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Sample records for advanced sludge treatment

  1. Advanced sewage treatment process with excess sludge reduction and phosphorus recovery.

    PubMed

    Saktaywin, W; Tsuno, H; Nagare, H; Soyama, T; Weerapakkaroon, J

    2005-03-01

    An advanced sewage treatment process has been developed, in which excess sludge reduction by ozonation and phosphorus recovery by crystallization process are incorporated to a conventional anaerobic/oxic (A/O) phosphorus removal process. The mathematical model was developed to describe the mass balance principal at a steady state of this process. Sludge ozonation experiments were carried out to investigate solubilization characteristics of sludge and change in microbial activity by using sludge cultured with feed of synthetic sewage under A/O process. Phosphorus was solubilized by ozonation as well as organics, and acid-hydrolyzable phosphorus (AHP) was the most part of solubilized phosphorus for phosphorus accumulating organisms (PAOs) containing sludge. At solubilization of 30%, around 70% of sludge was inactivated by ozonation. The results based on these studies indicated that the proposed process configuration has potential to reduce the excess sludge production as well as to recover phosphorus in usable forms. The system performance results show that this system is practical, in which 30% of solubilization degree was achieved by ozonation. In this study, 30% of solubilization was achieved at 30 mgO(3)/gSS of ozone consumption.

  2. Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?

    PubMed

    Cristale, Joyce; Ramos, Dayana D; Dantas, Renato F; Machulek Junior, Amilcar; Lacorte, Silvia; Sans, Carme; Esplugas, Santiago

    2016-01-01

    This study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67 µg L(-1) to 150 µg L(-1). During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980 ng g(-1) dw. Chlorinated compounds tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2,3-dichloropropyl) phosphate (TDCPP) were not removed by the conventional activated sludge treatment and they were released by the effluents at approximately the same inlet concentration. On the contrary, aryl compounds tris(methylphenyl) phosphate (TMPP) and 2-ethylhexyl diphenyl phosphate (EHDP) together with alkyl tris(2-ethylhexyl) phosphate (TEHP) were not detected in any of the effluents. Advanced oxidation processes (UV/H2O2 and O3) were applied to investigate the degradability of recalcitrant OPFRs in WWTP effluents. Those detected in the effluent sample (TCEP, TCIPP, TDCPP, tributyl phosphate (TNBP), tri-iso-butyl phosphate (TIBP) and tris(2-butoxyethyl) phosphate (TBOEP)) had very low direct UV-C photolysis rates. TBOEP, TNBP and TIBP were degraded by UV/H2O2 and O3. Chlorinated compounds TCEP, TDCPP and TCIPP were the most recalcitrant OPFR to the advanced oxidation processes applied. The study provides information on the partitioning and degradability pathways of OPFR within conventional activated sludge WWTPs.

  3. Recent advances in membrane bio-technologies for sludge reduction and treatment.

    PubMed

    Wang, Zhiwei; Yu, Hongguang; Ma, Jinxing; Zheng, Xiang; Wu, Zhichao

    2013-12-01

    This paper is designed to critically review the recent developments of membrane bio-technologies for sludge reduction and treatment by covering process fundamentals, performances (sludge reduction efficiency, membrane fouling, pollutant removal, etc.) and key operational parameters. The future perspectives of the hybrid membrane processes for sludge reduction and treatment are also discussed. For sludge reduction using membrane bioreactors (MBRs), literature review shows that biological maintenance metabolism, predation on bacteria, and uncoupling metabolism through using oxic-settling-anaerobic (OSA) process are promising ways that can be employed in full-scale applications. Development of control methods for worm proliferation is in great need of, and a good sludge reduction and MBR performance can be expected if worm growth is properly controlled. For lysis-cryptic sludge reduction method, improvement of oxidant dispersion and increase of the interaction with sludge cells can enhance the lysis efficiency. Green uncoupler development might be another research direction for uncoupling metabolism in MBRs. Aerobic hybrid membrane system can perform well for sludge thickening and digestion in small- and medium-sized wastewater treatment plants (WWTPs), and pilot-scale/full-scale applications have been reported. Anaerobic membrane digestion (AMD) process is a very competitive technology for sludge stabilization and digestion. Use of biogas recirculation for fouling control can be a powerful way to decrease the energy requirements for AMD process. Future research efforts should be dedicated to membrane preparation for high biomass applications, process optimization, and pilot-scale/full-scale tracking research in order to push forward the real and wide applications of the hybrid membrane systems for sludge minimization and treatment.

  4. Advanced thermal hydrolysis: optimization of a novel thermochemical process to aid sewage sludge treatment.

    PubMed

    Abelleira, Jose; Pérez-Elvira, Sara I; Portela, Juan R; Sánchez-Oneto, Jezabel; Nebot, Enrique

    2012-06-05

    The aim of this work was to study in depth the behavior and optimization of a novel process, called advanced thermal hydrolysis (ATH), to determine its utility as a pretreatment (sludge solubilization) or postreatment (organic matter removal) for anaerobic digestion (AD) in the sludge line of wastewater treatment plants (WWTPs). ATH is based on a thermal hydrolysis (TH) process plus hydrogen peroxide (H(2)O(2)) addition and takes advantage of a peroxidation/direct steam injection synergistic effect. On the basis of the response surface methodology (RSM) and a modified Doehlert design, an empirical second-order polynomial model was developed for the total yield of: (a) disintegration degree [DD (%)] (solubilization), (b) filtration constant [F(c) (cm(2)/min)] (dewaterability), and (c) organic matter removal (%). The variables considered were operation time (t), temperature reached after initial heating (T), and oxidant coefficient (n = oxygen(supplied)/oxygen(stoichiometric)). As the model predicts, in the case of the ATH process with high levels of oxidant, it is possible to achieve an organic matter removal of up to 92%, but the conditions required are prohibitive on an industrial scale. ATH operated at optimal conditions (oxygen amount 30% of stoichiometric, 115 °C and 24 min) gave promising results as a pretreatment, with similar solubilization and markedly better dewaterability levels in comparison to those obtained with TH at 170 °C. The empirical validation of the model was satisfactory.

  5. Liming as an advanced treatment for sludge sanitisation: helminth eggs elimination--Ascaris eggs as model.

    PubMed

    Capizzi-Banas, S; Deloge, M; Remy, M; Schwartzbrod, J

    2004-01-01

    The presence of helminth eggs (Ascaris eggs) in sewage sludge may constitute a sanitary risk when used as agricultural fertiliser. Sanitisation of sewage sludge can be achieved by treatment with quick lime, a process that destroys sludge pathogens in two ways: pH increase and temperature rise. Among the pathogens of epidemiological relevance, Ascaris eggs are the most resistant to liming, and, hence, may serve as indicators of hygienic quality of biosolids. This research aims at defining, between 50 degrees C and 60 degrees C, the time required in the case of limed sludge to obtain a product with a negligible level of viable Ascaris eggs. To achieve this objective, investigations on inactivation kinetics of Ascaris eggs were conducted in the following products: contaminated milk of lime; naturally contaminated sludge treated with slaked lime and heat; naturally contaminated sludge treated with quick lime; and sludge treated at full scale with quick lime. For the inactivation kinetics where a negligible level of Ascaris eggs was reached, the inactivation threshold was determined. Depending on the experimental situation, the inactivation threshold period was found to fluctuate between 5 and 75 min at 55 degrees C and between 1 and 8 min at 60 degrees C.

  6. Sludge treatment studies

    SciTech Connect

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

    1997-06-01

    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.

  7. Sewage sludge treatment system

    NASA Technical Reports Server (NTRS)

    Kalvinskas, John J. (Inventor); Mueller, William A. (Inventor)

    1976-01-01

    Raw sewage may be presently treated by mixing screened raw sewage with activated carbon. The mixture is then allowed to stand in a first tank for a period required to settle the suspended matter to the bottom of the tank as a sludge. Thereafter, the remaining liquid is again mixed with activated carbon and the mixture is transferred to a secondary settling tank, where it is permitted to stand for a period required for the remaining floating material to settle as sludge and for adsorption of sewage carbon as well as other impurities to take place. The sludge from the bottom of both tanks is removed and pyrolyzed to form activated carbon and ash, which is mixed with the incoming raw sewage and also mixed with the liquid being transferred from the primary to the secondary settling tank. It has been found that the output obtained by the pyrolysis process contains an excess amount of ash. Removal of this excess amount of ash usually also results in removing an excess amount of carbon thereby requiring adding carbon to maintain the treatment process. By separately pyrolyzing the respective sludges from the first and second settling tanks, and returning the separately obtained pyrolyzed material to the respective first and second tanks from which they came, it has been found that the adverse effects of the excessive ash buildup is minimized, the carbon yield is increased, and the sludge from the secondary tank can be pyrolyzed into activated carbon to be used as indicated many more times than was done before exhaustion occurs.

  8. Enhanced nitrogen and phosphorus removal by an advanced simultaneous sludge reduction, inorganic solids separation, phosphorus recovery, and enhanced nutrient removal wastewater treatment process.

    PubMed

    Yan, Peng; Guo, Jin-Song; Wang, Jing; Chen, You-Peng; Ji, Fang-Ying; Dong, Yang; Zhang, Hong; Ouyang, Wen-juan

    2015-05-01

    An advanced wastewater treatment process (SIPER) was developed to simultaneously decrease sludge production, prevent the accumulation of inorganic solids, recover phosphorus, and enhance nutrient removal. The feasibility of simultaneous enhanced nutrient removal along with sludge reduction as well as the potential for enhanced nutrient removal via this process were further evaluated. The results showed that the denitrification potential of the supernatant of alkaline-treated sludge was higher than that of the influent. The system COD and VFA were increased by 23.0% and 68.2%, respectively, after the return of alkaline-treated sludge as an internal C-source, and the internal C-source contributed 24.1% of the total C-source. A total of 74.5% of phosphorus from wastewater was recovered as a usable chemical crystalline product. The nitrogen and phosphorus removal were improved by 19.6% and 23.6%, respectively, after incorporation of the side-stream system. Sludge minimization and excellent nutrient removal were successfully coupled in the SIPER process.

  9. A Technology of Wastewater Sludge Treatment

    NASA Astrophysics Data System (ADS)

    Gizatulin, R. A.; Senkus, V. V.; Valueva, A. V.; Baldanova, A. S.; Borovikov, I. F.

    2016-04-01

    At many communities, industrial and agricultural enterprises, treatment and recycling of wastewater sludge is an urgent task as the sludge is poured and stored in sludge banks for many years and thus worsens the ecology and living conditions of the region. The article suggests a new technology of wastewater sludge treatment using water-soluble binder and heat treatment in microwave ovens.

  10. Sewage sludge treatment with lime.

    PubMed

    Herbst, B

    2000-01-01

    The article describes the application of lime as a method for treatment and hygienisation of sewage sludges with lime products such as quicklime, slake lime and dolomitic lime. As a result of the increase in temperature and pH-value during sludge and lime mixing most pathogenic vectors of disease (i.e. bacteria, worms, viruses and parasites) are reduced in concentration and viability to manufacture a safe product for further application on agricultural land.

  11. Microwave Supported Treatment of Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Janíček, František; Perný, Milan; Šály, Vladimír; Giemza, Markus; Hofmann, Peter

    2016-07-01

    This work is focused on microwave treatment of sewage sludge. The aim of our experiments was to investigate the impact of microwave radiation upon different sewage sludge parameters such as concentration of nitrates and nitrites, phosphates, COD (Chemical Oxygen Demand), SVI (Sludge Volume Index) and the microscopic structure of sludge. The experiments with microwave irradiation of sewage sludge indicate that moderate microwave power causes visible effects on the chemical, physical and biological properties of the sludge. The calculation of profitability and energy efficiency is also presented.

  12. Treatment of Dredged Sludge By Mechanical Dehydration,

    DTIC Science & Technology

    there is an urgent need to reduce both the volume of dredged sludge and the size of the disposal area. This mechanical method is different from the...conventional engineering dehydration by loading, consolidation, and drainage in that the dredged sludge is separated into sludge cakes and clean water...turbidity in water. This mechanical sludge treatment technique can be most efficient when used in combination with a pump dredge. This method offers

  13. Design of automated oil sludge treatment unit

    NASA Astrophysics Data System (ADS)

    Chukhareva, N.; Korotchenko, T.; Yurkin, A.

    2015-11-01

    The article provides the feasibility study of contemporary oil sludge treatment methods. The basic parameters of a new resource-efficient oil sludge treatment unit that allows extracting as much oil as possible and disposing other components in efficient way have been outlined. Based on the calculation results, it has been revealed that in order to reduce the cost of the treatment unit and the expenses related to sludge disposal, it is essential to apply various combinations of the existing treatment methods.

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

    PubMed

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

    2013-08-01

    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.

  15. Advanced lignin-acrylamide water treatment agent by pulp and paper industrial sludge: synthesis, properties and application.

    PubMed

    Rong, Hongyan; Gao, Baoyu; Zhao, Yanxia; Sun, Shenglei; Yang, Zhonglian; Wang, Yan; Yue, Qinyan; Li, Qian

    2013-12-01

    A novel flocculant LA (lignin-acrylamide polymer), which was used as aid for aluminum sulfate and polyaluminum chloride in this study, was prepared by grafting acrylamide onto lignin that deriving from pulp and papermaking sludge. Physicochemical properties of LA were measured by X-ray photoelectron spectroscopy and scanning electron microscopy. The experimental outcome indicated acrylamide was grafted onto the lignin backbone successfully. The effects of LA addition were evaluated on coagulation performance and floc characteristics as a function of aluminum (Al) dosage, such as floc size, growth rate, strength and recoverability. Effects of different dosing sequences, Al dosed first and LA dosed first, were also investigated. LA used as coagulant aid markedly enhanced the removal efficiency of turbidity and dissolved organic carbon, especially at low Al dosages. The dissolved organic carbon removal efficiencies of aluminum sulfate and polyaluminum chloride at the Al dosage range selected in this study were improved more than 30% and 5% by LA, respectively. LA dramatically enlarged floc size and it was in the order: Al dosed first > LA dosed first > Al. Floc strength and recoverability were also improved by LA. LA played a significant role in charge neutralization, adsorption and bridging in floc formation.

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

    PubMed

    Bauerfeld, Katrin

    2014-01-01

    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.

  17. Revised sampling campaigns to provide sludge for treatment process testing

    SciTech Connect

    PETERSEN, C.A.

    1999-02-18

    The purpose of this document is to review the impact to the sludge sampling campaigns planned for FY 1999 given the recent decision to delete any further sludge sampling in the K West Basin. Requirements for Sludge sample material for Sludge treatment process testing are reviewed. Options are discussed for obtaining the volume sample material required and an optimized plan for obtaining this sludge is summarized.

  18. K Basin sludge treatment process description

    SciTech Connect

    Westra, A.G.

    1998-08-28

    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).

  19. Thermophilic sludge digestion improves energy balance and nutrient recovery potential in full-scale municipal wastewater treatment plants.

    PubMed

    De Vrieze, Jo; Smet, Davey; Klok, Jacob; Colsen, Joop; Angenent, Largus T; Vlaeminck, Siegfried E

    2016-10-01

    The conventional treatment of municipal wastewater by means of activated sludge is typically energy demanding. Here, the potential benefits of: (1) the optimization of mesophilic digestion; and (2) transitioning to thermophilic sludge digestion in three wastewater treatment plants (Tilburg-Noord, Land van Cuijk and Bath) in the Netherlands is evaluated, including a full-scale trial validation in Bath. In Tilburg-Noord, thermophilic sludge digestion covered the energy requirements of the plant (102%), whereas 111% of sludge operational treatment costs could be covered in Bath. Thermophilic sludge digestion also resulted in a strong increase in nutrient release. The potential for nutrient recovery was evaluated via: (1) stripping/absorption of ammonium; (2) autotrophic removal of ammonium via partial nitritation/anammox; and (3) struvite precipitation. This research shows that optimization of sludge digestion may lead to a strong increase in energy recovery, sludge treatment costs reduction, and the potential for advanced nutrient management in full-scale sewage treatment plants.

  20. Microplastics in Sewage Sludge: Effects of Treatment.

    PubMed

    Mahon, A M; O'Connell, B; Healy, M G; O'Connor, I; Officer, R; Nash, R; Morrison, L

    2017-01-17

    Waste water treatment plants (WWTPs) are receptors for the cumulative loading of microplastics (MPs) derived from industry, landfill, domestic wastewater and stormwater. The partitioning of MPs through the settlement processes of wastewater treatment results in the majority becoming entrained in the sewage sludge. This study characterized MPs in sludge samples from seven WWTPs in Ireland which use anaerobic digestion (AD), thermal drying (TD), or lime stabilization (LS) treatment processes. Abundances ranged from 4196 to 15 385 particles kg(-1) (dry weight). Results of a general linear mixed model (GLMM) showed significantly higher abundances of MPs in smaller size classes in the LS samples, suggesting that the treatment process of LS shears MP particles. In contrast, lower abundances of MPs found in the AD samples suggests that this process may reduce MP abundances. Surface morphologies examined using scanning electron microscopy (SEM) showed characteristics of melting and blistering of TD MPs and shredding and flaking of LS MPs. This study highlights the potential for sewage sludge treatment processes to affect the risk of MP pollution prior to land spreading and may have implications for legislation governing the application of biosolids to agricultural land.

  1. Microwave oxidation treatment of sewage sludge.

    PubMed

    Lo, Kwang V; Srinivasan, Asha; Liao, Ping H; Bailey, Sam

    2015-01-01

    Microwave-oxidation treatment of sewage sludge using various oxidants was studied. Two treatment schemes with a combination of hydrogen peroxide and ozone were examined: hydrogen peroxide and ozone were introduced into the sludge simultaneously, followed by microwave heating. The other involved the ozonation first, and then the resulting solution was subjected to microwave and hydrogen peroxide treatment. The set with ozonation followed by hydrogen peroxide plus microwave heating yielded higher soluble materials than those of the set with hydrogen peroxide plus ozone first and then microwave treatment. No settling was observed for all treatments in the batch operation, except ozone/microwave plus hydrogen peroxide set at 120°C. The pilot-scale continuous-flow 915 MHz microwave study has demonstrated that microwave-oxidation process is feasible for real-time industrial application. It would help in providing key data for the design of a full-scale system for treating sewage sludge and the formulation of operational protocols.

  2. LAND APPLICATION AND SLUDGE TREATMENT

    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...

  3. Microwave treatment of industrial waste water sludge

    SciTech Connect

    Goodwill, J.E.

    1995-12-31

    Steel mills in the US generate approximately 1 million tons of sludge annually. This is mainly a residue of cooling water, lubricating oils, and metallic fines from hot strip rolling mills and other operations. At present the separation of sludge from the liquid requires large settling tanks, takes several hours of time, and produces a residue that must be disposed of at high cost. The EPRI Center for Materials Production, sponsored by the Electric Power Research Institute (EPRI), has supported development of a microwave based treatment system. This new process, developed by Carnegie Mellon Research Institute of Carnegie Mellon University, and patented by EPRI is 30 times faster, requires 90% less space, and eliminates land-filling by producing materials of value. Electricity usage is only 0.5 kWh per gallon. A review by the American Iron and Steel Institute (AISI) Waste Recycle Technology Task Force of this and various other approaches, concluded that further work on the microwave technology was justified. Subsequently additional work was undertaken toward optimizing the process for treating metallic waste sludges containing lime and polymers. This effort cofunded by EPRI and the AISI was successfully concluded in late 1994. Next a two phase program is being developed to commercialize the process. Phase 1 will demonstrate the technology in a large scale batch mode. Phase 2 will be a commercial scale continuous installation at a steel mill site projected for 1996.

  4. Supercritical water oxidation treatment of textile sludge.

    PubMed

    Zhang, Jie; Wang, Shuzhong; Li, Yanhui; Lu, Jinling; Chen, Senlin; Luo, XingQi

    2016-10-17

    In this work, we studied the supercritical water oxidation (SCWO) of the textile sludge, the hydrothermal conversion of typical textile compounds and the corrosion properties of stainless steel 316. Moreover, the influence mechanisms of NaOH during these related processes were explored. The results show that decomposition efficiency for organic matter in liquid phase of the textile sludge was improved with the increment of reaction temperature or oxidation coefficient. However, the organic substance in solid phase can be oxidized completely in supercritical water. Serious coking occurred during the high pressure water at 250-450°C for the Reactive Orange 7, while at 300 and 350°C for the polyvinyl alcohol. The addition of NaOH not only accelerated the destruction of organic contaminants in the SCWO reactor, but effectively inhibited the dehydration conversion of textile compounds during the preheating process, which was favorable for the treatment system of textile sludge. The corrosion experiment results indicate that the stainless steel 316 could be competent for the body materials of the reactor and the heat exchangers. Furthermore, there was prominent enhancement of sodium hydroxide for the corrosion resistance of 316 in subcritical water. On the contrary the effect was almost none during SCWO.

  5. Sludge recycle and reuse in acid mine drainage treatment

    SciTech Connect

    Keefer, G.B.; Sack, W.A.

    1983-03-01

    Neutralization of acid mine drainage produces vast quantities of iron-rich sludge, and large quantities of unused lime remain in the sludge after treatment. In a study in which sludge was recycled to increase lime utilization, sludge was mixed with raw acid mine drainage and settled out in an intermediate clarifier. The clarifier supernatant was then treated by lime addition, aeration and sedimentation. The low-pH sludge was withdrawn from the intermediate clarifier. The iron was recovered by acidification and used as wastewater coagulant. The recycle scheme resulted in a 30% decrease in lime requirements, and the resultant coagulant performed well when compared with stock iron coagulant solutions.

  6. Sludge Lagoons. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Sharman, Ronald M.

    This lesson describes three different types of sludge lagoons: (1) drying lagoons; (2) facultative lagoons; and (3) anaerobic lagoons. Normal operating sequence and equipment are also described. The lesson is designed to be used in sequence with the complete Sludge Treatment and Disposal Course #166 or as an independent lesson. The instructor's…

  7. Digital image processing and analysis for activated sludge wastewater treatment.

    PubMed

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

    2015-01-01

    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.

  8. SLUDGE TREATMENT PROJECT PHASE 1 SLUDGE STORAGE OPTIONS ASSESSMENT OF T PLANT VERSUS ALTERNATE STORAGE FACILITY

    SciTech Connect

    RUTHERFORD WW; GEUTHER WJ; STRANKMAN MR; CONRAD EA; RHOADARMER DD; BLACK DM; POTTMEYER JA

    2009-04-29

    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

  9. Advanced Activated Sludge. Training Module 2.117.4.77.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with operation of activated sludge wastewater treatment plants. Included are objectives, instructor guides, student handouts and transparency masters. This is the third level of a three module series and considers design and operation…

  10. Sludge reduction by lumbriculus variegatus in Ahvas wastewater treatment plant

    PubMed Central

    2012-01-01

    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

  11. Sludge reduction by lumbriculus variegatus in Ahvas wastewater treatment plant.

    PubMed

    Basim, Yalda; Farzadkia, Mahdi; Jaafarzadeh, Nematollah; Hendrickx, Tim

    2012-08-02

    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.

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

    PubMed

    Marti, Erica J; Batista, Jacimaria R

    2014-02-01

    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

  13. Dewatering of floated oily sludge by treatment with rhamnolipid.

    PubMed

    Long, Xuwei; Zhang, Guoliang; Han, Li; Meng, Qin

    2013-09-01

    Oily sludge dewatering is practically needed prior to sludge treatments. However, the conventional use of physical treatments with or without chemical conditionings presented poor feasibility in industrial applications due to either poor cost-efficiency or lacking environmental friendliness. In this paper, biosurfactant rhamnolipid was for the first time applied for dewatering of oily sludge. Rhamnolipid treatments under the concentration of 300-1000 mg/L, pH of 5-7 and temperature of 10-60 °C could directly separate 50-80% of water from the stable oily sludge. And both mono-rhamnolipid and di-rhamnolipid were identified to be of equivalent dewatering ability, which is closely related to their equivalent performance in breaking the emulsified oil droplets. Demulsification was found to be involved in settling water from oily sludge. Furthermore, the effectiveness of rhamnolipid was further demonstrated at pilot scale (1000 L) treatment of oily sludge. After pilot treatment, the settled water with residual oil of 10 mg/L and soluble COD of about 800 mg/L could be directly effluxed into the biotreatment system while the concentrated oil sludge with a reduced volume by 60-80% can be pumped into coking tower, achieving completely harmless treatment. It seems that rhamnolipid as dewatering agent was of great prospects in the industrial dewatering of oily sludge.

  14. Characterization of drinking water treatment sludge after ultrasound treatment.

    PubMed

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

    2015-05-01

    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 5 W/ml for 30 min ultra-sonication (specific energy of 1590 kWh/kg TS). 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 1 W/ml), while decrease as ultra-sonication prolongs at higher energy densities (3 and 5 W/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.

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

    SciTech Connect

    Danny M. McDonald; John A. Webb; Jeff Taylor

    2006-03-15

    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.

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

    PubMed

    McDonald, Danny M; Webb, John A; Taylor, Jeff

    2006-03-15

    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.

  17. Relationship between enhanced dewaterability and structural properties of hydrothermal sludge after hydrothermal treatment of excess sludge.

    PubMed

    Wang, Liping; Li, Aimin; Chang, Yuzhi

    2017-04-01

    Hydrothermal treatment is an effective method to enhance the deep dewaterability of excess sludge with low energy consumption. In this study, an insight into the relationship between enhanced dewaterability and structural properties of the produced hydrothermal sludge was presented, aiming at better understanding the effect of hydrothermal process on excess sludge dewatering performance. The results indicated that hydrothermal effect induced the transformation of surface water to interstitial and free water by lowering the binding strength between adjacent water and solid particles and that free water became the main form for moisture existence in hydrothermal sludge as temperature was higher than 180 °C. Increase in temperature of hydrothermal treatment generated a significant size reduction of sludge flocs but treated sludge with a higher rigidity, which not only strengthened the network of hydrothermal sludge but also destroyed the binding of EPS with water. Hydrothermal process caused crevice and pore structures of excess sludge to disappear gradually, which was a main driving force of water removal as temperature was below 150 °C. With the temperature of hydrothermal treatment exceeding 180 °C, the morphology of hydrothermal sludge became rough which linked closely to the solid precipitation of condensation polymerization, and further became smooth at higher temperature (210 °C) due to the coal-like structures with higher aromaticities, indicating that hydrothermal reaction pathways began to play a main role in enhanced dewaterability. Hydrothermal treatment led to more alkyl and aromatic carbon, but lower O-alkyl, carboxyl and carbonyl carbon.

  18. Numerical and experimental evaluation of continuous ultrasonic sludge treatment system.

    PubMed

    Zhou, Cuihong; Huang, Xintong; Jin, Yanping; Li, Ge

    2016-09-01

    Ultrasonic disintegration is a very promising sludge pretreatment method that leverages the cavitation effect to produce extreme physical environments characterized by high temperatures and high pressures. This process disintegrates sludge structure features, promotes sludge dewatering, and aides resource recovery. This paper presents a newly designed continuous ultrasonic sludge treatment device. The characteristics of the ultrasonic wave propagated in the activated sludge were simulated, with the results showing that at lower frequencies, the acoustic pressure energy distribution exhibits more local concentrations, whereas at 80kHz, the energy distribution is relatively uniform as a result of the interference of standing waves. Subsequently, activated sludge was ultrasonically treated with different exposure times and frequencies. The sludge's capillary suction time, particle size, and moisture content were measured. The results showed different trends for each of the investigated parameters. The dewatering performance was best when the exposure time was 5-10s. Finally, different substances were added to the ultrasonically treated sludge to analyze the effects of ultrasonic treatment on anaerobic digestion. The gas production rate was higher when glucose was the added substance than it was for yeast. The highest total concentration of produced gas, including both hydrogen and methane, was 34% for an ultrasonic input power of 200W at a 25kHz frequency, an exposure time of 20s, and with 30g of added glucose. The gas production rate was found to be higher at the lower frequency when frequency was the only variable. These experiments demonstrate that ultrasonic treatment can change the structure of sludge particles and the moisture content of the sludge, improving sludge dewatering performance. Furthermore, after ultrasonic treatment can improve gas production.

  19. Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

    SciTech Connect

    Delegard, Calvin H.; Schmidt, Andrew J.; Thornton, Brenda M.

    2007-03-30

    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.

  20. Somatic coliphages as surrogates for enteroviruses in sludge hygienization treatments.

    PubMed

    Martín-Díaz, Julia; Casas-Mangas, Raquel; García-Aljaro, Cristina; Blanch, Anicet R; Lucena, Francisco

    2016-01-01

    Conventional bacterial indicators present serious drawbacks giving information about viral pathogens persistence during sludge hygienization treatments. This calls for the search of alternative viral indicators. Somatic coliphages' (SOMCPH) ability for acting as surrogates for enteroviruses was assessed in 47 sludge samples subjected to novel treatment processes. SOMCPH, infectious enteroviruses and genome copies of enteroviruses were monitored. Only one of these groups, the bacteriophages, was present in the sludge at concentrations that allowed the evaluation of treatment's performance. An indicator/pathogen relationship of 4 log10 (PFU/g dw) was found between SOMCPH and infective enteroviruses and their detection accuracy was assessed. The obtained results and the existence of rapid and standardized methods encourage the inclusion of SOMCPH quantification in future sludge directives. In addition, an existing real-time quantitative polymerase chain reaction (RT-qPCR) for enteroviruses was adapted and applied.

  1. Sludge.

    ERIC Educational Resources Information Center

    Tenenbaum, David

    1992-01-01

    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)

  2. Sludge pre-treatment with pulsed electric fields.

    PubMed

    Kopplow, O; Barjenbruch, M; Heinz, V

    2004-01-01

    The anaerobic stabilization process depends - among other things - on the bio-availability of organic carbon. Through pre-treatment of the sludge which leads to the destruction of micro-organisms and to the setting-free of cell content substances (disintegration), the carbon can be microbially converted better and faster. Moreover, effects on the digestion are likely. However, only little experience is available in sludge treatment with pulsed electric fields. Laboratory-scale digestion tests have been run to analyse the influence of pulsed electric fields on the properties of sludge, anaerobic degradation, sludge water reload and foaming of digesters. The results will be compared with those of other disintegration methods (high pressure homogeniser, thermal treatment). The effect of pre-treatment on the sludge is shown by the COD release. Degrees of disintegration have been achieved up to 20%. The specific energy input was high. The energy consumption has been decreased by initial improvements (pre-heating to 55 degrees C). The filament bacteria were partially destroyed. The foam reduction in the digesters was marginal. The anaerobic degradation performance has been improved in every case. The degradation rate of organic matter increased about 9%. Due to the increase of degradation, there is a higher reload of the sludge-water with COD and nitrogen compounds.

  3. Technical, economic and environmental assessment of sludge treatment wetlands.

    PubMed

    Uggetti, Enrica; Ferrer, Ivet; Molist, Jordi; García, Joan

    2011-01-01

    Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (<2000 population equivalent). The performance of full-scale STW was characterised during 2 years. Sludge dewatering increased total solids (TS) concentration by 25%, while sludge biodegradation lead to volatile solids around 45% TS and DRI(24h) between 1.1 and 1.4 gO(2)/kgTS h, suggesting a partial stabilisation of biosolids. In the economic and environmental assessment, four scenarios were considered for comparison: 1) STW with direct land application of biosolids, 2) STW with compost post-treatment, 3) centrifuge with compost post-treatment and 4) sludge transport to an intensive wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities.

  4. Sludge Generation from Ferrous/Sulfide Chromium Treatment.

    DTIC Science & Technology

    1984-08-01

    sodium bisulfite , sulfur dioxide, and sodium sulfide. While all these chemicals produce a satisfactory effluent, the quantity of sludge produced by the...34Treatment of Toxic Metal Wastewaters by Alkaline Ferrous Sulfate and Sodium Sulfied for Chromium Reduction, Precipitation and Coagulation," Pro... sodium sulfide and ferrous chloride (9:1 ratio) at pH 8.0 rapidly reduced hexavalent chromium and produced approximately one-fourth the sludge (on a

  5. [Impacts of alkaline thermal treatment on characteristics of sludge from sewage treatment plant].

    PubMed

    Yang, Shi-Dong; Chen, Xia; Liu, Cao; Xiao, Ben-Yi

    2015-02-01

    Alkaline thermal treatment is an important pretreatment method for sewage sludge. In this paper, in order to optimize the alkaline thermal treatment conditions for sludge pretreatment, four pretreatment parameters ( sludge concentration, pH, temperature and treatment time) were investigated through orthogonal experiments to determine their effects on the sludge disintegration, sludge concentration and sludge morphology of sewage sludge. The experimental results showed that the significance of the four factors on sludge characteristics was in the order of pH > temperature > treatment time > sludge concentration. Additionally, the optimal conditions of the four factors for the release of soluble chemical oxygen demand (SCOD) of unit sludge and decrease of sludge concentration were as follows: 36.55 g x L(-1), pH 12.45, 175 degrees C and 60 min. While the optimal conditions for the decrease of particle size and fractal dimension were 36.55 g x L(-1), pH 12.5, 175 degrees C and 45 min.

  6. Galvanic sludge metals recovery by pyrometallurgical and hydrometallurgical treatment.

    PubMed

    Rossini, Gustavo; Bernardes, Andréa Moura

    2006-04-17

    This paper reports a study, on laboratory scale, of sulphating roasting to perform a treatment for a selective recovery of valuable metals from galvanic sludge. The target metals were copper, zinc and nickel and the sulphating agent used was pyrite, from coal wastes. The particularity of this treatment is the use of two hazardous wastes as raw material. They are generated in large quantities at coal extraction sites (coal wastes) and at plating shops (galvanic sludge). The wastes were characterized by X-ray fluorescence (XRF), particle size distribution and water contents. The chemical characterization showed sludges with high copper concentration, with more than 14% (dry base). In the roasting step, the galvanic sludge was mixed with pyritic waste and the parameters evaluated were galvanic sludge/pyrite ratio, roasting temperature and roasting time. After roasting, the product of reaction was leached with water in room temperature for 15 min. Considering that other studies have already demonstrated that the pyrometallurgical step determines the process efficiency, this paper only reports the influence of pyrometallurgical parameters. Hydrometallurgical processes will be better evaluated in further studies. The conditions that best reflect a compromise between the valuable metal recover and the economical viability of the process were achieved for 1:0.4 galvanic sludge/pyrite ratio, 90 min of roasting time and 550 degrees C of roasting temperature. These conditions lead to a recovery of 60% zinc, 43% nickel and 50% copper.

  7. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  8. Heat Treatment. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Filer, Herb; Broste, Dale

    This lesson was developed for a course in sludge treatment and disposal. The lesson describes the Porteous heat treatment method of sludge conditioning and compares that system to the Zimpro wet air oxidation process. The theory of heat treatment, system of components and functions, and concepts of operation are addressed in the lesson. The…

  9. Anammox biofilm in activated sludge swine wastewater treatment plants.

    PubMed

    Suto, Ryu; Ishimoto, Chikako; Chikyu, Mikio; Aihara, Yoshito; Matsumoto, Toshimi; Uenishi, Hirohide; Yasuda, Tomoko; Fukumoto, Yasuyuki; Waki, Miyoko

    2017-01-01

    We investigated anammox with a focus on biofilm in 10 wastewater treatment plants (WWTPs) that use activated sludge treatment of swine wastewater. In three plants, we found red biofilms in aeration tanks or final sedimentation tanks. The biofilm had higher anammox 16S rRNA gene copy numbers (up to 1.35 × 10(12) copies/g-VSS) and higher anammox activity (up to 295 μmoL/g-ignition loss/h) than suspended solids in the same tank. Pyrosequencing analysis revealed that Planctomycetes accounted for up to 17.7% of total reads in the biofilm. Most of them were related to Candidatus Brocadia or Ca. Jettenia. The highest copy number and the highest proportion of Planctomycetes were comparable to those of enriched anammox sludge. Thus, swine WWTPs that use activated sludge treatment can fortuitously acquire anammox biofilm. Thus, concentrated anammox can be detected by focusing on red biofilm.

  10. Solar-thermic sewage sludge treatment in extreme alpine environments.

    PubMed

    Becker, W; Schoen, M A; Wett, B

    2007-01-01

    In the framework of a program for environmental protection conducted by the German mountaineers' club (DAV) problems emerging from residual solids accumulating in on-site wastewater treatment plants of mountain refuges were investigated. To handle these problems in an ecologically and economically reasonable way two devices for solar-supported treatment of sludge and bio-solids have been developed. These units support gravity-filtration and evaporation of liquid sludge as well as thermal acceleration of composting processes. Two solar sludge dryers were installed and operated without external energy supply at alpine refuges treating primary and secondary sludge, respectively. Batch-filling during the season could increase load capacity and a total solids concentration of up to 40% could be achieved before discharge at the beginning of the next season. The promising results from the solar sludge dryer encouraged for the development of a solar composter. The period of temperature levels suitable for composting biosolids in mountain areas can be extended considerably by application of this technology--measured temperature distribution indicated no freezing at all.

  11. Characterization of water treatment sludge and its reuse as coagulant.

    PubMed

    Ahmad, Tarique; Ahmad, Kafeel; Ahad, Abdul; Alam, Mehtab

    2016-11-01

    Coagulation-flocculation process results in the generation of large volume of waste or residue, known as water treatment sludge (WTS), in the purification of surface water for potable supplies. Sustainable management of the inevitable waste requires careful attention from the plant operators and sludge managers. In this study, WTS produced with the optimum alum dose of 30 ml/L at the laboratory scale has been treated with sulphuric acid to bring forth a product known as sludge reagent product (SRP). The performance of SRP is evaluated for its efficiency in removing the colloidal suspensions from the Yamuna river water over wide pH range of 2-13. 1% sludge acidified with sulphuric acid of normality 2.5 at the rate of 0.05 ml/ml sludge has been observed as the optimum condition for preparing SRP from WTS. The percentage turbidity removal is greater at higher pH value and increases with increasing the dosage of SRP. The optimum SRP dosage of 8 ml/L in the pH range of 6-8 performed well in removing the colloidal suspension and other impurities from the Yamuna water. The quality of treated water met the prescribed standards for most of the quality parameters. Thus, SRP has the potential to substitute the conventional coagulants partially or completely in the water treatment process, depending on the quality needed at the users end.

  12. Phytoremediation of oilfield sludge after prepared bed bioremediation treatment.

    PubMed

    Liu, Wuxing; Luo, Yongming; Teng, Ying; Li, Zhen'gao

    2010-03-01

    A field-scale experiment was carried out to compare the effectiveness of five plant species in the remediation of oily sludge. Alfalfa, tall fescue, and soybean substantially increased the removal rate of oil and grease (O&G) after 120 days of remediation. Of these, soybean treatment showed the highest removal rate of 34.2% compared with only 13.7% in the unplanted control plot. In addition to assisting with phytoremediation, soybean can also be used for energy production, for example in the production of biodiesel. Furthermore, microbial counts and community level physiological profiling using Biolog sole carbon source utilization tests were used to investigate the effect of plants on the microbial community of oily sludge. Plants selectively increased microbial counts in the rhizosphere and O&G concentrations of the sludge were negatively correlated with counts of TPH (total petroleum hydrocarbon) degraders. The acute biotoxicity of the sludge was also tested by the bacterial luminescence method and alfalfa treatments decreased the biological toxicity of the sludge compared with the unplanted control.

  13. Critical review of the influences of nanoparticles on biological wastewater treatment and sludge digestion.

    PubMed

    Wang, Dongbo; Chen, Yinguang

    2016-10-01

    Nanoparticles (NPs), with at least one dimension less than 100 nm, are substantially employed in consumer and industrial products due to their specific physical and chemical properties. The wide uses of engineered NPs inevitably cause their release into the environment, especially wastewater treatment plants. Therefore, it is essential to systematically assess their potential impact on biological wastewater treatment and subsequent sewage sludge digestion. This review aims to provide such support. First, this paper reviews the recent advances on the analytical developments and nano-bio interface of NPs in wastewater and sewage sludge treatment. The effects of NPs on biological wastewater treatment and sewage sludge digestion and related mechanisms are discussed in detail. Finally, the key questions that need to be answered in the future are pointed out, which include on-line revelation of the changes of NPs in sewage and sludge environments, in situ assessment of the variations of microorganisms involved in these biological systems after they are exposed to NPs. Differentiation of the contribution of individual toxicity mechanisms to these systems, and the identification of under what conditions the nanoparticle-induced toxicity will be increased or decreased are also considered.

  14. Integrated application of upflow anaerobic sludge blanket reactor for the treatment of wastewaters.

    PubMed

    Latif, Muhammad Asif; Ghufran, Rumana; Wahid, Zularisam Abdul; Ahmad, Anwar

    2011-10-15

    The UASB process among other treatment methods has been recognized as a core method of an advanced technology for environmental protection. This paper highlights the treatment of seven types of wastewaters i.e. palm oil mill effluent (POME), distillery wastewater, slaughterhouse wastewater, piggery wastewater, dairy wastewater, fishery wastewater and municipal wastewater (black and gray) by UASB process. The purpose of this study is to explore the pollution load of these wastewaters and their treatment potential use in upflow anaerobic sludge blanket process. The general characterization of wastewater, treatment in UASB reactor with operational parameters and reactor performance in terms of COD removal and biogas production are thoroughly discussed in the paper. The concrete data illustrates the reactor configuration, thus giving maximum awareness about upflow anaerobic sludge blanket reactor for further research. The future aspects for research needs are also outlined.

  15. Toluene in sewage and sludge in wastewater treatment plants.

    PubMed

    Mrowiec, Bozena

    2014-01-01

    Toluene is a compound that often occurs in municipal wastewater ranging from detectable levels up to 237 μg/L. Before the year 2000, the presence of the aromatic hydrocarbons was assigned only to external sources. The Enhanced Biological Nutrients Removal Processes (EBNRP) work according to many different schemes and technologies. For high-efficiency biological denitrification and dephosphatation processes, the presence of volatile fatty acids (VFAs) in sewage is required. VFAs are the main product of organic matter hydrolysis from sewage sludge. However, no attention has been given to other products of the process. It has been found that in parallel to VFA production, toluene formation occurred. The formation of toluene in municipal anaerobic sludge digestion processes was investigated. Experiments were performed on a laboratory scale using sludge from primary and secondary settling tanks of municipal treatment plants. The concentration of toluene in the digested sludge from primary settling tanks was found to be about 42,000 μg/L. The digested sludge supernatant liquor returned to the biological dephosphatation and denitrification processes for sewage enrichment can contain up to 16,500 μg/L of toluene.

  16. Evaluation of energy consumption during aerobic sewage sludge treatment in dairy wastewater treatment plant.

    PubMed

    Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł

    2017-02-01

    The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm(-3) with the average value at 1.17 kWhm(-3). The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs.

  17. Treatment of sewage sludge generated in municipal wastewater treatment plants.

    PubMed

    Tavares, Célia R G; Benatti, Cláudia T; Dias Filho, Benedito P

    2002-01-01

    This study was designed to evaluate the performance of a cylindrical anaerobic digester in treating secondary sewage sludge. A series of three independent batch experiments was performed for a total operation time of 60 d. The system of anaerobic digestion showed stability conditions, with no noticeable scum or foaming problems. The chemical oxygen demand reduction reached 29,21, and 45% in sludge and 95,85, and 82% in supernatant for the three experiments, respectively. Total coliform bacteria levels in the digester ranged from 10(4) to 10(5) in influent sludge and from 10(4) to 10(3) in effluent sludge, with an average reduction of 90%. Fecal coliforms of the order of 10(4) were enumerated in influent sludge and those of the order of 10(0) were enumerated in effluent sludge, with an average reduction of 99.9%. The studied system had satisfactory results, showing that both organic matter and indicator bacteria levels substantially decrease when the sludge is submitted to anaerobic digestion.

  18. Energy recovery from thermal treatment of dewatered sludge in wastewater treatment plants.

    PubMed

    Yang, Qingfeng; Dussan, Karla; Monaghan, Rory F D; Zhan, Xinmin

    Sewage sludge is a by-product generated from municipal wastewater treatment (WWT) processes. This study examines the conversion of sludge via energy recovery from gasification/combustion for thermal treatment of dewatered sludge. The present analysis is based on a chemical equilibrium model of thermal conversion of previously dewatered sludge with moisture content of 60-80%. Prior to combustion/gasification, sludge is dried to a moisture content of 25-55% by two processes: (1) heat recovered from syngas/flue gas cooling and (2) heat recovered from syngas combustion. The electricity recovered from the combined heat and power process can be reused in syngas cleaning and in the WWT plant. Gas temperature, total heat and electricity recoverable are evaluated using the model. Results show that generation of electricity from dewatered sludge with low moisture content (≤ 70%) is feasible within a self-sufficient sludge treatment process. Optimal conditions for gasification correspond to an equivalence ratio of 2.3 and dried sludge moisture content of 25%. Net electricity generated from syngas combustion can account for 0.071 kWh/m(3) of wastewater treated, which is up to 25.4-28.4% of the WWT plant's total energy consumption.

  19. Advances in Alcoholism Treatment

    PubMed Central

    Huebner, Robert B.; Kantor, Lori Wolfgang

    2011-01-01

    Researchers are working on numerous and varied approaches to improving the accessibility, quality, effectiveness, and cost-effectiveness of treatment for alcohol use disorders (AUDs). This overview article summarizes the approaches reviewed in this issue, including potential future developments for alcoholism treatment, such as medications development, behavioral therapy, advances in technology that are being used to improve treatment, integrated care of patients with AUDs and co-occurring disorders, the role of 12-step programs in the broader realm of treatment, treating patients with recurring and chronic alcohol dependence, strategies to close the gap between treatment need and treatment utilization, and how changes in the health care system may affect the delivery of treatment. This research will not only reveal new medications and behavioral therapies but also will contribute to new ways of approaching current treatment problems. PMID:23580014

  20. Up-to-date modification of the anaerobic sludge digestion process introducing a separate sludge digestion mode.

    PubMed

    Sato, K; Ochi, S; Mizuochi, M

    2001-01-01

    Sewage treatment plants in Japan are subjected to advanced treatment to remove nutrients and hence control eutrophication problems in lakes and bays. This paper discusses the advantages and disadvantages of the separate digestion treatment mode for sludge generated from advanced wastewater treatment. In the separate digestion only primary sludge is digested and the excess activated sludge is directly dewatered. Separate digestion can reduce the return load of nutrients to approximately one third, and has major potential for the beneficial use of sludge.

  1. Fermentation and chemical treatment of pulp and paper mill sludge

    DOEpatents

    Lee, Yoon Y; Wang, Wei; Kang, Li

    2014-12-02

    A method of chemically treating partially de-ashed pulp and/or paper mill sludge to obtain products of value comprising taking a sample of primary sludge from a Kraft paper mill process, partially de-ashing the primary sludge by physical means, and further treating the primary sludge to obtain the products of value, including further treating the resulting sludge and using the resulting sludge as a substrate to produce cellulase in an efficient manner using the resulting sludge as the only carbon source and mixtures of inorganic salts as the primary nitrogen source, and including further treating the resulting sludge and using the resulting sludge to produce ethanol.

  2. Preliminary Study of Thermal Treatment of Coke Wastewater Sludge Using Plasma Torch

    NASA Astrophysics Data System (ADS)

    Li, Mingshu; Li, Shengli; Sun, Demao; Liu, Xin; Feng, Qiubao

    2016-10-01

    Thermal plasma was applied for the treatment of coke wastewater sludge derived from the steel industry in order to investigate the feasibility of the safe treatment and energy recovery of the sludge. A 30 kW plasma torch system was applied to study the vitrification and gas production of coke wastewater sludge. Toxicity leaching results indicated that the sludge treated via the thermal plasma process converted into a vitrified slag which resisted the leaching of heavy metals. CO2 was utilized as working gas to study the production and heat energy of the syngas. The heating value of the gas products by thermal plasma achieved 8.43 kJ/L, indicating the further utilization of the gas products. Considering the utilization of the syngas and recovery heat from the gas products, the estimated treatment cost of coke wastewater sludge via plasma torch was about 0.98 CNY/kg sludge in the experiment. By preliminary economic analysis, the dehydration cost takes an important part of the total sludge treatment cost. The treatment cost of the coke wastewater sludge with 50 wt.% moisture was calculated to be about 1.45 CNY/kg sludge dry basis. The treatment cost of the coke wastewater sludge could be effectively controlled by decreasing the water content of the sludge. These findings suggest that an economic dewatering pretreatment method could be combined to cut the total treatment cost in an actual treatment process.

  3. Method for lime stabilization of wastewater treatment plant sludges

    SciTech Connect

    Wurtz, W.O.

    1981-12-22

    A method for the lime stabilization of wastewater sludge, includes the steps of dewatering sludge so as to produce a sludge cake containing from about 10 to 60% by weight of dry solids and rapidly and intimately mixing and reacting the sludge cake with calcium oxide so as to produce stabilized sludge pellets. An apparatus for performing the process is also provided.

  4. Sludge Treatment and Extraction Technology Development: Results of FY 1993 studies

    SciTech Connect

    Lumetta, G.J.; Wagner, M.J.; Barrington, R.J.; Rapko, B.M.; Carlson, C.D.

    1994-03-01

    This report describes experimental results from work conducted in FY 1993 under the Sludge Treatment and Extraction Technology Development Task of the Tank Waste Remediation System (TWRS) Pretreatment Technology Development Project at Pacific Northwest Laboratory (PNL). Experiments were conducted in the following six general areas: (1) sludge washing, (2) sludge leaching, (3) sludge dissolution, (4) actinide separation by solvent extraction and extraction chromatography, (5) Sr separation by solvent extraction, and (6) extraction of Cs from acidic solution.

  5. Use of activated sludge biomass as an agent for advanced primary separation.

    PubMed

    Araneda, Michael; Pavez, Javier; Luza, Benjamín; Jeison, David

    2017-05-01

    Conventional primary settling is a physical process of solid-liquid separation, normally presenting low removal efficiencies. Improvement of this separation process would result in energetic advantages: lower aeration requirements and higher biogas production form primary and secondary sludges. Secondary sludge has been proposed as a potential agent promoting an increase in primary separation efficiency. Few processes have been proposed, based on the cultivation of sludge under special conditions. However, one can speculate that regular sludge may have a similar effect. The aim of this research was to study that possibility. Sludges from different activated sludge reactors were tested. Results showed that COD removals were up to 55%, 2 times higher than that for simple settling. Under that condition, COD balances showed that aeration requirements would reduce 40%, and biogas production from primary and secondary sludges would increase 50%. It is inferred then that the application of activated sludge as an external agent represents an interesting alternative that have the potential to significantly improve energetic efficiency of sewage treatment plants.

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

    PubMed

    Stoica, Alina; Sandberg, Maria; Holby, Ola

    2009-07-01

    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.

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

    SciTech Connect

    Not Available

    1984-05-01

    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.

  8. Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogen production.

    PubMed

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

    2015-02-01

    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.

  9. Recent advances and future perspectives of nanosized zero- valent iron for extraction of heavy elements from metallurgical sludges

    NASA Astrophysics Data System (ADS)

    Mikhailov, I. Yu; Levina, V. V.; Kolesnikov, E. A.; Chuprunov, K. O.; Gusev, A. A.; Godymchuk, A. Yu; Kuznetsov, D. V.

    2016-01-01

    Advanced oxidation processes with nanosized zero-valent iron have presented great potential in wastewater treatment technology and now experience both increasing popularity and reliable technical improvements. Besides wastewater treatment, there is another promising application for an emerging technology of iron nanoparticles - as Fenton-like catalyst for extraction of valuable elements from poor and secondary raw materials such as metallurgical sludges. In present research, we carried out a set of experiments with emphasis on the physicochemical mechanisms and their relationship to the performance. In particular, we examined complex acidic - hydrogen peroxide leaching of zinc from blast furnace sludge with nanosized zero-valent iron as Fenton-like catalyst. Results of the experiments showed promising potential for subsequent application in extraction of heavy and rare-earth elements.

  10. Arsenic leachability and speciation in cement immobilized water treatment sludge.

    PubMed

    Jing, Chuanyong; Liu, Suqin; Meng, Xiaoguang

    2005-06-01

    Arsenic leachability and speciation in cement immobilized water treatment sludge were investigated with leaching tests and X-ray absorption near edge structure (XANES) spectroscopy. The As leachability in the sludge determined with the toxicity characteristic leaching procedure (TCLP) and the waste extraction test (WET) was 283 and 7490 microgl(-1), respectively. Extractions with a lower liquid to solid ratio, under anaerobic conditions, and using citric acid buffer solution dramatically increased the leachate As concentration. XANES results showed that the As(III) composition was reduced from 51.1% of the total As content in the sludge to 16.3% in the cement treated sample with 28 days of cure. When the cement treated sample was cured for two years, the As(III) composition was decreased to 7.4%. The cement treatment reduced the As leachability. The leachate As(III) and total As concentrations were of the same order of magnitude in the samples cured for 28 days as for 2yr. However, consistently lower concentrations were detected in samples with longer cure time. The results of this study improve our understanding of arsenic speciation and leachability in the cement matrix after long cure times.

  11. Wastewater treatment sludge as a raw material for the production of Bacillus thuringiensis based biopesticides.

    PubMed

    Montiel, M D; Tyagi, R D; Valero, J R

    2001-11-01

    Seven wastewater sludges of different origins and types were used as an alternate culture medium for producing Bacillus thuringiensis variety kurstaki HD-1. The sludge samples were used under three different preparations: without pre-treatment, with acid treatment (hydrolysed sludge) and the supernatant obtained after centrifugation of the hydrolysed sludge. The sludge composition varied widely with origin and the type of sludge. Growth and sporulation were evaluated by the total viable cell count and spore count of the preparations. Growth, sporulation and endotoxin production were affected by the sludge origin. Hydrolysed sludge gave the highest viable cell and spore counts while the liquid phase (supernatant) gave the lowest. Non-hydrolysed primary sludge from Valcartier was unable to sustain bacterial growth because of its low pH. Bioassays were conducted against larvae of spruce budworm to evaluate entomotoxic potential of the preparations obtained. In general, sludge hydrolysis increased the entomotoxicity yields. Similar entomotoxicity was observed in Black Lake secondary sludge (4100 IU/microL) as that obtained in the reference soya medium (3800 IU/microL). The use of the sludge supernatant (liquid phase) was not recommended due to the low entomotoxic potential obtained.

  12. Greenhouse gas emissions from sludge treatment reed beds.

    PubMed

    Cui, Yubo; Zhang, Shunli; Chen, Zhaobo; Chen, Rui; Deng, Xinnan

    2015-01-01

    Sludge treatment reed bed systems (STRBs) are considered as an alternative technology for surplus sludge treatment. Organic matter is decomposed by various microbial reactions, resulting in gases such as CO₂and CH₄emitting into the atmosphere. The aim of this study is to investigate gas emission from STRBs. The static transparent chamber was adopted to measure gas emission; it allows sunlight to enter and plants to photosynthesise. The comparison of total solids and volatile solids showed STRBs have a higher efficiency in dewatering and mineralization than a conventional unplanted sludge drying bed (USDB). The CO₂emission ranged from 28.68 to 100.42 g CO₂m⁻² d(-1) in USDB, from 16.48 to 65.18 g CO₂m⁻² d⁻¹ in STRBs; CH₄emission ranged from 0.26 to 0.99 g CH₄ m⁻² d⁻¹ in USDB, from 0.43 to 1.95 g CH₄m⁻² d⁻¹ in STRBs. Both gas fluxes decreased towards the end of vegetation and reached the highest rates during the hot and dry summer. After the system was loaded by sludge, the fluxes of CO₂and CH₄significantly decreased in the USDB, whereas they increased in STRBs. In terms of CO₂equivalent, the global warming potential of CH₄was 13.13 g CO₂eq m⁻² d⁻¹ and 15.02 g CO₂eq m⁻² d⁻¹ in USDB and STRBs, respectively.

  13. Quantification of greenhouse gas emissions from sludge treatment wetlands.

    PubMed

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

    2012-04-15

    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.

  14. Emissions of CO2 and CH4 from sludge treatment reed beds depend on system management and sludge loading.

    PubMed

    Olsson, Linda; Dam Larsen, Julie; Ye, Siyuan; Brix, Hans

    2014-08-01

    Sludge treatment reed beds (STRB) are considered as eco-friendly and sustainable alternatives to conventional sludge treatment methods, although little is known about greenhouse gas emissions from such systems. We measured CO2 and CH4 emissions and substrate characteristics in a STRB, an occasionally loaded sludge depot (SD) and a natural reed wetland (NW). The aim was to compare (i) emissions among the sites in relation to substrate characteristics and (ii) emissions before and after sludge loading in the STRB. The STRB emitted twice as much CO2 (1200 mg m(-2) h(-1)) as the SD, whereas the SD emitted four times more CH4 (2 mg m(-2) h(-1)) than the STRB. The NW had the lowest emissions of both gases. The differences in gas emissions among the sites were primarily explained by differences in the availability of oxygen in the substrate. As a consequence of overloading and poor management, the SD had no vegetation and a poor dewatering capacity, which resulted in anaerobic conditions favoring CH4 emission. In contrast, the well-managed STRB had more aerobic conditions in the sludge residue resulting in low CH4 emission rates. We conclude that well-designed and well-managed STRBs have a low climate impact relative to conventional treatment alternatives, but that overloading and poor sludge management enhances the emissions of CH4.

  15. Advanced two-phase digestion of sewage sludge

    SciTech Connect

    Ghosh, S.

    1984-01-01

    This paper describes the development and operating results of a novel configuration of the two-phase digestion concept. The two-phase system, comprises two custom-designed upflow digesters, which were operated in tandem to optimize the liquefying-acidification and acetogenesis-methanation reactions. The results are based on system operation for more than one year with a high-metal-content sewage sludge. During the operating period, the system exhibited an increasing methane yield at hydraulic retention times (HRT) of less than 6 days. With continuing culture enrichment and improvements in reactor design, the methane yield increased from 5 to 6.8 SCF/lb VS added, and then to 7.7 SCF/lb VS added. This methane yield was about 80% of the theoretical methane yield achievable with this sewage sludge--and the highest methane yield reported for sludge at this HRT. Operation of the novel process configuration was very stable and superior to that of conventional single-stage digestion in terms of methane yield, gas generation rate, and net energy production. About 75 weight percent of the organic solids was gasified; this could be the maximum attainable feed conversion efficiency for sludge, considering that between 75% and 80% of this feed is normally biodegradable. 3 references, 7 tables.

  16. Activated Sludge. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Boe, Owen K.; Klopping, Paul H.

    This student manual contains the textual material for a seven-lesson unit on activated sludge. Topic areas addressed in the lessons include: (1) activated sludge concepts and components (including aeration tanks, aeration systems, clarifiers, and sludge pumping systems); (2) activated sludge variations and modes; (3) biological nature of activated…

  17. Extending the use of dewatered alum sludge as a P-trapping material in effluent purification: Study on two separate water treatment sludges.

    PubMed

    Zhao, Y Q; Yang, Y

    2010-08-01

    The generation of alum sludge from drinking water purification process remains inevitable when aluminium sulphate is used as primary coagulant for raw water coagulation. Sustainable managing such the sludge becomes an increasing concern in water industry. Its beneficial reuse is therefore highly desirable and has attracted considerable research efforts. In view of the novel development of alum sludge as a value-added raw material for beneficial reuse for wastewater treatment, this study examined the maximum phosphorus-adsorption capacity of two dewatered alum sludges sampled from two largest water treatment works in Dublin, Ireland. The objective lies in clarifying the change of alum sludge characteristics and its P-adsorption capacity over the location of the alum sludge produced and the raw water being treated. Experiments have demonstrated that the two alum sludges have the similar P adsorption capacity (14.3 mg P/g sludge for Ballymore-Eustace sludge and 13.1 mg P/g sludge for Leixlip sludge at pH 7.0). However, the study supports that alum sludge beneficial reuse as a low cost adsorbent for P immobilization should study its P-adsorption capacity before any decision of large application is made since the raw water quality will affect the sludge characteristics and therefore influence its adsorption ability.

  18. Primary Treatment and Sludge Digestion Workshop.

    ERIC Educational Resources Information Center

    Ontario Ministry of the Environment, Toronto.

    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;…

  19. New developments in microwave treatment of steel mill sludges

    SciTech Connect

    Goodwill, J.E.; Schmitt, R.J.; Purta, D.A.

    1996-02-01

    Steel mills in the US generate approximately 1 million tons of sludge annually. This is mainly a residue of cooling water, lubricating oils, and metallic fines from hot strip rolling mills and other operations. Currently, the separation of sludge from the liquid requires large settling tanks, takes several hours of time and produces a residue that must be disposed of at high cost. The EPRI Center for Materials Production, sponsored by the Electric Power Research Institute (EPRI), has supported development of a microwave-based treatment system. This new process, developed by Carnegie Mellon Research Institute, and patented by EPRI is 30 times faster, requires 90% less space and eliminates land-filling by producing materials of value. Electricity usage is only 0.5 kwhr/gal. A review by the American Iron and Steel Institute Waste Recycle Technology Task Force concluded that further work on the microwave technology was justified. Subsequently, additional work was undertaken toward optimizing the process for treating metallic waste sludges containing lime and polymers. This effort, cofunded by EPRI and AISI, was successfully concluded in late 1994. EPRI/CMP is proceeding to license and commercialize this technology, and to continue research to improve efficiency. A follow-on project is now being organized by CMP to confirm long term recyclability of the oil-release agent and to conduct a large scale (25-ton sample) test of the process.

  20. Two strategies for phosphorus removal from reject water of municipal wastewater treatment plant using alum sludge.

    PubMed

    Yang, Y; Zhao, Y Q; Babatunde, A O; Kearney, P

    2009-01-01

    In view of the well recognized need of reject water treatment in MWWTP (municipal wastewater treatment plant), this paper outlines two strategies for P removal from reject water using alum sludge, which is produced as by-product in drinking water treatment plant when aluminium sulphate is used for flocculating raw waters. One strategy is the use of the alum sludge in liquid form for co-conditioning and dewatering with the anaerobically digested activated sludge in MWWTP. The other strategy involves the use of the dewatered alum sludge cakes in a fixed bed for P immobilization from the reject water that refers to the mixture of the supernatant of the sludge thickening process and the supernatant of the anaerobically digested sludge. Experimental trials have demonstrated that the alum sludge can efficiently reduce P level in reject water. The co-conditioning strategy could reduce P from 597-675 mg P/L to 0.14-3.20 mg P/L in the supernatant of the sewage sludge while the organic polymer dosage for the conditioning of the mixed sludges would also be significantly reduced. The second strategy of reject water filtration with alum sludge bed has shown a good performance of P reduction. The alum sludge has P-adsorption capacity of 31 mg-P/g-sludge, which was tested under filtration velocity of 1.0 m/h. The two strategies highlight the beneficial utilization of alum sludge in wastewater treatment process in MWWTP, thus converting the alum sludge as a useful material, rather than a waste for landfill.

  1. A review of wet air oxidation and Thermal Hydrolysis technologies in sludge treatment.

    PubMed

    Hii, Kevin; Baroutian, Saeid; Parthasarathy, Raj; Gapes, Daniel J; Eshtiaghi, Nicky

    2014-03-01

    With rapid world population growth and strict environmental regulations, increasingly large volumes of sludge are being produced in today's wastewater treatment plants (WWTP) with limited disposal routes. Sludge treatment has become an essential process in WWTP, representing 50% of operational costs. Sludge destruction and resource recovery technologies are therefore of great ongoing interest. Hydrothermal processing uses unique characteristics of water at elevated temperatures and pressures to deconstruct organic and inorganic components of sludge. It can be broadly categorized into wet oxidation (oxidative) and thermal hydrolysis (non-oxidative). While wet air oxidation (WAO) can be used for the final sludge destruction and also potentially producing industrially useful by-products such as acetic acid, thermal hydrolysis (TH) is mainly used as a pre-treatment method to improve the efficiency of anaerobic digestion. This paper reviews current hydrothermal technologies, roles of wet air oxidation and thermal hydrolysis in sludge treatment, and challenges faced by these technologies.

  2. Impact of aerobic stabilization on the characteristics of treatment sludge in the leather tanning industry.

    PubMed

    Cokgor, Emine Ubay; Aydinli, Ebru; Tas, Didem Okutman; Zengin, Gulsum Emel; Orhon, Derin

    2014-01-01

    The efficiency of aerobic stabilization on the treatment sludge generated from the leather industry was investigated to meet the expected characteristics and conditions of sludge prior to landfill. The sludge types subjected to aerobic stabilization were chemical treatment sludge, biological excess sludge, and the mixture of both chemical and biological sludges. At the end of 23 days of stabilization, suspended solids, volatile suspended solids and total organic carbon removal efficiencies were determined as 17%, 19% and 23% for biological sludge 31%, 35% and 54% for chemical sludge, and 32%, 34% and 63% for the mixture of both chemical and biological sludges, respectively. Model simulations of the respirometric oxygen uptake rate measurements showed that the ratio of active biomass remained the same at the end of the stabilization for all the sludge samples. Although mixing the chemical and biological sludges resulted in a relatively effective organic carbon and solids removal, the level of stabilization achieved remained clearly below the required level of organic carbon content for landfill. These findings indicate the potential risk of setting numerical restrictions without referring to proper scientific support.

  3. How does the entering of copper nanoparticles into biological wastewater treatment system affect sludge treatment for VFA production.

    PubMed

    Chen, Hong; Chen, Yinguang; Zheng, Xiong; Li, Xiang; Luo, Jingyang

    2014-10-15

    Usually the studies regarding the effect of engineered nanoparticles (NPs), which are released to wastewater treatment plant, on sludge anaerobic treatment in the literature have been conducted by directly adding NPs to sludge treatment system. Actually, NPs must enter into the wastewater treatment facility from influent before sludge being treated. Thus, the documented results can not reflect the real situations. During sludge anaerobic treatment for producing volatile fatty acids (VFA, the preferred carbon source for wastewater biological nutrient removal), it was found in this study that the entering of CuNPs to biological wastewater treatment system had no significant effect on sludge-derived VFA generation, while direct addition of CuNPs to sludge fermentation reactor caused a much lower VFA production, when compared to the control test. Further investigation revealed that the entering of CuNPs into wastewater biological treatment system improved sludge solubilization due to the decline of sludge particle size and the increase of sludge microorganism cells breakage. In addition, there was no obvious influence on hydrolysis, while significant inhibition was observed on acidification, resulting in the final VFA production similar to the control. When CuNPs were directly added to the fermentation system, the solubilization was little influenced, however the hydrolysis and acidification were seriously inhibited, causing the ultimate VFA generation decreased. Therefore, selecting proper method close to the real situation is vital to accurately assess the toxicity of nanoparticles on sludge anaerobic fermentation.

  4. Current state of sludge production, management, treatment and disposal in China.

    PubMed

    Yang, Guang; Zhang, Guangming; Wang, Hongchen

    2015-07-01

    Large amount of sludge has been a great trouble and raised significant concerns in China. This paper reviewed the current situation of sludge production, management, treatment and disposal in China. Total sludge production in China had an average annual growth of 13% from 2007 to 2013, and 6.25 million tons dry solids was produced in 2013. Per Capita sludge production in China is lower than that in developed countries. However, sludge management is poor in China. Administrative agents of sludge are not in accordance with each other. Laws and regulations of sludge management are incomplete and sometimes unrealistic. As to sludge treatment and disposal, many technical routes have been applied in China. Thickening, conditioning, and dewatering are three most used treatment methods, while application ratios of stabilization and drying are low in China. More than 80% of sludge is disposed by improper dumping in China. Regarding proper disposal, sanitary landfill is the commonest, followed by land application, incineration and building materials. According to the overall situation of China, "thickening-anaerobic digestion-dewatering-land application" is the priority technical route of sludge treatment and disposal. Good changes, current challenges and future perspectives of this technical route in China were analyzed and discussed in details.

  5. Predicting the drying properties of sludge based on hydrothermal treatment under subcritical conditions.

    PubMed

    Mäkelä, Mikko; Fraikin, Laurent; Léonard, Angélique; Benavente, Verónica; Fullana, Andrés

    2016-03-15

    The effects of hydrothermal treatment on the drying properties of sludge were determined. Sludge was hydrothermally treated at 180-260 °C for 0.5-5 h using NaOH and HCl as additives to influence reaction conditions. Untreated sludge and attained hydrochar samples were then dried under identical conditions with a laboratory microdryer and an X-ray microtomograph was used to follow changes in sample dimensions. The effective moisture diffusivities of sludge and hydrochar samples were determined and the effect of process conditions on respective mean diffusivities evaluated using multiple linear regression. Based on the results the drying time of untreated sludge decreased from approximately 80 min to 37-59 min for sludge hydrochar. Drying of untreated sludge was governed by the falling rate period where drying flux decreased continuously as a function of sludge moisture content due to heat and mass transfer limitations and sample shrinkage. Hydrothermal treatment increased the drying flux of sludge hydrochar and decreased the effect of internal heat and mass transfer limitations and sample shrinkage especially at higher treatment temperatures. The determined effective moisture diffusivities of sludge and hydrochar increased as a function of decreasing moisture content and the mean diffusivity of untreated sludge (8.56·10(-9) m(2) s(-1)) and sludge hydrochar (12.7-27.5·10(-9) m(2) s(-1)) were found statistically different. The attained regression model indicated that treatment temperature governed the mean diffusivity of hydrochar, as the effects of NaOH and HCl were statistically insignificant. The attained results enabled prediction of sludge drying properties through mean moisture diffusivity based on hydrothermal treatment conditions.

  6. Bacillus licheniformis proteases as high value added products from fermentation of wastewater sludge: pre-treatment of sludge to increase the performance of the process.

    PubMed

    Drouin, M; Lai, C K; Tyagi, R D; Surampalli, R Y

    2008-01-01

    Wastewater sludge is a complex raw material that can support growth and protease production by Bacillus licheniformis. In this study, sludge was treated by different thermo-alkaline pre-treatment methods and subjected to Bacillus licheniformis fermentation in bench scale fermentors under controlled conditions. Thermo-alkaline treatment was found to be an effective pre-treatment process in order to enhance the proteolytic activity. Among the different pre-treated sludges tested, a mixture of raw and hydrolysed sludge caused an increase of 15% in the protease activity, as compared to the untreated sludge. The benefit of hydrolysis has been attributed to a better oxygen transfer due to decrease in media viscosity and to an increase in nutrient availability. Foam formation was a major concern during fermentation with hydrolysed sludge. The studies showed that addition of a chemical anti-foaming agent (polypropylene glycol) during fermentation to control foam could negatively influence the protease production by increasing the viscosity of sludge.

  7. Ubiquity of activated sludge ferricyanide-mediated BOD methods: a comparison of sludge seeds across wastewater treatment plants.

    PubMed

    Jordan, Mark A; Welsh, David T; Teasdale, Peter R

    2014-07-01

    Many studies have described alternatives to the BOD5 standard method, with substantial decreases in incubation time observed. However, most of these have not maintained the features that make the BOD5 assay so relevant - a high level of substrate bio-oxidation and use of wastewater treatment plant (WWTP) sludge as the biocatalyst. Two recently described ferricyanide-mediated (FM)-BOD assays, one for trade wastes and one for WWTP influents and treated effluents, satisfy these criteria and were investigated further here for their suitability for use with diverse biocatalysts. Both FM-BOD assays responded proportionately to increasing substrate concentration with sludges from 11 different WWTPs and temporally (months to years) using sludges from a single WWTP, confirming the broad applicability of both assays. Sludges from four WWTPs were selected as biocatalysts for each FM-BOD assay to compare FM-BOD equivalent values with BOD5 (three different sludge seeds) measurements for 12 real wastewater samples (six per assay). Strong and significant relationships were established for both FM-BOD assays. This study has demonstrated that sludge sourced from many WWTPs may be used as the biocatalyst in either FM-BOD assay, as it is in the BOD5 assay. The industry potential of these findings is substantial given the widespread use of the BOD5 assay, the dramatically decreased incubation period (3-6h) and the superior analytical range of both assays compared to the standard BOD5 assay.

  8. 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

    Schwing, Carl M.

    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…

  9. Towards energy positive wastewater treatment by sludge treatment using free nitrous acid.

    PubMed

    Wang, Qilin; Hao, Xiaodi; Yuan, Zhiguo

    2016-02-01

    Free nitrous acid (FNA i.e. HNO2) was revealed to be effective in enhancing biodegradability of secondary sludge. Also, nitrite-oxidizing bacteria were found to be more susceptible to FNA than ammonium-oxidizing bacteria. Based on these findings, a novel FNA-based sludge treatment technology is proposed to enhance energy recovery from wastewater/sludge. Energy analysis indicated that the FNA-based technology would make wastewater treatment become an energy generating process (yielding energy at 4 kWh/PE/y; kWh/PE/y: kilowatt hours per population equivalent per year), rather than being a large energy consumer that it is today (consuming energy at 24 kWh/PE/y). Importantly, FNA required for the sludge treatment could be produced as a by-product of wastewater treatment. This proposed FNA-based technology is economically and environmentally attractive, and can be easily implemented in any wastewater treatment plants. It only involves the installation of a simple sludge mixing tank. This article presents the concept of the FNA-based technology.

  10. Co-conditioning of the anaerobic digested sludge of a municipal wastewater treatment plant with alum sludge: benefit of phosphorus reduction in reject water.

    PubMed

    Yang, Y; Zhao, Y Q; Babatunde, A O; Kearney, P

    2007-12-01

    In this study, alum sludge was introduced to co-conditioning and dewatering with an anaerobic digested sludge from a municipal wastewater treatment plant, to examine the role of the alum sludge in improving the dewaterbility of the mixed sludge and also in immobilizing phosphorus in the reject water. Experiments have demonstrated that the optimal mix ratio for the two sludges is 2:1 (anaerobic digested sludge:alum sludge: volume basis), and this can bring approximately 99% phosphorus reduction in the reject water through the adsorption of phosphorus by alum in the sludge. The phosphorus loading in wastewater treatment plants is itself derived from the recycling of reject water during the wastewater treatment process. Consequently, this co-conditioning and dewatering strategy can achieve a significant reduction in phosphorus loading in wastewater treatment plants. In addition, the use of the alum sludge has been shown to beneficially enhance the dewaterability of the resultant mixed sludge, by decreasing both the specific resistance to filtration and the capillary suction time. This is attributed to the alum sludge acting in charge neutralization and/or as adsorbent for phosphate in the aqueous phase of the sludge. Experiments have also demonstrated that the optimal polymer (Superfloc C2260, Cytec, Botlek, Netherlands) dose for the anaerobic digested sludge was 120 mg/L, while the optimal dose for the mixed sludge (mix ratio 2:1) was 15 mg/L, highlighting a huge savings in polymer addition. Therefore, from the technical perspective, the co-conditioning and dewatering strategy can be viewed as a "win-win" situation. However, for its full-scale application, integrated cost-effective analysis of process capabilities, sludge transport, increased cake disposal, additional administration, polymer saving, and so on, should be factored in.

  11. A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant.

    PubMed

    Tamis, J; van Schouwenburg, G; Kleerebezem, R; van Loosdrecht, M C M

    2011-11-15

    Sludge predation can be an effective solution to reduce sludge production at a wastewater treatment plant. Oligochaete worms are the natural consumers of biomass in benthic layers in ecosystems. In this study the results of secondary sludge degradation by the aquatic Oligochaete worm Aulophorus furcatus in a 125 m(3) reactor and further sludge conversion in an anaerobic tank are presented. The system was operated over a period of 4 years at WWTP Wolvega, the Netherlands and was fed with secondary sludge from a low loaded activated sludge process. It was possible to maintain a stable and active population of the aquatic worm species A. furcatus during the full period. Under optimal conditions a sludge conversion of 150-200 kg TSS/d or 1.2-1.6 kg TSS/m(3)/d was established in the worm reactor. The worms grew as a biofilm on carrier material in the reactor. The surface specific conversion rate reached 140-180 g TSS/m(2)d and the worm biomass specific conversion rate was 0.5-1 g TSS sludge/g dry weight worms per day. The sludge reduction under optimal conditions in the worm reactor was 30-40%. The degradation by worms was an order of magnitude larger than the endogenous conversion rate of the secondary sludge. Effluent sludge from the worm reactor was stored in an anaerobic tank where methanogenic processes became apparent. It appeared that besides reducing the sludge amount, the worms' activity increased anaerobic digestibility, allowing for future optimisation of the total system by maximising sludge reduction and methane formation. In the whole system it was possible to reduce the amount of sludge by at least 65% on TSS basis. This is a much better total conversion than reported for anaerobic biodegradability of secondary sludge of 20-30% efficiency in terms of TSS reduction.

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

    PubMed

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

    2015-01-15

    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 μg/kg dm, respectively) while the mean concentrations found in the other types of sewage sludge were 70 μg/kg dm (aerobically-digested sludge), 63 μg/kg dm (lagoon sludge), 12 μg/kg dm (composted sludge) and 8 μg/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 μg/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, 17α-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

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

    PubMed

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

    2007-03-01

    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.

  14. Increasing the sludge energy potential of wastewater treatment plants by introducing fine mesh sieves for primary treatment.

    PubMed

    Paulsrud, Bjarne; Rusten, Bjørn; Aas, Bjørn

    2014-01-01

    The objective of this study was to compare some basic characteristics of sludge from fine mesh sieves (sieve sludge) with sludge from primary clarifiers (primary sludge) regarding their energy potential with a focus on anaerobic digestion and/or incineration. Nineteen samples of sludge from fine mesh sieve plants (most of them without fine screens and grit chambers as pre-treatment) and 10 samples of primary sludge were analysed for the content of dry solids (DS), volatile solids (VS), chemical oxygen demand (COD), calorific value and methane potential. The results demonstrated that the sieve sludges have significantly higher VS content and higher methane potential than primary sludges, clearly indicating an increased sludge energy potential if fine mesh sieves are used for primary treatment instead of primary clarifiers at wastewater treatment plants with anaerobic digesters. If the sludges from primary treatment are to be incinerated or used as fuel in cement kilns, there is no significant difference in energy potential (given as calorific values) for the two types of primary treatment.

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

    PubMed

    Basibuyuk, M; Kalat, D G

    2004-03-01

    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 sludge acted as a coagulant and excellent oil and grease, COD and TSS removal efficiencies were obtained. The optimum conditions were a pH of 6 and a sludge dose of 1100 mg SS l(-1). The efficiency of sludge was also compared with alum and ferric chloride for the vegetable oil refinery wastewater. At doses of 1300-1900 mg SS l(-1), the sludge was as effective as ferric chloride and alum at removing oil and grease, COD, and TSS. In addition, various combinations of ferric chloride and waterworks sludge were also examined. Under the condition of 12.5 mg l(-1) fresh ferric chloride and 1000 mg SS l(-1) sludge dose, 99% oil and grease 99% TSS and 83% COD removal efficiencies were obtained.

  16. Liquidization of dewatered organic sludge and anaerobic treatment

    SciTech Connect

    Sawayama, Shigeki; Inoue, Seiichi; Ogi, Tomoko

    1996-12-31

    Dewatered sewage sludge was thermochemically liquidized at 175 {degrees}C and the liquidized sludge was separated by centrifugation to 58% (w/w) supernatant and 42% precipitate. The amount of proteins in the liquidized sludge slightly decreased through the liquidization process, however, that of lipids increased. The supernatant separated from the sludge liquidized with dewatered sewage sludge was successfully anaerobically digested. Biogas yield from the supernatant from dewatered sewage sludge at organic loading concentrations of 1.9-2.2 g VS/l during 9 days incubation was 440 ml/g-added VS and digestion ratio was 66% (w/w). Biogas yield in the case of dewatered sewage sludge was 257 ml/g-added VS and digestion ratio was 45%. Similar results were obtained in the case of the anaerobically digested with sewage sludge and dewatered sludge. Anaerobic digestion of the supernatants from the liquidized sludges resulted in high biogas productivity and high digestion ratio compared with these of the original sludges. Moreover, the precipitates contained lower moisture, therefore, they can be incinerated easier than the respective original sludges.

  17. Co-digestion of domestic kitchen waste and night soil sludge in a full-scale sludge treatment plant.

    PubMed

    Yoneyama, Y; Takeno, K

    2002-01-01

    A study was made on the domestic kitchen waste and night soil treatment performance of a full-scale sludge treatment plant. The sludge treatment at this plant was by thermophilic methane fermentation. The initial treatment, mesophilic to thermophilic fermentation, was able to be started up within a short time by adjusting the amount of influent waste. Thermophilic methane fermentation was carried out for five months (May-October) and the performance under a mean residual time of 22 days indicated a VTS decomposition of 42%, gas generation of 54-1,610 m3/day (average: 755 m3/day), and a mean methane concentration of 60%. The methane gas was used to generate power in the plant and the amount of power generated by methane gas was highest in October (average of 1,200 kWh/day). This was equivalent to about 7% of the power consumed at the entire sludge treatment plant. The BOD/NH4-N of the activated sludge influent water was lower, compared to a case where there is no recycle flow, due to the recycle flow from the methane fermentation process. There was, therefore, a tendency for an increase in the amount of methanol charged into the secondary denitrification tank. However, the quality of the effluent was satisfactory (BOD< 10 mg/L, SS< 5 mg/L, and T-N< 25 mg/L). Study results indicated that it was possible to implement a full-scale plant for recovering organic waste.

  18. Effect of microwave pre-treatment of thickened waste activated sludge on biogas production from co-digestion of organic fraction of municipal solid waste, thickened waste activated sludge and municipal sludge.

    PubMed

    Ara, E; Sartaj, M; Kennedy, K

    2014-12-01

    Anaerobic co-digestion of organic fraction of municipal solid waste, with thickened waste activated sludge and primary sludge has the potential to enhance biodegradation of solid waste, increase longevity of existing landfills and lead to more sustainable development by improving waste to energy production. This study reports on mesophilic batch and continuous studies using different concentrations and combinations (ratios) of organic fraction of municipal solid waste, thickened waste activated sludge (microwave pre-treated and untreated) and primary sludge to assess the potential for improved biodegradability and specific biogas production. Improvements in specific biogas production for batch assays, with concomitant improvements in total chemical oxygen demand and volatile solid removal, were obtained with organic fraction of municipal solid waste:thickened waste activated sludge:primary sludge mixtures at a ratio of 50:25:25 (with and without thickened waste activated sludge microwave pre-treatment). This combination was used for continuous digester studies. At 15 d hydraulic retention times, the co-digestion of organic fraction of municipal solid waste:organic fraction of municipal solid waste:primary sludge and organic fraction of municipal solid waste:thickened waste activated sludge microwave:primary sludge resulted in a 1.38- and 1.46-fold increase in biogas production and concomitant waste stabilisation when compared with thickened waste activated sludge:primary sludge (50:50) and thickened waste activated sludge microwave:primary sludge (50:50) digestion at the same hydraulic retention times and volumetric volatile solid loading rate, respectively. The digestion of organic fraction of municipal solid waste with primary sludge and thickened waste activated sludge provides beneficial effects that could be implemented at municipal wastewater treatment plants that are operating at loading rates of less than design capacity.

  19. SLUDGE TREATMENT PROJECT ENGINEERED CONTAINER RETRIEVAL AND TRANSFER SYSTEM PRELIMINARY DESIGN HAZARD ANALYSIS SUPPLEMENT 1

    SciTech Connect

    FRANZ GR; MEICHLE RH

    2011-07-18

    This 'What/If' Hazards Analysis addresses hazards affecting the Sludge Treatment Project Engineered Container Retrieval and Transfer System (ECRTS) NPH and external events at the preliminary design stage. In addition, the hazards of the operation sequence steps for the mechanical handling operations in preparation of Sludge Transport and Storage Container (STSC), disconnect STSC and prepare STSC and Sludge Transport System (STS) for shipping are addressed.

  20. Net positive energy wastewater treatment plant via thermal pre-treatment of sludge: A theoretical case study.

    PubMed

    Farno, Ehsan; Baudez, Jean Christophe; Parthasarathy, Rajarathinam; Eshtiaghi, Nicky

    2017-01-13

    In a wastewater treatment process, energy is mainly used in sludge handling and heating, while energy is recovered by biogas production in anaerobic digestion process. Thermal pre-treatment of sludge can change the energy balance in a wastewater treatment process since it reduces the viscosity and yield stress of sludge and increases the biogas production. In this study, a calculation based on a hypothetical wastewater treatment plant is provided to show the possibility of creating a net positive energy wastewater treatment plant as a result of implementing thermal pre-treatment process before the anaerobic digester. The calculations showed a great energy saving in pumping and mixing of the sludge by thermal pre-treatment of sludge before anaerobic digestion process.

  1. Re-use of water treatment works sludge to enhance particulate pollutant removal from sewage.

    PubMed

    Guan, Xiao-Hong; Chen, Guang-Hao; Shang, Chii

    2005-09-01

    This paper attempted to study the feasibility of reusing water treatment works sludge ("alum sludge") to improve particulate pollutant removal from sewage. The main issues focused upon were: (1) the appropriate dosage of the alum sludge, (2) the appropriate operating conditions, and (3) the possible mechanisms for enhancement by adding alum sludge. Actual alum sludge and sewage were applied to a series of jar tests conducted under various conditions. It has been found that both the SS and COD removal efficiencies could be improved by the addition of the alum sludge, which was mainly attributed to the removal of relatively fine particles with a size of 48-200 microm. The appropriate dosage of the alum sludge was determined to be 18-20 mg of Al/L. Increasing the mixing speed or reducing the floc size of the alum sludge enhanced the SS and COD removal and the dispersed alum sludge could remove particulate contaminants with smaller size than the raw sewage. ToF-SIMS evidence revealed that the aluminum species at the surface of the alum sludge were effectively utilized for improving the SS and COD removal. It was postulated that the sweep flocculation and/or the physical adsorption might play key roles in the enhancement of particulate pollutant removal from sewage.

  2. Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor.

    PubMed

    Ge, Huoqing; Batstone, Damien; Keller, Jurg

    2016-01-01

    The need to reduce energy input and enhance energy recovery from wastewater is driving renewed interest in high-rate activated sludge treatment (i.e. short hydraulic and solids retention times (HRT and SRT, respectively)). This process generates short SRT activated sludge stream, which should be highly degradable. However, the evaluation of anaerobic digestion of short SRT sludge has been limited. This paper assesses anaerobic digestion of short SRT sludge digestion derived from meat processing wastewater under thermophilic and mesophilic conditions. The thermophilic digestion system (55°C) achieved 60 and 68% volatile solids destruction at 8 day and 10 day HRT, respectively, compared with 50% in the mesophilic digestion system (35°C, 10 day HRT). The digestion effluents from the thermophilic (8-10 day HRT) and mesophilic systems were stable, as assessed by residual methane potentials. The ammonia rich sludge dewatering liquor was effectively treated by a batch anammox process, which exhibited comparable nitrogen removal rate as the tests using a control synthetic ammonia solution, indicating that the dewatering liquor did not have inhibiting/toxic effects on the anammox activity.

  3. Assessing dewatering performance of drinking water treatment sludges.

    PubMed

    Verrelli, David I; Dixon, David R; Scales, Peter J

    2010-03-01

    A comparison of the dewaterability of a range of water treatment plant sludges has been completed through computation of dewatering performance indicators for a diaphragm filter press. Real parameter data, obtained from the characterisation of alum and ferric sludges, generated under precisely controlled conditions, was used for input to a phenomenological model. Comparisons of dewaterability based on throughput curves largely agree with previous analysis of the underlying parameter data. The difference in approach provides a quantification of benefit. Greater throughputs and output concentrations are predicted at the lowest coagulant doses and at pH approximately 6. Typical industrial cloth resistances consistently reduce throughput by a factor of 3-7, but the assessment of relative benefit is shown to be insensitive to this parameter. Quantitative agreement of the predictions with observed performance can be attained. Finally, the twin effects of solids loading and dewaterability are assessed together, showing that each has a significant influence on the required filter surface area. This quantification shows that high coagulant doses adversely affect both of these aspects, leading to filter area requirements larger than might otherwise be expected.

  4. Treatment of pulp mill sludges by supercritical water oxidation

    SciTech Connect

    Modell, M.

    1990-07-01

    Supercritical water oxidation (SCWO) is new process that can oxidize organics very effectively at moderate temperatures (400 to 650{degree}C) and high pressure (3700 psi). It is an environmentally acceptable alternative for sludge treatment. In bench scale tests, total organic carbon (TOC) and total organic halide (TOX) reductions of 99 to 99.9% were obtained; dioxin reductions were 95 to 99.9%. A conceptual design for commercial systems has been completed and preliminary economics have been estimated. Comparisons confirm that SCWO is less costly than dewatering plus incineration for treating pulp mill sludges. SCWO can also compete effectively with dewatering plus landfilling where tipping fees exceed $35/yd{sup 3}. In some regions of the US, tipping fees are now $75/yd{sup 3} and rising steadily. In the 1995 to 2000 time frame, SCWO has a good chance of becoming the method of choice. MODEC's objective is to bring the technology to commercial availability by 1993. 10 refs., 6 figs., 19 tabs.

  5. Ecotoxicological evaluation of the bioleaching treatment of sewage sludges contaminated with heavy metals

    SciTech Connect

    Renoux, A.Y.; Tyagi, R.D.; Paquette, L.; Samson, R.

    1995-12-31

    A new decontamination technology of sewage sludge, the bioleaching of heavy metals, was assessed using ecotoxicity bioassays. Sewage sludges, treated or non-treated, were mixed with a non-contaminated soil used as a negative control at a rate of 1 to 100 g per liter of soil. Aqueous elutriates (TCLP) of the sludges were used for the aqueous bioassays. The bioleaching of metals reduced the toxic effects associated with sludge for most of the bioassays, although the sludge after treatment exhibited an inherent level of toxicity at high loading rates. With respect to seed germination, bioleached sludge was less toxic (EC50 barley: 53 g/L; lettuce: 13.6) than the non-treated (72; 16.8 g/L). The treated sludge stimulated the barley growth at > 5 6 g/L. The non-treated causes an inhibition at 100 g/L. Earthworms survived in up to 56 g/L of bioleached sludge, compared to 32 g/L of the non-treated. The Microtox{reg_sign} EC50s were 4.0% and 8.4% for nontreated and treated sludges respectively. No genotoxicity (SOS Chromotest) in the sludge elutriates was detected, and no significant treatment effects were noticeable using the lettuce root elongation bioassay. The Daphnia magna mortality of the elutriate was increased with sludge treatment. However, the lettuce root elongation and D. magna mortality bioassay results were difficult to interpret due to variability in standard deviations. This study demonstrated that the ecotoxicological battery of bioassays, and particularly direct contact bioassays, can be used to assess sewage sludge remediation technologies.

  6. Kinetics and advanced digester design for anaerobic digestion of water hyacinth and primary sludge

    SciTech Connect

    Chynoweth, D.P.; Dolenc, D.A.; Ghosh, S.; Henry, M.P.; Jerger, D.E.; Srivastava, V.J.

    1982-01-01

    A research program centered around a facility located at Walt Disney World (WDW) is in progress to evaluate the use of water hyacinth (WH) for secondary and tertiary wastewater treatment, to optimize growth of WH under these conditions, and to convert the resultant primary sludge (PS) and WH to methane via anaerobic digestion. This article describes the status of the biogasification component of this program, which includes baseline and advanced digestion experiments with individual feeds and blends and the design of an experimental test unit (ETU) to be installed at WDW. Experiments with several blends demonstrated that methane yields can be predicted from the fractional content and methane yield of each component. The process was found to adhere to the Monod kinetic model for microbial growth, and associated kinetic parameters were developed for various feed combinations. A novel upflow digester is achieving significantly higher conversion than a stirred-tank digester. Of several pretreatment techniques used, only alkaline treatment resulted in increased biodegradability. A larger scale (4.5 m/sup 3/) experimental test unit is being designed for installation at WDW in 1982. 13 figures, 4 tables.

  7. Physicochemical and thermal characteristics of the sludge produced after thermochemical treatment of petrochemical wastewater.

    PubMed

    Verma, Shilpi; Prasad, Basheshwar; Mishra, I M

    2012-01-01

    The present work describes the physicochemical and thermal characteristics of the sludge generated after thermochemical treatment of wastewater from a petrochemical plant manufacturing purified terephthalic acid (PTA). Although FeCl3 was found to be more effective than CuSO4 in removing COD from wastewater, the settling and filtration characteristics of FeCl3 sludge were poorer. Addition of cationic polyacrylamide (CPAA; 0.050kg/m3) to the FeCl3 wastewater system greatly improved the values of the filter characteristics of specific cake resistance (1.2 x 10(8) m/kg) and resistance of filter medium (9.9 x 10(8) m(-1)) from the earlier values of 1.9 x 10(9) m/kg and 1.7 x 10(8) m(-1), respectively. SEM-EDAX and FTIR studies were undertaken, to understand the sludge structure and composition, respectively. The moisture distribution in the CuSO4 sludge, FeCl3 sludge and FeCl3 + CPAA sludge showed that the amount of bound water content in the CuSO4 and FeCl3 + CPAA sludges is less than that of the FeCl3 sludge and there was a significant reduction in the solid-water bond strength of FeCl3 + CPAA sludge, which was responsible for better settling and filtration characteristics. Due to the hazardous nature of the sludge, land application is not a possible route of disposal. The thermal degradation behaviour of the sludge was studied for its possible use as a co-fuel. The studies showed that degradation behaviour of the sludge was exothermic in nature. Because of the exothermic nature of the sludge, it can be used in making fuel briquettes or it can be disposed of via wet air oxidation.

  8. Evaluation of a microwave based reactor for the treatment of blackwater sludge

    PubMed Central

    Mawioo, Peter M.; Rweyemamu, Audax; Garcia, Hector A.; Hooijmans, Christine M.; Brdjanovic, Damir

    2016-01-01

    A laboratory-scale microwave (MW) unit was applied to treat fresh blackwater sludge that represented fecal sludge (FS) produced at heavily used toilet facilities. The sludge was exposed to MW irradiation at different power levels and for various durations. Variables such as sludge volume and pathogen reduction were observed. The results demonstrated that the MW is a rapid and efficient technology that can reduce the sludge volume by over 70% in these experimental conditions. The concentration of bacterial pathogenic indicator E. coli also decreased to below the analytical detection levels. Furthermore, the results indicated that the MW operational conditions including radiation power and contact time can be varied to achieve the desired sludge volume and pathogen reduction. MW technology can be further explored for the potential scaling-up as an option for rapid treatment of FS from intensively used sanitation facilities such as in emergency situations. PMID:26799809

  9. Relationship between pollutant content and ecotoxicity of sewage sludges from Spanish wastewater treatment plants.

    PubMed

    Roig, Neus; Sierra, Jordi; Nadal, Martí; Martí, Esther; Navalón-Madrigal, Pedro; Schuhmacher, Marta; Domingo, José L

    2012-05-15

    Chemical and ecotoxicological properties of 28 sewage sludge samples from Spanish wastewater treatment plants were studied in order to assess their suitability for agricultural purposes. Sludge samples were classified into five categories according to specific treatment processes in terms of digestion (aerobic/anaerobic) and drying (mechanical/thermal). Composted samples, as indicative of the most refined process, were also considered. Sludges were subjected to physical-chemical characterization, being the sludge stabilization degree respirometrically assessed. The concentrations of seven metals (Cd, Cr, Cu, Pb, Zn, Ni, Hg) and organic substances (phenolic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated naphthalenes, polybrominated diphenyl ethers, and perfluorinated compounds) were determined. Finally, two ecotoxicological tests were performed: i) Microtox® toxicity test with Vibrio fischeri, and ii) root elongation test with Allium cepa, Lolium perenne and Raphanus sativus seeds. Significant differences were found in the following parameters: dry matter, electrical conductivity, nitrogen, organic matter and its stability, phytotoxicity and ecotoxicity, depending on the sludge treatment. In turn, no significant differences were found between categories in the concentrations of most metals and organic pollutants, with the exception of free phenolic compounds. Furthermore, no correlation between total heavy metal burden and ecotoxicity was observed. However, a good correlation was found between phenolic compounds and most ecotoxicological tests. These results suggest that sludge stability (conditioned by sludge treatment) might have a greater influence on sludge ecotoxicity than the pollutant load. Composting was identified as the treatment resulting in the lowest toxicity.

  10. Comparative study of ground water treatment plants sludges to remove phosphorous from wastewater.

    PubMed

    Bal Krishna, K C; Aryal, Ashok; Jansen, Troy

    2016-09-15

    Alum- and iron-based sludge obtained from water treatment plant produced during a unit treatment process (coagulation and flocculation) have been widely tested as a low-cost adsorbent to remove phosphorous (P) from wastewater. However, the effectiveness of iron-based sludge generated from the oxidation of iron which naturally occurs in the ground water has not been investigated. Moreover, influences of dominant metals ions comprised in the treatment plants sludges on P adsorption capacity and rate from wastewater are not yet known. This study, therefore, employed four different groundwater treatment plants sludges iron-based (from the oxidation of iron) and alum-based (from coagulation and flocculation process) to determine their P adsorption capacities and adsorption rates from the synthetic wastewater (SWW) and secondary effluent wastewater (SEWW). Although metals ions concentrations were the highest in the iron-based sludge amongst the sludge used in this study, it appeared to have the lowest P adsorption capacity and adsorption rate. A good correlation between aluminium to iron mass ratio and adsorption capacity for both types of waters were noted. However, a poor relation between aluminium to iron mass ratio and adsorption rates for the SEWW was observed. Further, the tested sludges were found to have a better P removal efficiency and adsorption capacity from the SEWW than from the SWW. Thus, this study demonstrates the ground water treatment plants sludges could be a low cost and effective adsorbent in removing P from wastewater.

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

    PubMed Central

    2012-01-01

    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

  12. Sludge reduction in a small wastewater treatment plant by electro-kinetic disintegration.

    PubMed

    Chiavola, Agostina; Ridolfi, Alessandra; D'Amato, Emilio; Bongirolami, Simona; Cima, Ennio; Sirini, Piero; Gavasci, Renato

    2015-01-01

    Sludge reduction in a wastewater treatment plant (WWTP) has recently become a key issue for the managing companies, due to the increasing constraints on the disposal alternatives. Therefore, all the solutions proposed with the aim of minimizing sludge production are receiving increasing attention and are tested either at laboratory or full-scale to evaluate their real effectiveness. In the present paper, electro-kinetic disintegration has been applied at full-scale in the recycle loop of the sludge drawn from the secondary settlement tank of a small WWTP for domestic sewage. After the disintegration stage, the treated sludge was returned to the biological reactor. Three different percentages (50, 75 and 100%) of the return sludge flow rate were subjected to disintegration and the effects on the sludge production and the WWTP operation efficiency evaluated. The long-term observations showed that the electro-kinetic disintegration was able to drastically reduce the amount of biological sludge produced by the plant, without affecting its treatment efficiency. The highest reduction was achieved when 100% return sludge flow rate was subjected to the disintegration process. The reduced sludge production gave rise to a considerable net cost saving for the company which manages the plant.

  13. Fate of heavy metals and major nutrients in a sludge-soil-plant-leachate system during the sludge phyto-treatment process.

    PubMed

    Xu, Tianfen; Qiu, Jinrong; Wu, Qi-Tang; Guo, Xiaofang; Wei, Zebin; Xie, Fangwen; Wong, Jonathan W C

    2013-01-01

    Land application of sewage sludge usually leads to increased levels of heavy metals in soil, plants and groundwater. Pre-treatment using plants has been proposed to reduce the contents of heavy metals and water in sludge prior to land application. This study quantified the transfer of Zn, Cd, Pb and major nutrients in a sludge-soil-plant-leachate system during the treatment of sewage sludge. To accomplish this, a two year pot experiment was carried out to collect leachate, mono- and co-cropping of Sedum alfredii and feed crops was conducted in sludge with an under-layer soil support. Sludge phyto-treatment increased Zn and Cd concentrations in the under-layer soil, but not Pb. Specifically, 70%, 70% and 80% of the original Zn, Cd and Pb, respectively, remained in the sludge, while about 40%, 70% and 60% of the original N, P and K remained. Only 3% to 5% of Cd and Zn and < 1% of Pb were transferred into the under-layer soils or leachates, while more than 12% of the N and P were transferred. Co-planting S. alfredii and feed crops led to a significant reduction of heavy metals in leachates when compared with sludge without planting. Overall, sludge leachate is more appropriate than whole sludge for recycling in agriculture since it reduces the chance of heavy metal contamination in the agro-ecosystem; therefore, co-cropping phytotreatment of sludge can be coupled with sludge leachate recycling for crop production and re-collection of the sludge residue for landfilling.

  14. Land treatment field studies. Volume 5. Wastewater treatment sludge from batch organic chemical synthesis. Final report Sep 77-Feb 81

    SciTech Connect

    Berkowitz, J.B.; Bysshe, S.E.; Goodwin, B.E.; Harris, J.C.; Land, D.B.

    1983-07-01

    This report presents the results of field measurements and observations of a land treatment operation using a sludge generated from organic chemical manufacture. The sludge is applied to a turf farm which contains acidic soil; the sludge reduces the lime addition requirements for pH adjustment. The sub-soils are porous and the quality of the groundwater located at 20-30' below the ground surface is pristine.

  15. DEMONSTRATION BULLETIN: THE BASIC EXTRACTIVE SLUDGE TREATMENT (B.E.S.T.) RESOURCES CONSERVATION COMPANY (RCC)

    EPA Science Inventory

    The Basic Extractive Sludge Treatment (B.E.S.T.®) process is a solvent extraction system that separates organic contaminants from sludges, soils, and sediments. The primary distinguishing feature of the process is the extraction agent, triethylamine. The key to the success of tri...

  16. Fate of Malathion in an Activated Sludge Municipal Wastewater Treatment System

    DTIC Science & Technology

    2013-03-01

    1. The degradation of malathion by municipal WWTP AS a) The capacity for AS to degrade malathion b) Degradation kinetics of AS with respect to...abiotically. Sorption kinetics and isotherm experiments resulted in negligible malathion sorption to AS minimizing the potential for sludge...FATE OF MALATHION IN AN ACTIVATED SLUDGE MUNICIPAL WASTEWATER TREATMENT SYSTEM THESIS

  17. Belt Filtration. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Broste, Dale

    This lesson, an introduction to belt management, was developed for a course in sludge treatment and disposal. Fundamental principles of belt filter operation are described. Chemical conditioning and the effect on sludge characteristics are discussed, and a detailed description of the different zones of dewatering is presented. Information on…

  18. Thermo-Oxidization of Municipal Wastewater Treatment Plant Sludge for Production of Class A Biosolids

    EPA Science Inventory

    Bench-scale reactors were used to test a novel thermo-oxidation process on municipal wastewater treatment plant (WWTP) waste activated sludge (WAS) using hydrogen peroxide (H2O2) to achieve a Class A sludge product appropriate for land application. Reactor ...

  19. Electro-coagulation treatment of oily wastewater with sludge analysis.

    PubMed

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

    2012-01-01

    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.

  20. Enhancement of methane production in mesophilic anaerobic digestion of secondary sewage sludge by advanced thermal hydrolysis pretreatment.

    PubMed

    Abelleira-Pereira, Jose M; Pérez-Elvira, Sara I; Sánchez-Oneto, Jezabel; de la Cruz, Roberto; Portela, Juan R; Nebot, Enrique

    2015-03-15

    Studies on the development and evolution of anaerobic digestion (AD) pretreatments are nowadays becoming widespread, due to the outstanding benefits that these processes could entail in the management of sewage sludge. Production of sewage sludge in wastewater treatment plants (WWTPs) is becoming an extremely important environmental issue. The work presented in this paper is a continuation of our previous studies with the aim of understanding and developing the advanced thermal hydrolysis (ATH) process. ATH is a novel AD pretreatment based on a thermal hydrolysis (TH) process plus hydrogen peroxide (H2O2) addition that takes advantage of a peroxidation/direct steam injection synergistic effect. The main goal of the present research was to compare the performance of TH and ATH, conducted at a wide range of operating conditions, as pretreatments of mesophilic AD with an emphasis on methane production enhancement as a key parameter and its connection with the sludge solubilization. Results showed that both TH and ATH patently improved methane production in subsequent mesophilic BMP (biochemical methane potential) tests in comparison with BMP control tests (raw secondary sewage sludge). Besides other interesting results and discussions, a promising result was obtained since ATH, operated at temperature (115 °C), pretreatment time (5 min) and pressure (1 bar) considerably below those typically used in TH (170 °C, 30 min, 8 bar), managed to enhance the methane production in subsequent mesophilic BMP tests [biodegradability factor (fB) = cumulative CH4production/cumulative CH4production (Control) = 1.51 ± 0.01] to quite similar levels than conventional TH pretreatment [fB = 1.52 ± 0.03].

  1. SLUDGE TREATMENT PROJECT ENGINEERED CONTAINER RETRIEVAL AND TRANSFER SYSTEM PRELMINARY DESIGN HAZARD AND OPERABILITY STUDY

    SciTech Connect

    CARRO CA

    2011-07-15

    This Hazard and Operability (HAZOP) study addresses the Sludge Treatment Project (STP) Engineered Container Retrieval and Transfer System (ECRTS) preliminary design for retrieving sludge from underwater engineered containers located in the 105-K West (KW) Basin, transferring the sludge as a sludge-water slurry (hereafter referred to as 'slurry') to a Sludge Transport and Storage Container (STSC) located in a Modified KW Basin Annex, and preparing the STSC for transport to T Plant using the Sludge Transport System (STS). There are six, underwater engineered containers located in the KW Basin that, at the time of sludge retrieval, will contain an estimated volume of 5.2 m{sup 3} of KW Basin floor and pit sludge, 18.4 m{sup 3} of 105-K East (KE) Basin floor, pit, and canister sludge, and 3.5 m{sup 3} of settler tank sludge. The KE and KW Basin sludge consists of fuel corrosion products (including metallic uranium, and fission and activation products), small fuel fragments, iron and aluminum oxide, sand, dirt, operational debris, and biological debris. The settler tank sludge consists of sludge generated by the washing of KE and KW Basin fuel in the Primary Clean Machine. A detailed description of the origin of sludge and its chemical and physical characteristics can be found in HNF-41051, Preliminary STP Container and Settler Sludge Process System Description and Material Balance. In summary, the ECRTS retrieves sludge from the engineered containers and hydraulically transfers it as a slurry into an STSC positioned within a trailer-mounted STS cask located in a Modified KW Basin Annex. The slurry is allowed to settle within the STSC to concentrate the solids and clarify the supernate. After a prescribed settling period the supernate is decanted. The decanted supernate is filtered through a sand filter and returned to the basin. Subsequent batches of slurry are added to the STSC, settled, and excess supernate removed until the prescribed quantity of sludge is collected

  2. Anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge and the microbial community structure.

    PubMed

    Ju, Feng; Wang, Yubo; Lau, Frankie T K; Fung, W C; Huang, Danping; Xia, Yu; Zhang, Tong

    2016-10-01

    The effectiveness and treatment conditions of FeCl3- and AlCl3-coagulated municipal sewage sludge from chemically enhanced primary treatment (CEPT) using anaerobic digestion (AD) and the structure of microbial community were investigated. The results based on 297 measurements under different operational conditions demonstrate good average AD performance of CEPT sludge, that is, percent volatile solid reduction of 58 %, specific biogas production (or biogas yield) of 0.92 m(3)/kg volatile solids (VS) destroyed, and methane content of 65.4 %. FeCl3 dosing, organic loading rate, temperature, and hydraulic retention time all significantly affected AD performance. FeCl3 dosing greatly improved specific methane production (methane yield) by 38-54 % and significantly reduced hydrogen sulfide (H2S) content in biogas (from up to 13,250 to <200 ppm), contributing to higher methane recovery and simplified biogas cleaning for power generation. Metagenomic analysis suggested that anaerobic digesters of both CEPT sludge and combined primary and secondary sludge were dominated by Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, Thermotogae, and Chloroflexi. However, Methanomicrobia methanogens were better enriched in the anaerobic digesters of CEPT sludge than in the combined sludge. Further, different sources of CEPT sludge with various chemical properties nurtured shared and unique microbial community composition. Combined, this study supports AD as an efficient technology for CEPT sludge treatment and poses first insights into the microbial community structure.

  3. Arsenic in an Alkaline AMD Treatment Sludge: Characterization and Stability Under Prolonged Anoxic Conditions

    SciTech Connect

    Beauchemin, S.; Fiset, J; Poirier, G; Ablett, J

    2010-01-01

    Lime treatment of acid mine drainage (AMD) generates large volumes of neutralization sludge that are often stored under water covers. The sludge consists mainly of calcite, gypsum and a widespread ferrihydrite-like Fe phase with several associated species of metal(loid) contaminants. The long-term stability of metal(loid)s in this chemically ill-defined material remains unknown. In this study, the stability and speciation of As in AMD sludge subjected to prolonged anoxic conditions is determined. The total As concentration in the sludge is 300 mg kg{sup -1}. In the laboratory, three distinct water cover treatments were imposed on the sludge to induce different redox conditions (100%N{sub 2}, 100%N{sub 2} + glucose, 95%N{sub 2}:5%H{sub 2}). These treatments were compared against a control of oxidized, water-saturated sludge. Electron micro-probe (EMP) analysis and spatially resolved synchrotron X-ray fluorescence (SXRF) results indicate that As is dominantly associated with Fe in the sludge. In all treatments and throughout the experiment, measured concentrations of dissolved As were less than 5 {micro}g L{sup -1}. Dissolved Mn concentration in the N{sub 2} + glucose treatment increased significantly compared to other treatments. Manganese and As K-edge X-ray absorption near edge structure spectroscopy (XANES) analyses showed that Mn was the redox-active element in the solid-phase, while As was stable. Arsenic(V) was still the dominant species in all water-covered sludges after 9 months of anoxic treatments. In contrast, Mn(IV) in the original sludge was partially reduced into Mn(II) in all water-covered sludges. The effect was most pronounced in the N{sub 2} + glucose treatment, suggesting microbial reduction. Micro-scale SXRF and XANES analysis of the treated sludge showed that Mn(II) accumulated in areas already enriched in Fe and As. Overall, the study shows that AMD sludges remain stable under prolonged anoxic conditions. External sources of chemical reductants

  4. A review of thermal sludge pre-treatment processes to improve dewaterability.

    PubMed

    Neyens, E; Baeyens, J

    2003-03-17

    As a result of the wide application and utilization of the waste activated sludge process, excess sludge presents a serious disposal problem. Many efforts have been devoted to reduce the excess sludge by treatments such as digestion and dewatering. It has been known for many years that a thermal pre-treatment gives an improvement in the dewaterability of sludges. This paper provides a literature review concerning the optimum treatment conditions to obtain enhanced dewaterability and digestibility of sludge. The main commercial hydrolysis processes (Cambi, Porteous and Zimpro) are discussed. The literature findings concerning the optimum treatment conditions of thermal or thermochemical pre-treatments are reviewed. The second part of this paper deals with the fundamentals of improving sludge dewatering. The influence of extracellular polymer (ECP) on settling and dewatering characteristics is discussed, together with the importance of cations and ECP-hydrophobicity in the flocculation and dewatering process. Finally, the effect on exocellular polymer, dewaterability, settleability and colloidal stability of activated sludge by treatment with sulfuric acid was studied.

  5. Effects of heat treatment on microbial communities of granular sludge for biological hydrogen production.

    PubMed

    Alibardi, Luca; Favaro, Lorenzo; Lavagnolo, Maria Cristina; Basaglia, Marina; Casella, Sergio

    2012-01-01

    Dark fermentation shares many features with anaerobic digestion with the exception that to maximize hydrogen production, methanogens and hydrogen-consuming bacteria should be inhibited. Heat treatment is widely applied as an inoculum pre-treatment due to its effectiveness in inhibiting methanogenic microflora but it may not exclusively select for hydrogen-producing bacteria. This work evaluated the effects of heat treatment on microbial viability and structure of anaerobic granular sludge. Heat treatment was carried out on granular sludge at 100 °C with four residence times (0.5, 1, 2 and 4 h). Hydrogen production of treated sludges was studied from glucose by means of batch test at different pH values. Results indicated that each heat treatment strongly influenced the granular sludge resulting in microbial communities having different hydrogen productions. The highest hydrogen yields (2.14 moles of hydrogen per mole of glucose) were obtained at pH 5.5 using the sludge treated for 4 h characterized by the lowest CFU concentration (2.3 × 10(3)CFU/g sludge). This study demonstrated that heat treatment should be carefully defined according to the structure of the sludge microbial community, allowing the selection of highly efficient hydrogen-producing microbes.

  6. Acidic and hydrogen peroxide treatment of polyaluminum chloride (PACL) sludge from water treatment.

    PubMed

    Kwon, J H; Park, K Y; Park, J H; Lee, S H; Ahn, K H

    2004-01-01

    The water treatment sludge including coagulants cannot be easily removed by conventional dewatering methods. The possibility of hydrogen peroxide (H2O2) oxidation as a pretreatment to enhance the dewaterability of polyaluminum chloride (PACl) sludge from water works was investigated. H2O2 treatment alone was not effective but H2O2 treatment under acidic condition significantly reduced both the cake water content and specific resistance to filtration (SRF), indicating the enhancement of dewaterability and filterability. The filterability after acid/H2O2 treatment was comparable to polymer conditioning and even more dewatered cake than polymer conditioning was produced. By H202 combined with sulfuric acid (H2SO4), leached iron caused Fenton's reaction, which showed a potential to significantly reduce the amount of solids mass and to produce more compact cake with higher filterability.

  7. Effect of Cu species on leaching behavior of simulated copper sludge after thermal treatment: ESCA analysis.

    PubMed

    Chou, Jing-Dong; Lin, Chiou-Liang; Wey, Ming-Yen; Chang, Shih-Hsien

    2010-07-15

    The aim of this study is to evaluate the efficiency of thermal treatment on residual copper sludge after separation treatment. The toxicity characteristic leaching procedure (TCLP) concentration, pattern distribution and possible Cu species of simulated copper sludge were analyzed. Parameters such as different reaction time and temperature are also discussed in this study. The TCLP leaching results showed that the TCLP concentration of Cu in thermally treated simulated copper sludge decreased (T=900 degrees C) as the reaction time increased to 4 h. The sequential extraction results showed that the main fraction of raw simulated copper sludge was carbonate. When temperatures were 500 and 700 degrees C, the main fraction of thermally treated simulated copper sludge was also carbonate. The percentage of Fe-Mn oxides and residue increased when T=900 degrees C. Electron Spectroscopy for Chemical Analysis (ESCA) showed that the possible Cu species of raw simulated copper sludge was Cu(OH)(2). The main possible Cu species of thermally treated simulated copper sludge were CuO and Cu(2)O when T was 500 and 700 degrees C, respectively. CuO, Cu(2)O, and Cu(3)O(2) were the possible Cu species in thermally treated simulated copper sludge when T=900 degrees C.

  8. Options for reducing oil content of sludge from a petroleum wastewater treatment plant.

    PubMed

    Kwon, Tae-Soon; Lee, Jae-Young

    2015-10-01

    Wastewater treatment plants at petroleum refineries often produce substantial quantities of sludge with relatively high concentrations of oil. Disposal of this waste is costly, in part because the high oil content requires use of secure disposal methods akin to handling of hazardous wastes. This article examines the properties of oily sludge and evaluates optional methods for reducing the oil content of this sludge to enable use of lower cost disposal methods. To reduce the oil content or break the structure of oily sludge, preliminary lab-scale experiments involving mechanical treatment, surfactant extraction, and oxidation are conducted. By applying surfactants, approximately 36% to 45% of oils are extracted from oily sludge. Of this, about 33% of oils are rapidly oxidised via radiation by an electron beam within 10 s of exposure. The Fenton reaction is effective for destruction of oily sludge. It is also found that 56% of oils were removed by reacting oily sludge with water containing ozone of 0.5 mg l(-1) over a period of 24 h. Oxidation using ozone thus can also be effectively used as a pretreatment for oily sludge.

  9. Recent development in the treatment of oily sludge from petroleum industry: a review.

    PubMed

    Hu, Guangji; Li, Jianbing; Zeng, Guangming

    2013-10-15

    Oily sludge is one of the most significant solid wastes generated in the petroleum industry. It is a complex emulsion of various petroleum hydrocarbons (PHCs), water, heavy metals, and solid particles. Due to its hazardous nature and increased generation quantities around the world, the effective treatment of oily sludge has attracted widespread attention. In this review, the origin, characteristics, and environmental impacts of oily sludge were introduced. Many methods have been investigated for dealing with PHCs in oily sludge either through oil recovery or sludge disposal, but little attention has been paid to handle its various heavy metals. These methods were discussed by dividing them into oil recovery and sludge disposal approaches. It was recognized that no single specific process can be considered as a panacea since each method is associated with different advantages and limitations. Future efforts should focus on the improvement of current technologies and the combination of oil recovery with sludge disposal in order to comply with both resource reuse recommendations and environmental regulations. The comprehensive examination of oily sludge treatment methods will help researchers and practitioners to have a good understanding of both recent developments and future research directions.

  10. Sludge minimization using aerobic/anoxic treatment technology

    SciTech Connect

    Mines, R.O. Jr.; Kalch, R.S.

    1999-07-01

    The objective of this investigation was to demonstrate through a bench-scale study that using an aerobic/anoxic sequence to treat wastewater and biosolids could significantly reduce the production of biosolids (sludge). A bench-scale activated sludge reactor and anoxic digester were operated for approximately three months. The process train consisted of a completely-mixed aerobic reactor with wasting of biosolids to an anoxic digester for stabilization. The system was operated such that biomass produced in the aerobic activated sludge process was wasted to the anoxic digester; and biomass produced in the anoxic digester was wasted back to the activated sludge process. A synthetic wastewater consisting of bacto-peptone nutrient broth was fed to the liquid process train. Influent and effluent to the aerobic biological process train were analytically tested, as were the contents of mixed liquor in the aerobic reactor and anoxic digester. Overall removal efficiencies for the activated sludge process with regard to COD, TKN, NH{sub 3}-N, and alkalinity averaged 91, 89, 98, and 38%, respectively. The overall average sludge production for the aerobic/anoxic process was 24% less than the overall average sludge production from a conventional activated sludge bench-scale system fed the same substrate and operated under similar mean cell residence times.

  11. Treatment of nitrous off-gas from dissolution of sludges

    SciTech Connect

    Flament, T.A.

    1998-08-25

    Several configurations have been reviewed for the NO{sub x} removal of dissolver off-gas. A predesign has been performed and operating conditions have been optimized. Simple absorption columns seems to be sufficient. NHC is in charge of the treatment of sludges containing mainly uranium dioxide and metallic uranium. The process is based on the following processing steps a dissolution step to oxidize the pyrophoric materials and to dissolve radionuclides (uranium, plutonium, americium and fission products), a solid/liquid separation to get rid of the insoluble solids (to be disposed at ERDF), an adjustment of the acid liquor with neutronic poisons, and neutralization of the acid liquor with caustic soda. The dissolution step generates a flow of nitrous fumes which was evaluated in a previous study. This NO{sub x} flow has to be treated. The purpose of this report is to study the treatment process of the nitrous vapors and to 0482 perform a preliminary design. Several treatment configurations are studied and the most effective process option with respect to the authorized level of discharge into atmosphere is discussed. As a conclusion, recommendations concerning the unit preliminary design are given.

  12. Treatment of municipal sewage sludge in supercritical water: A review.

    PubMed

    Qian, Lili; Wang, Shuzhong; Xu, Donghai; Guo, Yang; Tang, Xingying; Wang, Laisheng

    2016-02-01

    With increasing construction of wastewater treatment plants and stricter policies, municipal sewage sludge (MSS) disposal has become a serious problem. Treatment of MSS in supercritical water (SCW) can avoid the pre-drying procedure and secondary pollution of conventional methods. SCW treatment methods can be divided into supercritical water gasification (SCWG), supercritical water partial oxidation (SCWPO) and supercritical water oxidation (SCWO) technologies with increasing amounts of oxidants. Hydrogen-rich gases can be generated from MSS by SCWG or SCWPO technology using oxidants less than stoichiometric ratio while organic compounds can be completely degraded by SCWO technology with using an oxidant excess. For SCWG and SCWPO technologies, this paper reviews the influences of different process variables (MSS properties, moisture content, temperature, oxidant amount and catalysts) on the production of gases. For SCWO technology, this paper reviews research regarding the removal of organics with or without hydrothermal flames and the changes in heavy metal speciation and risk. Finally, typical systems for handling MSS are summarized and research needs and challenges are proposed.

  13. Life cycle GHG emissions of sewage sludge treatment and disposal options in Tai Lake Watershed, China.

    PubMed

    Liu, Beibei; Wei, Qi; Zhang, Bing; Bi, Jun

    2013-03-01

    The treatment and disposal of sewage sludge generate considerable amounts of greenhouse gases (GHGs) and pose environmental and economic challenges to wastewater treatment in China. To achieve a more informed and sustainable sludge management, this study conducts a life cycle inventory to investigate the GHG performances of six scenarios involving various sludge treatment technologies and disposal strategies. These scenarios are landfilling (S1), mono-incineration (S2), co-incineration (S3), brick manufacturing (S4), cement manufacturing (S5), and fertilizer for urban greening (S6). In terms of GHG emissions, S2 demonstrates the best performance with its large offset from sludge incineration energy recovery, followed by S4 and S6, whereas S1 demonstrates the poorest performance primarily because of its large quantity of methane leaks. The scenario rankings are affected by the assumptions of GHG offset calculation. In most scenarios, GHG performance could be improved by using waste gas or steam from existing facilities for drying sludge. Furthermore, considering the GHG performance along with economic, health, and other concerns, S6 is recommended. We thus suggest that local governments promote the use of composted sludge as urban greening fertilizers. In addition, the use of sludge with 60% water content, in place of the current standard of 80%, in wastewater treatment plants is proposed to be the new standard for Tai Lake Watershed in China.

  14. Manufacturing ceramic bricks with polyaluminum chloride (PAC) sludge from a water treatment plant.

    PubMed

    da Silva, E M; Morita, D M; Lima, A C M; Teixeira, L Girard

    2015-01-01

    The objective of this research work is to assess the viability of manufacturing ceramic bricks with sludge from a water treatment plant (WTP) for use in real-world applications. Sludge was collected from settling tanks at the Bolonha WTP, which is located in Belém, capital of the state of Pará, Brazil. After dewatering in drainage beds, sludge was added to the clay at a local brickworks at different mass percentages (7.6, 9.0, 11.7, 13.9 and 23.5%). Laboratory tests were performed on the bricks to assess their resistance to compression, water absorption, dimensions and visual aspects. Percentages of 7.6, 9.0, 11.7 and 13.9% (w/w) of WTP sludge presented good results in terms of resistance, which indicates that technically, ceramic bricks can be produced by incorporating up to 13.9% of WTP sludge.

  15. Ecotoxicity Assessment of Stabilized Sewage Sludge from Municipal Sewage Treatment Plant

    NASA Astrophysics Data System (ADS)

    Włodarczyk, Elżbieta; Próba, Marta; Wolny, Lidia

    2016-09-01

    Aim of this study was to evaluate the ecotoxicity of municipal sewage sludge conditioned with polyelectrolytes, taken from selected sewage treatment plant. Using the bioindication analysis overall toxicity was assessed, which allows to know the total toxicity of all the harmful substances contained in sewage sludge, in many cases acting synergistically. To prepare a sample of sludge for the basic test, all analyses were performed with a ratio of liquid to solid of 10:1 (water extract). Daphnia pulex biological screening test was used. A dilution series of an water extract of sludge were prepared to include within its scope the lowest concentration that causes 100% effect and the highest producing less than 10% of the effect within a specified range of the assay. The results of the test were read after 24 and 48 hours. Based on the research and analysis of test results it proved that the sewage sludge conditioned with polyelectrolytes exhibit the characteristics of eco-toxic.

  16. Water Treatment Plant Sludges--An Update of the State of the Art: Part 2.

    ERIC Educational Resources Information Center

    American Water Works Association Journal, 1978

    1978-01-01

    This report outlines the state of the art with respect to nonmechanical and mechanical methods of dewatering water treatment plant sludge, ultimate solids disposal, and research and development needs. (CS)

  17. Hygienization performances of innovative sludge treatment solutions to assure safe land spreading.

    PubMed

    Levantesi, C; Beimfohr, C; Blanch, A R; Carducci, A; Gianico, A; Lucena, F; Tomei, M C; Mininni, G

    2015-05-01

    The present research aims at the evaluation of the hygienization performances of innovative sludge treatment processes applied for the separated treatment of secondary sludge. Namely, two digestion pretreatments (sonication and thermal hydrolysis) and two sequential biological processes (mesophilic/thermophilic and anaerobic/aerobic digestion) were compared to the mesophilic (MAD) and thermophilic anaerobic digestion (TAD). Microbial indicators (Escherichia coli, somatic coliphages and Clostridium perfringens spores) and pathogens (Salmonella and enteroviruses), which show different resistances to treatment processes, were monitored in untreated and treated sludge. Overall, microbial load in secondary sludge was shown to be similar or lower than previously reported in literature for mixed sludge. Notably, the anaerobic/aerobic digestion process increased the removal of E. coli and somatic coliphages compared to the simple MAD and always achieved the hygienization requirement (2-log-unit removal of E. coli) proposed by EU Commission in the 3rd Working Document on sludge (April 2000) for the use of treated sludges in agriculture with restriction on their application. The microbial quality limits for the unrestricted use of sludge in agriculture (no Salmonella in 50 g wet weight (WW) and E. coli <500 CFU/g) were always met when thermal digestion or pretreatment was applied; however, the required removal level (6-log-unit removal of E. coli) could not be assessed due to the low level of this microorganism in raw sludge. Observed levels of indicator removal showed a higher resistance of viral particles to thermal treatment compared with bacterial cells and confirmed the suitability of somatic coliphages as indicators in thermal treatment processes.

  18. Anaerobic treatment of sludge from a nitrification-denitrification landfill leachate plant

    SciTech Connect

    Maranon, E. . E-mail: emara@uniovi.es; Castrillon, L.; Fernandez, Y.; Fernandez, E.

    2006-07-01

    The viability of anaerobic digestion of sludge from a MSW landfill leachate treatment plant, with COD values ranging between 15,000 and 19,400 mg O{sub 2} dm{sup -3}, in an upflow anaerobic sludge blanket reactor was studied. The reactor employed had a useful capacity of 9 l, operating at mesophilic temperature. Start-up of the reactor was carried out in different steps, beginning with diluted sludge and progressively increasing the amount of sludge fed into the reactor. The study was carried out over a period of 7 months. Different amounts of methanol were added to the feed, ranging between 6.75 and 1 cm{sup 3} dm{sup -3} of feed in order to favour the growth of methanogenic flora. The achieved biodegradation of the sludge using an upflow anaerobic sludge blanket Reactor was very high for an HRT of 9 days, obtaining decreases in COD of 84-87% by the end of the process. Purging of the digested sludge represented {approx}16% of the volume of the treated sludge.

  19. An activated sludge model based on activated sludge model number 3 for full-scale wastewater treatment plant simulation.

    PubMed

    Fan, Ji; Lu, Shu-Guang; Qiu, Zhao-fu; Wang, Xiao-Xia; Li, Wen-Zhen

    2009-06-01

    A modified model based on the activated sludge model no. 3 was established to simulate a full-scale municipal wastewater treatment plant in Shanghai, China. The activated sludge model no. 3 was modified to describe the simultaneous storage and growth processes occurring in activated sludge systems under aerobic and anoxic conditions. The mechanism of soluble microbial product formation and degradation by microorganisms was considered in this proposed model. Three months simulation was conducted including soluble chemical oxygen demand, NH4(+)-N, NO(X)(-)-N and T-N parameters, and compared with measured data from the Quyang wastewater treatment plant. Results indicated that the calculated effluent chemical oxygen demand and NH4(+)-N using this proposed model were in good agreement with the measured data. Results also showed that besides inert soluble organic matter contributing to the effluent chemical oxygen demand, soluble microbial products played an important part in the effluent chemical oxygen demand and, therefore, demonstrated that these products composed an important portion of effluent soluble chemical oxygen demand in wastewater treatment plants and should not be neglected.

  20. [Microbial composition of the activated sludges of the Moscow wastewater treatment plants].

    PubMed

    Kallistova, A Iu; Pimenov, N V; Kozlov, M N; Nikolaev, Iu A; Dorofeev, A G; Aseeva, V G; Grachev, V A; Men'ko, E V; Berestovskaia, Iu Iu; Nozhevnikova, A N; Kevbrina, M V

    2014-01-01

    The contribution of the major technologically important microbial groups (ammonium- and nitrite-oxidizing, phosphate-accumulating, foam-inducing, and anammox bacteria, as well as planctomycetes and methanogenic archaea) was characterized for the aeration tanks of the Moscow wastewater treatment facilities. FISH investigation revealed that aerobic sludges were eubacterial communities; the metabolically active archaea contributed insignificantly. Stage II nitrifying microorganisms and planctomycetes were significant constituents of the bacterial component of activated sludge, with Nitrobacter spp. being the dominant nitrifier. No metabolically active anammox bacteria were revealed in the sludge from aeration tanks. The sludge from the aeration tanks using different wastewater treatment technologies were found to differ in characteristics. Abundance of the nitrifying and phosphate-accumulating bacteria in the sludges generally correlated with microbial activity, in microcosms and with efficiency of nitrogen and phosphorus removal from wastewater. The highest microbial numbers and activity were found in the sludges of the tanks operating according to the technologies developed in the universities of Hanover and Cape Town. The activated sludge from the Novokur yanovo facilities, where abundant growth of filamentous bacteria resulted in foam formation, exhibited the lowest activity The group of foaming bacteria included Gordonia spp. and Acinetobacter spp., utilizing petroleum and motor oils, Sphaerotilus spp. utilizing unsaturated fatty acids, and Candidatus 'Microthrix parvicella'. Thus, the data on abundance and composition of metabolically active microorganisms obtained by FISH may be used for the technological control of wastewater treatment.

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

    SciTech Connect

    1995-01-01

    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.

  2. Ferric coagulant recovered from coagulation sludge and its recycle in chemically enhanced primary treatment.

    PubMed

    Xu, G R; Yan, Z C; Wang, N; Li, G B

    2009-01-01

    An investigation was conducted to study the feasibility of ferric coagulant recovery from chemical sludge and its recycle in chemically enhanced primary treatment (CEPT) to make the process more cost-effective, as well as reduce sludge volume. The optimum conditions and efficiency of the acidification for ferric coagulant recovery from coagulation sludge were investigated. Experimental results showed that the recovered coagulants can be used in CEPT and the pollutants removal efficiency is similar to that of fresh coagulant, and for some aspects the effect of recovered coagulants is better than that of fresh ones, such as turbidity removal. Although some substances will be enriched during recycle, they have little effect on treated wastewater quality. Acidification condition also had significant influence on reduction of sludge volume. The efficiency of coagulant recovery had a linear relationship with sludge reduction. Experiments verify that it would be a sustainable and cost-effective way to recover ferric coagulant from coagulation sludge in water treatment and chemical wastewater treatment, and then recycle it to CEPT, as well as reduce sludge volume.

  3. Sludge Conditioning. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Carnegie, John W.

    This lesson is an introduction to sludge conditioning. Topics covered include a brief explanation of colloidal systems, theory of chemical and heat conditioning, and conditioning aids. The lesson includes an instructor's guide and student workbook. The instructor's guide contains a description of the lesson, estimated presentation time,…

  4. Sludge Incineration. Multiple Hearth. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Klopping, Paul H.

    This lesson introduces the basics of sludge incineration and focuses on the multiple hearth furnace in accomplishing this task. Attention is given to component identification and function process control fundamentals, theory of incineration, safety, and other responsibilites of furnace operation. The material is rather technical and assumes an…

  5. Influence of ultrasonication and Fenton oxidation pre-treatment on rheological characteristics of wastewater sludge.

    PubMed

    Pham, T T H; Brar, S K; Tyagi, R D; Surampalli, R Y

    2010-01-01

    The effect of ultrasonication and Fenton oxidation as physico-chemical pre-treatment processes on the change of rheology of wastewater sludge was investigated in this study. Pre-treated and raw sludges displayed non-Newtonian rheological behaviour with shear thinning as well as thixotropic properties for total solids ranging from 10 g/L to 40 g/L. The rheological models, namely, Bingham plastic, Casson law, NCA/CMA Casson, IPC Paste, and power law were also studied to characterize flow of raw and pre-treated sludges. Among all rheological models, the power law was more prominent in describing the rheology of the sludges. Pre-treatment processes resulted in a decrease in pseudoplasticity of sludge due to the decrease in consistency index K varying from 42.4 to 1188, 25.6 to 620.4 and 52.5 to 317.9; and increase in flow behaviour index n changing from 0.5 to 0.35, 0.62 to 0.55 and 0.63 to 0.58, for RS, UlS and FS, respectively at solids concentration 10-40 g/L. The correlation between improvement of biodegradability and dewaterability, decrease in viscosity, and change in particle size as a function of sludge pre-treatment process was also investigated. Fenton oxidation facilitated sludge filterability resulting in capillary suction time values which were approximately 50% of the raw sludges, whereas ultrasonication with high input energy deteriorated the filterability. Biodegradability was also enhanced by the pre-treatment processes and the maximum value was obtained (64%, 77% and 73% for raw, ultrasonicated and Fenton oxidized sludges, respectively) at total solids concentration of 25 g/L. Hence, pre-treatment of wastewater sludge modified the rheological properties so that: (1) the flowability of sludge was improved for transport through the treatment train (via pipes and pumps); (2) the dewaterability of wastewater sludge was enhanced for eventual disposal and; (3) the assimilation of nutrients by microorganisms for further value-addition was increased.

  6. Combined System of Activated Sludge and Ozonation for the Treatment of Kraft E1 Effluent

    PubMed Central

    Assalin, Marcia Regina; dos Santos Almeida, Edna; Durán, Nelson

    2009-01-01

    The treatment of paper mill effluent for COD, TOC, total phenols and color removal was investigated using combined activated sludge-ozonation processes and single processes. The combined activated sludge-O3/pH 10 treatment was able to remove around 80% of COD, TOC and color from Kraft E1 effluent. For the total phenols, the efficiency removal was around 70%. The ozonation post treatment carried out at pH 8.3 also showed better results than the single process. The COD, TOC, color and total phenols removal efficiency obtained were 75.5, 59.1, 77 and 52.3%, respectively. The difference in the concentrations of free radical produced by activated sludge-O3/pH 10 and activated sludge-O3/pH 8.3 affected mainly the TOC and total phenol removal values. PMID:19440438

  7. Microwaving human faecal sludge as a viable sanitation technology option for treatment and value recovery - A critical review.

    PubMed

    Afolabi, Oluwasola O D; Sohail, M

    2017-02-01

    The prolonged challenges and terrible consequences of poor sanitation, especially in developing economies, call for the exploration of new sustainable sanitation technologies. Such technologies must be: capable of effectively treating human faecal wastes without any health or environmental impacts; scalable to address rapid increases in population and urbanization; capable of meeting environmental regulations and standards for faecal management; and competitive with existing strategies. Further and importantly, despite its noxiousness and pathogenic load, the chemical composition of human faecal sludge indicates that it could be considered a potentially valuable, nutrient-rich renewable resource, rather than a problematic waste product. New approaches to faecal sludge management must consequently seek to incorporate a 'valuable resource recovery' approach, compatible with stringent treatment requirements. This review intends to advance the understanding of human faecal sludge as a sustainable organic-rich resource that is typically high in moisture (up to 97 per cent), making it a suitable candidate for dielectric heating, i.e. microwave irradiation, to promote faecal treatment, while also recovering value-added products such as ammonia liquor concentrate (suitable for fertilizers) and chars (suitable for fuel) - which can provide an economic base to sustain the technology. Additionally, microwaving human faecal sludge represents a thermally effective approach that can destroy pathogens, eradicate the foul odour associated human faecal sludge, while also preventing hazardous product formations and/or emissions, aside from other benefits such as improved dewaterability and heavy metals recovery. Key technological parameters crucial for scaling the technology as a complementary solution to the challenges of onsite sanitation are also discussed.

  8. The use of fly ash and portland cement to chemically fix metal mine drainage treatment sludges

    SciTech Connect

    Hustwit, C.C.

    1996-11-01

    The conventional treatment of metal mine drainages produces a sludge consisting principally of metal hydroxides and oxides. There are no commonly used treatment technologies or methods to convert the metal hydroxides and oxides to more stable chemical forms. Industrial solid or semisolid wastes are often stabilized prior to final disposal with admixtures of fly ash, portland cement, or a combination of these materials. In this study, an adaptation of this stabilization method was evaluated for its ability to improve the settling rate, density, and chemical stability of a metal mine drainage treatment sludge. The corresponding properties of a hydrated lime-generated sludge were used as the basis of comparison. Hydrated lime is frequently used as a neutralizing reagent in mine drainage treatment. In this adaptation, the stabilizing materials were mixed with the mine drainage during treatment, rather than added to the sludge after treatment. There were two reasons for doing this. First, metal mine drainage treatment systems include mixers and their use for blending the stabilizing agent with the sludge during treatment would eliminate the need for separate mixing equipment. Second, the stabilizing agents tested were alkaline materials and may reduce the volume of hydrated lime required for treatment. Water treatment performance was also evaluated in this study.

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

    PubMed

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

    2012-10-15

    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.

  10. Long term in-line sludge storage in wastewater treatment plants: the potential for phosphorus release.

    PubMed

    Johannessen, Erik; Eikum, Arild Schanke; Krogstad, Tore

    2012-12-01

    Phosphorus removal in on-site wastewater treatment plants is normally obtained by chemical precipitation. Aluminium-based chemicals are the favoured coagulants as they are not affected by redox potential. On-site wastewater treatment package plants do not have separate sludge treatment facilities, and sludge is normally collected on an annual basis. This can potentially increase the risk of phosphorus release into the water phase, subsequently reducing treatment efficiency. This study aimed to detect release of phosphorus as a result of chemical and biological processes. Variables in the study were time, aluminium dosage and pH. Wastewater sludge was monitored for 46 weeks to investigate the different mechanisms of phosphorus release and the longevity of the aluminium treatment involving varying aluminium dosages. Phosphorus compounds were analysed based on a modified Psenner sequential fractionation method. Both pH and aluminium dosage affect the longevity of the phosphorus retention of chemically precipitated wastewater sludge, where sufficient longevity is obtained with pH control and increased aluminium dosages. Chemical dosages similar to what is considered normal levels are sufficient to retain the phosphorus in the sludge for annual sludge collection intervals. Release of soluble phosphorus was attributed to microbial activity and crystallization of Al-hydroxide complexes.

  11. SLUDGE TREATMENT PROJECT ALTERNATIVES ANALYSIS SUMMARY REPORT [VOLUME 1

    SciTech Connect

    FREDERICKSON JR; ROURK RJ; HONEYMAN JO; JOHNSON ME; RAYMOND RE

    2009-01-19

    Highly radioactive sludge (containing up to 300,000 curies of actinides and fission products) resulting from the storage of degraded spent nuclear fuel is currently stored in temporary containers located in the 105-K West storage basin near the Columbia River. The background, history, and known characteristics of this sludge are discussed in Section 2 of this report. There are many compelling reasons to remove this sludge from the K-Basin. These reasons are discussed in detail in Section1, and they include the following: (1) Reduce the risk to the public (from a potential release of highly radioactive material as fine respirable particles by airborne or waterborn pathways); (2) Reduce the risk overall to the Hanford worker; and (3) Reduce the risk to the environment (the K-Basin is situated above a hazardous chemical contaminant plume and hinders remediation of the plume until the sludge is removed). The DOE-RL has stated that a key DOE objective is to remove the sludge from the K-West Basin and River Corridor as soon as possible, which will reduce risks to the environment, allow for remediation of contaminated areas underlying the basins, and support closure of the 100-KR-4 operable unit. The environmental and nuclear safety risks associated with this sludge have resulted in multiple legal and regulatory remedial action decisions, plans,and commitments that are summarized in Table ES-1 and discussed in more detail in Volume 2, Section 9.

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

    PubMed

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

    2014-06-01

    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.

  13. Influence of microwave pre-treatment on sludge solubilization and pilot scale semi-continuous anaerobic digestion.

    PubMed

    Appels, Lise; Houtmeyers, Sofie; Degrève, Jan; Van Impe, Jan; Dewil, Raf

    2013-01-01

    Anaerobic digestion is widely applied for the recovery of energy from waste activated sludge. Pre-treatment methods are of high interest to increase the biodegradability of the sludge and to enhance the digestion efficiency. This paper studies the application of a microwave pre-treatment. An experimental set-up of two pilot scale semi-continuous digesters was used. During a long term experiment, one of the reactors was fed with untreated sludge, while microwave pre-treated sludge (336 kJ/kg sludge) was introduced in the second one. A solid retention time of 20 days was kept during the experiments. (Organic) dry solids, carbohydrates, proteins and volatile fatty acids were monitored during digestion. It was seen that the microwave pre-treatment resulted in an effective solubilization of the organic matter in the sludge. The changes to the sludge composition resulted in an increase in biogas production by 50%, while the methane concentration in both reactors remained stable.

  14. Achalasia: advances in treatment.

    PubMed

    Schoenberg, Markus Bo; Vassiliou, Melina Catherine; von Renteln, Daniel

    2014-09-01

    Achalasia is a primary esophageal motility disorder, which shows distinct clinical, manometric, radiologic, and pathologic features. Available treatment strategies are pharmacological, endoscopic or surgical. In the past decades preferred treatment has alternated between surgical myotomy (presently Laparoscopic Heller Myotomy [LHM]) and endoscopic balloon dilation (EBD). While surgical myotomy promises superior long-term results and significantly less retreatment, endoscopic balloon dilation is initially far less invasive and yields comparable results after redilation. Peroral Endoscopic Myotomy (POEM) aims to combine the minimal invasive approach through the mouth with the better long-term results after LHM. Initial findings in the literature point to comparable success-rates after POEM and LHM. In the literature complication rates are similar to those obtained after surgery. This new interventional technique should be subject to randomized controlled trials and compared to EBD and LHM.

  15. Biological treatment of sewage treatment plant sludge by pure bacterial culture with optimum process conditions in a stirred tank bioreactor.

    PubMed

    Alam, M Z; Muyibi, Suleyman A; Jamal, P

    2007-09-01

    Biological treatment of sewage treatment plant (STP) sludge by potential pure bacterial culture (Bacillus sp.) with optimum process conditions for effective biodegradation and bioseparation was carried out in the laboratory. The effective and efficient bioconversion was evaluated with the treatment of pure bacterial culture and existing microbes (uninnoculated) in sludge. The optimum process conditions i.e., temperature, 40 degrees C; pH, 6; inoculum, 5% (v/v); aeration, 1 vvm; agitation speed, 50 rpm obtained from the previous studies with chemical oxygen demand COD at 30 mgL(-1) were applied for the biological treatment of sludge. The results indicated that pure bacterial culture (Bacillus sp.) showed higher degradation and separation of treated sludge compared to treatment with the existing mixed microbes in a stirred tank bioreactor. The treated STP sludge by potential pure bacterial culture and existing microbes gave 30% and 11%; 91.2% and 59.1; 88.5% and 52.3%; 98.4% and 51.3%; 96.1% and 75.2%; 99.4% and 72.8% reduction of total suspended solids (TSS, biosolids), COD, soluble protein, turbidity, total dissolved solids (TDS) and specific resistance to filtration (SRF), respectively within 7 days of treatment. The pH was observed at 6.5 and 4 during the treatment of sludge by pure culture and existing microbes, respectively.

  16. Helminth ova control in wastewater and sludge for advanced and conventional sanitation.

    PubMed

    Jiménez, B; Maya, C; Galván, M

    2007-01-01

    Worldwide, the most important reuse of wastewater, in volume, is agricultural irrigation. Therefore, there is a need to properly treat wastewater for such purpose, considering the removal of pathogens while leaving suitable amounts of nutrients and other compounds to increase productivity. Helminth ova are one of the main targeted pathogens in the new guidelines for water reuse in agriculture and aquaculture issued in 2006 by the World Health Organization. However, relatively little research has been done recently on how to remove and inactivate helminth ova from wastewater and sludge and recommendations given several decades ago are still used, but when put into practice, particularly in developing countries, produce unsatisfactory results. One problem is that these criteria were developed using inaccurate analytical techniques and the other is the large number and variety of helminth ova species found in wastewater and sludge from the developing world. In fact, the few technological options to remove and inactivate helminth ova come from research performed using wastewater and sludge with low helminth ova content, and refer almost only to Ascaris (one type of helminth). This paper summarises recent research work and results from practical experience concerning helminth ova control for advanced and conventional sanitation.

  17. Effect of lime addition during sewage sludge treatment on characteristics of resulting SSA when it is used in cementitious materials.

    PubMed

    Vouk, D; Nakic, D; Štirmer, N; Baricevic, A

    2017-02-01

    Final disposal of sewage sludge is important not only in terms of satisfying the regulations, but the aspect of choosing the optimal wastewater treatment technology, including the sludge treatment. In most EU countries, significant amounts of stabilized and dewatered sludge are incinerated, and sewage sludge ash (SSA) is generated as a by product. At the same time, lime is one of the commonly used additives in the sewage sludge treatment primarily to stabilize the sludge. In doing so, the question arose how desirable is such addition of lime if the sludge is subsequently incinerated, and the generated ash is further used in the production of cementitious materials. A series of mortars were prepared where 10-20% of the cement fraction was replaced by SSA. Since all three types of analyzed SSA (without lime, with lime added during sludge stabilization and with extra lime added during sludge incineration) yielded nearly same results, it can be concluded that if sludge incineration is accepted solution, lime addition during sludge treatment is unnecessary even from the standpoint of preserving the pozzolanic properties of the resulting SSA. Results of the research carried out on cement mortars point to the great possibilities of using SSA in concrete industry.

  18. Production of biodegradable plastics from activated sludge generated from a food processing industrial wastewater treatment plant.

    PubMed

    Suresh Kumar, M; Mudliar, S N; Reddy, K M K; Chakrabarti, T

    2004-12-01

    Most of the excess sludge from a wastewater treatment plant (60%) is disposed by landfill. As a resource utilization of excess sludge, the production of biodegradable plastics using the sludge has been proposed. Storage polymers in bacterial cells can be extracted and used as biodegradable plastics. However, widespread applications have been limited by high production cost. In the present study, activated sludge bacteria in a conventional wastewater treatment system were induced, by controlling the carbon: nitrogen ratio to accumulate storage polymers. Polymer yield increased to a maximum 33% of biomass (w/w) when the C/N ratio was increased from 24 to 144, where as specific growth yield decreased with increasing C/N ratio. The conditions which are required for the maximum polymer accumulation were optimized and are discussed.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  20. Nitrification and Heavy Metal Removal in the Activated Sludge Treatment Process.

    DTIC Science & Technology

    1976-08-01

    parameters to heavy metal removal in the activated sludge waste treatment process. The heavy metals studied were chromium and silver. Analyses...performed on the influent, mixed liquor, return sludge, and effluent included heavy metal concentration, pH, dissolved oxygen, temperature, suspended solids...related to heavy metal removal. Nitrification is only indirectly related. A theory for the mechanisms contributing to heavy metal removal is developed.

  1. Coagulant recovery from water treatment plant sludge and reuse in post-treatment of UASB reactor effluent treating municipal wastewater.

    PubMed

    Nair, Abhilash T; Ahammed, M Mansoor

    2014-09-01

    In the present study, feasibility of recovering the coagulant from water treatment plant sludge with sulphuric acid and reusing it in post-treatment of upflow anaerobic sludge blanket (UASB) reactor effluent treating municipal wastewater were studied. The optimum conditions for coagulant recovery from water treatment plant sludge were investigated using response surface methodology (RSM). Sludge obtained from plants that use polyaluminium chloride (PACl) and alum coagulant was utilised for the study. Effect of three variables, pH, solid content and mixing time was studied using a Box-Behnken statistical experimental design. RSM model was developed based on the experimental aluminium recovery, and the response plots were developed. Results of the study showed significant effects of all the three variables and their interactions in the recovery process. The optimum aluminium recovery of 73.26 and 62.73 % from PACl sludge and alum sludge, respectively, was obtained at pH of 2.0, solid content of 0.5 % and mixing time of 30 min. The recovered coagulant solution had elevated concentrations of certain metals and chemical oxygen demand (COD) which raised concern about its reuse potential in water treatment. Hence, the coagulant recovered from PACl sludge was reused as coagulant for post-treatment of UASB reactor effluent treating municipal wastewater. The recovered coagulant gave 71 % COD, 80 % turbidity, 89 % phosphate, 77 % suspended solids and 99.5 % total coliform removal at 25 mg Al/L. Fresh PACl also gave similar performance but at higher dose of 40 mg Al/L. The results suggest that coagulant can be recovered from water treatment plant sludge and can be used to treat UASB reactor effluent treating municipal wastewater which can reduce the consumption of fresh coagulant in wastewater treatment.

  2. Metaproteomics Provides Functional Insight into Activated Sludge Wastewater Treatment

    PubMed Central

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

    2008-01-01

    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 α-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 β 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

  3. Parasite contamination (helminth eggs) in sludge treatment plants: definition of a sampling strategy.

    PubMed

    Gaspard, Philippe G; Schwartzbrod, Janine

    2003-03-01

    The use of sludge in agriculture must be carried out according to many guidelines, especially regarding a precise knowledge of the pathogenic microorganisms it contains. The control of the produced sludge requires a sampling strategy that is representative of the contamination present in the sludge. Thus, we evaluated the distribution of helminth eggs in sludge to determine how to sample and at what frequency. Two plants were studied, firstly we studied sludge that was undergoing biological treatment (anaerobic digestion, prolonged aeration), secondly we evaluated the dehydration step (centrifugation and filter press). The helminth egg concentrations were measured over short periods (between 5 minutes and 7 hours) and for periods of over 24 hours (7 to 28 days). The results showed that there was much homogeneity in periods of less than 7 hours, thus it was advisable to take grab samples. An appropriate sample weight was 30 g dry matter, because this allowed an analysis in triplicate when testing treatment processes according to standards of France, (less than 3 viable eggs/10 g dry matter). Determination of the egg concentration in the plants during periods of over 24 hours showed that the parasite flow was stable. In some cases, large variations were due to the treatment processes (storage or thickening, mixing of different sludges). These results have been confirmed with the study of 6 other plants during a one year period. Thus, the recommended sampling frequency can be limited to every 3 to 6 months, by adapting the sampling methods to the characteristics of the plant.

  4. Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

    PubMed

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2006-11-02

    The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

  5. Sludge population optimisation: a new dimension for the control of biological wastewater treatment systems.

    PubMed

    Yuan, Zhiguo; Blackall, Linda L

    2002-01-01

    The activated sludge comprises a complex microbiological community. The structure (what types of microorganisms are present) and function (what can the organisms do and at what rates) of this community are determined by external physico-chemical features and by the influent to the sewage treatment plant. The external features we can manipulate but rarely the influent. Conventional control and operational strategies optimise activated sludge processes more as a chemical system than as a biological one. While optimising the process in a short time period, these strategies may deteriorate the long-term performance of the process due to their potentially adverse impact on the microbial properties. Through briefly reviewing the evidence available in the literature that plant design and operation affect both the structure and function of the microbial community in activated sludge, we propose to add sludge population optimisation as a new dimension to the control of biological wastewater treatment systems. We stress that optimising the microbial community structure and property should be an explicit aim for the design and operation of a treatment plant. The major limitations to sludge population optimisation revolve around inadequate microbiological data, specifically community structure, function and kinetic data. However, molecular microbiological methods that strive to provide that data are being developed rapidly. The combination of these methods with the conventional approaches for kinetic study is briefly discussed. The most pressing research questions pertaining to sludge population optimisation are outlined.

  6. Use of acid preconditioning for enhanced dewatering of wastewater treatment sludges from the pulp and paper industry.

    PubMed

    Mahmood, Talat; Elliott, Allan

    2007-02-01

    In municipal and industrial practices, wastewater treatment sludges are generally conditioned with organic polymers before dewatering. The dewatering polymers are expensive and contribute significantly to the overall sludge management cost. This paper discusses a preconditioning strategy that holds great promise for enhancing dewatering properties of wastewater treatment sludges, while reducing the cost. In this approach, the waste activated sludge (WAS) is briefly preconditioned with an acid before flocculating with an organic polymer. Experimental results showed that acid preconditioning significantly enhanced dewatering. Separately acidifying WAS and subsequently combining it with primary sludge produced higher presscake solids than acidifying the combined sludge to the same final pH. Acidification exhibited the added benefit of reducing Escherichia coli counts in sludge, thus improving its biological character. This may provide flexibility in choosing a beneficial use application.

  7. PAH removal from spiked municipal wastewater sewage sludge using biological, chemical and electrochemical treatments.

    PubMed

    Zheng, Xue-Jing; Blais, Jean-François; Mercier, Guy; Bergeron, Mario; Drogui, Patrick

    2007-06-01

    Polycyclic aromatic hydrocarbons (PAHs) have been widely studied due to their presence in all the environmental media and toxicity to life. These molecules are strongly adsorbed on the particulate matters of soils, sludges or sediments because of their strong hydrophobicity which makes them less bioavailability, thus limiting their bioremediation. Different sludge treatment processes were tested to evaluate their performances for PAH removal from sludge prealably doped with 11 PAHs (5.5mg each PAH kg(-1) of dry matter (DM)): two biological processes (mesophilic aerobic digestion (MAD) and simultaneous sewage sludge digestion and metal leaching (METIX-BS)) were tested to evaluate PAH biodegradation in sewage sludge. In parallel, two chemical processes (quite similar Fenton processes: chemical metal leaching (METIX-AC) and chemical stabilization (STABIOX)) and one electrochemical process (electrochemical stabilization (ELECSTAB)) were tested to measure PAH removal by these oxidative processes. Moreover, PAH solubilisation from sludge by addition of a nonionic surfactant Tween 80 (Tw80) was also tested. The best yields of PAH removal were obtained by MAD and METIX-BS with more than 95% 3-ring PAH removal after a 21-day treatment period. Tw80 addition during MAD treatment increased 4-ring PAHs removal rate. In addition, more than 45% of 3-ring PAHs were removed from sludge by METIX-AC and during ELECSTAB process were quiet good with approximately 62% of 3-ring PAHs removal. However, little weaker removal of 3-ring PAHs (<35%) by STABIOX. None of the tested processes were efficient for the elimination of high molecular weight (> or = 5-ring) PAHs from sludge.

  8. Improvement of anaerobic digestion of sewage sludge through microwave pre-treatment.

    PubMed

    Serrano, A; Siles, J A; Martín, M A; Chica, A F; Estévez-Pastor, F S; Toro-Baptista, E

    2016-07-15

    Sewage sludge generated in the activated sludge process is a polluting waste that must be treated adequately to avoid important environmental impacts. Traditional management methods, such as landfill disposal or incineration, are being ruled out due to the high content in heavy metal, pathogens, micropolluting compounds of the sewage sludge and the lack of use of resources. Anaerobic digestion could be an interesting treatment, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A microwave pre-treatment at pilot scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. The operational variables of microwave pre-treatment (power and specific energy applied) were optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) under different pre-treatment conditions. According to the variation in the sCOD and TN concentration, the optimal operation variables of the pre-treatment were fixed at 20,000 J/g TS and 700 W. A subsequent anaerobic digestion test was carried out with raw and pre-treated sewage sludge under different conditions (20,000 J/g TS and 700 W; 20,000 J/g TS and 400 W; and 30,000 J/g TS and 400 W). Although stability was maintained throughout the process, the enhancement in the total methane yield was not high (up to 17%). Nevertheless, very promising improvements were determined for the kinetics of the process, where the rG and the OLR increased by 43% and 39%, respectively, after carrying out a pre-treatment at 20,000 J/g TS and 700 W.

  9. Enhancing post anaerobic digestion of full-scale anaerobically digested sludge using free nitrous acid treatment.

    PubMed

    Zhang, Tingting; Wang, Qilin; Ye, Liu; Yuan, Zhiguo

    2016-05-01

    In some wastewater treatment plants (WWTPs), the ever increasing production of sludge with the expanding population overloaded the anaerobic digestion which compromises the sludge reduction efficiency. Post anaerobic digestion of anaerobically digested sludge (ADS) has been applied to enhance sludge reduction, however, to a very limited extent. This study verified the effectiveness of free nitrous acid (FNA i.e. HNO2) pre-treatment on enhancing full-scale ADS degradation in post anaerobic digestion. The ADS collected from a full-scale WWTP was subject to FNA treatment at concentrations of 0.77, 1.54, 2.31, 3.08, and 3.85 mg N/L for 24 h followed by biochemical methane potential tests. The FNA treatment at all concentrations resulted in an increase (from 1.5-3.1 % compared to the control) in sludge reduction with the highest improvement achieved at 0.77 mg HNO2-N/L. The FNA treatment at this concentration also resulted in the highest increase in methane production (40 %) compared to the control. The economic analysis indicates that FNA treatment is economically attractive for enhancing post anaerobic digestion of full-scale ADS.

  10. [Diversity of culturable filamentous bacteria in the activated sludge from A2O wastewater treatment process].

    PubMed

    Gao, Sha; Jin, De-Cai; Zhao, Zhi-Rui; Qi, Rong; Peng, Xia-Wei; Bai, Zhi-Hui

    2013-07-01

    The anoxic-anaerobic-oxic (A2O) process is widely used in wastewater treatment plant, however, sludge bulking and foaming are the most frequent operational problems in this process. Activated sludge bulking is caused by the overgrowth of some types of filamentous bacteria, especially Microthrix parvicella. In the study, 17 strains of filamentous bacteria were isolated from the bulking sludge of A2O process using Gause's medium. The 16S rRNA genes of the 17 isolates were sequenced to analyze their diversity. The results showed all of the 17 isolates were Streptomyces. Further analysis of these strains by the repetitive sequence based on polymerase chain reaction (rep-PCR) technology showed that there was a high diversity in these isolated Streptomyces. The physiological properties of them were different from Microthrix parvicella. The settleability of activated sludge was improved when some of the isolates were inoculated.

  11. Effect of water treatment sludge on growth and elemental composition of tomato (Lycopersicon esculentum) shoots

    SciTech Connect

    Elliott, H.A.; Singer, L.M. )

    1988-01-01

    The impact of a water treatment sludge on the fertility of a silt loam soil was assessed by monitoring the yield and elemental composition of tomato (Lycopersicon esculentum) shoots in a greenhouse study. Application of sludge at rates from 2-10% (air dry weight basis) raised the soil pH from 5.3 to 8.0 which enhanced plant growth. A substantial reduction in metal (Cd, Zn, Cu, Ni) uptake was observed with sludge amendments, even at the highest rates. The alkaline nature of this sludge (pH=9.3, calcium carbonate equivalence=53%) suggest its potential use as a liming material for agricultural soils. Overly alkaline conditions should be avoided however, as high application rates combined with ammonia fertilization had an antagonistic effect on plant growth, possibly from P deficiency induced by struvite (MgNH{sub 4}PO{sub 4}) formation.

  12. Study on sludge expansion during treatment of salad oil manufacturing wastewater by yeast.

    PubMed

    Zheng, S; Yang, M; Lv, W; Liu, F

    2001-05-01

    Five yeast strains, namely Rhodotorula rubra, Candida tropicalis, Candida utilis, Candida boidinii, Trichosporon cutaneum, were isolated from soil spots of a salad oil factory, and applied for continuous treatment of salad oil manufacturing wastewater. The oil and COD removal performance of the mixed cultures were comparable to the results other researchers obtained. Sludge expansion, accompanied with sludge morphology change from pseudomycelia to true mycelia, occurred during continuous treatment of wastewater. The true mycelia dominated sludge had a much higher water content and SVI value than that of the yeast pure cultures, although the two kinds of sludge had similar oil removal performance. A mold, Geotrichum candidum, was isolated from the expanded sludge, and was suspected to be a reason for sludge expansion. Addition of 0.3% sodium propionate into batch cultures degraded SVI value from around 100 to 60. In a continuous running, addition of 10 mg l-1 sodium hypochlorite decreased SVI value from over 200 to below 100. The yeast activity, however, was weakened to a large extent at the same time.

  13. Sludge-Drying Lagoons: a Potential Significant Methane Source in Wastewater Treatment Plants.

    PubMed

    Pan, Yuting; Ye, Liu; van den Akker, Ben; Ganigué Pagès, Ramon; Musenze, Ronald S; Yuan, Zhiguo

    2016-02-02

    "Sludge-drying lagoons" are a preferred sludge treatment and drying method in tropical and subtropical areas due to the low construction and operational costs. However, this method may be a potential significant source of methane (CH4) because some of the organic matter would be microbially metabolized under anaerobic conditions in the lagoon. The quantification of CH4 emissions from lagoons is difficult due to the expected temporal and spatial variations over a lagoon maturing cycle of several years. Sporadic ebullition of CH4, which cannot be easily quantified by conventional methods such as floating hoods, is also expected. In this study, a novel method based on mass balances was developed to estimate the CH4 emissions and was applied to a full-scale sludge-drying lagoon over a three year operational cycle. The results revealed that processes in a sludge-drying lagoon would emit 6.5 kg CO2-e per megaliter of treated sewage. This would represent a quarter to two-thirds of the overall greenhouse gas (GHG) emissions from wastewater-treatment plants (WWTPs). This work highlights the fact that sludge-drying lagoons are a significant source of CH4 that adds substantially to the overall GHG footprint of WWTPs despite being recognized as a cheap and energy-efficient means of drying sludge.

  14. Concentrations of trace substances in sewage sludge from 28 wastewater treatment works in the UK.

    PubMed

    Jones, Vera; Gardner, Mike; Ellor, Brian

    2014-09-01

    Concentrations of trace substances in sewage sludge have been measured in a survey of 28 wastewater treatment works (WwTWs) in the UK carried out over a period of 12months. Approximately 250 samples were analysed for more than 40 trace contaminants, including trace metals, pharmaceuticals, polycyclic aromatic hydrocarbons (PAHs), 'emerging' and regulated organic pollutants. All substances investigated were found to be present in at least some of the sludges sampled. Concentrations were relatively homogenous across all the WwTWs, irrespective of the treatment process, influent and effluent concentrations, and the location of the sludge sampling point within each works. Analysis of the results against existing regulatory and proposed thresholds suggested that levels are mostly below the limits set in the Sewage Sludge Directive, and proposed new limits for sludge used in agriculture. Predicted soil concentrations after application of sewage sludge to land were below the predicted no effect concentrations (PNEC) for all determinands. Predicted concentrations of pharmaceuticals in soil were also below thresholds deemed to indicate negligible environmental risk.

  15. Engineering properties of water/wastewater-treatment sludge modified by hydrated lime, fly ash and loess.

    PubMed

    Lim, Sungjin; Jeon, Wangi; Lee, Jaebok; Lee, Kwanho; Kim, Namho

    2002-10-01

    The purpose of this research was to present engineering properties of modified sludge from water/wastewater treatment by modifiers such as hydrated lime, loess, and fly ash. The proper mixing ratio was determined to hold the pH of the modified sludge above 12.0 for 2 h. Laboratory tests carried out in this research included particle analysis, compaction and CBR, SEM and X-ray diffraction, unconfined compression test, permeability test, and TCLP test. The main role of lime was to sterilize microorganisms in the sludge. The unconfined strength of the modified sludge by fly ash and loess satisfied the criteria for construction materials, which was above 100 kPa. The permeability of all the mixtures was around 1.0 x 10(-7) cm/s. Extraction tests for hazardous components in modified sludge revealed below the regulated criteria, especially for cadmium, copper, and lead. The present study suggested that the use of lime, fly ash, and loess be an another alternative to modify or stabilize water/wastewater treatment sludge as construction materials in civil engineering.

  16. Image analysis of sludge aggregates obtained at preliminary treatment of sewage.

    PubMed

    Smoczyński, L; Ratnaweera, H; Kosobucka, M; Kvaal, K; Smoczyński, M

    2014-01-01

    The results of wastewater treatment by Al and Fe salts and by electrocoagulation with aluminum electrodes are discussed and interpreted. Those processes used alone or combined with biological treatment, were analyzed for 50 and 90% removal of phosphates. Scanning electron microscopy (SEM) of the resulting sludge from three coagulation processes defined the perimeter P and area A of 129-142 differently sized objects in each contrast-enhanced image. Plots of lg A against lg P revealed that the analyzed sludge samples were made of self-similar aggregates-flocs with fractal characteristics. The slope of 'log plots' was used to determine surface fractal dimension Da, which was extrapolated to volumetric fractal dimension Dv. Dv was applied in a quantitative description of sludge aggregates-flocs. Aggregates-flocs of sludge obtained by Al ions (pre-polymerized Al and electrocoagulation) were characterized by higher values of Dv in comparison with sludge obtained by iron salts. The structure of {Al(OH)(3)} and {Fe(OH)(3)} aggregate-flocs was graphically simulated to determine the effect of size distribution and Dv on sweep flocculation and sludge separation and dehydration. Phosphate removal efficiency of 50% occurred at low ratios of Al:P and Fe:P. Adsorption-charge neutralization was suggested during coagulation with pre-polymerized coagulants, and sweep flow mechanism during electrocoagulation.

  17. Biological denitrification of brines from membrane treatment processes using an upflow sludge blanket (USB) reactor.

    PubMed

    Beliavski, M; Meerovich, I; Tarre, S; Green, M

    2010-01-01

    This paper investigates denitrification of brines originating from membrane treatment of groundwater in an upflow sludge blanket (USB) reactor, a biofilm reactor without carrier. A simulated brine wastewater was prepared from tap water and contained a nitrate concentration of 125 mg/l as N and a total salt concentration of about 1%. In order to select for a suitable energy source for denitrification, two electron donors were compared: one promoting precipitation of calcium compounds (ethanol), while the other (acetic acid), no precipitation was expected. After extended operation to reach steady state, the sludge from the two reactors showed very different mineral contents. The VSS/TSS ratio in the ethanol fed reactor was 0.2, i.e., 80% mineral content, while the VSS/TSS ratio in the acetic acid fed reactor was 0.9, i.e., 10% mineral content. In spite of the low mineral content, the sludge from the acetic acid fed reactor showed remarkably excellent granulation and settling characteristics. Although the denitrification performance of the acetic acid fed reactor was similar to that of the ethanol fed reactor, there was a huge difference in the sludge production due to mineral precipitation, with the corresponding negative aspects including increased costs of sludge treatment and disposal and moreover, instability and difficulties in reactor operation (channeling). These arguments make acetic acid a much more suitable candidate for brine denitrification, despite previous findings observed in groundwater denitrification regarding the essential role of a relatively high sludge mineral fraction for stable and effective USB reactor operation. Based on a comparison between two denitrification reactors with and without salt addition and using acetic acid as the electron donor, it was concluded that the reason for the excellent sludge settling characteristics found in the acetic acid fed reactor is the positive effects of higher salinity on granular sludge formation.

  18. Adsorption of textile reactive dyestuffs by treatment sludges of inorganic nature.

    PubMed

    Tünay, Olcay; Metin, Emine; Olmez-Hanci, Tuğba; Kabdaşli, Işik

    2012-01-01

    Colour removal from industrial effluents, particularly from the textile industry, has become an important requirement as the adverse effects ofdyestuffs, such as toxicity, on the environment have been proven. Adsorption is a commonly used treatment method for colour removal. Although activated carbon is very effective for this purpose, a number of natural materials and waste materials, such as waste sludges generated from treatment systems, have been tested to reduce the cost of the process. In this paper, sludges arising from the operation of an electrocoagulation process that used stainless steel or aluminium electrodes were investigated as adsorbents for decolorization of reactive dyestuffs. Electrocoagulation waste sludges produced with the use of stainless steel electrodes provided higher than 90% or complete decolorization of Crimson HEXL, Yellow HE4R and RB5 dyestuffs. The sludge produced with aluminium electrodes yielded colour adsorption between 95% and 100% at a 1 g/L dose and pH 8.5-9.1 for two of the dyestuffs; the removal of RB5 did not exceed 60% up to a 4.76 g/L dose. FeCl3 coagulation and adsorption using freshly precipitated coagulation sludge resulted in poor colour removals of 10% for all three dyestuffs. The superior colour adsorption performance of electrocoagulation waste sludges was attributed to modification of the surface properties of the sludges during the electrocoagulation operation. A batch-wise kinetic study indicated that the adsorption of RB5 on to electrocoagulation waste sludges was well fitted by the pseudo-second-order kinetic model, suggesting the intra-particle diffusion process as the rate-limiting step of the adsorption process.

  19. Determination of the acute toxicities of physicochemical pretreatment and advanced oxidation processes applied to dairy effluents on activated sludge.

    PubMed

    Sivrioğlu, Özge; Yonar, Taner

    2015-04-01

    In this study, the acute toxicities of raw, physicochemical pre-treated, ozonated, and Fenton reagent applied samples of dairy wastewater toward activated sludge microorganisms, evaluated using the International Organization for Standardization's respiration inhibition test (ISO 8192), are presented. Five-day biological oxygen demand (BOD5) was measured to determine the biodegradability of physicochemical treatment, ozonation, Fenton oxidation or no treatment (raw samples) of dairy wastewater. Chemical pretreatment positively affected biodegradability, and the inhibition exhibited by activated sludge was removed to a considerable degree. Ozonation and the Fenton process exhibited good chemical oxygen demand removal (61%) and removal of toxins. Low sludge production was observed for the Fenton process applied to dairy effluents. We did not determine the inhibitory effect of the Fenton-process on the activated sludge mixture. The pollutant-removal efficiencies of the applied processes and their associated operating costs were determined.

  20. Disinfection of sludge using lime stabilisation and pasteurisation in a small wastewater treatment plant.

    PubMed

    Keller, R; Passamani-Franca, R F; Cassini, S T; Gonçalves, F R

    2004-01-01

    Removal efficiency of faecal coliforms and helminth eggs was evaluated in a small wastewater treatment plant (WWTP) serving a population of 1,000. This system was formed by the association in series of a UASB reactor and four submerged aerated biofilters. The density of faecal coliforms and the count of helminth eggs were estimated in the liquid and solid phases of the system. Two different methods of disinfecting sludge were investigated: (a) chemical treatment with lime and (b) a physical treatment by pasteurisation. As expected, the association UASB + BF was very efficient at removal of helminth eggs from the final tertiary effluent, but coliforms were still present at high densities. Lime treatment and pasteurisation of sludge were very effective methods of disinfection and produced a sludge safe for final disposal.

  1. Activated Sludge. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Boe, Owen K.

    This instructor's guide contains the materials needed to teach a seven-lesson unit on activated sludge. These materials include an overview of the unit, lesson plans, lecture outlines (keyed to slides designed for use with the lessons), student worksheets for each of the seven lessons (with answers), and two copies of a final quiz (with and…

  2. Investigation of sewage sludge treatment using air plasma assisted gasification.

    PubMed

    Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis

    2017-03-18

    This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power.

  3. Lifecycle analysis of renewable natural gas and hydrocarbon fuels from wastewater treatment plants’ sludge

    SciTech Connect

    Lee, Uisung; Han, Jeongwoo; Urgun Demirtas, Meltem; Wang, Michael; Tao, Ling

    2016-09-01

    Wastewater treatment plants (WWTPs) produce sludge as a byproduct when they treat wastewater. In the United States, over 8 million dry tons of sludge are produced annually just from publicly owned WWTPs. Sludge is commonly treated in anaerobic digesters, which generate biogas; the biogas is then largely flared to reduce emissions of methane, a potent greenhouse gas. Because sludge is quite homogeneous and has a high energy content, it is a good potential feedstock for other conversion processes that make biofuels, bioproducts, and power. For example, biogas from anaerobic digesters can be used to generate renewable natural gas (RNG), which can be further processed to produce compressed natural gas (CNG) and liquefied natural gas (LNG). Sludge can be directly converted into hydrocarbon liquid fuels via thermochemical processes such as hydrothermal liquefaction (HTL). Currently, the environmental impacts of converting sludge into energy are largely unknown, and only a few studies have focused on the environmental impacts of RNG produced from existing anaerobic digesters. As biofuels from sludge generate high interest, however, existing anaerobic digesters could be upgraded to technology with more economic potential and more environmental benefits. The environmental impacts of using a different anaerobic digestion (AD) technology to convert sludge into energy have yet to be analyzed. In addition, no studies are available about the direct conversion of sludge into liquid fuels. In order to estimate the energy consumption and greenhouse gas (GHG) emissions impacts of these alternative pathways (sludge-to-RNG and sludge-to-liquid), this study performed a lifecycle analysis (LCA) using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model. The energy uses and GHG emissions associated with the RNG and hydrocarbon liquid are analyzed relative to the current typical sludge management case, which consists of a single-stage mesophilic

  4. Oak Ridge National Laboratory West End Treatment Facility simulated sludge vitrification demonstration, Revision 1

    SciTech Connect

    Cicero, C.A.; Bickford, D.F.; Bennert, D.M.; Overcamp, T.J.

    1994-01-26

    Technologies are being developed by the US Department of Energy`s (DOE) Nuclear Facility sites to convert hazardous and mixed wastes to a form suitable for permanent disposal. Vitrification, which has been declared the Best Demonstrated Available Technology for high-level radioactive waste disposal by the EPA, is capable of producing a highly durable wasteform that minimizes disposal volumes through organic destruction, moisture evaporation, and porosity reduction. However, this technology must be demonstrated over a range of waste characteristics, including compositions, chemistries, moistures, and physical characteristics to ensure that it is suitable for hazardous and mixed waste treatment. These wastes are typically wastewater treatment sludges that are categorized as listed wastes due to the process origin or organic solvent content, and usually contain only small amounts of hazardous constituents. The Oak Ridge National Laboratory`s (ORNL) West End Treatment Facility`s (WETF) sludge is considered on of these representative wastes. The WETF is a liquid waste processing plant that generates sludge from the biodenitrification and precipitation processes. An alternative wasteform is needed since the waste is currently stored in epoxy coated carbon steel tanks, which have a limited life. Since this waste has characteristics that make it suitable for vitrification with a high likelihood of success, it was identified as a suitable candidate by the Mixed Waste Integrated Program (MWIP) for testing at CU. The areas of special interest with this sludge are (1) minimum nitrates, (2) organic destruction, and (3) waste water treatment sludges containing little or no filter aid.

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

    PubMed

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

    2014-07-01

    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.

  6. Evaluation of the improvement of sonication pre-treatment in the anaerobic digestion of sewage sludge.

    PubMed

    Martín, María Ángeles; González, Inmaculada; Serrano, Antonio; Siles, José Ángel

    2015-01-01

    Sewage sludge is a polluting and hazardous waste generated in wastewater treatment plants with severe management problems. The high content in heavy metal, pathogens and micropolluting compounds limit the implementation of the available management methods. Anaerobic digestion could be an interesting treatment method, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A sonication pre-treatment at lab scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. Sonication time was optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) at different pre-treatment times. The pre-treatment time was fixed at 45 min under the study conditions given that the solubilisation of organic matter did not increase significantly at lower sonication times, whereas the concentration of total nitrogen increased markedly at higher times. The volatile fatty acids generation rate was also evaluated for the pre-treatment conditions. The anaerobic digestion of untreated and pre-treated sewage sludge was subsequently compared and promising results were obtained for loads of 1.0 g VS/L (VS, total volatile solids). The methane yield coefficient increased from 88 to 172 mLSTP/g VS (STP, 0 °C, 1 atm) after the pre-treatment, while biodegradability was found to be around 81% (in VS). Moreover, the allowed organic loading rate and methane production rate observed for the sewage sludge reached values of up to 4.1 kg VS/m(3)·d and 1270 LSTP/m(3)·d, respectively.

  7. Polychlorinated naphthalenes in sewage sludge from wastewater treatment plants in China.

    PubMed

    Zhang, Haiyan; Xiao, Ke; Liu, Jiyan; Wang, Thanh; Liu, Guorui; Wang, Yawei; Jiang, Guibin

    2014-08-15

    Polychlorinated naphthalenes (PCNs) were nominated as persistent organic pollutants candidate in the Stockholm Convention in 2011. In this study, the profiles, concentrations and spatial distributions of PCNs were analyzed in 30 sewage sludge samples from wastewater treatment plants (WWTPs) in China. Concentrations of Σ75PCNs in sludge samples were in the range of 1.05-10.9 ng/g dry weight (dw) with a mean value of 3.98 ng/g dw. The predominant homologues in the sludge were mono- to tetra-CNs, accounting for approximately 85% of total PCNs. The total toxic equivalent quantities (TEQs) of dioxin-like PCN congeners ranged from 0.04 to 2.28 pg/g dw with a mean value of 0.36 pg/g dw, which were lower than the maximum permissible TEQ concentrations in sludge for land application in China. Levels of PCNs and TEQs in sludge were relatively higher in samples from highly industrialized and developed cities in eastern China, implying a possible link between PCN contamination and the local economic development, but more studies are warranted to corroborate this. Industrial sources might be important contributors of PCNs to sewage sludge in China.

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

    PubMed

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

    2012-03-01

    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.

  9. SLUDGE TREATMENT PROJECT COST COMPARISON BETWEEN HYDRAULIC LOADING AND SMALL CANISTER LOADING CONCEPTS

    SciTech Connect

    GEUTHER J; CONRAD EA; RHOADARMER D

    2009-08-24

    The Sludge Treatment Project (STP) is considering two different concepts for the retrieval, loading, transport and interim storage of the K Basin sludge. The two design concepts under consideration are: (1) Hydraulic Loading Concept - In the hydraulic loading concept, the sludge is retrieved from the Engineered Containers directly into the Sludge Transport and Storage Container (STSC) while located in the STS cask in the modified KW Basin Annex. The sludge is loaded via a series of transfer, settle, decant, and filtration return steps until the STSC sludge transportation limits are met. The STSC is then transported to T Plant and placed in storage arrays in the T Plant canyon cells for interim storage. (2) Small Canister Concept - In the small canister concept, the sludge is transferred from the Engineered Containers (ECs) into a settling vessel. After settling and decanting, the sludge is loaded underwater into small canisters. The small canisters are then transferred to the existing Fuel Transport System (FTS) where they are loaded underwater into the FTS Shielded Transfer Cask (STC). The STC is raised from the basin and placed into the Cask Transfer Overpack (CTO), loaded onto the trailer in the KW Basin Annex for transport to T Plant. At T Plant, the CTO is removed from the transport trailer and placed on the canyon deck. The CTO and STC are opened and the small canisters are removed using the canyon crane and placed into an STSC. The STSC is closed, and placed in storage arrays in the T Plant canyon cells for interim storage. The purpose of the cost estimate is to provide a comparison of the two concepts described.

  10. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

    PubMed

    Huang, Hua-Jun; Yuan, Xing-Zhong

    2016-01-01

    Various hydrothermal treatment methods, including hydrothermal carbonization, liquefaction and sub/super-critical water gasification, have been applied to the disposal of sewage sludge for producing bio-materials or bio-fuels. It has become a research hotspot whether the heavy metals contained in sewage sludge can be well treated/stabilized after the hydrothermal treatments. This review firstly summarized the methods of assessing heavy metals' contamination level/risk and then discussed the migration and transformation behaviors of heavy metals from the following aspects: the effect of reaction temperature, the effect of additives (catalysts and other biomass), the effect of the type of solvent and the effect of reaction time. This review can provide an important reference for the further study of the migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

  11. Engineering evaluation of neutralization and precipitation processes applicable to sludge treatment project

    SciTech Connect

    Klem, M.J.

    1998-08-25

    Engineering evaluations have been performed to determine likely unit operations and methods required to support the removal, storage, treatment and disposal of solids/sludges present in the K Basins at the Hanford Site. This evaluation was initiated to select a neutralization process for dissolver product solution resulting from nitric acid treatment of about 50 m{sup 3} of Hanford Site K Basins sludge. Neutralization is required to meet Tank Waste Remediation Waste System acceptance criteria for storage of the waste in the double shell tanks after neutralization, the supernate and precipitate will be transferred to the high level waste storage tanks in 200E Area. Non transuranic (TRU) solids residue will be transferred to the Environmental Restoration Disposal Facility (ERDF). This report presents an overview of neutralization and precipitation methods previously used and tested. This report also recommends a neutralization process to be used as part of the K Basins Sludge Treatment Project and identifies additional operations requiring further evaluation.

  12. Feasibility of sulfide control in sewers by reuse of iron rich drinking water treatment sludge.

    PubMed

    Sun, Jing; Pikaar, Ilje; Sharma, Keshab Raj; Keller, Jürg; Yuan, Zhiguo

    2015-03-15

    Dosage of iron salt is the most commonly used method for sulfide control in sewer networks but incurs high chemical costs. In this study, we experimentally investigate the feasibility of using iron rich drinking water treatment sludge for sulfide control in sewers. A lab-scale rising main sewer biofilm reactor was used. The sulfide concentration in the effluent decreased from 15.5 to 19.8 mgS/L (without dosing) to below 0.7-2.3 mgS/L at a sludge dosing rate achieving an iron to total dissolved inorganic sulfur molar ratio (Fe:S) of 1:1, with further removal of sulfide possible by prolonging the reaction time. In fact, batch tests revealed an Fe consumption to sulfide removal ratio of 0.5 ± 0.02 (mole:mole), suggesting the possible occurrence of other reactions involving the removal of sulfide. Modelling revealed that the reaction between iron in sludge and sulfide has reaction orders of 0.65 ± 0.01 and 0.77 ± 0.02 with respect to the Fe and sulfide concentrations, respectively. The addition of sludge slightly increased the total chemical oxidation demand (tCOD) concentration (by approximately 12%) as expected, but decreased the soluble chemical oxidation demand (sCOD) concentration and methane formation by 7% and 20%, respectively. Some phosphate removal (13%) was also observed at the sludge dosing rate of 1:1 (Fe:S), which is beneficial to nutrient removal from the wastewater. Overall, this study suggests that dosing iron-rich drinking water sludge to sewers could be an effective strategy for sulfide removal in sewer systems, which would also reduce the sludge disposal costs for drinking water treatment works. However, its potential side-effects on sewer sedimentation and on the wastewater treatment plant effluent remain to be investigated.

  13. 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...

  14. 40 CFR 721.10636 - Slimes and sludges, automotive coating, wastewater treatment, solid waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., wastewater treatment, solid waste. 721.10636 Section 721.10636 Protection of Environment ENVIRONMENTAL..., wastewater treatment, solid waste. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as slimes and sludges, automotive coating, wastewater...

  15. 40 CFR 721.10636 - Slimes and sludges, automotive coating, wastewater treatment, solid waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., wastewater treatment, solid waste. 721.10636 Section 721.10636 Protection of Environment ENVIRONMENTAL..., wastewater treatment, solid waste. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as slimes and sludges, automotive coating, wastewater...

  16. Combined ultrasonication and thermal pre-treatment of sewage sludge for increasing methane production.

    PubMed

    Trzcinski, Antoine Prandota; Tian, Xinbo; Wang, Chong; Lin, Li Leonard; Ng, Wun Jern

    2015-01-01

    This article focuses on the combination of ultrasonic and thermal treatment of sewage sludge (SS). The combination involved ultrasonicating a fraction of the sludge and thermal treatment at various temperatures and this resulted in solubilization of proteins and carbohydrates, and so contributing to increased COD solubilization. During the treatment, SCOD, soluble proteins and carbohydrates increased from 760 mg L(-1) to 10,200 mg L(-1), 110 mg L(-1) to 2,900 mg L(-1) and 60 mg L(-1) to 630 mg L(-1), respectively. It was found ultrasonication of only a fraction of the sludge (>20%) followed by thermal treatment led to significant improvement compared to thermal and ULS treatments applied on their own. At 65°C, the kinetic of solubilization was improved and the hyper-thermophilic treatment time could be reduced to a few hours when ultrasonication was used first. A linear correlation (R(2) = 95%) was found between the SCOD obtained after ultrasonication pre-treatment and anaerobic biodegradability. The combined treatment resulted in 20% increase in biogas production during the anaerobic digestion of the pre-treated sludge.

  17. Fractions composition study of the pyrolysis oil obtained from sewage sludge treatment plant.

    PubMed

    Silva, R V S; Romeiro, G A; Veloso, M C C; Figueiredo, M K-K; Pinto, P A; Ferreira, A F; Gonçalves, M L A; Teixeira, A M; Damasceno, R N

    2012-01-01

    In this work the parameters of Low Temperature Conversion--LTC were applied in a centrifuged sludge from a sewage treatment plant located in Rio de Janeiro, Brazil. Before the conversion, the sludge was dried and analyzed by TGA to observe its behavior with increasing temperature. The chemical composition of the crude pyrolysis oil was analyzed by FTIR, 1H NMR and GC-MS. The results showed that the oil is a mixture of hydrocarbons, oxygenated and nitrogenated compounds. Using a catalytic treatment it was possible to fractionate the oil where the predominant constituents were hydrocarbons showing that the cracking was effective. An important result was the difference between the calorific value of dry sludge (10 MJ kg(-1)), the pyrolysis oil (36 MJ kg(-1)) and one of the fractions separated by catalytic cracking (40 MJ kg(-1)) when compared with commercial diesel (45 MJ kg(-1)).

  18. Enhancement of anaerobic digestion efficiency of wastewater sludge and olive waste: Synergistic effect of co-digestion and ultrasonic/microwave sludge pre-treatment.

    PubMed

    Alagöz, B Aylin; Yenigün, Orhan; Erdinçler, Ayşen

    2015-12-01

    This study investigates the effect of ultrasonic and microwave pre-treatment on biogas production from the anaerobic co-digestion of olive pomace and wastewater sludges. It was found that co-digestion of wastewater sludge with olive pomace yielded around 0.21 L CH4/g VS added, whereas the maximum methane yields from the mono-digestion of olive pomace and un-pretreated wastewater sludges were 0.18 and 0.16L CH4/g VS added. In the same way, compared to mono-digestion of these substrates, co-digestion increased methane production by 17-31%. The microwave and ultrasonic pre-treatments applied to sludge samples prior to co-digestion process led to further increase in the methane production by 52% and 24%, respectively, compared to co-digestion with un-pretreated wastewater sludge. The highest biogas and methane yields were obtained from the co-digestion of 30 min microwave pre-treated wastewater sludges and olive pomace to be 0.46 L/g VS added and 0.32 L CH4/g VS added, respectively.

  19. Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment.

    PubMed

    Remy, C; Lesjean, B; Waschnewski, J

    2013-01-01

    This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO(2), CH(4), N(2)O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (-162 MJ/PE(COD) * a) and carbon footprint (-11.6 kg CO(2)-eq/PE(COD) * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.

  20. Application of alkaline treatment for sludge decrement and humic acid recovery.

    PubMed

    Li, Huan; Jin, Yiying; Nie, Yongfeng

    2009-12-01

    A new method was introduced to reduce waste activated sludge and extract humic acid for liquid fertilizer. Sludge was disintegrated with NaOH (0.4 g/g dry solid, 8 h) and then centrifuged to obtain the supernatant. The residual sludge was then dewatered, while the supernatant was used to extract humic acid with an ultrafiltration membrane. The results showed that the alkaline treatment dissolved more than half of the sludge organic matter, which was composed of 24% humic acid by mass. After the supernatant was concentrated 20 times using a membrane with a molecular weight cutoff of 1000, the retentate contained 94.5% of the dissolved organics and could be used to produce humic acid fertilizer. Additionally, only 26% of the NaOH was consumed and the residual NaOH in the permeate flux could be reused. Due to the removal of water and organics, the dewatered sludge could be reduced by 60% when compared to samples that did not receive the alkaline treatment.

  1. Fate of cyanobacteria and their metabolites during water treatment sludge management processes.

    PubMed

    Ho, Lionel; Dreyfus, Jennifer; Boyer, Justine; Lowe, Todd; Bustamante, Heriberto; Duker, Phil; Meli, Tass; Newcombe, Gayle

    2012-05-01

    Cyanobacteria and their metabolites are an issue for water authorities; however, little is known as to the fate of coagulated cyanobacterial-laden sludge during waste management processes in water treatment plants (WTPs). This paper provides information on the cell integrity of Anabaena circinalis and Cylindrospermopsis raciborskii during: laboratory-scale coagulation/sedimentation processes; direct filtration and backwashing procedures; and cyanobacterial-laden sludge management practices. In addition, the metabolites produced by A. circinalis (geosmin and saxitoxins) and C. raciborskii (cylindrospermopsin) were investigated with respect to their release (and possible degradation) during each of the studied processes. Where sedimentation was used, coagulation effectively removed cyanobacteria (and intracellular metabolites) without any considerable exertion on coagulant demand. During direct filtration experiments, cyanobacteria released intracellular metabolites through a stagnation period, suggesting that more frequent backwashing of filters may be required to prevent floc build-up and metabolite release. Cyanobacteria appeared to be protected within the flocs, with minimal damage during backwashing of the filters. Within coagulant sludge, cyanobacteria released intracellular metabolites into the supernatant after 3d, even though cells remained viable up to 7d. This work has improved the understanding of cyanobacterial metabolite risks associated with management of backwash water and sludge and is likely to facilitate improvements at WTPs, including increased monitoring and the application of treatment strategies and operational practices, with respect to cyanobacterial-laden sludge and/or supernatant recycle management.

  2. Combined compost and vermicomposting process in the treatment and bioconversion of sludge.

    PubMed

    Alidadi, H; Parvaresh, A R; Shahmansouri, M R; Pourmoghadas, H; Najafpoor, A A

    2007-11-01

    Traditional thermophillic composting is commonly for treatment of sludge. A related technique as vermicomposting process, using earthworms to breakdown sludge, is also becoming popular. These two techniques have their inherent advantages and disadvantages. The combined approach suggested in this study to enhance the overall process and improve the products qualities. Two systems, vermicomposting and combined compost-vermicomposting processes, have been investigated in this study. The sludge used in this study was obtained from the drying beds of South Isfahan wastewater treatment plant. The sludge mixed with sawdust to provide C/N ratio of 25/1. Eisenia fetida was the species of earthworms used in the vermicomposting processes. The results obtained indicate reduction in the amount of volatile solids, total carbon and C/N ratio with the vermicompost age, which indicates the reduction in the biodegradable organic content and mineralization of sludge. Also increase in phosphorus concentration by the end process because of mineralization of organic matter. The results indicate that, a system that combines the two mentioned processes not only shortens stabilization time, but also improves the products quality. Combining the two systems resulted in a product that was more stable and homogenous; the product could meet the pathogen reduction requirements.

  3. 40 CFR 35.2101 - Advanced treatment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Advanced treatment. 35.2101 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2101 Advanced treatment. Projects proposing advanced treatment shall be awarded grant assistance only after the project has...

  4. Use of lysis and recycle to control excess sludge production in activated sludge treatment: bench scale study and effect of chlorinated organic compounds.

    PubMed

    Nolasco, M A; Campos, A L O; Springer, A M; Pires, E C

    2002-01-01

    The most widely used treatment system in the pulp and paper industry--the activated sludge--produces high quantities of sludge which need proper disposal. In this paper a modified activated sludge process is presented. A synthetic wastewater, prepared to simulate the effluent of bleached and unbleached pulp and paper plant wastewater, was submitted to treatment in a bench scale aerobic reactor. The excess sludge was lysed in a mechanical mill--Kaddy mill--and totally recycled to the aeration tank. In the first phase the synthetic wastewater, without the chlorinated compounds, was fed to the reactor. In the second phase increasing dosages of the chlorinated compounds were used. Total recycle of excess sludge after disintegration did not produce adverse effects. During the first phase average COD removal efficiency was 65% for the control unit, which operated in a conventional way, and 63% for the treatment unit, which operated with total recycle. During the second phase the COD removal efficiency increased to 77% in the control unit and 75% in the treatment unit. Chlorinated organics removal was 85% in the treatment unit and 86% for the control unit. These differences are not significant.

  5. Sono-thermal pre-treatment of waste activated sludge before anaerobic digestion.

    PubMed

    Şahinkaya, Serkan; Sevimli, Mehmet Faik

    2013-01-01

    Sonication and thermalization can be applied successfully to disrupt the complex waste activated sludge (WAS) floc structure and to release extra and intra cellular polymeric substances into soluble phase along with solubilization of particulate organic matters, before sludge digestion. In this study, sonication has been combined with thermalization to improve its disintegration efficiency. It was aimed that rise in temperature occurring during the sonication of sludge was used to be as an advantage for the following thermalization in the combined pre-treatment. Thus, the effects of sonication, thermalization and sono-thermalization on physical and chemical properties of sludge were investigated separately under different pre-treatment conditions. The disintegration efficiencies of these methods were in the following descending order: sono-thermalization > sonication > thermalization. The optimum operating conditions for sono-thermalization were determined as the combination of 1-min sonication at 1.0 W/mL and thermalization at 80 °C for 1h. The influences of sludge pre-treatment on biodegradability of WAS were experienced with biochemical methane potential assay in batch anaerobic reactors. Relative to the control reactor, total methane production in the sono-thermalized reactor increased by 13.6% and it was more than the sum of relative increases achieved in the sonicated and thermalized reactors. Besides, the volatile solids and total chemical oxygen demand reductions in the sono-thermalized reactor were enhanced as well. However, it was determined that sludge pre-treatment techniques applied in this study was not feasible due to their high energy requirements.

  6. Speciation Dynamics of Phosphorus during (Hydro)Thermal Treatments of Sewage Sludge.

    PubMed

    Huang, Rixiang; Tang, Yuanzhi

    2015-12-15

    (Hydro)thermal treatments of sewage sludge from wastewater treatment process can significantly reduce waste volume and transform sludge into valuable products such as pyrochar and hydrochar. Given the global concern with phosphorus (P) resource depletion, P recycling/reclamation from or direct soil application of the derived chars can be potential P recycling practices. In order to evaluate P recyclability as well as the selection and optimization of treatment techniques, it is critical to understand the effects of different treatment techniques and conditions on P speciation and distribution. In the present study, we systematically characterized P speciation in chars derived from thermal (i.e., pyrolysis) and hydrothermal treatments of municipal sewage sludge using complementary chemical extraction and nuclear magnetic resonance (NMR) spectroscopy methods. P species in the raw activated sludge was dominated by orthophosphate and long-chain polyphosphates, whereas increased amounts of pyrophosphate and short-chain polyphosphates formed after pyrolysis at 250-600 °C. In contrast, hydrothermal treatments resulted in the production of only inorganic orthophosphate in the hydrochar. In addition to the change of molecular speciation, thermal treatments also altered the physical state and extractability of different P species in the pyrochars from pyrolysis, with both total P and polyphosphate being less extractable with increasing pyrolysis temperature. Results from this study suggest that P speciation and availability in sludge-derived chars are tunable by varying treatment techniques and conditions, and provide fundamental knowledge basis for the design and selection of waste management strategies for better nutrient (re)cycling and reclamation.

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

    PubMed

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

    2013-02-15

    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 μg/kg, dry weight (dw)], followed by macrolides (85.1 μg/kg, dw), and sulfonamides (22.7 μg/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.

  8. Treating Sludges

    ERIC Educational Resources Information Center

    Josephson, Julian

    1978-01-01

    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)

  9. Mercury-contaminated sludge treatment by dredging in Minamata Bay

    SciTech Connect

    Yoshinaga, Kiyoto

    1995-12-31

    To eradicate Minamata Disease, caused by the discharge of sewage containing methyl mercury and its accumulation in fish and shellfish through the food cycle, a large-scale sediment disposal project was conducted with special care taken to prevent new pollution resulting from the project itself. The basic approach to sediment disposal was to construct a highly watertight revetment to reclaim the inner area of the bay and then confine sediment dredged from the remaining contaminated area in the reclamation area through surface treatment. Before sediment disposal, boundary nets were installed to enclose the work area to prevent the mixing of contaminated and noncontaminated fish. Dredging work was successfully carried out by using four cutterless suction dredgers, newly developed in advance for minimizing resuspension of sediments. Dredged material was discharged into the reclamation area, filled up to sea level, and covered with a sandproof membrane, lightweight volcanic ash earth, and mountain soil.

  10. Audits for advanced treatment dosimetry

    NASA Astrophysics Data System (ADS)

    Ibbott, G. S.; Thwaites, D. I.

    2015-01-01

    Radiation therapy has advanced rapidly over the last few decades, progressing from 3D conformal treatment to image-guided intensity modulated therapy of several different flavors, both 3D and 4D and to adaptive radiotherapy. The use of intensity modulation has increased the complexity of quality assurance and essentially eliminated the physicist's ability to judge the validity of a treatment plan, even approximately, on the basis of appearance and experience. Instead, complex QA devices and procedures are required at the institutional level. Similarly, the assessment of treatment quality through remote and on-site audits also requires greater sophistication. The introduction of 3D and 4D dosimetry into external audit systems must follow, to enable quality assurance systems to perform meaningful and thorough audits.

  11. Energy potential and alternative usages of biogas and sludge from UASB reactors: case study of the Laboreaux wastewater treatment plant.

    PubMed

    Rosa, A P; Conesa, J A; Fullana, A; Melo, G C B; Borges, J M; Chernicharo, C A L

    2016-01-01

    This work assessed the energy potential and alternative usages of biogas and sludge generated in upflow anaerobic sludge blanket reactors at the Laboreaux sewage treatment plant (STP), Brazil. Two scenarios were considered: (i) priority use of biogas for the thermal drying of dehydrated sludge and the use of the excess biogas for electricity generation in an ICE (internal combustion engine); and (ii) priority use of biogas for electricity generation and the use of the heat of the engine exhaust gases for the thermal drying of the sludge. Scenario 1 showed that the electricity generated is able to supply 22.2% of the STP power demand, but the thermal drying process enables a greater reduction or even elimination of the final volume of sludge to be disposed. In Scenario 2, the electricity generated is able to supply 57.6% of the STP power demand; however, the heat in the exhaust gases is not enough to dry the total amount of dehydrated sludge.

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

    PubMed

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

    2015-01-01

    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 μg/l as far as for the native activated sludge it came only to 100-110 μg/l.

  13. Continuous sulfidogenic wastewater treatment with iron sulfide sludge oxidation and recycle.

    PubMed

    Deng, Dongyang; Lin, Lian-Shin

    2017-05-01

    This study evaluated the technical feasibility of packed-bed sulfidogenic bioreactors dosed with ferrous chloride for continuous wastewater treatment over a 450-day period. In phase I, the bioreactors were operated under different combinations of carbon, iron, and sulfate mass loads without sludge recycling to identify optimal treatment conditions. A COD/sulfate mass ratio of 2 and a Fe/S molar ratio of 1 yielded the best treatment performance with COD oxidation rate of 786 ± 82 mg/(L⋅d), which resulted in 84 ± 9% COD removal, 94 ± 6% sulfate reduction, and good iron retention (99 ± 1%) under favorable pH conditions (6.2-7.0). In phase II, the bioreactors were operated under this chemical load combination over a 62-day period, during which 7 events of sludge collection, oxidation, and recycling were performed. The collected sludge materials contained both inorganic and organic matter with FeS and FeS2 as the main inorganic constituents. In each event, the sludge materials were oxidized in an oxidizing basin before recycling to mix with the wastewater influent. Sludge recycling yielded enhanced COD removal (90 ± 6% vs. 75 ± 7%), and better effluent quality in terms of pH (6.8 ± 0.1 vs. 6.5 ± 0.2), iron (0.7 ± 0.5 vs. 1.9 ± 1.7 mg/L), and sulfide-S (0.3 ± 0.1 vs. 0.4 ± 0.1 mg/L) removal compared to the baseline operation without sludge recycling during phase II. This process exhibited treatment stability with reasonable variations, and fairly consistent sludge content over long periods of operation under a range of COD/sulfate and Fe/S ratios without sludge recycling. The bioreactors were found to absorb recycling-induced changes efficiently without causing elevated suspended solids in the effluents.

  14. Adsorption of methylene blue using modified adsorbents from drinking water treatment sludge.

    PubMed

    Nageeb Rashed, M; El-Daim El Taher, M A; Fadlalla, Somaya M M

    2016-10-01

    This study aims to explore the preparation and application of alum sludge (AS) and mud sludge (MS) from a drinking water treatment plant to remove methylene blue (MB) dye from aqueous solution. The sludge (MS and AS) was treated by chemical and physical activation to obtain new adsorbents. The adsorption experiments were carried out under different conditions of initial dye concentration (50-100 mg/L) adsorbent dosage (0.05-0.25 g), solution pH (3-9), temperature (20-60 °C) and contact time (20-90 min). Scanning electron microscopy (SEM) and X-ray diffraction instruments were used for characterization of the developed adsorbents. The results show that sludge activated by nitric acid (0.25 M HNO3) and pyrolysis at 700 °C were the best chemically and physically activated adsorbents. The optimum adsorption conditions for the adsorption of MB are 100 ppm initial dye concentration, 1 hour contact time, 250 °C solution temperature, pH 7 and 0.25 g adsorbent dosage. Application of the Langmuir and Freundlich Isotherm models showed that adsorbents fitted the Langmuir model well. SEM studies indicated the porous structural aspects of sludge suitable for removing MB dye.

  15. Composting. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Arasmith, E. E.

    Composting is a lesson developed for a sludge treatment and disposal course. The lesson discusses the basic theory of composting and the basic operation, in a step-by-step sequence, of the two typical composting procedures: windrow and forced air static pile. The lesson then covers basic monitoring and operational procedures. The instructor's…

  16. RECYCLING OF WATER TREATMENT PLANT SLUDGE VIA LAND APPLICATION: ASSESSMENT OF RISK

    EPA Science Inventory

    Water treatment sludges (WTS) offer potential benefits when applied to soil and recycling of the waste stream via land application has been proposed as a management option. Recycling of WTS to the land helps conserve landfill disposal capacity and natural resources, but potential...

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

    PubMed

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

    2012-01-01

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

  18. Fate of emerging and priority micropollutants during the sewage sludge treatment: Case study of Paris conurbation. Part 1: Contamination of the different types of sewage sludge.

    PubMed

    Mailler, R; Gasperi, J; Patureau, D; Vulliet, E; Delgenes, N; Danel, A; Deshayes, S; Eudes, V; Guerin, S; Moilleron, R; Chebbo, G; Rocher, V

    2017-01-01

    This article provides data on the contamination of different kinds of sludge (raw, centrifuged, digested, thermally dried sludge and sludge cake) from Paris conurbation by 71 various pollutants including pharmaceutical products (PHPs), hormones, perfluorinated acids (PFAs), linear alkylbenzene sulfonate (LAS), alkylphenols (APs), phthalates (PAEs), polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs). Very high contents of LAS (0.1-10g/kg dry matter - DM) compared to other compounds were found in all types of sludge followed by DEHP (10-100mg/kg DM) and fluoroquinolones (1-100mg/kg DM). APs were measured at intermediary contents in Parisian sludge, lying in the 2-20mg/kg DM range. Finally, hormones, PAHs, PCBs, PAEs, PFAs and the remaining PHPs were all found at contents lower than 1mg/kg DM. For most compounds (PHPs, PFOS, DEHP, PAHs), no significant differences in the micropollutant contents were found for similar types of sludge from different WWTP in Paris, highlighting the homogeneity of sludge contamination in downstream Paris catchment. The variability of concentration is rather high (coefficient of variation >100%) for several PHPs, PFAs or PCBs while it is moderate (<100%) or low (<50%) for fluoroquinolones, hormones, PAHs, APs or LAS. In addition, digestion seems to have a buffer effect as variabilities are lower in digested sludge for PHPs, PFAs, APs and PCBs. During sludge treatment (centrifugation, digestion, thermal drying, sludge conditioning+press filtration), the hormones, LAS, APs, PAHs, DEHP and PCBs concentrations increased, while those of PHPs and PFAs decreased. In the case of digestion, the increase of content can be explained by no pollutant removal or a lower removal than DM removal (concentration phenomenon) whereas the decrease underlines that the compound is more removed than the DM. In any case, these concentration variations presuppose the mechanisms of dissipation that could be attributed to volatilization, biotic or

  19. IASON - Intelligent Activated Sludge Operated by Nanotechnology - Hydrogel Microcarriers in Wastewater Treatment

    NASA Astrophysics Data System (ADS)

    Fleit, E.; Melicz, Z.; Sándor, D.; Zrínyi, M.; Filipcsei, G.; László, K.; Dékány, I.; Király, Z.

    Performance of biological wastewater treatment depends to a large extent on mechanical strength, size distribution, permeability and other textural properties of the activated sludge flocs. A novel approach was developed in applying synthetic polymer materials to organize floc architecture instead of spontaneously formed activated sludge floc. Developed microcarrier polymer materials were used in our experiments to mitigate technological goals. Preliminary results suggest that the PVA-PAA (polyvinyl alcohol-polyacrylic acid copolymer) is a feasible choice for skeleton material replacing "traditional" activated sludge floc. Use of PVA-PAA hydrogel material as microreactors and methods for biofilm formation of wastewater bacteria on the carrier material are described. Laboratory scale experimental results with microscopic size bioreactors and their potential application for simultaneous nitrification and denitrification are presented.

  20. Multimedia sampling for dioxin at a strip mine reclaimed with sludge from bleached kraft wastewater treatment

    SciTech Connect

    Krouskop, D.J.; Ayers, K.C. ); Proctor, J.L. )

    1991-04-01

    This paper reports that mead conducted a two-year dioxin testing program on strip-mined land being reclaimed with sludge from the wastewater treatment plant of its bleached kraft mill. Many different samples were analyzed for both 2,3,7,8-TCDD (or dioxin) and 2,3,7,8-TCDF (or furan). The study included biodiversity studies to determine the total environmental impact. The results indicate that the sludge is an excellent reclamation material that improves the biodiversity at the site. The tracer dioxin in the sludge does not exhibit any significant migration or bioavailability when used for reclaiming strip mines. These findings differ from assumptions sometimes used in assessing the environmental risks of dioxin.

  1. Treatment of advanced esophageal cancer

    SciTech Connect

    Kelsen, D.

    1982-12-01

    When radiation therapy is used for palliation of obstruction in patients with advanced esophageal carcinoma, an improvement in dysphagia can be expected in approximately 50% of patients. Major objective responses have rarely been quantitied but, in one study, were seen in 33% patients. Recurrence of dysphagia is usually seen within 2-6 months of treatment. Radiation toxicities and complications, even when used with palliative intent, can be substantial and include esophagitis, tracheoesophageal or esophageal-aortic fistula, mediastinitis, hemorrhage, pneumonitis, and myelosuppression. (JMT)

  2. Phosphorus removal by acid mine drainage sludge from secondary effluents of municipal wastewater treatment plants.

    PubMed

    Wei, Xinchao; Viadero, Roger C; Bhojappa, Shilpa

    2008-07-01

    Acid mine drainage (AMD) sludge, a waste product from coal mine water treatment, was used in this study as an adsorbent to develop a cost-effective treatment approach to phosphorus removal from municipal secondary effluents. Batch tests were carried out to study the effects of pH, temperature, concentration, and contact time for phosphorus removal from wastewater. Batch tests were followed by continuous flow tests using a continuous stirred tank reactor (CSTR). Adsorption of orthophosphate onto AMD sludge particles followed the Freundlich isotherm model with an adsorption capacity ranging from 9.89 to 31.97 mg/g when the final effluent concentration increased from 0.21 to 13.61 mg P/L. P adsorption was found to be a rather rapid process and neutral or acidic pH enhanced phosphorus removal. Based on a thermodynamic assessment, P adsorption by AMD sludge was found to be endothermic; consequently, an increase in temperature could also favor phosphorus adsorption. Results from batch tests showed that leaching of metals common to AMD sludges was not likely to be a major issue of concern over the typical pH range (6-8) of secondary wastewater effluents. CSTR tests with three types of water (synthetic wastewater, river water, and municipal secondary effluent) illustrated that P adsorption by AMD sludge was relatively independent of the presence of other ionic species. In treating municipal secondary effluent, a phosphorus removal efficiency in excess of 98% was obtained. Results of this study indicated that it was very promising to utilize AMD sludge for phosphorus removal from secondary effluents and may be relevant to future efforts focused on the control of eutrophication in surface waters.

  3. Treatment of sewage sludge in a continuous-flow radiofrequency-oxidation system.

    PubMed

    Lo, Kwang V; Srinivasan, Asha; Liao, Ping H

    2017-04-01

    This study explored the applicability of a pilot-scale continuous-flow radiofrequency (RF) heating system to treat sewage sludge by the RF-oxidation process (RF/H2O2). Depending on temperature and hydrogen peroxide dosage, high amounts of soluble chemical oxygen demand and volatile fatty acid were produced, and phosphates, nitrogen, and metals were solubilized. A high temperature and/or a higher H2O2 dosage implemented in this system yielded high solubilization of organic matters. Orthophosphate increased with an increase in treatment temperature up to 60°C, its concentration decreased as temperature further increased. There was little effect on orthophosphate release by varying H2O2 dosage. The efficiency of the RF/H2O2 process was comparable to the microwave (MW) enhanced advanced oxidation process (MW/H2O2-AOP), in terms of solids disintegration and nutrient release; however, the solubilization rate was lower for RF/H2O2 process. The overall energy consumed by the RF/H2O2 process was higher than the MW/H2O2-AOP.

  4. MWIP: Surrogate formulations for thermal treatment of low-level mixed waste. Part 4, Wastewater treatment sludges

    SciTech Connect

    Bostick, W.D.; Hoffmann, D.P.; Stevenson, R.J.; Richmond, A.A.; Bickford, D.F.

    1994-01-01

    The category of sludges, filter cakes, and other waste processing residuals represent the largest volume of low-level mixed (hazardous and radioactive) wastes within the US Department of Energy (DOE) complex. Treatment of these wastes to minimize the mobility of contaminants, and to eliminate the presence of free water, is required under the Federal Facility Compliance Act agreements between DOE and the Environmental Protection Agency. In the text, we summarize the currently available data for several of the high priority mixed-waste sludge inventories within DOE. Los Alamos National Laboratory TA-50 Sludge and Rocky Flats Plant By-Pass Sludge are transuranic (TRU)-contaminated sludges that were isolated with the use of silica-based filter aids. The Oak Ridge Y-12 Plant West End Treatment Facility Sludge is predominantly calcium carbonate and biomass. The Oak Ridge K-25 Site Pond Waste is a large-volume waste stream, containing clay, silt, and other debris in addition to precipitated metal hydroxides. We formulate ``simulants`` for the waste streams described above, using cerium oxide as a surrogate for the uranium or plutonium present in the authentic material. Use of nonradiological surrogates greatly simplifies material handling requirements for initial treatability studies. The use of synthetic mixtures for initial treatability testing will facilitate compositional variation for use in conjunction with statistical design experiments; this approach may help to identify any ``operating window`` limitations. The initial treatability testing demonstrations utilizing these ``simulants`` will be based upon vitrification, although the materials are also amenable to testing grout-based and other stabilization procedures. After the feasibility of treatment and the initial evaluation of treatment performance has been demonstrated, performance must be verified using authentic samples of the candidate waste stream.

  5. Methane and nitrous oxide emissions following anaerobic digestion of sludge in Japanese sewage treatment facilities.

    PubMed

    Oshita, Kazuyuki; Okumura, Takuya; Takaoka, Masaki; Fujimori, Takashi; Appels, Lise; Dewil, Raf

    2014-11-01

    Methane (CH4) and nitrous oxide (N2O) are potent greenhouse gases with global warming potentials (expressed in terms of CO2-equivalents) of 28 and 265, respectively. When emitted to the atmosphere, they significantly contribute to climate change. It was previously suggested that in wastewater treatment facilities that apply anaerobic sludge digestion, CH4 continues to be emitted from digested sludge after leaving the anaerobic digester. This paper studies the CH4 and N2O emissions from anaerobically digested sludge in the subsequent sludge treatment steps. Two full-scale treatment plants were monitored over a 1-year period. Average emissions of CH4 and N2O were 509±72 mg/m(3)-influent (wastewater) and 7.1±2.6 mg/m(3)-influent, respectively. These values accounted for 22.4±3.8% of the indirect reduction in CO2-emissions when electricity was generated using biogas. They are considered to be significant.

  6. Presence of radionuclides in sludge from conventional drinking water treatment plants. A review.

    PubMed

    Fonollosa, E; Nieto, A; Peñalver, A; Aguilar, C; Borrull, F

    2015-03-01

    The analysis of sludge samples generated during water treatment processes show that different radioisotopes of uranium, thorium and radium, among others can accumulate in that kind of samples, even the good removal rates obtained in the aqueous phase (by comparison of influent and effluent water concentrations). Inconsequence, drinking water treatment plants are included in the group of Naturally Occurring Radioactive Material (NORM) industries. The accumulation of radionuclides can be a serious problem especially when this sludge is going to be reused, so more exhaustive information is required to prevent the possible radiological impact of these samples in the environment and also on the people. The main aim of this review is to outline the current situation regarding the different studies reported in the literature up to date focused on the analysis of the radiological content of these sludge samples from drinking water treatment plants. In this sense, special attention is given to the recent approaches for their determination. Another important aim is to discuss about the final disposal of these samples and in this regard, sludge reuse (including for example direct agricultural application or also as building materials) are together with landfilling the main reported strategies.

  7. Application of acidic thermal treatment for one- and two-stage anaerobic digestion of sewage sludge.

    PubMed

    Takashima, M; Tanaka, Y

    2010-01-01

    The effectiveness of acidic thermal treatment (ATT) was examined in a 106-day continuous experiment, when applied to one- or two-stage anaerobic digestion of sewage sludge (4.3% TS). The ATT was performed at 170 °C and pH 5 for 1 hour (sulfuric acid for lowering pH). The one-stage process was mesophilic at 20 days hydraulic retention time (HRT), and incorporated the ATT as pre-treatment. The two-stage process consisted of a thermophilic digester at 5 days HRT and a mesophilic digester at 15 days HRT, and incorporated the ATT as interstage-treatment. On average, VSS reduction was 48.7% for the one-stage control, 65.8% for the one-stage ATT, 52.7% for the two-stage control and 67.6% for the two-stage ATT. Therefore, VSS reduction was increased by 15-17%, when the ATT was combined in both one- and two-stage processes. In addition, the dewaterability of digested sludge was remarkably improved, and phosphate release was enhanced. On the other hand, total methane production did not differ significantly, and color generation was noted in the digested sludge solutions with the ATT. In conclusion, the anaerobic digestion with ATT can be an attractive alternative for sludge reduction, handling, and phosphorus recovery.

  8. Treatment of low strength domestic wastewater by using upflow anaerobic sludge blanket process

    SciTech Connect

    Tang, N.H.; Torres, C.L.; Speece, R.E.

    1996-11-01

    The tropical environment of Puerto Rico offers great potential for using anaerobic treatment in place of conventional, aerobic activated sludge processes in the treatment of its warm, dilute municipal wastewaters. It will minimize the troublesome problem of land disposal of municipal sludges, achieve secondary effluent standards and not be an energy intensive form of treatment. When the infrastructure of sewage treatment needs to be improved, anaerobic sewage treatment may serve as one of the better alternatives. Anaerobic sewage treatment is a totally enclosed process. It has very little environmental impact on the surrounding areas of the treatment site. However, sometimes its effluent may cause serious odor problems. There are many small communities in Puerto Rico where the anaerobic process can be an ideal form of treatment for their sewage. This study is focused on using the upflow anaerobic sludge blanket (UASB) process for treating raw domestic sewage. The objectives of this study were to evaluate the performance and stability of the UASB process for treating raw sewage and to ascertain the effect on efficiency of hydraulic detention time of the UASB reactor. A further key objective was to evaluate the impact on process performance of a packed bed solids removals device following the UASB reactor.

  9. Pulp mill effluents: Activated sludge treatment process. (Latest citations from the Paper and Board, Printing, and Packaging Industries Research Associations database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning plant histories, laboratory analyses, field applications, performance evaluations, and cost factors of pulping mill activated sludge treatment facilities. Monitoring techniques of the activated sludge effluent treatment process, and operating problems and solutions are discussed. Computerized simulation of activated sludge plants is included. (Contains a minimum of 75 citations and includes a subject term index and title list.)

  10. Multistage treatment wetland for treatment of reject waters from digested sludge dewatering.

    PubMed

    Gajewska, M; Obarska-Pempkowiak, H

    2013-01-01

    The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75-80%, biochemical oxygen demand (BOD) 82.2-95.5% and total nitrogen 78.7-93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal.

  11. Model development with defined biological mechanisms for xenobiotic treatment activated sludge at steady state.

    PubMed

    Chong, Nyuk-Min

    2015-06-01

    Activated sludge treatment of a xenobiotic organic compound, much different from treatment of biogenic organics, must be modeled with interactions involving a two-part biomass of degrader and nondegrader, which selectively or competitively grow on a two-part substrate of input xenobiotic and its biogenic metabolites. A xenobiotic treatment model was developed which incorporates kinetics of the growth of degrader and nondegrader, the line dividing metabolites into xenobiotic and biogenic, yields of degrader and nondegrader from utilization of their parts of substrates, and kinetics of degrader reversion to nondegrader due to instability of the degradative element degraders carry. Experimental activated sludge operated for treatment of a xenobiotic generated data for calibration of the model. With the input of influent xenobiotic concentration, mean cell and hydraulic residence times, and calibrated parameters, the model readily outputs concentrations of degrader, nondegrader, and effluent biogenic residue that closely match the results obtained from experiments.

  12. Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants.

    PubMed

    Martí, N; Barat, R; Seco, A; Pastor, L; Bouzas, A

    2017-03-15

    Interest in phosphorus (P) recovery and reuse has increased in recent years as supplies of P are declining. After use, most of the P remains in wastewater, making Wastewater Treatment Plants (WWTPs) a vital part of P recycling. In this work, a new sludge management operation was studied by modeling in order to recover P in the form of struvite and minimize operating problems due to uncontrolled P precipitation in WWTPs. During the study, intensive analytical campaigns were carried out on the water and sludge lines. The results identified the anaerobic digester as a "hot spot" of uncontrolled P precipitation (9.5 gP/kg sludge) and highlighted possible operating problems due to the accumulation of precipitates. A new sludge line management strategy was simulated therefore using DESASS(©) software, consisting of the elutriation of the mixed sludge in the mixing chamber, to reduce uncontrolled P precipitation and to obtain a P-rich stream (primary thickener supernatant) to be used in a crystallization process. The key operating parameters were found to be: the elutriation flow from the mixing chamber to the primary thickener, the digestion flow and the sludge blanket height of the primary thickener, with optimized values between 70 and 80 m(3)/d, 90-100 m(3)/d and 1.4-1.5 m, respectively. Under these operating conditions, the preliminary results showed that P concentration in the primary thickener overflow significantly increased (from 38 to 100 mg PO4-P/L), which shows that this stream is suitable for use in a subsequent crystallization reactor to recover P in the form of struvite.

  13. Effects of black liquor shocks on activated sludge treatment of bleached kraft pulp mill wastewater.

    PubMed

    Morales, Gabriela; Pesante, Silvana; Vidal, Gladys

    2015-01-01

    Kraft pulp mills use activated sludge systems to remove organic matter from effluents. Process streams may appear as toxic spills in treatment plant effluents, such as black liquor, which is toxic to microorganisms of the activated sludge. The present study evaluates the effects of black liquor shocks in activated sludge systems. Four black liquor shocks from 883 to 3,225 mg chemical oxygen demand-COD L(-1) were applied during 24 hours in a continuously operating lab-scale activated sludge system. Removal efficiencies of COD, color and specific compounds were determined. Moreover, specific oxygen uptake rate (SOUR), sludge volumetric index (SVI) and indicator microorganisms were evaluated. Results show that the addition of black liquor caused an increase in COD removal (76-67%) immediately post shock; followed two days later by a decrease (-19-50%). On the other hand, SOUR ranged between 0.152 and 0.336 mgO2 g(-1) volatile suspended solids-VSS• min(-1) during shocks, but the initial value was reestablished at hour 24. When the COD concentration of the shock was higher than 1,014 mg/L, the abundance of stalked ciliates and rotifers dropped. Finally, no changes in SVI were observed, with values remaining in the range 65.8-40.2 mL g(-1) total suspended solids-TSS during the entire operating process. Based on the results, the principal conclusion is that the activated sludge system with the biomass adapted to the kraft pulp effluent could resist a black liquor shock with 3,225 mgCOD L(-1) of concentration during 24 h, under this study's conditions.

  14. Microcosm assays and Taguchi experimental design for treatment of oil sludge containing high concentration of hydrocarbons.

    PubMed

    Castorena-Cortés, G; Roldán-Carrillo, T; Zapata-Peñasco, I; Reyes-Avila, J; Quej-Aké, L; Marín-Cruz, J; Olguín-Lora, P

    2009-12-01

    Microcosm assays and Taguchi experimental design was used to assess the biodegradation of an oil sludge produced by a gas processing unit. The study showed that the biodegradation of the sludge sample is feasible despite the high level of pollutants and complexity involved in the sludge. The physicochemical and microbiological characterization of the sludge revealed a high concentration of hydrocarbons (334,766+/-7001 mg kg(-1) dry matter, d.m.) containing a variety of compounds between 6 and 73 carbon atoms in their structure, whereas the concentration of Fe was 60,000 mg kg(-1) d.m. and 26,800 mg kg(-1) d.m. of sulfide. A Taguchi L(9) experimental design comprising 4 variables and 3 levels moisture, nitrogen source, surfactant concentration and oxidant agent was performed, proving that moisture and nitrogen source are the major variables that affect CO(2) production and total petroleum hydrocarbons (TPH) degradation. The best experimental treatment yielded a TPH removal of 56,092 mg kg(-1) d.m. The treatment was carried out under the following conditions: 70% moisture, no oxidant agent, 0.5% of surfactant and NH(4)Cl as nitrogen source.

  15. Treatment of swine wastewater using chemically modified zeolite and bioflocculant from activated sludge.

    PubMed

    Guo, Junyuan; Yang, Chunping; Zeng, Guangming

    2013-09-01

    Sterilization, alkaline-thermal and acid-thermal treatments were applied to activated sludge and the pre-treated sludge was used as raw material for Rhodococcus R3 to produce polymeric substances. After 60 h of fermentation, bioflocculant of 2.7 and 4.2 g L(-1) were produced in sterilized and alkaline-thermal treated sludge as compared to that of 0.9 g L(-1) in acid-thermal treated sludge. Response surface methodology (RSM) was employed to optimize the treatment process of swine wastewater using the composite of bioflocculant and zeolite modified by calcining with MgO. The optimal flocculating conditions were bioflocculant of 24 mg L(-1), modified zeolite of 12 g L(-1), CaCl2 of 16 mg L(-1), pH of 8.3 and contact time of 55 min, and the corresponding removal rates of COD, ammonium and turbidity were 87.9%, 86.9%, and 94.8%. The use of the composite by RSM provides a feasible way to improve the pollutant removal efficiencies and recycle high-level of ammonium from wastewater.

  16. Removal of aluminum from drinking water treatment sludge using vacuum electrokinetic technology.

    PubMed

    Xu, Hang; Ding, Mingmei; Shen, Kunlun; Cui, Jianfeng; Chen, Wei

    2017-04-01

    A vacuum electrokinetic apparatus was operated at a municipal water supply plant in Wuxi, China to study the removal of aluminum from the plant's drinking water treatment sludge, high in trivalent aluminum content. The effect of several experimental variables (initial pH, potential gradient, and zone in the sludge tank) and the trivalent aluminum removal mechanism were analyzed. The speciation of trivalent aluminum mainly depends on the initial pH of drinking water treatment sludge, and more fractions of trivalent aluminum were migrated at pH 4 than at higher or lower pH. The application of high voltage can enhance the removal efficiency of aluminum. A three-dimensional electric field analysis explained the difference in the removal efficiency at different zones in the sludge tank. In view of energy consumption, when the initial pH was 4 and a potential gradient of 2 V cm(-1) was applied, achieving a final aluminum concentration of 30 g kg(-1) after 120 h. The specific energy consumption was 11.7 kWh kg(-1) of Al removed.

  17. Mass and energy balances of sludge processing in reference and upgraded wastewater treatment plants.

    PubMed

    Mininni, G; Laera, G; Bertanza, G; Canato, M; Sbrilli, A

    2015-05-01

    This paper describes the preliminary assessment of a platform of innovative upgrading solutions aimed at improving sludge management and resource recovery in wastewater treatment plants. The effectiveness of the upgrading solutions and the impacts of their integration in model reference plants have been evaluated by means of mass and energy balances on the whole treatment plant. Attention has been also paid to the fate of nitrogen and phosphorus in sludge processing and to their recycle back to the water line. Most of the upgrading options resulted in reduced production of dewatered sludge, which decreased from 45 to 56 g SS/(PE × day) in reference plants to 14-49 g SS/(PE × day) in the upgraded ones, with reduction up to 79% when wet oxidation was applied to the whole sludge production. The innovative upgrades generally entail an increased demand of electric energy from the grid, but energy recovery from biogas allowed to minimize the net energy consumption below 10 kWh/(PE × year) in the two most efficient solutions. In all other cases the net energy consumption was in the range of -11% and +28% of the reference scenarios.

  18. Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan.

    PubMed

    Hong, Jinglan; Hong, Jingmin; Otaki, Masahiro; Jolliet, Olivier

    2009-02-01

    Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.

  19. Sewage sludge treatment in a thermophilic membrane reactor (TMR): factors affecting foam formation.

    PubMed

    Collivignarelli, Maria Cristina; Castagnola, Federico; Sordi, Marco; Bertanza, Giorgio

    2016-11-04

    Foam formation in the excess sludge treatment facilities of biological wastewater treatment plants (WWTPs) may represent a critical issue as it could lead to several operative problems and reduce the overall plant performance. This trouble also affects a novel technology recently proposed for sludge minimization, the thermophilic membrane reactor (TMR), operating with alternate aeration/non-aeration cycles. This technology, which has proven to be extremely resilient and suitable for treating industrial wastewater of different nature, demonstrated a high potential also as a solution for integrating existing WWTPs, aiming at the "zero sludge production." In this work, an experimental study was conducted with a TMR pilot plant (fed daily with thickened sewage sludge) by adjusting the duration of aeration/non-aeration alternate cycles. Extracellular polymeric substance (EPS) concentration (and its soluble and bound fractions) has been monitored along with foaming power indices. The results highlight that foaming can be correlated to the presence of soluble protein fraction of EPS. Moreover, EPS production seems to be reduced by increasing the duration of the non-aeration cycles: optimal operating conditions resulted 2 h of aeration followed by 6 h of non-aeration. These conditions allow to obtain an EPS concentration of 500 mg L(-1) with respect to 2300 mg L(-1) measured at the beginning of experimental work.

  20. Sludge dewatering and conveying equipment expands wastewater treatment capabilities to solve refinery's oily waste problem

    SciTech Connect

    Klein, C.; Matlock, M.

    1986-09-01

    Twenty-four years ago, the Sun Refining and Marketing Company refinery in Tulsa, OK installed a large water collection basin to capture storm runoff. Since that time, the refinery has increased its daily capacity to 92,000 bbl - including 52,000 bbl of automotive fuels, 8000 bbl of lubricants, 23,000 bbl of heating oils and LPG products, 200 tons of petro-chemicals, and 110 tons of waxes - to become Oklahoma's second largest refinery. The expansion, coupled with gradual filling of the compartmentalized basin with sludges, required remedial action. In May, 1984, the oil laden basins caught fire. The flames, easily seen from downtown Tulsa (just across the river), were visible from a distance of approximately ten miles. At this point, there was an estimated 16 million gallons of oil sludge present in the 18 million gallon capacity basin complex. Composition was about 20% solids, 10% oil, and 70% water. The EPA immediately issued a cleanup order for the basins; Sun management responded quickly. Replacement of the original sludge treatment equipment, which was both old (installed in the mid-1940s) and too small to handle Sun's subsequent expansion, centered around two highly specialized continuous pressure belt filters and a three dimensional, 85' continuous path sludge transport conveyor. Oily waste from the collection basins is filtered and pumped to the new dewatering facility after an auger-equipped barge churns it into material suitable for pumping. The dewatering facility constructed for the cleanup operations will become the refinery's new sludge treatment plant and will replace the present facility that has been operating since 1945, giving the 73 year old refinery one of the most modern wastewater treatment plants of its type in the industry.

  1. Previously unclassified bacteria dominate during thermophilic and mesophilic anaerobic pre-treatment of primary sludge.

    PubMed

    Pervin, Hasina M; Batstone, Damien J; Bond, Philip L

    2013-06-01

    Thermophilic biological pre-treatment enables enhanced anaerobic digestion for treatment of wastewater sludges but, at present, there is limited understanding of the hydrolytic-acidogenic microbial composition and its contribution to this process. In this study, the process was assessed by comparing the microbiology of thermophilic (50-65 °C) and mesophilic (35 °C) pre-treatment reactors treating primary sludge. A full-cycle approach for the 16S rRNA genes was applied in order to monitor the diversity of bacteria and their abundance in a thermophilic pre-treatment reactor treating primary sludge. For the thermophilic pre-treatment (TP), over 90% of the sequences were previously undetected and these had less than 97% sequence similarity to cultured organisms. During the first 83 days, members of the Betaproteobacteria dominated the community sequences and a newly designed probe was used to monitor a previously unknown bacterium affiliated with the genus Brachymonas. Between days 85 and 183, three phylotypes that affiliated with the genera Comamonas, Clostridium and Lysobacter were persistently dominant in the TP community, as revealed by terminal-restriction fragment length polymorphism (T-RFLP). Hydrolytic and fermentative functions have been speculated for these bacteria. Mesophilic pre-treatment (MP) and TP communities were different but they were both relatively dynamic. Statistical correlation analysis and the function of closely allied reference organisms indicated that previously unclassified bacteria dominated the TP community and may have been functionally involved in the enhanced hydrolytic performance of thermophilic anaerobic pre-treatment. This study is the first to reveal the diversity and dynamics of bacteria during anaerobic digestion of primary sludge.

  2. Partitioning, persistence, and accumulation in digested sludge of the topical antiseptic triclocarban during wastewater treatment.

    PubMed

    Heidler, Jochen; Sapkota, Amir; Halden, Rolf U

    2006-06-01

    The topical antiseptic agent triclocarban (TCC) is a common additive in many antimicrobial household consumables, including soaps and other personal care products. Long-term usage of the mass-produced compound and a lack of understanding of its fate during sewage treatment motivated the present mass balance analysis conducted at a typical U.S. activated sludge wastewater treatment plant featuring a design capacity of 680 million liters per day. Using automated samplers and grab sampling, the mass of TCC contained in influent, effluent, and digested sludge was monitored by isotope dilution liquid chromatography (tandem) mass spectrometry. The average mass of TCC (mean +/- standard deviation) entering and exiting the plant in influent (6.1 +/- 2.0 microg/L) and effluent (0.17 +/- 0.03 microg/ L) was 3737 +/- 694 and 127 +/- 6 g/d, respectively, indicating an aqueous-phase removal efficiency of 97 +/- 1%. Tertiary treatment by chlorination and sand filtration provided no detectable benefit to the overall removal. Due to strong sorption of TCC to wastewater particulate matter (78 +/- 11% sorbed), the majority of the TCC mass was sequestered into sludge in the primary and secondary clarifiers of the plant. Anaerobic digestion for 19 days did not promote TCC transformation, resulting in an accumulation of the antiseptic compound in dewatered, digested municipal sludge to levels of 51 +/- 15 mg/kg dry weight (2815 +/- 917 g/d). In addition to the biocide mass passing through the plant contained in the effluent (3 +/- 1%), 76 +/- 30% of the TCC input entering the plant underwent no net transformation and instead partitioned into and accumulated in municipal sludge. Based on the rate of beneficial reuse of sludge produced by this facility (95%), which exceeds the national average (63%), study results suggest that approximately three-quarters of the mass of TCC disposed of by consumers in the sewershed of the plant ultimately is released into the environment by application

  3. Treatment of industrial effluents by a continuous system: electrocoagulation--activated sludge.

    PubMed

    Moisés, Tejocote-Pérez; Patricia, Balderas-Hernández; Barrera-Díaz, C E; Gabriela, Roa-Morales; Natividad-Rangel, Reyna

    2010-10-01

    A continuous system electrocoagulation--active sludge was designed and built for the treatment of industrial wastewater. The system included an electrochemical reactor with aluminum electrodes, a clarifier and a biological reactor. The electrochemical reactor was tested under different flowrates (50, 100 and 200 mL/min). In the biological reactor, the performance of different cultures of active sludge was assessed: coliform bacterial, ciliate and flagellate protozoa and aquatic fungus. Overall treatment efficiencies of color, turbidity and COD removal were 94%, 92% and 80%, respectively, under optimal conditions of 50 mL/min flowrate and using ciliate and flagellate protozoa. It was concluded that the system was efficient for the treatment of industrial wastewater.

  4. Treatment of biomass gasification wastewater using a combined wet air oxidation/activated sludge process

    SciTech Connect

    English, C.J.; Petty, S.E.; Sklarew, D.S.

    1983-02-01

    A lab-scale treatability study for using thermal and biological oxidation to treat a biomass gasification wastewater (BGW) having a chemical oxygen demand (COD) of 46,000 mg/l is described. Wet air oxidation (WA0) at 300/sup 0/C and 13.8 MPa (2000 psi) was used to initially treat the BGW and resulted in a COD reduction of 74%. This was followed by conventional activated sludge treatment using operating conditions typical of municipal sewage treatment plants. This resulted in an additional 95% COD removal. Overall COD reduction for the combined process was 99%. A detailed chemical analysis of the raw BGW and thermal and biological effluents was performed using gas chromatography/mass spectrometry (GC/MS). These results showed a 97% decrease in total extractable organics with WA0 and a 99.6% decrease for combined WA0 and activated sludge treatment. Components of the treated waters tended to be fewer in number and more highly oxidized. An experiment was conducted to determine the amount of COD reduction caused by volatilization during biological treatment. Unfortunately, this did not yield conclusive results. Treatment of BGW using WA0 followed by activated sludge appears to be very effective and investigations at a larger scale are recommended.

  5. Development of biological process with pure bacterial cultures for effective bioconversion of sewage treatment plant sludge.

    PubMed

    Alam, Zahangir; Muyibi, Suleyman A; Jamal, Parveen

    2007-02-15

    Forty-six bacterial strains were isolated from nine different sources in four treatment plants namely Indah Water Konsortium (IWK) sewage treatment plant (STP), International Islamic University Malaysia (IIUM) wastewater treatment plant-1,-2 and -3 to evaluate the bioconversion process in terms of efficient biodegradation and bioseparation. The bacterial strains isolated were found to be 52.2% (24 isolates) and 47.8% (22 isolates) in the IWK and IIUM treatment plants, respectively. The results showed that higher microbial population (9-10 x 10(4) cfu/mL) was observed in the secondary clarifier of IWK treatment plant. Among the isolates, 23 isolates were gram-positive bacillus (GPB) and gram-positive cocci (GPC), 19 isolates were gram-negative bacillus (GNB) and gram-negative cocci (GNC), and the rest were undetermined. Gram-negative cocci (GNC) were not found in the isolates from IWK. A total of 15 bacterial strains were selected for effective and efficient sludge bioconversion. All the strains were tested against sludge (1% total suspended solids, TSS) to evaluate the biosolids production (TSS% content), chemical oxygen demand (COD) removal and filtration rate (filterability test). The strain S-1 (IWK1001) showed lower TSS content (0.8% TSS), maximum COD removal (84%) and increased filterability (1.1 min/10 mL of filtrate) of treated sludge followed by the strains S-11, S-14, S-2, S-15, S-13, S-7, S-8, S-4, S-3, S-6, S-12, S-16, S-17 and S-9. The pH values in the fermentation broth were affected by the bacterial cultures and recorded as well. Effective bioconversion was observed during the first three days of sludge treatment.

  6. Test Plan: Sludge Treatment Project Corrosion Process Chemistry Follow-on Testing

    SciTech Connect

    Delegard, Calvin H.; Schmidt, Andrew J.; Poloski, Adam P.

    2007-08-17

    This test plan was prepared by the Pacific Northwest National Laboratory (PNNL) under contract with Fluor Hanford (FH). The test plan describes the scope and conditions to be used to perform laboratory-scale testing of the Sludge Treatment Project (STP) hydrothermal treatment of K Basin sludge. The STP, managed for the U. S. Department of Energy (DOE) by FH, was created to design and operate a process to eliminate uranium metal from the sludge prior to packaging for Waste Isolation Pilot Plant (WIPP) by using high temperature liquid water to accelerate the reaction, produce uranium dioxide from the uranium metal, and safely discharge the hydrogen. The proposed testing builds on the approach and laboratory test findings for both K Basin sludge and simulated sludge garnered during prior testing from September 2006 to March 2007. The outlined testing in this plan is designed to yield further understanding of the nature of the chemical reactions, the effects of compositional and process variations and the effectiveness of various strategies to mitigate the observed high shear strength phenomenon observed during the prior testing. These tests are designed to provide process validation and refinement vs. process development and design input. The expected outcome is to establish a level of understanding of the chemistry such that successful operating strategies and parameters can be implemented within the confines of the existing STP corrosion vessel design. In July 2007, the DOE provided direction to FH regarding significant changes to the scope of the overall STP. As a result of the changes, FH directed PNNL to stop work on most of the planned activities covered in this test plan. Therefore, it is unlikely the testing described here will be performed. However, to preserve the test strategy and details developed to date, the test plan has been published.

  7. The fate of a nitrobenzene-degrading bacterium in pharmaceutical wastewater treatment sludge.

    PubMed

    Ren, Yuan; Yang, Juan; Chen, Shaoyi

    2015-12-01

    This paper describes the fate of a nitrobenzene-degrading bacterium, Klebsiella oxytoca NBA-1, which was isolated from a pharmaceutical wastewater treatment facility. The 90-day survivability of strain NBA-1 after exposure to sludge under anaerobic and aerobic conditions was investigated. The bacterium was inoculated into sludge amended with glucose and p-chloronitrobenzene (p-CNB) to compare the bacterial community variations between the modified sludge and nitrobenzene amendment. The results showed that glucose had no obvious effect on nitrobenzene biodegradation in the co-metabolism process, regardless of the presence/absence of oxygen. When p-CNB was added under anaerobic conditions, the biodegradation rate of nitrobenzene remained unchanged although p-CNB inhibited the production of aniline. The diversity of the microbial community increased and NBA-1 continued to be one of the dominant strains. Under aerobic conditions, the degradation rate of both nitrobenzene and p-CNB was only 20% of that under anaerobic conditions. p-CNB had a toxic effect on the microorganisms in the sludge so that most of the DGGE (denaturing gradient gel electrophoresis) bands, including that of NBA-1, began to disappear under aerobic conditions after 90days of exposure. These data show that the bacterial community was stable under anaerobic conditions and the microorganisms, including NBA-1, were more resistant to the adverse environment.

  8. Feasibility studies on the treatment of dairy wastewaters with upflow anaerobic sludge blanket reactors.

    PubMed

    Ramasamy, E V; Gajalakshmi, S; Sanjeevi, R; Jithesh, M N; Abbasi, S A

    2004-06-01

    The feasibility of using upflow anaerobic sludge blanket (UASB) reactors for the treatment of dairy wastewaters was explored. Two types of UASBs were used--one operating on anaerobic sludge granules developed by us from digested cowdung slurry (DCDS) and the other on the granules obtained from the reactors of M/s EID Parry treating sugar industry wastewaters. The reactors were operated at HRT of 3 and 12 h and on COD loading rates ranging from 2.4 kg per m3 of digester volume, per day to 13.5 kg m(-3) d(-1). At the 3 h HRT, the maximum COD reduction in the DCDS-seeded and the industrial sludge-seeded reactors was 95.6% and 96.3%, respectively, better than at 12 h HRT (90% and 92%, respectively). In both the reactors, the maximum, the second best, and the third best COD reduction occurred at the loading rates of 10.8, 8.6 and 7.2 kg m3 d(-1), respectively. At loading rates higher than 10.8 kg, the reactor performance dropped precipitously. Whereas in the first few months the reactors operating on sludge from EID Parry achieved better biodegradation of the waste, compared to the reactors operated on DCDS, the performance of the latter gradually improved and matched with the performance of the former.

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

    PubMed

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

    2014-07-01

    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.

  10. Heavy metal extraction from PCB wastewater treatment sludge by sulfuric acid.

    PubMed

    Kuan, Yu-Chung; Lee, I-Hsien; Chern, Jia-Ming

    2010-05-15

    Heavy metals contaminated wastewater sludge is classified as hazardous solid waste and needs to be properly treated to prevent releasing heavy metals to the environment. In this study, the wastewater treatment sludge from a printed circuit board manufacturing plant was treated in a batch reactor by sulfuric acid to remove the contained heavy metals. The effects of sulfuric acid concentration and solid to liquid ratio on the heavy metal removal efficiencies were investigated. The experimental results showed that the total and individual heavy metal removal efficiencies increased with increasing sulfuric acid concentration, but decreased with increasing solid to liquid ratio. A mathematical model was developed to predict the residual sludge weights at varying sulfuric concentrations and solid to liquid ratios. The trivalent heavy metal ions, iron and chromium were more difficult to be removed than the divalent ions, copper, zinc, nickel, and cadmium. For 5 g/L solid to liquid ratio, more than 99.9% of heavy metals can be removed from the sludge by treating with 0.5M sulfuric acid in 2h.

  11. Chemical removal and recovery of phosphorus from excess sludge in a sewage treatment plant.

    PubMed

    Kato, K; Murotani, N; Matsufuji, H; Saitoh, M; Tashiro, Y

    2006-05-01

    We describe a process for the recovery of phosphorus from excess sludge in a sewage treatment plant that currently uses polyaluminium chloride for chemical phosphorus removal. Instead, we employed alkaline dissolution of excess sludge with calcium phosphate precipitation to recover phosphorus from sewage. The recovery ratio for phosphorus from sewage using the phosphorus recovery system is approximately 50%. In addition, the amount of excess sludge in the phosphorus recovery system is approximately half that of conventional chemical phosphorus removal. Alkaline dissolution of excess sludge resulted in dissolution of aluminium into the supernatant. Furthermore, since dissolved aluminium can be reused as a coagulant, the phosphorus recovery system could be used to economize coagulant consumption. Operation and maintenance costs of the phosphorus recovery system are 25.9 U.S. cents per 1 m3 of sewage compared to 32.0 U.S. cents per 1 m3 of sewage for conventional chemical phosphorus removal, representing a decrease of 20% in the operation and maintenance costs.

  12. Advances in paediatric cancer treatment.

    PubMed

    Saletta, Federica; Seng, Michaela S; Lau, Loretta M S

    2014-04-01

    Four out of five children diagnosed with cancer can be cured with contemporary cancer therapy. This represents a dramatic improvement since 50 years ago when the cure rate of childhood cancer was <25% in the pre-chemotherapy era. Over the past ten years, while improvement in overall survival (OS) has been marginal, progress in pediatric oncology lies with adopting risk-adapted therapeutic approach. This has been made possible through identifying clinical and biologic prognostic factors with rigorous research and stratifying patients using these risk factors, and subsequently modifying therapy according to risk group assignment. This review provides a perspective for eight distinct pediatric malignancies, in which significant advances in treatment were made in the last decade and are leading to changes in standard of care. This includes four hematologic malignancies [acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL)] and four solid tumors [medulloblastoma (MB), low grade glioma (LGG), neuroblastoma (NB) and Ewing sarcoma (ES)]. Together, they comprise 60% of childhood cancer. Improved patient outcome is not limited to better survival, but encompasses reducing both short and long-term treatment-related complications which is as important as cure, given the majority of childhood cancer patients will become long-term survivors. Risk-adapted approach allows treatment intensification in the high-risk cohort while therapy can be de-escalated in the low-risk to minimize toxicity and late sequelae without compromising survival. Advances in medical research technology have also led to a rapid increase in the understanding of the genetics of childhood cancer in the last decade, facilitating identification of molecular targets that can potentially be exploited for therapeutic benefits. As we move into the era of targeted therapeutics, searching for novel agents that target specific genetic lesions becomes a

  13. Addition of Al and Fe salts during treatment of paper mill effluents to improve activated sludge settlement characteristics.

    PubMed

    Agridiotis, V; Forster, C F; Carliell-Marquet, C

    2007-11-01

    Metal salts, ferrous sulphate and aluminium chloride, were added to laboratory-scale activated sludge plant treating paper mill effluents to investigate the effect on settlement characteristics. Before treatment the sludge was filamentous, had stirred sludge volume index (SSVI) values in excess of 300 and was moderately hydrophobic. The use of FeSO4.7H2O took three weeks to reduce the SSVI to 90. Microscopic examination showed that Fe had converted the filamentous flocs into a compact structure. When the iron dosing was stopped, the sludge returned to its bulking state within four weeks. In a subsequent trial, the addition of AlCl3 initially resulted in an improvement of the settlement index but then caused deterioration of the sludge properties. It is possible that aluminium was overdosed and caused charge reversal, increasing the SSVI.

  14. Land Application of Treated Sewage Sludge in the United States: Regulatory Considerations for Risk Reduction and Determining Treatment Process Equivalency

    EPA Science Inventory

    In the United States, municipal wastewater includes discharges from households, commercial businesses and various industries. Microorganisms associated with these wastes can be concentrated in the solids (sludge) which are removed during treatment operations. Beneficial reuse a...

  15. Mineralization behavior of fluorine in perfluorooctanesulfonate (PFOS) during thermal treatment of lime-conditioned sludge.

    PubMed

    Wang, Fei; Shih, Kaimin; Lu, Xingwen; Liu, Chengshuai

    2013-03-19

    The fate and transport of the fluorine in perfluorooctanesulfonate (PFOS) during the thermal treatment of lime-conditioned sludge were observed using both qualitative and quantitative X-ray diffraction techniques. Two main fluorine mineralization mechanisms leading to the substantial formation of CaF2 and Ca5(PO4)3F phases were observed. They had a close relationship with the thermal treatment condition and the PFOS content of the sludge. At low temperatures (300-600 °C), CaF2 dominated in the product and increases in treatment time and temperature generally enhanced the fluorine transformation. However, at higher temperatures (700-900 °C), increases in treatment time and temperature had a negative effect on the overall efficiency of the fluorine crystallization. The results suggest that in the high temperature environment there were greater losses of gaseous products such as HF and SiF4 in the transformation of CaF2 to Ca5(PO4)3F, the hydrolysis of CaF2, and the reaction with SiO2. The quantitative analysis also showed that when treating sludge with low PFOS content at high temperatures, the formation of Ca5(PO4)3F may be the primary mechanism for the mineralization of the fluorine in PFOS. The overall results clearly indicate the variations in the fate and transport of fluorine in PFOS when the sludge is subject to different PFOS contents and treatment types, such as heat drying or incineration.

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

    PubMed Central

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

    2014-01-01

    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

  17. Integration of aerobic granular sludge and mesh filter membrane bioreactor for cost-effective wastewater treatment.

    PubMed

    Li, Wen-Wei; Wang, Yun-Kun; Sheng, Guo-Ping; Gui, Yong-Xin; Yu, Lei; Xie, Tong-Qing; Yu, Han-Qing

    2012-10-01

    Conventional MBR has been mostly based on floc sludge and the use of costly microfiltration membranes. Here, a novel aerobic granule (AG)-mesh filter MBR (MMBR) process was developed for cost-effective wastewater treatment. During 32-day continuous operation, a predominance of granules was maintained in the system, and good filtration performance was achieved at a low trans-membrane pressure (TMP) of below 0.025 m. The granules showed a lower fouling propensity than sludge flocs, attributed to the formation of more porous biocake layer at mesh surface. A low-flux and low-TMP filtration favored a stable system operation. In addition, the reactor had high pollutant removal efficiencies, with a 91.4% chemical oxygen demand removal, 95.7% NH(4)(+) removal, and a low effluent turbidity of 4.1 NTU at the stable stage. This AG-MMBR process offers a promising technology for low-cost and efficient treatment of wastewaters.

  18. Recovery and reuse of sludge from active and passive treatment of mine drainage-impacted waters: a review.

    PubMed

    Rakotonimaro, Tsiverihasina V; Neculita, Carmen Mihaela; Bussière, Bruno; Benzaazoua, Mostafa; Zagury, Gérald J

    2017-01-01

    The treatment of mine drainage-impacted waters generates considerable amounts of sludge, which raises several concerns, such as storage and disposal, stability, and potential social and environmental impacts. To alleviate the storage and management costs, as well as to give the mine sludge a second life, recovery and reuse have recently become interesting options. In this review, different recovery and reuse options of sludge originating from active and passive treatment of mine drainage are identified and thoroughly discussed, based on available laboratory and field studies. The most valuable products presently recovered from the mine sludge are the iron oxy-hydroxides (ochre). Other by-products include metals, elemental sulfur, and calcium carbonate. Mine sludge reuse includes the removal of contaminants, such as As, P, dye, and rare earth elements. Mine sludge can also be reused as stabilizer for contaminated soil, as fertilizer in agriculture/horticulture, as substitute material in construction, as cover over tailings for acid mine drainage prevention and control, as material to sequester carbon dioxide, and in cement and pigment industries. The review also stresses out some of the current challenges and research needs. Finally, in order to move forward, studies are needed to better estimate the contribution of sludge recovery/reuse to the overall costs of mine water treatment.

  19. Treatment of sludge containing nitro-aromatic compounds in reed-bed mesocosms - Water, BOD, carbon and nutrient removal

    SciTech Connect

    Gustavsson, L.; Engwall, M.

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer It is necessary to improve existing and develop new sludge management techniques. Black-Right-Pointing-Pointer One method is dewatering and biodegradation of compounds in constructed wetlands. Black-Right-Pointing-Pointer The result showed high reduction of all tested parameters after treatment. Black-Right-Pointing-Pointer Plants improve degradation and Phragmites australis is tolerant to xenobiotics. Black-Right-Pointing-Pointer The amount of sludge could be reduced by 50-70%. - Abstract: Since the mid-1970s, Sweden has been depositing 1 million ton d.w sludge/year, produced at waste water treatment plants. Due to recent legislation this practice is no longer a viable method of waste management. It is necessary to improve existing and develop new sludge management techniques and one promising alternative is the dewatering and treatment of sludge in constructed wetlands. The aim of this study was to follow reduction of organic carbon, BOD and nutrients in an industrial sludge containing nitro-aromatic compounds passing through constructed small-scale wetlands, and to investigate any toxic effect such as growth inhibition of the common reed Phragmites australis. The result showed high reduction of all tested parameters in all the outgoing water samples, which shows that constructed wetlands are suitable for carbon and nutrient removal. The results also showed that P. australis is tolerant to xenobiotics and did not appear to be affected by the toxic compounds in the sludge. The sludge residual on the top of the beds contained low levels of organic carbon and is considered non-organic and could therefore be landfilled. Using this type of secondary treatment method, the amount of sludge could be reduced by 50-70%, mainly by dewatering and biodegradation of organic compounds.

  20. Hazard Evaluation for Storage of Spent Nuclear Fuel (SNF) Sludge at the Solid Waste Treatment Facility

    SciTech Connect

    SCHULTZ, M.V.

    2000-08-22

    As part of the Spent Nuclear Fuel (SNF) storage basin clean-up project, sludge that has accumulated in the K Basins due to corrosion of damaged irradiated N Reactor will be loaded into containers and placed in interim storage. The Hanford Site Treatment Complex (T Plant) has been identified as the location where the sludge will be stored until final disposition of the material occurs. Long term storage of sludge from the K Basin fuel storage facilities requires identification and analysis of potential accidents involving sludge storage in T Plant. This report is prepared as the initial step in the safety assurance process described in DOE Order 5480.23, Nuclear Safety Analysis Reports and HNF-PRO-704, Hazards and Accident Analysis Process. This report documents the evaluation of potential hazards and off-normal events associated with sludge storage activities. This information will be used in subsequent safety analyses, design, and operations procedure development to ensure safe storage. The hazards evaluation for the storage of SNF sludge in T-Plant used the Hazards and Operability Analysis (HazOp) method. The hazard evaluation identified 42 potential hazardous conditions. No hazardous conditions involving hazardous/toxic chemical concerns were identified. Of the 42 items identified in the HazOp study, eight were determined to have potential for onsite worker consequences. No items with potential offsite consequences were identified in the HazOp study. Hazardous conditions with potential onsite worker or offsite consequences are candidates for quantitative consequence analysis. The hazardous conditions with potential onsite worker consequences were grouped into two event categories, Container failure due to overpressure - internal to T Plant, and Spill of multiple containers. The two event categories will be developed into accident scenarios that will be quantitatively analyzed to determine release consequences. A third category, Container failure due to

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

    PubMed

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

    2011-04-01

    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.

  2. Phosphorus extraction and sludge dissolution by acid and alkali treatments of polyaluminum chloride (PAC) treated wastewater sludge.

    PubMed

    Ali, Toor Umair; Kim, Dong-Jin

    2016-10-01

    Phosphorus (P) leaching characteristics of polyaluminium chlorides (PAC) treated wastewater sludge was investigated by wet chemicals (acid and alkali). Sludge fractionation showed non-apatite inorganic P was the dominant P (90.9% of TP) while apatite P only accounted for 3.7%. After 2h extraction with 1N NaOH or 2N HCl, 80.5% and 77.9% of total P was leached, while sludge dissolution reached 72.7% and 75.6%, respectively. Kinetic study with HCl and NaOH showed that P release and sludge dissolution follow first order reaction with rate constants of 0.50 and 0.35min(-1) (P release) and 0.47×10(-2) and 0.15×10(-2)min(-1) (sludge dissolution), respectively. Sequential extraction by NaOH/HCl leached 91.7% of the total P. This study will help in understanding the P release behavior of the PAC treated wastewater sludge.

  3. Survival of Bacterial Indicator Species and Bacteriophages after Thermal Treatment of Sludge and Sewage

    PubMed Central

    Mocé-Llivina, Laura; Muniesa, Maite; Pimenta-Vale, Hugo; Lucena, Francisco; Jofre, Juan

    2003-01-01

    The inactivation of naturally occurring bacterial indicators and bacteriophages by thermal treatment of a dewatered sludge and raw sewage was studied. The sludge was heated at 80°C, and the sewage was heated at 60°C. In both cases phages were significantly more resistant to thermal inactivation than bacterial indicators, with the exception of spores of sulfite-reducing clostridia. Somatic coliphages and phages infecting Bacteroides fragilis were significantly more resistant than F-specific RNA phages. Similar trends were observed in sludge and sewage. The effects of thermal treatment on various phages belonging to the three groups mentioned above and on various enteroviruses added to sewage were also studied. The results revealed that the variability in the resistance of phages agreed with the data obtained with the naturally occurring populations and that the phages that were studied were more resistant to heat treatment than the enteroviruses that were studied. The phages survived significantly better than Salmonella choleraesuis, and the extents of inactivation indicated that naturally occurring bacteriophages can be used to monitor the inactivation of Escherichia coli and Salmonella. PMID:12620828

  4. Comparative study of wastewater treatment and nutrient recycle via activated sludge, microalgae and combination systems.

    PubMed

    Wang, Liang; Liu, Jinli; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

    2016-07-01

    Algal-bacterial synergistic cultivation could be an optional wastewater treatment technology in temperate areas. In this study, a locally screened vigorous Chlorella strain was characterized and then it was used in a comparative study of wastewater treatment and nutrient recycle assessment via activated sludge (AS), microalgae and their combination systems. Chlorella sp. cultured with AS in light showed the best performance, in which case the removal efficiencies of COD, NH3-N and TP were 87.3%, 99.2% and 83.9%, respectively, within a short period of 1day. Algal-bacterial combination in light had the best settleability. Chlorella sp. contained biomass, could be processed to feed, fertilizer or fuel due to the improved quality (higher C/H/N) compared with sludge. PCR-DGGE analysis shows that two types of rhizobacteria, namely, Pseudomonas putida and Flavobacterium hauense were enriched in sludge when cultured with algae in light, serving as the basics for artificial consortium construction for improved wastewater treatment.

  5. Reuse of drinking water treatment sludge for olive oil mill wastewater treatment.

    PubMed

    Fragoso, R A; Duarte, E A

    2012-01-01

    Olive mill wastewater (OMW) results from the production of olive oil, which is an important traditional agro-industry in Mediterranean countries. In continuous three-phase centrifugation 1.0-1.2 m(3) of OMW are produced per ton of processed olives. Discharge of OMW is of serious environmental concern due to its high content of organic matter with phytotoxic properties, namely phenolic compounds. Meanwhile, drinking water treatment sludge (DWTS) is produced in high amounts and has long been considered as a waste for landfill. The aim of this work was the assessment of reusing DWTS for OMW treatment. High performance liquid chromatography (HPLC) analysis was carried out to determine the phenolic compounds present and to evaluate if they are recalcitrant. Treatability assays were performed using a dosage of DWTS from 50 to 300 g L(-1). Treatment efficiency was evaluated based on the removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total solids (TS), total suspended solids (TSS), total volatile solids (TVS), oil and grease (OG), phenols (total phosphorous (TP) and HPLC fraction). Results from OMW HPLC characterization identified a total of 13 compounds; the major ones were hydroxytyrosol, tyrosol, caffeic acid, p-cumaric acid and oleuropein. Treatability assays led to a maximum reduction of about 90% of some of the phenolic compounds determined by HPLC. Addition of 200-300 g L(-1) of DWTS reduced 40-50% of COD, 45-50% of TP, a maximum of nearly 70% TSS and 45% for TS and TVS. The OG fraction showed a reduction of about 90%, achieved adding 300 g L(-1) od DWTS. This study points out the possibility of establishing an integrated management of OMW and DWTS, contributing to a decrease in the environmental impact of two industrial activities, olive oil production and drinking water treatment.

  6. Bacterial response to a shock load of nanosilver in an activated sludge treatment system.

    PubMed

    Liang, Zhihua; Das, Atreyee; Hu, Zhiqiang

    2010-10-01

    The growing release of nanosilver into sewage systems has increased the concerns on the potential adverse impacts of silver nanoparticles (AgNPs) in wastewater treatment plants. The inhibitory effects of nanosilver on wastewater treatment and the response of activated sludge bacteria to the shock loading of AgNPs were evaluated in a Modified Ludzack-Ettinger (MLE) activated sludge treatment system. Before shock-loading experiments, batch extant respirometric assays determined that at 1mg/L of total Ag, nitrification inhibitions by AgNPs (average size=1-29 nm) and Ag(+) ions were 41.4% and 13.5%, respectively, indicating that nanosilver was more toxic to nitrifying bacteria in activated sludge than silver ions. After a 12-h period of nanosilver shock loading to reach a final peak silver concentration of 0.75 mg/L in the MLE system, the total silver concentration in the mixed liquor decreased exponentially. A continuous flow-through model predicted that the silver in the activated sludge system would be washed out 25 days after the shock loading. Meanwhile, a prolonged period of nitrification inhibition (>1 month, the highest degree of inhibition=46.5%) and increase of ammonia/nitrite concentration in wastewater effluent were observed. However, nanosilver exposure did not affect the growth of heterotrophs responsible for organic matter removal. Microbial community structure analysis indicated that the ammonium-oxidizing bacteria and nitrite-oxidizing bacteria, Nitrospira, had experienced population decrease while Nitrobacter was washed out after the shock loading.

  7. Hydrothermal Liquefaction and Upgrading of Municipal Wastewater Treatment Plant Sludge: A Preliminary Techno-Economic Analysis

    SciTech Connect

    Snowden-Swan, Lesley J.; Zhu, Yunhua; Jones, Susanne B.; Elliott, Douglas C.; Schmidt, Andrew J.; Hallen, Richard T.; Billing, Justin M.; Hart, Todd R.; Fox, Samuel P.; Maupin, Gary D.

    2016-06-08

    A preliminary process model and techno-economic analysis (TEA) was completed for fuel produced from hydrothermal liquefaction (HTL) of sludge waste from a municipal wastewater treatment plant (WWTP) and subsequent biocrude upgrading. The model is adapted from previous work by Jones et al. (2014) for algae HTL, using experimental data generated in fiscal year 2015 (FY15) bench-scale HTL testing of sludge waste streams. Testing was performed on sludge samples received from MetroVancouver’s Annacis Island WWTP (Vancouver, B.C.) as part of a collaborative project with the Water Environment and Reuse Foundation (WERF). The full set of sludge HTL testing data from this effort will be documented in a separate report to be issued by WERF. This analysis is based on limited testing data and therefore should be considered preliminary. Future refinements are necessary to improve the robustness of the model, including a cross-check of modeled biocrude components with the experimental GCMS data and investigation of equipment costs most appropriate at the smaller scales used here. Environmental sustainability metrics analysis is also needed to understand the broader impact of this technology pathway. The base case scenario for the analysis consists of 10 HTL plants, each processing 100 dry U.S. ton/day (92.4 ton/day on a dry, ash-free basis) of sludge waste and producing 234 barrel per stream day (BPSD) biocrude, feeding into a centralized biocrude upgrading facility that produces 2,020 barrel per standard day of final fuel. This scale was chosen based upon initial wastewater treatment plant data collected by the resource assessment team from the EPA’s Clean Watersheds Needs Survey database (EPA 2015a) and a rough estimate of what the potential sludge availability might be within a 100-mile radius. In addition, we received valuable feedback from the wastewater treatment industry as part of the WERF collaboration that helped form the basis for the selected HTL and upgrading

  8. Toxicity of ammonia nitrogen to ciliated protozoa Stentor coeruleus and Coleps hirtus isolated from activated sludge of wastewater treatment plants.

    PubMed

    Klimek, Beata; Fyda, Janusz; Pajdak-Stós, Agnieszka; Kocerba, Wioleta; Fiałkowska, Edyta; Sobczyk, Mateusz

    2012-11-01

    We assessed the toxicity of ammonia ions to Stentor coeruleus and Coleps hirtus (Protozoa) isolated from activated sludge taken from two municipal wastewater treatment plants in southern Poland. Stentor coeruleus is a rarely occurring species in activated sludge, unlike the widespread Coleps hirtus. The mean LC50 values (concentration causing 50 % mortality) calculated for the 24 h tests differed hugely between the tested species: 43.03 mg NH(4+) dm(-3) for Stentor coeruleus and 441.12 mg NH(4+) dm(-3) for Coleps hirtus. The ammonia ion concentration apparently is an important factor in the occurrence of these protozoan species in activated sludge.

  9. Optimization of the preparation conditions of ceramic products using drinking water treatment sludges.

    PubMed

    Zamora, R M Ramirez; Ayala, F Espesel; Garcia, L Chavez; Moreno, A Duran; Schouwenaars, R

    2008-11-01

    The aim of this work is to optimize, via Response Surface Methodology, the values of the main process parameters for the production of ceramic products using sludges obtained from drinking water treatment in order to valorise them. In the first experimental stage, sludges were collected from a drinking water treatment plant for characterization. In the second stage, trials were carried out to elaborate thin cross-section specimens and fired bricks following an orthogonal central composite design of experiments with three factors (sludge composition, grain size and firing temperature) and five levels. The optimization parameters (Y(1)=shrinking by firing (%), Y(2)=water absorption (%), Y(3)=density (g/cm(3)) and Y(4)=compressive strength (kg/cm(2))) were determined according to standardized analytical methods. Two distinct physicochemical processes were active during firing at different conditions in the experimental design, preventing the determination of a full response surface, which would allow direct optimization of production parameters. Nevertheless, the temperature range for the production of classical red brick was closely delimitated by the results; above this temperature, a lightweight ceramic with surprisingly high strength was produced, opening possibilities for the valorisation of a product with considerably higher added value than what was originally envisioned.

  10. Occurrence of organotins in municipal wastewater and sewage sludge and behavior in a treatment plant

    SciTech Connect

    Fent, K. ); Mueller, M.D. )

    1991-03-01

    THe behavior of selected organotin species in a wastewater treatment plant of Zurich, Switzerland, was studied. In untreated wastewater, monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were detected in the range of 136-564, 127-1,026, and 64-217 ng/L, respectively, of which 81-92% were associated with suspended solids. During treatment, the fraction of organotins in the particulate phase decreased with decreasing suspended solids concentration. All organotin species monitored were found to be efficiently removed from wastewater, mainly by sedimentation in the primary clarifier. In the secondary effluent, levels of different organotins were in the range of 7-47 ng/L. These compounds were transferred into sewage sludge, indicating that the most important process for the elimination of organotins was adsorption into sludge. Residues of MBT, DBT, and TBT in digested sludges were in the range of 0.10-0.97, 0.41-1.24, and 0.28-1.51 mg/kg (dry weight), respectively.

  11. Effect of aluminium and sulphate on anaerobic digestion of sludge from wastewater enhanced primary treatment.

    PubMed

    Cabirol, N; Barragán, E J; Durán, A; Noyola, A

    2003-01-01

    The combined and individual effects of aluminium and sulphate at concentrations of 1,000 mg/l as Al(OH)3, and 150 mgSO4(2-)/L as K2SO4, respectively, on the anaerobic digestion of sludge from enhanced primary treatment (EPT) were evaluated in 1 L capacity semi continuous reactors. It was found that at 59 days, aluminium inhibits the specific methanogenic activity (SMA) of methanogenic and acetogenic bacteria resulting in a 50% to 72% decrease. Sulphate also inhibits (48% to 65%) the SMA of the same type of bacteria. Methanogenic and acetogenic bacteria were able to adapt, to a different extent, to the assayed concentrations of aluminium and sulphate. However, the combination of aluminium and sulphate resulted in a higher inhibition, especially of the hydrogenophilic methanogenic bacteria. Indeed, this effect remained during the time of the experiment, maintaining an inhibition of 44% at 114 days. Feeding with EPT sludge led to a bigger decrease in SMA of each bacterial group, with respect to the other treatments with time. It is concluded that the acidification of anaerobic reactors fed with EPT sludge is due, among other causes, to the concurrent presence of aluminium and sulphate.

  12. Effect of earthworms on the biochemical characterization of biofilms in vermifiltration treatment of excess sludge.

    PubMed

    Yang, Jian; Liu, Jing; Xing, Meiyan; Lu, Zhibo; Yan, Qiong

    2013-09-01

    In this study, the biofilms formed in a vermifilter (VF) with earthworms and a conventional biofilter (BF) without earthworms were compared to investigate the effects of earthworms on the characteristics of biofilms during an excess sludge treatment period of 4months. Typical macrographs and micrographs of the biofilms showed that the feeding and casting actions of earthworms remarkably modified the VF morphology. Elemental analysis and fluorescence spectra indicated that earthworms enhanced the stabilization of organic matter by accelerating the mineralization and humification of organic materials during vermiconversion. In addition, bacterial communities inhabiting the VF biofilm showed that earthworms increased both bacterial diversity and metabolic activities in the film, as revealed by automatic testing bacteriology (ATB) expression and sequencing data. These results demonstrate that earthworms influence the structure and biochemical characteristics of biofilms and enhance their bacterial diversity and functions for improved sludge stabilization.

  13. Helminth eggs in the sludge from three sewage treatment plants in Czechoslovakia.

    PubMed

    Horák, P

    1992-01-01

    Developmental stages of 8 species of parasitic helminths were found during examination of sludge from 3 sewage treatment plants in Central Bohemia, Czechoslovakia. The eggs were comprised from Ascaris sp., Toxocara sp., Toxascaris leonina, Parascaris equorum, Enterobius vermicularis, Trichuris sp., Capillaria sp. and Hymenolepis spp. The quantity of these organisms in 100 g of dried sludge ranged between 24-105 eggs of Ascaris sp., 12-47 eggs of Toxocara sp., 0-8 eggs of Toxascaris leonina, 0-1 egg of Parascaris equorum, 2-33 eggs of Trichuris sp., 0-12 eggs of Capillaria sp., 0-46 eggs of Enterobius vermicularis and 0-49 eggs of Hymenolepis spp. Some eggs of Hymenolepis spp. and Enterobius vermicularis were structurally damaged, while some eggs of Ascaris sp. and Enterobius vermicularis contained developed larvae.

  14. Influence of thermal treatment on sequential extraction and leaching behaviour of trace metals in a contaminated sewage sludge.

    PubMed

    Obrador, A; Rico, M I; Alvarez, J M; Novillo, J

    2001-02-01

    The losses of weight and organic matter of a sludge caused by thermal treatments at 180 degrees C, 300 degrees C and 400 degrees C were determined in order to assess how the possibilities of sludge use were influenced. The sludge heated at 180 degrees C lost small amounts of weight and organic matter (9.8%) but the losses from the two other treatments were large enough (92.2% and 99.9% in organic matter) to preclude the use of the sludges as organic amendments. The concentration and potential lability and leachability of Cr, Cu, Fe, Mn, Ni, Pb and Zn in the native sludge and in the thermal-treated sludge samples were studied by means of a five-step chemical fractionation method and a column experiment. As a consequence of heating, the trace metals were more strongly fixed in the treated sludges, as could be seen by the decrease with temperature of the ratio between the sum of the first two sequential-extracted fractions and the residual fraction. The leaching results showed that, for the native sludge, the quantities of studied metals leached were larger than for the sludge heated to 180 degrees C. The order of leachability of metals was the same in both cases, and the same equation could be used to calculate the quantities of metals leached. The amounts of metals leached correlated significantly with the first extracted fraction (exchangeable metals) and an equation could be used to calculate the quantities leached, as a function of that fraction.

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

    PubMed

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

    2014-10-01

    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 μg L(-1) for influent and 0.08 μg 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 μg 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).

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  17. Metals distributions in activated sludge systems

    SciTech Connect

    Patterson, J.W.; Kodukula, P.S.

    1984-05-01

    Despite extensive laboratory and field studies over the past 25 years, little advance has been made in prediction of metals distribution and removal in activated sludge treatment systems. This paper reports the results of carefully controlled pilot studies, from which empirical metals distribution models were developed. The models accurately predict the distribution of process stream metals at each point in the activated sludge process between the soluble and solids phases. The distribution models together with data on primary and secondary clarifier suspended solids removal efficiencies, are easily applied to predict the removals of influent metals in activated sludge systems. 36 references, 2 figures.

  18. Dynamics of the microfauna community in a full-scale municipal wastewater treatment plant experiencing sludge bulking.

    PubMed

    Hu, Bo; Qi, Rong; An, Wei; Xu, Muqi; Zhang, Yu; Bai, Xue; Bao, Haipeng; Wen, Yang; Gu, Jian; Yang, Min

    2013-11-01

    We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SVI) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.

  19. Hybrid life-cycle environmental and cost inventory of sewage sludge treatment and end-use scenarios: a case study from China.

    PubMed

    Murray, Ashley; Horvath, Arpad; Nelson, Kara L

    2008-05-01

    Sewage sludge management poses environmental, economic, and political challenges for wastewater treatment plants and municipalities around the globe. To facilitate more informed and sustainable decision making, this study used life-cycle inventory (LCI) to expand upon previous process-based LCIs of sewage sludge treatmenttechnologies. Additionally, the study evaluated an array of productive end-use options for treated sewage sludge, such as fertilizer and as an input into construction materials, to determine how the sustainability of traditional manufacturing processes changes with sludge as a replacement for other raw inputs. The inclusion of the life-cycle of necessary inputs (such as lime) used in sludge treatment significantly impacts the sustainability profiles of different treatment and end-use schemes. Overall, anaerobic digestion is generally the optimal treatment technology whereas incineration, particularly if coal-fired, is the most environmentally and economically costly. With respect to sludge end use, offsets are greatest for the use of sludge as fertilizer, but all of the productive uses of sludge can improve the sustainability of conventional manufacturing practices. The results are intended to help inform and guide decisions about sludge handling for existing wastewater treatment plants and those that are still in the planning phase in cities around the world. Although additional factors must be considered when selecting a sludge treatment and end-use scheme, this study highlights how a systems approach to planning can contribute significantly to improving overall environmental sustainability.

  20. Innovative sludge stabilization method

    SciTech Connect

    Riggenbach, J.D.

    1995-06-01

    Sludge is generated in many water and wastewater treatment processes, both biological and physical/chemical. Examples include biological sludges from sanitary and industrial wastewater treatment operations and chemical sludges such as those produced when metals are removed from metal plating wastewater. Even some potable water plants produce sludge, such as when alum is used as a flocculating agent to clarify turbid water. Because sludge is produced from such a variety of operations, different techniques have been developed to remove water from sludges and reduce the sludge volume and mass, thus making the sludge more suitable for recovery or disposal. These techniques include mechanical (e.g., filter presses), solar (sludge drying beds), and thermal. The least expensive of these methods, neglecting land costs, involves sludge drying beds and lagoons. The solar method was widely used in sewage treatment plants for many years, but has fallen in disfavor in the US; mechanical and thermal methods have been preferred. Since environmental remediation often requires managing sludges, this article presents a discussion of a variation of sludge lagoons known as evaporative sludge stabilization. Application of this process to the closure of two 2.5 acre (10117 m{sup 2}) hazardous waste surface impoundments will be discussed. 1 ref., 2 figs.

  1. Selective release of phosphorus and nitrogen from waste activated sludge with combined thermal and alkali treatment.

    PubMed

    Kim, Minwook; Han, Dong-Woo; Kim, Dong-Jin

    2015-08-01

    Selective release characteristics of phosphorus and nitrogen from waste activated sludge (WAS) were investigated during combined thermal and alkali treatment. Alkali (0.001-1.0N NaOH) treatment and combined thermal-alkali treatment were applied to WAS for releasing total P(T-P) and total nitrogen(T-N). Combined thermal-alkali treatment released 94%, 76%, and 49% of T-P, T-N, and COD, respectively. Release rate was positively associated with NaOH concentration, while temperature gave insignificant effect. The ratio of T-N and COD to T-P that released with alkali treatment ranged 0.74-0.80 and 0.39-0.50, respectively, while combined thermal-alkali treatment gave 0.60-0.90 and 0.20-0.60, respectively. Selective release of T-P and T-N was negatively associated with NaOH. High NaOH concentration created cavities on the surface of WAS, and these cavities accelerated the release rate, but reduced selectivity. Selective release of P and N from sludge has a beneficial effect on nutrient recovery with crystallization processes and it can also enhance methane production.

  2. Fate and behaviour of copper and zinc in secondary biological wastewater treatment processes: II. Removal at varying sludge age.

    PubMed

    Santos, A; Barton, P; Cartmell, E; Coulon, F; Crane, R S; Hillis, P; Lester, J N; Stephenson, T; Judd, S J

    2010-06-01

    The mechanisms for the removal of heavy metals during secondary biological treatment of wastewater, with particular emphasis on the activated sludge process, are considered. It is concluded that the predominant mechanism is the entrapment and co-settlement of insoluble metal species in the mixed liquor (biomass). Secondary extracellular polymeric materials, particularly extracellular polysaccharides and other capsule-forming materials, may also play a role. In general, removal of both copper and zinc was superior at the higher sludge ages employed in this study, 4.3 and 8 days, and can in part be attributed to the superior removals of both biochemical oxygen demand and effluent suspended solids achieved at these sludge ages compared with the lowest sludge age studied, 3.6 days. For both copper and zinc there is an increase in soluble metal across the activated sludge process. However, significant removal of both metals occurs as a consequence of the removal of substantial amounts of insoluble metal. The presence of returned sludge liquors, high in settleable solids, to the mixed liquor appears to moderately enhance the percentage removal of copper and zinc. Membranes used in place of secondary sedimentation also enhance removal of both metals by reducing effluent suspended solids. It is concluded that there is potential for maximizing metal removal by optimization of secondary biological treatment in a sustainable manner, without recourse to energy-intensive or chemically-dependent tertiary treatment technologies.

  3. Primary Treatment and Sludge Digestion Workshop. Second Edition (Revised).

    ERIC Educational Resources Information Center

    Ontario Ministry of the Environment, Toronto.

    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. The body of the text provides content information, procedure outlines,…

  4. Anaerobic Codigestion of Municipal Wastewater Treatment Plant Sludge with Food Waste: A Case Study

    PubMed Central

    Rajendram, William

    2016-01-01

    The aim of this study was to assess the effects of the codigestion of food manufacturing and processing wastes (FW) with sewage sludge (SS), that is, municipal wastewater treatment plant primary sludge and waste activated sludge. Bench scale mesophilic anaerobic reactors were fed intermittently with varying ratio of SS and FW and operated at a hydraulic retention time of 20 days and organic loading of 2.0 kg TS/m3·d. The specific biogas production (SBP) increased by 25% to 50% with the addition of 1%–5% FW to SS which is significantly higher than the SBP from SS of 284 ± 9.7 mLN/g VS added. Although the TS, VS, and tCOD removal slightly increased, the biogas yield and methane content improved significantly and no inhibitory effects were observed as indicated by the stable pH throughout the experiment. Metal screening of the digestate suggested the biosolids meet the guidelines for use as a soil conditioner. Batch biochemical methane potential tests at different ratios of SS : FW were used to determine the optimum ratio using surface model analysis. The results showed that up to 47-48% FW can be codigested with SS. Overall these results confirm that codigestion has great potential in improving the methane yield of SS. PMID:27689091

  5. Aerobic thermophilic treatment of sewage sludge at pilot plant scale. 2. Technical solutions and process design.

    PubMed

    Ponti, C; Sonnleitner, B; Fiechter, A

    1995-01-15

    The performance of the ATS process depends essentially on the oxygen transfer efficiency. Improvement of the mass transfer capacity of a bioreactor allowed to reduce the incubation time necessary to attain sludge stabilization. It is important to use equipment with a high aeration efficiency such as an injector aeration system. The ratio between the total oxygen consumption and the organic matter degradation (delta COD) ranged between 0.4 and 0.8 in the pilot plant, whereas 1.23 was found in completely mixed bioreactors (Bomio, 1990). No significant improvement of the bacterial degradation efficiency was attained with a specific power input exceeding 6-8 kW m-3. A mean residence time of less than 1 d allowed organic matter removals up to 40% with specific power consumption of 10 kWh kg-1 COD oxidized. The sludge hygienization is one of the objectives and benefits of the thermophilic treatment: not only temperature but also the total solids content were important factors affecting inactivation of pathogens. The inactivation rate was promoted by the increase of temperature, while the residual colony forming units decreased with reducing the total solids content of sewage sludge. It is concluded that continuous operation mode would not affect the quality of the hygienization but could display the high degradation potential of the aerobic system.

  6. Characterization of bioflocculants from biologically aerated filter backwashed sludge and its application in dying wastewater treatment.

    PubMed

    Liu, WeiJie; Yuan, HongLi; Yang, JinShui; Li, BaoZhen

    2009-05-01

    In this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.0 had no flocculating activity. In contrast, bioflocculants extracted from sludge of pH 5.0, named as M-1, had good flocculating activity. To further study the flocculating activity of M-1, factors such as bioflocculant dosage, temperature and pH of the reaction solution were tested. The optimal conditions were 6.0mg/l bioflocculant dosage and pH 5.0, at a temperature of 10 degrees C. Under these conditions, the flocculating rate of kaolin clay was 92.67%. The effectiveness of such bioflocculants in the decolorization of synthetically dyed wastewater was then examined. In flocculating methylene blue and fast blue in aqueous solutions, decolorization efficiency levels were 82.9% and 77.8%, respectively.

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

    PubMed

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

    2012-11-15

    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.

  8. [Nutrient contents and heavy metal pollutions in composted sewage sludge from different municipal wastewater treatment plants in Beijing region].

    PubMed

    Bai, Li-Ping; Qi, Hong-Tao; Fu, Ya-Ping; Li, Ping

    2014-12-01

    Changes of nutrient contents and heavy metal pollutions in composted sewage sludge from different municipal wastewater treatment plants (as represented by CSS-A and CSS-B, respectively) in Beijing region were investigated. The results showed that the pH values, nutrient contents, trace elements and heavy metals in CSS-A and CSS-B depended on the sludge resources and particular years. The average of organic matter content in different years (203 338.0 mg x kg(-1)) from CSS-A met both the requirement of sludge quality standard for agricultural use (CJ/T 309-2009) and land improvement (GB/T 24600-2009) in China except the permitted limit of sludge quality standards for garden or park use (GB/T 23486-2009) in China. Moreover, the average of organic matter in different years (298531.5 mg x kg(-1)) from CSS-B and the averages of pH values (7.1 and 7.2, respectively) and NPK concentrations (41 111.7 mg x kg(-1) and 65 901.5 mg x kg(-1), respectively) in different years from CSS-A and CSS-B all met the requirements of sludge quality standards for the above-mentioned disposal types of sewage sludge from municipal wastewater treatment plants. The contents of heavy metals in CSS-A and CSS-B except Hg and Ni were below the permitted limits of the A-class sludge quality standard for agricultural use (CJ/T 309-2009) , being the most stringent standards in China. It was suggested that composted sewage sludge from different municipal wastewater treatment plants in Beijing region use as a fertilizer in agriculture, land improvement, and garden or park, but the top concern about potential environmental pollution of Hg and Ni should be considered.

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

    PubMed

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

    2014-02-01

    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.

  10. Influence of ozone pre-treatment on sludge anaerobic digestion: removal of pharmaceutical and personal care products.

    PubMed

    Carballa, Marta; Manterola, Garbiñe; Larrea, Luis; Ternes, Thomas; Omil, Francisco; Lema, Juan M

    2007-04-01

    The effect of an oxidative pre-treatment with ozone on the removal of Pharmaceutical and Personal Care Products (PPCPs) during the anaerobic digestion of sewage sludge has been investigated. Besides, the digested sludge characteristics in terms of pathogens content, dewatering properties, heavy metals content and linear alkylbenzene sulfonates (LAS) were determined. During ozonation (20mg O(3)/g TSS), about 8% of volatile solids (VS) and 60% of the chemical oxygen demand (COD) were solubilized. However, no mineralization was observed. The elimination of VS and total COD during anaerobic digestion were not affected by ozone treatment with efficiencies ranging from 60% to 65%. All PPCPs considered were removed during anaerobic treatment of sludge, with efficiencies ranging from 20% to 99%. No significant influence of ozone pre-treatment was observed on PPCPs elimination except for carbamazepine. Pathogens, heavy metals and LAS contents after conventional and pre-ozonation treatment of sewage sludge were below the legal requirements. However, the dewatering properties of sludge were deteriorated when the ozone pre-treatment was applied.

  11. Behavior, fate, and mass loading of short chain chlorinated paraffins in an advanced municipal sewage treatment plant.

    PubMed

    Zeng, Lixi; Li, Huijuan; Wang, Thanh; Gao, Yan; Xiao, Ke; Du, Yuguo; Wang, Yawei; Jiang, Guibin

    2013-01-15

    Sewage treatment plants (STP) are an important source of short chain chlorinated paraffins (SCCPs) to the ambient environment through discharge of effluent and application of sludge. In this work, a field study was conducted to determine the behavior and possible removal of SCCPs during the sewage treatment process in an advanced municipal STP in Beijing, China. SCCPs were detected in all sewage water and sludge samples, and 97% of the initial mass loading in raw sewage was found to be associated with suspended matter. The total concentrations in raw influent, tertiary effluent, and dewatered sludge were 184 ± 19 ng/L, 27 ± 6 ng/L, and 15.6 ± 1.4 μg/g dry weight (d.w.), respectively. The dissolved concentrations of total SCCPs (∑SCCPs) significantly decreased during mechanical, biological, and chemical treatments. SCCP homologue profiles in aqueous phase were distinctly different from those in solid phase. Along the treatment process, the relative abundance of shorter chain and lower chlorinated congeners gradually increased in sewage water, but no obvious variations of homologue profiles were found in sludge. Mass flow analysis indicated, the removal efficiency in aqueous phase for ∑SCCPs was 82.2%, and the congener-specific removal efficiencies were positively related to their solid-water partition coefficients (K(d)). Mass balance results indicated that 0.8% and 72.6% of the initial SCCP mass loading were ultimately found in the effluents and dewatered sludge, respectively, while the remaining 26.6% was lost mainly due to biodegradation/biotransformation. It was suggested that the activated sludge system including basic anaerobic-anoxic-aerobic processes played an effective role in removing SCCPs from the wastewater, while the sorption to sludge by hydrophobic interactions was an important fate of SCCPs during the sewage treatment.

  12. Treatment of artificial soybean wastewater anaerobic effluent in a continuous aerobic-anaerobic coupled (CAAC) process with excess sludge reduction.

    PubMed

    Wang, Jun; Li, Xiaoxia; Fu, Weichao; Wu, Shihan; Li, Chun

    2012-12-01

    In this study, treatment of artificial soybean wastewater anaerobic effluent was studied in a continuous aerobic-anaerobic coupled (CAAC) process. The focus was on COD and nitrogen removal as well as excess sludge reduction. During the continuous operation without reflux, the COD removal efficiency was 96.5% at the optimal hydraulic retention time (HRT) 1.3 days. When HRT was shortened to 1.0 day, reflux from anaerobic zone to moving bed biofilm reactor (MBBR) was introduced. The removal efficiencies of COD and TN were 94.4% and 76.0% at the optimal reflux ratio 30%, respectively. The sludge yield coefficient of CAAC was 0.1738, the simultaneous removal of COD and nitrogen with in situ sludge reduction could be achieved in this CAAC process. The sludge reduction mechanism was discussed by soluble components variation along the water flow.

  13. Lime and fly ash stabilization of wastewater treatment sludge

    SciTech Connect

    Burns, H.; Gremminger, L.

    1994-01-11

    This invention provides a process meeting the EPA's PFRP standard for WWTS treatment thereby producing a readily usable end-product in either soil-like form or semi-impermeable low load bearing, mass form. The process includes mixing WWTS with lime and fly ash, to cause a temperature increase to above 70 C for at least 30 minutes and to cause the pH to exceed 12 for at least 2 hours. The end-product may be compacted to produce an semi-impermeable, durable mass or the soil-like product may be used as landfill cover material. 3 figs.

  14. Para-chlorophenol containing synthetic wastewater treatment in an activated sludge unit: effects of hydraulic residence time.

    PubMed

    Kargi, Fikret; Konya, Isil

    2007-07-01

    Due to the toxic nature of chlorophenol compounds present in some chemical industry effluents, biological treatment of such wastewaters is usually realized with low treatment efficiencies. Para-chlorophenol (4-chlorophenol, 4-CP) containing synthetic wastewater was treated in an activated sludge unit at different hydraulic residence times (HRT) varying between 5 and 30 h while the feed COD (2500 mg l(-1)), 4-CP (500 mg l(-1)) and sludge age (SRT, 10 days) were constant. Effects of HRT variations on COD, 4-CP, toxicity removals and on settling characteristics of the sludge were investigated. Percent COD removals increased and the effluent COD concentrations decreased when HRT increased from 5 to 15 h and remained almost constant for larger HRT levels. Nearly, 91% COD and 99% 4-CP removals were obtained at HRT levels above 15 h. Because of the highly concentrated microbial population at HRT levels of above 15 h, low effluent (reactor) 4-CP concentrations and almost complete toxicity removals were obtained. High biomass concentrations obtained at HRT levels above 15 h were due to low 4-CP contents in the aeration tank yielding negligible inhibition effects and low maintenance requirements. The sludge volume index (SVI) decreased with increasing HRT up to 15 h due to high biomass concentrations at high HRT levels resulting in well settling sludge with low SVI values. Hydraulic residence times above 15 h resulted in more than 90% COD and complete 4-CP and toxicity removals along with well settling sludge.

  15. Estrogenic compounds in Tunisian urban sewage treatment plant: occurrence, removal and ecotoxicological impact of sewage discharge and sludge disposal.

    PubMed

    Belhaj, Dalel; Athmouni, Khaled; Jerbi, Bouthaina; Kallel, Monem; Ayadi, Habib; Zhou, John L

    2016-12-01

    The occurrence, fate and ecotoxicological assessment of selected estrogenic compounds were investigated at Tunisian urban sewage treatment plant. The influents, effluents, as well as primary, secondary and dehydrated sludge, were sampled and analyzed for the target estrogens to evaluate their fate. All target compounds were detected in both sewage and sludge with mean concentrations from 0.062 to 0.993 μg L(-1) and from 11.8 to 792.9 μg kg(-1)dry weight, respectively. A wide range of removal efficiencies during the treatment processes were observed, from 6.3 % for estrone to 76.8 % for estriol. Ecotoxicological risk assessment revealed that the highest ecotoxicological risk in sewage effluent and dehydrated sludge was due to 17β-estradiol with a risk quotient (RQ) of 4.6 and 181.9, respectively, and 17α-ethinylestradiol with RQ of 9.8 and 14.85, respectively. Ecotoxicological risk after sewage discharge and sludge disposal was limited to the presence of 17β-estradiol in dehydrated-sludge amended soil with RQ of 1.38. Further control of estrogenic hormones in sewage effluent and sludge is essential before their discharge and application in order to prevent their introduction into the natural environment.

  16. Occurrence and distribution of organophosphate triesters and diesters in sludge from sewage treatment plants of Beijing, China.

    PubMed

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

    2016-02-15

    The occurrence and distribution of 14 organophosphate (OP) triesters and 5 diesters were investigated in sludge from eight sewage treatment plants (STPs) in Beijing, China, during 2008-2014. Tri(2-ethylhexyl) phosphate (TEHP) and tri-m-cresyl phosphate (TCrP) were the predominant triesters with the average concentration of 233-137 μg/kg, respectively. Also, the polar and hydrophilic trimethyl phosphate (TMP) and triethyl phosphate (TEP) were detected in 19% and 74% of sludge samples, respectively. Three of five diesters were detected in sludge samples, and di(2-ethylhexyl) phosphate (DEHP) revealed the highest average concentration of 96.0 μg/kg, followed by diphenyl phosphate (DPhP, 18.0 μg/kg). The levels of OP triesters in sludge varied with the compositions of the sewage and treatment capacity of STPs, as well as the adjacent sources. In comparison with that in the former years, relatively higher concentration of total OP triesters in sludge was observed in 2014, which is consistent with the rapid growth in consumption of these chemicals in China. Finally, environmental risk assessment indicated potential harmful effects of OP triesters on soil microorganisms after sludge landfill or fertilization.

  17. Degradation of aromatic amines in textile-dyeing sludge by combining the ultrasound technique with potassium permanganate treatment.

    PubMed

    Liang, Jieying; Ning, Xun-An; An, Taicheng; Sun, Jian; Zhang, Yaping; Wang, Yujie

    2016-08-15

    This paper reports, for the first time, a combined technique of ultrasound (US) with KMnO4 degradation of aromatic amines in a textile-dyeing sludge. The reaction mechanisms and the degradation kinetics of aromatic amines at various operating parameters (KMnO4 dosage, US power density and pH) were systematically examined by the combined system of US-KMnO4. The results indicated that there was a synergistic effect between US and KMnO4, as US greatly enhanced KMnO4 in the degradation of aromatic amines and exhibited apparent sludge disintegration and separated pollutants from the sludge. In addition to accelerating the Mn(VII) reaction with pollutants in the filtrate, US also caused Mn(VII) to enter the porous sludge and sufficiently facilitated the reaction of the strongly absorbed aromatic amines. The combined treatment of US-KMnO4 was effective in the degradation of aromatic amines in textile-dyeing sludge. On average, 58.7% of monocyclic anilines, 88.3% of other forms of aromatic amines, and 24.0% of TOC were removed under the optimal operating conditions of a KMnO4 dosage of 12mM, an US power density of 1.80W/cm(3) and pH 5. The present study proposed US-KMnO4 treatment as a practical method for the disposal of aromatic amines in textile-dyeing sludge.

  18. Improved azo dye decolorization in an advanced integrated system of bioelectrochemical module with surrounding electrode deployment and anaerobic sludge reactor.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-01-01

    A new integrated system, embedding a modular bioelectrochemical system (BES) with surrounding electrode deployment into an anaerobic sludge reactor (ASR), was developed to improve azo dye decolorization. Results demonstrated that the AO7 decolorization and COD removal can be improved without co-substrate in such system. The kinetic rate of decolorization (0.54h(-1)) in integrated system was 1.4-fold and 54.0-fold higher than that in biocathode BES (0.39h(-1)) and ASR (0.01h(-1)), respectively. COD can be removed after cleavage of azo bond, different from biocathode BES. The combined advantages of this integrated system were achieved by the cooperation of biocathode in modular BES and sludge in ASR. Biocathode was a predominant factor in AO7 decolorization, and anaerobic sludge contributed negligibly to AO7 reduction decolorization but mostly in the COD removal. These results demonstrated the great potential of integrating a BES module with anaerobic treatment process for azo dye treatment.

  19. Stabilization of tannery sludge by co-treatment with aluminum anodizing sludge and phytotoxicity of end-products.

    PubMed

    Pantazopoulou, E; Zebiliadou, O; Mitrakas, M; Zouboulis, A

    2017-03-01

    A global demand for efficient re-utilization of produced solid wastes, which is based on the principles of re-use and recycling, results to a circular economy, where one industry's waste becomes another's raw material and it can be used in a more efficient and sustainable way. In this study, the influence of a by-product addition, such as aluminum anodizing sludge, on tannery waste (air-dried sludge) stabilization was examined. The chemical characterization of tannery waste leachate, using the EN 12457-2 standard leaching test, reveals that tannery waste cannot be accepted even in landfills for hazardous wastes, according to the EU Decision 2003/33/EC. The stabilization of tannery waste was studied applying different ratios of tannery waste and aluminum anodizing sludge, i.e. 50:50, 60:40, 70:30 and 80:20 ratios respectively. Subsequently, the stabilization rate of the qualified as optimum homogenized mixture of 50:50 ratio was also tested during time (7, 15 and 30days). Moreover, this stabilized product was subjected to phytotoxicity tests using the Lepidium sativum, Sinapis alba and Sorghum saccharatum seeds. The experimental results showed that aluminum anodizing sludge managed to stabilize effectively chromium and organic content of tannery waste, which are the most problematic parameters influencing its subsequent disposal. As a result, tannery waste stabilized with the addition of aluminum anodizing sludge at 50:50 ratio can be accepted in non-hazardous waste landfills, as chromium and dissolved organic carbon concentrations in the respective leachate are below the relevant regulation limits, while the stabilized waste shows decreased phytotoxicity.

  20. NASA Bioreactors Advance Disease Treatments

    NASA Technical Reports Server (NTRS)

    2009-01-01

    the body. Experiments conducted by Johnson scientist Dr. Thomas Goodwin proved that the NASA bioreactor could successfully cultivate cells using simulated microgravity, resulting in three-dimensional tissues that more closely approximate those in the body. Further experiments conducted on space shuttle missions and by Wolf as an astronaut on the Mir space station demonstrated that the bioreactor s effects were even further expanded in space, resulting in remarkable levels of tissue formation. While the bioreactor may one day culture red blood cells for injured astronauts or single-celled organisms like algae as food or oxygen producers for a Mars colony, the technology s cell growth capability offers significant opportunities for terrestrial medical research right now. A small Texas company is taking advantage of the NASA technology to advance promising treatment applications for diseases both common and obscure.

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

    PubMed

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

    2014-07-01

    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 μg/capita/day, followed by sucralose (117 μg/capita/day), acesulfame (90 μg/capita/day), and saccharin (66μg/capita/day). The per-capita emission rates of select PPCPs, such as antimicrobials (triclocarban: 158 μg/capita/day) and analgesics (acetaminophen: 59 μg/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.

  2. Life cycle assessment of advanced bioethanol production from pulp and paper sludge.

    PubMed

    Sebastião, Diogo; Gonçalves, Margarida S; Marques, Susana; Fonseca, César; Gírio, Francisco; Oliveira, Ana C; Matos, Cristina T

    2016-05-01

    This work evaluates the environmental performance of using pulp and paper sludge as feedstock for the production of second generation ethanol. An ethanol plant for converting 5400 tons of dry sludge/year was modelled and evaluated using a cradle-to-gate life cycle assessment approach. The sludge is a burden for pulp and paper mills that is mainly disposed in landfilling. The studied system allows for the valorisation of the waste, which due to its high polysaccharide content is a valuable feedstock for bioethanol production. Eleven impact categories were analysed and the results showed that enzymatic hydrolysis and neutralisation of the CaCO3 are the environmental hotspots of the system contributing up to 85% to the overall impacts. Two optimisation scenarios were evaluated: (1) using a reduced HCl amount in the neutralisation stage and (2) co-fermentation of xylose and glucose, for maximal ethanol yield. Both scenarios displayed significant environmental impact improvements.

  3. Sludge treatment and reuse considering different climates and varying other conditions--export-oriented research for developing and threshold countries.

    PubMed

    Bauerfeld, Katrin; Dockhorn, Thomas; Dichtl, Norbert

    2008-11-01

    Sewage sludge accumulating during biological wastewater treatment has to be treated appropriately to avoid impacts on the environment and risks to public health. Especially pathogen reduction is necessary when sludge is disposed or reused in such a way that human contact is possible. In industrialized countries various sludge treatment technologies are available, but these are often only approved under local conditions. When exporting these technologies and experiences to other countries, a number of factors have to be taken into account including climatic, sociocultural, political and financial aspects. This paper gives an overview of current knowledge regarding sewage sludge treatment in developing countries. Various sanitation projects are realized worldwide and experiences from these plants already in operation are summarized. Results of on going laboratory experiments in climatic chambers regarding aerobic and anaerobic stabilization as well as lime treatment are shown to define the best-practicable sludge treatment technology for a certain climate. Options for final reuse or disposal are presented depending on end-product quality.

  4. A review of the technological solutions for the treatment of oily sludges from petroleum refineries.

    PubMed

    da Silva, Leonardo Jordão; Alves, Flávia Chaves; de França, Francisca Pessôa

    2012-10-01

    The activities of the oil industry have several impacts on the environment due to the large amounts of oily wastes that are generated. The oily sludges are a semi-solid material composed by a mixture of clay, silica and iron oxides contaminated with oil, produced water and the chemicals used in the production of oil. Nowadays both the treatment and management of these waste materials is essential to promote sustainable management of exploration and exploitation of natural resources. Biological, physical and chemical processes can be used to reduce environmental contamination by petroleum hydrocarbons to acceptable levels. The choice of treatment method depends on the physical and chemical properties of the waste as well as the availability of facilities to process these wastes. Literature provides some operations for treatment of oily sludges, such as landfilling, incineration, co-processing in clinkerization furnaces, microwave liquefaction, centrifugation, destructive distillation, thermal plasma, low-temperature conversion, incorporation in ceramic materials, development of impermeable materials, encapsulation and biodegradation in land farming, biopiles and bioreactors. The management of the technology to be applied for the treatment of oily wastes is essential to promote proper environmental management, and provide alternative methods to reduce, reuse and recycle the wastes.

  5. Understanding the distribution, degradation and fate of organophosphate esters in an advanced municipal sewage treatment plant based on mass flow and mass balance analysis.

    PubMed

    Liang, Kang; Liu, Jingfu

    2016-02-15

    Although organophosphate esters (OPEs) in the ambient environment are from sewage treatment plants due to the discharge of effluent and application of sludge, the distribution, degradation and fate of OPEs in advanced municipal sewage treatment plants remain unclear. This work focused on the use of mass flow and mass balance analysis to understand the behaviors and fate of 14 OPEs in an advanced municipal sewage treatment plant. OPEs were detected in all sewage water and sludge samples with total OPEs (ΣOPEs) concentrations of 1399 ± 263 ng/L in raw sewage aqueous phase, 833 ± 175 ng/L in tertiary effluent aqueous phase, and 315 ± 89 ng/g dry weight in dewatered sludge. The dissolved concentrations of ΣOPEs significantly decreased during biological treatment, whereas negligible decrease was observed in mechanical and physical-chemical treatments. For individual OPE, the chlorinated tris(2-chloroethyl) phosphate (TCEP) and tris(2-chloroisopropyl) phosphate (TCPP) did not decrease but increased during both biological treatment and physical-chemical treatment. Mass flow analysis indicated the total removal efficiency of ΣOPEs in aqueous phase was 40.5%, and the polarity-specific removal efficiencies for individual OPE were positively related to their solid-water partition coefficients (Kd). Furthermore, mass balance results showed that 53.1% and 6.3% of the initial OPE mass flow were eventually transferred to the effluents and dewatered sludge, respectively, while the remaining 39.9% and 0.7% were lost due to biodegradation and physical-chemical treatment, respectively. It was indicated that the activated sludge treatment system with anaerobic/anoxic/aerobic bioreactors was a major factor in the removal of OPEs from the raw sewage, while transfer to dewatered sludge governed by hydrophobic interactions was limited during the sewage treatment. Meanwhile, the degradation difference of OPEs in activated sludge treatment was more related with their molecular

  6. Electrokinetic treatment of contaminated soils, sludges, and lagoons. Final report

    SciTech Connect

    Wittle, J.K.; Pamukcu, S.

    1993-04-01

    The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium.

  7. Treatment of phenol and cresols in upflow anaerobic sludge blanket (UASB) process: a review.

    PubMed

    Veeresh, Gali S; Kumar, Pradeep; Mehrotra, Indu

    2005-01-01

    Upflow anaerobic sludge blanket (UASB) process has been successfully applied in the treatment of municipal and industrial wastewaters. Several researchers have investigated the suitability of the process for the treatment of phenols and phenolic wastewaters. The anaerobic treatment of phenols is still at an investigative stage. With increasing recognition of the UASB process, feasibility studies on the treatment of wastewater containing phenol and cresols (o-, m- and p- isomers) in UASB have been reviewed. It is reported that phenol concentration up to a range of 500-750 mg/L is generally not inhibitory to the UASB process. Phenol concentrations greater than 500 mg/L can be effectively treated with acclimatization of inocula, recirculation of the treated effluent and/or supplementing with co-substrates such as glucose, VFA and dilute molasses. The degradability of phenol is more than p-cresol, which in turn is more than m- and o-cresol.

  8. Feasibility study of the applicability of the activated sludge process to treatment of radioactive organic liquid waste

    SciTech Connect

    Koyama, Akio; Nishimaki, Kenzo

    1997-12-31

    The authors used an activated sludge process to treat radioactive organic liquid waste. Organic liquid waste is difficult to treat by conventional radioactive liquid treatment processes, but in order to reduce long-term irradiation of the public the removal of radionuclides from such waste is preferable to dilution. Activated sludge processes are widely used for the biological treatment of sewage and are considered appropriate means for treating radioactive organic liquid waste. In this process, the fate of radionuclides eluted by treated water or immobilized by activated sludge, is extremely important for public safety and for the treatment of radioactive organic liquid waste. The authors performed uptake and desorption behavior experiments on the three short half-life radionuclides {sup 134}Cs, {sup 57}Co and {sup 85}Sr, and used three nutritive types of artificial sewage as the feed solution. On the basis of the results, they discuss the uptake-desorption behavior of these radionuclides in an activated sludge process. The authors conclude that treatment of radioactive organic liquid waste by an activated sludge process is possible, but improvements must be made in the process if it is to be more effective.

  9. Thermochemical treatment of sewage sludge ash with sodium salt additives for phosphorus fertilizer production--Analysis of underlying chemical reactions.

    PubMed

    Stemann, Jan; Peplinski, Burkhard; Adam, Christian

    2015-11-01

    Stocks of high grade phosphate rock are becoming scarce, and there is growing concern about potentially harmful impurities in conventional phosphorus fertilizers. Sewage sludge ash is a promising secondary phosphorus source. However, to remove heavy metals and convert the phosphorus contained in sewage sludge ash into mineral phases available to plants, an after-treatment is required. Laboratory-scale calcination experiments of sewage sludge ash blended with sodium salts using dried sewage sludge as a reducing agent were carried out at 1000°C. Thus, the Ca3(PO4)2 or whitlockite component of raw sewage sludge ash, which is not readily plant available, was converted to CaNaPO4 (buchwaldite). Consequently, nearly complete phosphorus solubility in ammonium citrate (a well-established indicator for plant availability) was achieved. Moreover, it was shown that Na2CO3 may be replaced by moderately priced Na2SO4. However, molar ratios of Na/P>2 were required to achieve >80% phosphorus solubility. Such over-stoichiometric Na consumption is largely caused by side reactions with the SiO2 component of the sewage sludge ash - an explanation for which clear evidence is provided for the first time.

  10. Improving thermal dewatering characteristics of mechanically dewatered sludge: response surface analysis of combined lime-heat treatment.

    PubMed

    Tunçal, Tolga

    2011-05-01

    In this study, disintegration of dewatered sludge (dry solids content [DS%] = 23 +/- 2) was studied to assess the possibility of enhancing the overall performance of a thermal dewatering processes. Powdered lime was used as an alkaline disintegrator. The combined effects of drying temperature, powdered lime dosage, and organic content on the thermal drying rate of dewatered sludge were investigated in a full-scale wastewater treatment plant. Effects of selected design parameters on the sludge drying rate were modeled using a response surface method. In addition, the possible interaction between lost on ignition and total organic carbon parameters also was investigated statistically. Specific resistance to filtration and free water contents of raw and disintegrated mixed sludge (DS% = 1.0 to 1.8) samples were compared statistically. The obtained results indicated that all of the selected design parameters have a significant effect on thermal dewatering characteristics, and the alkaline disintegration technique could remarkably improve thermal evaporation rate of dewatered sludge. These results are important because they could help to establish a sustainable sludge management model, which is critical in reducing environmental health risks.

  11. Anaerobic treatment of activated sludge from Swedish pulp and paper mills--biogas production potential and limitations.

    PubMed

    Karlsson, Anna; Truong, Xu-Bin; Gustavsson, Jenny; Svensson, Bo H; Nilsson, Fredrik; Ejlertsson, Jörgen

    2011-10-01

    The methane potential of activated sludge from six Swedish pulp and paper mills was evaluated. The methane production potential of sludge samples ranged from 100-200 NmL CH4 g(-1) volatile solids (VS) and for four of the six sludge samples the potential exceeded 170 NmL CH4 g(-1) VS. The effects of sludge age and dewatering on the methane production potential were evaluated. The effects of enzymatic and ultrasonic pre-treatment on the digestibility of sludge were also investigated, but energy or enzyme inputs in viable ranges did not exert a detectable, positive effect. Long-term, semi-continuous trials with sludge from two of the mills were also conducted in attempts to develop stable biogas production at loading rates up to 4 g VS L(-1). Cobalt addition (0.5 mg L(-1)) was here found to positively affect the turnover of acetate. High viscosity was a problem in all the experimental reactors and this limited the organic loading rate.

  12. Vermicomposting of sludge from animal wastewater treatment plant mixed with cow dung or swine manure using Eisenia fetida.

    PubMed

    Xie, Dan; Wu, Weibing; Hao, Xiaoxia; Jiang, Dongmei; Li, Xuewei; Bai, Lin

    2016-04-01

    Vermicomposting of animal wastewater treatment plant sludge (S) mixed with cow dung (CD) or swine manure (SM) employing Eisenia fetida was tested. The numbers, weights, clitellum development, and cocoon production were monitored for 60 days at a detecting interval of 15 days. The results indicated that 100 % of the sludge can be the suitable food for growth and fecundity of E. fetida, while addition of CD or SM in sludge significantly (P < 0.05) increased the worm biomass and reproduction. The sludge amended with 40 % SM can be a great medium for the growth of E. fetida, and the sludge amended with 40 % CD can be a suitable medium for the fecundity of E. fetida. The addition of CD in sludge provided a better environment for the fecundity of earthworm than SM did. Moreover, vermicomposts obtained in the study had lower pH value, lower total organic carbon (TOC), lower NH4 (+)-N, lower C/N ratio, higher total available phosphorous (TAP) contents, optimal stability, and maturity. NH4 (+)-N, pH and TAP of the initial mixtures explained high earthworm growth. The results provided the theory basic both for management of animal wastes and the production of earthworm proteins using E. fetida.

  13. Heavy metal concentration and speciation of seven representative municipal sludges from wastewater treatment plants in Northeast China.

    PubMed

    Tu, Jiangcheng; Zhao, Qingliang; Wei, Liangliang; Yang, Qianqian

    2012-03-01

    The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni) in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China, for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis (PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability, while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals.

  14. Peracetic acid oxidation as an alternative pre-treatment for the anaerobic digestion of waste activated sludge.

    PubMed

    Appels, Lise; Van Assche, Ado; Willems, Kris; Degrève, Jan; Van Impe, Jan; Dewil, Raf

    2011-03-01

    Anaerobic digestion is generally considered to be an economic and environmentally friendly technology for treating waste activated sludge, but has some limitations, such as the time it takes for the sludge to be digested and also the ineffectiveness of degrading the solids. Various pre-treatment technologies have been suggested to overcome these limitations and to improve the biogas production rate by enhancing the hydrolysis of organic matter. This paper studies the use of peracetic acid for disintegrating sludge as a pre-treatment of anaerobic digestion. It has been proved that this treatment effectively leads to a solubilisation of organic material. A maximum increase in biogas production by 21% is achieved. High dosages of PAA lead to a decrease in biogas production. This is due to the inhibition of the anaerobic micro-organisms by the high VFA-concentrations. The evolution of the various VFAs during digestion is studied and the observed trends support this hypothesis.

  15. Performance of an SBR-plant for advanced nutrient removal, using septic sludge as a carbon source.

    PubMed

    Morling, S

    2001-01-01

    The Tjustvik SBR-plant outside Stockholm, Sweden has been in operation for four years. The plant has to meet stringent effluent standards, BOD7 < 10 PPM, total N < 15 PPM and total P < 0.3 PPM. The plant is a typical two reactor SBR-plant, sized for about 15,000 inhabitants. During the first year of operation there were difficulties in meeting the P consent level. The difficulties were linked to a deficit of available organic carbon and a secondary phosphorus release. The problem was solved with the addition of septic sludge, in an amount equivalent to about 10,000 to 15,000 inhabitants with respect to the BOD-load. The altered operation resulted in a very stable and good effluent quality from the plant that has been maintained ever since, giving typical discharge levels as follows: BOD7, < 3 mg/l; Total-P, < 0.15 mg/l; Total-N, < 7 mg/l; NH4-N, < 1 mg/l. The change of process saved the community from a major investment in a separate treatment facility for the septic sludge. The stabilisation degree of the waste activated sludge is sufficient to by pass the anaerobic digestion for the time being. In the beginning, the SBR-process stability played an unwanted role during start up as it maintained a secondary phosphorus release for a considerable time. Later the process stability became an asset as the varying loads from the septic sludge addition were handled with very good results.

  16. Evaluation of Municipal Wastewater Treatment Plant Activated Sludge for Biodegradation of Propylene Glycol as an Aircraft Deicing Fluid

    DTIC Science & Technology

    2012-03-01

    unit for use. 31 Explore other treatment and disposal options for used ADF. While anaerobic digestion of used ADF has been widely...scale sequencing batch reactor containing municipal waste water treatment facility activated sludge (AS) performing simultaneous organic carbon...all used ADF in an approved manner. Available options include recycling, disposal under a waste contract, or onsite pretreatment (United States EPA

  17. Treatment of high-strength synthetic sewage in a laboratory-scale upflow anaerobic sludge bed (UASB) with aerobic activated sludge (AS) post-treatment.

    PubMed

    Banihani, Qais H; Field, Jim A

    2013-01-01

    Performance of a combined system up-flow anaerobic sludge blanket (UASB) followed by aerobic treatment activated sludge (AS) for removal of carbonaceous and nitrogenous contaminants at an average temperature of 25°C was investigated. The combined system was fed with high strength synthetic sewage having chemical oxygen demand (COD) of 2500 mg L(-1). The organic loading rate (OLR) of the UASB reactor was increased gradually from 1.1 to 3.8 gCOD L(r) (-1) d(-1). At steady state condition, the UASB reactor achieved removal efficiency up to 83.5% of total COD (COD(tot)), 74.0% of volatile fatty acid (VFA) and 94.0% of protein. The combined system performed an excellent organic removal pushing the overall removal efficiency of COD(tot), VFA and protein to 91.0%, 99.9% and 98.2%, respectively. When the OLR of the UASB increased to 4.4 g COD L(r) (-1) d(-1), the UASB was overloaded and; thus, its effluent quality deteriorated. In respect to nitrogen removal, both partial nitrification and complete nitrification took place in aerobic post-treatment. When the dissolved oxygen (DO) concentration was >2.0 mg L(-1), complete nitrification (period B) occurred with an average nitrification efficiency of 96.2%. The partial nitrification occurred due to high OLR to AS during the overloading event (period A) and when DO concentration was <2.0 mg L(-1) (period C). The maximum accumulated nitrite concentration in periods A, B and C were 90.0, 0.9 and 75.8 mg NO(-) (2) -N L(-1), respectively. The nitrogen balance results of periods A and C indicated that there was a discrepancy between the amount of ammonium nitrogen removed and the amount of oxidized nitrogen formed. This suggests the occurrence of simultaneous nitrification/denitrification (SND) in aerobic post-treatment.

  18. Application of the upflow anaerobic sludge bed (UASB) process for treatment of complex wastewaters at low temperatures

    SciTech Connect

    Koster, I.W.; Lettinga, G.

    1985-10-01

    The feasibility of the upflow anaerobic sludge bed (UASB) process for the treatment of potato starch wastewater at low ambient temperatures was demonstrated by operating two 5.65 l reactors at 14 degrees C and 20 degrees C, respectively. The organic space loading rates achieved in these laboratory-scale reactors were 3 kg COD/cubic m/day at 14 degrees C and 4-5 kg COD/cubic m/day at 20 degrees C. The corresponding sludge loading rates were 0.12 kg COD/kg VSS/day at 14 degrees C and 0.16-0.18 kg COD/kg VSS/day at 20 degrees C. These findings are of considerable practical importance because application of anaerobic treatment at low ambient temperatures will lead to considerable savings in energy needed for operating the process. As compared with various other anaerobic wastewater treatment processes, a granular sludge upflow process represents one of the best options developed so far. Although the overall sludge yield under psychrophilic conditions is slightly higher than under optimal mesophilic conditions, this doesn't seriously hamper the operation of the process. The extra sludge yield, due to accumulation of slowly hydrolyzing substrate ingredients, was 4.75% of the COD input at 14 degrees C and 1.22% of the COD input at 20 degrees C. 26 references.

  19. A novel conversion of the groundwater treatment sludge to magnetic particles for the adsorption of methylene blue.

    PubMed

    Zhu, Suiyi; Fang, Shuai; Huo, Mingxin; Yu, Yang; Chen, Yu; Yang, Xia; Geng, Zhi; Wang, Yi; Bian, Dejun; Huo, Hongliang

    2015-07-15

    Iron sludge, produced from filtration and backwash of groundwater treatment plant, has long been considered as a waste for landfill. In this study, iron sludge was reused to synthesize Fe3O4 magnetic particles (MPs) by using a novel solvothermal process. Iron sludge contained abundant amounts of silicon, iron, and aluminum and did not exhibit magnetic properties. After treatment for 4h, the amorphous Fe in iron sludge was transformed into magnetite Fe3O4, which could be easily separated from aqueous solution with a magnet. The prepared particles demonstrated the intrinsic properties of soft magnetic materials and could aggregate into a size of 1 μm. MPs treated for 10h exhibited excellent magnetic properties and a saturation magnetization value of 9 emu/g. The obtained particles presented the optimal adsorption of methylene blue under mild conditions, and the maximum adsorption capacity was 99.4 mg/g, which was higher than that of granular active carbon. The simple solvothermal method can be used to prepare Fe3O4 MPs from iron sludge, and the products could be applied to treatment of dyeing wastewater.

  20. Effect of free nitrous acid pre-treatment on primary sludge at low exposure times.

    PubMed

    Zahedi, S; Icaran, P; Yuan, Z; Pijuan, M

    2017-03-01

    The present study was undertaken to investigate the effect of different free nitrous acid (FNA) concentrations at low pre-treatment times (PTs) (1, 2 and 5h) and without pH control with mild agitation on primary sludge (PS) biodegradability and methane production (MP). Increasing PTs resulted in an increase in the solubility of the organic matter (around 25%), but not on cell-mortality (>75% in all the cases with FNA) and neither on methane generation. FNA pre-treatment at low PTs improve MP (around 16% at PT of 1h and 650mg N-NO2(-)/L). However, a similar improvement was found with mild agitation of PS without FNA at 2 and 5h. Taking into account the potential costs associated with the FNA pre-treatment, a mild agitation without FNA would be preferred to enhance MP in PS.

  1. 6:2 fluorotelomer sulfonate aerobic biotransformation in activated sludge of waste water treatment plants.

    PubMed

    Wang, Ning; Liu, Jinxia; Buck, Robert C; Korzeniowski, Stephen H; Wolstenholme, Barry W; Folsom, Patrick W; Sulecki, Lisa M

    2011-02-01

    The aerobic biotransformation of 6:2 FTS salt [F(CF2)6CH2CH2SO3- K+] was determined in closed bottles for 90d in diluted activated sludge from three waste water treatment plants (WWTPs) to compare its biotransformation potential with that of 6:2 FTOH [F(CF2)6CH2CH2OH]. The 6:2 FTS biotransformation was relatively slow, with 63.7% remaining at day 90 and all observed transformation products together accounting for 6.3% of the initial 6:2 FTS applied. The overall mass balance (6:2 FTS plus observed transformation products) at day 90 in live and sterile treatments averaged 70% and 94%, respectively. At day 90, the stable transformation products observed were 5:3 acid [F(CF2)5CH2CH2COOH, 0.12%], PFBA [F(CF2)3COOH, 0.14%], PFPeA [F(CF2)4COOH, 1.5%], and PFHxA [F(CF2)5COOH 1.1%]. In addition, 5:2 ketone [F(CF2)5C(O)CH3] and 5:2 sFTOH [F(CF2)5CH(OH)CH3] together accounted for 3.4% at day 90. The yield of all the stable transformation products noted above (2.9%) was 19 times lower than that of 6:2 FTOH in aerobic soil. Thus 6:2 FTS is not likely to be a major source of PFCAs and polyfluorinated acids in WWTPs. 6:2 FTOH, 6:2 FTA [F(CF2)6CH2COOH], and PFHpA [F(CF2)6COOH] were not observed during the 90-d incubation. 6:2 FTS primary biotransformation bypassed 6:2 FTOH to form 6:2 FTUA [F(CF2)5CF=CHCOOH], which was subsequently degraded via pathways similar to 6:2 FTOH biotransformation. A substantial fraction of initially dosed 6:2 FTS (24%) may be irreversibly bound to diluted activated sludge catalyzed by microbial enzymes. The relatively slow 6:2 FTS degradation in activated sludge may be due to microbial aerobic de-sulfonation of 6:2 FTS, required for 6:2 FTS further biotransformation, being a rate-limiting step in microorganisms of activated sludge in WWTPs.

  2. Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge.

    PubMed

    Tian, Xinbo; Trzcinski, Antoine Prandota; Lin, Li Leonard; Ng, Wun Jern

    2015-07-01

    Impact of ultrasonication (ULS) and ultrasonication-ozonation (ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time (SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 mL biogas/g CODfed and the volatile solid (VS) removals were 35.6%, 38.3% and 42.1%, respectively at SRT of 10 days. At SRT of 20 days, the biogas yields reached 313, 337 and 393 mL biogas/g CODfed and the VS removal rates were 37.3%, 40.9% and 45.3% in the control, ULS and ULS-Ozone reactors, respectively. ULS-Ozone pre-treatment increased the residual organic amount in the digested sludge. These soluble residual organics were found to contain macromolecules with molecular weights (MW) larger than 500 kDa and smaller polymeric products with MW around 19.4 and 7.7 kDa. These compounds were further characterized to be humic acid-like substances with fluorescent spectroscopy analysis.

  3. Simulation and optimization of a coking wastewater biological treatment process by activated sludge models (ASM).

    PubMed

    Wu, Xiaohui; Yang, Yang; Wu, Gaoming; Mao, Juan; Zhou, Tao

    2016-01-01

    Applications of activated sludge models (ASM) in simulating industrial biological wastewater treatment plants (WWTPs) are still difficult due to refractory and complex components in influents as well as diversity in activated sludges. In this study, an ASM3 modeling study was conducted to simulate and optimize a practical coking wastewater treatment plant (CWTP). First, respirometric characterizations of the coking wastewater and CWTP biomasses were conducted to determine the specific kinetic and stoichiometric model parameters for the consecutive aeration-anoxic-aeration (O-A/O) biological process. All ASM3 parameters have been further estimated and calibrated, through cross validation by the model dynamic simulation procedure. Consequently, an ASM3 model was successfully established to accurately simulate the CWTP performances in removing COD and NH4-N. An optimized CWTP operation condition could be proposed reducing the operation cost from 6.2 to 5.5 €/m(3) wastewater. This study is expected to provide a useful reference for mathematic simulations of practical industrial WWTPs.

  4. Removal of fluoride in aqueous solution by adsorption on acid activated water treatment sludge

    NASA Astrophysics Data System (ADS)

    Vinitnantharat, Soydoa; Kositchaiyong, Sriwilai; Chiarakorn, Siriluk

    2010-06-01

    This paper reports the use of a pellet of adsorbent made from water treatment sludge (S) and acid activated water treatment sludge (SH) for removal of fluoride in the batch equilibration technique. The influence of pH, adsorbent dosage, temperature and effect of other ions were employed to find out the feasibility of acid activated adsorbent to remove fluoride to the permissible concentration of 0.7 mg/L. The results from the adsorption isotherm followed both Langmuir and Freundlich models and the highest fluoride removal was found for adsorbent activated with acetic acid at 2.0 mol/L. The optimum adsorbent dosage was found at 40 g/L, 0.01 mol/L acid activated adsorbent which was able to adsorb fluoride from 10 down to 0.11 mg/L. The adsorption capacity was decreased when the temperature increased. This revealed that the adsorption of fluoride on SH was exothermic. In the presence of nitrate and carbonate ions in the aqueous solution, fluoride removal efficiency of SH decreased from 94.4% to 86.6% and 90.8%, respectively. However, there is no significant effect in the presence of sulfate and chloride ions.

  5. Preparation of sludge-based activated carbon and its application in dye wastewater treatment.

    PubMed

    Wang, Xiaoning; Zhu, Nanwen; Yin, Bingkui

    2008-05-01

    A novel activation process was adopted to produce highly porous activated carbon from cyclic activated sludge in secondary precipitator in municipal wastewater treatment plant for dye removal from colored wastewater. The physical properties of activated carbon produced with the activation of 3M KOH solution in the atmosphere of steam were investigated. Adsorption removal of a dye, Acid Brilliant Scarlet GR, from aqueous solution onto the sludge-based activated carbon was studied under varying conditions of adsorption time, initial concentration, carbon dosage and pH. Adsorption equilibrium was obtained in 15 min for the dye initial concentration of 300 mg/L. Initial pH of solution had an insignificant impact on the dye removal. Results indicated that 99.7% coloration and 99.6% total organic carbon (TOC) were removed after 15 min adsorption in the synthetic solution of Acid Brilliant Scarlet GR with initial concentration of 300 mg/L of the dye and 20 g/L activated carbon. The Langmuir and Freundlich equilibrium isotherm models fitted the adsorption data well with R(2)=0.996 and 0.912, respectively. Accordingly, it is concluded that the procedure of developing activated carbon used in this study could be effective and practical for utilizing in dye wastewater treatment.

  6. Sorption of ionized and neutral emerging trace organic compounds onto activated sludge from different wastewater treatment configurations.

    PubMed

    Hyland, Katherine C; Dickenson, Eric R V; Drewes, Jörg E; Higgins, Christopher P

    2012-04-15

    The objective of this study was to examine sorption of a suite of 19 trace organic contaminants (TOrCs) to activated sludge. Compounds examined in this study included neutral, nonionized TOrCs as well as acidic TOrCs which may carry a negative charge and basic TOrCs which may carry a positive charge at the pH of wastewater. These TOrCs were evaluated to examine how sorptive behavior might differ for TOrCs in different states of charge. Additionally, multiple sludges from geographically and operationally different wastewater treatment plants were studied to elicit how solid-phase characteristics influence TOrC sorption. Characterization of sludge solids from 6 full scale treatment facilities and 3 bench-scale reactors showed no significant difference in fraction organic carbon (f(oc)) and cation exchange capacity (CEC). Sorption experiments demonstrated that sorption of TOrCs also exhibits little variation between these different sludges. Organic carbon normalized partition coefficients (logK(oc)) were determined as a measure of sorption, and were found to correlate well with octanol-water partition coefficients (logK(ow)) for nonionized TOrCs, and logD(ow) for anionic TOrCs where logD(ow) is greater than 2. These data were used to construct a linear free energy relationship (LFER), which was comparable to existing LFERs for sorption onto sludge. No trend in sorption was apparent for the remaining anionic TOrCs or for the cationic TOrCs. These data suggest that predicting sorption to activated sludge based on K(ow) values is a reasonable approach for neutral TOrCs using existing LFERs, but electrostatic (and likely other) interactions may govern the sorptive behavior of the charged organic chemicals to sludge.

  7. Treatment of municipal landfill leachate using a combined anaerobic digester and activated sludge system

    SciTech Connect

    Kheradmand, S.; Karimi-Jashni, A.; Sartaj, M.

    2010-06-15

    The main objective of this study was to assess the feasibility of treating sanitary landfill leachate using a combined anaerobic and activated sludge system. A high-strength leachate from Shiraz municipal landfill site was treated using this system. A two-stage laboratory-scale anaerobic digester under mesophilic conditions and an activated sludge unit were used. Landfill leachate composition and characteristics varied considerably during 8 months experiment (COD concentrations of 48,552-62,150 mg/L). It was found that the system could reduce the COD of the leachate by 94% at a loading rate of 2.25 g COD/L/d and 93% at loading rate of 3.37 g COD/L/d. The anaerobic digester treatment was quite effective in removing Fe, Cu, Mn, and Ni. However, in the case of Zn, removal efficiency was about 50%. For the rest of the HMs the removal efficiencies were in the range 88.8-99.9%. Ammonia reduction did not occur in anaerobic digesters. Anaerobic reactors increased alkalinity about 3.2-4.8% in the 1st digester and 1.8-7.9% in the 2nd digester. In activated sludge unit, alkalinity and ammonia removal efficiency were 49-60% and 48.6-64.7%, respectively. Methane production rate was in the range of 0.02-0.04, 0.04-0.07, and 0.02-0.04 L/g COD{sub rem} for the 1st digester, the 2nd digester, and combination of both digesters, respectively; the methane content of the biogas varied between 60% and 63%.

  8. Effect of ultrasound pre-treatment in the anaerobic co-digestion of cattle manure with food waste and sludge.

    PubMed

    Quiroga, G; Castrillón, L; Fernández-Nava, Y; Marañón, E; Negral, L; Rodríguez-Iglesias, J; Ormaechea, P

    2014-02-01

    This paper presents a study of the effect of applying ultrasound pre-treatment in the production of methane when co-digesting mixtures of cattle manure with food waste and sludge. A series of experiments were carried out under mesophilic and thermophilic conditions in continuously stirred-tank reactors containing 70% cattle manure, 20% food waste and 10% sewage sludge. Ultrasound pre-treatment allows operating at lower HRT, achieving higher volumetric methane yields: 0.85 L CH4/L day at 36°C and 0.82 CH4/L day at 55°C, when cattle manure and sewage sludge were sonicated. With respect to the non-sonicated waste, these values represent increases of up to 31% and 67% for mesophilic and thermophilic digestion, respectively.

  9. Recent advances in leishmaniasis treatment.

    PubMed

    Tiuman, Tatiana S; Santos, Adriana O; Ueda-Nakamura, Tânia; Filho, Benedito P Dias; Nakamura, Celso V

    2011-08-01

    About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.

  10. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of heterogeneous catalytic ozonation and biological process.

    PubMed

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

    2014-08-01

    Advanced treatment of biologically pretreated coal gasification wastewater (CGW) was investigated employing heterogeneous catalytic ozonation integrated with anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) process. The results indicated that catalytic ozonation with the prepared catalyst (i.e. MnOx/SBAC, sewage sludge was converted into sludge based activated carbon (SBAC) which loaded manganese oxides) significantly enhanced performance of pollutants removal by generated hydroxyl radicals. The effluent of catalytic ozonation process was more biodegradable and less toxic than that in ozonation alone. Meanwhile, ANMBBR-BAF showed efficient capacity of pollutants removal in treatment of the effluent of catalytic ozonation at a shorter reaction time, allowing the discharge limits to be met. Therefore, the integrated process with efficient, economical and sustainable advantages was suitable for advanced treatment of real biologically pretreated CGW.

  11. Enhanced nitrogen removal in a wastewater treatment process characterized by carbon source manipulation with biological adsorption and sludge hydrolysis.

    PubMed

    Liu, Hongbo; Zhao, Fang; Mao, Boyang; Wen, Xianghua

    2012-06-01

    An innovative adsorption/nitrification/denitrification/sludge-hydrolysis wastewater treatment process (ENRS) characterized by carbon source manipulation with a biological adsorption unit and a sludge hydrolysis unit was developed to enhance nitrogen removal and reduce sludge production for municipal wastewater treatment. The system presented good performance in pollutants removal, yielding the effluent with average COD, NH(4)(+)-N, TN and TP of 48.5, 0.6, 13.2 and 1.0 mg/L, respectively. Sixty percent of the total carbon source in the influent was concentrated and separated by the quick adsorption of activated sludge, providing the possibilities of reusing waste carbon source in the denitrification tank and accumulating nitrobacteria in the nitrification tank. Low temperature of 6-15 °C and high hydraulic loading rate of 3.0-15.0 m(3)/d did not affect NH(4)(+)-N removal performance, yielding the NH(4)(+)-N of lower 1.0 mg/L in the effluent. Furthermore, 50% of the residual sludge in the ENRS system could be transformed into soluble COD (SCOD) by alkaline thermal hydrolysis with temperature of 60 °C and pH of 11, and the hydrolyzed carbon could completely substitute methanol as a good quality carbon to support high efficient denitrification.

  12. Activated Sludge.

    ERIC Educational Resources Information Center

    Saunders, F. Michael

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers: (1) activated sludge process; (2) process control; (3) oxygen uptake and transfer; (4) phosphorus removal; (5) nitrification; (6) industrial wastewater; and (7) aerobic digestion. A list of 136 references is also presented. (HM)

  13. Investigation into the use of cement kiln dust in high density sludge (HDS) treatment of acid mine water.

    PubMed

    Mackie, Allison L; Walsh, Margaret E

    2015-11-15

    The purpose of this study was to investigate the potential to replace lime with cement kiln dust (CKD) in high density sludge (HDS) treatment of acid mine drainage (AMD). The bench-scale study used two water samples: AMD sampled from a lead-zinc mine with high concentrations of iron (Fe), zinc (Zn), and arsenic (As) (Fe/Zn-AMD) and a synthetic AMD solution (Syn-AMD) spiked with ferric sulfate (Fe2(SO4)3). Arsenic was found to be significantly reduced with CKD-HDS treatment of Fe/Zn-AMD compared to lime-HDS treatment, to concentrations below the stringent mine effluent discharge regulation of 0.10 mg As/L (i.e., 0.04 ± 0.02 mg/L). Both CKD- and lime-HDS treatment of the two AMD samples resulted in settled water Fe concentrations above the stringent discharge guideline of 0.3 mg Fe/L. CKD addition in the HDS process also resulted in high settled water turbidity, above typical discharge guidelines of 15 mg TSS/L. CKD-HDS treatment was found to result in significantly improved settled solids (i.e., sludge) quality compared to that generated in the lime-HDS process. HDS treatment with CKD resulted in 25-88% lower sludge volume indices, 2 to 9 times higher % wet solids, and 10 to 20 times higher % dry solids compared to lime addition. XRD and XPS testing indicated that CKD-HDS sludge consisted of mainly CaCO3 and SiO2 with Fe(3+) precipitates attached at particle surfaces. XRD and XPS testing of the lime-HDS generated sludge showed that it consisted of non-crystalline Fe oxides typical of sludge formed from precipitates with a high water concentration. Increased sedimentation rates were also found for CKD (1.3 cm/s) compared to lime (0.3 cm/s). The increased solids loading with CKD addition compared to lime addition in the HDS process was suggested to both promote surface complexation of metal precipitates with insoluble CKD particles and increase compression effects during Type IV sedimentation. These mechanisms collectively contributed to the reduced water content of

  14. Aerobic granular sludge inoculated microbial fuel cells for enhanced epoxy reactive diluent wastewater treatment.

    PubMed

    Cheng, Kai; Hu, Jingping; Hou, Huijie; Liu, Bingchuan; Chen, Qin; Pan, Keliang; Pu, Wenhong; Yang, Jiakuan; Wu, Xu; Yang, Changzhu

    2017-04-01

    Microbial consortiums aggregated on the anode surface of microbial fuel cells (MFCs) are critical factors for electricity generation as well as biodegradation efficiencies of organic compounds. Here in this study, aerobic granular sludge (AGS) was assembled on the surface of the MFC anode to form an AGS-MFC system with superior performance on epoxy reactive diluent (ERD) wastewater treatment. AGS-MFCs successfully shortened the startup time from 13d to 7d compared to the ones inoculated with domestic wastewater. Enhanced toxicity tolerance as well as higher COD removal (77.8% vs. 63.6%) were achieved. The higher ERD wastewater treatment efficiency of AGS-MFC is possibly attributed to the diverse microbial population on MFC biofilm, as well as the synergic degradation of contaminants by both the MFC anode biofilm and AGS granules.

  15. Integral approaches to wastewater treatment plant upgrading for odor prevention: Activated Sludge and Oxidized Ammonium Recycling.

    PubMed

    Estrada, José M; Kraakman, N J R; Lebrero, R; Muñoz, R

    2015-11-01

    Traditional physical/chemical end-of-the-pipe technologies for odor abatement are relatively expensive and present high environmental impacts. On the other hand, biotechnologies have recently emerged as cost-effective and environmentally friendly alternatives but are still limited by their investment costs and land requirements. A more desirable approach to odor control is the prevention of odorant formation before being released to the atmosphere, but limited information is available beyond good design and operational practices of the wastewater treatment process. The present paper reviews two widely applicable and economic alternatives for odor control, Activated Sludge Recycling (ASR) and Oxidized Ammonium Recycling (OAR), by discussing their fundamentals, key operating parameters and experience from the available pilot and field studies. Both technologies present high application potential using readily available plant by-products with a minimum plant upgrading, and low investment and operating costs, contributing to the sustainability and economic efficiency of odor control at wastewater treatment facilities.

  16. Occurrence, distribution, and potential influencing factors of sewage sludge components derived from nine full-scale wastewater treatment plants of Beijing, China.

    PubMed

    Wang, Xu; Li, Meiyan; Liu, Junxin; Qu, Jiuhui

    2016-07-01

    Millions of tons of waste activated sludge (WAS) produced from biological wastewater treatment processes cause severe adverse environmental consequences. A better understanding of WAS composition is thus very critical for sustainable sludge management. In this work, the occurrence and distribution of several fundamental sludge constituents were explored in WAS samples from nine full-scale wastewater treatment plants (WWTPs) of Beijing, China. Among all the components investigated, active heterotrophic biomass was dominant in the samples (up to 9478mg/L), followed by endogenous residues (6736mg/L), extracellular polymeric substances (2088mg/L), and intracellular storage products (464mg/L) among others. Moreover, significant differences (p<0.05) were observed in composition profiles of sludge samples among the studied WWTPs. To identify the potential parameters affecting the variable fractions of sludge components, wastewater source as well as design and operational parameters of WWTPs were studied using statistical methods. The findings indicated that the component fraction of sewage sludge depends more on wastewater treatment alternatives than on wastewater characteristics among other parameters. A principal component analysis was conducted, which further indicated that there was a greater proportion of residual inert biomass in the sludge produced by the combined system of the conventional anaerobic/anoxic/oxic process and a membrane bioreactor. Additionally, a much longer solids retention time was also found to influence the sludge composition and induce an increase in both endogenous inert residues and extracellular polymeric substances in the sludge.

  17. Influence of Continuous Flow Microwave Pre-Treatment on Anaerobic Digestion of Secondary Thickened Sludge for Sustainable Energy Recovery in Sewage Treatment Plant

    NASA Astrophysics Data System (ADS)

    Hephzibah, D.; Kumaran, P.; Saifuddin, N. M.

    2016-03-01

    This work elucidates the effects of pre-treatment of secondary thickened sludge (STS) for enhancement of biogas production that has great potential to generate energy for the utilization of the sewage treatment plant (STP) itself. Microwave pre-treatment has been adopted for this study. Experiment works have been designed and conducted to examine the effectiveness of continuous flow microwave pre-treatment on the solubility of STS, digestibility of STS and biogas production at a power level of 80 W for 5, 10 and 15 minutes. A few characteristics of the sewage sludge were monitored daily to identify the effect of pre-treatment on the sludge. The soluble chemical oxygen demand (SCOD)/total chemical oxygen demand (TCOD) ratio increased by 0.1, 1.0 and 1.8%, while the volatile fatty acids (VFA) concentration of the pre-treated sludge improved by 4.4, 5.1, 5.9% at the irradiation time of 5, 10 and 15 minutes, respectively at a microwave power level of 80 W. Besides that, the digestate also indicates that the pre-treated sludge undergoes efficient VS removal and TCOD removal after anaerobic digestion compared to the untreated sludge. Moreover, the biogas quantity increased by an average of 19.2, 24.1 and 32.2% in 5, 10 and 15 minutes irradiation time respectively compared to the untreated sludge. The additional quantity of biogas generated has shown a great potential for sustainable energy generation that can be utilized internally by the STP.

  18. Improvement of activated sludge resistance to shock loading by fungal enzyme addition during textile wastewater treatment.

    PubMed

    Manai, Imène; Miladi, Baligh; El Mselmi, Abdellatif; Hamdi, Moktar; Bouallagui, Hassib

    2017-04-01

    The effects of the additions of the fungal enzymatic extract were investigated in relation to the treatment of real textile wastewater (RTW) by the activated sludge process (ASP). The used enzyme cocktail was produced by a new isolated fungal Chaetomium globosum IMA1. The system that was operated with enzyme addition showed a better chemical oxygen demand (COD) removal efficiency (95%) compared to the control system (75%). In addition, the improvement of color removal (OD620) efficiencies was around 15%, when the newly consortium fungal enzymes was added. As the organic loading rate (OLR) increased from 0.33 g to 0.66 g COD L(-1) d(-1), a decrease in the performance of the two reactors was observed by monitoring the quality of treated effluents. However, the ASP working with enzyme addition showed a strong resistance to shock loadings and restored after few days compared to the control system, which was strongly inhibited. In fact, the enzyme addition improved the sludge volume index (SVI) and the activity of microorganisms. A high activity of laccase (300 U.L(-1)) enzyme was observed throughout the decolorization process in the improved system.

  19. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor.

    PubMed

    Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y

    2008-12-01

    Conventional activated sludge wastewater treatment plants currently produce a large quantity of excess sludge. To reduce this sludge production and to improve sludge characteristics in view of their subsequent elimination, an ultrasonic cell disintegration process was studied. In a lab-scale continuous flow pilot plant, part of the return sludge was sonicated by low-frequency and high-powered ultrasound and then recycled to the aeration tank. Two parallel lines were used: one as a control and the other as an assay with ultrasonic treatment. The reactors were continuously fed with synthetic domestic wastewater with a COD (chemical oxygen demand) of approximately 0.5 g l(-) corresponding to a daily load of 0.35-0.50 kg COD kg(-1) TS d(-1). Removal efficiencies (carbon, particles), excess sludge production and sludge characteristics (particle size distribution, mineralization, respiration rate, biological component) were measured every day during the 56-day experiment. This study showed that whilst organic removal efficiency did not deteriorate, excess sludge production was decreased by about 25-30% by an ultrasonic treatment. Several hypotheses are advanced: (i) the treatment made a part of the organic matter soluble as a consequence of the floc disintegration, and optimised the conversion of the carbonaceous pollutants into carbon dioxide and (ii) the treatment modified the physical characteristics of sludge by a mechanical effect: floc size was reduced, increasing the exchange surface and sludge activity. The originality of this study is that experiments were conducted in a continuous-flow activated sludge reactor rather than in a batch reactor.

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

    PubMed

    Escolà Casas, Mònica; Bester, Kai

    2015-02-15

    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.

  1. Fenton peroxidation improves the drying performance of waste activated sludge.

    PubMed

    Dewil, Raf; Baeyens, Jan; Neyens, Elisabeth

    2005-01-31

    Advanced sludge treatment processes (AST) reduce the amount of sludge produced and improve the dewaterability, thus probably also affecting the heat transfer properties and the drying characteristics of the sludge. This paper studies the influence of the Fenton peroxidation on the thermal conductivity of the sludge. Results demonstrate that the Fenton's peroxidation positively influences the sludge cake consistency and hence enhances the mechanical dewaterability and the drying characteristics of the dewatered sludge. For the two sludges used in this study, i.e. obtained from the wastewater treatment plants (WWTP) of Tienen and Sint-Niklaas--the dry solids content of the mechanically dewatered sludge increased from 22.5% to 40.3% and from 18.7% to 35.2%, respectively. The effective thermal conductivity k(e) of the untreated and the peroxidized sludges is measured and used to determine the heat transfer coefficient h(s). An average improvement for k(e) of 16.7% (Tienen) and 5.8% (Sint-Niklaas) was observed. Consequently the value of h(s) increased with 15.6% (Tienen) and 5.0% (Sint-Niklaas). This increased heat transfer coefficient in combination with the increased dewaterability has direct implications on the design of sludge dryers. A plate-to-plate calculation of a multiple hearth dryer illustrates that the number of plates required to dry the peroxidized sludge to 90% DS is less than half the number of plates needed to dry untreated sludge. This results in reduced dryer dimensions or a higher capacity for an existing dryer of given dimensions.

  2. Levels and distribution patterns of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China.

    PubMed

    Zeng, Lixi; Wang, Thanh; Ruan, Ting; Liu, Qian; Wang, Yawei; Jiang, Guibin

    2012-01-01

    Short chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutant candidates in the Stockholm Convention and are receiving more and more attentions worldwide. In general, concentrations of contaminants in sewage sludge can give an important indication on their pollution levels at a local/regional basis. In this study, SCCPs were investigated in sewage sludge samples collected from 52 wastewater treatment plants in China. Concentrations of total SCCPs (ΣSCCPs) in sludge were in the range of 0.80-52.7 μg/g dry weight (dw), with a mean value of 10.7 μg/g dw. Most of SCCPs in the sludge samples showed a similar congener distribution patterns, and C(11) and Cl(7,8) were identified as the dominant carbon and chlorine congener groups. Significant linear relationships were found among different SCCP congener groups (r(2) ≥ 0.9). High concentrations of SCCPs in sewage sludge imply that SCCPs are widely present in China.

  3. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China

    PubMed Central

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-01-01

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index Igeo and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. Igeo classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes. PMID:26690464

  4. Biomethanization of mixtures of fruits and vegetables solid wastes and sludge from a municipal wastewater treatment plant.

    PubMed

    Gomez-Lahoz, C; Fernández-Giménez, B; Garcia-Herruzo, F; Rodriguez-Maroto, J M; Vereda-Alonso, C

    2007-03-01

    The possible management of Fruit and Vegetable Solid Wastes (FVSWs) through their simultaneous digestion with the primary sludge of Municipal Wastewater Treatment plants is investigated. This alternative allows the recovery of energy and a solid product that can be used as an amendment for soils that generated the residue, while is not expensive. Results indicate that the ratio of FVSWs to sludge and the pH control are the main variables determining the methane production and concentration. NaHCO3 was selected to achieve the pH control. The results for a ratio of 50% sludge together with 10 g NaHCO3/kg of residue are among the best obtained, with a methane yield of about 90 L per kg of volatile solids, and a methane concentration of 40% (v/v) of the biogas. A 50% reduction of the total solids; 21% reduction of the volatile solids (in terms of total solids); and a pH value of the sludge, which is 6.9 indicate that the digested sludge can be a good material for soil amendment.

  5. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China.

    PubMed

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-12-11

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index I(geo) and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. I(geo) classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes.

  6. REVISING/UPDATING EPA 625/1-79-011, PROCESS DESIGN MANUAL FOR SLUDGE TREATMENT AND DISPOSAL

    EPA Science Inventory

    The US Environmental Protection Agency (EPA) wishes to revise/update its very large and comprehensive 1979 Process Design Manual for Sludge Treatment and Disposal, EPA 625/1-79-011. As you might imagine the task is not trivial, as already in 1979 the original manual cost more tha...

  7. Monitoring Precursor 16S rRNAs of Acinetobacter spp. in Activated Sludge Wastewater Treatment Systems

    PubMed Central

    Oerther, Daniel B.; Pernthaler, Jakob; Schramm, Andreas; Amann, Rudolf; Raskin, Lutgarde

    2000-01-01

    Recently, Cangelosi and Brabant used oligonucleotide probes targeting the precursor 16S rRNA of Escherichia coli to demonstrate that the levels of precursor rRNA were more sensitive to changes in growth phase than the levels of total rRNA (G. A. Cangelosi and W. H. Brabant, J. Bacteriol. 179:4457–4463, 1997). In order to measure changes in the levels of precursor rRNA in activated sludge systems, we designed oligonucleotide probes targeting the 3′ region of the precursor 16S rRNA of Acinetobacter spp. We used these probes to monitor changes in the level of precursor 16S rRNA during batch growth of Acinetobacter spp. in Luria-Bertani (LB) medium, filtered wastewater, and in lab- and full-scale wastewater treatment systems. Consistent with the previous reports for E. coli, results obtained with membrane hybridizations and fluorescence in situ hybridizations with Acinetobacter calcoaceticus grown in LB medium showed a more substantial and faster increase in precursor 16S rRNA levels compared to the increase in total 16S rRNA levels during exponential growth. Diluting an overnight culture of A. calcoaceticus grown in LB medium with filtered wastewater resulted in a pattern of precursor 16S rRNA levels that appeared to follow diauxic growth. In addition, fluorescence in situ hybridizations with oligonucleotide probes targeting total 16S rRNA and precursor 16S rRNA showed that individual cells of A. calcoaceticus expressed highly variable levels of precursor 16S rRNA when adapting from LB medium to filtered sewage. Precursor 16S rRNA levels of Acinetobacter spp. transiently increased when activated sludge was mixed with influent wastewater in lab- and full-scale wastewater treatment systems. These results suggest that Acinetobacter spp. experience a change in growth activity within wastewater treatment systems. PMID:10788395

  8. Pollutant element forms within sludges generated by treatment of two acid mine waters with lime, inorganic sulfide and sulfate reducing bacteria

    SciTech Connect

    Chatham, B.; Diebold, F.

    1995-10-01

    One of the research projects within the Mine Waste Technology Pilot Program conducted at Montana Tech under subcontract to MSE, Inc., Butte, MT is entitled {open_quotes}Formation, Properties and Stability of Sludge Generated During Treatment of Acid Mine Water.{close_quotes} One area of study within this activity is the determination of the element-solid associations within the three sludges being studied, namely, a lime initiated sludge, an inorganic sulfide initiated sludge and a sulfate reducing bacteria initiated sludge. These sludges are formed from treatment of two acid mine waters; one from an abandoned metal sulfide open pit mine (the Berkeley Pit in Butte, MT) and another from an abandoned metal sulfide underground mine (the Crystal Mine NW of Basin, MT). A sequential leaching scheme has been used to determine the form of the pollutant elements (Cu, Zn, Cd, Fe, Mn, and As) within these sludges. Significant differences are observed between these pollutant elements for each sludge. These data are interpreted in terms of the potential for release of the pollutant elements within a sludge containment pond storage system.

  9. Concentration of soluble and nonsoluble zinc-based impurities by unidirectional freezing: basis for a method of sludges treatment.

    PubMed

    Gay, Guillaume; Azouni, Aza

    2007-08-01

    Heavy metals are known to be significant pollutants in sludges produced by wastewater treatment. A newtechnique to make the metallic contaminants migrate is to submit such sludges to a slow freezing in order to purify the frozen region and to concentrate impurities in the non-frozen zone. In this paper, we apply this method to model contaminated sludges consisting of clayey suspensions charged with a heavy metal (zinc). The effect of some physicochemical parameters (zinc and clay concentrations, pH) on the effectiveness of the method is experimentally investigated. The pH is the most relevant parameter and the highest purification rate (approximately 80%) is obtained for pH approximately 9.

  10. Monitoring of total metal concentration in sludge samples: case study for the mechanical-biological wastewater treatment plant in Velika Gorica, Croatia.

    PubMed

    Filipović, Josip; Grčić, Ivana; Bermanec, Vladimir; Kniewald, Goran

    2013-03-01

    In this paper, monitoring of total metal concentration in sludge samples from wastewater treatment process is elaborated. The presented results summarize the analyses of sludge samples in a period from 2008 to 2012. Possible sources of pollutions are given. Primarily, waste solid samples were collected from different pretreatment steps: (A) coarse grid, (B) fine grid and (C) aerated sand grease grid. Samples of A and B followed a repeatable pattern in 2008 and 2010. According to the results from 2008, samples of C contained measurable concentration of the following metals (mg/kg dry matter): Zn (21), Ni (1.05) and Ba (14.9). Several types of sludge samples were analyzed: fresh raw sludge (PS; 6-12 hour old), the sludge from the digester for anaerobic sludge treatment (DS; 48-72 hour old), samples from lagoons where the sludge is temporarily deposited (DOS and DOSold; 30-120 days) and sludge samples from agricultural areas (AA; aged over 180 days). Additionally, samples of dehydrated sludge (DEHS and DEHSold; 90-180 days) were collected upon construction of equipment for sludge dehydration in 2011. An analysis of total metal concentrations for Cu, Zn, Cr, Pb, Ni, Hg, Cd, Ba, As, Se, Sb, Co, Mo, Fe and Mn was performed by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). The most recent results (year 2011) indicated a high concentration of heavy metals in PS samples, exceeding the MCLs (mg/kg dry matter): Cu (2122), Zn (5945), Hg (13.67) and Cd (6.29). In 2012 (until July), only a concentration of Cu exceeded MCL (928.75 and 1230.5 in DS and DEHS, respectively). A composition of sludge was variable through time, offering the limited possibility for future prediction. The sludge is being considered as a hazardous waste and a subject of discussion regarding disposal.

  11. Effects of calcined aluminum salts on the advanced dewatering and solidification/stabilization of sewage sludge.

    PubMed

    Zhen, Guangyin; Yan, Xiaofei; Zhou, Haiyan; Chen, Hua; Zhao, Tiantao; Zhao, Youcai

    2011-01-01

    The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl2, Na2SO4 and CaSO4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS(0) obtained with 5% AS and 10% CaSO4 of AS by weight presented a moisture contents below 50%-60% and a compressive strength of (51.32 +/- 2.9) kPa after 5-7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry-differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO3) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.

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

    PubMed

    Luostarinen, S; Luste, S; Sillanpää, M

    2009-01-01

    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 degrees C. Grease trap sludge had high methane production potential (918 m(3)/tVS(added)), 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 two materials was found feasible up to grease trap sludge addition of 46% of feed volatile solids (hydraulic retention time 16d; maximum organic loading rate 3.46 kgVS/m(3)d). Methane production was significantly higher and no effect on the characteristics of the digested material was noticed as compared to digesting sewage sludge alone. At higher grease trap sludge additions (55% and 71% of feed volatile solids), degradation was not complete and methane production either remained the same or decreased.

  13. New Treatment in Advanced Thyroid Cancer

    PubMed Central

    Giuffrida, Dario; Prestifilippo, Angela; Scarfia, Alessia; Martino, Daniela; Marchisotta, Stefania

    2012-01-01

    Thyroid cancer is the most common endocrine tumor. Thyroidectomy, radioactive iodine, and TSH suppression represent the standard treatment for differentiated thyroid cancer. Since chemotherapy has been shown to be unsuccessful in case of advanced thyroid carcinomas, the research for new therapies is fundamental. In this paper, we reviewed the recent literature reports (pubmed, medline, EMBASE database, and abstracts published in meeting proceedings) on new treatments in advanced nonmedullary and medullary thyroid carcinomas. Studies of many tyrosine kinase inhibitors as well as antiangiogenic inhibitors suggest that patients with thyroid cancer could have an advantage with new target therapy. We summarized both the results obtained and the toxic effects associated with these treatments reported in clinical trials. Reported data in this paper are encouraging, but further trials are necessary to obtain a more effective result in thyroid carcinoma treatment. PMID:23133451

  14. Calculation of energy recovery and greenhouse gas emission reduction from palm oil mill effluent treatment by an anaerobic granular-sludge process.

    PubMed

    Show, K Y; Ng, C A; Faiza, A R; Wong, L P; Wong, L Y

    2011-01-01

    Conventional aerobic and low-rate anaerobic processes such as pond and open-tank systems have been widely used in wastewater treatment. In order to improve treatment efficacy and to avoid greenhouse gas emissions, conventional treatment can be upgraded to a high performance anaerobic granular-sludge system. The anaerobic granular-sludge systems are designed to capture the biogas produced, rendering a potential for claims of carbon credits under the Kyoto Protocol for reducing emissions of greenhouse gases. Certified Emission Reductions (CERs) would be issued, which can be exchanged between businesses or bought and sold in international markets at the prevailing market prices. As the advanced anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they render more carbon credits than other conventional anaerobic systems. In addition to efficient waste degradation, the carbon credits can be used to generate revenue and to finance the project. This paper presents a scenario on emission avoidance based on a methane recovery and utilization project. An example analysis on emission reduction and an overview of the global emission market are also outlined.

  15. Conductive heating and microwave hydrolysis under identical heating profiles for advanced anaerobic digestion of municipal sludge.

    PubMed

    Mehdizadeh, Seyedeh Neda; Eskicioglu, Cigdem; Bobowski, Jake; Johnson, Thomas

    2013-09-15

    Microwave (2.45 GHz, 1200 W) and conventional heating (custom pressure vessel) pretreatments were applied to dewatered municipal waste sludge (18% total solids) using identical heating profiles that span a wide range of temperatures (80-160 °C). Fourteen lab-scale semi-continuous digesters were set up to optimize the energy (methane) output and sludge retention time (SRT) requirements of untreated (control) and thermally pretreated anaerobic digesters operated under mesophilic and thermophilic temperatures. Both pretreatment methods indicated that in the pretreatment range of 80-160 °C, temperature was a statistically significant factor (p-value < 0.05) for increasing solubilization of chemical oxygen demand and biopolymers (proteins, sugars, humic acids) of the waste sludge. However, the type of pretreatment method, i.e. microwave versus conventional heating, had no statistically significant effect (p-value >0.05) on sludge solubilization. With the exception of the control digesters at a 5-d SRT, all control and pretreated digesters achieved steady state at all three SRTs, corresponding to volumetric organic loading rates of 1.74-6.96 g chemical oxygen demand/L/d. At an SRT of 5 d, both mesophilic and thermophilic controls stopped producing biogas after 20 d of operation with total volatile fatty acids concentrations exceeding 1818 mg/L at pH <5.64 for mesophilic and 2853 mg/L at pH <7.02 for thermophilic controls, while the pretreated digesters continued producing biogas. Furthermore, relative (to control) organic removal efficiencies dramatically increased as SRT was shortened from 20 to 10 and then 5 d, indicating that the control digesters were challenged as the organic loading rate was increased. Energy analysis showed that, at an elevated temperature of 160 °C, the amount of methane recovered was not enough to compensate for the energy input. Among the digesters with positive net energy productions, control and pretreated digesters at 80 °C were more

  16. Co-digestion of organic solid waste and sludge from sewage treatment.

    PubMed

    Edelmann, W; Engeli, H; Gradenecker, M

    2000-01-01

    Solid organic wastes were codigested together with sludge of a sewage treatment plant (STP). In the practical part of the study, a plant to pretreat the organic solid wastes provided by local super markets was constructed at the STP of Frutigen, Switzerland. Up to more than 1 cubic metre of wastes was added to the fermenter of the STP every day. Data collected during 14 months of practical works, showed that for raw fruit and vegetable wastes a two step pretreatment is necessary: First the wastes were chopped and afterwards reduced to a size of 1-2 millimetres, in order to get a homogeneous suspension together with the primary sludge. The vegetable wastes showed excellent digestibility: They seemed to accelerate the digestion process as well as to increase the degree of the anaerobic degradation of the sludge. The energy demand for both, pretreatment and digestion, was 85 kWh/ton of fresh wastes. 20% of the energy was used for the hygienization, a step which does not seem to be necessary for this kind of waste in most of the cases, however. After using the gas for energy conversion, a net yield of 65 kWh/ton of electricity and 166 kWh/ton of heat was measured. Treating cooked kitchen wastes, the net energy production will be higher, because in this case a one step pretreatment will be sufficient. The pretreatment and treatment costs for codigestion on STP's were calculated to be in the range of 55 US$/ton treating half a ton per day and 39 US$/ton treating one ton, respectively. A theoretical feasibility study showed that in Switzerland there is a short term potential on STP's for the codigestion of about 120,000 tons of biogenic wastes per year without big investments. Economic studies about codigestion on agricultural biogas plants showed that the codigestion is a must at the current energy prices, which are far too low for agricultural AD without an additional income by treating solid wastes for third parties.

  17. Optimisation of aeration for activated sludge treatment with simultaneous nitrification denitrification.

    PubMed

    Thauré, David; Lemoine, Cyrille; Daniel, Olivier; Moatamri, Nader; Chabrol, Julien

    2008-01-01

    Following a promising study at pilot scale a new aeration control law has been implemented at a full scale wastewater treatment plant displaying a conventional activated sludge process. The new control law is based on the direct measurements of ammonium and nitrate concentration in the biological tank by ion selective electrodes. This control law features a cascade of two Predictive Function Controls and calculates an optimal air flow rate to be provided to the biomass through fine bubble diffusers. The results obtained at the full scale plant confirmed the high performance of this control strategy allowing to substantially reduce the amount of diffused air while providing an easy means to manage the effluent quality to the plant operator.

  18. Selenium Speciation in Biofilms from Granular Sludge Bed Reactors Used for Wastewater Treatment

    SciTech Connect

    Hullenbusch, Eric van; Farges, Francois; Lenz, Markus; Lens, Piet; Brown, Gordon E. Jr.

    2007-02-02

    Se K-edge XAFS spectra were collected for various model compounds of Se as well as for 3 biofilm samples from bioreactors used for Se-contaminated wastewater treatment. In the biofilm samples, Se is dominantly as Se(0) despite Se K-edge XANES spectroscopy cannot easily distinguish between elemental Se and Se(-I)-bearing selenides. EXAFS spectra indicate that Se is located within aperiodic domains, markedly different to these known in monoclinc red selenium. However, Se can well occur within nanodivided domains related to monoclinic red Se, as this form was optically observed at the rim of some sludges. Aqueous selenate is then efficiently bioreduced, under sulfate reducing and methanogenic conditions.

  19. Selenium Speciation in Biofilms from Granular Sludge Bed Reactors Used for Wastewater Treatment

    SciTech Connect

    van Hullenbusch, Eric; Farges, Francois; Lenz, Markus; Lens, Piet; Brown, Gordon E., Jr.; /Stanford U., Geo. Environ. Sci. /SLAC, SSRL

    2006-12-13

    Se K-edge XAFS spectra were collected for various model compounds of Se as well as for 3 biofilm samples from bioreactors used for Se-contaminated wastewater treatment. In the biofilm samples, Se is dominantly as Se(0) despite Se K-edge XANES spectroscopy cannot easily distinguish between elemental Se and Se(-I)-bearing selenides. EXAFS spectra indicate that Se is located within aperiodic domains, markedly different to these known in monoclinic red selenium. However, Se can well occur within nanodivided domains related to monoclinic red Se, as this form was optically observed at the rim of some sludges. Aqueous selenate is then efficiently bioreduced, under sulfate reducing and methanogenic conditions.

  20. Engineering evaluation of solids/liquids separation processes applicable to sludge treatment project

    SciTech Connect

    Duncan, J.B.

    1998-08-25

    This engineering study looks at the solids/liquids separation unit operations after the acid dissolution of the K Basin sludge treatment. Unit operations considered were centrifugation, filtration (cartridge, cross flow, and high shear filtration) and gravity settling. The recommended unit operations for the solids/liquids separations are based upon the efficiency, complexity, and off-the-shelf availability and adaptability. The unit operations recommended were a Robatel DPC 900 centrifuge followed by a nuclearized 31WM cartridge filter. The Robatel DPC 900 has been successfully employed in the nuclear industry on a world wide scale. The 31WM cartridge filter has been employed for filtration campaigns in both the government and civilian nuclear arenas.

  1. Phosphorus recovery as AlPO4 from beneficially reused aluminium sludge arising from water treatment.

    PubMed

    Zhao, X H; Zhao, Y Q; Kearney, P

    2013-01-01

    The purpose of this study was to develop an efficient and, possibly, a practically operated methodology to recover phosphorus (P) from P-saturated dewatered aluminium sludge cakes (DASC) after the DASC have been beneficially reused as constructed wetlands substrate for P-rich wastewater treatment. A three-step procedure of 1) P extraction by H2SO4, 2) decolorization of extraction leachate via H2O2 oxidation, and 3) AlPO4 precipitation by pH adjustment, has been explored. The optimal conditions to form the precipitates of AlPO4 were determined, with 97% of P and 99% of Al being recovered. The obtained compounds were identified by XRD, FTIR and SEM analyses. Although the purity, structure, characteristics and production control of the compounds are worthy of further investigation, this study provides a showcase of a 'closed loop' regarding the beneficial reuse of a 'waste' and the recovery of useful elements after the reuse.

  2. Demonstration of vitrification of surrogate F006 waste-water treatment sludges

    SciTech Connect

    Bennert, D.M.; Overcamp, T.J.; Bickford, D.F.; Jantzen, C.M.; Cicero, C.A.

    1994-12-31

    A demonstration program with the focus on vitrification of surrogate formulations of Savannah River Site M-Area wastewater treatment sludges has been completed. The program utilized commercially available melting equipment, supplied by EnVitCo, Inc., and Stir Melter, Inc., located at the Clemson University Environmental Systems Engineering Laboratories. Over 2000 kg of glass was manufactured in a series of five separate tests with four formulations. Glasses were characterized by Toxicity Characteristic Leaching Procedure (TCLP) and the Product Consistency Test (PCT), with all glasses showing leach characteristics better than Land Disposal Requirements (LDR) for corresponding F006 waste (TCLP) and benchmark environmental assessment glasses (PCT). Offgas sampling by EPA Method 5 was conducted, including chemical analysis of filter residue and impinger solution. Data is presented on glass leaching, offgas sampling, phase separation, and melter performance.

  3. Integrated nanofiltration and upflow anaerobic sludge blanket treatment of textile wastewater for in-plant reuse.

    PubMed

    Gomes, Arlindo Canigo; Gonçalves, Isolina Cabral; de Pinho, Maria Norberta; Porter, John Jefferson

    2007-05-01

    The filtration characteristics of simulated dyeing effluents containing Acid Orange 7, sodium sulfate, and a pH buffer made of acetic acid and sodium acetate is described using a commercially available nanofiltration membrane. The original membrane filtration properties were characterized with deionized water to provide a baseline of membrane performance. At high volumetric concentration of the test solutions, greater than 98% rejection of dye and sodium sulfate were obtained. Rejection of buffering chemicals was approximately 50% in all experiments, giving a permeate water not suitable for reuse in most dyeing operations. The final composite concentrate had a chemical oxygen demand (COD) value > 2000 mg/L. No problems were encountered with anaerobic treatment of the concentrate obtained from the dyeing wastewater. Adjusting the sulfate concentration to give COD-to-sulfate ratios to 2.9, 5.4, and 18.2 in the reactor feed had no significant alterations in the performance of the upflow anaerobic sludge blanket reactor.

  4. Analysis of toxicity of leachates from coal liquefaction wastewater treatment sludge

    SciTech Connect

    Dahlberg, M.D.; Ruppel, T.C.

    1985-03-01

    The disposal requirements for wastewater treatment sludge from coal liquefaction plants will be determined by toxicity tests established by the Environmental Protection Agency (EPA) to enforce the Resource Conservation and Recovery Act (RCRA). Concentrations of eight elements in samples from a noncommercial plant were well below the standards used in the EP (extraction procedure) test of the EPA. Toxicity bioassays with Daphnia magna supported the results of the EP tests. Leachates generated according to the American Society for Testing and Materials extraction procedure (ASTM D-3987) were also tested. Concentrations of RCRA elements were frequently below the minimum detectable concentrations, and no differences in toxicity of the EP and ASTM extracts were evident. 17 references, 3 tables.

  5. Cost estimation and economical evaluation of three configurations of activated sludge process for a wastewater treatment plant (WWTP) using simulation

    NASA Astrophysics Data System (ADS)

    Jafarinejad, Shahryar

    2016-07-01

    The activated sludge (AS) process is a type of suspended growth biological wastewater treatment that is used for treating both municipal sewage and a variety of industrial wastewaters. Economical modeling and cost estimation of activated sludge processes are crucial for designing, construction, and forecasting future economical requirements of wastewater treatment plants (WWTPs). In this study, three configurations containing conventional activated sludge (CAS), extended aeration activated sludge (EAAS), and sequencing batch reactor (SBR) processes for a wastewater treatment plant in Tehran city were proposed and the total project construction, operation labor, maintenance, material, chemical, energy and amortization costs of these WWTPs were calculated and compared. Besides, effect of mixed liquor suspended solid (MLSS) amounts on costs of WWTPs was investigated. Results demonstrated that increase of MLSS decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS. In addition, increase of this value increases the total operation, maintenance and energy costs, but does not affect chemical cost of WWTPs containing EAAS and CAS.

  6. Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process.

    PubMed

    Xia, Yi; He, Pin Jing; Pu, Hong Xia; Lü, Fan; Shao, Li Ming; Zhang, Hua

    2017-01-01

    This research focused on the inhibitory effects of Ca on the aerobic biological treatment of landfill leachate containing extremely high Ca concentrations. When the Ca concentration in leachate to be treated was more than 4500 mg l(-1), the total organic carbon removal rate was significantly reduced and the processing time to achieve the same removal efficiency was 1.4 times that in the control treatment without added Ca. In contrast, the total nitrogen and ammonia nitrogen (NH4(+)-N) removal efficiencies were positively related to the Ca concentration, increasing from 65.2% to 81.2% and from 69.2% to 83.7%, respectively, when the dosage of added Ca increased from zero to 8000 mg l(-1). During aerobic treatment, the reductions of solution Ca concentration were in the range of 1003-2274 mg l(-1) and were matched with increases in the Ca content in the residual sludge. The inhibition threshold of Ca in the leachate treated by the activated sludge process appeared to be 4500 mg l(-1), which could be realized by controlling the influent Ca concentration and using an appropriate sludge return ratio in the activated sludge process.

  7. Co-digestion of cultivated microalgae and sewage sludge from municipal waste water treatment.

    PubMed

    Olsson, Jesper; Feng, Xin Mei; Ascue, Johnny; Gentili, Francesco G; Shabiimam, M A; Nehrenheim, Emma; Thorin, Eva

    2014-11-01

    In this study two wet microalgae cultures and one dried microalgae culture were co-digested in different proportions with sewage sludge in mesophilic and thermophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of sewage sludge alone. The results showed that co-digestion with both wet and dried microalgae, in certain proportions, increased the biochemical methane potential (BMP) compared with digestion of sewage sludge alone in mesophilic conditions. The BMP was significantly higher than the calculated BMP in many of the mixtures. This synergetic effect was statistically significant in a mixture containing 63% (w/w VS based) undigested sewage sludge and 37% (w/w VS based) wet algae slurry, which produced 23% more methane than observed with undigested sewage sludge alone. The trend was that thermophilic co-digestion of microalgae and undigested sewage sludge did not give the same synergy.

  8. Limitations for heavy metal release during thermo-chemical treatment of sewage sludge ash

    SciTech Connect

    Nowak, Benedikt

    2011-06-15

    Phosphate recycling from sewage sludge can be achieved by heavy metal removal from sewage sludge ash (SSA) producing a fertilizer product: mixing SSA with chloride and treating this mixture (eventually after granulation) in a rotary kiln at 1000 {+-} 100 deg. C leads to the formation of volatile heavy metal compounds that evaporate and to P-phases with high bio-availability. Due to economical and ecological reasons, it is necessary to reduce the energy consumption of this technology. Generally, fluidized bed reactors are characterized by high heat and mass transfer and thus promise the saving of energy. Therefore, a rotary reactor and a fluidized bed reactor (both laboratory-scale and operated in batch mode) are used for the treatment of granulates containing SSA and CaCl{sub 2}. Treatment temperature, residence time and - in case of the fluidized bed reactor - superficial velocity are varied between 800 and 900 deg. C, 10 and 30 min and 3.4 and 4.6 m s{sup -1}. Cd and Pb can be removed well (>95 %) in all experiments. Cu removal ranges from 25% to 84%, for Zn 75-90% are realized. The amount of heavy metals removed increases with increasing temperature and residence time which is most pronounced for Cu. In the pellet, three major reactions occur: formation of HCl and Cl{sub 2} from CaCl{sub 2}; diffusion and reaction of these gases with heavy metal compounds; side reactions from heavy metal compounds with matrix material. Although, heat and mass transfer are higher in the fluidized bed reactor, Pb and Zn removal is slightly better in the rotary reactor. This is due the accelerated migration of formed HCl and Cl{sub 2} out of the pellets into the reactor atmosphere. Cu is apparently limited by the diffusion of its chloride thus the removal is higher in the fluidized bed unit.

  9. Microwave treatment of faecal sludge from intensively used toilets in the slums of Nairobi, Kenya.

    PubMed

    Mawioo, Peter M; Hooijmans, Christine M; Garcia, Hector A; Brdjanovic, Damir

    2016-12-15

    Toilet facilities in highly dense areas such as the slum and emergency settlements fill up rapidly; thus, requiring frequent emptying. Consequently, big quantities of fresh faecal sludge (FS) containing large amounts of pathogens are generated. Fast and efficient FS treatment technologies are therefore required for safe treatment and disposal of the FS in such conditions. This study explores the applicability of a microwave (MW) technology for the treatment of fresh FS obtained from urine-diverting dry toilets placed in slum settlements in Nairobi, Kenya. Two sample fractions containing 100 g and 200 g of FS were exposed to MW irradiation at three input MW power levels of 465, 1085 and 1550 W at different exposure times ranging from 0.5 to 14 min. The variation in the FS temperature, pathogen reduction via the destruction of E. coli and Ascaris lumbricoides eggs, and vol/wt reduction were measured during the MW treatment. It was demonstrated that the MW technology can rapidly and efficiently achieve complete reduction of E. coli and Ascaris lumbricoides eggs, and over 70% vol/wt reduction in the fresh FS. Furthermore, the successful evaluation of the MW technology under real field conditions demonstrated that MW irradiation can be applied for rapid treatment of fresh FS in situations such as urban slum and emergency conditions.

  10. A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems.

    PubMed

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

    2008-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-01-01

    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.

  12. Improving the biotreatment of hydrocarbons-contaminated soils by addition of activated sludge taken from the wastewater treatment facilities of an oil refinery.

    PubMed

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

    2003-01-01

    Addition of activated sludge taken from the wastewater treatment facilities of an oil refinery to a soil contaminated with oily sludge stimulated hydrocarbon biodegradation in microcosms, bioreactors and biopile. Microcosms containing 50 g of soil to which 0.07% (w/w) of activated sludge was added presented a higher degradation of alkanes (80% vs 24%) and polycyclic aromatic hydrocarbons (PAHs) (77% vs 49%) as compared to the one receiving only water, after 30 days of incubation at room temperature. Addition of ammonium nitrate or sterile sludge filtrate instead of activated sludge resulted in a similar removal of PAHs but not of alkanes suggesting that the nitrogen contained in the activated sludge plays a major role in the degradation of PAHs while microorganisms of the sludge are active against alkanes. Addition of sludge also stimulated hydrocarbon biodegradation in 10-kg bioreactors operated during 60 days and in a 50-m3 biopile operated during 126 days. This biopile treatment allowed the use of the soil for industrial purpose based on provincial regulation ("C" criteria). In contrast, the soil of the control biopile that received only water still exceeded C criteria for C10-C50 hydrocarbons, total PAHs, chrysene and benzo[a]anthracene. The stimulation effect of sludge was stronger on the 4-rings than on 2-rings PAHs. The soil of the biopile that received sludge was 4-5 times less toxic than the control. These results suggest that this particular type of activated sludge could be used to increase the efficiency of the treatment of hydrocarbon-contaminated soils in a biopile.

  13. Systems for the treatment of organic material and particularly sewage sludge

    SciTech Connect

    Schimel, K.A.

    1983-08-30

    Anaerobic digestion of organic material, particularly biological sludge, such as sewage sludge, is carried out in a closed system having a first digestion tank and a second concentration and partial digestion tank. The concentrated and partially digested sludge is fed to the first tank where it is maintained under vacuum such that an active zone of organic material undergoing digestion is detained therein for a long period of time. The digested sludge is withdrawn against the vacuum and has approximately 80 to 90% of the organic solids therein mineralized; thus simplifying dewatering and ultimate disposal of the sludge. Pathogens including viruses are also removed from the digested sludge. Denitrification takes place in the vacuum digester tank and gas consisting essentially of nitrogen is removed. Return sludge from the vacuum digester and influent sludge is fed into the second or concentrator tank to facilitate reseeding with anaerobic organisms. Both tanks are provided with passageways which are coterminous near the upper ends of the tanks and provided with baffles which direct the flow to be in opposite directions in the passageways, thus providing for stripping of the gas and solid-liquid separation. Gas consisting essentially of methane and carbon dioxide is produced from the second tank. Supernatant from the second tank may be recirculated to the source of the sludge to facilitate degradation of remaining organic contaminants.

  14. Probabilistic assessment of environmental exposure to the polycyclic musk, HHCB and associated risks in wastewater treatment plant mixing zones and sludge amended soils in the United States.

    PubMed

    Federle, Thomas; Sun, Ping; Dyer, Scott; Kiel, Brian

    2014-09-15

    The objective of this work was to conduct an environmental risk assessment for the consumer use of the polycyclic musk, HHCB (CAS No. 1222-05-5) in the U.S. focusing on mixing zones downstream from municipal wastewater treatment plants (WWTPs) and sludge amended soils. A probabilistic exposure approach was utilized combining statistical distributions of effluent and sludge concentrations for the U.S. WWTPs with distributions of mixing zone dilution factors and sludge loading rates to soil to estimate HHCB concentrations in surface waters and sediments below WWTPs and sludge amended soils. These concentrations were then compared to various toxicity values. Measured concentrations of HHCB in effluent and sludge from a monitoring program of 40 WWTPs across the U.S. formed the basis for estimating environmental loadings. Based upon a Monte Carlo analysis, the probability of HHCB concentrations being below the PNEC (predicted no effect concentration) for pelagic freshwater organisms was greater than or equal to 99.87% under both mean and low flow regimes. Similarly, the probability of HHCB concentrations being less than the PNEC for freshwater sediment organisms was greater than or equal to 99.98%. Concentrations of HHCB in sludge amended soils were estimated for single and repeated annual sludge applications with tilling of the sludge into the soil, surface application without tilling and a combination reflecting current practice. The probability of soil HHCB concentrations being below the PNEC for soil organisms after repeated sludge applications was 94.35% with current sludge practice. Probabilistic estimates of HHCB exposures in surface waters, sediments and sludge amended soils are consistent with the published values for the U.S. In addition, the results of these analyses indicate that HHCB entering the environment in WWTP effluent and sludge poses negligible risk to aquatic and terrestrial organisms in nearly all exposure scenarios.

  15. Sludge from paper mill effluent treatment as raw material to produce carbon adsorbents: An alternative waste management strategy.

    PubMed

    Jaria, Guilaine; Silva, Carla Patrícia; Ferreira, Catarina I A; Otero, Marta; Calisto, Vânia

    2017-03-01

    Pulp and paper industry produces massive amounts of sludge from wastewater treatment, which constitute an enormous environmental challenge. A possible management option is the conversion of sludge into carbon-based adsorbents to be applied in water remediation. For such utilization it is important to investigate if sludge is a consistent raw material originating reproducible final materials (either over time or from different manufacturing processes), which is the main goal of this work. For that purpose, different primary (PS) and biological sludge (BS) batches from two factories with different operation modes were sampled and subjected to pyrolysis (P materials) and to pyrolysis followed by acid washing (PW materials). All the materials were characterized by proximate analysis, total organic carbon (TOC) and inorganic carbon (IC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and N2 adsorption isotherms (specific surface area (SBET)and porosity determination). Sludge from the two factories proved to have distinct physicochemical properties, mainly in what concerns IC. After pyrolysis, the washing step was essential to reduce IC and to considerably increase SBET, yet with high impact in the final production yield. Among the materials here produced, PW materials from PS were those having the highest SBET values (387-488 m(2) g(-1)). Overall, it was found that precursors from different factories might originate final materials with distinct characteristics, being essential to take into account this source of variability when considering paper mill sludge as a raw material. Nevertheless, for PS, low variability was found between batches, which points out to the reliability of such residues to be used as precursors of carbon adsorbents.

  16. On-Site Fecal Sludge Treatment with the Anaerobic Digestion Pasteurization Latrine.

    PubMed

    Forbis-Stokes, Aaron A; O'Meara, Patrick F; Mugo, Wangare; Simiyu, Gelas M; Deshusses, Marc A

    2016-11-01

    The Anaerobic Digestion Pasteurization Latrine (ADPL) is a self-contained and energy neutral on-site sanitation system using anaerobic digestion of fecal sludge to generate biogas and then uses the biogas to pasteurize the digester effluent at 65-75°C to produce a safe effluent that can be reused locally as a fertilizer. Two ADPL systems were installed on residential plots with 17 and 35 residents in a peri-urban area outside of Eldoret, Kenya. Each system comprised three toilets built above a floating dome digester and one heat pasteurization system to sanitize the digested effluent. ADPLs are simple systems, with no moving parts and relying on gravity-induced flows. Adoption at the two sites was successful, and residents reported that the systems had little to no odor or flies. ADPLs were monitored for biogas production and temperatures in the pasteurization system. ADPLs serving 17 and 35 residents produced on average 16 and 11 Lbiogas/person/day (maximum of 20 and 15 Lbiogas/p/d), respectively. The temperature in the sterilization system was greater than 65°C on 58% and 87% of sampling days during the most stable period of operation. Treated effluent was analyzed periodically for chemical oxygen demand (COD), biochemical oxygen demand (BOD), total ammonia nitrogen (TAN), pH, and fecal coliform (FC). On average, the effluent at the two locations contained 4,540 and 6,450 mg COD/L (an 85% or 89% reduction of the estimated input), 2,050 and 3,970 mg BOD/L, and 2,420 and 4,760 mg NH3-N, respectively, and greater than 5 log reductions of FC (nondetectable) in the sterilization tank. Results from this field study show that anaerobic digestion of minimally diluted fecal sludge can provide enough energy to pasteurize digester effluent and that the ADPL may be a suitable option for on-site fecal sludge treatment.

  17. On-Site Fecal Sludge Treatment with the Anaerobic Digestion Pasteurization Latrine

    PubMed Central

    Forbis-Stokes, Aaron A.; O'Meara, Patrick F.; Mugo, Wangare; Simiyu, Gelas M.; Deshusses, Marc A.

    2016-01-01

    Abstract The Anaerobic Digestion Pasteurization Latrine (ADPL) is a self-contained and energy neutral on-site sanitation system using anaerobic digestion of fecal sludge to generate biogas and then uses the biogas to pasteurize the digester effluent at 65–75°C to produce a safe effluent that can be reused locally as a fertilizer. Two ADPL systems were installed on residential plots with 17 and 35 residents in a peri-urban area outside of Eldoret, Kenya. Each system comprised three toilets built above a floating dome digester and one heat pasteurization system to sanitize the digested effluent. ADPLs are simple systems, with no moving parts and relying on gravity-induced flows. Adoption at the two sites was successful, and residents reported that the systems had little to no odor or flies. ADPLs were monitored for biogas production and temperatures in the pasteurization system. ADPLs serving 17 and 35 residents produced on average 16 and 11 Lbiogas/person/day (maximum of 20 and 15 Lbiogas/p/d), respectively. The temperature in the sterilization system was greater than 65°C on 58% and 87% of sampling days during the most stable period of operation. Treated effluent was analyzed periodically for chemical oxygen demand (COD), biochemical oxygen demand (BOD), total ammonia nitrogen (TAN), pH, and fecal coliform (FC). On average, the effluent at the two locations contained 4,540 and 6,450 mg COD/L (an 85% or 89% reduction of the estimated input), 2,050 and 3,970 mg BOD/L, and 2,420 and 4,760 mg NH3-N, respectively, and greater than 5 log reductions of FC (nondetectable) in the sterilization tank. Results from this field study show that anaerobic digestion of minimally diluted fecal sludge can provide enough energy to pasteurize digester effluent and that the ADPL may be a suitable option for on-site fecal sludge treatment. PMID:27924135

  18. The impact of sea water flushing on biological nitrification-denitrification activated sludge sewage treatment process.

    PubMed

    Yu, S M; Leung, W Y; Ho, K M; Greenfield, P F; Eckenfelder, W W

    2002-01-01

    The process performance of the two largest activated sludge processes in Hong Kong, the Sha Tin and the Tai Po Sewage Treatment Works (STW), deteriorated in the initial period after the introduction of seawater flushing in 1995 and 1996, respectively. High effluent ammonia nitrogen (NH4-N) and total suspended solids (TSS) in excess of the discharge standards resulted from incomplete nitrification and changes in floc characteristics. A desktop study on the inhibitory effects of salinity, particularly on nitrification, was subsequently conducted using the Tai Po STW operating data. To assist the upgrade of the Sha Tin STW a five-month extensive bench-scale investigation on a simple but flexible modified Ludzack-Ettinger configuration with bio-selector was conducted to quantify the inhibitory effects due to the saline concentration. The Sha Tin STW upgrade consists of restoration of its original design capacity (conventional process) of 205,000 m3/day from its currently much reduced capacity as a Bardenpho process. Only the volume of the existing biological process and clarifier is to be utilized. The saline concentration ranges from 3,500 up to 6,500 mg Cl-/L, both daily and seasonally. High and greatly fluctuating saline concentrations have been known to inhibit nitrification. Design consideration should also be given to the peak daily and seasonal TKN loading of up to three times the average. Although the nitrifiers maximum specific growth rate was significantly reduced to a low 0.25 day(-1), the inhibition was considered to be tolerable with effluent NH4-N and NO3-N consistently at < 1 and < 6 mg/L. The bio-selector was demonstrated to be efficient in control of sludge foaming and bulking with SVI consistently < or = 125 mL/g. Results from the IAWO Model No. 1 and the hydraulic model of the secondary clarifiers allowed overall process capacity maximization. With an anoxic mass fraction of 25-30%, operating sludge age of 9-14 days and SVI < or = 125 mL/g, both the

  19. Alkali Treatment of Acidic Solution from Hanford K Basin Sludge Dissolution

    SciTech Connect

    AA Bessonov; AB Yusov; AM Fedoseev; AV Gelis; AY Garnov; CH Delegard; GM Plavnik; LN Astafurova; MS Grigoriev; NA Budantseva; NN Krot; SI Nikitenko; TP Puraeva; VP Perminov; VP Shilov

    1998-12-22

    Nitric acid solutions will be created from the dissolution of Hanford K Basin sludge. These acidic dissolver solutions must be made alkaline by treatment with NaOH solution before they are disposed to ~ the Tank Waste Remediation System on the Hanford Site. During the alkali treatments, sodium diuranate, hydroxides of iron and aluminum, and radioelements (uranium, plutonium, and americium) will precipitate from the dissolver solution. Laboratory tests, discussed here, were pefiormed to provide information on these precipitates and their precipitation behavior that is important in designing the engineering flowsheet for the treatment process. Specifically, experiments were conducted to determine the optimum precipitation conditions; the completeness of uranium, plutonium, and americium precipitation; the rate of sedimentation; and the physico-chemical characteristics of the solids formed by alkali treatment of simulated acidic dissolver solutions. These experiments also determined the redistribution of uranium, plutonium, and americium flom the sodium di~ate and iron and al&inurn hydroxide precipitates upon contact with carbonate- and EDTA-bearing simulated waste solutions. Note: EDTA is the tetrasodium salt of ethylenediaminetetraacetate.

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

    SciTech Connect

    Lombi, Enzo; Donner, Erica; Tavakkoli, Ehsan; Turney, Terence W.; Naidu, Ravi; Miller, Bradley W.; Scheckel, Kirk G.

    2013-01-14

    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.

  1. Enhancing filterability of activated sludge from landfill leachate treatment plant by applying electrical field ineffective on bacterial life.

    PubMed

    Akkaya, Gulizar Kurtoglu; Sekman, Elif; Top, Selin; Sagir, Ece; Bilgili, Mehmet Sinan; Guvenc, Senem Yazici

    2017-03-09

    The aim of this study is to investigate filterability enhancement of activated sludge supplied form a full-scale leachate treatment plant by applying DC electric field while keeping the biological operational conditions in desirable range. The activated sludge samples were received from the nitrification tank in the leachate treatment plant of Istanbul's Odayeri Sanitary Landfill Site. Experimental sets were conducted as laboratory-scale batch studies and were duplicated for 1A, 2A, 3A, 4A, and 5A of electrical currents and 2, 5, 10, 15, and 30 min of exposure times under continuous aeration. Physicochemical parameters such as temperature, pH, and oxidation reduction potential in the mixture right after each experimental set and biochemical parameters such as chemical oxygen demand, total phosphorus, and ammonia nitrogen in supernatant were analyzed to define the sets that remain in the range of ideal biological operational conditions. Later on, sludge filterability properties such as capillary suction time, specific resistance to filtration, zeta potential, and particle size were measured for remaining harmless sets. Additionally, cost analyses were conducted in respect to energy and electrode consumptions. Application of 2A DC electric field and 15-min exposure time was found to be the most favorable conditions to enhance filterability of the landfill leachate-activated sludge.

  2. Liquid products from oxidative thermal treatment of oil sludge with different oxygen concentrations of air.

    PubMed

    Shie, J L; Chang, C Y; Lin, J P; Le, D J; Wu, C H

    2001-01-01

    Oxidative thermal treatment of oil sludge with different oxygen concentrations of air by using a dynamic thermogravimetric (TG) reaction system is investigated. The experimental conditions employed are: gas flow rate of 50 cm3/min (value at 298 K) for 300 mg dry waste, a constant heating rate of 5.2 K/min, the oxygen concentrations in air of 1.09, 8.62 and 20.95 vol. % O2, and the temperature (T) range of 378-873 K. From the experimental results, the residual mass fractions (M) are about 78.95, 28.49, 8.77 and 4.13 wt. % at the oxidative T of 563, 713, 763 and 873 K for the case with 20.95 vol. % O2, respectively. The values of M with 8.62 and 1.09 vol. % O2 at T of 873 K are 4.87 and 9.44 wt. %, respectively. The distillation characteristics of the oil portion of liquid products (condensates of gas at 298 K) from the oxidative thermal treatment of oil sludge with 20.95 vol. % O2 at T of 378-873 K is close to those of commercial gasoline. Nevertheless, the liquid product contains a large amount of water. The distillation characteristics of the oil portions of liquid products with 8.62 and 1.09 vol. % O2 at T of 378-873 K are close to those of diesel and fuel oils, respectively. The oil quality with 8.62 vol. % O2 is better than that with 1.09 vol. % O2. However, the liquid product with 8.62 vol. % O2 still contains a large amount of water; nonetheless, that with 1.09 vol. % O2 is with negligible water. Compared with the oil product of nitrogen pyrolysis, the oil quality with 1.09 vol. % O2 is better. Certainly, low oxygen conditions (i.e. 1.09 vol. % O2) not only accelerate the thermal reaction of oil sludge, but also at the same time avoid or reduce the production of water. Further, from the analysis of benzene (B), ethylbenzene (E), toluene (T) and iso-xylene (X) concentrations of the oil portion of liquid products, the BETX concentrations of oil with 20.95 vol. % O2 are higher than those with 8.62 and 1.09 vol. % O2. The yields of liquid products with 20.95, 8

  3. Transport and fate of silver as polymer-stabilised nanoparticles and ions in a pilot wastewater treatment plant, followed by sludge digestion and disposal of sludge/soil mixtures: A case study.

    PubMed

    Hedberg, Jonas; Baresel, Christian; Odnevall Wallinder, Inger

    2014-01-01

    A case study of transport and changes in properties of polymer-stabilised Ag NPs is presented in this paper investigating their interaction in different treatment steps within a fully realistic pilot wastewater treatment plant (WWTP), in anaerobic digested sludge, and in soil/sludge mixtures. The fate of the same Ag NPs was tracked in these environments, hence taking the history of the Ag NPs into account. The results show that most of the Ag NPs end up in the sludge (80-100%), also after anaerobically digestion. Furthermore, the fraction of silver in the supernatant was very low after 48 h incubation with silver-containing digested sludge mixed with different soil types. However, when Ag NPs were added directly to the sludge/soil mixture, soluble silver was present in the supernatant with sandy soil, but not with clayey soil. In all, generated findings show that risk assessments and toxicological studies of Ag NPs suspensions must take into account possible chemical and particle transformations upon environmental entry, as silver in general become less soluble when transported to WWTPs and interacting with sludge, and soil.

  4. Proposal of a sequential treatment methodology for the safe reuse of oil sludge-contaminated soil.

    PubMed

    Mater, L; Sperb, R M; Madureira, L A S; Rosin, A P; Correa, A X R; Radetski, C M

    2006-08-25

    In this study sequential steps were used to treat and immobilize oil constituents of an oil sludge-contaminated soil. Initially, the contaminated soil was oxidized by a Fenton type reaction (13 wt% for H(2)O(2); 10mM for Fe(2+)). The oxidative treatment period of 80 h was carried out under three different pH conditions: 20 h at pH 6.5, 20 h at pH 4.5, and 40 h at pH 3.0. The oxidized contaminated sample (3 kg) was stabilized and solidified for 2h with clay (1 kg) and lime (2 kg). Finally, this mixture was solidified by sand (2 kg) and Portland cement (4 kg). In order to evaluate the efficiency of different processes to treat and immobilize oil contaminants of the oil sludge-contaminated soil, leachability and solubility tests were performed and extracts were analyzed according to the current Brazilian waste regulations. Results showed that the Fenton oxidative process was partially efficient in degrading the oil contaminants in the soil, since residual concentrations were found for the PAH and BTEX compounds. Leachability tests showed that clay-lime stabilization/solidification followed by Portland cement stabilization/solidification was efficient in immobilizing the recalcitrant and hazardous constituents of the contaminated soil. These two steps stabilization/solidification processes are necessary to enhance environmental protection (minimal leachability) and to render final product economically profitable. The treated waste is safe enough to be used on environmental applications, like roadbeds blocks.

  5. Treatment of real industrial wastewater using the combined approach of advanced oxidation followed by aerobic oxidation.

    PubMed

    Ramteke, Lokeshkumar P; Gogate, Parag R

    2016-05-01

    Fenton oxidation and ultrasound-based pretreatment have been applied to improve the treatment of real industrial wastewater based on the use of biological oxidation. The effect of operating parameters such as Fe(2+) loading, contact time, initial pH, and hydrogen peroxide loading on the extent of chemical oxygen demand (COD) reduction and change in biochemical oxygen demand (BOD5)/COD ratio has been investigated. The optimum operating conditions established for the pretreatment were initial pH of 3.0, Fe(2+) loading of 2.0, and 2.5 g L(-1) for the US/Fenton/stirring and Fenton approach, respectively, and temperature of 25 °C with initial H2O2 loading of 1.5 g L(-1). The use of pretreatment resulted in a significant increase in the BOD5/COD ratio confirming the production of easily digestible intermediates. The effect of the type of sludge in the aerobic biodegradation was also investigated based on the use of primary activated sludge (PAS), modified activated sludge (MAS), and activated sludge (AS). Enhanced removal of the pollutants as well as higher biomass yield was observed for MAS as compared to PAS and AS. The use of US/Fenton/stirring pretreatment under the optimized conditions followed by biological oxidation using MAS resulted in maximum COD removal at 97.9 %. The required hydraulic retention time for the combined oxidation system was also significantly lower as compared to only biological oxidation operation. Kinetic studies revealed that the reduction in the COD followed a first-order kinetic model for advanced oxidation and pseudo first-order model for biodegradation. The study clearly established the utility of the combined technology for the effective treatment of real industrial wastewater.

  6. Advanced solid-state carbon-13 nuclear magnetic resonance spectroscopic studies of sewage sludge organic matter: detection of organic "domains".

    PubMed

    Smernik, Ronald J; Oliver, Ian W; Merrington, Graham

    2003-01-01

    Two novel solid-state 13C nuclear magnetic resonance (NMR) spectroscopic techniques, PSRE (proton spin relaxation editing) and RESTORE [Restoration of Spectra via T(CH) and T(1rho)H (T One Rho H) Editing], were used to provide detailed chemical characterization of the organic matter from six Australian sewage sludges. These methods were used to probe the submicrometer heterogeneity of sludge organic matter, and identify and quantify spatially distinct components. Analysis of the T1H relaxation behavior of the sludges indicated that each sludge contained two types of organic domains. Carbon-13 PSRE NMR subspectra were generated to determine the chemical nature of these domains. The rapidly relaxing component of each sludge was rich in protein and alkyl carbon, and was identified as dead bacterial material. The slowly relaxing component of each sludge was rich in carbohydrate and lignin structures, and was identified as partly degraded plant material. The bacterial domains were shown, using the RESTORE technique, to also have characteristically rapid T(1rho)H relaxation rates. This rapid T(1rho)H relaxation was identified as the main cause of underrepresentation of these domains in standard 13C cross polarization (CP) NMR spectra of sludges. The heterogeneous nature of sewage sludge organic matter has implications for land application of sewage sludge, since the two components are likely to have different capacities for sorbing organic and inorganic toxicants present in sewage sludge, and will decompose at different rates.

  7. Sanitary Landfill. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Sharman, Ronald M.

    This lesson is an introduction to disposal of sludge by landfill. A brief explanation of the complete process is provided, including discussions of sludge suitability, site selection, method selection and operation, site closure, and ultimate reuse. The lesson includes an instructor's guide and student workbook. The instructor's guide contains a…

  8. Microbiological characterization and specific methanogenic activity of anaerobe sludges used in urban solid waste treatment

    SciTech Connect

    Sandoval Lozano, Claudia Johanna Vergara Mendoza, Marisol; Carreno de Arango, Mariela; Castillo Monroy, Edgar Fernando

    2009-02-15

    This study presents the microbiological characterization of the anaerobic sludge used in a two-stage anaerobic reactor for the treatment of organic fraction of urban solid waste (OFUSW). This treatment is one alternative for reducing solid waste in landfills at the same time producing a biogas (CH{sub 4} and CO{sub 2}) and an effluent that can be used as biofertilizer. The system was inoculated with sludge from a wastewater treatment plant (WWTP) (Rio Frio Plant in Bucaramanga-Colombia) and a methanogenic anaerobic digester for the treatment of pig manure (Mesa de los Santos in Santander). Bacterial populations were evaluated by counting groups related to oxygen sensitivity, while metabolic groups were determined by most probable number (MPN) technique. Specific methanogenic activity (SMA) for acetate, formate, methanol and ethanol substrates was also determined. In the acidogenic reactor (R1), volatile fatty acids (VFA) reached values of 25,000 mg L{sup -1} and a concentration of CO{sub 2} of 90%. In this reactor, the fermentative population was predominant (10{sup 5}-10{sup 6} MPN mL{sup -1}). The acetogenic population was (10{sup 5} MPN mL{sup -1}) and the sulphate-reducing population was (10{sup 4}-10{sup 5} MPN mL{sup -1}). In the methanogenic reactor (R2), levels of CH{sub 4} (70%) were higher than CO{sub 2} (25%), whereas the VFA values were lower than 4000 mg L{sup -1}. Substrate competition between sulphate-reducing (10{sup 4}-10{sup 5} MPN mL{sup -1}) and methanogenic bacteria (10{sup 5} MPN mL{sup -1}) was not detected. From the SMA results obtained, acetoclastic (2.39 g COD-CH{sub 4} g{sup -1} VSS{sup -1} day{sup -1}) and hydrogenophilic (0.94 g COD-CH{sub 4} g{sup -1} VSS{sup -1} day{sup -1}) transformations as possible metabolic pathways used by methanogenic bacteria is suggested from the SMA results obtained. Methanotrix sp., Methanosarcina sp., Methanoccocus sp. and Methanobacterium sp. were identified.

  9. Sewage sludge ash to phosphorus fertiliser: Variables influencing heavy metal removal during thermochemical treatment

    SciTech Connect

    Mattenberger, H.; Fraissler, G.; Brunner, T. Herk, P.; Hermann, L.

    2008-12-15

    The aim of this study was to improve the removal of heavy metals from sewage sludge ash by a thermochemical process. The resulting detoxified ash was intended for use as a raw material rich in phosphorus (P) for inorganic fertiliser production. The thermochemical treatment was performed in a rotary kiln where the evaporation of relevant heavy metals was enhanced by additives. The four variables investigated for process optimisation were treatment temperature, type of additive (KCl, MgCl{sub 2}) and its amount, as well as type of reactor (directly or indirectly heated rotary kiln). The removal rates of Cd, Cr, Cu, Ni, Pb, Zn and of Ca, P and Cl were investigated. The best overall removal efficiency for Cd, Cu, Pb and Zn could be found for the indirectly heated system. The type of additive was critical, since MgCl{sub 2} favours Zn- over Cu-removal, while KCl acts conversely. The use of MgCl{sub 2} caused less particle abrasion from the pellets in the kiln than KCl. In the case of the additive KCl, liquid KCl - temporarily formed in the pellets - acted as a barrier to heavy metal evaporation as long as treatment temperatures were not sufficiently high to enhance its reaction or evaporation.

  10. Recycling potential of air pollution control residue from sewage sludge thermal treatment as artificial lightweight aggregates.

    PubMed

    Bialowiec, Andrzej; Janczukowicz, Wojciech; Gusiatin, Zygmunt M; Thornton, Arthur; Rodziewicz, Joanna; Zielinska, Magdalena

    2014-03-01

    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.

  11. Anaerobic mesophilic treatment of cattle manure in an upflow anaerobic sludge blanket reactor with prior pasteurization.

    PubMed

    Marañón, Elena; Castrillón, Leonor; Fernández, Juan José; Fernández, Yolanda; Peláez, Ana Isabel; Sánchez, Jesús

    2006-02-01

    Different autonomous communities located in northern Spain have large populations of dairy cattle. In the case of Asturias, the greatest concentration of dairy farms is found in the areas near the coast, where the elimination of cattle manure by means of its use as a fertilizer may lead to environmental problems. The aim of the present research work was to study the anaerobic treatment of the liquid fraction of cattle manure at mesophilic temperature using an upflow anaerobic sludge blanket (UASB) reactor combined with a settler after a pasteurization process at 70 degrees C for 2 hr. The manure used in this study came from two different farms, with 40 and 200 cows, respectively. The manure from the smaller farm was pretreated in the laboratory by filtration through a 1-mm mesh, and the manure from the other farm was pretreated on the farm by filtration through a separator screw press (0.5-mm mesh). The pasteurization process removed the pathogenic microorganisms lacking spores, such as Enterococcus, Yersinia, Pseudomonas, and coliforms, but bacterial spores are only reduced by this treatment, not removed. The combination of a UASB reactor and a settler proved to be effective for the treatment of cattle manure. In spite of the variation in the organic loading rate and total solids in the influent during the experiment, the chemical oxygen demand (COD) of the effluent from the settler remained relatively constant, obtaining reductions in the COD of approximately 85%.

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

    PubMed

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

    2008-07-01

    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).

  13. The porphyrias: advances in diagnosis and treatment.

    PubMed

    Balwani, Manisha; Desnick, Robert J

    2012-11-29

    The inborn errors of heme biosynthesis, the porphyrias, are 8 genetically distinct metabolic disorders that can be classified as "acute hepatic," "hepatic cutaneous," and "erythropoietic cutaneous" diseases. Recent advances in understanding their pathogenesis and molecular genetic heterogeneity have led to improved diagnosis and treatment. These advances include DNA-based diagnoses for all the porphyrias, new understanding of the pathogenesis of the acute hepatic porphyrias, identification of the iron overload-induced inhibitor of hepatic uroporphyrin decarboxylase activity that causes the most common porphyria, porphyria cutanea tarda, the identification of an X-linked form of erythropoietic protoporphyria due to gain-of-function mutations in erythroid-specific 5-aminolevulinate synthase (ALAS2), and new and experimental treatments for the erythropoietic porphyrias. Knowledge of these advances is relevant for hematologists because they administer the hematin infusions to treat the acute attacks in patients with the acute hepatic porphyrias, perform the chronic phlebotomies to reduce the iron overload and clear the dermatologic lesions in porphyria cutanea tarda, and diagnose and treat the erythropoietic porphyrias, including chronic erythrocyte transfusions, bone marrow or hematopoietic stem cell transplants, and experimental pharmacologic chaperone and stem cell gene therapies for congenital erythropoietic protoporphyria. These developments are reviewed to update hematologists on the latest advances in these diverse disorders.

  14. The porphyrias: advances in diagnosis and treatment.

    PubMed

    Balwani, Manisha; Desnick, Robert J

    2012-01-01

    The inborn errors of heme biosynthesis, the porphyrias, are 8 genetically distinct metabolic disorders that can be classified as "acute hepatic," "hepatic cutaneous," and "erythropoietic cutaneous" diseases. Recent advances in understanding their pathogenesis and molecular genetic heterogeneity have led to improved diagnosis and treatment. These advances include DNA-based diagnoses for all the porphyrias, new understanding of the pathogenesis of the acute hepatic porphyrias, identification of the iron overload-induced inhibitor of hepatic uroporphyrin decarboxylase activity that causes the most common porphyria, porphyria cutanea tarda, the identification of an X-linked form of erythropoietic protoporphyria due to gain-of-function mutations in erythroid-specific 5-aminolevulinate synthase (ALAS2), and new and experimental treatments for the erythropoietic prophyrias. Knowledge of these advances is relevant for hematologists because they administer the hematin infusions to treat the acute attacks in patients with the acute hepatic porphyrias, perform the chronic phlebotomies to reduce the iron overload and clear the dermatologic lesions in porphyria cutanea tarda, and diagnose and treat the erythropoietic porphyrias, including chronic erythrocyte transfusions, bone marrow or hematopoietic stem cell transplants, and experimental pharmacologic chaperone and stem cell gene therapies for congenital erythropoietic protoporphyria. These developments are reviewed to update hematologists on the latest advances in these diverse disorders.

  15. Vismodegib in the treatment of advanced BCC.

    PubMed

    O'Kane, G M; Lyons, T; McDonald, I; Mulligan, N; Moloney, F J; Murray, D; Kelly, C M

    2014-01-01

    Basal-cell carcinoma (BCC) is the most commonly diagnosed malignancy, comprising over 80 per thousand of non-melanoma skin cancers. Surgical excision is adequate treatment for most BCC's. Options are however limited for the minority of patients presenting with locally advanced inoperable or metastatic BCC. The Hedgehog signalling pathway is a critical driver in the pathogenesis of both sporadic and hereditary BCC. On 31st January 2012, based on a phase II clinical trial the US Food and Drug Administration approved Vismodegib (Erivedge, Roche) a first-in-class, small-molecule oral Hedgehog-inhibitor for the treatment of locally advanced inoperable and metastatic BCC. We present our experience treating the first Irish patient with this agent.

  16. Fates of chlorinated volatile organic compounds in aerobic biological treatment processes: the effects of aeration and sludge addition.

    PubMed

    Chen, Wei-Hsiang; Yang, Wen-Ben; Yuan, Chung-Shin; Yang, Jun-Chen; Zhao, Qing-Liang

    2014-05-01

    The emission of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) is becoming an environmental issue of increasing concern. As biological treatment has been considered as one important approach for VOC removal, lab-scale batch experiments were conducted in this study to investigate the fates of four chlorinated hydrocarbons, including chloroform, carbon tetrachloride, trichloroethylene (TCE), and tetrachloroethylene (PERC), in the biological treatment processes with respect to the effects of aeration and sludge addition. The VOC concentrations in the phases of air, water, and sludge under four simulated treatment stages (the first sedimentation, the forepart and rear part of aerobic biological treatment, and the second sedimentation) were analyzed. The results were used to understand the three-phase partitioning of these compounds and to estimate their potentials for volatilization and biological sorption and degradation in these technologies with the concept of fugacity. It was observed that the VOCs were mainly present in the water phase through the experiments. The effects of aeration or sludge addition on the fates of these VOCs occurred but appeared to be relatively limited. The concentration distributions of the VOCs were well below the reported partitioning coefficients. It was suggested that these compounds were unsaturated in the air and sludge phases, enhancing their potentials for volatilization and biological sorption/degradation through the processes. However, the properties of these chlorinated VOCs such as the volatility, polarity, or even biodegradability caused by their structural characteristics (e.g., the number of chlorine, saturated or unsaturated) may represent more significant factors for their fates in the aerobic biological treatment processes. These findings prove the complication behind the current knowledge of VOC pollutions in WWTPs and are of help to manage the adverse impacts on the environment and public

  17. An integrated approach for monitoring efficiency and investments of activated sludge-based wastewater treatment plants at large spatial scale.

    PubMed

    De Gisi, Sabino; Sabia, Gianpaolo; Casella, Patrizia; Farina, Roberto

    2015-08-01

    WISE, the Water Information System for Europe, is the web-portal of the European Commission (EU) that disseminates the quality state of the receiving water bodies and the efficiency of the municipal wastewater treatment plants (WWTPs) in order to monitor advances in the application of both the Water Framework Directive (WFD) as well as the Urban Wastewater Treatment Directive (UWWTD). With the intention to develop WISE applications, the aim of the work was to define and apply an integrated approach capable of monitoring the efficiency and investments of activated sludge-based WWTPs located in a large spatial area, providing the following outcomes useful to the decision-makers: (i) the identification of critical facilities and their critical processes by means of a Performance Assessment System (PAS), (ii) the choice of the most suitable upgrading actions, through a scenario analysis. (iii) the assessment of the investment costs to upgrade the critical WWTPs and (iv) the prioritization of the critical facilities by means of a multi-criteria approach which includes the stakeholders involvement, along with the integration of some technical, environmental, economic and health aspects. The implementation of the proposed approach to a high number of municipal WWTPs highlighted how the PAS developed was able to identify critical processes with a particular effectiveness in identifying the critical nutrient removal ones. In addition, a simplified approach that considers the cost related to a basic-configuration and those for the WWTP integration, allowed to link the critical processes identified and the investment costs. Finally, the questionnaire for the acquisition of data such as that provided by the Italian Institute of Statistics, the PAS defined and the database on the costs, if properly adapted, may allow for the extension of the integrated approach on an EU-scale by providing useful information to water utilities as well as institutions.

  18. Advanced treatment for basal cell carcinomas.

    PubMed

    Atwood, Scott X; Whitson, Ramon J; Oro, Anthony E

    2014-07-01

    Basal cell carcinomas (BCCs) are very common epithelial cancers that depend on the Hedgehog pathway for tumor growth. Traditional therapies such as surgical excision are effective for most patients with sporadic BCC; however, better treatment options are needed for cosmetically sensitive or advanced and metastatic BCC. The first approved Hedgehog antagonist targeting the membrane receptor Smoothened, vismodegib, shows remarkable effectiveness on both syndromic and nonsyndromic BCCs. However, drug-resistant tumors frequently develop, illustrating the need for the development of next-generation Hedgehog antagonists targeting pathway components downstream from Smoothened. In this article, we will summarize available BCC treatment options and discuss the development of next-generation antagonists.

  19. Advanced Treatment for Basal Cell Carcinomas

    PubMed Central

    Atwood, Scott X.; Whitson, Ramon J.; Oro, Anthony E.

    2014-01-01

    Basal cell carcinomas (BCCs) are very common epithelial cancers that depend on the Hedgehog pathway for tumor growth. Traditional therapies such as surgical excision are effective for most patients with sporadic BCC; however, better treatment options are needed for cosmetically sensitive or advanced and metastatic BCC. The first approved Hedgehog antagonist targeting the membrane receptor Smoothened, vismodegib, shows remarkable effectiveness on both syndromic and nonsyndromic BCCs. However, drug-resistant tumors frequently develop, illustrating the need for the development of next-generation Hedgehog antagonists targeting pathway components downstream from Smoothened. In this article, we will summarize available BCC treatment options and discuss the development of next-generation antagonists. PMID:24985127

  20. Towards better environmental performance of wastewater sludge treatment using endpoint approach in LCA methodology.

    PubMed

    Alyaseri, Isam; Zhou, Jianpeng

    2017-03-01

    The aim of this study is to use the life cycle assessment method to measure the environmental performance of the sludge incineration process in a wastewater treatment plant and to propose an alternative that can reduce the environmental impact. To show the damages caused by the treatment processes, the study aimed to use an endpoint approach in evaluating impacts on human health, ecosystem quality, and resources due to the processes. A case study was taken at Bissell Point Wastewater Treatment Plant in Saint Louis, Missouri, U.S. The plant-specific data along with literature data from technical publications were used to build an inventory, and then analyzed the environmental burdens from sludge handling unit in the year 2011. The impact assessment method chosen was ReCipe 2008. The existing scenario (dewatering-multiple hearth incineration-ash to landfill) was evaluated and three alternative scenarios (fluid bed incineration and anaerobic digestion with and without land application) with energy recovery from heat or biogas were proposed and analyzed to find the one with the least environmental impact. The existing scenario shows that the most significant impacts are related to depletion in resources and damage to human health. These impacts mainly came from the operation phase (electricity and fuel consumption and emissions related to combustion). Alternatives showed better performance than the existing scenario. Using ReCipe endpoint methodology, and among the three alternatives tested, the anaerobic digestion had the best overall environmental performance. It is recommended to convert to fluid bed incineration if the concerns were more about human health or to anaerobic digestion if the concerns were more about depletion in resources. The endpoint approach may simplify the outcomes of this study as follows: if the plant is converted to fluid bed incineration, it could prevent an average of 43.2 DALYs in human life, save 0.059 species in the area from extinction

  1. Limitation of sludge biotic index application for control of a wastewater treatment plant working with shock organic and ammonium loadings.

    PubMed

    Drzewicki, Adam; Kulikowska, Dorota

    2011-11-01

    This study aimed to determine the relationship between activated sludge microfauna, the sludge biotic index (SBI) and the effluent quality of a full-scale municipal wastewater treatment plant (WWTP) working with shock organic and ammonium loadings caused by periodic wastewater delivery from septic tanks. Irrespective of high/low effluent quality in terms of COD, BOD5, ammonium and suspended solids, high SBI values (8-10), which correspond to the first quality class of sludge, were observed. High SBI values were connected with abundant taxonomic composition and the domination of crawling ciliates with shelled amoebae and attached ciliates. High SBI values, even at a low effluent quality, limit the usefulness of the index for monitoring the status of an activated sludge system and the effluent quality in municipal WWTP-treated wastewater from septic tanks. It was shown that a more sensitive indicator of effluent quality was a change in the abundance of attached ciliates with a narrow peristome (Vorticella infusionum and Opercularia coarctata), small flagellates and crawling ciliates (Acineria uncinata) feeding on flagellates.

  2. The survival of Escherichia coli, faecal coliforms and enterobacteriaceae in general in soil treated with sludge from wastewater treatment plants.

    PubMed

    Estrada, I B; Aller, A; Aller, F; Gómez, X; Morán, A

    2004-06-01

    We monitored the effect of the application of treated sludge on the behaviour of enterobacteriaceae (mainly faecal coliforms and especially Escherichia coli) in the soil, and studied their evolution over time after application. Three different sludges were used: two from a municipal sewage plant, one of them had been subjected to anaerobic digestion and heat drying, and the other to anaerobic digestion and mechanical dehydration, and one from a dairy waste treatment to aerobic digestion and gravity thickening. Two types of tests were carried out: type O, in the open air, with no possibility of controlling humidity or temperature; and type L, under laboratory conditions, with controlled temperature and humidity. Sludge tests were also run on unscreened soil previously treated with chemical fertilizer. After 80 days of experimentation the populations of faecal coliforms and E. coli had decreased considerably or were undetectable in assays carried out on the soil/sludge mixtures, under both open-air and laboratory conditions, but that, over the same period, in the mixtures containing chemical fertilizer (calcium ammonium nitrate) there had been a considerable increase in the micro-organism populations studied.

  3. Association of naturally occurring radionuclides in sludges from Drinking Water Treatment Plants previously optimized for their removal.

    PubMed

    Baeza, A; Salas, A; Guillén, J; Muñoz-Serrano, A

    2014-02-01

    The raw water used in Drinking Water Treatment Plants (DWTPs) can present high values of naturally occurring radionuclides. In order to reduce this content, the routine working conditions of DWTPs were successfully modified. This meant that those radionuclides were accumulated in the sludges generated, whose radioactive content was frequently above the exemption levels. It therefore becomes necessary to assess the association of naturally occurring radionuclides in the sludges for their potential use as agricultural fertilizers. Two approaches were studied: (a) the effect of different sequential extraction methods applied to a selected sludge; and (b) the effect of the different contents of inorganic complexes dissolved in the input water on the composition of the sludges generated by two DWTPs with different origins of their input water. Uranium and radium were mainly associated with the carbonated and reducible fractions, while (210)Po and (228)Th were associated with the residual fraction. There were differences between the two speciation methods, but the order of bioavailable radionuclides was roughly the same: (226)Ra≈(234,238)U>(228)Th>(210)Po. The major inorganic complexes content, mainly carbonate, in the raw water affected the radionuclide association. The greater the carbonate content in the raw water, the greater was the association of uranium and radium with the carbonated and easily reducible fractions.

  4. Delisting petition for 300-M saltstone (treated F006 sludge) from the 300-M liquid effluent treatment facility

    SciTech Connect

    Not Available

    1989-04-04

    This petition seeks exclusion for stabilized and solidified sludge material generated by treatment of wastewater from the 300-M aluminum forming and metal finishing processes. The waste contains both hazardous and radioactive components and is classified as a mixed waste. The objective of this petition is to demonstrate that the stabilized sludge material (saltstone), when properly disposed, will not exceed the health-based standards for the hazardous constituents. This petition contains sampling and analytical data which justify the request for exclusion. The results show that when the data are applied to the EPA Vertical and Horizontal Spread (VHS) Model, health-based standards for all hazardous waste constituents will not be exceeded during worst case operating and environmental conditions. Disposal of the stabilized sludge material in concrete vaults will meet the requirements pertaining to Waste Management Activities for Groundwater Protection at the Savannah River Site in Aiken, S.C. Documents set forth performance objectives and disposal options for low-level radioactive waste disposal. Concrete vaults specified for disposal of 300-M saltstone (treated F006 sludge) assure that these performance objectives will be met.

  5. Additional treatment of wastewater reduces endocrine disruption in wild fish--a comparative study of tertiary and advanced treatments.

    PubMed

    Baynes, Alice; Green, Christopher; Nicol, Elizabeth; Beresford, Nicola; Kanda, Rakesh; Henshaw, Alan; Churchley, John; Jobling, Susan

    2012-05-15

    Steroid estrogens are thought to be the major cause of feminization (intersex) in wild fish. Widely used wastewater treatment technologies are not effective at removing these contaminants to concentrations thought to be required to protect aquatic wildlife. A number of advanced treatment processes have been proposed to reduce the concentrations of estrogens entering the environment. Before investment is made in such processes, it is imperative that we compare their efficacy in terms of removal of steroid estrogens and their feminizing effects with other treatment options. This study assessed both steroid removal and intersex induction in adult and early life stage fish (roach, Rutilus rutilus). Roach were exposed directly to either secondary (activated sludge process (ASP)), tertiary (sand filtrated (SF)), or advanced (chlorine dioxide (ClO(2)), granular activated charcoal (GAC)) treated effluents for six months. Surprisingly, both the advanced GAC and tertiary SF treatments (but not the ClO(2) treatment) significantly removed the intersex induction associated with the ASP effluent; this was not predicted by the steroid estrogen measurements, which were higher in the tertiary SF than either the GAC or the ClO(2). Therefore our study highlights the importance of using both biological and chemical analysis when assessing new treatment technologies.

  6. Heavy metal removal from sewage sludge ash by thermochemical treatment with gaseous hydrochloric acid.

    PubMed

    Vogel, Christian; Adam, Christian

    2011-09-01

    Sewage sludge ash (SSA) is a suitable raw material for fertilizers due to its high phosphorus (P) content. However, heavy metals must be removed before agricultural application and P should be transferred into a bioavailable form. The utilization of gaseous hydrochloric acid for thermochemical heavy metal removal from SSA at approximately 1000 °C was investigated and compared to the utilization of alkaline earth metal chlorides. The heavy metal removal efficiency increased as expected with higher gas concentration, longer retention time and higher temperature. Equivalent heavy metal removal efficiency were achieved with these different Cl-donors under comparable conditions (150 g Cl/kg SSA, 1000 °C). In contrast, the bioavailability of the P-bearing compounds present in the SSA after thermal treatment with gaseous HCl was not as good as the bioavailability of the P-bearing compounds formed by the utilization of magnesium chloride. This disadvantage was overcome by mixing MgCO(3) as an Mg-donor to the SSA before thermochemical treatment with the gaseous Cl-donor. A test series under systematic variation of the operational parameters showed that copper removal is more depending on the retention time than the removal of zinc. Zn-removal was declined by a decreasing ratio of the partial pressures of ZnCl(2) and water.

  7. Microalgae-activated sludge treatment of molasses wastewater in sequencing batch photo-bioreactor.

    PubMed

    Tsioptsias, Costas; Lionta, Gesthimani; Samaras, Petros

    2016-08-09

    The aim of this work was the examination of the treatment potential of molasses wastewater, by the utilization of activated sludge and microalgae. The systems used included a sequencing batch bioreactor and a similar photo-bioreactor, favoring microalgae growth. The microalgae treatment of molasses wastewater mixture resulted in a considerable reduction in the total nitrogen content. A reduction in the ammonium and nitrate content was observed in the photo-bioreactor, while the effluent's total nitrogen consisted mainly of 50% organic nitrogen. The transformation of the nitrogen forms in the photo-bioreactor was attributed to microalgae activity, resulting in the production of a better quality effluent. Lower COD removal was observed for the photo-bioreactor than the control, which however increased, by the replacement of the anoxic phase by a long aeration period. The mechanism of nitrogen removal included both the denitrification process during the anoxic stage and the microalgae activities, as the replacement of the anoxic stage resulted in low total nitrogen removal capacities. A decrease in the photobioreactor performance was observed after 35 days of operation due to biofilm formation on the light tube surface, while the operation at higher temperature accelerated microalgae growth, resulting thus in the early failure of the photoreactor.

  8. Assessment of activated sludge, membrane bioreactors and vertical flow wetlands for upgrading sewage treatment works.

    PubMed

    Besançon, A; Le Corre, K S; Dotro, G; Jefferson, B

    2017-01-01

    This paper demonstrates that utilising a vertical flow (VF) wetland after a conventional activated sludge (CAS) delivers equivalent or better effluent quality to a membrane bioreactor (MBR) based on a side-by-side pilot trial. The CAS was operated under the solids retention times (SRT) of 6, 12, and 20 days, with the effluent from each pilot plant fed onto a soil aquifer treatment column to better understand their water reuse application potential. Results showed an upgraded CAS + VF system could deliver effluents with median values of 34 mgO2.L((-1)), 7 mg.L(-1) and 1.9 mg.L(-1) for organics, solids and ammonia nitrogen, respectively, which were statistically similar to those from the MBR. Water reuse standards were achieved by the upgraded system for most parameters, with the exception of total coliform removal. The upgraded system delivered superior metal removal when compared to the CAS. An economic analysis showed upgrading a CAS with a VF wetland was more favourable than investing in an MBR system for example works of 5000 and 50,000 population equivalents if the VF system was operated at hydraulic loading rates of 0.03 m.d(-1) and 0.08 m.d(-1), respectively. This was delivered for a tenth of the carbon footprint of the MBR treatment.

  9. Development of an ATP measurement method suitable for xenobiotic treatment activated sludge biomass.

    PubMed

    Nguyen, Lan Huong; Chong, Nyuk-Min

    2015-09-01

    Activated sludge consumes a large amount of energy to degrade a xenobiotic organic compound. By tracking the energy inventory of activated sludge biomass during the sludge's degradation of a xenobiotic, any disadvantageous effect on the sludge's performance caused by energy deficiency can be observed. The purpose of this study was to develop a reliable and accurate method for measuring the ATP contents of activated sludge cells that were to degrade a xenobiotic organic. Cell disruption and cellular ATP extraction were performed by a protocol with which xenobiotic degrading activated sludge biomass was washed with SDS, treated by Tris and TCA, and followed by bead blasting. The suspension of disrupted cells was filtered before the filtrate was injected into HPLC that was set at optimal conditions to measure the ATP concentration therein. This extraction protocol and HPLC measurement of ATP was evaluated for its linearity, limits of detection, and reproducibility. Evaluation test results reported a R(2) of 0.999 of linear fit of ATP concentration versus activated sludge concentration, a LOD=0.00045mg/L, a LOQ=0.0015mg/L for HPLC measurement of ATP, a MDL=0.46mg/g SS for ATP extraction protocol, and a recovery efficiency of 96.4±2%. This method of ATP measurement was simple, rapid, reliable, and was unburdened of some limitations other methods may have.

  10. Agricultural recycling of treatment-plant sludge: a case study for a vegetable-processing factory.

    PubMed

    Dolgen, Deniz; Alpaslan, M Necdet; Delen, Nafiz

    2007-08-01

    The present study evaluated the possibility of using the sludge produced by a vegetable-processing factory in agriculture. The sludge was amended with a soil mixture (i.e., a mixture of sand, soil, and manure) and was applied at 0, 165, 330, 495 and 660 t/ha to promote the growth of cucumbers. The effects of various sludge loadings on plant growth were assessed by counting plants and leaves, measuring stem lengths, and weighing the green parts and roots of the plants. We also compared heavy metal uptake by the plants for sludge loadings of 330, 495, and 660 t/ha with various recommended standards for vegetables. Our results showed that plant growth patterns were influenced to some extent by the sludge loadings. In general, the number of leaves, stem length, and dry weight of green parts exhibited a pronounced positive growth response compared with an unfertilized control, and root growth showed a lesser but still significant response at sludge loadings of 165 and 330 t/ha. The sludge application caused no significant increase in heavy metal concentrations in the leaves, though zinc (Zn) and iron (Fe) were found at elevated concentrations. However, despite the Zn and Fe accumulation, we observed no toxicity symptoms in the plants. This may be a result of cucumber's tolerance of high metal levels.

  11. GC/MS analysis of triclosan and its degradation by-products in wastewater and sludge samples from different treatments.

    PubMed

    Tohidi, Fatemeh; Cai, Zongwei

    2015-08-01

    A gas chromatography/mass spectrometry (GC/MS)-based method was developed for simultaneous determination of triclosan (TCS) and its degradation products including 2,4-dichlorophenol (2,4-DCP), 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD), and methyl triclosan (MTCS) in wastewater and sludge samples. The method provides satisfactory detection limit, accuracy, precision and recovery especially for samples with complicated matrix such as sewage sludge. Liquid-liquid extraction and accelerated solvent extraction (ASE) methods were applied for the extraction, and column chromatography was employed for the sample cleanup. Analysis was performed by GC/MS in the selected ion monitoring (SIM) mode. The method was successfully applied to wastewater and sludge samples from three different municipal wastewater treatment plants (WWTPs). Satisfactory mean recoveries were obtained as 91(±4)-106(±7)%, 82(±3)-87(±4)%, 86(±6)-87(±8)%, and 88(±4)-105(±3)% in wastewater and 88(±5)-96(±8)%, 84(±2)-87(±3)%, 84(±7)-89(±4)%, and 88(±3)-97(±5)% in sludge samples for TCS, 2,4-DCP, 2,8-DCDD, and MTCS, respectively. TCS degradation products were detected based on the type of the wastewater and sludge treatment. 2,8-DCDD was detected in the plant utilizing UV disinfection at the mean level of 20.3(±4.8) ng/L. 2,4-DCP was identified in chemically enhanced primary treatment (CEPT) applying chlorine disinfection at the mean level of 16.8(±4.5) ng/L). Besides, methyl triclosan (MTCS) was detected in the wastewater collected after biological treatment (10.7 ± 3.3 ng/L) as well as in sludge samples that have undergone aerobic digestion at the mean level of 129.3(±17.2) ng/g dry weight (dw).

  12. Synergistic effect of rice husk addition on hydrothermal treatment of sewage sludge: fate and environmental risk of heavy metals.

    PubMed

    Shi, Wansheng; Liu, Chunguang; Shu, Youju; Feng, Chuanping; Lei, Zhongfang; Zhang, Zhenya

    2013-12-01

    Hydrothermal treatment (HTT) at 200°C was applied to immobilize heavy metals (HMs) and the effect of rice husk (RH) addition was investigated based on total HMs concentration, fractionation and leaching tests. The results indicated that a synergistic effect of RH addition and HTT could be achieved on reducing the risk of HMs from medium and low risk to no risk. Metals were redistributed and transformed from weakly bounded state to stable state during the HTT process under RH addition. Notably at a RH/sludge ratio of 1/1.75 (d.w.), all the HMs showed no eco-toxicity and no leaching toxicity, with the concentrations of leachable Cr, Ni, Cu and Cd decreased by 17%, 89%, 95% and 93%, respectively. This synergistic effect of RH addition and HTT on the risk reduction of HMs implies that HTT process with RH addition could be a promising and safe disposal technology for sewage sludge treatment in practice.

  13. New advances in targeted gastric cancer treatment

    PubMed Central

    Lazăr, Daniela Cornelia; Tăban, Sorina; Cornianu, Marioara; Faur, Alexandra; Goldiş, Adrian

    2016-01-01

    Despite a decrease in incidence over past decades, gastric cancer remains a major global health problem. In the more recent period, survival has shown only minor improvement, despite significant advances in diagnostic techniques, surgical and chemotherapeutic approaches, the development of novel therapeutic agents and treatment by multidisciplinary teams. Because multiple genetic mutations, epigenetic alterations, and aberrant molecular signalling pathways are involved in the development of gastric cancers, recent research has attempted to determine the molecular heterogeneity responsible for the processes of carcinogenesis, spread and metastasis. Currently, some novel agents targeting a part of these dysfunctional molecular signalling pathways have already been integrated into the standard treatment of gastric cancer, whereas others remain in phases of investigation within clinical trials. It is essential to identify the unique molecular patterns of tumours and specific biomarkers to develop treatments targeted to the individual tumour behaviour. This review analyses the global impact of gastric cancer, as well as the role of Helicobacter pylori infection and the efficacy of bacterial eradication in preventing gastric cancer development. Furthermore, the paper discusses the currently available targeted treatments and future directions of research using promising novel classes of molecular agents for advanced tumours. PMID:27570417

  14. Decolouration of H2SO4 leachate from phosphorus-saturated alum sludge using H2O2 and advanced oxidation processes in phosphorus recovery strategy.

    PubMed

    Zhao, X H; Zhao, Y Q

    2009-12-01

    As a part of attempt for phosphorus (P) recovery from P-saturated alum sludge, which was used as a low-cost P-adsorbent in treatment reed bed for wastewater treatment, decolouration of H(2)SO(4) leachate obtained from previous experiment, possessing a great deal of P, aluminum and red-brown coloured materials (RBCMs), by using H(2)O(2) and advanced oxidation processes (AOPs) was investigated. The use of H(2)O(2) and AOPs in the forms of Fenton (H(2)O(2)/Fe(2 +)) and photo-Fenton (UV/H(2)O(2)/Fe(2 +)) were tested. The changes in colour and total organic carbon (TOC) were taken place as a result of mineralization of RBCMs. The results revealed that all of these three processes examined were efficient. It was found that about 98% colour and 47% TOC can be removed under photo-Fenton treatment after 8 hours of UV irradiation.Correspondingly, the reaction rates of H(2)O(2) and Fenton systems were slow, but 100% colour and 59% TOC removal of H(2)O(2) process and 100% colour and 67% TOC reductions of Fenton process can be achieved after 72 hours of reaction. The changes of structure and molecular weight/size of RBCMs were also evaluated by HPLC and UV-vis spectroscopic analysis. From the results, some chromophores of RBCMs such as aromatic groups were appeared to be easily degraded to the smaller refractory components. Hence, based on the experimental results and considering the investment and expediency of operation, H(2)O(2) and Fenton oxidation could be suitable technologies for the treatment of the RBCMs derived from P-extraction stage by using H(2)SO(4) leaching.

  15. Investigation of nonylphenol and nonylphenol ethoxylates in sewage sludge samples from a metropolitan wastewater treatment plant in Turkey.

    PubMed

    Ömeroğlu, Seçil; Murdoch, Fadime Kara; Sanin, F Dilek

    2015-01-01

    Nonylphenol ethoxylates (NPEOs) have drawn significant attention within the last decade for both scientific and legislative reasons. In Turkey, the Regulation Regarding the Use of Domestic and Urban Sludges on Land states a limit value for the sum of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) as NPE (NPE=NP+NP1EO+NP2EO). Unfortunately a standard method for the determination of these chemicals has not been yet set by the authorities and no data exists about the concentrations of NP and NPEOs in sewage sludge in Turkey. The aim of this study is to propose simple and easily applicable extraction and measurement techniques for 4-n-nonylphenol (4-n-NP), NP, NP1EO and NP2EO in sewage sludge samples and investigate the year round concentrations in a Metropolitan Wastewater Treatment Plant (WWTP) in Turkey. Different extraction techniques and GC/MS methods for sewage sludge were tested. The best extraction method for these compounds was found to be ultrasonication (5 min) using acetone as the solvent with acceptable recovery of analytes suggested by USEPA and other studies. The optimized extraction method showed good repeatability with relative standard deviations (RSDs) less than 6%. The recovery of analytes were within acceptable limits suggested by USEPA and other studies. The limits of detection (LODs) were 6 µg kg(-1) for NP and NP1EO, 12 µg kg(-1) for NP2EO and 0.03 µg kg(-1) for 4-n-NP. The developed method was applied to sewage sludge samples obtained from the Central WWTP in Ankara, Turkey. The sum NPE (NP+NP1EO+NP2EO) was found to be in between 5.5 µg kg(-1) and 19.5 µg kg(-1), values which are in compliance with Turkish and European regulations.

  16. Possible Applications of Hardening Slurries with Fly Ash from Thermal Treatment of Municipal Sewage Sludge in Environmental Protection Structures

    NASA Astrophysics Data System (ADS)

    Falacinski, Paweł; Szarek, Łukasz

    2016-06-01

    In Poland, in recent years, there has been a rapid accumulation of sewage sludge - a by-product in the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. The more stringent regulations and strategic goals adopted for modern sewage management have necessitated the application of modern engineering methodology for the disposal of sewage sludge. One approach is incineration. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. Hence, intensive work is in progress for environmentally safe management of this type of waste. The aim of the experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. This type of hardening slurry with various types of additives, e.g. coal combustion products, is used in the construction of cut-off walls in hydraulic structures. The article presents the technological and functional parameters of hardening slurries with an addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analysed on the basis of their basic properties, i.e. density, contractual viscosity, water separation, structural strength, volumetric density, hydraulic conductivity, compressive and tensile strength. The mandated requirements for slurries employed in the construction of cut-off walls in flood embankments are listed as a usefulness criteria. The article presents the potential uses of fly ash from SSTT in hardening slurry technology. It also suggests directions for further research to fully identify other potential uses of this by-product in this field.

  17. Therapeutic advances in the treatment of vasculitis.

    PubMed

    Eleftheriou, Despina; Brogan, Paul A

    2016-04-26

    Considerable therapeutic advances for the treatment of vasculitis of the young have been made in the past 10 years, including the development of outcome measures that facilitate clinical trial design. Notably, these include: a recognition that some patients with Kawasaki Disease require corticosteroids as primary treatment combined with IVIG; implementation of rare disease trial design for polyarteritis nodosa to deliver the first randomised controlled trial for children; first clinical trials involving children for anti-neutrophil cytoplasmic antibody (ANCA) vasculitis; and identification of monogenic forms of vasculitis that provide an understanding of pathogenesis, thus facilitating more targeted treatment. Robust randomised controlled trials for Henoch Schönlein Purpura nephritis and Takayasu arteritis are needed; there is also an over-arching need for trials examining new agents that facilitate corticosteroid sparing, of particular importance in the paediatric population since glucocorticoid toxicity is a major concern.

  18. Preparation and characterization of ceramic products by thermal treatment of sewage sludge ashes mixed with different additives.

    PubMed

    Merino, Ignacio; Arévalo, Luis F; Romero, Fernando

    2007-01-01

    The study of the ceramic characteristics of sludge ashes, alone or mixed with additives (kaolin, montmorillonite, illitic clay, powdered flat glass) includes characterization of additives, preparation of probes (dry or wet mixed), thermal treatment (up to 1200 degrees C, except melting or deformation) and control (densities, compressive strengths and water absorption). Thermal treatment increases the density and compressive strength of probes (both parameters go through maxima, with later decreases) and decreases the absorption of water. The densification is also revealed by the evolution of the ratio of decrease of volume/loss of mass. The maximum values of compressive strengths were obtained for 25% of illitic clay, montmorillonite and glass powder. Densification concerning probes with sludge ashes alone does not occur with kaolin. Experimental data were adjusted to exponential relationships between compressive strengths and densities for every composition, and also to a general equation for all probes. The apparent density obtained was adjusted to a non-linear dependence with temperature, leading to a maximum in density and permitting calculating the temperature of occurrence of this maximum. The adjustment was not possible for probes containing kaolin, requiring presumably higher temperatures to densify. Water absorption has low values for ashes or kaolin probes, intermediate values for illite and powdered flat glass probes and high values for montmorillonite probes. Excepting with kaolin, ceramic materials with better characteristics than sludge ashes without additives were obtained at lower treatment temperatures.

  19. Optimization of Fenton oxidation pre-treatment for B. thuringiensis - based production of value added products from wastewater sludge.

    PubMed

    Pham, T T H; Brar, S K; Tyagi, R D; Surampalli, R Y

    2010-08-01

    Fenton oxidation pretreatment was investigated for enhancement of biodegradability of wastewater sludge (WWS) which was subsequently used as substrate for the production of value- added products. The Response surface method with fractional factorial and central composite designs was applied to determine the effects of Fenton parameters on solubilization and biodegradability of sludge and the optimization of the Fenton process. Maximum solubilization and biodegradability were obtained as 70% and 74%, respectively at the optimal conditions: 0.01 ml H(2)O(2)/g SS, 150 [H(2)O(2)](0)/[Fe(2+)](0), 25 g/L TS, at 25 degrees C and 60 min duration. Further, these optimal conditions were tested for the production of a value added product, Bacillus thuringiensis (Bt) which is being used as a biopesticide in the agriculture and forestry sector. It was observed that Bt growth using Fenton oxidized sludge as a substrate was improved with a maximum total cell count of 1.63 x 10(9)CFU ml(-1) and 96% sporulation after 48 h of fermentation. The results were also tested against ultrasonication treatment and the total cell count was found to be 4.08 x 10(8)CFU ml(-1) with a sporulation of 90%. Hence, classic Fenton oxidation was demonstrated to be a rather more promising chemical pre-treatment for Bt - based biopesticide production using WWS when compared to ultrasonication as a physical pre-treatment.

  20. Genetic Discoveries and Treatment Advances in Neuroblastoma

    PubMed Central

    Bagatell, Rochelle; Cohn, Susan L.

    2016-01-01

    Purpose of review Major advances in our understanding of the genetic basis of neuroblastoma and the role somatic alterations play in driving tumor growth have led to improvements in risk-stratified therapy and have provided the rationale for targeted therapies. In this review, we highlight current risk-based treatment approaches and discuss the opportunities and challenges of translating recent genomic discoveries into the clinic. Recent Findings Significant progress in the treatment of neuroblastoma has been realized using risk-based treatment strategies. Outcome has improved for all patients, including those classified as high-risk, although survival remains poor for this cohort. Integration of whole-genome DNA copy number and comprehensive molecular profiles into neuroblastoma classification systems will allow more precise prognostication and refined treatment assignment. Promising treatments that include targeted systemic radiotherapy, pathway-targeted small molecules, and therapy targeted at cell surface molecules are being evaluated in clinical trials, and recent genomic discoveries in relapsed tumor samples have led to the identification of new actionable mutations. Summary The integration of refined treatment stratification based on whole-genome profiles with therapeutics that target the molecular drivers of malignant behavior in neuroblastoma has the potential to dramatically improve survival with decreased toxicity. PMID:26576010

  1. Effects of dried wastewater-treatment sludge application on ground-water quality in South Dade County, Florida

    USGS Publications Warehouse

    Howie, Barbara

    1992-01-01

    Four test fields in the south Dade agricultural area were studied to determine the effects of sludge application on ground-water quality. Two fields had been cultivated for 10 years or more, and two had not been farmed for at least 10 years. The fields were representative of the area's two soil types (Rockdale and Perrine marl) and two major crop types (row crops and groves). Before the application of sludge, wells upgradient of, within, and downgradient of each field were sampled for possible sludge contaminants at the end of wet and dry seasons. Municipal wastewater treatment sludge from the Dade County Water and Sewe Authority Department was then applied to the fields at varying application rates. The wells at each field were sampled over a 2-year period under different hydrologic conditions for possible sludge-related constituents (specific conductance, pH, alkalinity, nitrogen, phosphorus, total organic carbon, copper, iron, magnesium, manganese, potassium, zinc, arsenic, cadmium, chloride, chromium, lead, mercury, nickel, and sodium). Comparisons were made between water quality in the vicinity of the test fields and Florida Department of Environmental Regulation primary and secondary drinking-water regulations, an between water quality upgradient of, beneath, and downgradient of the fields. Comparisons between presludge and postsludge water quality did not indicate any improvement because of retention of agrichemicals by the sludge nor did they indicate any deterioration because of leaching from the sludge. Comparisons of water quality upgradient of the fields to water quality beneath and downgradient of the fields also did not indicate any changes related to sludge. Florida Department of Environmental Regulation primary and secondary drinking-water regulations wer exceeded at the Rockdale maximum-application field by mercury (9.5 ug/L (micrograms per liter)), and the Perrine marl maximum-application field by manganese (60 ug/L) and lead (85 ug/L), and at the

  2. Effect of earthworms on the performance and microbial communities of excess sludge treatment process in vermifilter.

    PubMed

    Liu, Jing; Lu, Zhibo; Yang, Jian; Xing, Meiyan; Yu, Fen; Guo, Meiting

    2012-08-01

    Previous studies have shown that the stabilization of excess sludge by vermifiltration can be improved significantly through the use of earthworms. To investigate the effect of earthworms on enhancing sludge stabilization during the vermifiltration process, a vermifilter (VF) with earthworms and a conventional biofilter (BF) without earthworms were compared. The sludge reduction capability of the VF was ∼85% higher than that of the BF. Specifically, elemental analysis indicated that earthworms enhanced the stabilization of organic matter. Furthermore, earthworm predation strongly regulated microbial biomass while improving microbial activity. Denaturing gradient gel electrophoresis (DGGE) analysis showed that the most abundant microbes in the VF biofilms and earthworm casts were Flavobacterium, Myroides, Sphingobacterium, and Myxococcales, all of which are known to be highly effective at degrading organic matter. These results indicate that earthworms can improve the stabilization of excess sludge during vermifiltration, and reveal the processes by which this is achieved.

  3. Occurrence, fate and risk assessment of parabens and their chlorinated derivatives in an advanced wastewater treatment plant.

    PubMed

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

    2015-12-30

    In the present study, parabens, p-hydroxybenzoic acid (PHBA) and chlorinated derivatives, were simultaneously determined in wastewater and sludge samples along the whole process in an advanced wastewater treatment plant (WWTP). Nine target compounds were detected in this WWTP, and methylparaben and PHBA were the dominant compounds in these samples. It is noteworthy that octylparaben with longer chain was firstly detected in this work. Mass balance results showed that 91.8% of the initial parabens mass loading was lost mainly due to degradation, while the contribution of sorption and output of primary and excess sludge was much less (7.5%), indicating that biodegradation played a significant role in the removal of parabens during the conventional treatment process. Specifically, parabens were mainly degraded in the anaerobic tank, and PHBA could be effectively removed at high rates after the advanced treatment. However, both biodegradation and adsorption accounted for minor contribution to the removal of chlorinated parabens during conventional treatment process, and they were only scantly removed by conventional treatment (33.9-40.7%) and partially removed by advanced treatment (59.2-82.8%). Risk assessment indicated that parabens and their chlorinated derivatives in second and tertiary effluent are not likely to produce biological effects on aquatic ecosystems.

  4. Myeloma Today: Disease Definitions and Treatment Advances

    PubMed Central

    Rajkumar, S. Vincent

    2015-01-01

    There have been major advances in the diagnosis, staging, risk-stratification, and management of multiple myeloma (MM). In addition to established CRAB (hypercalcemia, renal failure, anemia, and lytic bone lesions) features, new diagnostic criteria include 3 new biomarkers to diagnose the disease: bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain ratio ≥100, and >1 focal lesion on magnetic resonance imaging. MM can be classified into several subtypes based on baseline cytogenetics, and prognosis varies according to underlying cytogenetic abnormalities. A Revised International Staging System has been developed which combines markers of tumor burden (albumin, beta-2 microglobulin) with markers of aggressive disease biology (high risk cytogenetics and elevated serum lactate dehydrogenase). Although the approach to therapy remains largely the same, the treatment options at every stage of the disease have changed. Carfilzomib, pomalidomide, and panobinostat have been approved for the treatment of the disease. Elotuzumab, daratumumab, and ixazomib are expected to be approved shortly. These drugs combined with older agents such as cyclophosphamide, dexamethasone, thalidomide, bortezomib, and lenalidomide dramatically increase the repertoire of regimens available for the treatment of MM. This review provides a concise overview of recent advances in MM, including updates to diagnostic criteria, staging, risk-stratification, and management. PMID:26565896

  5. A new process for efficiently producing methane from waste activated sludge: alkaline pretreatment of sludge followed by treatment of fermentation liquid in an EGSB reactor.

    PubMed

    Zhang, Dong; Chen, Yinguang; Zhao, Yuxiao; Ye, Zhengxiang

    2011-01-15

    In the literature the production of methane from waste activated sludge (WAS) was usually conducted in a continuous stirred tank reactor (CSTR) after sludge was pretreated. It was reported in our previous publication that compared with other pretreatment methods the methane production in CSTR could be significantly enhanced when sludge was pretreated by NaOH at pH 10 for 8 days. In order to further improve methane production, this study reported a new process for efficiently producing methane from sludge, that is, sludge was fermented at pH 10 for 8 days, which was adjusted by Ca(OH)(2), and then the fermentation liquid was treated in an expanded granular sludge bed (EGSB) for methane generation. First, for comparing the methane production observed in this study with that reported in the literature, the conventional operational model was applied to produce methane from the pH 10 pretreated sludge, that is, directly using the pH 10 pretreated sludge to produce methane in a CSTR. It was observed that the maximal methane production was only 0.61 m(3)CH(4)/m(3)-reactor/day. Then, the use of fermentation liquid of pH 10 pretreated sludge to produce methane in the reactors of up-flow anaerobic sludge bed (UASB), anaerobic sequencing batch reactor (ASBR) and EGSB was compared. The maximal methane production in UASB, ASBR, and EGSB reached 1.41, 3.01, and 12.43 m(3)CH(4)/m(3)-reactor/day, respectively. Finally, the mechanisms for EGSB exhibiting remarkably higher methane production were investigated by enzyme, adenosine-triphosphate (ATP), scanning electron microscope (SEM) and fluorescence in situ hybridization (FISH) analyses. It was found that the granular sludge in EGSB had the highest conversion efficiency of acetic acid to methane, and the greatest activity of hydrolysis and acidification enzymes and general physiology with much more Methanosarcinaceae.

  6. Comparison of bioleaching and electrokinetic remediation processes for removal of heavy metals from wastewater treatment sludge.

    PubMed

    Xu, Ying; Zhang, Chaosheng; Zhao, Meihua; Rong, Hongwei; Zhang, Kefang; Chen, Qiuli

    2017-02-01

    Heavy metals prevent the growing amount of sewage sludge from being disposed as fertilizeron land. The electrokinetic remediation and bioleaching technology are the promising methods to remove heavy metals. In recent years, some innovation has been made to achieve better efficiency, including the innovation of processes and agents. This paper reviews the development of the electrokinetic remediation and bioleaching technology and analyses their advantages and limitation, pointing out the need of the future research for the heavy metals-contaminated sewage sludge.

  7. The contribution of thermophilic anaerobic digestion to the stable operation of wastewater sludge treatment.

    PubMed

    Zábranská, J; Dohányos, M; Jenícek, P; Zaplatílková, P; Kutil, J

    2002-01-01

    Thermophilic anaerobic digestion of sewage sludge has been successfully operated in full-scale tanks almost three years. The higher loading capacity and specific biogas production rate in comparison with mesophilic digestion was proved. Thermophilic anaerobic sludge is also more resistant against foaming problems. Biogas from thermophilic tanks contains less hydrogen sulphide and other malodorous substances. Pathogens removal rate is apparently more efficient in the thermophilic process.

  8. Enhanced volatile fatty acid production from excess sludge by combined free nitrous acid and rhamnolipid treatment.

    PubMed

    Wu, Qing-Lian; Guo, Wan-Qian; Bao, Xian; Zheng, He-Shan; Yin, Ren-Li; Feng, Xiao-Chi; Luo, Hai-Chao; Ren, Nan-Qi

    2017-01-01

    VFA production from excess sludge (ES) was greatly enhanced by a low-cost and high-efficient treatment: 0.67mg/L free nitrous acid (FNA) pretreatment combined with 0.04g/g TSS rhamnolipid (RL) addition (FNA+RL), which significantly shortened fermentation time to 3days and increased VFA production to 352.26mgCOD/g VSS (5.42 times higher than raw ES). Propionic and acetic acids were the two leading components (71.86% of the total VFA). Mechanism investigation manifested FNA+RL improved the biodegradability of ES, achieved positive synergetic effect on solubilization, hydrolysis and acidification efficiencies, and inhibited methanation. Microbial community distribution further explained the above phenomena. The bacteria related to polysaccharides/protein utilization and VFA generation, including Clostridium, Megasphaera and Proteiniborus, were mainly observed in FNA+RL, whereas gas-forming bacteria Anaerolineae and acid-consuming bacteria Proteobacteria were assuredly suppressed. Besides, Propionibacterineae associated with propionic acid generation was exclusively enriched in sole RL and FNA+RL.

  9. Heavy metal removal from sewage sludge ash by thermochemical treatment with polyvinylchloride.

    PubMed

    Vogel, Christian; Exner, Robert M; Adam, Christian

    2013-01-02

    Sewage sludge ash (SSA) is a prospective phosphorus source for the future production of recycling P-fertilizers. Due to its high heavy metals contents and the relatively low P plant-availability, SSA must be treated before agricultural utilisation. In this paper SSA was thermochemically treated with PVC in a bench-scale rotary furnace in order to remove heavy metals via the chloride pathway. PVC has a high Cl-content of 52-53% and a high heating value that can be beneficially used for the thermochemical process. Large amounts of waste PVC are already recovered in recycling processes, but there are still some fractions that would be available for the proposed thermochemical process, for example, the low quality near-infrared(NIR)-fraction from waste separation facilities. Heavy metals were effectively removed at temperatures in the range of 800-950 °C via the gas phase by utilisation of PVC as Cl-donor. The resulting P plant-availability was comparable to SSA thermochemically treated with MgCl(2) as Cl-donor if MgO was used as an additive (Mg-donor). A further increase of the plant availability of phosphorus was achieved by acid post-treatment of the thermochemically treated SSA.

  10. Gordonia malaquae sp. nov., isolated from sludge of a wastewater treatment plant.

    PubMed

    Yassin, A F; Shen, Fo-Ting; Hupfer, H; Arun, A B; Lai, Wei-An; Rekha, P D; Young, Chiu Chung

    2007-05-01

    The taxonomic status of a bacterial isolate from the sludge of a wastewater treatment plant was characterized by using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Gordonia, fatty acids C(16 : 0) and C(18 : 0) (found by pyrolysis gas chromatography) and a dihydrogenated menaquinone with nine isoprene units [MK-9(H2)] as the predominant menaquinone. The genus assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that the novel isolate constitutes a hitherto unknown subline within the genus Gordonia, displaying 95.9 to 97.6 % gene sequence similarity to the recognized species of the genus. The novel isolate was distinguished from the type strains of phylogenetically related species by using a set of phenotypic features. The genotypic and phenotypic data show that the new strain merits classification as a novel species of the genus Gordonia, for which the name Gordonia malaquae sp. nov. is proposed. The type strain is IMMIB WWCC-22(T) (=DSM 45064(T)=CCUG 53555(T)).

  11. Treatment of direct blending dye wastewater and recycling of dye sludge.

    PubMed

    Xu, Xin-Hui; Li, Ming-Li; Yuan, Yuan

    2012-03-06

    A new sorbent material, barium sulfate-Direct Blending Yellow D-3RNL hybrid (BSD), was synthesized and characterized by various methods. Both the anionic dyes, Reactive Brilliant Red X-3B and Weak Acid Green GS were hardly adsorbed by the BSD material, while the sorption of Ethyl Violet (EV) and Victoria Blue B were extremely obvious. The sorption of cationic dyes obeyed the Langmuir isotherm model, which depended on the electric charge attraction. The saturation amount of EV adsorbed onto the BSD material approached to 39.36 mg/g. The sorption of EV changed little with pH from 3 to 12 while it increased with increasing levels of electrolyte. A dye wastewater sampled from Jinjiang Chemicals was treated, and the color removal rate was more than the COD removal rate. In addition, the cationic dye-BSD sludge was utilized as a colorant fill-in coating. The light stability and thermal stability of the colorant was measured and exhibited good features. This work provided a simple and eco-friendly method for dye wastewater treatment with recycling of waste.

  12. Inorganic pigments made from the recycling of coal mine drainage treatment sludge.

    PubMed

    Marcello, R R; Galato, S; Peterson, M; Riella, H G; Bernardin, A M

    2008-09-01

    Continuous industrial development increases energy consumption and, consequently, the consumption of fossil fuels. Coal mineral has been used in Brazil as a solid fuel for thermoelectric generators for several years. However, coal exploitation affects the environment intensely, mainly because Brazilian coal contains excess ash and pyrite (iron disulfide). According to the local coal industry syndicate, the average annual coal run per mine is 6 million ton/year; 3.5 million ton/year are rejected and disposed of in landfills. Besides pyrite, Brazilian coal contains Mn, Fe, Cu, Pb, Zn, Ge, Se, and Co. Additionally, the water used for coal beneficiation causes pyrite oxidation, forming an acid mine drainage (AMD). This drainage solubilizes the metals, transporting them into the environment, making treatment a requirement. This work deals with the use of sedimented residue from treated coal mine drainage sludge to obtain inorganic pigments that could be used in the ceramic industry. The residue was dried, ground and calcined ( approximately 1250 degrees C). The calcined pigment was then micronized (D(50) approximately 2mum). Chemical (XRF), thermal (DTA/TG), particle size (laser), and mineralogical (XRD) analyses were carried out on the residue. After calcination and micronization, mineralogical analyses (XRD) were used to determine the pigment structure at 1250 degrees C. Finally, the pigments were mixed with transparent glaze and fired in a laboratory roller kiln (1130 degrees C, 5min). The results were promising, showing that brown colors can be obtained with pigments made by residues.

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

    PubMed

    Saeedi, Mohsen; Amini, Hamid Reza

    2009-05-01

    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.

  14. A comparative study of clonal selection algorithm for effluent removal forecasting in septic sludge treatment plant.

    PubMed

    Chun, Ting Sie; Malek, M A; Ismail, Amelia Ritahani

    2015-01-01

    The development of effluent removal prediction is crucial in providing a planning tool necessary for the future development and the construction of a septic sludge treatment plant (SSTP), especially in the developing countries. In order to investigate the expected functionality of the required standard, the prediction of the effluent quality, namely biological oxygen demand, chemical oxygen demand and total suspended solid of an SSTP was modelled using an artificial intelligence approach. In this paper, we adopt the clonal selection algorithm (CSA) to set up a prediction model, with a well-established method - namely the least-square support vector machine (LS-SVM) as a baseline model. The test results of the case study showed that the prediction of the CSA-based SSTP model worked well and provided model performance as satisfactory as the LS-SVM model. The CSA approach shows that fewer control and training parameters are required for model simulation as compared with the LS-SVM approach. The ability of a CSA approach in resolving limited data samples, non-linear sample function and multidimensional pattern recognition makes it a powerful tool in modelling the prediction of effluent removals in an SSTP.

  15. Efficacy of an advanced sewage treatment plant in southeast Queensland, Australia, to remove estrogenic chemicals.

    PubMed

    Leusch, Frederic D L; Chapman, Heather F; Korner, Wolfgang; Gooneratne, S Ravi; Tremblay, Louis A

    2005-08-01

    The estrogenicity profile of domestic sewage during treatment at a medium-sized (3800 EP) advanced biological nutrient removal plant in Queensland, Australia, was characterized using a sheep estrogen receptor binding assay (ERBA) and the MCF-7 breast cancer cell proliferation assay (E-Screen). The raw influent was highly estrogenic (20-54 ng/L EEq), and primary treatment resulted in a slight increase in estrogenicity that was detected in one of the assays (6-80 ng/L). Concurrent chemical analysis suggested that most of the estrogenicity in the influent was due to natural hormones (>48%). Secondary activated sludge treatment followed by nitrification/denitrification effectively removed > 95% of the estrogenic activity (to <0.75-2.6 ng/L), and estrogenicity of the final tertiary-treated effluent was below the detection limit of both assays (<0.75 ng/L).

  16. Hydrothermal Liquefaction and Upgrading of Municipal Wastewater Treatment Plant Sludge: A Preliminary Techno-Economic Analysis, Rev.1

    SciTech Connect

    Snowden-Swan, Lesley J.; Zhu, Yunhua; Jones, Susanne B.; Elliott, Douglas C.; Schmidt, Andrew J.; Hallen, Richard T.; Billing, Justin M.; Hart, Todd R.; Fox, Samuel P.; Maupin, Gary D.

    2016-09-01

    A preliminary process model and techno-economic analysis (TEA) was completed for fuel produced from hydrothermal liquefaction (HTL) of sludge waste from a municipal wastewater treatment plant (WWTP) and subsequent biocrude upgrading. The model is adapted from previous work by Jones et al. (2014) for algae HTL, using experimental data generated in fiscal year 2015 (FY15) bench-scale HTL testing of sludge waste streams. Testing was performed on sludge samples received from Metro Vancouver’s Annacis Island WWTP (Vancouver, B.C.) as part of a collaborative project with the Water Environment and Reuse Foundation (WERF). The full set of sludge HTL testing data from this effort will be documented in a separate report to be issued by WERF. This analysis is based on limited testing data and therefore should be considered preliminary. In addition, the testing was conducted with the goal of successful operation, and therefore does not represent an optimized process. Future refinements are necessary to improve the robustness of the model, including a cross-check of modeled biocrude components with the experimental GCMS data and investigation of equipment costs most appropriate at the relatively small scales used here. Environmental sustainability metrics analysis is also needed to understand the broader impact of this technology pathway. The base case scenario for the analysis consists of 10 HTL plants, each processing 100 dry U.S. ton/day (92.4 ton/day on a dry, ash-free basis) of sludge waste and producing 234 barrel per stream day (BPSD) biocrude, feeding into a centralized biocrude upgrading facility that produces 2,020 barrel per standard day of final fuel. This scale was chosen based upon initial wastewater treatment plant data collected by PNNL’s resource assessment team from the EPA’s Clean Watersheds Needs Survey database (EPA 2015a) and a rough estimate of what the potential sludge availability might be within a 100-mile radius. In addition, we received

  17. Advances in HTGR spent fuel treatment technology

    SciTech Connect

    Holder, N.D.; Lessig, W.S.

    1984-08-01

    GA Technologies, Inc. has been investigating the burning of spent reactor graphite under Department of Energy sponsorship since 1969. Several deep fluidized bed burners have been used at the GA pilot plant to develop graphite burning techniques for both spent fuel recovery and volume reduction for waste disposal. Since 1982 this technology has been extended to include more efficient circulating bed burners. This paper includes updates on high-temperature gas-cooled reactor fuel cycle options and current results of spent fuel treatment testing for fluidized and advanced circulating bed burners.

  18. Sludge settling processes in SBR-related sewage treatment plants according to the Biocos method.

    PubMed

    Meusel, S; Englert, R

    2004-01-01

    This paper describes the investigations in a sedimentation and circulation reactor (SU-reactor) of a three-phase Biocos plant. The aim of these investigations was the determination of the temporal and depth-dependent distribution of suspended solid contents, as well as describing the sludge sedimentation curves. The calculated results reveal peculiarities of the Biocos method with regard to sedimentation processes. In the hydraulically uninterrupted (pre-)settling phase, a sludge level depth was observed, which remained constant over the reactor surface and increased linearly according to the sludge volume. The settling and the thickening processes of this phase corresponded to a large extent to the well-known settling test in a one-litre measuring cylinder. During the discharge phase, the investigated settling rate was overlaid by the surface loading rate and the sludge level changed depending on the difference between those two parameters. The solid distribution of the A-phase indicated a formation of functional zones, which were influenced by the surface loading. The formation was comparable to the formation of layers in secondary settling tanks with vertical flow. The concentration equalisation between the biological reactor and the SU-reactor proved to be problematic during the circulation phase, because a type of internal sludge circulation occurred in the SU-reactor. A permanent sludge recirculation seems to be highly recommendable.

  19. Migration of polycyclic aromatic hydrocarbons (PAHs) in urban treatment sludge to the air during PAH removal applications.

    PubMed

    Karaca, Gizem; Cindoruk, S Siddik; Tasdemir, Yücel

    2014-05-01

    In the present study, the amounts of polycylic aromatic hydrocarbons (PAHs) penetrating into air during PAH removal applications from the urban treatment sludge were investigated. The effects of the temperature, photocatalyst type, and dose on the PAH removal efficiencies and PAH evaporation were explained. The sludge samples were taken from an urban wastewater treatment plant located in the city of Bursa, with 585,000 equivalent population. The ultraviolet C (UV-C) light of 254 nm wavelength was used within the UV applications performed on a specially designed setup. Internal air of the setup was vacuumed through polyurethane foam (PUF) columns in order to collect the evaporated PAHs from the sludge during the PAH removal applications. All experiments were performed with three repetitions. The PAH concentrations were measured by gas chromatography-mass spectrometry (GC-MS). It was observed that the amounts of PAHs penetrating into the air were increased with increase of temperature, and more than 80% of PAHs migrated to the air consisted of 3-ring compounds during the UV and UV-diethylamine (DEA) experiments at 38 and 53 degrees C. It was determined that 40% decrease was ensured in sigma12 (total of 12) PAH amounts with UV application and 13% of PAHs in sludge penetrated into the air. In the UV-TiO2 applications, a maximum 80% of sigma12 PAH removal was obtained by adding 0.5% TiO2 of dry weight of sludge. The quantity of PAH penetrating into air did not exceed 15%. UV-TiO2 applications ensured high levels of PAH removal in the sludge and also reduced the quantity of PAH penetrating into the air. Within the scope of the samples added with DEA, there was no increase in PAH removal efficiencies and the penetration of PAHs into air was not decreased. In light of these data, it was concluded that UV-TiO2 application is the most suitable PAH removal alternative that restricts the convection of PAH pollution.

  20. Activated-sludge process: Waste treatment. January 1985-July 1989 (Citations from the Biobusiness data base). Report for January 1985-July 1989

    SciTech Connect

    Not Available

    1989-08-01

    This bibliography contains citations concerning the use of the activated sludge process in waste and waste-water treatment. Biochemistry of the activated sludge process, the effects of various pollutants on process activity, effects of environmental variables such as oxygen and water levels, nutrient requirements of microorganisms employed in activated-sludge processes, and the application of the process to specific wastes such as pharmaceuticals, halocarbons, metallic wastes, dairy wastes, coke-plant waste waters, and petrochemical effluents are among the topics discussed. Operating experiences at large plants are included. (Contains 154 citations fully indexed and including a title list.)

  1. Re-use of drinking water treatment plant (DWTP) sludge: Characterization and technological behaviour of cement mortars with atomized sludge additions

    SciTech Connect

    Husillos Rodriguez, N.; Martinez Ramirez, S.; Blanco Varela, M.T.; Guillem, M.; Puig, J.; Larrotcha, E.; Flores, J.

    2010-05-15

    This paper aims to characterize spray-dried DWTP sludge and evaluate its possible use as an addition for the cement industry. It describes the physical, chemical and micro-structural characterization of the sludge as well as the effect of its addition to Portland cements on the hydration, water demand, setting and mechanical strength of standardized mortars. Spray drying DWTP sludge generates a readily handled powdery material whose particle size is similar to those of Portland cement. The atomized sludge contains 12-14% organic matter (mainly fatty acids), while its main mineral constituents are muscovite, quartz, calcite, dolomite and seraphinite (or clinoclor). Its amorphous material content is 35%. The mortars were made with type CEM I Portland cement mixed with 10 to 30% atomized sludge exhibited lower mechanical strength than the control cement and a decline in slump. Setting was also altered in the blended cements with respect to the control.

  2. A Combined Activated Sludge Anaerobic Digestion Model (CASADM) to understand the role of anaerobic sludge recycling in wastewater treatment plant performance.

    PubMed

    Young, Michelle N; Marcus, Andrew K; Rittmann, Bruce E

    2013-05-01

    The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CASADM example shows that, while effluent COD and N are not changed much by hybrid operation, the hybrid system gives increased methane production in the AD and decreased sludge wasting, both caused mainly by a negative actual solids retention time in the hybrid AD. Increased retention of biomass and EPS allows for more hydrolysis and conversion to methane in the hybrid AD. However, fermenters and methanogens survive in the AS, allowing significant methane production in the settler and thickener of both systems, and AD sludge recycle makes methane formation greater in the hybrid system.

  3. Role of calcium oxide in sludge granulation and methanogenesis for the treatment of palm oil mill effluent using UASB reactor.

    PubMed

    Ahmad, Anwar; Ghufran, Rumana; Abd Wahid, Zularisam

    2011-12-30

    The granulation process in palm oil mill effluent using calcium oxide-cement kiln dust (CaO-CKD) provides an attractive and cost effective treatment option. In this study the efficiency of CaO-CKD at doses of 1.5-20 g/l was tested in batch experiments and found that 10 g of CaO/l caused the greatest degradation of VFA, butyrate and acetate. An upflow anaerobic sludge blanket (UASB) reactor was operated continuously at 35°C for 150 days to investigate the effect of CaO-CKD on sludge granulation and methanogenesis during start-up. The treatment of POME emphasized the influence of varying organic loading rates (OLR). Up to 94.9% of COD was removed when the reactor was fed with the 15.5-65.5 g-CODg/l at an OLR of 4.5-12.5 kg-COD/m(3)d, suggesting the feasibility of using CaO in an UASB process to treat POME. The ratio of volatile solids/total solids (VS/TS) and volatile fatty acids in the anaerobic sludge in the UASB reactor decreased significantly after long-term operation due to the precipitation of calcium carbonate in the granules. Granulation and methanogenesis decreased with an increase in the influent CaO-CKD concentration.

  4. Modified anaerobic digestion elutriated phased treatment for the anaerobic co-digestion of sewage sludge and food wastewater.

    PubMed

    Mo, Kyung; Lee, Wonbae; Kim, Moonil

    2017-02-01

    A modified anaerobic digestion elutriated phased treatment (MADEPT) process was developed for investigating anaerobic co-digestion of sewage sludge and food wastewater. The anaerobic digestion elutriated phased treatment (ADEPT) process is similar to a two-phase system, however, in which the effluent from a methanogenic reactor recycles into an acidogenic reactor to elutriate mainly dissolved organics. Although ADEPT could reduce reactor volume significantly, the unsolubilized solids should be wasted from the system. The MADEPT process combines thermo-alkali solubilization with ADEPT to improve anaerobic performance and to minimize the sludge disposal. It was determined that the optimal volume mixing ratio of sewage sludge and food wastewater was 4 : 1 for the anaerobic co-digestion. The removal efficiencies of total chemical oxygen demand, volatile solids, and volatile suspended solids in the MADEPT process were 73%, 70%, and 64%, respectively. However, those in the ADEPT process were only 48%, 37%, and 40%, respectively, at the same hydraulic retention time (HRT) of 7 days. The gas production of MADEPT was two times higher than that of ADEPT. The thermo-alkali solubilization increased the concentration of dissolved organics so that they could be effectively degraded in a short HRT, implying that MADEPT could improve the performance of ADEPT in anaerobic co-digestion.

  5. Semi-aerobic fermentation as a novel pre-treatment to obtain VFA and increase methane yield from primary sludge.

    PubMed

    Peces, M; Astals, S; Clarke, W P; Jensen, P D

    2016-01-01

    There is a growing trend to consider organic wastes as potential sources of renewable energy and value-add products. Fermentation products have emerged as attractive value-add option due to relative easy production and broad application range. However, pre-fermentation and extraction of soluble products may impact down-stream treatment processes, particularly energy recovery by anaerobic digestion. This paper investigates primary sludge pre-fermentation at different temperatures (20, 37, 55, and 70°C), treatment times (12, 24, 48, and 72h), and oxygen availability (semi-aerobic, anaerobic); and its impact on anaerobic digestion. Pre-fermentation at 20 and 37°C succeeded for VFA production with acetate and propionate being major products. Pre-fermentation at 37, 55, and 70°C resulted in higher solubilisation yield but it reduced sludge methane potential by 20%. Under semi-aerobic conditions, pre-fermentation allowed both VFA recovery (43gCODVFAkg(-1)VS) and improved methane potential. The latter phenomenon was linked to fungi that colonised the sludge top layer during pre-fermentation.

  6. [Advances in the treatment of hypertension].

    PubMed

    Román, O

    1999-04-01

    This review describes the most recent advances in the treatment of essential hypertension, from non pharmacological measures and changes in lifestyles to new blood pressure lowering drugs. A blood pressure lower tha 130/80 mmHg, has been established as the new goal for optimal treatment. In the last two consensus a new range of blood pressure, denominated "high normal" (130-139/85-89 mm Hg) has been incorporated. People with other cardiovascular risk factors and a blood pressure within this range, should be treated. The HOT study recently demonstrated that a reduction to less than 90 mmHg of diastolic pressure is associated with a reduction on cardiovascular morbidity and mortality. The importance of the peak/valley relationship in the election of anti hypertensive medication is also reviewed.

  7. Conditioning of aluminium-based water treatment sludge with Fenton's reagent: effectiveness and optimising study to improve dewaterability.

    PubMed

    Tony, Maha A; Zhao, Y Q; Fu, J F; Tayeb, Aghareed M

    2008-06-01

    Alternative conditioning of aluminium-based drinking water treatment sludge using Fenton reagent (Fe2+/H2O2) was examined in this study. Focuses were placed on effectiveness and factors to affect such novel application of Fenton process. Experiments have demonstrated that considerable improvement of alum sludge dewaterability evaluated by capillary suction time (CST) can be obtained at the relative low concentrations of Fenton reagent. A Box-Behnken experimental design based on the response surface methodology was applied to evaluate the optimum of the influencing variables, i.e. iron concentration, hydrogen peroxide concentration and pH. The optimal values for Fe2+, H2O2, and pH are 21 mg g(-1)DS(-1)(dry solids), 105 mg g(-1)DS(-1) and 6, respectively, at which the CST reduction efficiency of 48+/-3% can be achieved, this agreed with that predicted by an established polynomial model in this study.

  8. Influence of stocking density on the vermicomposting of an effluent treatment plant sludge amended with cow dung.

    PubMed

    Yadav, Anoop; Garg, V K

    2016-07-01

    This paper reports the effect of earthworm population density on the vermicomposting of effluent treatment plant sludge of a bakery industry. Four waste mixtures containing 0, 10, 20, and 30 % sludge along with cow dung with five different worm population densities were established for 14 weeks under controlled moisture and temperature conditions. The results showed that average worm biomass, growth and cocoon production were lesser at higher population densities. Sexual maturity was attained in 3rd to 5th week in all waste mixtures. Worm growth was inversely related to worm population density in the waste mixture. Results also indicated that lower worm population is favorable to worm biomass production. On the other hand, mineralization and stabilization of the waste mixtures were more at higher worm populations.

  9. Effect of ultrasound, low-temperature thermal and alkali pre-treatments on waste activated sludge rheology, hygienization and methane potential.

    PubMed

    Ruiz-Hernando, M; Martín-Díaz, J; Labanda, J; Mata-Alvarez, J; Llorens, J; Lucena, F; Astals, S

    2014-09-15

    Waste activated sludge is slower to biodegrade under anaerobic conditions than is primary sludge due to the glycan strands present in microbial cell walls. The use of pre-treatments may help to disrupt cell membranes and improve waste activated sludge biodegradability. In the present study, the effect of ultrasound, low-temperature thermal and alkali pre-treatments on the rheology, hygienization and biodegradability of waste activated sludge was evaluated. The optimum condition of each pre-treatment was selected based on rheological criteria (reduction of steady state viscosity) and hygienization levels (reduction of Escherichia coli, somatic coliphages and spores of sulfite-reducing clostridia). The three pre-treatments were able to reduce the viscosity of the sludge, and this reduction was greater with increasing treatment intensity. However, only the alkali and thermal conditioning allowed the hygienization of the sludge, whereas the ultrasonication did not exhibit any notorious effect on microbial indicators populations. The selected optimum conditions were as follows: 27,000 kJ/kg TS for the ultrasound, 80 °C during 15 min for the thermal and 157 g NaOH/kg TS for the alkali. Afterward, the specific methane production was evaluated through biomethane potential tests at the specified optimum conditions. The alkali pre-treatment exhibited the greatest methane production increase (34%) followed by the ultrasonication (13%), whereas the thermal pre-treatment presented a methane potential similar to the untreated sludge. Finally, an assessment of the different treatment scenarios was conducted considering the results together with an energy balance, which revealed that the ultrasound and alkali treatments entailed higher costs.

  10. Evolution of phosphorus complexation and mineralogy during (hydro)thermal treatments of activated and anaerobically digested sludge: Insights from sequential extraction and P K-edge XANES.

    PubMed

    Huang, Rixiang; Tang, Yuanzhi

    2016-09-01

    (Hydro)thermal treatments of sewage sludge is a promising option that can simultaneously target safe waste disposal, energy recovery, and nutrient recovery/recycling. The speciation of phosphorus (P) in sludge is of great relevance to P reclamation/recycling and soil application of sludge-derived products, thus it is critical to understand the effects of different treatment techniques and conditions on P speciation. This study systematically characterized P speciation (i.e. complexation and mineral forms) in chars derived from pyrolysis and hydrothermal carbonization (HTC) of municipal sewage sludges. Combined sequential extraction and P K-edge X-ray absorption near edge structure (XANES) spectroscopy analysis revealed the dependence of P transformation on treatment conditions and metal composition in the feedstocks. Pyrolysis of sludges decreased the relative abundance of phytic acid while increased the abundance of Al-associated P. HTC thoroughly homogenized and exposed P for interaction with various metals/minerals, with the final P speciation closely related to the composition/speciation of metals and their affinities to P. Results from this study revealed the mechanisms of P transformation during (hydro)thermal treatments of sewage sludges, and might be applicable to other biosolids. It also provided fundamental knowledge basis for the design and selection of waste management strategies for better P (re)cycling and reclamation.

  11. Project summary: Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    The City of Indianapolis, Indiana, was required to construct advanced wastewater treatment facilities at the existing Belmont Wastewater Treatment Plant. The most cost effective site for these new treatment facilities was the 10 sludge lagoons containing 420,000 cubic meters (111 million gallons) of digested sewage sludge stored for up to 50 years. The project consisted of the following major tasks: (1) obtaining approval from regulatory agencies; (2) obtaining cooperation of landowners and farmers; (3) removing, transporting, and applying the lagooned sludge to soil; and (4) monitoring the impact on crops.

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

    PubMed

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

    2008-01-01

    Survival of Escherichia coli O157:H7 strain isolated from milk in Poland and an environmental E. coli strain in wastewater from Garwolin and Łowicz 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 Łowicz 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.

  13. Advances in sarcoma diagnostics and treatment

    PubMed Central

    Dancsok, Amanda R; Asleh-Aburaya, Karama; Nielsen, Torsten O

    2017-01-01

    The heterogeneity of sarcomas with regard to molecular genesis, histology, clinical characteristics, and response to treatment makes management of these rare yet diverse neoplasms particularly challenging. This review encompasses recent developments in sarcoma diagnostics and treatment, including cytotoxic, targeted, epigenetic, and immune therapy agents. In the past year, groups internationally explored the impact of adding mandatory molecular testing to histological diagnosis, reporting some changes in diagnosis and/or management; however, the impact on outcomes could not be adequately assessed. Transcriptome sequencing techniques have brought forward new diagnostic tools for identifying fusions and/or characterizing unclassified entities. Next-generation sequencing and advanced molecular techniques were also applied to identify potential targets for directed and epigenetic therapy, where preclinical studies reported results for agents active within the receptor tyrosine kinase, mTOR, Notch, Wnt, Hedgehog, Hsp90, and MDM2 signaling networks. At the level of clinical practice, modest developments were seen for some sarcoma subtypes in conventional chemotherapy and in therapies targeting the pathways activated by various receptor tyrosine kinases. In the burgeoning field of immune therapy, sarcoma work is in its infancy; however, elaborate protocols for immune stimulation are being explored, and checkpoint blockade agents advance from preclinical models to clinical studies. PMID:27732970

  14. SLUDGE TREATMENT PROJECT KOP DISPOSITION - THERMAL AND GAS ANALYSIS FOR THE COLD VACUUM DRYING FACILITY

    SciTech Connect

    SWENSON JA; CROWE RD; APTHORPE R; PLYS MG

    2010-03-09

    The purpose of this document is to present conceptual design phase thermal process calculations that support the process design and process safety basis for the cold vacuum drying of K Basin KOP material. This document is intended to demonstrate that the conceptual approach: (1) Represents a workable process design that is suitable for development in preliminary design; and (2) Will support formal safety documentation to be prepared during the definitive design phase to establish an acceptable safety basis. The Sludge Treatment Project (STP) is responsible for the disposition of Knock Out Pot (KOP) sludge within the 105-K West (KW) Basin. KOP sludge consists of size segregated material (primarily canister particulate) from the fuel and scrap cleaning process used in the Spent Nuclear Fuel process at K Basin. The KOP sludge will be pre-treated to remove fines and some of the constituents containing chemically bound water, after which it is referred to as KOP material. The KOP material will then be loaded into a Multi-Canister Overpack (MCO), dried at the Cold Vacuum Drying Facility (CVDF) and stored in the Canister Storage Building (CSB). This process is patterned after the successful drying of 2100 metric tons of spent fuel, and uses the same facilities and much of the same equipment that was used for drying fuel and scrap. Table ES-l present similarities and differences between KOP material and fuel and between MCOs loaded with these materials. The potential content of bound water bearing constituents limits the mass ofKOP material in an MCO load to a fraction of that in an MCO containing fuel and scrap; however, the small particle size of the KOP material causes the surface area to be significantly higher. This relatively large reactive surface area represents an input to the KOP thermal calculations that is significantly different from the calculations for fuel MCOs. The conceptual design provides for a copper insert block that limits the volume available to

  15. Microbial Community Structure of Activated Sludge in Treatment Plants with Different Wastewater Compositions

    PubMed Central

    Shchegolkova, Nataliya M.; Krasnov, George S.; Belova, Anastasia A.; Dmitriev, Alexey A.; Kharitonov, Sergey L.; Klimina, Kseniya M.; Melnikova, Nataliya V.; Kudryavtseva, Anna V.

    2016-01-01

    Activated sludge (AS) plays a crucial role in the treatment of domestic and industrial wastewater. AS is a biocenosis of microorganisms capable of degrading various pollutants, including organic compounds, toxicants, and xenobiotics. We performed 16S rRNA gene sequencing of AS and incoming sewage in three wastewater treatment plants (WWTPs) responsible for processing sewage with different origins: municipal wastewater, slaughterhouse wastewater, and refinery sewage. In contrast to incoming wastewater, the taxonomic structure of AS biocenosis was found to become stable in time, and each WWTP demonstrated a unique taxonomic pattern. Most pathogenic microorganisms (Streptococcus, Trichococcus, etc.), which are abundantly represented in incoming sewage, were significantly decreased in AS of all WWTPs, except for the slaughterhouse wastewater. Additional load of bioreactors with influent rich in petroleum products and organic matter was associated with the increase of bacteria responsible for AS bulking and foaming. Here, we present a novel approach enabling the prediction of the metabolic potential of bacterial communities based on their taxonomic structures and MetaCyc database data. We developed a software application, XeDetect, to implement this approach. Using XeDetect, we found that the metabolic potential of the three bacterial communities clearly reflected the substrate composition. We revealed that the microorganisms responsible for AS bulking and foaming (most abundant in AS of slaughterhouse wastewater) played a leading role in the degradation of substrates such as fatty acids, amino acids, and other bioorganic compounds. Moreover, we discovered that the chemical, rather than the bacterial composition of the incoming wastewater was the main factor in AS structure formation. XeDetect (freely available: https://sourceforge.net/projects/xedetect) represents a novel powerful tool for the analysis of the metabolic capacity of bacterial communities. The tool will

  16. Microbial Community Structure of Activated Sludge in Treatment Plants with Different Wastewater Compositions.

    PubMed

    Shchegolkova, Nataliya M; Krasnov, George S; Belova, Anastasia A; Dmitriev, Alexey A; Kharitonov, Sergey L; Klimina, Kseniya M; Melnikova, Nataliya V; Kudryavtseva, Anna V

    2016-01-01

    Activated sludge (AS) plays a crucial role in the treatment of domestic and industrial wastewater. AS is a biocenosis of microorganisms capable of degrading various pollutants, including organic compounds, toxicants, and xenobiotics. We performed 16S rRNA gene sequencing of AS and incoming sewage in three wastewater treatment plants (WWTPs) responsible for processing sewage with different origins: municipal wastewater, slaughterhouse wastewater, and refinery sewage. In contrast to incoming wastewater, the taxonomic structure of AS biocenosis was found to become stable in time, and each WWTP demonstrated a unique taxonomic pattern. Most pathogenic microorganisms (Streptococcus, Trichococcus, etc.), which are abundantly represented in incoming sewage, were significantly decreased in AS of all WWTPs, except for the slaughterhouse wastewater. Additional load of bioreactors with influent rich in petroleum products and organic matter was associated with the increase of bacteria responsible for AS bulking and foaming. Here, we present a novel approach enabling the prediction of the metabolic potential of bacterial communities based on their taxonomic structures and MetaCyc database data. We developed a software application, XeDetect, to implement this approach. Using XeDetect, we found that the metabolic potential of the three bacterial communities clearly reflected the substrate composition. We revealed that the microorganisms responsible for AS bulking and foaming (most abundant in AS of slaughterhouse wastewater) played a leading role in the degradation of substrates such as fatty acids, amino acids, and other bioorganic compounds. Moreover, we discovered that the chemical, rather than the bacterial composition of the incoming wastewater was the main factor in AS structure formation. XeDetect (freely available: https://sourceforge.net/projects/xedetect) represents a novel powerful tool for the analysis of the metabolic capacity of bacterial communities. The tool will

  17. Treatment of the biodegradable fraction of used disposable diapers by co-digestion with waste activated sludge.

    PubMed

    Torrijos, M; Sousbie, P; Rouez, M; Lemunier, M; Lessard, Y; Galtier, L; Simao, A; Steyer, J P

    2014-03-01

    The results presented in this paper are part of a project aimed at designing an original solution for the treatment of used disposable diapers permitting the recycling of materials and the recovery of energy. Diapers must be collected separately at source and transported to an industrial facility to undergo special treatment which makes it possible to separate plastics and to recover a biodegradable fraction (BFD) made up mainly of cellulose. The methane yield of BFD was measured and found to be 280 ml CH4/g VSfed on average. 150 kg of dry BFD can be retrieved from the treatment of one ton of used disposable diapers, representing an energy potential of about 400 kW h of total energy or 130 kW h of electricity. As the treatment process for used diapers requires very high volumes of water, the setting up of the diaper treatment facility at a wastewater treatment plant already equipped with an anaerobic digester offers the advantages of optimizing water use as well as its further treatment and, also, the anaerobic digestion of BFD. The lab-scale experiments in a SBR showed that BFD co-digestion with sewage sludge (38% BFD and 62% waste activated sludge on volatile solids basis) was feasible. However, special attention should be paid to problems that might arise from the addition of BFD to a digester treating WAS such as insufficient mixing or floating particles leading to the accumulation of untreated solids in the digester.

  18. Effect of H2O2 dosing strategy on sludge pretreatment by microwave-H2O2 advanced oxidation process.

    PubMed

    Wang, Yawei; Wei, Yuansong; Liu, Junxin

    2009-09-30

    Considering characteristics of breaking down H(2)O(2) into water and molecular oxygen by catalase in waste activated sludge (WAS), the effect of H(2)O(2) dosing strategy on sludge pretreatment by the advanced oxidation process (AOP) of microwave-H(2)O(2) was investigated by batch experiments for optimizing H(2)O(2) dosage. Results showed that the catalase in sludge was active at the low temperature range between 15 degrees C and 45 degrees C, and gradually lost activity from 60 degrees C to 80 degrees C. Therefore, the H(2)O(2) was dosed at 80 degrees C, to which the waste activated sludge was first heated by the microwave (MW), and then the sludge dosed with H(2)O(2) was continuously heated till 100 degrees C by the microwave. Results at different H(2)O(2) dosages showed that the higher the H(2)O(2) dosing ratio was, the more the SCOD and total organic carbon (TOC) were released into the supernatant, and the optimum range of H(2)O(2)/TCOD ratio should be between 0.1 and 1.0. The percentages of consumed H(2)O(2) in the AOP of microwave and H(2)O(2) treating the WAS were 25.38%, 22.53%, 14.82%, 13.61% and 19.63% at different H(2)O(2)/TCOD dosing ratios of 0.1, 0.5, 1, 2, 4, respectively. Along with the increasing H(2)O(2)/TCOD ratio, the contents of TCOD on particles, soluble substances and mineralization increased and the TCOD distribution on solids decreased.

  19. Recent advances in treatment of aplastic anemia.

    PubMed

    Shin, Seung Hwan; Lee, Sung Eun; Lee, Jong Wook

    2014-11-01

    Recent advances in the treatment of aplastic anemia (AA) made most of patients to expect to achieve a long-term survival. Allogeneic stem cell transplantation (SCT) from HLA-matched sibling donor (MSD-SCT) is a preferred first-line treatment option for younger patients with severe or very severe AA, whereas immunosuppressive treatment (IST) is an alternative option for others. Horse anti-thymocyte globuline (ATG) with cyclosporin A (CsA) had been a standard IST regimen with acceptable response rate. Recently, horse ATG had been not available and replaced with rabbit ATG in most countries. Subsequently, recent comparative studies showed that the outcomes of patients who received rabbit ATG/CsA were similar or inferior compared to those who received horse ATG/CsA. Therefore, further studies to improve the outcomes of IST, including additional eltrombopag, are necessary. On the other hand, the upper age limit of patients who are able to receive MSD-SCT as first-line treatment is a current issue because of favorable outcomes of MSD-SCT of older patients using fludarabine-based conditioning. In addition, further studies to improve the outcomes of patients who receive allogeneic SCT from alternative donors are needed. In this review, current issues and the newly emerging trends that may improve their outcomes in near futures will be discussed focusing the management of patients with AA.

  20. Occurrence, distribution, and potential affecting factors of organophosphate flame retardants in sewage sludge of wastewater treatment plants in Henan Province, Central China.

    PubMed

    Pang, Long; Yuan, Yiting; He, Han; Liang, Kang; Zhang, Hongzhong; Zhao, Jihong

    2016-06-01

    Organophosphate esters (OPEs) are widely used as flame retardants. In this study, the occurrence and distribution of six OPEs were investigated in sewage sludge from 24 wastewater treatment plants (WWTPs) in 18 cities of Henan province, Central China. The results indicated that all target OPEs were detected in the sludge samples with the detection rate of 95.8%, except tris(dichloropropyl)phosphate (TDCP). The total concentration of the six OPEs ranged from 38.6 to 508 μg kg(-1). Tris(2-chloroethyl)phosphate (TCEP), tris(2-butoxyethyl)phosphate (TBEP), and tris(2-chloroiso-propyl)phosphate (TCPP) were found to be predominant, with concentrations ranging from 2.50 to 203, 1.60 to 383, and 6.70-161 μg kg(-1), respectively. The potential factors affecting OPE levels in sewage sludge, such as wastewater source, sludge characteristics, operational conditions, treatment techniques, and total organic carbon (TOC) of sludge in WWTPs were investigated. The results indicated that the total concentration of OPEs in sewage sludge has no significant relationship with the individual parameters (p > 0.05). However, significant correlations were found between triphenyl phosphate (TPhP) level and treatment capacity (R = 0.484, p < 0.05), processing volume (R = 0.495, p < 0.05), and serving population (R = 0.591, p < 0.05). Furthermore, the relationship between treatment techniques and the total concentration of OPEs in sewage sludge was also investigated in this study, and the results illustrated that the levels of OPEs in sludge were independent of the solid retention time (SRT).

  1. Evaluation of solidification/stabilization for treatment of a petroleum hydrocarbon contaminated sludge from Fort Polk Army Installation, Louisiana. Final report

    SciTech Connect

    Channell, M.G.; Preston, K.T.

    1996-09-01

    In the course of normal operations and training, soldiers and civilian personnel operate many Army vehicles on a day-today basis. These vehicles must be cleaned before they can be returned to the motor pool area of an Army base. The cleaning of these vehicles bas posed a problem with the operation and maintenance of oil/water separators located at vehicle washrack facilities. An oily sludge forms in the oil/water separator and is hard to handle and cannot be disposed of in an ordinary manner. This study used solidification/stabilization to treat the oily sludge found in the vehicle washrack oil/water separators. Solidification/stabilization is usually used to treat soils and sludges that contain heavy metals. Organic compounds, such as petroleum hydrocarbons found in the sludge, interfere with the setting of the solidification binding materials and thus produce a material that is not desirable for a treatment alternative. This study incorporates the use of dicalcium silicate as an additive to the solidification process to increase the strength and reduce the leachability of the petroleum hydrocarbons found in the sludge. This study shows that dicalcium silicate improves the handling characteristics of the sludge and reduces the leachability of the contaminants from the washrack sludge.

  2. Effects of ultrasound pretreatment on the characteristic evolutions of drinking water treatment sludge and its impact on coagulation property of sludge recycling process.

    PubMed

    Zhou, Zhiwei; Yang, Yanling; Li, Xing

    2015-11-01

    Large amounts of drinking water treatment sludge (DWTS) are produced during the flocculation or flotation process. The recycling of DWTS is important for reducing and reclaiming the waste residues from drinking water treatment. To improve the coagulation step of the DWTS recycling process, power ultrasound was used as a pretreatment to disintegrate the DWTS and degrade or inactivate the constituents that are difficult to remove by coagulation. The effects of ultrasound pretreatment on the characteristics of DWTS, including the extent of disintegration, variation in DWTS floc characteristics, and DWTS dewaterability, were investigated. The capacity of the recycling process to remove particulates and organic matter from low-turbidity surface water compared to a control treatment process without DWTS was subsequently evaluated. The coagulation mechanism was further investigated by analyzing the formation, breakage, and re-growth of re-coagulated flocs. Our results indicated that under the low energy density applied (0.03-0.033 W/mL) for less than 15 min at a frequency of 160 kHz, the level of organic solubilization was less elevated, which was evidenced by the lower release of proteins and polysaccharides and lower fluorescence intensities of humic- and protein-like substances. The applied ultrasound conditions had an adverse effect on the dewaterability of the DWTS. Ultrasound pretreatment had no significant impact on the pH or surface charge of the DWTS flocs, whereas particle size decreased slightly and the specific surface area was moderately increased. The pollution removal capacity decreased somewhat for the recycled sonicated DWTS treatment, which was primarily ascribed to organic solubilization rather than variability in the floc characteristics of sonicated DWTS. The main coagulation mechanism was floc sweeping and physical adsorption. The breakage process of the flocs formed by the recycling process displayed distinct irreversibility, and the flocs were

  3. Recycling of blast furnace sludge by briquetting with starch binder: Waste gas from thermal treatment utilizable as a fuel.

    PubMed

    Drobíková, Klára; Plachá, Daniela; Motyka, Oldřich; Gabor, Roman; Kutláková, Kateřina Mamulová; Vallová, Silvie; Seidlerová, Jana

    2016-02-01

    Steel plants generate significant amounts of wastes such as sludge, slag, and dust. Blast furnace sludge is a fine-grained waste characterized as hazardous and affecting the environment negatively. Briquetting is one of the possible ways of recycling of this waste while the formed briquettes serve as a feed material to the blast furnace. Several binders, both organic and inorganic, had been assessed, however, only the solid product had been analysed. The aim of this study was to assess the possibilities of briquetting using commonly available laundry starch as a binder while evaluating the possible utilization of the waste gas originating from the thermal treatment of the briquettes. Briquettes (100g) were formed with the admixture of starch (UNIPRET) and their mechanical properties were analysed. Consequently, they were subjected to thermal treatment of 900, 1000 and 1100°C with retention period of 40min during which was the waste gas collected and its content analysed using gas chromatography. Dependency of the concentration of the compounds forming the waste gas on the temperature used was determined using Principal component analysis (PCA) and correlation matrix. Starch was found to be a very good binder and reduction agent, it was confirmed that metallic iron was formed during the thermal treatment. Approximately 20l of waste gas was obtained from the treatment of one briquette; main compounds were methane and hydrogen rendering the waste gas utilizable as a fuel while the greatest yield was during the lowest temperatures. Preparation of blast furnace sludge briquettes using starch as a binder and their thermal treatment represents a suitable method for recycling of this type of metallurgical waste. Moreover, the composition of the resulting gas is favourable for its use as a fuel.

  4. Effects of sludge retention time and biosurfactant on the treatment of polyaromatic hydrocarbon (PAH) in a petrochemical industry wastewater.

    PubMed

    Sponza, D T; Gok, O

    2011-01-01

    A laboratory-scale aerobic activated sludge reactor (AASR) system was employed to investigate the effects of sludge retention time (SRT) on the removal of three polyaromatic hydrocarbons (PAHs) with low benzene rings [(acenaphthene (ACT), fluorene (FLN) and phenanthrene (PHE)] and six PAHs with high benzene rings [(benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene (DahA), benzo[g,h,i]perylene (BghiP)] in the presence of rhamnolipid (RD), emulsan (EM) and surfactine (SR) biosurfactants. This study showed that biosurfactants enhance the PAH biodegradation by increasing the biomass growth. RD exhibits a better performance than the other biosurfactants in the removal of the chemical oxygen demand (COD) and PAHs. At a RD concentration of 15 mg/L aerobic treatment for 25 days, SRT was enough to remove over 95% of total PAHs, and COD(dis). Under the same conditions 75% of COD originating from the inert organics (COD(inert)) and 96% of COD originating from the inert soluble microbial products (COD(imp)) were removed. At 25 days SRT and 15 mg/L RD concentration, about 88% of PAHs were biodegraded by the AASR system, 4% were accumulated in the system, 3% were released in the effluent, and 5% remained in the waste sludge.

  5. Occurrence and distribution of organophosphate flame retardants/plasticizers in wastewater treatment plant sludges from the Pearl River Delta, China.

    PubMed

    Zeng, Xiangying; He, Lixiong; Cao, Shuxia; Ma, Shengtao; Yu, Zhiqiang; Gui, Hongyan; Sheng, Guoying; Fu, Jiamo

    2014-08-01

    Organophosphate esters (OPs) are widely used as flame retardants or plasticizers and are ubiquitously distributed in the environment. In the present study, the occurrence and distribution of 7 widely used OPs were analyzed in sludge samples collected from 19 municipal wastewater treatment plants in the Pearl River Delta, South China. All analytes were detected in these samples, and the total concentration of OPs ranged from 96.7 µg/kg to 1312.9 µg/kg dry weight, with a mean value of 420.1 µg/kg dry weight. In most sludge samples OPs exhibited a similar distribution pattern, for example, tris(2-butoxyethyl) phosphate (TBEP) and triphenyl phosphate (TPhP) were identified as the dominant compounds. However, the results also indicated significantly higher levels of OPs in specific sludges, such as tri-n-butyl phosphate (804.9 µg/kg), TBEP (783.7 µg/kg), TPhP (656.7 µg/kg), and tritolyl phosphate (265.0 µg/kg), which implied different discharge sources in the studied areas.

  6. Effect of magnetic nanoparticles on the performance of activated sludge treatment system.

    PubMed

    Ni, Shou-Qing; Ni, Jianyuan; Yang, Ning; Wang, Juan

    2013-09-01

    Both short-term and long-term exposure experiments were carried out to investigate the influence of magnetic nanoparticles (NPs) on activated sludge. The short-term presence of 50-200 mg/L of NPs decreased total nitrogen (TN) removal efficiencies, resulted from the acute toxicity of a shock load of NPs. However, long-term exposure of 50 mg/L magnetic NPs were observed to significantly improve TN removal efficiency, partially due to the self-repair function of activated sludge and magnetic-induced bio-effect. Sludge properties and extracellular polymer substrates secretion were affected. Additional investigations with enzyme and FISH assays indicated that short-term exposure of 50 mg/L magnetic NPs led to the abatement of nitrifying bacteria. However, the activities of the enzyme nitrite oxidoreductase and key denitrifying enzymes were increased after long-term exposure.

  7. Solidified structure and leaching properties of metallurgical wastewater treatment sludge after solidification/stabilization process.

    PubMed

    Radovanović, Dragana Đ; Kamberović, Željko J; Korać, Marija S; Rogan, Jelena R

    2016-01-01

    The presented study investigates solidification/stabilization process of hazardous heavy metals/arsenic sludge, generated after the treatment of the wastewater from a primary copper smelter. Fly ash and fly ash with addition of hydrated lime and Portland composite cement were studied as potential binders. The effectiveness of the process was evaluated by unconfined compressive strength (UCS) testing, leaching tests (EN 12457-4 and TCLP) and acid neutralization capacity (ANC) test. It was found that introduction of cement into the systems increased the UCS, led to reduced leaching of Cu, Ni and Zn, but had a negative effect on the ANC. Gradual addition of lime resulted in decreased UCS, significant reduction of metals leaching and high ANC, due to the excess of lime that remained unreacted in pozzolanic reaction. Stabilization of more than 99% of heavy metals and 90% of arsenic has been achieved. All the samples had UCS above required value for safe disposal. In addition to standard leaching tests, solidificates were exposed to atmospheric conditions during one year in order to determine the actual leaching level of metals in real environment. It can be concluded that the EN 12457-4 test is more similar to the real environmental conditions, while the TCLP test highly exaggerates the leaching of metals. The paper also presents results of differential acid neutralization (d-AN) analysis compared with mineralogical study done by scanning electron microscopy and X-ray diffraction analysis. The d-AN coupled with Eh-pH (Pourbaix) diagrams were proven to be a new effective method for analysis of amorphous solidified structure.

  8. Biogenic metals in advanced water treatment.

    PubMed

    Hennebel, Tom; De Gusseme, Bart; Boon, Nico; Verstraete, Willy

    2009-02-01

    Microorganisms can change the oxidation state of metals and concomitantly deposit metal oxides and zerovalent metals on or into their cells. The microbial mechanisms involved in these processes have been extensively studied in natural environments, and researchers have recently gained interest in the applications of microbe-metal interactions in biotechnology. Because of their specific characteristics, such as high specific surface areas and high catalytic reactivity, biogenic metals offer promising perspectives for the sorption and (bio)degradation of contaminants. In this review, the precipitation of biogenic manganese and iron species and the microbial reduction of precious metals, such as palladium, platinum, silver and gold, are discussed with specific attention to the application of these biogenic metals in innovative remediation technologies in advanced water treatment.

  9. Sequential chemical treatment of radium species in TENORM waste sludge produced from oil and natural gas production.

    PubMed

    El Afifi, E M; Awwad, N S; Hilal, M A

    2009-01-30

    This paper is dedicated to the treatment of sludge occurring in frame of the Egyptian produced from oil and gas production. The activity levels of three radium isotopes: Ra-226 (of U-series), Ra-228 and Ra-224 (of Th-series) in the solid TENORM waste (sludge) were first evaluated and followed by a sequential treatment for all radium species (fractions) presented in TENORM. The sequential treatment was carried out based on two approaches 'A' and 'B' using different chemical solutions. The results obtained indicate that the activity levels of all radium isotopes (Ra-226, Ra-228 and Ra-224) of the environmental interest in the TENORM waste sludge were elevated with regard to exemption levels established by IAEA [International Atomic Energy Agency (IAEA), International basic safety standards for the protection against ionizing radiation and for the safety of radiation sources. GOV/2715/Vienna, 1994]. Each approach of the sequential treatment was performed through four steps using different chemical solutions to reduce the activity concentration of radium in a large extent. Most of the leached radium was found as an oxidizable Ra species. The actual removal % leached using a