 2004) is still landfilling. Due to the obligations set by Directive 91/271/EC, a temporary increase of sludge amounts that are disposed in landfills is expected during the following years in EU-12 countries. Beside the above, sludge reuse in land and sludge incineration seem to be the main practices further adopted in EU-27 (all Member States) up to 2020. The reinforcement of these disposal practices will probably result to adoption of advanced sludge treatment technologies in order to achieve higher pathogens removal, odors control and removal of toxic compounds and ensure human health and environmental protection. PMID:22336390

Kelessidis, Alexandros; Stasinakis, Athanasios S



Spatial changes in carbon and nitrogen stable isotope ratios of sludge and associated organisms in a biological sewage treatment system.  


Carbon and nitrogen stable isotope ratios (?(13)C and ?(15)N) have been utilized as powerful tools for tracing energy or material flows within food webs in a range of environmental studies. However, the techniques have rarely been applied to the study of biological wastewater treatment technologies. We report on the spatial changes in ?(13)C and ?(15)N in sludge and its associated biotic community in a wastewater treatment system. This system consisted of an upflow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) which is a novel type of trickling filter. The results showed clear spatial changes in the ?(13)C and ?(15)N of suspended solids (SS), retained sludge, and macrofauna (oligochaetes and fly larvae) in the system. The ?(13)C and ?(15)N was used as a natural tracer to determine the SS dynamic throughout the system. The results imply that SS in the DHS effluent was mainly eluted from the retained sludge in the lower section of the DHS reactor. The ?(15)N of the retained sludge in the DHS reactor increased drastically from the inlet towards to the outlet, from -0.7‰ to 10.3‰. This phenomenon may be attributed to nitrogen conversion processes (i.e. nitrification and denitrification). The ?(15)N of oligochaetes also increased from the inlet to the outlet, which corresponded well to that of the retained sludge. Thus, the ?(15)N of the oligochaetes might simply mirror the ?(15)N of the retained sludge. On the other hand, the ?(13)C and ?(15)N of sympatric fly larvae differed from those of the oligochaetes sampled, indicating dietary differences between the taxa. Therefore ?(13)C and ?(15)N reflected both treatment and dietary characteristics. We concluded that ?(13)C and ?(15)N values are potentially useful as alternative indicators for investigating microbial ecosystems and treatment characteristics of biological wastewater treatment systems. PMID:25462745

Onodera, Takashi; Kanaya, Gen; Syutsubo, Kazuaki; Miyaoka, Yuma; Hatamoto, Masashi; Yamaguchi, Takashi



Innovative anaerobic/upflow sludge blanket filtration bioreactor for phosphorus removal from wastewater.  


Phosphorus is the key element to remove from aquatic environments to limit the growth of aquatic plants and algae and, thus, to control eutrophication. Because the upflow sludge blanket filtratio' (USBF) process, without addition of metal salts, entails low efficiency for phosphorus removal, we added an anaerobic reactor to the USBF bioreactor in order to promote the simultaneous removal of phosphorus and nitrogen from wastewater. The results revealed that the anaerobic/USBF bioreactor had a phosphorus removal efficiency up to 86%, with a sludge retention time (SRT) of 10 days, a hydraulic retention time (HRT) of 24 hours and an optimum COD/N/P ratio of 100/5/1. This ratio also improved the compaction quality of the sludge blanket in the USBF clarifier. The average specific phosphate uptake rate in the aerobic zone and the average specific phosphate release rate in the anaerobic reactor were 0.014 mg PO4-P removed/(g VSS x min) and 0.0525 mg PO4-P released/(g VSS x min), respectively. Secondary phosphorus release in the USBF clarifier was heightened with increasing HRT. Hence, the optimum total HRT can be selected between 16 and 24 hours based on effluent quality. Effluent phosphorus of about 1 mg/L was provided for wastewater with the COD/N/P ratio of 100/5/1 at the sludge age of 10 days and total HRT of 16 hours. This study illustrated that the anaerobic/USBF bioreactor at the optimum operational conditions can be an effective process for phosphorus removal from municipal wastewater. PMID:21877530

Khorsandi, H; Movahedyan, H; Bina, B; Farrokhzadeh, H



Ozone/UV treatment to enhance biodegradation of surfactants in industrial wastewater. CRADA final report  

SciTech Connect

The new owners of a surfactant manufacturing plant wanted to triple production but were limited by the plant`s wastewater treatment capacity. Mass balance calculations indicated that little aerobic biodegradation was occurring in the plant`s wastewater treatment system. Literature reviews and laboratory tests confirmed that as much as 60% of the plant`s products might resist aerobic biodegradation. Overall chemical losses, both solid and aqueous, were estimated at 3.8% of theoretical. Organic loadings to the wastewater treatment system were 170 kg/d of which 50 kg/d reached the biological treatment system. Pollution prevention measures have allowed a > 20% increase in production levels with a > 30% decrease in effluent volume and no increase in discharge of chemical oxygen demand (COD). A new dissolved air flotation (DAF) system removes 70% of the organic loading. Sludge volumes are lower by an order of magnitude than with the clarifier/drum-filter process it replaced.

Cline, J.E. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Sullivan, P.F. [Specialty Industrial Products, Inc., Spartanburg, SC (United States); Lovejoy, M.A.; Collier, J. [Sun River Innovations, Ltd., Lexington, KY (United States); Adams, C.D. [Univ. of Missouri, Rolla, MO (United States)



Anaerobic treatment of urban wastewater in membrane bioreactors: evaluation of seasonal temperature variations.  


The objective of this study was to evaluate the effect of seasonal temperature variations on the anaerobic treatment of urban wastewater in membrane bioreactors (MBRs). To this aim, sludge production, energy recovery potential, chemical oxygen demand (COD) removal and membrane permeability were evaluated in a submerged anaerobic MBR fitted with industrial-scale membrane units. The plant was operated for 172 days, between summer and winter seasons. Sludge production increased and energy recovery potential decreased when temperature decreased. COD removal and membrane permeability remained nearby stable throughout the whole experimental period. PMID:24718354

Giménez, J B; Martí, N; Robles, A; Ferrer, J; Seco, A



Characterization of brewery wastewater with spectrofluorometry analysis  

Microsoft Academic Search

The wastewater treatment systems from the three local breweries consist of upflow anaerobic sludge blanket (UASB) and activated sludge (AS) connected in series for which the influent and effluent from each treatment step were collected and determined for their dissolved organic matter (DOM) surrogate parameters including dissolved organic carbon (DOC), UV254 and SUVA254. The analyses suggested that the influent wastewater

Tansiphorn Janhom; Suraphong Wattanachira; Prasert Pavasant



Interpretation of the characteristics of ocean-dumped sewage sludge related to remote sensing  

NASA Technical Reports Server (NTRS)

Wastewater sludge characteristics in general, and characteristics of wastewater sludges generated by the City of Philadelphia in particular, were addressed. The types and sources of wastewater sludges, a description of sludge treatment and disposal processes, examination of sludge generation and management for the City of Philadelphia, and definition of characteristics for typical east coast sludges undergoing ocean disposal were discussed. Specific differences exist between the characteristics of primary and secondary wastewater sludges, especially with the nature and size distribution of the solids particles. The sludges from the City of Philadelphia monitored during remote sensing experiments were mixtures of various sludge types and lacked distinguishing characteristics. In particular, the anaerobic digestion process exerted the most significant influence on sludge characteristics for the City of Philadelphia. The sludges generated by the City of Philadelphia were found to be typical and harbor no unique features.

Pagoria, P. S.; Kuo, C. Y.



Activated sludge biotreatment of sulphurous waste emissions  

Microsoft Academic Search

Odours from wastewater treatment plants are comprised of a mixture of various gases, of which hydrogen sulphide (H2S) is the main constituent. Sulphurous compounds can be degraded by microorganisms commonly found in wastewater. The use of activated sludge (AS) diffusion as a dual-role system, for the treatment of wastewater and for odour control, offers an alternative to traditional sulphurous waste

Vera L. Barbosa; Joanna E. Burgess; Kathryn Darke; Richard M. Stuetz



Wastewater treatment benchmark: what can be achieved with simple control?  


In this paper a simple control strategy is applied to and assessed on the wastewater treatment benchmark. The controllers used in the presented control strategy are PI controllers, feedforward control and a step-feed procedure. The controlled variables are not directly the effluent concentrations but other process variables which have an effect on the effluent. The setting of set-points is also analyzed to select the values with the best performance. Set-point analysis has shown that with an optimal setting of set-points under stormy influent conditions, the achieved plant performance is also retained for rainy and dry influent conditions. The evaluation of plant performance indicates that with the proposed control strategy, a lower number of effluent violations has been achieved, as well as lower energy consumption and lower sludge production, when compared to results published up to now. Only the effluent quality criterion deteriorated. PMID:11936625

Vrecko, D; Hvala, N; Kocijan, J




SciTech Connect

The CH2M HILL Plateau Remediation Company (CHPRC) has recommended to the U.S. Department of Energy (DOE) a two phase approach for removal and storage (Phase 1) and treatment and packaging for offsite shipment (Phase 2) of the sludge currently stored within the 105-K West Basin. This two phased strategy enables early removal of sludge from the 105-K West Basin by 2015, allowing remediation of historical unplanned releases of waste and closure of the 100-K Area. In Phase 1, the sludge currently stored in the Engineered Containers and Settler Tanks within the 105-K West Basin will be transferred into sludge transport and storage containers (STSCs). The STSCs will be transported to an interim storage facility. In Phase 2, sludge will be processed (treated) to meet shipping and disposal requirements and the sludge will be packaged for final disposal at a geologic repository. The purpose of this study is to evaluate two alternatives for interim Phase 1 storage of K Basin sludge. The cost, schedule, and risks for sludge storage at a newly-constructed Alternate Storage Facility (ASF) are compared to those at T Plant, which has been used previously for sludge storage. Based on the results of the assessment, T Plant is recommended for Phase 1 interim storage of sludge. Key elements that support this recommendation are the following: (1) T Plant has a proven process for storing sludge; (2) T Plant storage can be implemented at a lower incremental cost than the ASF; and (3) T Plant storage has a more favorable schedule profile, which provides more float, than the ASF. Underpinning the recommendation of T Plant for sludge storage is the assumption that T Plant has a durable, extended mission independent of the K Basin sludge interim storage mission. If this assumption cannot be validated and the operating costs of T Plant are borne by the Sludge Treatment Project, the conclusions and recommendations of this study would change. The following decision-making strategy, which is dependent on the confidence that DOE has in the long term mission for T Plant, is proposed: (1) If the confidence level in a durable, extended T Plant mission independent of sludge storage is high, then the Sludge Treatment Project (STP) would continue to implement the path forward previously described in the Alternatives Report (HNF-39744). Risks to the sludge project can be minimized through the establishment of an Interface Control Document (ICD) defining agreed upon responsibilities for both the STP and T Plant Operations regarding the transfer and storage of sludge and ensuring that the T Plant upgrade and operational schedule is well integrated with the sludge storage activities. (2) If the confidence level in a durable, extended T Plant mission independent of sludge storage is uncertain, then the ASF conceptual design should be pursued on a parallel path with preparation of T Plant for sludge storage until those uncertainties are resolved. (3) Finally, if the confidence level in a durable, extended T Plant mission independent of sludge storage is low, then the ASF design should be selected to provide independence from the T Plant mission risk.




Wastewater treatment and energy : an analysis on the feasibility of using renewable energy to power wastewater treatment plants in Singapore  

E-print Network

Wastewater treatment is a very energy intensive industry. Singapore has a state-of-the-art wastewater treatment system that uses a number of sustainable techniques that greatly improve its overall efficiency. The centralized ...

Foley, Kevin John



Isolation of Nitrospira belonging to Sublineage II from a Wastewater Treatment Plant  

PubMed Central

Nitrite oxidation is a key step in nitrogen removal in biological wastewater treatment plants. Recently, two phylogenetically different Nitrospira (sublineages I and II) have been recognized as the numerically dominant nitrite-oxidizing bacteria in wastewater treatment plants. However, Nitrospira sublineage II inhabiting activated sludge was not isolated and its detailed properties were unclear. In this study, we developed a new method for the isolation of Nitrospira forming micro-colonies using a cell sorter. We obtained a novel pure strain “Nitrospira japonica” from the activated sludge. Subsequently, phylogenetic and physiological analyses revealed that Nitrospira japonica belongs to sublineage II and grew in medium containing formate. This method has the potential to isolate other uncultured microorganisms forming micro-colonies. PMID:24005844

Ushiki, Norisuke; Fujitani, Hirotsugu; Aoi, Yoshiteru; Tsuneda, Satoshi



Wetlands for wastewater treatment: Opportunities and limitations  

Microsoft Academic Search

This paper gives some introductory information on the use of wetlands for wastewater treatment. It focuses mainly on the functioning of constructed wetlands, in particular surface-flow and infiltration wetlands. The various processes which lead to water purification are briefly explained, in relation to the factors which influence their efficiency. The possibilities for optimization of the design and management of such

Jos T. A. Verhoeven; Arthur F. M. Meuleman



Calicivirus Removal in a Membrane Bioreactor Wastewater Treatment Plant?  

PubMed Central

To evaluate membrane bioreactor wastewater treatment virus removal, a study was conducted in southwest France. Samples collected from plant influent, an aeration basin, membrane effluent, solid sludge, and effluent biweekly from October 2009 to June 2010 were analyzed for calicivirus (norovirus and sapovirus) by real-time reverse transcription-PCR (RT-PCR) using extraction controls to perform quantification. Adenovirus and Escherichia coli also were analyzed to compare removal efficiencies. In the influent, sapovirus was always present, while the norovirus concentration varied temporally, with the highest concentration being detected from February to May. All three human norovirus genogroups (GI, GII, and GIV) were detected in effluent, but GIV was never detected in effluent; GI and GII were detected in 50% of the samples but at low concentrations. In the effluent, sapovirus was identified only once. An adenovirus titer showing temporal variation in influent samples was identified only twice in effluent. E. coli was always below the limit of detection in the effluent. Overall, the removal of calicivirus varied from 3.3 to greater than 6.8 log units, with no difference between the two main genogroups. Our results also demonstrated that the viruses are blocked by the membrane in the treatment plant and are removed from the plant as solid sludge. PMID:21666029

Sima, Laura C.; Schaeffer, Julien; Le Saux, Jean-Claude; Parnaudeau, Sylvain; Elimelech, Menachem; Le Guyader, Françoise S.



Optimization of the aerobic biological treatment of thermophilically treated refractory wastewater.  


A pilot scale conventional activated sludge was operated for over 600 days to study its effectiveness at further remediating the effluent of an existing industrial site's thermophilic biological treatment stage. During the course of the study, the activated sludge was able to further biodegrade the contaminants in the incoming industrial wastewater in terms of both BOD and nitrogen reductions at varying hydraulic and solids retention times, despite elevated concentrations of soluble copper being present. A limiting hydraulic retention time (HRT) for BOD removal of 1.5 days was observed as well as the loss of nitrification occurred at a solids retention time (SRT) of approximately 6 days. Biokinetic coefficients were determined with the maximum rate of substrate utilization per unit mass of microorganisms, k, of 0.14 mgVSS/(mgsBOD-d) and the Monod half velocity constant, K(s), of 9.4 mgsBOD/L. Simultaneous nitrification and denitrification (SND) of the nitrogenous compounds found in this wastewater was observed throughout the majority of the experimentation while the bulk DO in the system was greater than 1 mg/L. The activated sludge was estimated to contain soluble copper on the order of 1 mg/L throughout the course of operation with no apparent detriment to nitrification. Additionally, the activated sludge was able to biologically remove the main solvents found in the influent wastewater. The removals of trace levels of N-nitrosodimethylamine (NDMA) were also observed. PMID:16005148

Quesnel, David; Nakhla, George



Occurrence and fate of perfluorinated acids in two wastewater treatment plants in Shanghai, China.  


Perfluorinated acids (PFAs) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The discharge of wastewater effluent from municipal wastewater treatment plants (WWTPs) is a significant source of PFAs to the environment. In this study, wastewater and sludge samples were collected from two WWTPs in Shanghai, China, to investigate the contamination level and fate of PFAs in different stages of processing. The total concentrations of PFAs (?PFAs) in influent from plants A and B were 2,452 and 292 ng L(-1), respectively. Perfluoropentanoic acid (1,520?±?80 ng L(-1) in plant A and 89.2?±?12.1 ng L(-1) in plant B) was the predominant PFA in influent waters, followed by perfluorooctanoic acid. The concentration of ?PFAs ranged from 75.0 to 126.0 ng g(-1) dry weight in sludge samples from plant B, with perfluorooctanesulfonic acid as the predominant contaminant. The concentrations and fate of PFAs in different WWTPs vary. The ?PFAs entering plant A decreased significantly in the final effluent of activated sludge process, while that in plant B increased significantly in the final effluent of sequencing batch reactor system. The concentration changes could be due to the sorption onto sludge, or the degradation of PFAs precursors. PMID:23933955

Zhang, Chaojie; Yan, Hong; Li, Fei; Zhou, Qi



Nitrosamines in pilot-scale and full-scale wastewater treatment plants with ozonation.  


Ozone-based treatment trains offer a sustainable option for potable reuse applications, but nitrosamine formation during ozonation poses a challenge for municipalities seeking to avoid reverse osmosis and high-dose ultraviolet (UV) irradiation. Six nitrosamines were monitored in full-scale and pilot-scale wastewater treatment trains. The primary focus was on eight treatment trains employing ozonation of secondary or tertiary wastewater effluents, but two treatment trains with chlorination or UV disinfection of tertiary wastewater effluent and another with full advanced treatment (i.e., reverse osmosis and advanced oxidation) were also included for comparison. N-nitrosodimethylamine (NDMA) and N-nitrosomorpholine (NMOR) were the most prevalent nitrosamines in untreated (up to 89 ng/L and 67 ng/L, respectively) and treated wastewater. N-nitrosomethylethylamine (NMEA) and N-nitrosodiethylamine (NDEA) were detected at one facility each, while N-nitrosodipropylamine (NDPrA) and N-nitrosodibutylamine (NDBA) were less than their method reporting limits (MRLs) in all samples. Ozone-induced NDMA formation ranging from <10 to 143 ng/L was observed at all but one site, but the reasons for the variation in formation remain unclear. Activated sludge, biological activated carbon (BAC), and UV photolysis were effective for NDMA mitigation. NMOR was also removed with activated sludge but did not form during ozonation. PMID:25037928

Gerrity, Daniel; Pisarenko, Aleksey N; Marti, Erica; Trenholm, Rebecca A; Gerringer, Fred; Reungoat, Julien; Dickenson, Eric



Carbon and nutrient removal from on-site wastewater using extended-aeration activated sludge and ion exchange.  


The need to improve on-site wastewater treatment processes is being realized as populations move into more environmentally sensitive regions and regulators adopt the total maximum daily load approach to watershed management. Under many conditions, septic systems do not provide adequate treatment; therefore, advanced systems are required. These systems must remove significant amounts of biochemical oxygen demand (BOD) and suspended solids, and substantially nitrify, denitrify, and remove phosphorus. Many existing advanced on-site wastewater systems effectively remove BOD, suspended solids, and ammonia, but few substantially denitrify and uptake phosphorus. The purpose of this research was to design and test modifications to an existing on-site wastewater treatment system to improve denitrification and phosphorus removal. The Nayadic (Consolidated Treatment Systems, Inc., Franklin, Ohio), an established, commercially available, extended-aeration, activated sludge process, was used to represent a typical existing system. Several modifications were considered based on a literature review, and the option with the best potential was tested. To improve denitrification, a supplemental treatment tank was installed before the Nayadic and a combination flow splitter, sump, and pump box with a recirculation system was installed after it. A recirculation pump returned a high proportion of the system effluent back to the supplemental treatment tank. Two supplemental treatment tank sizes, three flowrates, and three recirculation rates were tested. Actual wastewater was dosed as brief slugs to the system in accordance with a set schedule. Several ion-exchange resins housed in a contact column were tested on the effluent for their potential to remove phosphorus. Low effluent levels of five-day biochemical oxygen demand, suspended solids, and total nitrogen were achieved and substantial phosphorous removal was also achieved using a 3780-L supplemental treatment tank, a recirculation ratio of 5:1, and a fine-grain activated aluminum-oxide-exchange media. Good results were also obtained with an 1890-L supplemental treatment tank and a recirculation ratio of 3:1. The most significant benefit of the supplemental treatment tank, in combination with the recirculation system, appears to be the low nitrogen concentration dosed to the Nayadic. By reducing the nitrogen concentration and spreading out its mass over time during no-flow periods, the Nayadic's inherent low-level denitrifying capacity was more closely matched and effective treatment was achieved. PMID:15523786

Safferman, Steven I; Burks, Bennette D; Parker, Robert A



Two years of the operation of a domestic MBR wastewater treatment plant  

NASA Astrophysics Data System (ADS)

The paper evaluates the results of data obtained from two years of observing an actual domestic wastewater treatment plant (WWTP) with an immersed membrane module. The domestic MBR (membrane bioreactor) WWTP was linked to a dwelling with four residents. Two different commercial flat sheet membrane modules were investigated. The membrane modules, as well as the whole WWTP, were tested with different fluxes as well as the response of the membrane and activated sludge to different conditions, such as actual peak wastewater flows, extremes temperatures (a winter below 5 °C), and high pH values.

Pikorová, Tina



Catalytic Wastewater Treatment Using Pillared Clays  

NASA Astrophysics Data System (ADS)

After introduction on the use of solid catalysts in wastewater treatment technologies, particularly advanced oxidation processes (AOPs), this review discussed the use of pillared clay (PILC) materials in three applications: (i) wet air catalytic oxidation (WACO), (ii) wet hydrogen peroxide catalytic oxidation (WHPCO) on Cu-PILC and Fe-PILC, and (iii) behavior of Ti-PILC and Fe-PILC in the photocatalytic or photo-Fenton conversion of pollutants. Literature data are critically analyzed to evidence the main direction to further investigate, in particularly with reference to the possible practical application of these technologies to treat industrial, municipal, or agro-food production wastewater.

Perathoner, Siglinda; Centi, Gabriele


Kinetics of biologically induced phosphorus precipitation in waste-water treatment  

Microsoft Academic Search

In waste-water treatment plants with enhanced biological phosphorus removal (EBPR), a part of the phosphorus can be eliminated by chemical precipitation. In experiments with inactivated sludge containing relatively high concentrations of dissolved calcium (?1.5molm?3) and phosphorus (?1molm?3), a pH-sensitive and partly reversible precipitation of calcium phosphates was observed at pH values below 8.0. A dynamic model was formulated on the

M. Maurer; D. Abramovich; H. Siegrist; W. Gujer



Temperature effect on UASB reactor operation for domestic wastewater treatment in temperate climate regions  

Microsoft Academic Search

The performance of an upflow anaerobic sludge blanket (UASB) reactor was investigated for the treatment of domestic wastewater at different operational temperatures (28, 20, 14 and 10°C) and loading rates. For each temperature studied a constant CODt removal was observed as long as the upflow velocity was lower than 0.35 m\\/h: 82% at 28°C, 68% at 14°C and 44% at

B. Lew; M. Belavski; S. Admon; S. Tarre; M. Green



Conditions and technologies of biological wastewater treatment in Hungary.  


A survey has been carried out involving 55 Hungarian wastewater treatment plants in order to evaluate the wastewater quality, the applied technologies and the resultant problems. Characteristically the treatment temperature is very wide-ranging from less than 10 °C to higher than 26 °C. Influent quality proved to be very variable regarding both the organic matter (typical COD concentration range 600-1,200 mg l(-1)) and the nitrogen content (typical NH(4)-N concentration range 40-80 mg l(-1)). As a consequence, significant differences have been found in the carbon availability for denitrification from site to site. Forty two percent of the influents proved to lack an appropriate carbon source. As a consequence of carbon deficiency as well as technologies designed and/or operated with non-efficient denitrification, rising sludge in the secondary clarifiers typically occurs especially in summer. In case studies, application of intermittent aeration, low DO reactors, biofilters and anammox processes have been evaluated, as different biological nitrogen removal technologies. With low carbon source availability, favoring denitrification over enhanced biological phosphorus removal has led to an improved nitrogen removal. PMID:22508132

Tardy, G M; Bakos, V; Jobbágy, A



The role of chemical oxidation in combined chemical-physical and biological processes: experiences of industrial wastewater treatment.  


In this work, some experiences are described concerning the application of chemical oxidation in the treatment of industrial wastewaters in combination with other chemical-physical and/or biological processes. In the first case, two different wastewaters from saturated and unsaturated polyester resin production were considered. In a second case, optimal process conditions were assessed for the treatment of a wastewater deriving from polystyrene production. A third experience dealt with a comparison among different processes (flocculation, Fenton process, ozonisation, oxidation by means of ozone and hydrogen peroxide, oxidation by means of hydrogen peroxide and UV radiation), for the pretreatment of two industrial wastewaters (the first one being produced in a textile factory, the second one coming from detergent manufacturing). The evaluation of different processes was carried out by means of laboratory scale tests, considering treatment efficiency (organic substance removal, changes in wastewater biodegradability) and parameters (chemicals and energy consumption, sludge production) which play an important role in cost determination. PMID:11695447

Bertanza, G; Collivignarelli, C; Pedrazzani, R



UASB treatment of wastewater containing concentrated benzoate  

SciTech Connect

The upflow anaerobic sludge blanket (UASB) process removed 97--99% of soluble chemical oxygen demand (COD) from wastewater containing concentrated benzoate at 37 C, pH 7.5, a hydraulic retention time of 9.8 h, and loading rates up to 30.6 g-COD/(L {center_dot} day) based on the reactor volume. About 95.2% of the total COD removed was converted to methane; 0.034 g of volatile suspended solids (VSS) was yielded for each gram of COD removed. The highly settleable granules were 1--3 mm in size with a layered microstructure and were composed in abundance of bacteria resembling the benzoate-degrading Syntrophus buswellii. Two interesting observations have led to the postulation that the degradation of benzoate into acetate was probably conducted completely inside the cell of Syntrophus buswellii-like bacteria: (1) no fatty acids except acetate were found in the effluent; and (2) the granules showed very limited butyrate-degrading capability and could not degrade propionate. This study demonstrated the feasibility of removing aromatic pollutants in wastewater by anaerobic processes.

Li, Y.Y.; Fang, H.H.P.; Chen, T.; Chui, H.K. [Univ. of Hong Kong (Hong Kong). Civil and Structural Engineering Dept.



Nitrogen removal by recycle water nitritation as an attractive alternative for retrofit technologies in municipal wastewater treatment plants  

Microsoft Academic Search

The recycle water from sludge processing in municipal wastewater treatment plants causes many serious problems in the efficiency and stability of the mainstream process. Thus, the design approach for recycle water is an important part of any biological nutrient removal system design when a retrofit technology is required for upgrading an existing plant. Moreover, the application of nitrogen removal from

K.-I. Gil; E. Choi



The cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater.  


The cold adaptability of microorganisms with different carbon source under 5°C was studied in activated sludge for treating synthetical wastewater. Phospholipid fatty acid (PLFA) analysis indicated contents of unsaturated fatty acids in cell membrane at 5°C were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25°C. PLFA biomarkers showed more Gram-negative bacteria enriched than Gram-positive bacteria in low-temperature activated sludge. The Shannon-Wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower PLFA diversity index (1.21-1.30) than that at 25°C and sodium acetate source was reverse (1.08-0.69). The 16S rRNA analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to Gram-negative bacteria. PMID:22940300

Niu, Chuan; Geng, Jinju; Ren, Hongqiang; Ding, Lili; Xu, Ke



Effects of wastewater sludge and its detergents on the stability of rotavirus.  

PubMed Central

Wastewater sludge reduced the heat required to inactivate rotavirus SA-11, and ionic detergents were identified as the sludge components responsible for this effect. A similar result was found previously with reovirus (R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol 36:889-897, 1978). The quantitative effects of individual ionic detergents on rotavirus and reovirus were very different, and rotavirus was found to be extremely sensitive to several of these detergents. However, neither virus was destabilized by nonionic detergents. On the contrary, rotavirus was stabilized by a nonionic detergent against the potent destabilizing effects of the ionic detergent sodium dodecyl sulfate. The destabilizing effects of both cationic and anionic detergents on rotavirus were greatly altered by changes in the pH of the medium. PMID:6250475

Ward, R L; Ashley, C S



An eco-friendly treatment of tannery wastewater using bioaugmentation with a novel microbial consortium.  


A novel microbial consortium (BM-S-1) enriched from natural soils was successfully used to treat tannery wastewater from leather manufacturing industries in Korea on a pilot scale. The objective of this study was to determine whether augmentation with a novel microbial consortium BM-S-1could successfully treat the recalcitrant wastewater without chemical pre-treatment in a tannery wastewater treatment system. Chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were monitored for water quality. The microbial population dynamics were analyzed using pyrosequencing, and denitrifying bacteria were quantified using real-time PCR (RT-PCR). The removal efficiencies for COD, TN and TP were greater than 91%, 79%, and 90%, respectively. The dominant phyla in the buffering tank (B), primary aeration (PA), secondary aeration (SA) and sludge digestion tank (SD) were Proteobacteria, Firmicutes, Bacteroidetes, Planctomycetes and Deinococcus-Thermus. Cluster analysis based on the UniFrac distance of the species in the different stages showed that the PA is similar to the SA, whereas the B is similar to the SD. qPCR of the nosZ genes showed the highest abundance of denitrifiers in B, which was increased 734-fold compared to the influent (I). It was hypothesized that anaerobic denitrifiers and the diverse microbial community may play important roles in the biological treatment of tannery wastewater. This technology may also contribute to the full-scale treatment of industrial wastewater containing food processing wastewater and marine sediment with high organic content. PMID:23947713

Kim, In-Soo; Ekpeghere, Kaluibe; Ha, Shin-Young; Kim, Soo-Hyeon; Kim, Bong-Soo; Song, Bongkeun; Chun, Jongsik; Chang, Jae-Soo; Kim, Hong-Gi; Koh, Sung-Cheol



Microbiological aspects of a bioreactor with submerged membranes for aerobic treatment of municipal wastewater.  


An aerobic membrane bioreactor treating municipal wastewater at complete biomass retention was studied in respect of microbiological parameters over a period of 380 days. The results were compared to those obtained from a conventional activated sludge wastewater treatment plant (WWTP) treating the same wastewater. Microscopically, significant changes in the structure of the flocs and of the ratio between free suspended and aggregated cells could be observed. The presence of filamentous bacteria varied from almost not present to very high numbers. With the exception of short periods after changes in operating conditions, protozoa and metazoa were rarely present in the sludge community. The rate of oxygen consumption and the cell detectability by fluorescence in situ hybridizatio (FISH) with rRNA-targeted oligonucleotide probes were used to assess the physiological state of the bacterial cells Oxygen consumption rates of sludge samples obtained from both the conventional and membrane filtration plant wer determined without and after addition of different energy and carbon sources. In contrast to the conventional activate sludge, a pronounced increase in respiration activity upon the addition of organic substrates could be observed in th membrane filtration sludge. In situ probing with the Bacteria-specific probe EUB338 visualized 40-50% of all DAPI stainable bacteria in the membrane bioreactor, compared to 80% cells detectable by FISH in the conventional activate sludge. These results suggest that bacteria present in the highly concentrated biomass of the membrane reactor use the energy supplied for their maintenance metabolism and were not in a physiological state characteristic for growth This assumption could explain the zero net biomass production observed in the reactor. PMID:11827345

Witzig, R; Manz, W; Rosenbergerb, S; Krügerb, U; Kraumeb, M; Szewzyk, U



Environmental profile of typical anaerobic/anoxic/oxic wastewater treatment systems meeting increasingly stringent treatment standards from a life cycle perspective.  


Stringent new legislation for wastewater treatment plants (WWTPs) is currently motivating innovation and optimization of wastewater treatment technologies. Evaluating the environmental performance of a wastewater treatment system is a necessary precursor before proposing implementation of WWTPs designed to address the global requirements for reduced resource use, energy consumption and environmental emissions. However, developing overly-sophisticated treatment methods may lead to negative environmental effects. This study was conducted to employ a process modeling approach from a life cycle perspective to construct and evaluate six anaerobic/anoxic/oxic wastewater treatment systems that include a water line, sludge line and bioenergy recovery system and was designed to meet different treatment standards in China. The results revealed that improved treatments optimized for local receiving watercourses can be realized at the cost of higher resource consumption and greenhouse gas emissions. Optimal Scenarios were also identified from different positive perspectives. PMID:23073087

Wang, Xu; Liu, Junxin; Ren, Nan-Qi; Duan, Zuoshan



Reference guide for industrial wastewater treatment. Final report  

SciTech Connect

This report provides a general reference guide for identifying, designing, and reviewing industrial water-pollution-abatement projects. The guidance will be useful to environmental engineers in the Department of Defense who are responsible for industrial-wastewater pollution abatement projects and to personnel responsible for operation and maintenance of domestic and/or industrial wastewater-treatment plants. Contents include: Industrial Wastewater Regulations; Handling and Disposal of Hazardous Wastes; Nature and Origin of Industrial Wastewater; The Industrial Waste Survey; Industrial Wastewater Control Technologies; Solution Development Methodology; Economics of Industrial Wastewater Treatment.

Not Available



Tracking human sewage microbiome in a municipal wastewater treatment plant.  


Human sewage pollution is a major threat to public health because sewage always comes with pathogens. Human sewage is usually received and treated by wastewater treatment plants (WWTPs) to control pathogenic risks and ameliorate environmental health. However, untreated sewage that flows into water environments may cause serious waterborne diseases, as reported in India and Bangladesh. To examine the fate of the human sewage microbiome in a local municipal WWTP of Hong Kong, we used massively parallel sequencing of 16S rRNA gene to systematically profile microbial communities in samples from three sections (i.e., influent, activated sludge, and effluent) obtained monthly throughout 1 year. The results indicated that: (1) influent sewage bacterial profile reflected the human microbiome; (2) human gut bacterial community was the dominant force shaping influent sewage bacterial profile; (3) most human sewage bacteria could be effectively removed by the WWTP; (4) a total of 75 genera were profiled as potentially pathogenic bacteria, most of which were still present in the effluent although at a very low level; (5) a grouped pattern of bacterial community was observed among the same section samples but a dispersed pattern was found among the different section samples; and (6) activated sludge was less affected by the influent sewage bacteria, but it showed a significant impact on the effluent bacteria. All of these findings provide novel insights toward a mechanistic understanding of the fate of human sewage microbiome in the WWTP. PMID:24305737

Cai, Lin; Ju, Feng; Zhang, Tong




EPA Science Inventory

A literature review of published and unpublished data was conducted to identify all conceivable alternative on-site systems, including wastewater manipulation, treatment and disposal options. Wastewater manipulation options included flow reduction, wasteload reduction and waste s...


Occurrence of Ammonia-Oxidizing Archaea in Wastewater Treatment Plant Bioreactors  

PubMed Central

We report molecular evidence that ammonia-oxidizing archaea (AOA) occur in activated sludge bioreactors used to remove ammonia from wastewater. Using PCR primers targeting archaeal ammonia monooxygenase subunit A (amoA) genes, we retrieved and compared 75 sequences from five wastewater treatment plants operating with low dissolved oxygen levels and long retention times. All of these sequences showed similarity to sequences previously found in soil and sediments, and they were distributed primarily in four major phylogenetic clusters. One of these clusters contained virtually identical amoA sequences obtained from all five activated sludge samples (from Oregon, Wisconsin, Pennsylvania, and New Jersey) and accounted for 67% of all the sequences, suggesting that this AOA phylotype may be widespread in nitrifying bioreactors. PMID:16885322

Park, Hee-Deung; Wells, George F.; Bae, Hyokwan; Criddle, Craig S.; Francis, Christopher A.



Estimation of methane emissions from a wastewater treatment plant in Valence  

NASA Astrophysics Data System (ADS)

Methane is the second most important anthropogenic greenhouse gas emitted; its 20 year global-warming potential is about 56 to 72 depending on authors. One of its sources is the treatment of wastewaters and more particularly anaerobic digestion processes and sludge treatment. To reduce methane emissions from wastewater treatment plants, it is necessary to precisely quantify the amount emitted globally by the plant but also for each step of the process. Fixing the potential leaks and collecting the methane emitted by the different processes allows to reduce methane emissions and costs as methane can be sold or used on-site as an energy source. Moreover improve methods to estimate flow from atmospheric measurements of methane will reduce uncertainties in the inversion models. Several measurement campaigns have been realized in the wastewater treatment plant of Valence, France. This plant treats up to 2800 m3/h of polluted water through a biological treatment. To quantify methane emissions from this wastewater treatment plant, a dual tracer method had been used. It consists in releasing acetylene collocated with the methane source and in measuring both concentrations in the emitted plumes. In parallel, an atmospheric local scale model was used to compare with the experimental results. The higher concentration of methane's emissions was observed around the wastewater arrival. Plant's emissions are in the same range as estimations from the CITEPA French inventory. Measurements during the campaign are well correlated with the model results.

Ars, Sébastien; Yver Kwok, Camille; Bousquet, Philippe; Broquet, Grégoire; Ciais, Philippe; Wu, Lin



Treatment of beet sugar wastewater by UAFB bioprocess.  


The aim of this work was to study the treatment of strong beet sugar wastewater by an upflow anaerobic fixed bed (UAFB) at pilot plant scale. Three fixed bed bioreactors (each 60 L) were filled with standard industrial packing, inoculated with anaerobic culture (chicken manure, cow manure, anaerobic sludge digested from domestic wastewater) and operated at 32-34 degrees C with 20 h hydraulic retention time (HRT) and influent COD ranging between 2000-8000 mg/L. Under these conditions the maximum efficiency of organic content reduction in the reactor ranged from 75% to 93%. The reactor filled with standard pall rings made of polypropylene with an effective surface area of 206 m(2)/m(3) performed best in comparison to the reactor filled with cut polyethylene pipe 134 m(2)/m(3) and reactor filled with PVC packing (50 m(2)/m(3)). There was 2-7% decrease in efficiency with PE while it was 10-16% in case of PVC when compared to standard pall rings. The study provided a very good basis for comparing the effect of packing in reduction efficiency of the system. PMID:17391955

Farhadian, Mehrdad; Borghei, Mehdi; Umrania, Valentina V



Feasibility of fly ash-based composite coagulant for coal washing wastewater treatment.  


In this study, several fly ash (FA)-based composite coagulants, leached by hydrochloric acid, were prepared to treat coal washing wastewater. The concentrations of Al(3+) and Fe(2+)/Fe(3+) in the leachates and coagulants were analyzed, and optimal experimental conditions, including coagulant dosage and initial pH, were determined using various analytical techniques (scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction (XRD), X-ray fluorescence (XRF), particle-size analysis, zeta potential, pH and conductivity measurements). A suspended solids (SS) and chemical oxygen demand (COD) removal efficiency from the effluent treated by one of the coagulants reached 99.61% and 96.48%, respectively, at dosages of 10 g l(-1) (initial pH of 9, adjusted by CaO). This indicates that the coagulant was an effective agent for coal washing wastewater treatment, and that the leached Al(3+) and Fe(3+) and introduced Ca(2+) may have improved the coagulation process. Analysis of the dry sludge composition and slurry particle size distribution of the coal washing wastewater showed that charged colloidal particles and the fine particle distribution in the coal washing wastewater make the wastewater treatment a difficult process. Results from this study could provide a novel approach for the treatment of coal washing wastewater and coal fly ash utilization. PMID:22197558

Yan, Long; Wang, Yufei; Ma, Hongzhu; Han, Zhiping; Zhang, Qiang; Chen, Yashao



Validation and implementation of model based control strategies at an industrial wastewater treatment plant.  


In this paper, the practical implementation and validation of advanced control strategies, designed using model based techniques, at an industrial wastewater treatment plant is demonstrated. The plant under study is treating the wastewater of a large pharmaceutical production facility. The process characteristics of the wastewater treatment were quantified by means of tracer tests, intensive measurement campaigns and the use of on-line sensors. In parallel, a dynamical model of the complete wastewater plant was developed according to the specific kinetic characteristics of the sludge and the highly varying composition of the industrial wastewater. Based on real-time data and dynamic models, control strategies for the equalisation system, the polymer dosing and phosphorus addition were established. The control strategies are being integrated in the existing SCADA system combining traditional PLC technology with robust PC based control calculations. The use of intelligent control in wastewater treatment offers a wide spectrum of possibilities to upgrade existing plants, to increase the capacity of the plant and to eliminate peaks. This can result in a more stable and secure overall performance and, finally, in cost savings. The use of on-line sensors has a potential not only for monitoring concentrations, but also for manipulating flows and concentrations. This way the performance of the plant can be secured. PMID:11547977

Demey, D; Vanderhaegen, B; Vanhooren, H; Liessens, J; Van Eyck, L; Hopkins, L; Vanrolleghem, P A



Temporal and spatial contamination of polybrominated diphenyl ethers (PBDEs) in wastewater treatment plants in Hong Kong.  


Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants which cause adverse effects to human health and environments. Wastewater treatment plants (WWTPs) receive PBDEs from various discharges but also release them back to the environment via treated effluent and sludge, depending on the removal efficiency of WWTPs. This study investigated the contamination of PBDEs in primary influent, final effluent and dewatered sludge in four WWTPs in Hong Kong from October 2011 to January 2013. Results showed that the concentrations and composition profiles of eight PBDE congeners (BDE-28, ?47, ?99, ?100, ?153, ?154,?183 and ?209) differed among WWTPs and fluctuated during the study period. Higher concentrations of PBDEs were detected in the influent and dewatered sludge from the two WWTPs receiving both domestic and industrial wastewaters than the two serve mainly residential and commercial districts. However, the PBDE concentrations in the effluent were comparable among WWTPs. The concentrations of ?8PBDEs (total of eight congeners) in the influent of all WWTPs ranged from 1 to 254 ng L(-1) but decreased to 12-27 ng L(-1) in effluent, with removal efficiency ranged from 20 to 53%. High concentrations of PBDEs, ranging from 9 to 307 ng g(-1) dry weights, were detected in dewatered sludge. The predominated congeners in influent were BDE-47 and -209 but shifted to BDE-47 and ?99 in effluent and BDE-209 in dewatered sludge. Every day, it is estimated 0.66-73 g PBDEs entered the four WWTPs, while 0.38-38 g and 0.17-17 g PBDEs were discharged to the surrounding waters via effluent and disposed to landfill sites in sludge form, respectively. These results indicated that the four WWTPs in Hong Kong were not designed for effectively removal of PBDEs, 52-80% of the incoming PBDEs were still remained in effluent and 21-45% was precipitated in sludge, both outputs became significant contamination sources. PMID:25247482

Deng, Dan; Chen, Hexiang; Tam, Nora F Y



Hybrid Treatment Systems for Dye Wastewater  

Microsoft Academic Search

Virtually all the known physicochemical and biological techniques have been explored for treatment of extremely recalcitrant dye wastewater; none, however, has emerged as a panacea. A single universally applicable end-of-pipe solution appears to be unrealistic, and combination of appropriate techniques is deemed imperative to devise technically and economically feasible options. An in-depth evaluation of wide range of potential hybrid technologies

Faisal Ibney Hai; Kazuo Yamamoto; Kensuke Fukushi



Nitrous oxide emissions from wastewater treatment processes  

PubMed Central

Nitrous oxide (N2O) emissions from wastewater treatment plants vary substantially between plants, ranging from negligible to substantial (a few per cent of the total nitrogen load), probably because of different designs and operational conditions. In general, plants that achieve high levels of nitrogen removal emit less N2O, indicating that no compromise is required between high water quality and lower N2O emissions. N2O emissions primarily occur in aerated zones/compartments/periods owing to active stripping, and ammonia-oxidizing bacteria, rather than heterotrophic denitrifiers, are the main contributors. However, the detailed mechanisms remain to be fully elucidated, despite strong evidence suggesting that both nitrifier denitrification and the chemical breakdown of intermediates of hydroxylamine oxidation are probably involved. With increased understanding of the fundamental reactions responsible for N2O production in wastewater treatment systems and the conditions that stimulate their occurrence, reduction of N2O emissions from wastewater treatment systems through improved plant design and operation will be achieved in the near future. PMID:22451112

Law, Yingyu; Ye, Liu; Pan, Yuting; Yuan, Zhiguo



Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater.  


The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200-7700gm(-3)d(-1) and 6.0-70.0gm(-3)d(-1), and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI-AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H2/CH4 production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion. PMID:25497029

Zhu, Liang; Jin, Jie; Lin, Haizhuan; Gao, Kaituo; Xu, Xiangyang



Electrochemical advanced oxidation and biological processes for wastewater treatment: a review of the combined approaches.  


As pollution becomes one of the biggest environmental challenges of the twenty-first century, pollution of water threatens the very existence of humanity, making immediate action a priority. The most persistent and hazardous pollutants come from industrial and agricultural activities; therefore, effective treatment of this wastewater prior to discharge into the natural environment is the solution. Advanced oxidation processes (AOPs) have caused increased interest due to their ability to degrade hazardous substances in contrast to other methods, which mainly only transfer pollution from wastewater to sludge, a membrane filter, or an adsorbent. Among a great variety of different AOPs, a group of electrochemical advanced oxidation processes (EAOPs), including electro-Fenton, is emerging as an environmental-friendly and effective treatment process for the destruction of persistent hazardous contaminants. The only concern that slows down a large-scale implementation is energy consumption and related investment and operational costs. A combination of EAOPs with biological treatment is an interesting solution. In such a synergetic way, removal efficiency is maximized, while minimizing operational costs. The goal of this review is to present cutting-edge research for treatment of three common and problematic pollutants and effluents: dyes and textile wastewater, olive processing wastewater, and pharmaceuticals and hospital wastewater. Each of these types is regarded in terms of recent scientific research on individual electrochemical, individual biological and a combined synergetic treatment. PMID:24965093

Ganzenko, Oleksandra; Huguenot, David; van Hullebusch, Eric D; Esposito, Giovanni; Oturan, Mehmet A



Online nonlinear sequential Bayesian estimation of a biological wastewater treatment process.  


Online estimation of unknown state variables is a key component in the accurate modelling of biological wastewater treatment processes due to a lack of reliable online measurement systems. The extended Kalman filter (EKF) algorithm has been widely applied for wastewater treatment processes. However, the series approximations in the EKF algorithm are not valid, because biological wastewater treatment processes are highly nonlinear with a time-varying characteristic. This work proposes an alternative online estimation approach using the sequential Monte Carlo (SMC) methods for recursive online state estimation of a biological sequencing batch reactor for wastewater treatment. SMC is an algorithm that makes it possible to recursively construct the posterior probability density of the state variables, with respect to all available measurements, through a random exploration of the states by entities called 'particle'. In this work, the simplified and modified Activated Sludge Model No. 3 with nonlinear biological kinetic models is used as a process model and formulated in a dynamic state-space model applied to the SMC method. The performance of the SMC method for online state estimation applied to a biological sequencing batch reactor with online and offline measured data is encouraging. The results indicate that the SMC method could emerge as a powerful tool for solving online state and parameter estimation problems without any model linearization or restrictive assumptions pertaining to the type of nonlinear models for biological wastewater treatment processes. PMID:21792564

Lee, Joong-Won; Hong, Yoon-Seok Timothy; Suh, Changwon; Shin, Hang-Sik



Economic evaluation of alternative wastewater treatment plant options for pulp and paper industry.  


Excessive water consumption in pulp and paper industry results in high amount of wastewater. Pollutant characteristics of the wastewater vary depending on the processes used in production and the quality of paper produced. However, in general, high organic material and suspended solid contents are considered as major pollutants of pulp and paper industry effluents. The major pollutant characteristics of pulp and paper industry effluents in Turkey were surveyed and means of major pollutant concentrations, which were grouped in three different pollution grades (low, moderate and high strength effluents), and flow rates within 3000 to 10,000m(3)/day range with 1000m(3)/day steps were used as design parameters. Ninety-six treatment plants were designed using twelve flow schemes which were combinations of physical treatment, chemical treatment, aerobic and anaerobic biological processes. Detailed comparative cost analysis which includes investment, operation, maintenance and rehabilitation costs was prepared to determine optimum treatment processes for each pollution grade. The most economic and technically optimal treatment processes were found as extended aeration activated sludge process for low strength effluents, extended aeration activated sludge process or UASB followed by an aeration basin for medium strength effluents, and UASB followed by an aeration basin or UASB followed by the conventional activated sludge process for high strength effluents. PMID:20870270

Buyukkamaci, Nurdan; Koken, Emre



Investigation and assessment of sludge pre-treatment processes.  


The pre-treatment of sludges by disintegration will result in a number of changes in sludge properties. Floc destruction as well as cell disintegration will occur. This leads to an increase of soluble substances and fine particles. Furthermore, biochemical reactions may appear during or immediately after disintegration. The influence of disintegration of excess sludge on anaerobic digestion was studied in full scale. A stirred ball mill, an ultrasound disintegrator, a lysate centrifuge and ozone treatment were used. The results of the degradation process were compared to a reference system without pre-treatment. An enhancement of the degree of degradation of 7.4% to 20% was observed. The pollution of sludge water as well as the dewatering properties of the digested sludge were investigated. COD and ammonia in the sludge water were increased and a higher polymer demand was observed while the solid content after dewatering stayed almost unchanged. Based on these results the cost effectiveness has been assessed taking into account different conditions (size of WWTP, cost for disposal, etc.). Capital and energy costs are the main factors while the decrease in disposal costs due to the reduced amount of sludge is the main profit factor. PMID:15259943

Müller, J A; Winter, A; Strünkmann, G



Treatment of acid mine wastewaters  

SciTech Connect

Acid mine drainage often results from the oxidation sulfide minerals to form sulfuric acid. As a consequence, high concentrations of metals in the both the suspended and dissolved state result from the low pH water. This paper discusses several of the more common treatment methods for acid mine drainage including the use of chemical precipitation agents, pH correction agents, filtration methods, and biodegradation methods. Advanced treatment technologies are also briefly described and include microfiltration, reverse osmosis, ion exchange, and electrodialysis.

Hayward, D.; Barnard, R.



Biosensor-based control of nitrification inhibitor in municipal wastewater treatment plants.  


The effect of potassium cyanide (KCN) on nitrification processes in municipal wastewater treatment plants was studied by batch nitrification tests, which indicated that nitrification processes tend to be inhibited at a lower KCN concentration than the present discharge standard to sewerage. The experiment of the biosensor using nitrifying bacteria was also conducted for continuous monitoring of nitrification inhibitor in influent wastewater, and demonstrated that the biosensor can detect KCN at as low as EC10 of the abovementioned batch nitrification test. Moreover, to determine the effectiveness of application of the biosensor to avoid the impact of KCN due to an accidental spillage in a sewerage system, KCN was intentionally injected into the experimental models of activated sludge process equipped both with and without the biosensor. The model with the biosensor that could detect KCN could divert the wastewater including KCN to a refuge tank, which resulted in the avoidance of upset of the activated sludge process. On the other hand, the model without the biosensor was upset in the nitrification process due to KCN. Such differences demonstrate the effectiveness of the biosensor applied to countermeasures of an accidental spillage of toxic chemicals to avoid upset of nitrification in municipal wastewater treatment plants. PMID:16722087

Okayasu, Y; Tanaka, H; Inui, T; Tanaka, Y



Phosphorus recovery by struvite crystallization in WWTPs: influence of the sludge treatment line operation.  


Phosphorus recovery by struvite (MgNH(4)PO(4).6H(2)O) crystallization is one of the most widely recommended technologies for treating sludge digester liquors especially in wastewater treatments plants (WWTP) with enhanced biological phosphorus removal (EBPR). In this paper, phosphorus recovery by struvite crystallization is assessed using the rejected liquors resulting from four different operational strategies of the sludge treatment line. Phosphorus precipitation and recovery efficiencies of between 80-90% and 70-85%, respectively, were achieved in the four experiments. The precipitates formed were mainly struvite, followed by amorphous calcium phosphate and, in some experiments, by calcite. The highest global phosphorus recovery taking into account both the sludge line and the crystallizer was achieved when mixed thickening and high elutriation were carried out (8.4 gP/kg treated sludge). However, low struvite content was obtained in the crystallizer with this operation scheme due to the high calcium content in the elutriation stream. Therefore, if the final purpose is to obtain struvite, the reduction of the elutriation flowrate is widely recommended in the case of high water hardness. PMID:20089291

Martí, N; Pastor, L; Bouzas, A; Ferrer, J; Seco, A



Investigation of EPS Characteristics and their Effects on Waste Activated Sludge Digestion  

E-print Network

activated sludge (WAS) from wastewater treatment plants (WWTP) demands extensive sludge dewatering, and dewatering performance were made over time. · Certain extraction techniques have been shown to release EPS

Mountziaris, T. J.


40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?  

Code of Federal Regulations, 2011 CFR

... This subpart exempts combustion units that incinerate sewage sludge and are not located at a wastewater treatment facility designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g.,...



40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?  

... This subpart exempts combustion units that incinerate sewage sludge and are not located at a wastewater treatment facility designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g.,...



40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?  

Code of Federal Regulations, 2012 CFR

... This subpart exempts combustion units that incinerate sewage sludge and are not located at a wastewater treatment facility designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g.,...



40 CFR 60.4780 - What sewage sludge incineration units are exempt from this subpart?  

Code of Federal Regulations, 2013 CFR

... This subpart exempts combustion units that incinerate sewage sludge and are not located at a wastewater treatment facility designed to treat domestic sewage sludge. These units may be subject to another subpart of this part (e.g.,...



Wastewater treatment in coal conversion  

Microsoft Academic Search

Water Purification Associates has contracted with the US Environmental Protection Agency to prepare a manual describing water treatment control technology specific to fuel conversion plant sites in the western United States. The information contained in this report may become part of an EPA Standards of Practice Manual. Most plants converting coal to other fuels use a large quantity of clean

R. E. Hicks; D. J. Goldstein; F. B. Seufert; I. W. Wei



On the understanding and control of the spontaneous heating of dried tannery wastewater sludge.  


We studied the spontaneous heating of dried sludge produced by treating wastewater mainly originating from tanneries. Heating up to burning has been observed in the presence of air and moisture, starting at ambient temperature. To understand and prevent the process we combined chemical and morphological analyses (ESEM) with thermal activity monitoring in insulated vessels. Selective additions of chemicals, either to amplify or depress the reactivity, have been used to investigate and identify both the chemical mechanism causing the sludge self-heating, and a prevention or a mitigation strategy. FeS additions accelerate the onset of reactivity, while S sustains it over time. On the contrary, Ca(OH)2, Na2CO3, NaHCO3, FeCl2, EDTA, NaClO can limit, up to completely preventing, the exothermic activity. All the experimental evidences show that the reactions supporting the dried sludge self-heating involve the Fe/S/O system. The total suppression of the reactivity requires amounts of additives that are industrially incompatible with waste reduction and economics. The best prevention requires reduction or removal of S and Fe from the dried solid matrix. PMID:24484766

Biasin, A; Della Zassa, M; Zerlottin, M; Refosco, D; Bertani, R; Canu, P



Recycling potential of air pollution control residue from sewage sludge thermal treatment as artificial lightweight aggregates.  


Thermal treatment of sewage sludge produces fly ash, also known as the air pollution control residue (APCR), which may be recycled as a component of artificial lightweight aggregates (ALWA). Properties of APCR are typical: high content of Ca, Mg, P2O5, as well as potential to induce alkaline reactions. These properties indicate that ALWA prepared with a high content of APCR may remove heavy metals, phosphorus, and ammonium nitrogen from wastewater with high efficiency. The aim of this preliminary study was to determine the optimal composition of ALWA for potential use as a filter media in wastewater treatment systems. Five kinds of ALWA were produced, with different proportions of ash (shown as percentages in subscripts) in mixture with bentonite: ALWA0 (reference), ALWA12.5, ALWA25, ALWA50, and ALWA100. The following parameters of ALWA were determined: density, bulk density, compressive strength, hydraulic conductivity, and removal efficiency of ions Zn(2+), NH4 (+), and PO4 (3-). Tests showed that ALWA had good mechanical and hydraulic properties, and might be used in wastewater filtering systems. Phosphates and zinc ions were removed with high efficiency (80-96%) by ALWA25-100 in static (batch) conditions. The efficiency of ammonium nitrogen removal was low, <18%. Artificial wastewater treatment performance in dynamic conditions (through-flow), showed increasing removal efficiency of Zn(2+), PO4 (3-) with a decrease in flow rate. PMID:24616344

Bialowiec, Andrzej; Janczukowicz, Wojciech; Gusiatin, Zygmunt M; Thornton, Arthur; Rodziewicz, Joanna; Zielinska, Magdalena



Hydrogen sulfide removal from coal gas by the metal-ferrite sorbents made from the heavy metal wastewater sludge.  


The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 degrees C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction. PMID:18440697

Tseng, Ting Ke; Chang, Han Ching; Chu, Hsin; Chen, Hung Ta



Investigation into the distribution of polycyclic aromatic hydrocarbons (PAHs) in wastewater sewage sludge and its resulting pyrolysis bio-oils.  


This study firstly investigated the distributions of 16 US EPA priority controlled polycyclic aromatic hydrocarbons (PAHs) in seven kinds of different wastewater sewage sludges and bio-oils from the sludge pyrolysis. A lab-scale tube furnace was used to simulate sludge pyrolysis and retrieve condensed oils. PAH determination was conducted with the extraction, concentration, and purification of PAHs in sludge samples and the resulting bio-oils, and then GC-MS analysis. Then, the factors influencing the distributions of different rings of PAHs in pyrolysis bio-oil, such as the chemical characteristics of raw sewage sludge and pyrolysis condition, were analyzed. It was noted that the total amount of PAHs in raw sludge is evidently varied with the sludge resource, with values ranging between 9.19 and 23.68 mg/kg. The middle molar weight (MMW) PAH distribution is dominant. PAH concentrations in sludge pyrolysis bio-oil were ranged from 13.72 to 48.9 mg/kg. The most abundant PAHs were the low molar weight (LMW) PAHs. It could be found that the concentration of LMW PAHs in bio-oil is correlated with MMW PAHs in raw sewage sludge at best, which the correlation coefficient is 0.607. For MMW and HMW (high molar weight) PAHs, they are significantly correlated with HMW PAHs in raw sewage sludge, which the correlation coefficients are 0.672 and 0.580, respectively. The concentration of LMW PAHs in bio-oil is also relatively significant and correlated with the volatile matter content of raw sludge. In addition, it was proved that final temperature and residence time have important influences on PAH generations during the pyrolysis of sewage sludge. PMID:24388824

Hu, Yanjun; Li, Guojian; Yan, Mi; Ping, Chuanjuan; Ren, Jianli



Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions  

SciTech Connect

The Sludge Treatment Project (STP), managed for the U. S. DOE by Fluor Hanford (FH), was created to design and operate a process to eliminate uranium metal from K Basin sludge prior to packaging for Waste Isolation Pilot Plant (WIPP). The STP process uses high temperature liquid water to accelerate the reaction, produce uranium dioxide from the uranium metal, and safely discharge the hydrogen. Under nominal process conditions, the sludge will be heated in pressurized water at 185°C for as long as 72 hours to assure the complete reaction (corrosion) of up to 0.25-inch diameter uranium metal pieces. Under contract to FH, the Pacific Northwest National Laboratory (PNNL) conducted bench-scale testing of the STP hydrothermal process in November and December 2006. Five tests (~50 ml each) were conducted in sealed, un-agitated reaction vessels under the hydrothermal conditions (e.g., 7 to 72 h at 185°C) of the STP corrosion process using radioactive sludge samples collected from the K East Basin and particles/coupons of N Reactor fuel also taken from the K Basins. The tests were designed to evaluate and understand the chemical changes that may be occurring and the effects that any changes would have on sludge rheological properties. The tests were not designed to evaluate engineering aspects of the process. The hydrothermal treatment affected the chemical and physical properties of the sludge. In each test, significant uranium compound phase changes were identified, resulting from dehydration and chemical reduction reactions. Physical properties of the sludge were significantly altered from their initial, as-settled sludge values, including, shear strength, settled density, weight percent water, and gas retention.

Delegard, Calvin H.; Schmidt, Andrew J.; Thornton, Brenda M.




EPA Science Inventory

The Site 4 plant treats 11 to 12 MGD of wastewater from domestic (80% of influent) and industrial (20% of influent) sources. he treated primary/secondary sludge is dewatered using cloth filter presses to approximately 35 percent solids. he dried filter cakes are incinerated in a ...



EPA Science Inventory

The Site 4 plant treats 11 to 12 MGD of wastewater from domestic (80% of influent) and industrial (20% of influent) sources. he treated primary/secondary sludge is dewatered using cloth filter presses to approximately 35 percent solids. he dried filter cakes are incinerated in a ...



EPA Science Inventory

The Site 1 plant treats 36MGD of wastewater and the blended primary/secondary sludge is dewatered to approximately 16 to 2O percent solids. ludge is incinerated by a six-hearth unit at approximately 6.0 wet tons per hour. missions are controlled by a three tray impingement scrubb...


Towards a complete recycling of phosphorus in wastewater treatment--options in Germany.  


Global reserves of mineral phosphorus are finite and the recycling of phosphorus from wastewater, a significant sink for phosphorus, can contribute to a more sustainable use. In Germany, Switzerland, and the Netherlands, an increasing percentage of municipal sewage sludge is incinerated and the contained phosphorus is lost. This paper reviews current technologies and shows that a complete phosphorus recovery from wastewater is technically feasible. Depending on the composition of the sewage sludge ash (SSA), there are various options for phosphorus recovery that are presented. Iron-poor SSAs can be used directly as substitute for phosphate rock in the electrothermal phosphorus process. SSAs with low heavy metal contents can be used as fertilizer without prior metal elimination. Ashes not suitable for direct recycling can be processed by thermal processes. Operators of wastewater treatment plants can additionally influence the ash composition via the selection of precipitants and the control of (indirect) dischargers. This way, they can choose the most suitable phosphorus recovery option. For sewage sludge that is co-incinerated in power plants, municipal waste incinerators or cement kilns phosphorus recovery is not possible. The phosphorus is lost forever. PMID:22053454

Petzet, S; Cornel, P



Investigating the distribution of polybrominated diphenyl ethers through an Australian wastewater treatment plant.  


The aim of this study was to quantify the amount of polybrominated diphenyl ethers (PBDEs) released into the environment (biosolids, effluent) from a conventional Australian activated sludge treatment wastewater treatment plant (WWTP). The concentration of PBDE congeners was measured at various treatment stages and included four aqueous samples (raw, primary, secondary and tertiary effluents) and three sludges (primary, secondary and lime stabilized biosolids), collected at three sampling events over the course of the experiment (29 days). Semi-permeable membrane devices (SPMDs) were also installed for the duration of the experiment, the first time that SPMDs have been used to measure PBDEs in a WWTP. Over 99% of the PBDEs entering the WWTP were removed through the treatment processes, principally by sedimentation. The main congeners detected were BDE 47, 99 and 209, which are characteristic of the two major commercial formulations viz penta-BDE and deca-BDE. All the PBDE congeners measured were highly correlated with each other, suggesting a similar origin. In this case, the PBDEs are thought to be from domestic sources since domestic wastewater is the main contribution to the in-flow (approximately 95%). The mean concentration of SigmaPBDEs in chemically stabilized sewage sludge (biosolids) was 300microg kg(-1) dry weight. It is calculated that 2.3+/-0.3kg of PBDEs are disposed of each year with biosolids generated from the WWTP. If all Australian sewage sludge is contaminated to at least this concentration then at least 110kg of PBDEs are associated with Australian sewage sludge annually. Less than 10g are released annually into the environment via ocean outfall and field irrigation; this level of contamination is unlikely to pose risk to humans or the environment. The environmental release of treated effluent and biosolids is not considered a large source of PBDE environmental emissions compared to the quantities used annually in Australia. PMID:20116086

Clarke, Bradley O; Porter, Nichola A; Symons, Robert K; Marriott, Philip J; Stevenson, Gavin J; Blackbeard, Judy R



MIUS wastewater technology evaluation  

NASA Technical Reports Server (NTRS)

A modular integrated utility system wastewater-treatment process is described. Research in the field of wastewater treatment is reviewed, treatment processes are specified and evaluated, and recommendations for system use are made. The treatment processes evaluated are in the broad categories of preparatory, primary, secondary, and tertiary treatment, physical-chemical processing, dissolved-solids removal, disinfection, sludge processing, and separate systems. Capital, operating, and maintenance costs are estimated, and extensive references are given.

Poradek, J. C.



Performance assessment of AS-SBR and UF-MBR for hotel wastewater treatment.  


A large number of tourist structures in Venice (Italy) have small sized on-site treatment systems for their wastewater. Due to its historical characteristics, the city has no public sewerage system and untreated hotel wastewater represents a serious hazard for its lagoon environment. This study focused on the wastewater facilities installed in two hotels adopting an Activated Sludge Sequencing Batch Reactor (AS-SBR) and an Ultra-Filtration Membrane Biological Reactor (UF-MBR). Their performance was checked in terms of both traditional physico-chemical and ecotoxicological parameters, the importance of which has recently been recognised by EU regulatory dispositions and OSPAR indications. Acute and sub-chronic endpoints were both considered on a whole effluent toxicity basis by means of Vibrio fischeri and Crassostrea gigas, respectively. The two months monitoring survey evidenced that the UF-MBR was more efficient than the AS-SBR in providing high-quality discharges under both chemical and ecotoxicological viewpoints. PMID:19809133

Libralato, G; Volpi Ghirardini, A; Avezzù, F



Treatment and valorisation of winery wastewater by a new biophysical process (ECCF).  


Taking account of the high specificity of the organic load of winery effluents, a new biophysical treatment using the stripping of ethanol combined with a final concentration by evaporation has been studied. Two options are proposed: full treatment and pre-treatment. The study of the composition of winery wastewater has shown the large, dominant part of ethanol in the organic load (75 to 99% of the COD). According to a linear correlation between COD and ethanol concentration, the determination of ethanol concentration can be used to estimate the organic load of winery wastewater. Full treatment by stripping and concentration at a pilot plant allows the separation of the wastewater into highly purified water (COD elimination > 99%), a concentrated alcoholic solution usable as bio-fuel and a concentrated by-product. Stripping alone represents an advantageous pre-treatment of winery wastewater. The purification rate reaches 78 to 85% and ethanol is recovered. The process facilitates discharge into a sewage system in view of treatment with domestic effluents and can also improve the efficiency of overloaded or old purification plants. The economical approach of this method demonstrates its competitiveness in comparison with biological treatments: low energy consumed, no sludge. PMID:15771104

Colin, T; Bories, A; Sire, Y; Perrin, R



Author's personal copy Effectiveness of domestic wastewater treatment using microbial fuel cells  

E-print Network

Author's personal copy Effectiveness of domestic wastewater treatment using microbial fuel cells 2009 Available online 5 September 2009 Keywords: Domestic wastewater treatment Energy recovery for domestic wastewater treatment are power savings, low solids production, and higher treatment efficiency. Ã?


Occurrence of eight household micropollutants in urban wastewater and their fate in a wastewater treatment plant. Statistical evaluation.  


The occurrence in urban wastewater of eight micropollutants (erythromycin, ibuprofen, 4-nonylphenol (4-NP), ofloxacin, sucralose, triclosan, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) originating from household activities and their fate in a biological wastewater treatment plant (WWTP) were investigated. Their concentrations were assessed in the liquid and solid phases (sewage particulate matter and wasted activated sludge (WAS)) by liquid chromatography-tandem mass spectrometry. The analysis of sewage from two different urban catchments connected to the WWTP showed a specific use of ofloxacin in the mixed catchment due to the presence of a hospital, and higher concentrations of sucralose in the residential area. The WWTP process removed over 90% of ibuprofen and triclosan from wastewater, while only 25% of ofloxacin was eliminated. Erythromycin, sucralose and PFOA were not removed from wastewater, the influent and effluent concentrations remaining at about 0.7 ?g/L, 3 ?g/L and 10 ng/L respectively. The behavior of PFOS and 4-nonylphenol was singular, as concentrations were higher at the WWTP outlet than at its inlet. This was probably related to the degradation of some of their precursors (such as alkylphenol ethoxylates and polyfluorinated compounds resulting in 4-NP and PFOS, respectively) during biological treatment. 4-NP, ofloxacin, triclosan and perfluorinated compounds were found adsorbed on WAS (from 5 ng/kg for PFOA to 1.0mg/kg for triclosan). The statistical methods (principal component analysis and multiple linear regressions) were applied to examine relationships among the concentrations of micropollutants and macropollutants (COD, ammonium, turbidity) entering and leaving the WWTP. A strong relationship with ammonium indicated that some micropollutants enter wastewater via human urine. A statistical analysis of WWTP operation gave a model for estimating micropollutant output from the WWTP based on a measurement of macropollution parameters. PMID:24631609

Pasquini, Laure; Munoz, Jean-François; Pons, Marie-Noëlle; Yvon, Jacques; Dauchy, Xavier; France, Xavier; Le, Nang Dinh; France-Lanord, Christian; Görner, Tatiana



Land disposal of water treatment plant sludge -- A feasibility analysis  

SciTech Connect

In this study, the following alternative disposal methods for the Buffalo Pound Water Treatment Sludge were evaluated: landfilling, discharge into sanitary sewers, long-term lagooning, use in manufacturing, co-composting, alum recovery and land application. Land application was chosen at the best disposal alternative. Preliminary design resulted in a 1% dry alum sludge loading rate (25 tonnes/ha), requiring 35 ha over a nine-year period and a phosphorus fertilizer supplement of about 50kg/ha.

Viraraghavan, T.; Multon, L.M.; Wasylenchuk, E.J.



Performance evaluation of various aerobic biological systems for the treatment of domestic wastewater at low temperatures.  


Studies were undertaken on the performance evaluation of three different types of aerobic reactors, namely, activated sludge process, fluidized bed reactor and submerged bed reactor. Initially synthetic wastewater was used for stabilizing the system and later domestic wastewater of IIT Madras was used as the feed for the biological systems. The hydraulic retention time was maintained as 24 h. The seed sludge was collected from IIT Madras sewage treatment plant. The inlet COD to the reactors with synthetic wastewater was 1,000 +/- 20 mg/L and with real wastewater, it was 150 to 350 mg/L. The performance of the reactors was evaluated based on the soluble COD and nitrogen removal efficiency. The pH, temperature, dissolved oxygen (DO) and mixed liquid suspended solid (MLSS) concentration were measured periodically. The reactors were acclimatized at 35 degrees C in batch mode and changed to continuous mode at 30 degrees C. After the systems attained its steady state at a particular temperature, the temperature was reduced from 35 degrees C to 5 degrees C stepwise, with each step of 5 degrees C. The start-up time for submerged bed reactor was slightly more than fluidized and conventional activated sludge process.The COD removal efficiency of the three reactors was higher with synthetic wastewaters as compared to actual domestic wastewater. Submerged bed reactor was more robust and efficient as compared to activated sludge and fluidized bed reactors. The COD removal efficiency of the reactors was relatively good until the operating temperature was maintained at 15 degrees C or above. At 10 degrees C, submerged bed reactor was able to achieve 40% COD removal efficiency whereas; the fluidized bed and conventional ASP reactors were showing only 20% COD removal efficiency. At 5 degrees C, almost all the systems failed. Submerged bed reactor showed around 20% COD removal efficiency. However, this reactor was able to regain its 90% of original efficiency, once the temperature was raised to 10 degrees C. At higher temperatures, the nitrification efficiency of the reactors was above 80-90%. As the temperature reduced the nitrification efficiency has reduced drastically. In summary, submerged bed reactors seems to be a better option for treating domestic wastewaters at low temperature regions. PMID:18776617

Sundaresan, N; Philip, L



Determination of changes in wastewater quality through a treatment works using fluorescence spectroscopy.  


Fluorescence spectroscopy was used to characterize municipal wastewater at various stages of treatment in order to understand how its fluorescence signature changes with treatment and how the signal relates to biochemical oxygen demand (BOD) and chemical oxygen demand (COD). The impact of size fractionation on the fluorescence signal was also investigated. Fluorescence measurements were taken for unfiltered and filtered (0.45 and 0.20 microm) samples of crude, settled and secondary treated wastewater (activated sludge and trickling filter), and final effluent. Good correlations were observed for unfiltered, diluted wastewater samples between BOD and fluorescence intensity at excitation 280 nm, emission 350 nm (Peak T1) (r = 0.92) and between COD and Peak T1 intensity (r = 0.85). The majority of the T1 and T2 signal was found to be derived from the <0.20 microm fraction. Initial results indicate that fluorescence spectroscopy, and changes in Peak T1 intensity in particular, could be used for continuous, real-time wastewater quality assessment and proce