Sample records for sludge treatment system

  1. Economic assessment of sludge handling and environmental impact of sludge treatment in a reed bed system. (United States)

    Nielsen, Steen


    The effect on the environment of the establishment and operation of a sludge treatment reed bed system (STRB) is quite limited compared to mechanical sludge dewatering, with its accompanying use of energy and chemicals. The assessment presented here of the investment, operation and maintenance costs of a typical STRB, and of the related environmental impact, is based on the experiences gained from the operation of a large number of STRB in Denmark. There are differences in the environmental perspectives and costs involved in mechanical sludge dewatering and disposal on agricultural land compared to STRB. The two treatment methods were considered for comparison based on a treatment capacity of 550 tons of dry solids per year and with land application of the biosolids in Denmark. The initial capital cost for STRB is higher than a conventional mechanical system; however, an STRB would provide significant power and operating-cost savings, with a significant saving in the overall cost of the plant over 20-30 years. The assessment focuses on the use of chemicals, energy and greenhouse gas emissions and includes emptying, sludge residue quality and recycling. STRB with direct land application is the most cost-effective scenario and has the lowest environmental impact. A sludge strategy consisting of an STRB will be approximately DKK 536,894-647,636 cheaper per year than the option consisting of a new screw press or decanter.

  2. SNF sludge treatment system preliminary project execution plan

    Energy Technology Data Exchange (ETDEWEB)

    Flament, T.A.


    The Fluor Daniel Hanford, Inc. (FDH) Project Director for the Spent Nuclear Fuel (SNF) Project has requested Numatec Hanford Company (NHC) to define how Hanford would manage a new subproject to provide a process system to receive and chemically treat radioactive sludge currently stored in the 100 K Area fuel retention basins. The subproject, named the Sludge Treatment System (STS) Subproject, provides and operates facilities and equipment to chemically process K Basin sludge to meet Tank Waste Remediation System (TWRS) requirements. This document sets forth the NHC management approach for the STS Subproject and will comply with the requirements of the SNF Project Management Plan (HNF-SD-SNFPMP-011). This version of this document is intended to apply to the initial phase of the subproject and to evolve through subsequent revision to include all design, fabrication, and construction conducted on the project and the necessary management and engineering functions within the scope of the subproject. As Project Manager, NHC will perform those activities necessary to complete the STS Subproject within approved cost and schedule baselines and turn over to FDH facilities, systems, and documentation necessary for operation of the STS.

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

    DEFF Research Database (Denmark)

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


    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......, 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...

  4. Sludge treatment studies

    Energy Technology Data Exchange (ETDEWEB)

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


    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.


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    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.


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    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

  7. Evaluation of a biological wastewater treatment system combining an OSA process with ultrasound for sludge reduction. (United States)

    Romero-Pareja, P M; Aragon, C A; Quiroga, J M; Coello, M D


    Sludge production is an undesirable by-product of biological wastewater treatment. The oxic-settling-anaerobic (OSA) process constitutes one of the most promising techniques for reducing the sludge produced at the treatment plant without negative consequences for its overall performance. In the present study, the OSA process is applied in combination with ultrasound treatment, a lysis technique, in a lab-scale wastewater treatment plant to assess whether sludge reduction is enhanced as a result of mechanical treatment. Reported sludge reductions of 45.72% and 78.56% were obtained for the two regimes of combined treatment tested in this study during two respective stages: UO1 and UO2. During the UO1 stage, the general performance and nutrient removal improved, obtaining 47.28% TN removal versus 21.95% in the conventional stage. However, the performance of the system was seriously damaged during the UO2 stage. Increases in dehydrogenase and protease activities were observed during both stages. The advantages of the combined process are not necessarily economic, but operational, as US treatment acts as contributing factor in the OSA process, inducing mechanisms that lead to sludge reduction in the OSA process and improving performance parameters. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Environmental Assessment of Sewage Sludge Management – Focusing on Sludge Treatment Reed Bed Systems

    DEFF Research Database (Denmark)

    Larsen, Julie Dam

    -CEN) and 3.0 10-4 PE for STRB systems (S-STRB and S-SPA). The STRB system technology consumed fewer abiotic resources, due mainly to the fact that the mechanical treatment process requires an input of polymer coagulant, while a STRB system does not require this contribution. Furthermore, as mechanically...

  9. Improvement and prediction of OSA system performance in sludge reduction through integration with thermal and mechanical treatment. (United States)

    Nazif, Sara; Mehrdadi, Naser; Zare, Sajad; Mosavari, Sarvenaz


    The oxic-settling-anoxic (OSA) process is one of the sludge production reduction methods in the activated sludge process. In this method, sludge is stored in an anaerobic tank within the sludge return line before entrance into an aeration tank. Due to this method's flexibility in application to operating treatment plants and not being energy-consuming, its application is developing. In this research, the improvement of the OSA process is investigated via thermal and mechanical treatment in a sequencing batch reactor (SBR). A pilot-scale reactor and domestic wastewater are used. Sludge was subjected to high temperature in an anaerobic tank using a heat transformer and it was subjected to mechanical shear through mechanical mixing in the anaerobic tank. Different temperatures and voltages were tested. The OSA process reduced sludge production by 24% while the chemical oxygen demand (COD) removal rate decreased from 90% to 86%. Thermal treatment combined with the OSA process caused a maximum of 46% sludge production reduction. However temperatures above 90 °C are not recommended due to a high level of decrease in COD removal. Mechanical mixing in combination with the OSA process led to 34% sludge production reduction. The effluent quality is not affected by the OSA process itself but is slightly reduced by thermal treatment and mechanical mixing. Therefore, for reaching the maximum sludge reduction in OSA plus thermal and mechanical treatment it would be necessary to evaluate the effect of different sets of parameters on effluent quality beside the sludge reduction. For this purpose multi-layer perceptron artificial neural network models are developed to predict the effluent total suspended solids and COD removal efficiency as well as sludge production rate. The models perform well and would be useful tools in determining the optimal set of system operation parameters.

  10. Optimal policies for activated sludge treatment systems with multi effluent stream generation

    Directory of Open Access Journals (Sweden)

    Gouveia R.


    Full Text Available Most industrial processes generate liquid waste, which requires treatment prior to disposal. These processes are divided into sectors that generate effluents with time dependent characteristics. Each sector sends the effluent to wastewater treatment plants through pumping-stations. In general, activated sludge is the most suitable treatment and consists of equalization, aeration and settling tanks. During the treatment, there is an increase in the mass of microorganisms, which needs to be removed. Sludge removal represents the major operating costs for wastewater treatment plants. The objective of this work is to propose an optimization model to minimize sludge generation using a superstructure in which the streams from pumping-stations can be sent to the equalization tank. In addition, the aeration tank is divided into cells that can be fed in series and parallel. The model relies on mass balances, kinetic equations, and the resulting Nonlinear Programming problem generates the best operational strategy for the system feed streams with a high substrate removal. Reductions of up to 30 % can be achieved with the proposed strategy maintened BOD efficiency removal upper than 98 %.

  11. Assessment of a Danish sludge treatment reed bed system and a stockpile area, using substance flow analysis

    DEFF Research Database (Denmark)

    Larsen, Julie Dam; Nielsen, Steen M; Scheutz, Charlotte


    . Concentrations of carbon and nitrogen in the sludge residue residing in an STRB system changed as a function of treatment time, mainly due to mineralisation; only a negligible part was lost to reject water. Considering metals and phosphorus, the main share was accumulated in the sludge residue; only minor...... fractions were lost to mineralisation or reject water. Post-treatment in an SPA resulted in an increase in dry matter content from 24% to 32%. After treatment, the concentrations of heavy metals (lead, cadmium, nickel, zinc, copper and chromium) in the sludge residue met the threshold values stated...

  12. Comparative study of wastewater treatment and nutrient recycle via activated sludge, microalgae and combination systems. (United States)

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


    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Excess sludge reduction in activated sludge processes by integrating ultrasound treatment

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Elvira, S.; Fdz-Polanco, M.; Plaza, F. I.; Garralon, G.; Fdz-Polanco, F.


    Biological sludge produced in the activated sludge process can be minimised modifying the water line, the sludge line or the final disposal strategy. Selecting the water line the general idea is to reduce the sludge producing the yield coefficient by means of the called lysis cryptic growth process. The main techniques referenced in literature are onization, chlorination and chemical and heat treatment. Ultrasounds are widely used to increase anaerobic biodegradability but are not reported as system to control excess sludge production. (Author)


    Directory of Open Access Journals (Sweden)



    Full Text Available An activated sludge aeration tank and a sedimentation basin were used to treat Amol’s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d−1, respectively. The hydraulic retention times (HRT were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.

  15. K Basins sludge removal temporary sludge storage tank system

    Energy Technology Data Exchange (ETDEWEB)

    Mclean, M.A.


    Shipment of sludge from the K Basins to a disposal site is now targeted for August 2000. The current path forward for sludge disposal is shipment to Tank AW-105 in the Tank Waste Remediation System (TWRS). Significant issues of the feasibility of this path exist primarily due to criticality concerns and the presence of polychlorinated biphenyls (PCBS) in the sludge at levels that trigger regulation under the Toxic Substance Control Act. Introduction of PCBs into the TWRS processes could potentially involve significant design and operational impacts to both the Spent Nuclear Fuel and TWRS projects if technical and regulatory issues related to PCB treatment cannot be satisfactorily resolved. Concerns of meeting the TWRS acceptance criteria have evolved such that new storage tanks for the K Basins sludge may be the best option for storage prior to vitrification of the sludge. A reconunendation for the final disposition of the sludge is scheduled for June 30, 1997. To support this decision process, this project was developed. This project provides a preconceptual design package including preconceptual designs and cost estimates for the temporary sludge storage tanks. Development of cost estimates for the design and construction of sludge storage systems is required to help evaluate a recommendation for the final disposition of the K Basin sludge.

  16. Integrating microalgae tertiary treatment into activated sludge systems for energy and nutrients recovery from wastewater. (United States)

    Arias, Dulce Maria; Solé-Bundó, Maria; Garfí, Marianna; Ferrer, Ivet; García, Joan; Uggetti, Enrica


    In this study, microalgae digestate and secondary effluent were used to grow microalgae in a tertiary wastewater treatment, and then, the biomass was co-digested for biogas generation. A 30L closed-photobioreactor was used for microalgae cultivation. The biomass, mainly composed by Scenedesmus sp., reached and maintained a concentration of 1.1gTSS/L during 30days. A complete removal of N-NH4+ and P-PO43- and high nitrates and organic matter removals were achieved (58% N-NO3- and 70% COD) with 8d of HRT. The potential biogas production of the cultivated microalgae was determined in batch tests. To improve their biodegradability, a novel method combining their co-digestion with activated sludge after a simultaneous autohydrolysis co-pretreatment was evaluated. After the co-pretreatment, the methane yield increased by 130%. Thus, integrating microalgae tertiary treatment into activated sludge systems is a promising and feasible solution to recover energy and nutrients from waste, improving wastewater treatment plants sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Operational strategy, economic and environmental performance of sludge treatment reed bed systems - based on 28 years of experience. (United States)

    Nielsen, S; Larsen, J D


    Sludge treatment reed bed (STRB) systems have been used for dewatering and mineralisation of sludge in Europe since 1988. STRB systems provide substantial environmental, economic, and operational benefits compared to mechanical sludge dewatering solutions such as belt presses and centrifuges. They require less energy, no chemicals, reduce the sludge volume and produce bio solids with dry solid contents up to 20-40% under Danish climate conditions, depending on the sludge quality. Experience has shown that sludge treated in STRBs represents a high quality product with a low content of pathogens and hazardous organic compounds, qualities that make it suitable for recycling on agricultural land. The upfront capital cost for STRBs are often higher compared to mechanical dewatering devices. However, the operational expenses (OPEX) (including energy, chemicals, bio solid handling) are significantly lower compared to conventional mechanical dewatering devices, delivering an economic break-even of about 3-5 years. This paper provides an overview of the operation and maintenance costs and environmental benefits of a typical STRB based on the experiences gained from the operation of a large number of STRBs with yearly treatment capacities between 100 and 3,000 tonnes of dry solid up to approximately 250,000 PE in Denmark and Europe.

  18. Net energy production and emissions mitigation of domestic wastewater treatment system: a comparison of different biogas-sludge use alternatives. (United States)

    Chen, Shaoqing; Chen, Bin


    Wastewater treatment systems are increasingly designed for the recovery of valuable chemicals and energy in addition to waste stream disposal. Herein, the life-cycle energy production and emissions mitigation of a typical domestic wastewater treatment system were assessed, in which different combinations of biogas use and sludge processing lines for industrial or household applications were considered. The results suggested that the reuse of biogas and sludge was so important in the system's overall energy balance and environmental performance that it may offset the cost in the plant's installation and operation. Combined heat and power and household utilization were two prior options for net energy production, provided an ideal power conversion efficiency and biogas production. The joint application of household biogas use and sludge nutrient processing achieved both high net energy production and significant environmental remediation across all impact categories, representing the optimal tradeoff for domestic wastewater treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. K basins sludge removal sludge pretreatment system

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.L.


    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.

  20. Development of alum sludge-based constructed wetland: an innovative and cost effective system for wastewater treatment. (United States)

    Zhao, Y Q; Babatunde, A O; Zhao, X H; Li, W C


    This article describes a research attempt to integrate the dewatered alum sludge, a residual by-product of drinking water treatment process, into a constructed wetland (CW) system for the purpose of enhancing the wastewater treatment performance, thus developing a so called alum sludge-based constructed wetland system. A multi-dimensional research project including the batch tests of phosphorus (P) adsorption onto alum sludge followed by the model CWs trials of single and multi-stage CWs, has been conducted since 2004. It has been successfully demonstrated that the alum sludge-based CW is capable of enhanced and simultaneous removal of P and organic matter (in terms of BOD5 and COD), particularly from medium and high strength wastewater. The sludge cakes act as the carrier for developing biofilm for organics removal and also serve as adsorbent to enhance P immobilization. Batch P-adsorption tests revealed that the alum sludge tested possesses excellent P-adsorption ability of 14.3 mg-P/g x sludge (in dry solids) at pH 7.0 with the adsorption favored at lower pH. The results obtained in a 4-stage treatment wetland system suggest that high removal efficiencies of 90.4% for COD, 88.0% for BOD5, 90.6% for SS, 76.5% for TN and 91.9% for PO4(3-)-P under hydraulic loading of 0.36 m3/m2 x d can be achieved. The field demonstration study of this pioneering development is now underway.

  1. A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems. (United States)

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


    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.

  2. A Cost-Effectiveness Analysis of Seminatural Wetlands and Activated Sludge Wastewater-Treatment Systems (United States)

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


    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.

  3. Community analysis of ammonia-oxidizing bacteria in activated sludge of eight wastewater treatment systems. (United States)

    Wang, Xiaohui; Wen, Xianghua; Criddle, Craig; Wells, George; Zhang, Jie; Zhao, Yin


    We investigated the communities of ammonia-oxidizing bacteria (AOB) in activated sludge collected from eight wastewater treatment systems using polymerase chain reaction (PCR) followed by terminal restriction fragment length polymorphism (T-RFLP), cloning, and sequencing of the alpha-subunit of the ammonia monooxygenase gene (amoA). The T-RFLP fingerprint analyses showed that different wastewater treatment systems harbored distinct AOB communities. However, there was no remarkable difference among the AOB T-RFLP profiles from different parts of the same system. The T-RFLP fingerprints showed that a full-scale wastewater treatment plant (WWTP) contained a larger number of dominant AOB species than a pilot-scale reactor. The source of influent affected the AOB community, and the WWTPs treating domestic wastewater contained a higher AOB diversity than those receiving mixed domestic and industrial wastewater. However, the AOB community structure was little affected by the treatment process in this study. Phylogenetic analysis of the cloned amoA genes clearly indicated that all the dominant AOB in the systems was closely related to Nitrosomonas spp. not to Nitrosospira spp. Members of the Nitrosomonas oligotropha and Nitrosomonas communis clusters were found in all samples, while members of Nitrosomonas europaea cluster occurred in some systems.

  4. Two-step upflow anaerobic sludge bed system for sewage treatment under subtropical conditions with posttreatment in waste stabilization ponds

    NARCIS (Netherlands)

    Seghezzo, L.; Trupiano, A.P.; Liberal, V.; Todd, P.G.; Figueroa, M.E.; Gutierrez, M.A.; Silva Wilches, Da A.C.; Iribarnegaray, M.; Guerra, R.G.; Arena, A.; Cuevas, C.M.; Zeeman, G.; Lettinga, G.


    A pilot-scale sewage treatment system consisting of two upflow anaerobic sludge bed (UASB) reactors followed by five waste stabilization ponds (WSPs) in series was studied under subtropical conditions. The first UASB reactor started up in only 1 mo (stable operation, high chemical oxygen demand

  5. Efficiency of wastewater treatment by a mixture of sludge and ...

    African Journals Online (AJOL)

    A combined system using the microalgae from South Africa and the sewage sludge from Algeria has been tested, in order to study the efficiency of wastewater treatment by mixtures of microalgae / activated sludge, five bioreactors were installed with different inoculation rates (microalgae / activated sludge) B1: 100% algae, ...

  6. A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems


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


    A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface wetland (FWS) 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 da...

  7. A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems


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


    A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface wetland (FWS) 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 ...

  8. Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems

    DEFF Research Database (Denmark)

    Lindblom, E.; Arnell, M.; Flores-Alsina, X.


    The objective of this paper is to model the dynamics and validate the results of nitrous oxide (N2O)emissions from three Swedish nitrifying/denitrifying, nitritation and anammox systems treating real anaerobic digester sludge liquor. The Activated Sludge Model No. 1 is extended to describe N2O...... production by both heterotrophic and autotrophic denitrification. In addition, mass transfer equations are implemented to characterize the dynamics of N2O in the water and the gas phases.The biochemical model is simulated and validated for two hydraulic patterns: (1) a sequencing batch reactor; and, (2...

  9. Co-treatment of domestic and dairy wastewater in an activated sludge system. (United States)

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


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

  10. Evaluating sedimentation problems in activated sludge treatment plants operating at complete sludge retention time. (United States)

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


    Zero net sludge growth can be achieved by complete retention of solids in activated sludge wastewater treatment, especially in high strength and biodegradable wastewaters. When increasing the solids retention time, MLSS and MLVSS concentrations reach a plateau phase and observed growth yields values tend to zero (Yobs ≈ 0). In this work, in order to evaluate sedimentation problems arised due to high MLSS concentrations and complete sludge retention operational conditions, two identical innovative slaughterhouse wastewater treatment plants were studied. Measurements of wastewaters' quality characteristics, treatment plant's operational conditions, sludge microscopic analysis and state point analysis were conducted. Results have shown that low COD/Nitrogen ratios increase sludge bulking and flotation phenomena due to accidental denitrification in clarifiers. High return activated sludge rate is essential in complete retention systems as it reduces sludge condensation and hydraulic retention time in the clarifiers. Under certain operational conditions sludge loading rates can greatly exceed literature limit values. The presented methodology is a useful tool for estimation of sedimentation problems encountered in activated sludge wastewater treatment plants with complete retention time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. K Basin sludge treatment process description

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.


    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).

  12. Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems

    DEFF Research Database (Denmark)

    Lindblom, E.; Arnell, M.; Flores-Alsina, X.


    production by both heterotrophic and autotrophic denitrification. In addition, mass transfer equations are implemented to characterize the dynamics of N2O in the water and the gas phases.The biochemical model is simulated and validated for two hydraulic patterns: (1) a sequencing batch reactor; and, (2......) a moving-bed biofilm reactor. Results show that the calibrated model is partly capable of reproducing the behaviour of N2O as well as the nitritation/nitrification/denitrification dynamics. However, the results emphasize that additional work is required before N2O emissions from sludge liquor treatment...

  13. Cavitation field analysis for an increased efficiency of ultrasonic sludge pre-treatment using a novel hydrophone system. (United States)

    Bandelin, Jochen; Lippert, Thomas; Drewes, Jörg E; Koch, Konrad


    The generation of cavitation fields for the pre-treatment of anaerobic sludge was studied by means of a novel acoustic measuring system. The influence of different reactor dimensions (i.e., choosing reaction chamber widths of 40, 60 and 80 mm) on the cavitation intensity was determined at various solid contents, flow rates and static pressures. Results suggest that the cavitation intensity is significantly reduced by the sonication of liquids with a high solid content. By increasing the pressure to 1 bar, the intensity of bubble implosions can be enhanced and the sound attenuation in the solid fraction is partly compensated compared to ambient pressure. However, a further increase in pressure to 2 bars has a detrimental effect due to the suppression of powerful bubbles. A reduction of the reactor gap permits an intensification of the treatment of waste activated sludge (WAS) by concentrating the ultrasound power from 6 to 18 dB. This effect is less relevant in digested sludge (DS) with its markedly lower total solids content (2.2% vs. 6.9% of solids in WAS). Increasing the flow rate, resulting in a flow velocity of up to 7 m/min, has no influence on the cavitation intensity. By adapting the reactor design and the static pressure to the substrate characteristics, the intensity of the sonication can be notably improved. This allows the design of sonication devices that are suitable for the intensive treatment of wastewater sludge. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Digital image processing and analysis for activated sludge wastewater treatment. (United States)

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


    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.

  15. efficiency of wastewater treatment by a mixture of sludge

    African Journals Online (AJOL)

    H. Khaldi

    Received: 27 April 2017 / Accepted: 15 July 2017 / Published online: 01 September 2017. ABSTRACT. A combined system using the microalgae from South Africa and the sewage sludge from. Algeria has been tested, in order to study the efficiency of wastewater treatment by mixtures of microalgae / activated sludge, five ...

  16. Nitrous oxide emissions from an intermittent aeration activated sludge system of an urban wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    William Z. de Mello


    Full Text Available This study investigated the emission of N2O during the sequential aerated (60-min and non-aerated (30-min stages of an intermittent aeration cycle in an activated sludge wastewater treatment plant (WWTP. N2O emission occurred during both stages; however, emission was much higher during aeration. Air stripping is the major factor controlling transfer of N2O from the sewage to the atmosphere. The N2O emissions exclusively from the aeration tank represented 0.10% of the influent total nitrogen load and the per capita emission factor was almost 3 times higher than that suggested by the IPCC for inventories of N2O emission from WWTPs.

  17. Performance of a combined system of microbial fuel cell and membrane bioreactor: wastewater treatment, sludge reduction, energy recovery and membrane fouling. (United States)

    Su, Xinying; Tian, Yu; Sun, Zhicai; Lu, Yaobin; Li, Zhipeng


    A novel combined system of sludge microbial fuel cell (S-MFC) stack and membrane bioreactor (MBR) was proposed in this study. The non-consumed sludge in the MBR sludge-fed S-MFC was recycled to the MBR. In the combined system, the COD and ammonia treatment efficiencies were more than 90% and the sludge reduction was 5.1% higher than that of the conventional MBR. It's worth noting that the energy recovery and fouling mitigation were observed in the combined system. In the single S-MFC, about 75 mg L(-1) COD could be translated to electricity during one cycle. The average voltage and maximum power production of the single S-MFC were 430 mV and 51 mWm(-2), respectively. Additionally, the combined system was able to mitigate membrane fouling by the sludge modification. Except for the content decrease (22%), S-MFC destroyed simple aromatic proteins and tryptophan protein-like substances in loosely bound extracellular polymeric substances (LB-EPS). These results indicated that effective wastewater treatment, sludge reduction, energy recovery and membrane fouling mitigation could be obtained in the combined system. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Dewatering of floated oily sludge by treatment with rhamnolipid. (United States)

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


    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Enhancement of the performance of a combined microalgae-activated sludge system for the treatment of high strength molasses wastewater. (United States)

    Tsioptsias, Costas; Lionta, Gesthimani; Deligiannis, Andreas; Samaras, Petros


    The treatment of molasses wastewater, by a combined microalgae-activated sludge process, for the simultaneous organics and total nitrogen reduction, was examined. Further enhancement of the performance of the combined process was accomplished, by means of biofilm carriers or electrocoagulation. A LED light tube was immersed into the reactor tank aiming to enhance the growth of photosynthetic microalgae, while in a similar unit, biofilm carriers were added to the system, representing a moving bed bioreactor. Exposure of the activated sludge biocommunity to light source, resulted in the growth of microalgae and photoreactors exhibited higher removal rates of total nitrogen and nitrates. However, operation at longer times resulted in low effluent quality due to the presence of microalgae cells as a result of high growth rates, and potential light shading effect. Nevertheless, the moving bed system was more beneficial than the single photoreactor, as biofilm carriers provided a self cleaning capacity of the light source, reducing the effect of microalgae deposition. Advanced treatment of the biological effluents, by electrocoagulation, increased even more the process efficiency: the combined photobioreactor and electrocoagulation process resulted in about 78% COD removal and more than 35% total nitrogen removal in the effluent, where nitrates represented almost the single form of total nitrogen. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Assessment of low concentration wastewater treatment operations with dewatered alum sludge-based sequencing batch constructed wetland system. (United States)

    Kang, Wei; Chai, Hongxiang; Xiang, Yu; Chen, Wei; Shao, Zhiyu; He, Qiang


    Competition of volatile fatty acids between anoxic denitrification and anaerobic phosphorus release is prominent. Therefore, low concentration wastewater has restricted effects on nitrogen and phosphorus removal. The purpose of this study is to treat dormitory sewage with a biochemical oxygen demand (BOD) ranging from 50 to 150 mg/L using dewatered alum sludge-based sequencing batch constructed wetland system. Vegetation in the wetland system was chosen to be Phragmites australis. Three parallel cases were carried out to assess impacts due to different hydraulic retention time (HRT) and artificial aeration. The results showed that this system is effective in removing total nitrogen (TN), ammonia nitrogen (NH3-N) and total phosphorus (TP) under different HRT. However, nitrous oxide (N2O) emission poses to be the greatest challenge in the high HRT cases. Artificial aeration could reduce N2O emission but is associated with high operational cost. Results indicate that dewatered alum sludge-based sequencing batch constructed wetland system is a promising bio-measure in the treatment of low concentration wastewater.

  1. Parasites in soil/sludge systems

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, J.R.


    The potential for the transmission of parasites, such as Entamoeba sp., schistosomes, and nematodes such as Ascaris sp., to man through the use of sewage sludges as fertilizer is reviewed. The eggs of Ascaris have been found to be the most resistant of these parasites to normal sludge treatment methods. Results of studies on the effectiveness of heat and ionizing radiation treatments reported show that a treatment of 55/sup 0/C for 1 hour or more sufficiently reduces the number of viable Ascaris eggs in seeded sludge systems. An absorbed dose of 300 kilorads radiation is more than adequate for the same purpose. However, before an unequivocal statement can be made about the effectiveness of either of these treatments in reducing viable ova in real systems, certain qualifying factors must be investigated. There are conflicting reports on the radiation sensitivities of Ascaris eggs in different stages of development. Also, irradiation of composted sludge using an electron beam was unsuccessful in rendering all naturally-occurring Ascaris ova non-viable, even at 300 kilorads. The significant differences in radiation and heat sensitivities of Ascaris eggs in compost vs liquid systems points out the need to further investigate the effects of moisture levels on these sensitivities.

  2. Effect of magnetic nanoparticles on the performance of activated sludge treatment system. (United States)

    Ni, Shou-Qing; Ni, Jianyuan; Yang, Ning; Wang, Juan


    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Supercritical water oxidation treatment of textile sludge. (United States)

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


    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.

  4. Enrichment of anammox bacteria from three sludge sources for the startup of monosodium glutamate industrial wastewater treatment system. (United States)

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


    Three activated sludges from a landfill leachate treatment plant (S1), a municipal sewage treatment plant (S2) and a monosodium glutamate (MSG) wastewater treatment plant (S3) were used as inocula to enrich anaerobic ammonium oxidation (anammox) bacteria for the startup of MSG industrial wastewater treatment system. After 360 days of cultivation using MSG wastewater, obvious anammox activity was observed in all three cultures. The maximum specific anammox activities of cultures S1, S2 and S3 were 0.11 kg N kg(-1) VSS day(-1), 0.09 kg N kg(-1) VSS day(-1) and 0.16 kg N kg(-1) VSS day(-1), respectively. Brownish-red anammox granules having diameters in the range of 0.2-1.0mm were visible in cultures S1 and S2, and large red granules having diameters in the range of 0.5-2.5mm were formed in culture S3 after 420 days of cultivation. Phylogenetic analysis of 16S rRNA genes showed that Kuenenia organisms were the dominant anammox species in all three cultures. The copy numbers of 16S rRNA genes of anammox bacteria in cultures S1, S2 and S3 were 6.8 × 10(7) copies mL(-1), 9.4 × 10(7) copies mL(-1) and 7.5 × 10(8) copies mL(-1), respectively. The results of this study demonstrated that anammox cultivation from conventional activated sludges was highly possible using MSG wastewater. Thus the anammox process has possibility of applying to the nitrogen removal from MSG wastewater. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Environmental sustainability of wastewater sludge treatments

    DEFF Research Database (Denmark)

    Boyer-Souchet, Florence; Larsen, Henrik Fred

    resources. As part of a sustainability assessment (or “best practice evaluation”), a comparison between the existing and new sludge handling techniques have been done by use of life cycle assessment (LCA).The concept of induced impacts as compared to avoided impacts when introducing a new sludge treatment...... technology is used for the environmental comparison. Emissions from the treatment of the sludge as well as energy consumption and production, chemical consumption, infrastructures and transport are taken into account. This poster will present the results of LCA’s performed on different inertisation...

  6. Characteristics of biosolids from sludge treatment wetlands for agricultural reuse

    DEFF Research Database (Denmark)

    Uggetti, Enrica; Ferrer, Ivet; Nielsen, Steen


    Sludge treatment wetlands (STW) consist of constructed wetlands systems specifically developed for sludge treatment over the last decades. Sludge dewatering and stabilisation are the main features of this technology, leading to a final product which may be recycled as an organic fertiliser or soil...... 1.5–5.0% TS to 18–26% TS. Organic matter biodegradation leads to VS around 43–46% TS and COD around 500–700 g/kg TS. The values of the DRI24 h (0.5–1.4 mg O2/g TS h) indicate that treated sludge is an almost stabilised final product. Both heavy metals and faecal bacteria indicators meet current...

  7. Investigation of Excess Sludge Generated from Activated Sludge Treatment Plant of Concentrated Latex Factories: An Investigative Case Study in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Wanrudee Wanseng


    Full Text Available Activated sludge technology has been employed for wastewater treatment in the concentrated latex factories in the south of Thailand. This paper highlights the survey results of the excess sludge generated from activated sludge treatment plants of the concentrated latex factories, including sludge generation rate, sludge characteristics, as well as sludge management and its problems. The total number of 11 factories was investigated. The findings showed that 20% of the investigated factories using activated sludge did not know how much the excess sludge generation rate was. With an in-depth investigation, the excess sludge generation rate was determined as for 28 kg/ton concentrated latex product or 10 kg/ton of field latex used in the concentrated latex factories. The excess sludge had a low C/N ratio with an average value of 4.7 and contained N, P, and K with the average of percentage values of 8.0, 2.0, and 1.0% dry basis, respectively. However, the excess sludge consisted of Zn with an average of 3.01% dry basis. 60% of the investigated factories using an activated sludge system had issues concerning the management of excess sludge. Moreover, various aspects of the excess sludge management were discussed and lessons were learned on the current excess sludge management of the concentrated latex industry in the south of Thailand.

  8. Fate and effect of naphthenic acids on oil refinery activated sludge wastewater treatment systems. (United States)

    Misiti, Teresa; Tezel, Ulas; Pavlostathis, Spyros G


    Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in oil sands process waters, crude oil, refinery wastewater and petroleum products. Crude oil, desalter brine, influent, activated sludge mixed liquor and effluent refinery samples were received from six United States refineries. The total acid number (TAN) of the six crudes tested ranged from 0.12 to 1.5 mg KOH/g crude oil and correlated to the total NA concentration in the crudes. The total NA concentration in the desalter brine, influent, activated sludge mixed liquor and effluent samples ranged from 4.2 to 40.4, 4.5 to 16.6, 9.6 to 140.3 and 2.8 to 11.6 mg NA/L, respectively. The NAs in all wastewater streams accounted for less than 16% of the total COD, indicating that many other organic compounds are present and that NAs are a minor component in refinery wastewaters. Susceptibility tests showed that none of the activated sludge heterotrophic microcosms was completely inhibited by NAs up to 400 mg/L. Growth inhibition ranging from 10 to 59% was observed in all microcosms at and above 100 mg NA/L. NAs chronically-sorbed to activated sludge mixed liquor biomass and powdered activated carbon (PAC) were recalcitrant and persistent. More than 80% of the total NAs remained in the solid phase at the end of the 10-day desorption period (five successive desorption steps). Throughout a 90-day incubation period, the total NA concentration decreased by 33 and 51% in PAC-free and PAC-containing mixed liquor microcosms, respectively. The lower molecular weight fraction of NAs was preferentially degraded in both mixed liquors. The persistence of the residual, higher molecular weight NAs is likely a combination of molecular recalcitrance and decreased bioavailability when chronically-sorbed to the biomass and/or PAC. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Zinc Regime in the Sewage Sludge-Soil-Plant System of a City Waste Water Treatment Pond

    Directory of Open Access Journals (Sweden)

    Lacatusu Radu


    Full Text Available The sewage sludge from wastewater treatment plant of Iasi, a city with 300,000 inhabitants, for domestic and industrial origin, was stored in a mud pond arranged on an area of 18,920 m2. Chemical analyzes of the sludge showed that, of all the chemical elements determined, only Zn is found at pollutant level (5739 mg∙kg-1, i.e. almost 30 times more than the maximum allowable limit for Zn in soil and 45 times more than the Zn content of the soil on which the mud pond has been set. Over time, the content of Zn in the mud pond, but also from soil to which it has been placed, has become upper the normal content of the surrounding soil up to a depth of 260 cm. On the other hand, the vegetation installed on sewage sludge in the process of mineralization, composed predominantly of Phragmites, Rumex, Chenopodium, and Aster species had accumulated in roots, stems and leaves Zn quantities equivalent to 1463 mg Kg-1, 3988 mg Kg-1, 1463 mg Kg-1, respectively, 1120 mg∙Kg-1. The plants in question represents the natural means of phytoremediation, and sewage sludge as such may constitute a fertilizer material for soils in the area, on which Zn deficiency in maize has been recorded. In addition, the ash resulted from the incineration of plants loaded with zinc may constitute, in its turn, a good material for fertilizing of the soils that are deficient in zinc.

  11. Anaerobic wastewater treatment of concentrated sewage using a two-stage upflow anaerobic sludge blanket- anaerobic filter system. (United States)

    Halalsheh, Maha M; Abu Rumman, Zainab M; Field, Jim A


    A two-stage pilot-scale upflow anaerobic sludge blanket - anaerobic filter (UASB-AF) reactors system treating concentrated domestic sewage was operated at 23 degrees C and at hydraulic retention times (HRT) of 15 and 4 h, respectively. Excess sludge from the downstream AF stage was returned to the upstream UASB reactor. The aim was to obtain higher sludge retention time (SRT) in the UASB reactor for better methanization of suspended COD. The UASB-AF system removed 55% and 65% of the total COD (COD(tot)) and suspended COD (COD(ss)), respectively. The calculated SRT in the UASB reactor ranged from 20-35 days. The AF reactor removed the washed out sludge from the first stage reactor with average COD(ss) removal efficiency of 55%. The volatile fatty acids concentration in the effluent of the AF was 39 mg COD/L compared with 78 mg COD/L measured for the influent. The slightly higher COD(tot) removal efficiency obtained in this study compared with a single stage UASB reactor was achieved at 17% reduction in the total volume.

  12. Nitrogen mineralisation and greenhouse gas emission from the soil application of sludge from reed bed mineralisation systems

    DEFF Research Database (Denmark)

    Gómez-Muñoz, B; Larsen, Julie Dam; Bekiaris, G


    A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time (stabilisa......A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time...

  13. Characterization and treatment of sludge from the petroleum industry

    African Journals Online (AJOL)

    ... sludge can undergo biodegradation and suggests that biological method could be used in effecting treatment to the sludge. The high conductivity also indicated that the sludge can be treated by physicochemical method of coagulation and flocculation. Keywords: Petroleum sludge, pollution characteristics, eutrophication, ...

  14. An Economic comparison of sludge irradiation and alternative methods of municipal sludge treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstrom, S.B.; McGuire, H.E.


    The relative economics of radiation treatment and other sludge treatment processes are reported. The desirability of radiation treatment is assessed in terms of cost and the quality of the treated sludge product. The major conclusions of this study are: radiation treatment is a high-level disinfection process. Therefore, it should only be considered if high levels of disinfection are required for widespread reuse of the sludge; the handling, transporting and pathogen growback problems associated with disinfected wet sludge makes it less attractive for reuse than dry sludge; radiation of composted sludge produces a product of similar quality at less cost than any thermal treatment and/or flash drying treatment option for situations where a high degree of disinfection is required; and heavy metal concerns, especially cadmium, may limit the reuse of sludge despite high disinfection levels. It is recommended that radiation treatment of sludge, particularly dry sludge, continue to be studied. A sensitivity analysis investigating the optimal conditions under which sludge irradiation operates should be instigated. Furthermore, costs of adding sludge irradiation to existing sludge treatment schemes should be determined.

  15. Assessment of low concentration wastewater treatment operations with dewatered alum sludge-based sequencing batch constructed wetland system


    Kang, Wei; Chai, Hongxiang; Xiang, Yu; Chen, Wei; Shao, Zhiyu; He, Qiang


    Competition of volatile fatty acids between anoxic denitrification and anaerobic phosphorus release is prominent. Therefore, low concentration wastewater has restricted effects on nitrogen and phosphorus removal. The purpose of this study is to treat dormitory sewage with a biochemical oxygen demand (BOD) ranging from 50 to 150 mg/L using dewatered alum sludge-based sequencing batch constructed wetland system. Vegetation in the wetland system was chosen to be Phragmites australis. Three paral...

  16. Recovery of phosphorus from sewerage treatment sludge

    Energy Technology Data Exchange (ETDEWEB)

    Manuilova, Anastasia


    This thesis is a review of the current state of technologies for the removal of phosphorus from wastewater and sludge, and the recovery and re-use of phosphorus. It explains the need for phosphorus removal and describes the current removal processes. Focus is given to phosphorus crystallisation processes and to the processes which treat sewage treatment sludges into potential sources of phosphorus. An interesting possibility to recover phosphorus from sewage sludge by use of Psenner fractionation is also discussed. By this method, the following phosphate fractions of technological significance may be distinguished: (1) redox sensitive phosphates, mainly bound to Fe(OH){sub 3}; (2) phosphate adsorbed to surfaces (Al{sub 2}O{sub 3}), exchangeable against OH{sup -}, and alkali-soluble phosphate; (3) phosphate bound to CaCO{sub 3}, MgCO{sub 3} and in apatite; and (4) organically bound phosphate. The basic removal mechanisms, process schemes and treatment results are described. Two experiments with three different types of sludges from Henriksdal wastewater treatment plant in Stockholm were performed in the laboratory. It was shown that the addition of sodium hydroxide or hydrochloric acid cause the significant release of phosphate (about 80%) for all types of sludges. If a whole Psenner fractionation was performed the phosphate release is approximately 100%.

  17. Sulfamethoxazole degradation in anaerobic sulfate-reducing bacteria sludge system. (United States)

    Jia, Yanyan; Khanal, Samir Kumar; Zhang, Huiqun; Chen, Guang-Hao; Lu, Hui


    Sulfamethoxazole (SMX) is one of the most commonly used antibiotics. SMX degradation in sulfate-reducing bacteria (SRB) sludge systems has not been reported so far. This research investigated the SMX degradation using SRB sludge in a sulfate-reducing up-flow sludge bed reactor. Moreover, the mechanisms and kinetics of SMX removal were also investigated using SRB sludge via a series of batch experiments. The results showed that SMX removal was characterized by a rapid sorption onto SRB sludge, and desorption from SRB sludge to aqueous phase until achieving equilibrium, and then followed by slow biodegradation. Biodegradation was the dominant route for SMX removal. The sorption process conformed well to a pseudo-second-order kinetic model, meaning that the sorption occurred primarily via a chemical sorption process. The removal of SMX followed the pseudo-zero-order kinetic model with a specific removal rate of 13.2 ± 0.1 μg/L/d at initial SMX concentration 100 μg/L in batch tests. Based on the analysis of metabolites, most of the SMX biotransformation products' structures altered in the isoxazole ring, which were significantly different from that produced by aerobic and anaerobic sludge systems. Thus, SRB sludge system could play an important role in SMX biodegradation, especially in Sulfate-reduction Autotrophic denitrification and Nitrification Integrated (SANI) process for sewage treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogen production. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  20. Screw pyrolysis technology for sewage sludge treatment. (United States)

    Tomasi Morgano, Marco; Leibold, Hans; Richter, Frank; Stapf, Dieter; Seifert, Helmut


    Sewage sludge quantities have grown continuously since the introduction of the European Directive (UWWTD 91/271/EEC) relating to the treatment of urban wastewater. In the present, most of the sewage sludge is combusted in single fuels incineration plants or is co-fired in waste incineration or coal power plants. The combustion of sewage sludge is a proven technology. Other treatments, such as fluidized bed gasification, were successfully adopted to produce suitable syngas for power production. Besides, the number of large wastewater treatment plants is relatively small compared to the local rural ones. Moreover, alternative technologies are arising with the main target of nutrients recovery, with a special focus on phosphorus. The aforementioned issues, i.e. the small scale (below 1MW) and the nutrients recovery, suggest that pyrolysis in screw reactors may become an attractive alternative technology for sewage sludge conversion, recovery and recycling. In this work, about 100kg of dried sewage sludge from a plant in Germany were processed at the newly developed STYX Reactor, at KIT. The reactor combines the advantages of screw reactors with the high temperature filtration, in order to produce particle and ash free vapors and condensates, respectively. Experiments were carried out at temperatures between 350°C and 500°C. The yield of the char decreased from 66.7wt.% to 53.0wt.%. The same trend was obtained for the energy yield, while the maximum pyrolysis oil yield of 13.4wt.% was obtained at 500°C. Besides mercury, the metals and the other minerals were completely retained in the char. Nitrogen and sulfur migrated from the solid to the condensate and to the gas, respectively. Based on the energy balance, a new concept for the decentral production of char as well as heat and power in an externally fired micro gas turbine showed a cogeneration efficiency up to about 40%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Priority and emerging pollutants in sewage sludge and fate during sludge treatment. (United States)

    Mailler, R; Gasperi, J; Chebbo, G; Rocher, V


    This paper aims at characterizing the quality of different treated sludges from Paris conurbation in terms of micropollutants and assessing their fate during different sludge treatment processes (STP). To achieve this, a large panel of priority and emerging pollutants (n=117) have been monitored in different STPs from Parisian wastewater treatment plants including anaerobic digestion, thermal drying, centrifugation and a sludge cake production unit. Considering the quality of treated sludges, comparable micropollutant patterns are found for the different sludges investigated (in mg/kg DM - dry matter). 35 compounds were detected in treated sludges. Some compounds (metals, organotins, alkylphenols, DEHP) are found in every kinds of sludge while pesticides or VOCs are never detected. Sludge cake is the most contaminated sludge, resulting from concentration phenomenon during different treatments. As regards treatments, both centrifugation and thermal drying have broadly no important impact on sludge contamination for metals and organic compounds, even if a slight removal seems to be possible with thermal drying for several compounds by abiotic transfers. Three different behaviors can be highlighted in anaerobic digestion: (i) no removal (metals), (ii) removal following dry matter (DM) elimination (organotins and NP) and iii) removal higher than DM (alkylphenols - except NP - BDE 209 and DEHP). Thus, this process allows a clear removal of biodegradable micropollutants which could be potentially significantly improved by increasing DM removal through operational parameters modifications (retention time, temperature, pre-treatment, etc.). Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant. (United States)

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


    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Capital and operating costs of full-scale fecal sludge management and wastewater treatment systems in Dakar, Senegal. (United States)

    Dodane, Pierre-Henri; Mbéguéré, Mbaye; Sow, Ousmane; Strande, Linda


    A financial comparison of a parallel sewer based (SB) system with activated sludge, and a fecal sludge management (FSM) system with onsite septic tanks, collection and transport (C&T) trucks, and drying beds was conducted. The annualized capital for the SB ($42.66 capita(-1) year(-1)) was ten times higher than the FSM ($4.05 capita(-1) year(-1)), the annual operating cost for the SB ($11.98 capita(-1) year(-1)) was 1.5 times higher than the FSM ($7.58 capita(-1) year(-1)), and the combined capital and operating for the SB ($54.64 capita(-1) year(-1)) was five times higher than FSM ($11.63 capita(-1) year(-1)). In Dakar, costs for SB are almost entirely borne by the sanitation utility, with only 6% of the annualized cost borne by users of the system. In addition to costing less overall, FSM operates with a different business model, with costs spread among households, private companies, and the utility. Hence, SB was 40 times more expensive to implement for the utility than FSM. However, the majority of FSM costs are borne at the household level and are inequitable. The results of the study illustrate that in low-income countries, vast improvements in sanitation can be affordable when employing FSM, whereas SB systems are prohibitively expensive.

  4. Capital and Operating Costs of Full-Scale Fecal Sludge Management and Wastewater Treatment Systems in Dakar, Senegal (United States)


    A financial comparison of a parallel sewer based (SB) system with activated sludge, and a fecal sludge management (FSM) system with onsite septic tanks, collection and transport (C&T) trucks, and drying beds was conducted. The annualized capital for the SB ($42.66 capita–1 year–1) was ten times higher than the FSM ($4.05 capita–1 year–1), the annual operating cost for the SB ($11.98 capita–1 year–1) was 1.5 times higher than the FSM ($7.58 capita–1 year–1), and the combined capital and operating for the SB ($54.64 capita–1 year–1) was five times higher than FSM ($11.63 capita–1 year–1). In Dakar, costs for SB are almost entirely borne by the sanitation utility, with only 6% of the annualized cost borne by users of the system. In addition to costing less overall, FSM operates with a different business model, with costs spread among households, private companies, and the utility. Hence, SB was 40 times more expensive to implement for the utility than FSM. However, the majority of FSM costs are borne at the household level and are inequitable. The results of the study illustrate that in low-income countries, vast improvements in sanitation can be affordable when employing FSM, whereas SB systems are prohibitively expensive. PMID:22413875

  5. Microplastics in Sewage Sludge: Effects of Treatment. (United States)

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


    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.

  6. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    Directory of Open Access Journals (Sweden)

    Taina Tervahauta


    Full Text Available This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were compared in terms of biochemical methane potential (BMP, UASB reactor performance, chemical oxygen demand (COD mass balance and methanization. Grey water sludge treatment with black water increased the energy recovery by 23% in the UASB reactor compared to black water treatment. The increase in the energy recovery can cover the increased heat demand of the UASB reactor and the electricity demand of the grey water bioflocculation system with a surplus of 0.7 kWh/cap/y electricity and 14 MJ/cap/y heat. However, grey water sludge introduced more heavy metals in the excess sludge of the UASB reactor and might therefore hinder its soil application.

  7. Effects of wastewater treatment processes on the sludge reduction system with 2,4-dichlorophenol: Sequencing batch reactor and anaerobic-anoxic-oxic process. (United States)

    Han, Yunping; Sun, Yongli; Chen, Hong; Guo, Xuesong; Yu, Chuanyang; Li, YanBo; Liu, Junxin; Xiao, Benyi


    The effects of two wastewater treatment processes (sequencing batch reactor, SBR; and anaerobic-anoxic-oxic, A2O) on sludge reduction with metabolic uncoupler 2,4-dichlorophenol (DCP) were studied in laboratory. The experimental results showed that the reduction of cumulative excess sludge in SBR and A2O was 43.7% and 44.2%, respectively, during the stable stage of the test. The two processes had similar average sludge yield and sludge yield reduction, i.e., 0.306 and 0.305mg of SS/mg chemical oxygen demand (COD), and 16.9% and 17.8%, respectively. The effect of DCP on the wastewater treatment efficiencies (namely, removal of COD, total nitrogen, NH4+-N, and total phosphorus) of the two processes were also similar. SBR was more likely to slightly retard the increase of activated sludge SVI with lesser increase in extracellular polymeric substances and protein/polysaccharide ratio. Although DCP did not dramatically affect the microbial communities of sludge, SBR was more favorable for increasing the activated sludge SOUR and maintaining the primary microorganisms of sludge than A2O. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    M. Orikawa


    Full Text Available Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS dewatered sludge. The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic carbon (POC and dissolved organic carbon (DOC. The hydrothermal treatment was investigated under 10-60 min of treatment time, 180-200 °C of temperature, 10-22 %-TS of sewage sludge concentration. The results showed that the DOC in each conditions increased through hydrothermal treatment. The highest DOC obtained was 67 % of total carbon concentration, when the temperature was 180 °C, treatment time was 60 min and sewage sludge concentration was 10 %-TS. Furthermore, the viscosity of treated sewage sludge was decreased by hydrothermal treatment. In batch anaerobic digestion test, methane gas production was confirmed. In addition, this study evaluated the energy balance of this system. Thus, the results of this study indicated that the possibility of application of hydrothermal treatment to high concentrated sewage sludge for anaerobic digestion process. Keywords: anaerobic reaction, hydrothermal treatment, sewage sludge, solubilization

  9. Pre-treatment of tannery sludge for sustainable landfilling. (United States)

    Alibardi, Luca; Cossu, Raffaello


    The wastewater produced during tanning activities are commonly conveyed to centralised industrial wastewater treatment plants. Sludge from physical-chemical treatments (i.e. primary sedimentation) and waste activated sludge from biological treatment units are called tannery sludge. Tannery sludge is a solid waste that needs to be carefully managed and its disposal represents one of the major problems in tannery industry. Conventional treatment and disposal of tannery sludge are based mainly on incineration and landfilling. The aim of this study was to evaluate the effects of a pre-treatment process composed of aerobic stabilisation, compaction and drying, for a sustainable landfilling of tannery sludge. The process produced a reduction of volume, mass and biodegradability of treated sludge. Results also demonstrated a reduced leachability of organic and inorganic compounds from treated sludge. The pre-treatment process could allow to extend landfill life time due to lower amounts of tannery sludge to be disposed off, minimise long terms landfill emissions and obtain a state of carbon sink for tannery sludge landfilling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Enhanced treatment of Fischer-Tropsch (F-T) wastewater using the up-flow anaerobic sludge blanket coupled with bioelectrochemical system: Effect of electric field. (United States)

    Wang, Dexin; Han, Hongjun; Han, Yuxing; Li, Kun; Zhu, Hao


    The coupling of bioelectrochemical system (BES) with an up-flow anaerobic sludge blanket (UASB) was established for enhanced Fischer-Tropsch (F-T) wastewater treatment while the UASB (control group) was operated in parallel. The presence of electric field could offer system a more reductive micro-environment that lower the ORP values and maintain the appropriate pH range, resulting in the higher chemical oxygen demand (COD) removal efficiency and methane production for BES-UASB (86.8% and 2.31±0.1L/(L·d)) while those values in control group were 72.1% and 1.77±0.08L/(L·d). In addition, the coupled system could promote sludge granulation to perform a positive effect on maintaining stability of pollutants removal. The high-throughput 16S rRNA gene pyrosequencing in this study further confirmed that the promoting direct interspecies electron transfer (DIET) between Geobacter and Methanosarcina might be established in BES-UASB to improve the syntrophic degradation of propionate and butyrate, finally facilitated completely methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.


    Energy Technology Data Exchange (ETDEWEB)



    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

  12. [Pollution characteristics of heavy metals in sludge from wastewater treatment plants and sludge disposal in Chinese coastal areas]. (United States)

    Zhang, Can; Chen, Hong; Yu, Yi-Xuan; Wang, Li-Jun; Han, Jian-Bo; Tao, Ping


    Thirteen sludge samples from Guangzhou, Shanghai and Dalian were collected and analysed for heavy metals to investigate the distribution and variation trend of heavy metals in sludge from wastewater treatment plants in Chinese coastal areas. The results showed that contents of heavy metals in sludge varied significantly, and the average contents exhibited an order of Cr > Zn > Cu > Pb > As > Hg > Cd. Additionally, contents of Cr, Cu and As exceeded their corresponding standard levels. Compared with contents of heavy metals in 2006 and 2001, content of Zn in sludge increased while contents of Cr, Cu and As decreased. Results also indicated that the industrial sludge was more seriously polluted than domestic sludge in terms of Zn, Cu and As. Only 23% sludge samples exceeded the standards for fertilization of sludge, suggesting that most of the sludge could be disposed by land application. These results also provide further information about the establishment of ocean disposal assessment for sludge.

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

    NARCIS (Netherlands)

    Basim, Y.; Farzadkia, M.; Jaafarzadeh, N.; Hendrickx, T.L.G.


    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

  14. Impact of secondary treatment types and sludge handling processes on estrogen concentration in wastewater sludge. (United States)

    Marti, Erica J; Batista, Jacimaria R


    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

  15. Heavy metal sequestration by humic substances during phyto-treatment of sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzi, E.; Doni, S.; Macci, C.; Ceccanti, B.; Masciandaro, G.


    The presence of heavy metals in sludges stabilized in a reed bed system, may affect their use for agricultural purposes; however, the environmental impact of sludges depends on the availability and phyto toxicity of their heavy metal. The aim of this paper was to determine the effectiveness of a reed bed (Phragmites Australia) sludge treatment system in two urban wastewater treatment plants in Italy after two-year period of operation: by estimating the process of sludge stabilization, following conventional and non conventional parameters related with the evolution of organic matter quality (Water soluble Carbon, Dehydrogenase activity, Fulvic Acids, Humic Acids, Pyrolytic indices or organic matter Mineralization and Humification); by following the heavy metal speciation bioavailability in sludges. (Author)

  16. Cultivation of aerobic granular sludge for rubber wastewater treatment. (United States)

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


    Aerobic granular sludge (AGS) was successfully cultivated at 27±1 °C and pH 7.0±1 during the treatment of rubber wastewater using a sequential batch reactor system mode with complete cycle time of 3 h. Results showed aerobic granular sludge had an excellent settling ability and exhibited exceptional performance in the organics and nutrients removal from rubber wastewater. Regular, dense and fast settling granule (average diameter, 1.5 mm; settling velocity, 33 m h(-1); and sludge volume index, 22.3 mL g(-1)) were developed in a single reactor. In addition, 96.5% COD removal efficiency was observed in the system at the end of the granulation period, while its ammonia and total nitrogen removal efficiencies were up to 94.7% and 89.4%, respectively. The study demonstrated the capabilities of AGS development in a single, high and slender column type-bioreactor for the treatment of rubber wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Relationship between enhanced dewaterability and structural properties of hydrothermal sludge after hydrothermal treatment of excess sludge. (United States)

    Wang, Liping; Li, Aimin; Chang, Yuzhi


    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Performance indicators and indices of sludge management in urban wastewater treatment plants. (United States)

    Silva, C; Saldanha Matos, J; Rosa, M J


    Sludge (or biosolids) management is highly complex and has a significant cost associated with the biosolids disposal, as well as with the energy and flocculant consumption in the sludge processing units. The sludge management performance indicators (PIs) and indices (PXs) are thus core measures of the performance assessment system developed for urban wastewater treatment plants (WWTPs). The key PIs proposed cover the sludge unit production and dry solids concentration (DS), disposal/beneficial use, quality compliance for agricultural use and costs, whereas the complementary PIs assess the plant reliability and the chemical reagents' use. A key PI was also developed for assessing the phosphorus reclamation, namely through the beneficial use of the biosolids and the reclaimed water in agriculture. The results of a field study with 17 Portuguese urban WWTPs in a 5-year period were used to derive the PI reference values which are neither inherent to the PI formulation nor literature-based. Clusters by sludge type (primary, activated, trickling filter and mixed sludge) and by digestion and dewatering processes were analysed and the reference values for sludge production and dry solids were proposed for two clusters: activated sludge or biofilter WWTPs with primary sedimentation, sludge anaerobic digestion and centrifuge dewatering; activated sludge WWTPs without primary sedimentation and anaerobic digestion and with centrifuge dewatering. The key PXs are computed for the DS after each processing unit and the complementary PXs for the energy consumption and the operating conditions DS-determining. The PX reference values are treatment specific and literature based. The PI and PX system was applied to a WWTP and the results demonstrate that it diagnosis the situation and indicates opportunities and measures for improving the WWTP performance in sludge management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor. (United States)

    Ge, Huoqing; Batstone, Damien; Keller, Jurg


    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.

  20. The Treatment of Sludge from the Rubber Processing Industry with ...

    African Journals Online (AJOL)

    ... readily available, cheap and easy to handle, more biodegradable, therefore more environmentally friendly. The use of the coagulant for the treatment of sludge and indeed where coagulation and flocculation is desirous can be so recommended. Keywords: Biodegradable, Chitosan, Exoskeleton, Pollution, Sludge,.

  1. Recent advances in membrane bio-technologies for sludge reduction and treatment. (United States)

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


    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Multi-scale modelling of bioreactor–separator system for wastewater treatment with two-dimensional activated sludge floc dynamics

    NARCIS (Netherlands)

    Ofi?eru, I.D.; Bellucci, M.; Picioreanu, C.; Lavric, V.; Curtis, T.P.


    A simple “first generation” multi-scale computational model of the formation of activated sludge flocs at micro-scale and reactor performance at macro-scale is proposed. The model couples mass balances for substrates and biomass at reactor scale with an individual-based approach for the floc

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

    Energy Technology Data Exchange (ETDEWEB)



    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.

  4. An environmental LCA of alternative scenarios of urban sewage sludge treatment and disposal

    Directory of Open Access Journals (Sweden)

    Tarantini Mario


    Full Text Available The majority of pollutants that affect wastewater are concentrated by treatment processes in sludge; it is therefore critical to have a suitable evaluation methodology of sludge management options to analyze if pollution is redirected from water to other media, such as air and soil. Life cycle assessment is one of the most widely known and internationally accepted methodologies to compare environmental impacts of processes and systems and to evaluate their sustainability in the entire life cycle. In this study the methodology was applied to assess and compare three scenarios of urban sewage sludge treatment and disposal: sludge anaerobic digestion followed by dedicated incineration, sludge incineration without previous digestion, and sludge anaerobic digestion followed by composting. The potential benefits of spreading the compost to soil were not included in the system boundaries even if, due to its nutrients contents and soil improving features, compost could partially replace the use of commercial products. The study was aimed at finding out the environmental critical points of the treatment alternatives selected and at providing a technical and scientific contribution for further debates with national and local authorities on the environmental optimization of sewage sludge management. Life cycle assessment results confirmed the major contribution of electricity and methane consumption on several environmental impact categories. Incineration contributes more than sludge composting to almost all categories, although the heavy metals content of urban wastewater sludge raises substantial concerns when composted sludge is spread to soil. In this paper the models adopted, the hypotheses assumed and the main findings of the study are presented and discussed. .

  5. Application of waterworks sludge in wastewater treatment plants

    DEFF Research Database (Denmark)

    Sharma, Anitha Kumari; Thornberg, D.; Andersen, Henrik Rasmus


    The potential for reuse of iron-rich sludge from waterworks as a replacement for commercial iron salts in wastewater treatment was investigated using acidic and anaerobic dissolution. The acidic dissolution of waterworks sludge both in sulphuric acid and acidic products such as flue gas washing...... for removal of phosphate in the wastewater treatment was limited, because the dissolved iron in the digester liquid was limited by siderite (FeCO3) precipitation. It is concluded that both acidic and anaerobic dissolution of iron-rich waterworks sludge can be achieved at the wastewater treatment plant...

  6. Evaluation of Baffle Fixes Film up Flow Sludge Blanket Filtration (BFUSBF System in Treatment of Wastewaters from Phenol and 2,4-Dinitrophenol Using Daphnia Magna Bioassay

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Ghannadzadeh


    Full Text Available Background: Phenol and nitrophenol are common compounds found in different types of industrial wastewater known as serious threats to human health and natural environment. In this study, Daphnia magna was used to evaluate the effectiveness of "baffle fixes film up flow sludge blanket filtration" (BFUSBF system in elimination of phenolic compounds from water. Methods: D. magna cultures were used as toxicity index of phenol and 2,4-DNP mixtures after treatment by a pilot BFUSBF system which consisted of baffle in anoxic section and biofilm in aerobic sections. Initial concentrations were 312 mg/L phenol and 288 mg/L 2,4-dinitrophenol (2,4-DNP. Results: Bioassay tests showed that D. magna was influenced by the toxicity of phenol and 2,4 DNP mixtures. The comparison between the toxicity of initial phenol and 2,4-DNP mixtures and the output toxic unit (TU derived from BFUSBF treatment system showed that the TU of the effluent from BFUSBF reactor was much lower than that of the solution that entered the reactor. Conclusion: Based on the acute toxicity test, BFUSBF process could reduce phenol and 2,4-DNP in aqueous solutions. Therefore, it is possible to use BFUSBF process as an appropriate treatment option for wastewaters containing phenolic compounds.

  7. The challenge of faecal sludge management in urban areas--strategies, regulations and treatment options. (United States)

    Ingallinella, A M; Sanguinetti, G; Koottatep, T; Montanger, A; Strauss, M


    In urban centres of industrialising countries, the majority of houses are served by on-site sanitation systems such as septic tanks and unsewered toilets. The faecal sludges (FS) collected from these systems are usually discharged untreated into the urban and peri-urban environment, posing great risks to water resources and to public health. Contrary to wastewater management, the development of strategies to cope with faecal sludges, adapted to the conditions prevailing in developing countries, have long been neglected. The authors describe the current situation and discuss selected issues of FS management. A proposal is made for a rational setting of sludge quality or treatment standards in economically emerging countries. The authors stipulate that regulatory setting should take into account local economic, institutional and technical conditions. Defining suitable treatment options as critical control points in securing adequate sludge quality is better than setting and relying on numerical sludge quality standards. A separate section is devoted to the practice and to regulatory aspects of (faecal) sludge use in Argentina. An overview of treatment options, which may prove sustainable in less industrialized countries is provided. Planted sludge drying beds are one of these options. It has been piloted in Thailand for four years and details on its performance and operation are presented along with data on the hygienic quality of treated biosolids.

  8. Sludge. (United States)

    Tenenbaum, David


    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)

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Comparison of bacterial communities of conventional and A-stage activated sludge systems

    NARCIS (Netherlands)

    Gonzalez-Martinez, A.; Rodriguez-Sanchez, A.; Lotti, T.; Garcia-Ruiz, M.J.; Gonzalez-Lopez, J.; Van Loosdrecht, M.C.M.


    The bacterial community structure of 10 different wastewater treatment systems and their influents has been investigated through pyrosequencing, yielding a total of 283486 reads. These bioreactors had different technological configurations: conventional activated sludge (CAS) systems and very highly

  11. Modelling of Activated Sludge Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Kurtanjeka, Ž.


    Full Text Available Activated sludge wastewater treatment is a highly complex physical, chemical and biological process, and variations in wastewater flow rate and its composition, combined with time-varying reactions in a mixed culture of microorganisms, make this process non-linear and unsteady. The efficiency of the process is established by measuring the quantities that indicate quality of the treated wastewater, but they can only be determined at the end of the process, which is when the water has already been processed and is at the outlet of the plant and released into the environment.If the water quality is not acceptable, it is already too late for its improvement, which indicates the need for a feed forward process control based on a mathematical model. Since there is no possibility of retracing the process steps back, all the mistakes in the control of the process could induce an ecological disaster of a smaller or bigger extent. Therefore, models that describe this process well may be used as a basis for monitoring and optimal control of the process development. This work analyzes the process of biological treatment of wastewater in the Velika Gorica plant. Two empirical models for the description of the process were established, multiple linear regression model (MLR with 16 predictor variables and piecewise linear regression model (PLR with 17 predictor variables. These models were developed with the aim to predict COD value of the effluent wastewater at the outlet, after treatment. The development of the models is based on the statistical analysis of experimental data, which are used to determine the relations among individual variables. In this work are applied linear models based on multiple linear regression (MLR and partial least squares (PLR methods. The used data were obtained by everyday measurements of the quantities that indicate the quality of the input and output water, working conditions of the plant and the quality of the activated sludge

  12. Investigation of the bio pile treatment for oily sludge (United States)

    Bai, He; Wang, Xinxin; Chen, Yu; Cao, Xingtao; Ma, Zhengzhao; Guo, Bing; Zhao, Guangyu; Li, Chen


    With the rapid development of petro-chemical industry as well as the stricter requirement of environmental protection, the treatment of oily sludge is around the corner for the petroleum companies. A pilot experiment had been carried out in this study to investigate the changes of n-alkanes, polycyclic aromatic hydrocarbons and total petroleum hydrocarbons in the oily sludge. Results show that the oil content in the sludge decreased to 5023 mg/kg within 90 days, which provide technical support for the engineering application of bio pile treatment

  13. Ultrasonic reduction of excess sludge from activated sludge system: energy efficiency improvement via operation optimization. (United States)

    He, Junguo; Wan, Tian; Zhang, Guangming; Yang, Jing


    This paper studied the influences of operational parameters to improve the energy efficiency during 'ultrasonic lysis-cryptic growth' sludge reduction. Subsequent batch reactor with a hydraulic retention time of 8 h was used to treat urban sewage, and ultrasound wave with a specific energy of 20 kWh/kg TS was employed for sludge lysis. A new index, EE, was defined to evaluate the energy efficiency in ultrasonic lysis-cryptic growth sludge reduction system. Results showed that the most important operational parameter was the proportion of sonicated sludge (SP), which determined the energy consumption and significantly impacted the energy efficiency. The upper limit of SP in this study was 30%, beyond which the effluent quality was unacceptable. Higher SP caused heavier sludge reduction but more energy consumption; when SP was 30%, the excess sludge reduction was the greatest (67.6%) and the energy consumption was the highest (0.101 kWh/d). With a given SP, frequent sludge lysis was adverse to sludge reduction. In summary, the recommended conditions for 'ultrasonic lysis-cryptic growth' sludge reduction were SP of 15%, lysis frequency of 1 time/day. Under these conditions, the highest energy efficiency of 0.012 kg TS/kWh was achieved. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Performance evaluation of the pilot scale upflow anaerobic sludge blanket - Downflow hanging sponge system for natural rubber processing wastewater treatment in South Vietnam. (United States)

    Watari, Takahiro; Mai, Trung Cuong; Tanikawa, Daisuke; Hirakata, Yuga; Hatamoto, Masashi; Syutsubo, Kazuaki; Fukuda, Masao; Nguyen, Ngoc Bich; Yamaguchi, Takashi


    A pilot-scale upflow anaerobic sludge blanket (UASB)-downflow hanging sponge system (DHS) combined with an anaerobic baffled reactor (ABR) and a settling tank (ST) was installed in a natural rubber processing factory in South Vietnam and its process performance was evaluated for 267days. The UASB reactor achieved a total removal efficiency of 55.6±16.6% for chemical oxygen demand (COD) and 77.8±10.3% for biochemical oxygen demand (BOD) with an organic loading rate of 1.7±0.6kg-COD·m-3·day-1. The final effluent of the proposed system had 140±64mg·L-1 of total COD, 31±12mg·L-1 of total BOD, and 58±24mg-N·L-1 of total nitrogen. The system could significantly reduce 92% of greenhouse gas emissions and 80% of hydraulic retention times compared with current treatment systems. Copyright © 2017. Published by Elsevier Ltd.

  15. Thermoradiation treatment of sewage sludge using reactor waste fission products

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M. C.; Hagengruber, R. L.; Zuppero, A. C.


    The hazards to public health associated with the application of municipal sewage sludge to land usage are reviewed to establish the need for disinfection of sludge prior to its distribution as a fertilizer, especially in the production of food and fodder. The use of ionizing radiation in conjunction with mild heating is shown to be an effective disinfection treatment and an economical one when reactor waste fission products are utilized. A program for researching and experimental demonstration of the process on sludges is also outlined.

  16. Analysis of lagoon sludge characteristics for choice of treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. H.; Hwang, D. S.; Choi, Y. D.; Lee, K. I.; Hwang, S. T.; Jung, K. J. [Korea Atomic Energy Research Institute, Taejeon (Korea)


    The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and impurities of the yellow cake. The content of uranium, thorium and Ra-226 was high in pond-1 and low in pond-2 because those were removed during Ca precipitation. On the base of the characteristics of the sludge and available technologies, reviewed in this study and being developed in Korea Atomic Energy Research Institute, two processes were proposed and evaluated in points of the expected technological difficulties. And the cost for treatment of sludges are estimated for both processes. 79 refs., 44 figs., 37 tabs. (Author)

  17. Examining sludge production in bioelectrochemical systems treating domestic wastewater. (United States)

    Brown, Robert Keith; Harnisch, Falk; Dockhorn, Thomas; Schröder, Uwe


    Sludge production in microbial bioelectrochemical systems (BES) was assessed in conjunction with anaerobic and aerobic control reactors. Effluent after primary settling tank (EAPS) and depleted EAPS spiked with acetate were treated. The reactors were loaded with total suspended solids (TSS) and chemical oxygen demand (COD) at average loading rates of 22 mg TSS d(-1)L(-1) and 86 mg COD d(-1)L(-1), respectively. Carbon cloth anode equipped BES reactors delivered the highest performance. They achieved on average a COD removal of 80%, a Coulomb efficiency of 77% for EAPS, a maximum current density of 39 μA cm(-)(3)/175 μA cm(-)(2) for EAPS and a TSS removal of 59%, yielding a sludge production of only 80 mg TSS per g ΔCOD. This study provides further evidence that BES can improve the economics of wastewater treatment via lower sludge production as well as providing a framework for understanding sludge production in BES. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Luciano Piani


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

  19. Life cycle assessment of sewage sludge treatment and its use on land

    DEFF Research Database (Denmark)

    Yoshida, Hiroko

    - ) into the environment were major contributors to almost all of the non-toxic impact categories. Hence, a depiction of the N balance through the target systems, beyond energy and C balance, often included in environmental assessments is vital for accurately evaluating the environmental performance of sewage sludge......Sewage sludge is generated as an end-product of wastewater treatment processes, and its management holds importance in the operation of wastewater treatment plants from both an economic and an environmental point of view. At the same time, the management of sewage sludge is becoming increasingly...... multi-focused, as renewable energy and nutrient recovery have been added to the list beyond sanitation and stabilisation of sewage sludge. In order to organise and quantify environmental benefits and associated burdens, in order to facilitate an informed decision making process, life cycle assessments...

  20. Development and application of real-time PCR for quantification of specific ammonia-oxidizing bacteria in activated sludge of sewage treatment systems. (United States)

    Limpiyakorn, Tawan; Kurisu, Futoshi; Yagi, Osami


    In this study, four real-time polymerase chain reaction (PCR) primer sets were developed for the 16S rRNA genes of specific ammonia-oxidizing bacteria (AOB) found in activated sludge of sewage treatment systems. The primer sets target two of several sequence types of the Nitrosomonas oligotropha cluster, members within the Nitrosomonas communis cluster, and all members of the Nitrosomonas europaea-Nitrosococcus mobilis cluster. The detection limit of each primer set was in the range of 3x10(1)-6x10(2) genes reaction(-1). Reliable quantification of the target AOB DNA was obtained when the target AOB DNA comprised more than 0.1% of total AOB DNA in the sample. The application of the primer sets to samples taken from five sewage treatment systems showed that, in all systems, the majority of the AOB population was comprised of one sequence type of the N. oligotropha cluster (3.9+/-1.5x10(9)-1.7+/-0.5x10(10) cell l(-1)) and, in most systems, followed by members within the N. communis cluster (2.8+/-0.3x10(9)-1.0+/-0.1x10(10) cell l(-1)) or/and another sequence type of the N. oligotropha cluster (1.5+/-0.6x10(8)-5.5+/-0.5x10(8) cell l(-1)). N. europaea-N. mobilis cluster arose solely in small numbers (4.9+/-0.8x10(8) cell l(-1)) in one system. Real-time PCR-amplified products obtained from genomic DNA extracted from samples were verified using clone library, and it revealed that only the target AOB DNA were PCR amplified, without amplification of the nontarget sequences.

  1. Treatment of slaughterhouse wastewater in an upflow anaerobic sludge blanket reactor: Sludge characteristics


    Mohammad Mehdi Amin; Nasim Rafiei; Ensiyeh Taheri


    Aims: Present study was done by using upflow anaerobic sludge blanket (UASB) reactor to investigate the effect of influent chemical oxygen demand (COD) and organic load rate on the formation of anaerobic granules in wastewater treatment. Martials and Methods: Upflow anaerobic sludge blanket reactor with working volume 30 L was studied using actual slaughterhouse wastewater at a hydraulic retention time of 1.24 d and at temperatures in the range of 35°C ± 0.5°C for 320 days. The inoculum wa...

  2. Enhanced treatment of Fischer-Tropsch wastewater using up-flow anaerobic sludge blanket system coupled with micro-electrolysis cell: A pilot scale study. (United States)

    Wang, Dexin; Han, Yuxing; Han, Hongjun; Li, Kun; Xu, Chunyan


    The coupling of micro-electrolysis cell (MEC) with an up-flow anaerobic sludge blanket (UASB) system in pilot scale was established for enhanced treatment of Fischer-Tropsch (F-T) wastewater. The lowest influent pH (4.99±0.10) and reduced alkali addition were accomplished under the assistance of anaerobic effluent recycling of 200% (stage 5). Simultaneously, the optimum COD removal efficiency (93.5±1.6%) and methane production (2.01±0.13m3/m3·d) at the lower hydraulic retention time (HRT) were achieved in this stage. In addition, the dissolved iron from MEC could significantly increase the protein content of tightly bound extracellular polymeric substances (TB-EPS), which was beneficial to formation of stable granules. Furthermore, the high-throughput 16S rRNA gene pyrosequencing in this study further confirmed that Geobacter species could utilize iron oxides particles as electron conduit to perform the direct interspecies electron transfer (DIET) with Methanothrix, finally facilitating the syntrophic degradation of propionic acid and butyric acid and contributing completely methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds. (United States)

    Troesch, S; Liénard, A; Molle, P; Merlin, G; Esser, D


    French legislation requires the control of private on-site sanitation systems by local authorities. This will result in a large increase of the quantity of sludge from septic tanks to be treated. Nevertheless, large wastewater treatment plants are not systematically able to treat this sludge because they may have reached their nominal load or they are not so numerous in rural zone to avoid too long transportation. The study concerns both the feasibility of sludge reed beds devoted to the treatment of septage and the assessment of a simultaneous treatment with aerated sludge. The experiments have been carried out on eight pilot-scale drying reed beds (2 m(2)) planted with Phragmites australis. Two filtration layers of either vegetal compost or sand were tested. The study is focused on the commissioning period (first vegetative year) with a loading rate of 30 kg SS m(-2) yr(-1). According to these operational conditions, dewatering efficiencies reached approx. 30% DM during summer but less than 20% DM in winter for each filtration layer and sludge. High removal efficiencies, with an average of 96%, 92% and 89% for SS, COD and TKN respectively, were achieved with septage whereas they were lower for the mixture of aerated sludge and septage. The dewaterability of septage and its filtration behaviour were assessed by several parameters (Capillary Suction Time, bound water) which may be some interesting tools for an optimised loading strategy.

  4. Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic–Anoxic–Aerobic Activated Sludge System (United States)

    Zeng, Qingling; Li, Yongmei; Yang, Shijia


    Abstract Estrogen in wastewater are responsible for a significant part of the endocrine-disrupting effects observed in the aquatic environment. The effect of sludge retention time (SRT) on the removal and fate of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic–anoxic–oxic activated sludge system designed for nutrient removal was investigated by laboratory-scale experiments using synthetic wastewater. With a hydraulic retention time of 8 h, when SRT ranged 10–25 days, E2 was almost completely removed from water, and EE2 removal efficiency was 65%–81%. Both estrogens were easily sorbed onto activated sludge. Distribution coefficients (Kd) of estrogens on anaerobic sludge were greater than those on anoxic and aerobic sludges. Mass balance calculation indicated that 99% of influent E2 was degraded by the activated sludge process, and 1% remained in excess sludge; of influent EE2, 62.0%–80.1% was biodegraded; 18.9%–34.7% was released in effluent; and 0.88%–3.31% remained in excess sludge. Optimal SRT was 20 days for both estrogen and nutrient removal. E2 was almost completely degraded, and EE2 was only partly degraded in the activated sludge process. Residual estrogen on excess sludge must be considered in the sludge treatment and disposal processes. The originality of the work is that removal of nutrients and estrogens were linked, and optimal SRT for both estrogen and nutrient removal in an enhanced biological phosphorus removal system was determined. This has an important implication for the design and operation of full-scale wastewater treatment plants. PMID:23633892

  5. Performance of Wastewater Treatment Plants in Gaza Strip Potential use of Wastewater and Sludge in Agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Shomar, B.H.; Mueller, G.; Yahya, A.


    Twelve elements (Ag, Al, As, Cd, Ca, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were analyzed in 120 composite samples of influent and effluent wastewater; the results revealed that domestic wastewater influent contains considerable amounts of heavy metals and the partially functional treatment plants of Gaza are able to remove 40-70% of most metals during the treatment process. Heavy metals in 31 industrial wastewater effluents are within the ranges of international standards. All industries of Gaza are light, despite that they have no treatment facilities, their effluents are being discharged to municipal sewerage system and the existing treatment plants are capable to absorb the industrial effluents with no significant impact on treatment bioprocesses. Thirty parameters were determined in 35 sludge samples; P, AOX, C, S, CaCO{sub 3}, Mg, Ca, Na, K, Li, Cu, Zn, Ni, Pb, Mn, Fe, Cr, Co, Cd, As, Hg, Ti, Se, Br, Rb, Th, Sr, Y, U, and Zr. Although there are no treatment facilities for sludge within the treatment plants, the results indicated that sludge in general is clean of heavy metals. Zinc and AOX only showed anomalous concentrations; more than 85% of sludge samples showed that averages of zinc and AOX are 2000 mg/kg and 550 mg Cl/kg, respectively, which exceed the standards of all industrial countries for sludge to be used in land application. (author)

  6. Processes for thermal treatment of sewage sludge; Verfahren zur thermischen Klaerschlammverwertung

    Energy Technology Data Exchange (ETDEWEB)

    Boerner, Rolf; Mocker, Mario; Rundel, Paul Michael; Binder, Samir [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany)


    In Germany about two million tons of sewage sludge dry mass arise from wastewater treatment in municipal sewage plants. At present already more than fifty percentage of this quantity is utilized thermally. The thermal treatment takes place in large scale plants predominantly, amongst others about 48 % by co-incineration in coal fired power plants. Furthermore sewage sludge is co-fired in cement plants and waste incineration plants. In case of large scale mono incineration of sewage sludge the stationary fluidized bed firing system is state of the art. In recent years also thermal processes for local treatment of sewage sludge were developed and offered at markets at a progressive rate. In addition to the mainly used incineration processes with grate fired furnaces and fluidized bed system there are several developments in the area of gasification and pyrolysis. At the technical centre for combustion engineering, installed at the ATZ Entwicklungszentrum, detailed analyses regarding the incineration properties and the emission behaviour of sewage sludge were carried out with a new developed vortex firebox and with a modified grate furnace. The results of these combustion tests show, that the specific fuel characteristics of sewage sludge require special technical measures in order to realise a stable incineration. This concern for both firing systems amongst others the pulsing of the fuel feeding, a selective supply and distribution of the combustion air as well as a variable fuel movement. Because the influencing potential regarding the contaminant content of the flue gas by firing measures is limited, in plants for thermal treatment of sewage sludge an aligned flue gas cleaning system is required to meet the emission limits of the 17. BImSchV. (orig.)

  7. Treatment of pulp mill sludges by supercritical water oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Modell, M.


    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.

  8. The final treatment of FGD-waste water sludge

    Energy Technology Data Exchange (ETDEWEB)

    Brugghen, F.W. van der (N.V. KEMA, Arnhem (Netherlands))


    FGD installations based on lime/limestone gypsum processes produce waste water. This waste water has to be treated prior to discharge. The sludge formed during this waste water treatment contains gypsum, CaF[sub 2], Al[sub 2]O[sub 3], SiO[sub 2], Fe[sub 2]O[sub 3] and MgO as well as minor amounts of heavy metals like As, Cd, Pb, Zn and Hg. There are three methods for the final treatment of the sludges: disposal; mixing with gypsum; coffering in the boiler. An inventory has been made of the amounts and composition of the sludge produced by FGD plants in The Netherlands. The consequences of the three treatment methods for emissions, by-product quality and costs are described and compared. 1 ref., 2 figs., 7 tabs.

  9. Bioavailable and biodegradable dissolved organic nitrogen in activated sludge and trickling filter wastewater treatment plants (United States)

    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...

  10. Research on Treatment Technology and Device of Oily Sludge (United States)

    Wang, J. Q.; Shui, F. S.; Li, Q. F.


    Oily sludge is a solid oily waste, which is produced during the process of oil exploitation, transportation, refining and treatment of oily sewage. It contains a great number of hazardous substance, and is difficult to handle with. To solve the problem of waste resources of oil sludge with high oil content and usually not easy to aggregate during the preparation of profile control agent, a new oily sludge treatment device was developed. This device consists of heat supply unit, flush and filter unit, oil removal unit and dehydration unit. It can effectively clean and filter out the waste from oily sludge, recycle the oil resources and reduce the water content of the residue. In the process of operation, the water and chemical agent are recycled in the device, eventually producing little sewage. The device is small, easy to move and has high degree of automation control. The experimental application shows that the oil removal rate of the oily sludge is up to 70%, and the higher the oil content rate the better the treatment.

  11. Technical, economic and environmental assessment of sludge treatment wetlands. (United States)

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


    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 (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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. The sustainable utilization of malting industry wastewater biological treatment sludge (United States)

    Vasilenko, T. A.; Svintsov, A. V.; Chernysh, I. V.


    The article deals with the research of using the sludge from malting industry wastewater’s biological treatment and the calcium carbonate slurry as organo-mineral fertilizing additives. The sludge, generated as a result of industrial wastewater biological treatment, is subject to dumping at solid domestic waste landfills, which has a negative impact on the environment, though its properties and composition allow using it as an organic fertilizer. The physical and chemical properties of both wastes have been studied; the recommendations concerning the optimum composition of soil mix, containing the above-mentioned components, have been provided. The phytotoxic effect on the germination capacity and sprouts of cress (Lepidium sativum), barley (Hordéum vulgáre) and oats (Avena sativa) in soil mixes has been determined. The heavy metals and arsenic contents in the sludge does not exceed the allowable level; it is also free of pathogenic flora and helminthes.

  13. Solar-thermic sewage sludge treatment in extreme alpine environments. (United States)

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


    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.

  14. Characterization of water treatment sludge and its reuse as coagulant. (United States)

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


    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Organic matter and heavy metals content modeling in sewage sludge treated with reed bed system (United States)

    Boruszko, Dariusz; Dąbrowski, Wojciech; Malinowski, Paweł


    The long process of sludge stabilization (7-15 years) remarkably reduces the organic matter content and causes the process of sludge humifaction. This paper presents the results of using low-cost methods of sludge treatment in the wastewater treatment plant located in Zambrow, Podlaskie Province. The results of studies on the organic matter and heavy metals content in sewage sludge after treatment in a reed bed system are presented. The aim of the research was to evaluate and model organic matter and heavy metals concentrations during sewage stabilization in reed bed lagoons. The lowest concentration, below 1.3 mg/kg DM of the examined seven heavy metals was mercury (Hg). The highest concentration, exceeding 1300 mg/kg DM was zinc (Zn). The obtained results for the heavy metals in sewage sludge from the reed bed lagoons in Zambrow show that the average content of the analyzed heavy metals is approximately 1620 mg/kg DM. The results of the study demonstrate a high efficiency of low-cost methods used in Zambrów WWTP in terms of the quality of the processed sludge. Sewage sludge from the lowest layer of the reed lagoon (12-14 years of dewatering and transformation) is characterized by the lowest organic matter and heavy metals content. The higher a sediment layer lies, i.e. the shorter the time of processing, the higher is the heavy metals content. This indicates a great role of reeds in the accumulation of these compounds.

  16. Bioproducts for Sludge Reduction in Activated Sludge Systems Treating Oil Refinery Wastewater

    Directory of Open Access Journals (Sweden)

    Alexandre V.M.F.


    Full Text Available The use of bioproducts that change the cellular metabolism and reduce microbial growth without affecting the organic matter removal is very promising for reducing the amount of sludge in wastewater treatment systems. In this study, two bioproducts were evaluated and compared with a well-known chemical (2,4-DiNitroPhenol – DNP in activated sludge treating petroleum refinery wastewater. In batch experiments, 10 mg/L of DNP, 0.8 mg/L of a bioproduct based on Folic Acid (FA and 10 mg/L of a bioproduct based on Stress Proteins (SP led to 30.6%, 43.2% and 29.8% lower disposal of total solids, respectively. Operating on a continuous regimen, the addition of 10 mg/L of the bioproduct based on SP led to 45.7% lower disposal for 50 days. In all cases, no loss of efficiency in the Chemical Oxygen Demand (COD removal was observed.

  17. Greenhouse gas emissions from the mineralisation process in a Sludge Treatment Reed Bed system: Seasonal variation and environmental impact

    DEFF Research Database (Denmark)

    Larsen, Julie Dam; Nielsen, Steen; Scheutz, Charlotte


    the annual greenhouse gas emission rate of the mineralisation process. The full-scale STRB at Helsinge wastewater treatment plant (WWTP) in Denmark was chosen as the study site. Gas emission rates were measured using static surface flux chambers. The measurements were carried out in October/November 2014...

  18. Microbial community analysis in sludge of anaerobic wastewater treatment systems : integrated culture-dependent and culture-independent approaches

    NARCIS (Netherlands)

    Roest, C.


    The need for clean water is increasing and anaerobic wastewater treatment can be used as a cost-effective solution for purification of organically polluted industrial waste streams. This thesis presents results from microbiological investigations of several full-scale and lab-scale anaerobic

  19. Characterization of the in situ ecophysiology of novel phylotypes in nutrient removal activated sludge treatment plants

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta


    with nutrient removal indicate the presence of a core set of bacterial genera. These organisms are likely responsible for the bulk of nutrient transformations underpinning the functions of these plants. While the basic activities of some of these genera in situ are known, there is little to no information......An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...

  20. Development of substance flow based Life Cycle Assessment tool for sewage sludge treatment and disposal

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Clavreul, Julie; Scheutz, Charlotte

    Life Cycle Assessment (LCA) is a method to quantify environmental impacts of products or systems. It is often done by correlating material and energy demands with certain input characteristics. An attempt was made to evaluate the robustness of the substance flow based LCA for wastewater and sludge...... treatment processes. Operational data of a conventional wastewater treatment plant over 12 years was collected. A cluster analysis was conducted to determine the relatedness of each input and output characteristic at the whole plant level. The results indicate that the output from the wastewater and sludge...


    Directory of Open Access Journals (Sweden)

    H. Alidadi, A. R. Parvaresh and M. R. Shamansouri


    Full Text Available 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 indicates 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.

  2. Effects of high salinity wastewater on methanogenic sludge bed systems

    NARCIS (Netherlands)

    Ismail, S.; Gonzalez-Contreras, P.A.; Jeison, D.A.; Lier, van J.B.


    The attainable loading potentials of anaerobic sludge bed systems are strongly dependent on the growth of granular biomass with a particular wastewater. Experiments were conducted to determine the effects of high salinity wastewater on the biological and physical properties of methanogenic sludge.


    Energy Technology Data Exchange (ETDEWEB)



    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.

  4. Gasification of yeast industry treatment plant sludge using downdraft Gasifier. (United States)

    Ayol, Azize; Tezer, Ozgun; Gurgen, Alim


    Sludges produced in biological wastewater treatment plants have rich organic materials in their characteristics. Recent research studies have focused on the energy recovery from sludge due to its high organic content. The gasification process is a thermal conversion technology transforming the chemical energy contained in a solid fuel into thermal energy and electricity. The produced syngas as a mixture of CO, CH 4 , H 2 and other gases can be used to generate electrical energy. The gasification of yeast industry sludge has been experimentally evaluated in a pilot scale downdraft-type gasifier as a route towards the energy recovery. The gasifier has 20 kg biomass/h fuel capacity. During gasification, the temperature achieved was more than 1,000°C in the gasifier, and then the syngas was transferred to the gas engine to yield the electricity. A load was connected to the grid box and approximately 1 kWh electrical power generation for 1 kg dry sludge was determined. The characteristics of residuals - ash, glassy material - were also analyzed. It was found that most of the heavy metals were fixed in the glassy material. Experimental results showed that the yeast industry sludge was an appropriate material for gasification studies and remarkable energy recovery was obtained in terms of power production by using syngas.

  5. The beneficial usage of water treatment sludge as pottery product ...

    African Journals Online (AJOL)

    Mineralogical compositions were determined using XRD, XRF for chemical composition and physical testing including Atterberg limit test and particles size distribution. Identification of beneficial usage is based on the characteristics of water treatment sludge. Keywords: chemical composition; mineral composition; physical ...

  6. Thermochemical treatment of sewage sludge ashes for phosphorus recovery. (United States)

    Adam, C; Peplinski, B; Michaelis, M; Kley, G; Simon, F-G


    Phosphorus (P) is an essential element for all living organisms and cannot be replaced. Municipal sewage sludge is a carrier of phosphorus, but also contains organic pollutants and heavy metals. A two-step thermal treatment is suggested, including mono-incineration of sewage sludge and subsequent thermochemical treatment of the ashes. Organic pollutants are completely destroyed by mono-incineration. The resulting sewage sludge ashes contain P, but also heavy metals. P in the ashes exhibits low bioavailability, a disadvantage in farming. Therefore, in a second thermochemical step, P is transferred into mineral phases available for plants, and heavy metals are removed as well. The thermochemical treatment was investigated in a laboratory-scale rotary furnace by treating seven different sewage sludge ashes under systematic variation of operational parameters. Heavy metal removal and the increase of the P-bioavailability were the focus of the investigation. The present experimental study shows that these objectives have been achieved with the proposed process. The P-bioavailability was significantly increased due to the formation of new mineral phases such as chlorapatite, farringtonite and stanfieldite during thermochemical treatment.

  7. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)

    Wastewater discharged from the edible oil industry contains a very concentrated amalgamation of organic and inorganic materials making it a problematic effluent to treat. The aim of this study was to evaluate the activated sludge treatment of edible oil effluent from a sunflower oil processing company in KwaZulu-Natal.

  8. Enzymatic Profiles of Activated Sludge from a Wastewater Treatment ...

    African Journals Online (AJOL)

    Activated sludge samples collected from a treatment plant, with foaming experience in the month of July, was characterized enzymatically. Hexokinase, Glyceraldehyde-3-phosphate dehydrogenase and Adenylate kinase activity assays were conducted before, during and after the foaming episode. The spectrum of enzyme ...

  9. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)



    Jul 3, 2003 ... Wastewater discharged from the edible oil industry contains a very concentrated amalgamation of organic and inorganic materials making it a problematic effluent to treat. The aim of this study was to evaluate the activated sludge treatment of edible oil effluent from a sunflower oil processing company in ...

  10. Effect of polyaluminium chloride water treatment sludge on effluent ...

    African Journals Online (AJOL)

    Water resources degeneration is accelerated by the discharge of untreated wastewater and its byproducts, hence, reuse of these wastes is a major contributor to sustaining fresh water for the coming decades. In this study, the reuse of polyaluminium water treatment sludge (PA-WTS) as a flocculant aid to improve the ...

  11. The degradation of antibiotic amoxicillin in the Fenton-activated sludge combined system. (United States)

    Guo, Ruixin; Xie, Xiaodan; Chen, Jianqiu


    The present study investigated the removal efficiency of amoxicillin by the Fenton process, individual activated sludge process and Fenton-activated sludge combined system. For the antibiotic at 1 g L(-1), the optimal conditions of the Fenton process included: 4 mL FeSO4·7H2O solution (20.43 g  L(-1)), 6 mL H2O2 solution (3%) and 40°C. Under the optimal conditions, the removal rate of amoxicillin achieved up to 80% in 70 min. In addition, the impact of amoxicillin on microorganism limited the removal capacity of the activated sludge process. When the concentration of amoxicillin was less than 350 mg L(-1), 69.04-88.79% of the antibiotic was removed. However, the antibiotic could not be treated by the activated sludge when the concentration increased up to 650 mg L(-1). On the other hand, ifamoxicillin was pretreated partly by the Fenton process it was then degraded completely by the same activated sludge. Thus, the combined system included two steps: 80% amoxicillin was degraded in step I and was removed completely in the cheaper biological treatment (step II). Our result showed that compared with the individual activated sludge process, the Fenton process improved the removal capacity of the subsequent activated sludge process in the combined system.

  12. A new oxic-settling-anaerobic (NOSA(®)) activated sludge process for minimizing excess sludge in secondary biological treatment plants: a pilot-scale evaluation of the absorption-biodegradation process. (United States)

    Wu, Ke; Li, Shi-Yu; Jiang, Feng; Wang, Jun; Liu, Guang-Li; Chen, Guang-Hao


    This study compared the sludge reduction performance of a new oxic-settling-anaerobic (NOSA) process with that of a conventional adsorption-biodegradation process. A 50 m(3)/d pilot trial system with two different process configurations was operated for 6 months. The NOSA process functioned effectively in removing both chemical oxygen demand and nitrogen with the efficiencies of 86 and 92.5%, respectively, which reduced approximately 40% of the excess sludge. In this research, 0.77 kg volatile suspended solids/d sludge vanished in the anaerobic tank, which accounted for 58.9% of the total sludge loss in the NOSA process. Economic calculation suggests that the new process can dramatically upgrade the sludge reduction in wastewater treatment plants without a digestion device, and the investment for fundamental upgrading can be recovered in 5-6 years by cutting the costs of excess sludge dewatering and disposal treatment.

  13. High Level Waste System Impacts from Acid Dissolution of Sludge

    Energy Technology Data Exchange (ETDEWEB)



    This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.

  14. Metaproteomics provides functional insight into activated sludge wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Paul Wilmes


    Full Text Available 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.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 alpha-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 beta oxidation, fatty acid synthesis and phosphate transport. Several proteins involved in cellular stress response were detected.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.

  15. Thermal power sludge – properties, treatment, utilization

    Directory of Open Access Journals (Sweden)

    Martin Sisol


    Full Text Available In this paper a knowledge about properties of thermal power sludge from coal combustion in smelting boilers is presented. The physical and technological properties of slag – granularity, density, specific, volume and pouring weight, hardness and decoupling – together with chemical properties influence its exploitation. The possibility of concentrating the Fe component by the mineral processing technologies (wet low-intenzity magnetic separation is verified. An industrial use of the slag in civil engineering, e.g. road construction, was realised. The slag-fly ashes are directly utilized in the cement production as a substitute of a part of natural raw materials. For the use of slag as the stoneware in the road construction, all the criteria are fulfilled.


    Directory of Open Access Journals (Sweden)

    Valerio Marroni


    Full Text Available An innovative bioremediation technology and strategy were applied to a former-quarry area in Imola (BO – Italy concerned by an incorrect environmental restoration of paper sludge, with subsequent uncontrolled biogas production and migration to the adjacent area. An Emergency Plan was implemented by the isolation of the buried sludge area and a characterization project was performed to define an appropriate permanently safe recovery. An innovative biological in situ treatment, avoiding paper sludge removal, was adopted; it was based on the use of tailored compost and enzymes to reduce methane production and concentration. This was integrated by specific monitoring piezometers for both biogas (CH4, CO2 and oxygen monthly measurements, and also the application of a respirometric technique application to buried sludge for assessing its stabilisation under aerobic and anaerobic conditions. This communication describes the strategy used, the treatment and monitoring system and the results of 3 years field pilot application. Monitoring work is still in progress.

  17. Treatment of 14 sludge types from wastewater treatment plants using bench and pilot thermal hydrolysis. (United States)

    Qiao, Wei; Sun, Yifei; Wang, Wei


    A total of 14 types of sludge from household sewage, mixture of domestic and industrial wastewater, and industrial and oil wastewater treatment plants were selected to evaluate the effectiveness and adaptability of thermal hydrolysis pre-treatment. Organic solubilization, dewatering improvement, volume reduction, high-strength filtrate biodegradation, and dewatered sludge incineration were investigated using bench and pilot thermal hydrolysis experiments (170 °C/60 min). Results showed that sludge types significantly affected the treatment effects. Organic content has a primary influence on thermal effects. The relationship between suspended solid (SS) solubilization and raw sludge organic content was linear with an R(2) of 0.73. The relationship between raw sludge organic content and treated sludge dewatering was linear with an R(2) of 0.86 and 0.65 for pilot and bench pre-treatments, respectively. Household and oil sludge possessed incineration possibilities with high heat value. Industrial and oil sludge filtrate was unsuitable for digestion to recover bioenergy.

  18. Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment. (United States)

    Remy, C; Lesjean, B; Waschnewski, J


    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.

  19. Treatment of municipal sewage sludge in supercritical water: A review. (United States)

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


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Energy recovery from thermal treatment of dewatered sludge in wastewater treatment plants. (United States)

    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.

  1. Fermentation and chemical treatment of pulp and paper mill sludge (United States)

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


    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. Geotechnical problems experienced during the construction of the sludge treatment unit of the main wastewater treatment plant in antalya

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Mustafa H. [Akdeniz University, Faculty of Engineering, Department of Civil Engineering, Antalya (Turkey)


    The treatment and disposal of wastewater still is a big problem of Antalya. The wastewater produced in the residential areas is biologically treated, the produced sludge, however, remains untreated. At the moment more than 60 t/day of dewatered sludge are buried at a landfill area located directly above the main groundwater resources of the city. As the area does not have any drainage and liner systems, it is believed that this kind of disposal constitutes a threat to the groundwater resources. Therefore, Antalya Metropolitan Municipality decided to add anaerobic sludge digestion units to the wastewater treatment plant. The sludge digestion tanks are considered to be built within the wastewater treatment plant area which is less than 1 km away from the beaches along the Mediterranean Sea. The purpose of this study is to examine the foundation soil in terms of its bearing capacity, consolidation settlement, and earthquake risks and to find out whether this construction site is suitable for building the sludge digestion tanks or not. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  3. Anaerobic stabilisation of sludge produced during municipal wastewater treatment by electrocoagulation. (United States)

    Hutnan, M; Drtil, M; Kalina, A


    Anaerobic digestion of sludge from small electrocoagulation wastewater treatment plant (SEWWTP) is described. The sludge for digestion (SEWWTP sludge) was taken from pilot-scale SEWWTP with the capacity of about 200-population equivalent (25 m3 of municipal wastewater per day). Due to the technology of wastewater treatment, the characteristics of SEWWTP sludge was different from sludge produced in conventional mechanical-biological wastewater treatment plant. Therefore, experiments were focused on possibilities of anaerobic sludge digestion and determination of conditions and parameters (amount and quality of the sludge, biogas production, etc.). Average COD removal efficiency in the pilot-scale SEWWTP exceeded 80%. Organic content of excess sludge (volatile suspended solids (VSS)) was in the range of 52.1-59.2% (these values are much lower compared to VSS content in raw sludge from conventional municipal wastewater treatment plant, where VSS is about 75%). Biogas production from anaerobic digestion of SEWWTP sludge was approximately three times lower compared to standard production in conventional municipal wastewater treatment plant. Low pH (6.5-6.7), high concentration of iron (up to 1400 mg/L) and aluminium (up to 1300 mg/L) and very low (almost zero) concentration of dissolved phosphorus in sludge water were the main factors limiting the rate of anaerobic processes. Based on these results, anaerobic digestion of SEWWTP sludge was not recommended as an appropriate stabilisation method.

  4. Treatment of oilfield wastewater containing polymer by the batch activated sludge reactor combined with a zerovalent iron/EDTA/air system. (United States)

    Lu, Mang; Wei, Xiaofang


    Laboratory-scale experiments were conducted in order to evaluate the performance of a novel treatment process for oilfield wastewater based on combining chemical oxidation, performed by a zerovalent iron (ZVI), ethylenediamine tetraacetic acid (EDTA) and air process, with biological degradation, carried out in a batch activated sludge reactor. The influence of some operating variables was studied. The results showed that the optimum pretreatment conditions were 150 mg/L EDTA, 20 g/L ZVI, and a 180-min reaction time, respectively. Under these conditions, removal efficiencies for hydrolyzed polyacrylamide (HPAM), total petroleum hydrocarbons (TPH), and chemical oxygen demand (COD) were 66%, 59%, and 45%, respectively. During the subsequent 40 h of bioremediation, the concentrations of HPAM, TPH, and COD were decreased to 10, 2 and 85 mg/L, respectively. At the end of experiments, the total removal efficiencies of HPAM, TPH, and COD were 96%, 97% and 92%, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Full Scale Sludge Treatment in Reed Beds in Moderate Climate—A Case Study

    Directory of Open Access Journals (Sweden)

    Artur Mennerich


    Full Text Available The wastewater treatment plant of Wathlingen, Germany, has a design capacity of 20,500 p.e. Since 2000, the sewage sludge has been treated in four reed beds with an area of 3000 m2 each. During this time, three of the four polders were emptied once and put into operation again, which has allowed for an evaluation of complete operation cycles from startup to sludge removal. This paper comprises data on polder construction and operating results as well as an economic evaluation of construction, operation, and sludge disposal costs. Results show that sludge DS mass may be reduced by at least 23% and at most 52%. Water content was reduced, but the DS concentration of the product excavated was not higher than around 20% DS. Operation experiences proved that the system is very user-friendly and requiring limited maintenance and control work. To make the best use of this technique, it is recommended a separate area for additional storage and dewatering is provided after the sludge from the polders is removed. This allows for the possibility for the operators to determine the appropriate time and conditions for final disposal.

  6. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    NARCIS (Netherlands)

    Tervahauta, T.H.; Bryant, I.M.; Hernandez Leal, L.; Buisman, C.J.N.; Zeeman, G.


    This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB) reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were

  7. Investigation of sewage sludge treatment using air plasma assisted gasification. (United States)

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


    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Multi-Criteria Sustainability Assessment of Urban Sludge Treatment Technologies

    DEFF Research Database (Denmark)

    An, Da; Xi, Beidou; Ren, Jingzheng


    This study aims at developing a sustainability assessment framework for assessing the technologies for the treatment of urban sewage sludge based on the logarithmic fuzzy preference programming based fuzzy analytic hierarchy process (LFPPFAHP) and extension theory. LFPPFAHP was employed...... to determine the weights of the criteria for sustainability assessment, and extension theory was used to prioritize the alternative technologies for the treatment of urban sewage sludge and grade their sustainability performances. An illustrative case including three technologies (compositing, incineration......, and resource utilization) was studied by the proposed method, and compositing, incineration, and resource utilization are recognized as "Moderately Sustainable", "Not Sustainable", and "Highly Sustainable", respectively. The sustainability sequence in the descending order is resource utilization, compositing...


    Directory of Open Access Journals (Sweden)

    Paula Piechna


    Full Text Available The aim of the presented study was: a assessment of activity of microorganisms developed in form of activated sludge and biofilm, b indirect assessment of the role of analyzed biocoenoses in removal of organic compounds in hybrid reactor with moving bed. Oxygen uptake rate tests (OUR have been used, and obtained results were presented as volumetric activity (expressed in mg O2/L · h and mass activity (expressed as mg O2/g VTS · h. Tests were conducted for three different variants, in which, as the biomass: 1 biofilm was used, 2 activated sludge was used, 3 biofilm and activated sludge were used. The biomass was collected from aerobic reactor from a wastewater treatment plant working in IFAS-MBBR system. The highest volumetric activity was observed for variant with biofilm and activated sludge, and the lowest for variant with biofilm only. Nonetheless, the highest value of oxygen uptake rate related to total volatile solids was observed for variant with biofilm and the lowest for activated sludge. Obtained results suggest, that during this research, at the wastewater treatment plant, the main role in removal of organic pollutants played the biomass developed in form of activated sludge.

  10. Influence of phosphorus elimination on sludge treatment and sludge usage at municipal wastewater treatment plants; Einfluss von P-Eliminierungsverfahren auf Schlammbehandlung und -verwertung bei der kommunalen Abwasserreinigung

    Energy Technology Data Exchange (ETDEWEB)

    Poepel, H.J.; Jardin, N.


    This report covers investigations with respect to the influence of the enhanced biological phosphorus removal process (EBPR) on sludge production, phosphate release during sludge treatment and the subsequent phosphorus feedback. Experiments in a semi-technical scale were performed using different sludge thickening (centrifuge, screening drum, gravity thickener) and stabilising (anaerobic-mesophilic and aerobic-thermophilic stabilisation) systems. Due the uptake of phosphorus as polyphosphate, the EBPR operation resulted in an additional sludge production of some 3 kg TS/kg P. Thickening of the excess sludge resulted only in a minor P-feedback. During sludge stabilisation a nearly complete hydrolysis of the polyphosphates was observed accompanied by a release of phosphate. A large part of the released phosphate was eliminated from the soluble phase by means of physico-chemical fixation which was identified to be mainly struvite precipitation and absorption. The resulting feedback was usually below 20% of the incoming P-load. Based on these findings a mathematical model to describe the P-release and the P-fixation was developed. The influence of physico-chemical phosphorus elimination on sludge production and the P-release during sludge treatment is described. Investigations were performed using a pilot plant equipped with and without phosphorus precipitation, followed by anaerobic-mesophilic stabilisation. The investigations focused on the influence of the relative amount of precipitant ({beta}=0,7 to 2), the P-concentration in the influent (15 to 20 mg/l P{sub tot}) and the sludge age (4 to 8 days) on the P-release and the P-feedback. Using AVR for phosphorus precipitation, an additional sludge production of 3,3 to 4 kg MLSS/kg Fe/Al was determined. No differences with respect to P-release and P-feedback were found between the plant with and the plant without phosphorus precipitation. The dewatering characteristics were usually improved by P-precipitation. (orig

  11. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor. (United States)

    Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y


    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.

  12. Microorganism communities and chemical characteristics in sludge-bamboo charcoal composting system. (United States)

    Hua, Li; Chen, Yingxu; Wu, Weixiang; Ma, Hongrui


    Microorganism communities and chemical characteristics in sludge-bamboo charcoal composting system were investigated to find the effect of bamboo charcoal on composting. According to a plate count test, abundances of bacteria, fungi and actinomycetes in the treatment with bamboo charcoal were several times higher than those in treatment without bamboo charcoal. In addition, terminal restriction fragment length polymorphism (TRFLP) analysis indicated that the bacterial community diversity in treatment with bamboo charcoal was greater than that of the control. Both results demonstrated that amendment with bamboo charcoal can increase microorganism population and microorganism community diversity in a sludge composting system. Moreover, the results of FTIR spectroscopy disclosed that aerobic composting can promote the formation of surface acid groups on bamboo charcoal. These surface acid groups may deprotonate and react with NH4+ to form stable complexes. Therefore, the increase of functional groups accompanied with greater assimilation of nitrogen by microorganisms could reduce nitrogen loss in sludge composting.

  13. Wastewater treatment sludge as a raw material for the production of Bacillus thuringiensis based biopesticides. (United States)

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


    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.

  14. Effects of Bio-sludge Concentration and Dilution Rate on the Efficiency of Sequencing Batch Reactor (SBR System for Textile Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Suntud Sirianuntapiboon


    Full Text Available The color removal efficiency of a sequencing batch reactor (SBR system with synthetic textile wastewater (STWW containing 80 mg/L disperse dye increased with the increase of mixed liquor suspended solids (MLSS or solids retention time (SRT. The color removal efficiency was over 98% at an MLSS of 4,000 mg/L and SRT of over 25 days. Also, the color removal efficiency decreased with the increase of dye concentration. Both disperse blue 60 and disperse red 60 repressed the growths and activities of both heterotrophic and denitrifying bacteria, but they did not show any effect on nitrifying bacteria. However, the SBR system did not show any change in color removal efficiency of both disperse red 60 and disperse blue 60. The SBR system showed quite low color, COD and BOD5 removal efficiencies with raw textile wastewater (TWW. But, the system removal efficiencies could be increased by dilution of the TWW and supplementation with glucose. The color removal efficiency of the system with four times diluted-TWW containing 1.875 g/L glucose was 69.6±4.0%. Moreover, contaminated-NaCl in STWW could depress color adsorption yields of living as well as dead bio-sludge.

  15. Modelling Cr(VI) removal by a combined carbon-activated sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Orozco, A. Micaela Ferro [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina); Contreras, Edgardo M. [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina)], E-mail:; Zaritzky, Noemi E. [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina); Fac. de Ingenieria, UNLP. 47 y 1 (B1900AJJ), La Plata (Argentina)


    The combined carbon-activated sludge process has been proposed as an alternative to protect the biomass against toxic substances in wastewaters; however, the information about the effect of powdered-activated carbon (PAC) addition in activated sludge reactors for the treatment of wastewaters containing Cr(VI) is limited. The objectives of the present study were: (a) to evaluate the removal of hexavalent chromium by (i) activated sludge microorganisms in aerobic batch reactors, (ii) powdered-activated carbon, and (iii) the combined action of powdered-activated carbon and biomass; (b) to propose mathematical models that interpret the experimental results. Different Cr(VI) removal systems were tested: (S1) biomass (activated sludge), (S2) PAC, and (S3) the combined activated carbon-biomass system. A Monod-based mathematical model was used to describe the kinetics of Cr(VI) removal in the system S1. A first-order kinetics with respect to Cr(VI) and PAC respectively, was proposed to model the removal of Cr(VI) in the system S2. Cr(VI) removal in the combined carbon-biomass system (S3) was faster than both Cr(VI) removal using PAC or activated sludge individually. Results showed that the removal of Cr(VI) using the activated carbon-biomass system (S3) was adequately described by combining the kinetic equations proposed for the systems S1 and S2.

  16. Communal sewage sludge treatement against the background of the new European Sewage Sludge Treatment Regulations; Kommunale Klaerschlammbehandlung vor dem Hintergrund der neuen Europaeischen Klaerschlammrichtlinien

    Energy Technology Data Exchange (ETDEWEB)



    The following issues were discussed at the Darmstadt conference: The European Sewage Sludge Treatment Regulation, hygienisation of sewage sludge, waste water purification without excess sludge production, stabilisation of sewage sludge, dewatering and disposal by combustion or utilisation as an agricultural fertilizer. [German] Themen des Darmstaedter Seminars Abwassertechnik waren: Europaeische Klaerschlammrichtlinie, Klaerschlammhygienisierung, Abwasserreinigung ohne Anfall von Ueberschussschlamm, Klaerschlammstabilisierung, Entwaesserung und Entsorgung durch Verbrennung oder in der Landwirtschaft. (UKE)

  17. Extracellular protein analysis of activated sludge and their functions in wastewater treatment plant by shotgun proteomics. (United States)

    Zhang, Peng; Shen, Yu; Guo, Jin-Song; Li, Chun; Wang, Han; Chen, You-Peng; Yan, Peng; Yang, Ji-Xiang; Fang, Fang


    In this work, proteins in extracellular polymeric substances extracted from anaerobic, anoxic and aerobic sludges of wastewater treatment plant (WWTP) were analyzed to probe their origins and functions. Extracellular proteins in WWTP sludges were identified using shotgun proteomics, and 130, 108 and 114 proteins in anaerobic, anoxic and aerobic samples were classified, respectively. Most proteins originated from cell and cell part, and their most major molecular functions were catalytic activity and binding activity. The results exhibited that the main roles of extracellular proteins in activated sludges were multivalence cations and organic molecules binding, as well as in catalysis and degradation. The catalytic activity proteins were more widespread in anaerobic sludge compared with those in anoxic and aerobic sludges. The structure difference between anaerobic and aerobic sludges could be associated with their catalytic activities proteins. The results also put forward a relation between the macro characteristics of activated sludges and micro functions of extracellular proteins in biological wastewater treatment process.

  18. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carlos J.; Reeve, Petra J.; Sawade, Emma [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Voldoire, Camille F. [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Newton, Kelly; Praptiwi, Radisti [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Collingnon, Lea [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Dreyfus, Jennifer [Allwater, Adelaide Services Alliance, Wakefield St, Adelaide, SA 5001 (Australia); Hobson, Peter [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Gaget, Virginie [University of Adelaide, Ecology and Environmental Sciences, School of Biological Sciences, Adelaide, SA 5005 (Australia); Newcombe, Gayle, E-mail: [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia)


    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10 days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. - Highlights: • Cyanobacteria in water treatment sludge significantly impact supernatant quality • Cyanobacteria can survive, and thrive, in sludge lagoon supernatant and in treatment sludge • Metabolite concentrations in cyanobacteria in sludge can increase up to 500% • The risk associated with supernatant recycling was assessed relative to available treatment barriers.

  19. Primary Treatment and Sludge Digestion Workshop. (United States)

    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;…

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

    NARCIS (Netherlands)

    Tawfik, A.; El-Gohary, F.; Temmink, B.G.


    The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 A degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times

  1. Determination and characterization of pharmaceuticals in sludge from municipal and livestock wastewater treatment plants. (United States)

    Ekpeghere, Kalu Ibe; Lee, Ji-Woo; Kim, Hee-Young; Shin, Sun-Kyoung; Oh, Jeong-Eun


    This study investigated 24 pharmaceuticals compounds belonging to the classes of analgesics, stimulants, anti-seizures, non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics in the sludge of 12 municipal sewage treatment plants (S-sludge) and 4 livestock wastewater treatment plants (L-sludge) located across Korea. Over 70% of the target compounds were detected in at least one sample of S-sludge and L-sludge. The total concentration of the target pharmaceutical compounds detected in S-sludge was 2.622-422.8 mg kg(-1)and the most dominant compound was acetylsalicylic acid (ASA: 0.374-367.0 mg kg(-1)) whereas in L-sludge, the total concentration was 43.87-156.8 mg kg(-1)and the most abundant compound was oxytetracycline (OTC: 34.54-86.39 mg kg(-1)). Cluster analysis revealed two distinct groups: group A, which were S-sludge samples including ASA, carbamazepine (CBM), and others, and group B were L-sludge samples, dominated by antibiotics (CTC, OTC, LIN). The total daily load amount of the target pharmaceuticals in S-sludge was 0.010-268.9 kg day(-1) while the L-sludge was 0.021-0.529 kg day(-1). The estimated amounts of the target pharmaceutical discharged from S-sludge and L-sludge into the Korean environment were 150.2 ± 47.94 ton yr(-1) and 15.05 ± 5.671 ton yr(-1) respectively, but the discharged amount of antibiotics from S-sludge (6.945 ton yr(-1)) was lower than that from L-sludge (9.234 ton yr(-1)). Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Atmospheric emission characterization of a novel sludge drying and co-combustion system. (United States)

    Lu, Shengyong; Yang, Liqin; Zhou, Fa; Wang, Fei; Yan, Jianhua; Li, Xiaodong; Chi, Yong; Cen, Kefa


    A novel system combining sludge drying and co-combustion with coal was applied in disposing sludge and its atmospheric emission characteristics were tested. The system was composed of a hollow blade paddle dryer, a thermal drying exhaust gas control system, a 75 tons/hr circulating fluidized bed and a flue gas cleaning system. The emissions of NH3, SO2, CH4 and some other pollutants released from thermal drying, and pollutants such as NOx, SO2 etc. discharged by the incinerator, were all tested. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in the flue gas from the incinerator were investigated as well. The results indicated that the concentrations of NOx and SO2 in the flue gas from the incinerator were 145 and 16 mg/m3, respectively. and the I-TEQ concentration of 2,3,7,8-substitued PCDD/Fs was 0.023 ng I-TEQ/Nm3. All these values were greatly lower than the emission standards of China. In addition, there was no obvious odor in the air around the sludge dryer. The results demonstrated that this drying and co-combustion system is efficient in controlling pollutants and is a feasible way for large-scale treatment of industrial sludge and sewage sludge.

  3. Flocculation and dewaterability of chemically enhanced primary treatment sludge by bioaugmentation with filamentous fungi. (United States)

    Murugesan, Kumarasamy; Selvam, Ammaiyappan; Wong, Jonathan W C


    In this study, filamentous fungal strains isolated from sewage sludge bioleached with iron-oxidizing bacteria were evaluated their effectiveness in improving the flocculation and dewaterability of chemically enhanced primary treatment (CEPT) sludge. Augmentation of the pre-grown mycelial biomass in the CEPT sludge had no significant changes in sludge pH but, improved sludge dewaterability, as evidenced from the decrease in capillary suction time. Improvement on sludge flocculation and dewaterability depended on the fungal strains, and a pellet forming Penicillium sp. was more effective than the fungal isolates producing filamentous form of mycelial biomass due to entrapment of sludge solids onto mycelial pellets. Fungal treatment also reduced the chemical oxygen demand of the CEPT sludge by 35-76%. Supplementation metal cations (Ca(2+), Mg(2+), and Fe(3+)) to fungal pre-augmented sludge rapidly improved the sludge dewaterability. This study indicates that augmentation of selective fungal biomass can be a potential method for CEPT sludge flocculation and dewaterability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Ecophysiology of novel core phylotypes in activated sludge wastewater treatment plants with nutrient removal

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta

    An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...... with nutrient removal in Denmark indicate a core set of bacterial genera. These core genera are suggested to be responsible for the bulk of nutrient transformations underpinning the functions of these plants. While we know the basic in situ activities of some of these genera, there is little to no information...... for the majority, and thus no indication as to their relevance to the ecology of these systems. The next logical step will therefore be to systematically characterize each of these organisms. To this end, this study applied in situ FISH based methods to characterize a selection of these phylotypes for which...

  5. [Effect of different sludge retention time (SRT) on municipal sewage sludge bioleaching continuous plug flow reaction system]. (United States)

    Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng; Wang, Dian-Zhan


    A plug-flow bio-reactor of 700 L working volume for sludge bioleaching was used in this study. The reactor was divided into six sections along the direction of the sludge movement. Fourteen days of continuous operation of sludge bioleaching with different sludge retention time (SRT) under the condition of 1.2 m3 x h(-1) aeration amount and 4 g x L(-1) of microbial nutritional substance was conducted. During sludge bioleaching, the dynamic changes of pH, DO, dewaterability (specific resistance to filtration, SRF) of sewage sludge in different sections were investigated in the present study. The results showed that sludge pH were maintained at 5.00, 3.00, 2.90, 2.70, 2.60 and 2.40 from section 1 to section 6 and the SRF of sludge was drastically decreased from initial 0.64 x 10(13) m x kg(-1) to the final 0.33 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 72 with SRT 2.5d. In addition, the sludge pH were maintained at 5.10, 4.10, 3.20, 2.90, 2.70 and 2.60, the DO value were 0.43, 1.47, 3.29, 4.76, 5.75 and 5.88 mg x L(-1) from section 1 to section 6, and the SRF of sludge was drastically decreased from initial 0.56 x 10(13) to the final 0.20 x 10(13) m x kg(-1) when bioleaching system reached stable at hour 120 with SRT 2 d. The pH value was increased to 3.00 at section 6 at hour 48 h with SRT 1.25 d. The bioleaching system imbalanced in this operation conditions because of the utilization efficiency of microbial nutritional substance by Acidibacillus spp. was decreased. The longer sludge retention time, the easier bioleaching system reached stable. 2 d could be used as the optimum sludge retention time in engineering application. The bioleached sludge was collected and dewatered by plate-and-frame filter press to the moisture content of dewatered sludge cake under 60%. This study would provide the necessary data to the engineering application on municipal sewage sludge bioleaching.

  6. Optimization of the do concentration in activated sludge systems treating petrochemical effluents

    Energy Technology Data Exchange (ETDEWEB)

    Van Haandel, A.; Cavalcanti, P. F.F.; Medeiros, U. T. P.


    Electric energy is normally one the important cost factors of activated sludge systems. If the aeration intensity is reduced, energy consumption will be lower, but the resulting reduction of the dissolved oxygen concentration in the mixed liquor may affect the treatment system in three ways: (1) reduction of the efficiency of organic material removal and nitrification, resulting in higher residual BOD, COD and NH{sub 3} concentrations in the effluent, (2) reduction of the metabolic activity of heterotrophic or auto trophic bacteria and (3) deterioration of the sludge settleability which may reduce the separation efficiency in the final settler. (Author)

  7. Occurrence and fate of acrylamide in water-recycling systems and sludge in aggregate industries. (United States)

    Junqua, Guillaume; Spinelli, Sylvie; Gonzalez, Catherine


    Acrylamide is a hazardous substance having irritant and toxic properties as well as carcinogen, mutagen, and impaired fertility possible effects. Acrylamide might be found in the environment as a consequence of the use of polyacrylamides (PAMs) widely added as a flocculant for water treatment. Acrylamide is a monomer used to produce polyacrylamide (PAM) polymers. This reaction of polymerization can be incomplete, and acrylamide molecules can be present as traces in the commercial polymer. Thus, the use of PAMs may generate a release of acrylamide in the environment. In aggregate industries, PAM is widely involved in recycling process and water reuse (aggregate washing). Indeed, these industries consume large quantities of water. Thus, European and French regulations have favored loops of recycling of water in order to reduce water withdrawals. The main goal of this article is to study the occurrence and fate of acrylamide in water-recycling process as well as in the sludge produced by the flocculation treatment process in aggregate production plants. Moreover, to strengthen the relevance of this article, the objective is also to demonstrate if the recycling system leads to an accumulation effect in waters and sludge and if free acrylamide could be released by sludge during their storage. To reach this objective, water sampled at different steps of recycling water process has been analyzed as well as different sludge corresponding to various storage times. The obtained results reveal no accumulation effect in the water of the water-recycling system nor in the sludge.

  8. Predicting the drying properties of sludge based on hydrothermal treatment under subcritical conditions. (United States)

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


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Bioaugmentation to improve nitrification in activated sludge treatment. (United States)

    Leu, Shao-Yuan; Stenstrom, Michael K


    Bioaugmentation is a proposed technique to improve nutrient removal in municipal wastewater treatment. Compared with commonly used nitrification/denitrification (NDN) processes, bioaugmentation may be able to reduce tankage or land requirements. Many approaches for bioaugmentation have been developed, but few studies have compared the benefits among different approaches. This paper quantifies the effectiveness of bioaugmentation processes and investigates three major "onsite" bioaugmentation alternatives: 1) the parallel-plants approach, which uses acclimated biomass grown in a nitrifying "long-SRT" (sludge retention time) plant to augment a low-SRT treatment plant; 2) the enricher-reactor approach, which uses an offline reactor to produce the augmentation cultures; and 3) the enricher-reactor/return activated sludge (ER-RAS) approach, which grows enrichment culture in a reaeration reactor that receives a portion of the recycle activated sludge. Kinetic models were developed to simulate each approach, and the benefits of various approaches are presented on the same basis with controllable parameters, such as bioaugmentation levels, aeration tank volume, and temperatures. Examples were given to illustrate the potential benefits of bioaugmentation by upgrading a "carbon-only" wastewater treatment plant to nitrification. Simulation results suggested that all bioaugmentation approaches can decrease the minimum SRT for nitrification. The parallel-plants approach creates the highest concentration of biomass but may fail at too low temperature. The ER-RAS approach likely would be more useful at lower temperature and required less reactor volume; enricher-reactor approach would likely be more advantageous in the presence of inhibitory compound(s).

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

    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…

  11. Enzyme treatment to decrease solids and improve digestion of primary sewage sludge

    CSIR Research Space (South Africa)

    Roman, HJ


    Full Text Available management, sewage sludge, sludge production, dewatering, disintegration. INTRODUCTION Wastewater treatment has developed slowly from the use of simple sewage farms to more sophisticated processes, such as activated sludge. However, this change has... wastewater treatment works (WWTW) effluents. For example, the European Union *Corresponding author. E-mail: (EU) currently operates over 40 300 WWTW, producing approx. 6.5 million tonnes of dry solids (DS) per annum...

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

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


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Mechanisms involved in Escherichia coli and Serratia marcescens removal during activated sludge wastewater treatment (United States)

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


    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

  14. System design description for the consolidated sludge sampling system for K Basins floor and fuel canisters

    Energy Technology Data Exchange (ETDEWEB)

    HECHT, S.L.


    This System Design Description describes the Consolidated Sludge Sampling System used in the gathering of sludge samples from K Basin floor and fuel canisters. This document provides additional information on the need for the system, the functions and requirements of the systems, the operations of the system, and the general work plan used in its' design and development.

  15. Fate of xenobiotic compounds and plants activity in reed bed sludge treatment

    DEFF Research Database (Denmark)

    Chen, Xijuan; Pauli, Udo; Rehfus, Stefan

    Sludge reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Europe since 1988. Although reed beds are considered as a low cost and low contamination method in reducing volume, breaking down organic matter and increasing the density of sludge......, however weather this enhanced biological treatment is suitable for degradation of xenobiotics, is not fully elucidated. This project has pointed out the benefits of using the biological sludge treatment plant to reduce xenobiotic compounds, and the capacity of plants to affect the treatment process. Three...... different plants: bulrush (Typha), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea) were planted into 12 containers with a size of 1m Х 1m X 1m which were builded with 20cm gravel and 50cm sludge to study the plants activity in sludge degradation process, 4 containers were left...

  16. Towards energy positive wastewater treatment by sludge treatment using free nitrous acid. (United States)

    Wang, Qilin; Hao, Xiaodi; Yuan, Zhiguo


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. 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. (United States)

    Ara, E; Sartaj, M; Kennedy, K


    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. © The Author(s) 2014.

  18. Barley Seed Germination/Root Elongation Toxicity Test For Evaluation Of Sludge Pre-Treatment

    DEFF Research Database (Denmark)

    Eriksson, Eva; Kusk, Kresten Ole; Barrett Sørensen, Mie

    Application of sludge from wastewater treatment plants (WWTPs) on agricultural land is an approach for nutrient recycling that rise challenges due to recalcitrant and harmful pollutants. In this study we assessed the feasibility of a seed germination test to evaluate sludge ecotoxicity and compared...... germination responses from two test parameters, root elongation and seed germination (sprouts elongation) of the barley (Hordeum vulgare). 2nd objective was to evaluate sewage sludge pre-treatments at batch-scale of sludge samples from two WWTPs using anaerobic digestion, and thermal and ozonation pre...

  19. Thermophilic slurry-phase treatment of petroleum hydrocarbon waste sludges

    Energy Technology Data Exchange (ETDEWEB)

    Castaldi, F.J.; Bombaugh, K.J. [Radian Corp., Austin, TX (United States); McFarland, B. [Chevron Research and Technology Co., Richmond, CA (United States)


    Chemoheterotrophic thermophilic bacteria were used to achieve enhanced hydrocarbon degradation during slurry-phase treatment of oily waste sludges from petroleum refinery operations. Aerobic and anaerobic bacterial cultures were examined under thermophilic conditions to assess the effects of mode of metabolism on the potential for petroleum hydrocarbon degradation. The study determined that both aerobic and anaerobic thermophilic bacteria are capable of growth on petroleum hydrocarbons. Thermophilic methanogenesis is feasible during the degradation of hydrocarbons when a strict anaerobic condition is achieved in a slurry bioreactor. Aerobic thermophilic bacteria achieved the largest apparent reduction in chemical oxygen demand, freon extractable oil, total and volatile solid,s and polycyclic aromatic hydrocarbons (PAHs) when treating oily waste sludges. The observed shift with time in the molecular weight distribution of hydrocarbon material was more pronounced under aerobic metabolic conditions than under strict anaerobic conditions. The changes in the hydrocarbon molecular weight distribution, infrared spectra, and PAH concentrations during slurry-phase treatment indicate that the aerobic thermophilic bioslurry achieved a higher degree of hydrocarbon degradation than the anaerobic thermophilic bioslurry during the same time period.

  20. Orthophosphate removal from aqueous solutions using drinking-water treatment sludge. (United States)

    Piaskowski, Krzysztof


    Drinking-water treatment sludge (DWTS) is a by-product generated during the production of drinking water where iron hydroxides are the main component of the sludge. The aim of the study presented here was to determine the effectiveness of using ferric sludge from two underground water treatment stations to remove orthophosphates from a model solution. The analyses were performed in static conditions. The sludge was dosed in a dry and suspended form. Using sludge dried at room temperature and preparing the suspension again proved to be much less effective in orthophosphate removal than using a suspension brought directly from the station. An increase in process effectiveness with a decreasing pH was observed for all the analysed sludge. Due to the low cost and high capability, DWTS has the potential to be utilised for cost-effective removal of phosphate from wastewater.

  1. Treatment of sewage sludges reduction of pollutants; Tratamiento de lodos residuales reduccion de contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Moreno A, J


    Considering the experiences of the Nuclear Research National Institute (ININ) in the treatment of sewage sludge, using gamma radiation it pretends to develop on a laboratory level and to propose the treatment: irradiation-composting of sewage sludge in order to degrade chemical toxic and destruction or inactivation of pathogenic organisms. (Author)

  2. Wastewater treatment in a hybrid activated sludge baffled reactor. (United States)

    Tizghadam, Mostafa; Dagot, Christophe; Baudu, Michel


    A novel hybrid activated sludge baffled reactor (HASBR), which contained both suspended and attached-growth biomass perfect mixing cells in series, was developed by installing standing and hanging baffles and introducing plastic brushes into a conventional activated sludge (CAS) reactor. It was used for the treatment of domestic wastewater. The effects on the operational performance of developing the suspended and attached-growth biomass and reactor configuration were investigated. The change of the flow regime from complete-mix to plug-flow, and the addition of plastic brushes as a support for biofilm, resulted in considerable improvements in the COD, nitrogen removal efficiency of domestic wastewater and sludge settling properties. In steady state, approximately 98+/-2% of the total COD and 98+/-2% of the ammonia of the influent were removed in the HASBR, when the influent wastewater concentration was 593+/-11 mg COD/L and 43+/-5 mg N/L, respectively, at a HRT of 10 h. These results were 93+/-3 and 6+/-3% for the CAS reactor, respectively. Approximately 90+/-7% of the total COD was removed in the HASBR, when the influent wastewater concentration was 654+/-16 mg COD/L at a 3h HRT, and in the organic loading rate (OLR) of 5.36kgCOD m(-3) day(-1). The result for the CAS reactor was 60+/-3%. Existing CAS plants can be upgraded by changing the reactor configuration and introducing biofilm support media into the aeration tank.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mawioo, Peter M., E-mail: [Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Rweyemamu, Audax; Garcia, Hector A.; Hooijmans, Christine M. [Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Brdjanovic, Damir [Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft (Netherlands)


    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. - Highlights: • There is lack of fast and efficient fecal sludge treatment options in emergencies. • Microwave treatment is rapid and efficient in sludge volume and pathogen reduction. • Power and contact time can be varied to reach diverse levels of sludge treatment.

  4. A strategy in wastewater treatment process for significant reduction of excess sludge production. (United States)

    Shiota, N; Akashi, A; Hasegawa, S


    A novel wastewater treatment process (S-TE PROCESS) with significantly reduced production of excess sludge has been developed. The process consists of two different stages, one for a biological wastewater treatment and the other for a thermophilic aerobic digestion of the resulting sludge. A portion of return sludge from the wastewater treatment step is injected into a thermophilic aerobic sludge digester (TASD), in which the injected sludge is solubilized by the action of thermophilic aerobic bacteria. The solubilized sludge is returned to the aeration tank in the wastewater treatment step for its further degradation. Pilot-scale facilities of the S-TE process and the conventional activated sludge process as a control, both treating the same industrial wastewater, were comparatively operated for totally 270 days. As a result, 93% reduction in overall excess sludge production was achieved in the S-TE operation. The SS solubilization rate in TASD was stable at around 30%. Only a slight increase in the effluent SS and TOC concentrations was observed compared with those of the control facility. Otherwise the removal efficiency of TOC was approximately 95% for both plants. A full-scale plant treating domestic sewage was operated for three years, showing 75% reduction of overall excess sludge production. It was concluded that the new process was feasible.

  5. Filterability and Sludge Concentration in Membrane Bioreactors


    Lousada-Ferreira, M.


    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of the sludge to be filtrated through a membrane, in a wastewater treatment system designated as Membrane Bioreactor (MBR). An MBR is a wastewater treatment system that combines an activated sludge proc...

  6. Effects of ferric hydroxid sludge dosage on sludge treatment/-disposal. Final report; Einfluesse einer Eisenschlammzugabe auf die Klaerschlammbehandlung/-entsorgung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, E.; Benzinger, S.


    A pilot plant consisting of two gravity thickeners, two sludge digesters and sludge dewatering by laboratory-frame filter press was operated on two different sewage water treatment plants. Ferric hydroxide sludge (FS) was treated together as with surplus sludge from enhanced biological removal of phosphorus (SS{sub EBPR}) as together with a mixture of primary and surplus sludge including precipitation sludge (PS+SS). One sludge treatment system was dosed with FS, the other serving as control unit operated without FS. In combined thickening in view of filterable solids, COD and P the quality of supernatant improved in most cases as well as the dried solid matter of the thickened sludge increased. In thickening of SS{sub EBPR} 45-70% P was refixed more than in the control system. Scum caused by hydrogen sulphide could be avoided in particular cases. There were no negative influences on the process of combined digestion with SS{sub EBPR} observed as well as with PS+SS. The degradation of organic solid matter was increased by FS-dosage>30 g Fe/kg TR{sub RS}. If present SS{sub EBPR}, hydrogen sulphide was reduced significantly; the content of methane in digester gas increased. Re-dissolved poly-P was refixed nearly completely. Sludge dewatering process was not influenced by FS, independent of the kind of post sludge conditioning. Nor was the sludge disposal restricted by FS. P-feedback from combined thickening, digestion and dewatering of SS{sub EBPR} decreased in comparison to the control unit with 16,8% (in relation to P{sub tot} influent) to 11,2 resp. 1,4% depending on the dosage of FS. (orig.) [Deutsch] Eine halbtechnische Versuchsanlage mit Schwerkrafteindickern, Faulbehaeltern und Entwaesserung mit einer Labor-Rahmenfilterpresse wurde auf zwei kommunalen Klaeranlagen betrieben. Eisenhydroxidschlamm (ES) wurde zum einen mit Ueberschussschlamm aus der erhoehten biologischen P-Elimination (UeSS{sub BIO-P}) und zum anderen mit einem Gemisch aus Primaer- und

  7. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas)

    DEFF Research Database (Denmark)

    Escola Casas, Monica; Chhetri, Ravi Kumar; Ooi, Gordon Tze Hoong


    amount, the last reactor (biofilm only) appeared to have the most effective biomass in respect of removing pharmaceuticals. In the batch experiment, out of 26 compounds, 16 were assessed to degrade more than 20% of the respective pharmaceutical within the Hybas train. In the continuous flow experiment......Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process, has been suggested as a possible solution for hospital wastewater treatment. Hybas......TM is a hybrid process, based on the integrated fixed-film activated sludge technology, where plastic carriers for biofilm growth are suspended within activated sludge. To investigate the potential of a hybrid system for the removal of pharmaceuticals in hospital wastewater a pilot plant consisting of a series...

  8. Using cement, lignite fly ash and baghouse filter waste for solidification of chromium electroplating treatment sludge

    Directory of Open Access Journals (Sweden)

    Wantawin, C.


    Full Text Available The objective of the study is to use baghouse filter waste as a binder mixed with cement and lignite fly ash to solidify sludge from chromium electroplating wastewater treatment. To save cost of solidification, reducing cement in binder and increasing sludge in the cube were focused on. Minimum percent cement in binder of 20 for solidification of chromium sludge was found when controlling lignite fly ash to baghouse filter waste at the ratio of 30:70, sludge to binder ratio of 0.5, water to mixer ratio of 0.3 and curing time of 7 days. Increase of sludge to binder ratio from 0.5 to 0.75 and 1 resulted in increase in the minimum percent cement in binder up to 30 percent in both ratios. With the minimum percent cement in binder, the calculated cement to sludge ratios for samples with sludge to binder ratios of 0.5, 0.75 and 1 were 0.4, 0.4 and 0.3 respectively. Leaching chromium and compressive strength of the samples with these ratios could achieve the solidified waste standard by the Ministry of Industry. For solidification of chromium sludge at sludge to binder ratio of 1, the lowest cost binder ratio of cement to lignite fly ash and baghouse filter waste in this study was 30:21:49. The cost of binder in this ratio was 718 baht per ton dry sludge.

  9. Cosmetic wastewater treatment by upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

    Puyol, D.; Monsalvo, V.M.; Mohedano, A.F. [Seccion de Ingenieria Quimica, Facultad de Ciencias, Universidad Autonoma de Madrid, C/ Francisco Tomas y Valiente 7, 28049, Madrid (Spain); Sanz, J.L. [Departamento de Biologia Molecular, Facultad de Ciencias, Universidad Autonoma de Madrid, C/ Francisco Tomas y Valiente 7, 28049, Madrid (Spain); Rodriguez, J.J., E-mail: [Seccion de Ingenieria Quimica, Facultad de Ciencias, Universidad Autonoma de Madrid, C/ Francisco Tomas y Valiente 7, 28049, Madrid (Spain)


    Anaerobic treatment of pre-settled cosmetic wastewater in batch and continuous experiments has been investigated. Biodegradability tests showed high COD and solid removal efficiencies (about 70%), being the hydrolysis of solids the limiting step of the process. Continuous treatment was carried out in an upflow anaerobic sludge blanket reactor. High COD and TSS removal efficiencies (up to 95% and 85%, respectively) were achieved over a wide range of organic load rate (from 1.8 to 9.2 g TCOD L{sup -1} day{sup -1}). Methanogenesis inhibition was observed in batch assays, which can be predicted by means of a Haldane-based inhibition model. Both COD and solid removal were modelled by Monod and pseudo-first order models, respectively.

  10. Thermal treatment of sewage sludge from waste water. Tratamiento termico de lodos procedentes de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Andreottola, G. (Universidad de Trento (Italy)); Canziani, R.; Ragazzi, M. (Politicnico de Milan (Italy))


    Thermal Treatment of sewage sludge can be beneficial as a pre-treatment step of many treatment/disposal options, but above all, it allows the recovery of the energetic content sludge. Energy recovery from sewage sludge can be performed in many ways; direct incineration thermal drying followed by incineration and co-combustion with municipal solid wastes or other non conventional fuels. Another option is the recovery of waste energy (e.g. from an endo thermal engine using biogas as fuel) to dry sludge wich, in turn can be used as a fuel. The paper will evaluate several options of thermal treatment of sewage sludge, with particular emphasis on the energetic yield from different processes. (Author)

  11. Innovative wastewater treatment as a prerequisite for the use of sludge in agriculture

    Directory of Open Access Journals (Sweden)

    Piuković-Babičković Blaženka


    Full Text Available This paper is based on the research done in water supply companies on the territory of Vojvodina in the Republic of Serbia. The paper presents an innovative model for wastewater treatment, because wastewater treatment and the disposal of sludge, produced during such treatment, are issues to be tackled not only by the Republic of Serbia, but also other countries in the region and elsewhere. The aim of the paper is to point out, how correct wastewater and sludge treatment can produce sludge, which has valuable agronomic properties. The paper seeks to encourage the correct use of sludge in agriculture in line with Directive 86/278/EEC, adopted by the Council of the European Economic Community to promote the use of sludge in agriculture on reasonable grounds, by ensuring its proper use.

  12. Selective hydrolysis of wastewater sludge. Part 1. Model calculations and cost benefit analysis for Esbjerg West waste water treatment plant, Denmark

    Energy Technology Data Exchange (ETDEWEB)

    OEstergaard, N. (Eurotec West A/S (DK)); Thomsen, Anne Belinda; Thygesen, Anders; Bangsoe Nielsen, H. (Risoe National Laboratory, DTU (DK)); Rasmussen, Soeren (SamRas (DK))


    The project 'Selective hydrolysis of wastewater sludge' investigates the possibilities of utilizing selective hydrolysis of sludge at waste water treatment plants to increase the production of biogas based power and heat, and at the same time reduce power consumption for handling and treatment of nitrogen and sludge as well as for disposal of the sludge. The selective hydrolysis system is based on the fact that an anaerobic digestion before a hydrolysis treatment increases the hydrolysis efficiency, as the production of volatile organic components, which might inhibit the hydrolysis efficiency, are not produced to the same extent as may be the case for a hydrolysis made on un-digested material. Furthermore it is possible to separate ammonia from the sludge without using chemicals; it has, however, proven difficult to treat wastewater sludge, as the sludge seems to be difficult to treat in the laboratory using simple equipment. Esbjerg Wastewater Treatment Plant West, Denmark, is used as model plant for the calculations of the benefits using selective hydrolysis of sludge as if established at the existing sludge digester system. The plant is a traditional build plant based on the activated sludge concept in addition to traditional digester technology. The plant treats combined household and factory wastewater with a considerable amount of the wastewater received from the industries. During the project period Esbjerg Treatment Plant West went through considerable process changes, thus the results presented in this report are based on historical plant characteristics and may be viewed as conservative relative to what actually may be obtainable. (BA)

  13. Using cement, lignite fly ash and baghouse filter waste for solidification of chromium electroplating treatment sludge


    Wantawin, C.; Chobthiangtham, P.


    The objective of the study is to use baghouse filter waste as a binder mixed with cement and lignite fly ash to solidify sludge from chromium electroplating wastewater treatment. To save cost of solidification, reducing cement in binder and increasing sludge in the cube were focused on. Minimum percent cement in binder of 20 for solidification of chromium sludge was found when controlling lignite fly ash to baghouse filter waste at the ratio of 30:70, sludge to binder ratio of 0.5, water to m...

  14. Gas composition of sludge residue profiles in a sludge treatment reed bed between loadings

    DEFF Research Database (Denmark)

    Larsen, Julie Dam; Nielsen, Steen M; Scheutz, Charlotte


    space, the concentration of CH4 often exceeded the concentration of carbon dioxide (CO2). However, the total emission of CO2 from the surface of the sludge residue exceeded the total emission of CH4, suggesting that CO2 was mainly produced in the layer of newly applied sludge and/or that CO2 was emitted...... the resting period. As the resting period proceeded, atmospheric air re-entered the pore space at all depth levels. The methane (CH4) concentration was at its highest during the first part of the resting period, and then declined as the sludge residue became more dewatered and thereby aerated. In the pore...... from the sludge residue more readily compared to CH4....

  15. Feasibility analysis of a sewage sludge treatment by an irradiation plant in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, J.; Balcazar, M. [Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, C.P. 52045 Estado de Mexico (Mexico); Colin, A. [Universidad Autonoma del Estado de Mexico, Toluca (Mexico); Tavera, L. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico D.F. (Mexico)


    Technical and economic analyses of an irradiation plant for sewage sludge treatment determined that an appropriate place for the first sludge electron irradiator in Mexico would be the sewage water treatment plant located north of Toluca in the State of Mexico. This treatment plant is mainly used for domestic wastewater and produces an approximate volume of 70 ton d-] liquid sewage sludge. Considering a 50 k W power of a 10 MeV electron linear accelerator, an irradiation dose of S KGy and a treatment capacity of 346 tons per day, it is estimated that the treatment cost would be of $9.00 US dollars per ton. (Author)

  16. Feasibility analysis of a sewage sludge treatment by an irradiation plant in Mexico

    CERN Document Server

    Moreno, J; Colin, A; Tavera, L


    Technical and economic analyses of an irradiation plant for sewage sludge treatment determined that an appropriate place for the first sludge electron irradiator in Mexico would be the sewage water treatment plant located north of Toluca in the State of Mexico. This treatment plant is mainly used for domestic wastewater and produces an approximate volume of 70 ton d-] liquid sewage sludge. Considering a 50 k W power of a 10 MeV electron linear accelerator, an irradiation dose of S KGy and a treatment capacity of 346 tons per day, it is estimated that the treatment cost would be of $9.00 US dollars per ton. (Author)

  17. Biological anoxic phosphorus removal in a continuous-flow external nitrification activated sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Kapagiannidis, A. G.; Aivasidis, A.


    Application of Biological Nutrient Removal (BNR) process in wastewater treatment is necessitated for the protection of water bodies from eutrophication. an alternative BNR method is tested for simultaneous Carbon (C), Nitrogen (N) and Phosphorus (P) removal in a continuous-flow bench scale plant for municipal wastewater treatment. The plant operation is based on the activity of two microbial populations which grow under different operational conditions (two sludge system). (Author)

  18. Evaluation of the functional activity of activated sludge from local waste water treatment plant in the Arctic region

    Directory of Open Access Journals (Sweden)

    Il'inskiy V. V.


    Full Text Available The paper considers characteristics of the activated sludge in the local wastewater treatment plant (LWTP and its ability to purify fully domestic sewage water in the Far North. Biochemical process of destruction of organic pollutants is influenced by a microbial complex functioning in aeration tanks. Taking into account climatic conditions of the region where the organic matter degradation processes are slowed, and lack of control over the operation, efficiency and occupational safety of LWTPs, it seems to be important to study the physiological characteristics of the bacteria used in bioremediation, and their ability to maximize the purifying domestic sewage in the Arctic region. Undue intervention in the biosphere systems leads to disruption of the balance of internal and external ecosystems communications. The goal of research is studying structural determination and functioning of activated sludge bacteriocenosis of LWTP TOPAS-5 (GK "Topol-ECO" in certain physical and chemical conditions of the habitat, and establishing completeness of cleaning process in this treatment plant. The paper considers the structure (quantitative and qualitative composition and function of LWTP activated sludge bacteriocenosis functioning in the Arctic region. The estimation of the activated sludge of full waste water treatment process of the LWTP has been given. The research's results have allowed to identify and determine the bacterial count of physiological groups of microorganisms purified domestic sewage; to isolate from activated sludge the bioflocculant-producing microorganisms' on the experimental medium; to evaluate efficiency of LWTP work in the Arctic region

  19. Carbon Footprint Analyses of Mainstream Wastewater Treatment Technologies under Different Sludge Treatment Scenarios in China

    Directory of Open Access Journals (Sweden)

    Chunyan Chai


    Full Text Available With rapid urbanization and infrastructure investment, wastewater treatment plants (WWTPs in Chinese cities are putting increased pressure on energy consumption and exacerbating greenhouse gas (GHG emissions. A carbon footprint is provided as a tool to quantify the life cycle GHG emissions and identify opportunities to reduce climate change impacts. This study examined three mainstream wastewater treatment technologies: Anaerobic–Anoxic–Oxic (A–A–O, Sequencing Batch Reactor (SBR and Oxygen Ditch, considering four different sludge treatment alternatives for small-to-medium-sized WWTPs. Following the life cycle approach, process design data and emission factors were used by the model to calculate the carbon footprint. Results found that direct emissions of CO2 and N2O, and indirect emissions of electricity use, are significant contributors to the carbon footprint. Although sludge anaerobic digestion and biogas recovery could significantly contribute to emission reduction, it was less beneficial for Oxygen Ditch than the other two treatment technologies due to its low sludge production. The influence of choosing “high risk” or “low risk” N2O emission factors on the carbon footprint was also investigated in this study. Oxygen Ditch was assessed as “low risk” of N2O emissions while SBR was “high risk”. The carbon footprint of A–A–O with sludge anaerobic digestion and energy recovery was more resilient to changes of N2O emission factors and control of N2O emissions, though process design parameters (i.e., effluent total nitrogen (TN concentration, mixed-liquor recycle (MLR rates and solids retention time (SRT and operation conditions (i.e., nitrite concentration are critical for reducing carbon footprint of SBR. Analyses of carbon footprints suggested that aerobic treatment of sludge not only favors the generation of large amounts of CO2, but also the emissions of N2O, so the rationale of reducing aerobic treatment and

  20. Treatment of real wastewater using co-culture of immobilized Chlorella vulgaris and suspended activated sludge. (United States)

    Mujtaba, Ghulam; Lee, Kisay


    The use of algal-bacterial symbiotic association establishes a sustainable and cost-effective strategy in wastewater treatment. Using municipal wastewater, the removal performances of inorganic nutrients (nitrogen and phosphorus) and organic pollutants were investigated by the co-culture system having different inoculum ratios (R) of suspended activated sludge to alginate-immobilized microalgae Chlorella vulgaris. The co-culture reactors with lower R ratios obtained more removal of nitrogen than in pure culture of C. vulgaris. The reactor with R = 0.5 (sludge/microalgae) showed the highest performance representing 66% removal after 24 h and 95% removal after 84 h. Phosphorus was completely eliminated (100%) in the co-culture system with inoculum ratios of 0.5 and 1.0 after 24 h and in the pure C. vulgaris culture after 36 h. The COD level was greatly reduced in the activated sludge reactor, while, it was increasing in pure C. vulgaris culture after 24 h of incubation. However, COD was almost stabilized after 24 h in the reactors with high R ratios such as 2.0, 5.0, and 10 due to the higher concentration of activated sludge. The growth of C. vulgaris was promoted from 0.03 g/L/d to 0.05 g/L/d in the co-culture of low inoculum ratios such as R = 0.5, implying that there exist an optimum inoculum ratio in the co-culture system in order to achieve efficient removal of nutrients. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    NARCIS (Netherlands)

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


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

  2. Innovative energy concept for sludge treatment using renewable resources[Held jointly with the 4. Canadian organic residuals and biosolids managment conference

    Energy Technology Data Exchange (ETDEWEB)

    Muller, J.A. [PFI Consulting Engineers, Hannover (Germany); Stuben, M. [Abwasserverband Wolfsburg, Wolfsburg (Germany)


    Agricultural sludge utilization is increasingly restricted by legal limits, leading to a growing demand for alternative sludge disposal solutions. One of the key alternatives to land application of sludge are thermal processes. Dried sludge can be used in many incineration processes, however sludge drying can increase disposal costs. The use of waste heat for drying is an economically and ecologically favorable option. Cogeneration plants operated with biogas from renewable resources are a source for excess heat and play an important role in producing energy from field crops, and yet no useful utilization for the excess heat of biogas plants can be found. Sewage sludge drying proves to be the ideal process for re-utilizing excess heat from biogas plants. Due to the low temperature level of the cooling water only a few drying technologies can be used, such as solar drying in combination with floor heating, low temperature belt drying systems and others. This paper discussed dimensioning for 2 applications of this innovative combination of biogas plants and sewage sludge drying. A flow chart of a combined sludge treatment and biogas plant was provided. The paper discussed heat production and drying capacity as well as the choice of drying process. The paper also discussed economic conditions for sludge drying. Two case studies were presented to explain the process. It was concluded that the utilization of excess heat from biogas plants for sludge drying is an ecologically and economically sensible combination that enables the wastewater treatment plant operator to abandon agricultural reuse and to concentrate on the longer-term safe thermal disposal option, without increasing costs for sludge disposal. 1 tab., 6 figs.

  3. Leito de drenagem: sistema natural para redução de volume de lodo de estação de tratamento de água Draining beds: natural system for sludge volume reduction in the water treatment plant

    Directory of Open Access Journals (Sweden)

    Cali Laguna Achon


    Full Text Available As Estações de Tratamento de Água (ETAs tem funcionamento semelhante a uma indústria e podem em diversas etapas gerar resíduos que, na maioria das ETAs, são lançados nos corpos d’água sem tratamento. Neste trabalho avaliou-se o desempenho de Leitos de Drenagem, para o desaguamento de lodo, provenientes de ETAs de ciclo completo que empregam sulfato de alumínio e cloreto de polialumínio (PACl, como coagulantes. Analisou-se as características, a drenagem e secagem dos amostras de lodo e característica do drenado. Os Leitos de Drenagem mostraram-se eficientes para desaguamento e redução de volume de lodo de ETA, de forma natural, sem consumo de energia ou adição de produtos químicos. Obteve-se, aos sete dias, reduções da ordem de 87 % em volume para os lodos de PACl e 83 % para o lodo de Sulfato de Alumínio e teor de sólidos totais 28% e 31% respectivamente.In this work the performance of Draining Beds for sludge dewatering was assessed. The sludge was provided from full cycle Water Treatment Plants (WTPs that employ aluminum sulfate and polyaluminium chloride (PACl as coagulants. The characteristics, drainage and drying of samples of sludge and characteristic of drained were analysed. The Draining Beds were shown to be efficient for dewatering and sludge volume reduction in the WTP, in a natural way, without energy consumption or adding of chemical products. On the seventh day, it was possible to obtain reduction around 87% in volume for PACl sludge and 83% for the aluminum sulfate sludge and total solids content of 28 and 31% respectively.

  4. Ultrasound technology effect on wastewater sludge treatment; Efecto de los ultrasonidos en el tratamiento de lodos de depuradora de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Mesas Diaz, J. A.


    The ultrasound technology has been used since long time ago in the medicine, food industry, cosmetics and cleaning systems; but during the last few years is when this technology has stated to be used in the wastewater and sludge treatment industry. The application of low frequency and high intensity ultrasound in the wastewater and sludge treatment has numerous benefits. The ultrasound technology improves the aerobic and anaerobic digestion process, increases the biogas production, improves the sludge dewatering, reduces the polymer consumption, reduces the final biosolids production, reduces or removes the bulking and foaming problems,and enhances nutrient removal (N, P). (Author) 7 refs.

  5. Electrodialytic treatment for metal removal from sewage sludge ash from fluidized bed combustion

    DEFF Research Database (Denmark)

    Pazos, Marta; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.


    to treat sewage sludge. By its use, the high amount of sludge is reduced to a small quantity of ash and thermal destruction of toxic organic constituents is obtained. Conversely, heavy metals are retained in the ash. In this work the possibility for electrodialytic metal removal for sewage sludge ash from...... FBSC was studied. A detailed characterization of the sewage sludge ash was done initially, determining that, with the exception of Cd, the other heavy metals (Cr, Cu, Pb, Ni and Zn) were under the limiting levels of Danish legislation for the use of sewage sludge as fertilizer. After 14 days...... of electrodialytic treatment, the Cd concentration was reduced to values below the limiting concentration. In all experiments the concentrations of other metals were under limiting values of the Danish legislation. It can be concluded that the electrodialytic treatment is an adequate alternative to reduce the Cd...

  6. Sludge treatment wetlands: a review on the state of the art. (United States)

    Uggetti, Enrica; Ferrer, Ivet; Llorens, Esther; García, Joan


    Sludge management has become a key issue in wastewater treatment, representing some 20-60% of the operational costs of conventional wastewater treatment plants. The high water content of the sludge results in large daily flow rates to be handled and treated. Thus, the search for methods to improve sludge volume reduction continues to be of major interest. The technology known as sludge treatment wetlands has been used for sludge dewatering since the late 1980s. Major advantages include its low energy requirements, reduced operating and maintenance costs, and a reasonable integration in the environment. However, the number of plants in operation is still low in comparison with conventional technologies. This study represents a review of the state of the art of sludge treatment wetlands. The main characteristics and operational aspects of the technology are described, including a summary of the main results reported in the literature. Finally, the efficiency of sludge treatment wetlands versus conventional treatments is compared. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Evaluation of physical stability and leachability of Portland Pozzolona Cement (PPC) solidified chemical sludge generated from textile wastewater treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Hema, E-mail: [TERI University, Plot No. 10, Institutional Area, Vasant Kunj, New Delhi (India); Pandey, Suneel [Centre for Regulatory and Policy Research, The Energy and Resources Institute (TERI), India Habitat Centre, New Delhi (India)


    Highlights: Black-Right-Pointing-Pointer Stabilization/solidification of chemical sludge from textile wastewater treatment plants using Portland Pozzolona Cement (PPC) containing fly ash. Black-Right-Pointing-Pointer Physical engineering (compressive strength and block density) indicates that sludge has potential to be reused for construction purpose after stabilization/solidification. Black-Right-Pointing-Pointer Leaching of heavy metals from stabilized/solidified materials were within stipulated limits. Black-Right-Pointing-Pointer There is a modification of microstructural properties of PPC with sludge addition as indicated by XRD and SEM patterns. - Abstract: The chemical sludge generated from the treatment of textile dyeing wastewater is a hazardous waste as per Indian Hazardous Waste Management rules. In this paper, stabilization/solidification of chemical sludge was carried out to explore its reuse potential in the construction materials. Portland Pozzolona Cement (PPC) was selected as the binder system which is commercially available cement with 10-25% fly ash interground in it. The stabilized/solidified blocks were evaluated in terms of unconfined compressive strength, block density and leaching of heavy metals. The compressive strength (3.62-33.62 MPa) and block density (1222.17-1688.72 kg/m{sup 3}) values as well as the negligible leaching of heavy metals from the stabilized/solidified blocks indicate that there is a potential of its use for structural and non-structural applications.

  8. Soil and pasture P concentration in a Fraxinus excelsior L. silvopastoral system fertilised with different types of sewage sludge (United States)

    Ferreiro-Domínguez, Nuria; Nair, Vimala; Rigueiro-Rodríguez, Antonio; Rosa Mosquera-Losada, María


    In Europe, sewage sludge should be stabilised before using as fertiliser in agriculture. Depending on the stabilisation process that is used, sewage sludge has different characteristics, nutrient contents and soil nutrient incorporation rates. Sewage sludge is usually applied on a plant-available N or total metal concentration basic, and therefore, P concentrations can be well above crop needs. Leaching of excess P can threaten surface and ground waters with eutrophication. In this context, recent studies have demonstrated that the implementation of agroforestry systems could reduce the P leaching risk compared with conventional agricultural systems due to the different localisation of tree and crop roots which enhance nutrient uptake. The aim of this study was to evaluate during three consecutive years the effect of municipal sewage sludge stabilised by anaerobic digestion, composting, and pelletisation on concentration of P in soil and pasture compared to control treatments (mineral and no fertilisation) in a silvopastoral system established under Fraxinus excelsior L. in Galicia (Spain). The results showed that at the beginning of the study, the fertilisation with mineral increased more the total and available P in soil than the fertilisation with sewage sludge probably because the sludge nutrient release rate is slower than those from mineral fertilisers. The increment of soil available P caused by the mineral fertiliser implied an improvement of the P concentration in the pasture. However, in the last year of the experiment it was observed a positive effect of the fertilisation with pelletised sludge on the concentration of P in pasture compared with the composted sludge and the mineral fertiliser probably due to the annual application of this type of sludge. Therefore, the establishment of silvopastoral systems and their fertilisation with pelletized sludge should be recommended because the pelletized sludge increases the concentration of P in the pasture and

  9. Performance of a pilot-scale sewage treatment: an up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactors combined system by sulfur-redox reaction process under low-temperature conditions. (United States)

    Takahashi, Masanobu; Yamaguchi, Takashi; Kuramoto, Yoshiharu; Nagano, Akihiro; Shimozaki, Satoshi; Sumino, Haruhiko; Araki, Nobuo; Yamazaki, Shinichi; Kawakami, Shuji; Harada, Hideki


    Performance of a wastewater treatment system utilizing a sulfur-redox reaction of microbes was investigated using a pilot-scale reactor that was fed with actual sewage. The system consisted of an up-flow anaerobic sludge blanket (UASB) reactor and a down-flow hanging sponge (DHS) reactor with a recirculation line. Consequently, the total CODCr (465±147 mg L(-1); total BOD of 207±68 mg L(-1)) at the influent was reduced (70±14 mg L(-1); total BOD of 9±2 mg L(-1)) at the DHS effluent under the conditions of an overall hydraulic retention time of 12 h, a recirculation ratio of 2, and a low-sewage temperature of 7.0±2.8 °C. A microbial analysis revealed that sulfate-reducing bacteria contributed to the degradation of organic matter in the UASB reactor even in low temperatures. The utilized sulfur-redox reaction is applicable for low-strength wastewater treatment under low-temperature conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Recent development in the treatment of oily sludge from petroleum industry: a review. (United States)

    Hu, Guangji; Li, Jianbing; Zeng, Guangming


    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. Copyright © 2013 Elsevier B.V. All rights reserved.


    Directory of Open Access Journals (Sweden)

    Makisha Nikolay Alekseevich


    ments held. A combination of aerobic and anaerobic processes helps provide the proper quality of integrated biological treatment. Chambers of the aeration reactor are also equipped with the polymer feed of various compositions. Sludge treatment that is also strongly needed was performed by means of aerobic stabilization accompanied by ejecting aeration. The experiment findings demonstrate its substantial effect in terms of both components, including sewage and sludge treatment.

  12. Nutrient release, recovery and removal from waste sludge of a biological nutrient removal system. (United States)

    Wang, Yi; Zheng, Shu-Jian; Pei, Li-Ying; Ke, Li; Peng, Dang-Cong; Xia, Si-Qing


    The uncontrolled release of nutrients from waste sludge results in nitrogen and phosphorus overloading in wastewater treatment plants when supernatant is returned to the inlet. A controlled release, recovery and removal of nutrient from the waste sludge of a Biological Nutrient Removal system (BNR) are investigated. Results showed that the supernatant was of high mineral salt, high electrical conductivity and poor biodegradability, in addition to high nitrogen and phosphorus concentrations after the waste sludge was hydrolysed through sodium dodecyl sulphate addition. Subsequently, over 91.8% of phosphorus and 10.5% of nitrogen in the supernatants were extracted by the crystallization method under the conditions of 9.5 pH and 400 rpm. The precipitate was mainly struvite according to X-ray diffraction and morphological examination. A multistage anoxic-oxic Moving Bed Biofilm Reactor (MBBR) was then adopted to remove the residual carbon, nitrogen and phosphorus in the supernatant. The MBBR exhibited good performance in simultaneously removing carbon, nitrogen and phosphorus under a short aeration time, which accounted for 31.25% of a cycle. Fluorescence in situ hybridization analysis demonstrated that nitrifiers presented mainly in floc, although higher extracellular polymeric substance content, especially DNA, appeared in the biofilm. Thus, a combination of hydrolysis and precipitation, followed by the MBBR, can complete the nutrient release from the waste sludge of a BNR system, recovers nutrients from the hydrolysed liquor and removes nutrients from leftovers effectively.

  13. Environmental comparison of alternative treatments for sewage sludge: An Italian case study. (United States)

    Lombardi, Lidia; Nocita, Cristina; Bettazzi, Elena; Fibbi, Donatella; Carnevale, Ennio


    A Life Cycle Assessment (LCA) was applied to compare different alternatives for sewage sludge treatment: such as land spreading, composting, incineration, landfill and wet oxidation. The LCA system boundaries include mechanical dewatering, the alternative treatment, transport, and final disposal/recovery of residues. Cases of recovered materials produced as outputs from the systems, were resolved by expanding the system boundaries to include avoided primary productions. The impact assessment was calculated using the CML-IA baseline method. Results showed that the incineration of sewage sludge with electricity production and solid residues recovery collects the lowest impact indicator values in the categories human toxicity, fresh water aquatic ecotoxicity, acidification and eutrophication, while it has the highest values for the categories global warming and ozone layer depletion. Land spreading has the lowest values for the categories abiotic depletion, fossil fuel depletion, global warming, ozone layer depletion and photochemical oxidation, while it collects the highest values for terrestrial ecotoxicity and eutrophication. Wet oxidation has just one of the best indicators (terrestrial ecotoxicity) and three of the worst ones (abiotic depletion, human toxicity and fresh water aquatic ecotoxicity). Composting process shows intermediate results. Landfill has the worst performances in global warming, photochemical oxidation and acidification. Results indicate that if the aim is to reduce the effect of the common practice of sludge land spreading on human and ecosystem toxicity, on acidification and on eutrophication, incineration with energy recovery would clearly improve the environmental performance of those indicators, but an increase in resource depletion and global warming is unavoidable. However, these conclusions are strictly linked to the effective recovery of solid residues from incineration, as the results are shown to be very sensitive with respect to

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

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


    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. Study on anaerobic digestion treatment of hazardous colistin sulphate contained pharmaceutical sludge. (United States)

    Yin, Fubin; Wang, Dongling; Li, Zifu; Ohlsen, Thomas; Hartwig, Peter; Czekalla, Sven


    Pharmaceutical sludge is considered as a hazardous substance with high treatment and disposal fees. Anaerobic digestion could not only transform the hazardous substance into activated sludge, but also generate valuable biogas. This research had two objectives. First: studying the feasibility of anaerobic digestion and determining the biochemical methane potential (BMP) of pharmaceutical sludge under different Inoculum to substrate TS ratios (ISRs) of 0, 0.65, 2.58 and 10.32 in mesophilic condition of 37±1°C. Secondly, investigating the removal efficiency of colistin sulphate during anaerobic digestion. The results showed that the use of anaerobic digestion to treat the pharmaceutical sludge is feasible and that it can completely eliminate the colistin sulphate. The highest biogas production from pharmaceutical sludge is 499.46 mL/g TS at an ISR of 10.32. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Sludge treatment by integrated ultrasound-Fenton process: Characterization of sludge organic matter and its impact on PAHs removal. (United States)

    Ke, Yaowei; Ning, Xun-An; Liang, Jieying; Zou, Haiyuan; Sun, Jian; Cai, Hualing; Lin, Meiqing; Li, Ruijing; Zhang, Yaping


    In this work, the impact of organic matter on the degradation of polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge by ultrasound-Fenton process has been studied. Sludge organic matter (SOM) was characterized and the degradation efficiencies of PAHs at various oxidation intensities (Fenton's reagent of 20, 70, and 140mmol/L, ultrasonic densities of 0.36, 0.90, and 1.80W/cm(3), and reaction time of 15, 25, and 40min) were determined. The results showed that 75.52-84.40% of PAHs and 16.32-31.13% of SOM had degraded after ultrasound-Fenton treatment, confirming the competitive relation between both of them for degradation. The aliphatic SOM fractions were preferentially oxidized owing to their easily degradable properties, while equimolar amounts of the aromatic moieties would require more oxidant compared to the aliphatic fractions. Correlation analysis demonstrated that SOM with its lower content, stronger polarity, and a higher proportion of labile organic fraction was more favourable for PAHs degradation. In addition, the SOM fractions were decomposed to biodegradable matter after treatment, which further enhance the biodegradability of sludge. This study provides insights into the role of SOM in PAHs removal by AOPs, and confirms that the ultrasound-Fenton treatment could not only effectively degrade PAHs, but also modify SOM. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Utilization of Paper Sludge Wastes for Treatment of Wastewater from Food Processing Industries

    Directory of Open Access Journals (Sweden)

    Tohru Suzuki


    Full Text Available The food processing industries usually produced large amount of wastewater containing fine and small particles. It takes long time for complete settlement of the fine and small particles in the wastewater. The coagulation method appears to become one of the useful treatments. New inorganic coagulant named “Agoclean‒P” has been developed from paper sludge ash. The treatment by coagulation and flocculation were carried out for the wastewater from three different food processing industries namely soup, tofu, and natto. “Hi‒Biah‒System”, which is an in‒situ solidification system, was used for the continuous treatment of wastewater. The parameters for the water quality were pH, five‒day biochemical oxygen demand (BOD5, chemical oxygen demand (COD, total suspended solids (TSS, total nitrogen (TN and total phosphorus (TP. These parameters after the treatment became much lower values relative to those obtained before the treatment.

  18. Microbial activities in a vertical-flow wetland system treating sewage sludge with high organic loads

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R. Y.; Perissol, C.; Baldy, V.; Bonin, G.; Korboulewsky, N.


    The rhizosphere is the most active zone in treatment wetlands where take place physicochemical and biological processes between the substrate, plants, microorganisms, and contaminants. Microorganisms play the key role in the mineralisation of organic matter. substrate respiration and phosphatase activities (acid and alkaline) were chosen as indicators of microbial activities, and studied in a vertical-flow wetland system receiving sewage sludge with high organic loads under the Mediterranean climate. (Author)

  19. Use of alum water treatment sludge to stabilize C and immobilize P and metals in composts. (United States)

    Haynes, R J; Zhou, Y-F


    Alum water treatment sludge is composed of amorphous hydroxyl-Al, which has variable charge surfaces with a large Brunauer-Emmett-Teller (BET) surface area (103 m(-2) g(-1)) capable of specific adsorption of organic matter molecules, phosphate, and heavy metals. The effects of adding dried, ground, alum water treatment sludge (10% w/w) to the feedstock for composting municipal green waste alone, green waste plus poultry manure, or green waste plus biosolids were determined. Addition of water treatment sludge reduced water soluble C, microbial biomass C, CO2 evolution, extractable P, and extractable heavy metals during composting. The decrease in CO2 evolution (i.e., C sequestration) was greatest for poultry manure and least for biosolid composts. The effects of addition of water treatment sludge to mature green waste-based poultry manure and biosolid composts were also determined in a 24-week incubation experiment. The composts were either incubated alone or after addition to a soil. Extractable P and heavy metal concentrations were decreased by additions of water treatment sludge in all treatments, and CO2 evolution was also reduced from the poultry manure compost over the first 16-18 weeks. However, for biosolid compost, addition of water treatment sludge increased microbial biomass C and CO2 evolution rate over the entire 24-week incubation period. This was attributed to the greatly reduced extractable heavy metal concentrations (As, Cr, Cu, Pb, and Zn) present following addition of water treatment sludge, and thus increased microbial activity. It was concluded that addition of water treatment sludge reduces concentrations of extractable P and heavy metals in composts and that its effect on organic matter stabilization is much greater during the composting process than for mature compost because levels of easily decomposable organic matter are initially much higher in the feedstock than those in matured composts.

  20. Water Treatment Plant Sludges--An Update of the State of the Art: Part 2. (United States)

    American Water Works Association Journal, 1978


    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)

  1. Sludge reduction by aquatic worms in wastewater treatment : with emphasis on the potential application of Lumbriculus variegatus

    NARCIS (Netherlands)

    Elissen, H.J.H.


    In wastewater treatment plants (WWTPs), large amounts of biological waste sludge are produced. In the Netherlands, the application of this sludge in agriculture or disposal in landfills is no longer allowed, mainly because of its high heavy metal content. The sludge therefore generally is

  2. Potential investigation of Reusing Ardabil Municipal Wastewater Treatment Plant Sludge Based on AHP and TOPSIS Models

    Directory of Open Access Journals (Sweden)

    Bizhan Maghsoudlou Kamali


    Full Text Available Introduction :By ever-increasing of population, shortage of water resources and the necessity of wastewater treatment, huge volumes of sludge that is a byproduct of wastewater treatment, requires to be disposed in environmentally secure ways. The target of specifying strategic preferences of reuse of sludge has been to find the correct way of disposal or beneficial use of sludge. Material and methods: In this study, to select the best alternative for reuse of wastewater sludge two systematic methods are introduced, which four alternatives for reuse of sludge (use in agriculture, use in green space, biogas, desert combat are introduced and they are compared by four main parameters including: 1- physicochemical 2-biological 3 - economic, social and cultural, and 4 - environmental pollution situation, that each contains some criteria. In this study, first each of the related parameters and criteria are compared by the expert groups of and through questionnaire. Then these weights are entered into Expert Choice software for the analyze of AHP model and paired comparisons and weightings have been done on the related parameters and criteria. Ultimately, the output of the software is entered into TOPSIS software for the analyze of TOPSIS model until the best alternative is selected. Results: sludge of Ardabil municipal wastewater treatment plant, according to standards and EPA regulations is eligible to class B, and due to the chemical in terms of heavy metals have special (excellent quality and contains considerable quantities of organic substance, nutrients and micronutrients which indicates the fertilizer value of the sludge. Conclusion: The result of this comparison has shown that the application of sludge in green spaces is the most appropriate alternative and then use in agriculture, biogas alternative, and desert combat alternative are, respectively, placed in the second to fourth preference for the reuse of sludge derived from municipal


    Energy Technology Data Exchange (ETDEWEB)



    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.

  4. The use of mathematical models for diagnosis of activated sludge systems in WWTP (United States)

    Drewnowski, Jakub; Zmarzły, Marcin


    In this study diagnosis of activated sludge systems in wastewater treatment plant (WWTP) was investigated. Diagnosis of technical objects can be realized in many ways. One of the divisions of the diagnostic methods include modelling with or without a model of the object. The first of these is the analysis of the symptoms for which, based on the parameter values, the abnormality in the diagnosed objects are sought. Another way is to use models of objects undergoing diagnosis. In this case, the diagnosis comes down to a comparison of information from the response object model or the estimated parameters of the model with data from the real object. The aim of this study was to evaluate an innovative concept of the possible use the mathematical model and computer simulation in the diagnosis and control of activated sludge systems in WWTP.

  5. A comparative study of wastewater treatment, from a fish canning factory, in a granular and a flocculent sludge SBR

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Sanchez, A.; Garrido, J. M.; Mendez, R.


    Sequencing Batch Reactors (SBR) process utilizes a fill and draw reactor with complete mixing during the reaction stage and where subsequent stages of aeration and clarification occur in the same tank. These systems often operates with flocculent sludge with a relatively low sludge volume index, around 100 ml/g-TSS, and sludge settling rate of around 1 m/h. (Author)

  6. Effect of microalgae/activated sludge ratio on cooperative treatment of anaerobic effluent of municipal wastewater. (United States)

    Roudsari, Fatemeh Pourasgharian; Mehrnia, Mohammad Reza; Asadi, Akram; Moayedi, Zohreh; Ranjbar, Reza


    In this work, capability of the green microalga (MA), Chlorella vulgaris, in treating synthetic anaerobic effluent of municipal wastewater was investigated. While pure C. vulgaris (100 % MA) provided maximum soluble chemical oxygen demand (sCOD) and N-NH4(+) removal efficiencies of 27 and 72 % respectively, addition of activated sludge (AS) to MA in different mass ratios (91, 80, 66.7, 9 % MA) improved wastewater treatment efficiency. Thus giving maximum sCOD and N-NH4(+) removal efficiencies 85 and 86.3 % (for MA/AS = 10/1), respectively. Utilizing AS without C. vulgaris, for treating the synthetic wastewater resulted in 87 % maximum sCOD and 42 % maximum N-NH4(+) removal efficiencies. Furthermore, algal growth and specific growth rates were measured in the systems with microalga as the dominant cellular population. As a result, faster algal growth was observed in mixed systems. Specific growth rate of C. vulgaris was 0.14 (day(-1)) in 100 % MA and 0.39 (day(-1)) in 80 % MA. Finally, data gathered by online measurement of dissolved oxygen indicate that algae-activated sludge mixture improves photosynthetic activity of examined microalga strain during anaerobic effluent treatment.

  7. Energy generation in a Microbial Fuel Cell using anaerobic sludge from a wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Vinicius Fabiano Passos

    Full Text Available ABSTRACT In microbial fuel cells (MFCs, the oxidation of organic compounds catalyzed by microorganisms (anode generates electricity via electron transfer to an external circuit that acts as an electron acceptor (cathode. Microbial fuel cells differ in terms of the microorganisms employed and the nature of the oxidized organic compound. In this study, a consortium of anaerobic microorganisms helped to treat the secondary sludge obtained from a sewage treatment plant. The microorganisms were grown in a 250 mL bioreactor containing a carbon cloth. The reactor was fed with media containing acetate (as the carbon source for 48 days. Concomitantly, the electrochemical data were measured with the aid of a digital multimeter and data acquisition system. At the beginning of the MFC operation, power density was low, probably due to slow microorganism growth and adhesion. The power density increased from the 15th day of operation, reaching a value of 13.5 μW cm–2 after ca. 24 days of operation, and remained stable until the end of the process. Compared with data in the literature, this power density value is promising; improvements in the MFC design and operation could increase this value even further. The system investigated herein employed excess sludge as a biocatalyst in an MFC. This opens up the possibility of using organic acids and/or carbohydrate-rich effluents to feed MFCs, and thereby provide simultaneous effluent treatment and energy generation.

  8. Reduction of Fecal Streptococcus and Salmonella by selected treatment methods for sludge and organic waste

    DEFF Research Database (Denmark)

    Jepsen, Svend Erik; Krause, Michael; Grüttner, Henrik


    The increasing utilization of waste water sludge and source-separated organic household waste in agriculture has brought the quality aspects into focus, among others the hygienic aspects. In this study, the reducting effect on Fecal Streptococcus (FS) and Salmonella of different methods...... for stabilization and methods for further treatment of sludge and organic waste has been investigated. The most common methods for stabilization, i.e. aerobic and anaerobic stabilization, only reduce the indicator organisms by approximately 1 logarithmic decade. Methods for further treatment of sludge and organic...... waste have shown reductions of microorganisms allowing for unrestricted utilization in agriculture, meeting the product control:FS below 100/g and no Salmonella detected. The effect of storage of sludge at summer and winter temperatures respectively has been investigated. At temperatures (around 20°C...

  9. Greywater treatment in an aerobic SBR: sludge structure and kinetics. (United States)

    Rojas-Z, U; Fajardo-O, C; Moreno-Andrade, I; Monroy, O


    In order to have an efficient operation, sequencing batch reactors (SBR) must support granular biomass with high conversion rates, settling properties, and be able to deal with the inherent variability of the composition of real wastewaters. In this study, the effect of the influent composition and the specific organic loading rate (Bx) on the granulation process was evaluated in two SBRs, fed with greywater (GW) and a synthetic medium (SM). The feeding with SM led to the formation of compact granular biomass, with a sludge volume index (SVI) of 22.4 mL g-1, and a zone settling velocity (ZSV) of 13.1 m h-1. In contrast, feeding with GW induced the formation of filamentous granules, with lower settling properties (SVI = 165 mL g-1 and ZSV = 10 m h-1), when the system was operated at high Bx (4.4 kg COD kg VSS-1 d-1). However, the reduction of the average Bx to 2 kg COD kg VSS-1 d-1 induced an improvement in the morphology and properties of the granules (SVI = 98 mL g-1 and ZSV = 13 m h-1). Furthermore, the kinetic analysis indicated that granules cultivated with SM were formed by fast growing microorganisms with a high cell yield, whereas those cultivated in GW presented a much lower cell yield.


    Directory of Open Access Journals (Sweden)

    Olena Semenova


    Full Text Available Purpose: Biochemical purification of wastewater containing refined petroleum products takes place due to the oxidation of pollutants by active sludge organisms. As a result of this process the intense consumption of pollutants by active sludge and its growth occurs. Therefore, the possibility to use active sludge containing refined petroleum products after wastewater treatment requires its stabilization. Methods: In this work the oxidation by a 30% hydrogen peroxide solution was studied for its use as a stabilizer. Chemical oxidizers, including hydrogen peroxide destroy organic polymers retaining free water thus promoting water release from the structure of sludge particles. On the other hand remains of fine structured oxidized biopolymers can lead to filter clogging, that is, reduce moisture exchange of sludge. Results: The experiment was carried out to find out the correlation between the doses of hydrogen peroxide and the resistivity value of sludge filtration. Discussion: Stabilized active sludge can be used as a fuel for boiler rooms, which in its turn will reduce natural gas consumption for the enterprise needs.

  11. Biological phosphorus and nitrogen removal in a single sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Hans


    The primary aim of this thesis was to investigate the process stability of a single sludge activated system designed for the combined operation of enhanced biological phosphorus removal (EBPR) and nitrogen removal. A pilot plant at the Sjoelunda wastewater treatment plant in Malmoe, Sweden, has formed the basis for the investigation. The pilot plant study showed that the concentration of total phosphorus on average was low in the effluent, below 0.5 mg P/l. Simultaneously with the highest concentrations of phosphorus in the effluent, the lowest COD/P ratios in the effluent were recorded. A recurrent pattern of high concentrations of phosphorus was observed every year in July, which is the industrial holiday month in Sweden. Other instances of increased phosphorus concentrations in the secondary effluent illustrate the effect of prolonged periods of rain. Increasing flow rates due to rain lead to a dilution and a change in the composition of the COD in the influent wastewater. The COD/P and VFA/P ratios decrease with decreasing concentrations of COD. It was also shown that high removal ratios of both nitrogen and phosphorus during long periods are possible. The nitrogen removal was stable during the whole investigated period, whereas the phosphorus removal was unstable during prolonged periods with low concentrations of COD in the influent water. The combined biological phosphorus and nitrogen removal process implies that during these periods the risk of recirculating nitrate to the anaerobic reactor increases. Such a recirculation both stabilizes the nitrogen removal and withdraws some of the readily degradable organic material from the bio-P bacteria. The main conclusion of this study is that a phosphorus limited EBPR process can cope with the day to day variations, but occasionally, measures have to be taken if the demands for phosphorus removal are stringent. 49 refs, 8 figs, 1 tab

  12. Characterization, Modeling and Application of Aerobic Granular Sludge for Wastewater Treatment (United States)

    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.

  13. Separation, Characterization and Fouling Potential of Sludge Waters from Different Biological Wastewater Treatment Processes

    KAUST Repository

    Xue, Jinkai


    The major limitation, which hinders the wider application of membrane technology and increases the operating costs of membranes involved in wastewater treatment plants, is membrane fouling induced by organic matter. Extracellular polymeric products (EPS) and soluble microbial products (SMP) are the two most mentioned major foulants in publications, for which the debate on precise definitions seems to be endless. Therefore, a concept of sludge water, which conceptually covers both EPS and SMP, has been developed in this research. A standard procedure of sludge water separation, which is centrifugation at 4000g for 15 min followed by 1.2μm glass fiber filter filtration, was established based on separation experiments with membrane tank sludge from the KAUST MBR wastewater treatment plant. Afterwards, sludge waters from the KAUST MBR WWTP anoxic tank, aerobic tank and membrane tank as well as sludge waters from the Jeddah WWTP anoxic tank, aerobic tank and secondary effluent were produced through the previously developed standard procedure. The obtained sludge water samples were thereafter characterized with TOC/COD, LC-­‐OCD and F-­‐EEM, which showed that KAUST anoxic/ aerobic /membrane tank sludge waters had similar characteristics for all investigated parameters, yet the influent naturally had a higher DOC and biopolymer concentration. Moreover, lower TOC/COD, negligible biopolymers and low levels of humics were found in KAUST effluent. Compared with the KAUST MBR WWTP, the Jeddah WWTP’s sludge waters generally had higher DOC and biopolymer concentrations. To investigate sludge water fouling potential, the KAUST membrane tank sludge water as well as the Jeddah secondary effluent were filtrated through a membrane array consisting of an ultrafiltration (UF) Millipore RC10kDa at the first step followed by a nanofiltration (NF) KOCH Acid/Base stable NF200 at the second step. It was found that cake layer and standard blocking occurred simultaneously during both

  14. Anaerobic treatment of sludge: focusing on reduction of LAS concentration in sludge

    DEFF Research Database (Denmark)

    Haagensen, Frank; Mogensen, Anders Skibsted; Angelidaki, Irini


    between transformed and bioavailable LAS12 was found, indicating that it is merely the bioavailable fraction of LAS12 that is transformed by anaerobic digestion. The results from the present study are promising and indicate that a great potential for biological degradation of LAS is possible even......Anaerobic degradation of linear alkylbenzene sulfonates (LAS) was tested in continuous stirred tank reactors (CSTR). LAS12 was used as a model compound and was spiked on sewage sludge. The experiments clearly showed that transformation of LAS12 occurred under anaerobic conditions. The degree...... at anaerobic conditions....

  15. Microwave and thermal pretreatment as methods for increasing the biogas potential of secondary sludge from municipal wastewater treatment plants

    DEFF Research Database (Denmark)

    Kuglarz, Mariusz; Karakashev, Dimitar Borisov; Angelidaki, Irini


    In the present study, the sludge was pretreated with microwave irradiation and low-temperature thermal method, both conducted under the same temperature range (30–100°C). Microwave pretreatment was found to be superior over the thermal treatment with respect to sludge solubilization and biogas...... experiments indicated that pre-treated sludge (microwave irradiation: 900W, temperature: 60–70°C) gave 35% more methane, compared to untreated sludge. Moreover, the results of this study clearly demonstrated that microwave pretreated sludge showed better degree of sanitation....

  16. Modelling inorganic material in activated sludge systems

    African Journals Online (AJOL)



    Apr 2, 2004 ... Water Research Group, Department of Civil Engineering, University of Cape Town, Rondebosch, Cape 7707, South Africa. Abstract ..... Calculation method. In more detail, for each SB or SSP of a system in an investigation, the OHO and/or PAO active fractions (favOHO , favPAO) for FA, ND or. NDBEPR ...

  17. Coagulant recovery from water treatment plant sludge and reuse in post-treatment of UASB reactor effluent treating municipal wastewater. (United States)

    Nair, Abhilash T; Ahammed, M Mansoor


    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.

  18. Characterization of the In Situ Ecophysiology of Novel Phylotypes in Nutrient Removal Activated Sludge Treatment Plants.

    Directory of Open Access Journals (Sweden)

    Simon Jon McIlroy

    Full Text Available An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants with nutrient removal indicate the presence of a core set of bacterial genera. These organisms are likely responsible for the bulk of nutrient transformations underpinning the functions of these plants. While the basic activities of some of these genera in situ are known, there is little to no information for the majority. This study applied microautoradiography coupled with fluorescence in situ hybridization (MAR-FISH for the in situ characterization of selected genus-level-phylotypes for which limited physiological information is available. These included Sulfuritalea and A21b, both within the class Betaproteobacteria, as well as Kaga01, within sub-group 10 of the phylum Acidobacteria. While the Sulfuritalea spp. were observed to be metabolically versatile, the A21b and Kaga01 phylotypes appeared to be highly specialized.

  19. System for the Reduction of Substances in Reject Water from Reed-Bed Sludge Mineralization Plants

    DEFF Research Database (Denmark)


    The invention is a system for the reduction of substances in reject water from reed-bed sludge mineralization plants (also referred to as sludge dewatering reed-beds). The systems utilizes the composition of substances in reject water from reed-beds and that of sludge to reduce substance mass from...... the reject water via recirculation into a mixed reactor and back onto the reed-beds. The mixed rector consists of a container in which sludge (that is typically loaded directly on to reed-beds) is mixed with recirculated reject water from reed-beds. The sludge mixture has a definable hydraulic retention time...... within the container. The solution is then applied to the reed-beds, which dewaters, converts, and partially mineralize the sludge mixture. The reject water from the reed-beds is split where up to100% of the reject water is recirculated back to the mixed reactor and the remaining usually disposed...

  20. Characterization and evaluation of potential reuse options for wastewater sludge and combined sewer system sediments in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, B.; Mendez, J.M.; Barrios, J.A.; Salgado, G.; Sheinbaum, C.


    Combined sewer systems generate sediments that have characteristics similar to those of primary sludge. Mexico City has such a system composed of a network of pipes, regulation structures (dams, basins) and open channels. The annual generation of sediments is estimated in 2.8 Mm{sup 3}, which includes 0.41 Mm{sup 3} of sludge. As a result, the total capacity for transporting water is reduced considerably, making necessary to extract yearly an approximate 0.85 Mm{sup 3} of those materials and to send them to a final disposal site with a capacity that is being exhausted. As part of the local Governmental effort, this project evaluates the quality of sediments from 6 dams, 4 regulation basins, 2 open channels, and 3 transfer stations. Also, sludge from 20 wastewater treatment plants was sampled. The results showed an important presence of lead and hydrocarbons in some sediments, and some sludge samples contained arsenic and nickel above the limits. Moreover, microbial levels exceeded the limits in all the sediments and sludge samples. Erosion was linked to the generation of an important amount of sediments based on lead concentration. A classification was established to determine the degree of contamination of the sediments as well as the required treatment to allow their potential reuse. (author)

  1. Improvement of anaerobic digestion of sewage sludge through microwave pre-treatment. (United States)

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


    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Sludge hydrothermal treatments. Oxidising atmosphere effects on biopolymers and physical properties. (United States)

    Urrea, José L; García, Manuel; Collado, Sergio; Oulego, Paula; Díaz, Mario


    In this work, the role of an oxidising atmosphere during the hydrothermal treatment of an activated sludge at 160 °C and 40 bar, was determined. The composition and molecular weight sizes of the soluble biopolymers generated during the sludge treatment in presence (wet oxidation "WO") or absence (thermal hydrolysis "TH") of oxygen were compared. Likewise, the characteristics of organic material, settleability, colour and pH of the treated sludge during both treatments were analysed. The thermal treatment in presence of oxygen provided better results in terms of solubilisation, settleability and mineralisation. WO initially favoured a more intense cellular lysis, causing a higher degree of solubilisation than that achieved by TH. Either in presence or absence of oxygen, thermal treatments caused a marked worsening of the settleability of the sludge. However, the degradation of biopolymers during WO led subsequently to an improvement of the settleability properties for longer reaction times. Both treatments caused a fast solubilisation of biopolymers at the beginning by effect of the release of extracellular and intracellular material from sludge. Subsequently, the presence of oxygen produced a significant decrease in the concentration of those biopolymers. In contrast, the proteins were the only one biopolymer that was degraded during TH. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Reliability of a commercial photometric system for analysis of heavy metals in sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Schwedt, G.; Hoeckendorf, A.


    Comparisons of methods for the analysis of lead, cadmium, chromium, copper, nickel, and zinc in sewage sludges are presented. The results of photometric determinations by means of a complete commercial system are compared to those of instrumental analysis by AAS and OES-ICP. In three sewage sludge samples and one sludge sample certificated by EG, similar values were obtained for metal contents between 8 ppm (cadmium) and 3300 ppm (zinc).

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

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


    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.

  5. Development of Environmentally Sustainable Methods for Treatment of Domestic Wastewater and Handling of Sewage Sludge on Yap Island

    Directory of Open Access Journals (Sweden)

    Joseph D. Rouse


    Full Text Available A survey was conducted of the wastewater treatment systems and related sludge handling practices on the island of Yap, in the Federated States of Micronesia, to assist in identifying areas where further work would be merited to improve on effectiveness and sustainability. A detailed inventory was made of communal septic tanks as found at health centers and schools. Though most of these septic tanks appeared to be functional, there were concerns due to some units being positioned within the tidal zone, covered over with vegetation, or out of reach of the pump truck. Furthermore, the centralized wastewater treatment plant on Yap provides only primary treatment consisting of a limited removal of suspended solids. Thus, only partially treated sewage is being discharged to the bay. Excess sludge is drawn from the treatment plant on a quarterly basis, which local farmers regularly make use of as fertilizer for crop application without adequate treatment. As an immediate target for further study and pilot testing, exploring the use of an attached-growth process as an inexpensive retrofit to enhance the effectiveness of the treatment plant is proposed. In addition, the benefits of implementing a composting program for recycle of waste sludge in a safe manner and developing a framework for management of septic tanks are discussed.

  6. [Performance and Factors Analysis of Sludge Dewatering in Different Wastewater Treatment Processes]. (United States)

    Liu, Ji-bao; Li, Ya-ming; Lü, Jian; Wei, Yuan-song; Yang, Min; Yu, Da-wei


    Sludge dewatering is one of the keys for sludge disposal and treatment of municipal wastewater treatment plants. In this study, the sludge dewaterability, flocculant consumption and costs of sludge dewatering for different wastewater treatment processes including A2/O and A2/O-MBR processes were analyzed, as well as the factors of sludge dewatering were analyzed by redundancy analysis (RDA) method, based on the data of one municipal wastewater treatment plant of Beijing in 2013. Results showed that both sludge dewaterability and flocculant consumption presented the seasonal variation, which means sludge dewatering was harder and coupled with higher flocculant consumption in the winter. Although the lower moisture content of dewatered sludge was obtained in the A2/O-MBR process (81.92% ± 1.64% ) compared with that in the A2/O process (82.56% ± 1.35%), the consumptions of flocculant [ (8.70 ± 7.25) kg x t(-1) DS] and electric energy (331.82 kW x h x t(-1) DS) in the A2/O-MBR process were higher than those in the A2/O process [(7.42 ± 2.96) kg x t(-1) DS, 121.57 kW x h x t(-1) DS for flocculant consumption and electric energy respectively], resulting in higher operation costs (RMB 204.76 yuan x t(-1) DS of flocculant consumption and RMB 231.61 yuan x t(-1) DS of energy consumption for the A2/O-MBR, RMB 175.00 yuan x t(-1) DS of flocculant consumption and RMB 84.86 yuan x t(-1) DS of energy consumption for the A2/O, respectively). Results of RDA showed that the seasonal variation of sludge dewaterability mainly depended on the content of organic matter in sludge which was related to the seasonal factors such as temperature, and was also impacted by the operating parameters such as SRT in wastewater treatment.

  7. Treatment of landfill leachate using an up-flow anaerobic sludge semi-fixed filter (United States)

    Hua, J.; Bai, S. Y.; Li, Z. Y.; Zhou, H. C.


    In the present work, an up-flow anaerobic sludge semi-fixed filter (UASSF) was developed for landfill leachate treatment by packing the soft polyurethane belt as the supporting carrier. The performance of the hybrid reactor was evaluated in terms of COD removal and carbon flux distribution, also, the biomass effectiveness was investigated by restarting the reactor without the supporting carrier. The COD removal increased with the stepwise increment of the organic loading rate (OLR), while the sulfate removal decreased slowly. When the reactor was operated at design load (9 kgCOD/m3·d), COD and sulfate removal remained around 81% and 90%, respectively. The results indicate that this kind of semi-fixed carrier is capable to form the active biofilm in the anaerobic process, and the UASSF system can perform well in the leachate treatment.

  8. Aerobic granular sludge inoculated microbial fuel cells for enhanced epoxy reactive diluent wastewater treatment. (United States)

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


    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Anaerobic Mesophilic and Thermophilic Treatment of Concentrated Latex Processing Wastewater in Two-Stage Upflow Anaerobic Sludge Blanket (UASB)


    , S. Jawjit; , W. Jawjit; , W. Liengcharernsit


    The objective of this study is to determine optimal conditions for operating the two-stage upflow anaerobic sludge blanket (UASB) used for treating wastewater from concentrated latex mills. Mesophilic and thermophilic conditions as well as hydraulic retention time (HRT), and pH were determined. Effect of NH3 on treatment inhibition was also investigated. The results indicated that mesophilic condition (35 0C) was an optimal temperature, whereas the pH of system should be controlled at 7 to pr...

  10. Full scale validation of helminth ova (Ascaris suum) inactivation by different sludge treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Paulsrud, B.; Gjerde, B.; Lundar, A.


    The Norwegian sewage sludge regulation requires disinfection (hygienisation) of all sludges for land application, and one of the criteria is that disinfected sludge should not contain viable helminth ova. All disinfection processes have to be designed and operated in order to comply with this criteria, and four processes employed in Norway (thermophilic aerobic pre-treatment, pre-pasteurisation, thermal vacuum drying in membrane filter presses and lime treatment) have been tested in full scale by inserting semipermeable bags of Ascaris suum eggs into the processes for certain limes. For lime treatment supplementary laboratory tests have been conducted. The paper presents the results of the experiments, and it could be concluded that all processes, except lime treatment, could be operated at less stringent time-temperature regimes than commonly experienced at Norwegian plants today. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uisung [Argonne National Lab. (ANL), Argonne, IL (United States); Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States); Urgun Demirtas, Meltem [Argonne National Lab. (ANL), Argonne, IL (United States); Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Tao, Ling [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    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

  12. Limitation of sludge biotic index application for control of a wastewater treatment plant working with shock organic and ammonium loadings. (United States)

    Drzewicki, Adam; Kulikowska, Dorota


    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. Copyright © 2011 Elsevier GmbH. All rights reserved.

  13. Recovery of Alum Coagulant from Water Treatment Plant Sludge: A Greener Approach for Water Purification


    Smita Joshi; Kriti Shrivastava


    The present work is based on Alum Recovery from the sludge obtained from Shyamala Water Treatment Plant by Acidic and Alkaline methods. In the acidic and alkaline method, the maximum recovery of alum coagulant is found to be 84.18% and 76.98% respectively. The recovered alum is as efficient as commercial alum and can be used again as coagulant for Water Treatment. This recovery can solve the vast problem of WTP (Water Treatment Plant) sludge management together with the problem of water pollu...

  14. Speciation evolution of zinc and copper during pyrolysis and hydrothermal carbonization treatments of sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Rixiang; Zhang, Bei; Saad, Emily M.; Ingall, Ellery D.; Tang, Yuanzhi


    Thermal and hydrothermal treatments are promising techniques for sewage sludge management that can potentially facilitate safe waste disposal, energy recovery, and nutrient recovery/recycling. Content and speciation of heavy metals in the treatment products affect the potential environmental risks upon sludge disposal and/or application of the treatment products. Therefore, it is important to study the speciation transformation of heavy metals and the effects of treatment conditions. By combining synchrotron X-ray spectroscopy/microscopy analysis and sequential chemical extraction, this study systematically characterized the speciation of Zn and Cu in municipal sewage sludges and their chars derived from pyrolysis (a representative thermal treatment technique) and hydrothermal carbonization (HTC; a representative hydrothermal treatment technique). Spectroscopy analysis revealed enhanced sulfidation of Zn and Cu by anaerobic digestion and HTC treatments, as compared to desulfidation by pyrolysis. Overall, changes in the chemical speciation and matrix properties led to reduced mobility of Zn and Cu in the treatment products. These results provide insights into the reaction mechanisms during pyrolysis and HTC treatments of sludges and can help evaluate the environmental/health risks associated with the metals in the treatment products.

  15. Exploring alternatives to reduce economical costs associated with FNA pre-treatment of waste activated sludge. (United States)

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


    Recent studies have shown the effectiveness of Free Nitrous Acid (FNA) pre-treatment in enhancing sludge biodegradability and improving its methane production potential. FNA is regarded as an environmental friendly pre-treatment which can be easily applied when a source of nitrite is present in wastewater treatment plants. However, when nitrite is not available and needs to be purchased, this treatment can become less attractive due to the costs associated to nitrite. In order to overcome this possible limitation, two different strategies to optimize the use of nitrite during FNA treatment were investigated: i) Recovering NO2(-) after the pre-treatment is completed; and ii) Concentrating the sludge before FNA pre-treatment. Results show that recovering NO2(-) from the pre-treated sludge is not suitable due to the loss of soluble organic matter present in the supernatant after the pre-treatment. However, concentrating the sludge before the pre-treatment seems a good strategy to optimize the use of nitrite. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Evaluation of the improvement of sonication pre-treatment in the anaerobic digestion of sewage sludge. (United States)

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


    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge. (United States)

    Huang, Hua-Jun; Yuan, Xing-Zhong


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Wastewater and sludge management and research in Oman: An overview. (United States)

    Jaffar Abdul Khaliq, Suaad; Ahmed, Mushtaque; Al-Wardy, Malik; Al-Busaidi, Ahmed; Choudri, B S


    It is well recognized that management of wastewater and sludge is a critical environmental issue in many countries. Wastewater treatment and sludge production take place under different technical, economic, and social contexts, thus requiring different approaches and involving different solutions. In most cases, a regular and environmentally safe wastewater treatment and associated sludge management requires the development of realistic and enforceable regulations, as well as treatment systems appropriate to local circumstances. The main objective of this paper is to provide useful information about the current wastewater and sludge treatment, management, regulations, and research in Oman. Based on the review and discussion, the wastewater treatment and sludge management in Oman has been evolving over the years. Further, the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman. Wastewater treatment and sludge management in Oman have been evolving over the years. Sludge utilization has been a challenge due to its association with human waste. Therefore, composting of sewage sludge is the best option in agriculture activities. Sludge and wastewater utilization can add up positively in the economic aspects of the country in terms of creating jobs and improving annual income rate. The number of research projects done on wastewater reuse and other ongoing ones related to the land application of sewage sludge should encourage revision of existing standards, regulations, and policies for the management and beneficial use of sewage sludge in Oman.

  19. Microbiological characterization and specific methanogenic activity of anaerobe sludges used in urban solid waste treatment. (United States)

    Lozano, Claudia Johanna Sandoval; Mendoza, Marisol Vergara; de Arango, Mariela Carreño; Monroy, Edgar Fernando Castillo


    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(4) and CO(2)) and an effluent that can be used as biofertilizer. The system was inoculated with sludge from a wastewater treatment plant (WWTP) (Río Frío 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(-1) and a concentration of CO(2) of 90%. In this reactor, the fermentative population was predominant (10(5)-10(6)MPN mL(-1)). The acetogenic population was (10(5)MPN mL(-1)) and the sulphate-reducing population was (10(4)-10(5)MPN mL(-1)). In the methanogenic reactor (R2), levels of CH(4) (70%) were higher than CO(2) (25%), whereas the VFA values were lower than 4000 mg L(-1). Substrate competition between sulphate-reducing (10(4)-10(5)MPN mL(-1)) and methanogenic bacteria (10(5)MPN mL(-1)) was not detected. From the SMA results obtained, acetoclastic (2.39 g COD-CH(4)g(-1)VSS(-1)day(-1)) and hydrogenophilic (0.94 g COD-CH(4)g(-1)VSS(-1)day(-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.

  20. Sludge granulation during anaerobic treatment of pre-hydrolysed ...

    African Journals Online (AJOL)

    Prior to entering the digester, the influent was supplemented with sucrose, which increased the total and soluble COD by 300 mg/l. An upflow anaerobic sludge bed (UASB) digester was operated at different hydraulic retention times (HRT) ranging from 26.7 h to 2.2 h, while the organic load rate (OLR) ranged from 0.9 to 7.3 ...

  1. Wastewater sludges pretreated by different oxidation systems at mild conditions to promote the biogas formation in anaerobic processes. (United States)

    Segura, Y; Puyol, D; Ballesteros, L; Martínez, F; Melero, J A


    The effect of different oxidation processes at mild conditions including the coupled-Fenton (sono-Fenton, photo-Fenton, and sono-photo-Fenton) and their blank systems (ultrasound, ultraviolet, zero valent iron, and Fenton) on anaerobic digestion of the sludge for biogas production was investigated. Ultrasounds led to the highest organic matter solubilization (3.8 up to 5.2 g chemical oxygen demand (COD)/L, for the raw and treated sludge, respectively), while for the rest, organic matter transformation was observed resulting in an almost soluble COD net balance. Results indicated that for the most oxidative processes, the released organic matter was probably mineralized by the hydroxyl radicals produced during the treatments. It is interesting to remark that even if the biochemical methane potential was barely enhanced by the different methods applied, all the methods demonstrated to enhance the overall kinetics of the biomethanation processes, increasing the rapidly biodegradable fraction of the sludge.

  2. Enhancement of anaerobic digestion efficiency of wastewater sludge and olive waste: Synergistic effect of co-digestion and ultrasonic/microwave sludge pre-treatment. (United States)

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


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. Effect of pre-treatment at elevated temperature

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Yenal, U.; Skiadas, Ioannis V.


    Anaerobic digestion is an appropriate technique for the treatment of sludge before final disposal and it is employed worldwide as the oldest and most important process for sludge stabilization. In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic...... between mesophilic and thermophilic anaerobic digestion of sludge and (b) the effect of the pretreatment at 70 degreesC on mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. The pretreatment step showed very positive effect on the methane potential and production rate upon...... digestion. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization, enhancement of dewatering of the sludge, reduction of the numbers of pathogens and could be realized at relatively low cost especially at low temperatures. The present study investigates (a) the differences...

  4. The production of sludge in anaerobic purification treatments; Produccion de fangos en la depuracion anaerobica

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E. del R.; Mejia Sanchez, G.M. [Departamento de Ingenieria Ambiental, Facultad de Ingenieria, Universidad Autonoma de Yucatan (Mexico)


    One of the characteristics of anaerobic processes is the low level of sludge production. However it is important to maintain a certain concentration of biomass in the system to ensure sufficient removal of organic matter. As organic matter degrades, part of it is transformed into gas while the rest remains in the system as biomass, it is important to control the concentration of sludge in the system as a way of enchaincing process efficiency. The quality of sludge produced during the anaerobic digestion process is related to the amount of substrate consumed and the amount of gas generated and particularly to the concentration of volatile suspended solids (active biomass). nevertheless, the operating conditions of the digester can modify the distribution of the results of the bacterial metabolism. The present study examines the influence of hydraulic resistance time, organic, load and substrate concentration on sludge production and the relation between sludge production and the amount of substrate consumed by the system for each set of cinditions. The findings were obtained from a experiment in which a modified UASB digester was operated with a slow mixing system. (Author) 7 refs.

  5. Degradation of naproxen and carbamazepine in spiked sludge by slurry and solid-phase Trametes versicolor systems. (United States)

    Rodríguez-Rodríguez, Carlos E; Marco-Urrea, Ernest; Caminal, Gloria


    Growth and activity of the white-rot fungus Trametes versicolor on sewage sludge were assessed in bioslurry and solid-phase systems. Bioslurry cultures with different loads of sludge (10%, 25% and 38%, w/v) were performed. A lag phase of at least 2 d appeared in the 25 and 38%-cultures, however, the total fungal biomass was higher for the latter and lower for the 10%-culture after 30 d, as revealed by ergosterol determination. Detectable laccase activity levels were found in the 10 and 25%-cultures (up to 1308 and 2588 AUL(-1), respectively) while it was negligible in the 38%-culture. Important levels of ergosterol and laccase were obtained over a 60 d period in sludge solid-phase cultures amended with different concentrations of wheat straw pellets as lignocellulosic bulking material. Degradation experiments in 25%-bioslurry cultures spiked with naproxene (NAP, analgesic) and carbamazepine (CBZ, antiepileptic) showed depletion of around 47% and 57% within 24h, respectively. Complete depletion of NAP and around 48% for CBZ were achieved within 72 h in sludge solid cultures with 38% bulking material. CBZ degradation is especially remarkable due to its high persistence in wastewater treatment plants. Results showed that T. versicolor may be an interesting bioremediation agent for elimination of emerging pollutants in sewage sludge. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Removal of Pb2+ and Ni2+ by bio-sludge in sequencing batch reactor (SBR) and granular activated carbon-SBR (GAC-SBR) systems. (United States)

    Sirianuntapiboon, Suntud; Ungkaprasatcha, Ongorn


    Living bio-sludge from domestic wastewater treatment plant was used as adsorbent of heavy metals (Pb(2+), Ni(2+)) and its adsorption capacity was about 10-30% reduced by autoclaving at 110 degrees C for 10 min. The living bio-sludge acclimatized in synthetic industrial estate wastewater (SIEWW) without heavy metals showed the highest Pb(2+) and Ni(2+) adsorption capacities at 840+/-20 and 720+/-10 mg/g bio-sludge, respectively. The adsorbed Pb(2+) and Ni(2+) were easily eluted (70-77%) from bio-sludge by washing with 0.1 mol/l HNO(3) solution. The heavy metals (Pb(2+), Ni(2+)) removal efficiency of both SBR and GAC-SBR systems were increased with the increase of hydraulic retention time (HRT), or the decrease of organic loading. The SBR system showed higher heavy metals removal efficiency than GAC-SBR system at the same organic loading or HRT. The Pb(2+), Ni(2+), BOD(5), COD and TKN removal efficiencies of GAC-SBR system were 88.6+/-0.9%, 94.6+/-0.1%, 91.3+/-1.0%, 81.9+/-1.0% and 62.9+/-0.5%, respectively with industrial estate wastewater (IEWW) with 410 mg/l glucose, 5 mg/l Pb(2+) and 5 mg/l Ni(2+) under organic loading of 1.25 kg BOD(5)/m(3) d (HRT of 3 days). The bio-sludge quality (sludge volume index: SVI) of the system was less than 80 ml/g. The excess sludge from both SBR and GAC-SBR systems with SIEWW under the organic loading of 1.25-2.50 kg BOD(5)/m(3) d contained Pb(2+) and Ni(2+) at concentrations of 240-250 mg Pb(2+)/g bio-sludge and 180-210 mg Ni(2+)/g bio-sludge, respectively.


    Directory of Open Access Journals (Sweden)

    Anna Iżewska


    Full Text Available Pomorzany Sewage Treatment Plant in Szczecin ensures the required parameters of treated sewage. However, due to higher efficiency of sewage treatment, more sludge is produced after the treatment process. In the examined sludge treatment plant, primary sludge is gravitationally thickened to the content of about 5% of dry matter, and the excessive is thickened in mechanical compactors up to 6% of dry matter. Settlements preliminary and excessive after compaction is discharged to the sludge tank where a pump is forced into two closed digesters. Each digester has the capacity of 5069 m3. At a temperature of about 37 °C a mesophilic digestion is performed. Biogas, that is produced in the chamber, is stored in two-coat tanks with the capacity of 1500 m3 each and after desulphurization with the biosulfex method (which results with obtaining elemental sulphur it is used as fuel in cogeneration units. The aim of this study was to determine amount of energy given by sewage sludge in the form of heat during the process of methane digestion (primary and excessive. These amounts were determined on the basis of chemical energy balance of sewage carried into and out of Separate Sludge Digesters and produced biogas within 24h. The study determined that the percentage value of average chemical energy amount turned into heat and discharged with produced methane in relation to chemical energy of sewage carried into the first digester in Pomorzany Treatment Plant in Szczecin was in the range of 47.86 ± 9.73% for a confidence level of 0.95. On average 80.86 ± 33.65% was emitted with methane and 19.14 ± 33.65% of energy was changed into heat.

  8. Fractions composition study of the pyrolysis oil obtained from sewage sludge treatment plant. (United States)

    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


    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)). Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China


    Baoling Duan; Fenwu Liu; Wuping Zhang; Haixia Zheng; Qiang Zhang; Xiaomei Li; Yushan Bu


    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 c...

  10. Development of effluent removal prediction model efficiency in septic sludge treatment plant through clonal selection algorithm. (United States)

    Ting, Sie Chun; Ismail, A R; Malek, M A


    This study aims at developing a novel effluent removal management tool for septic sludge treatment plants (SSTP) using a clonal selection algorithm (CSA). The proposed CSA articulates the idea of utilizing an artificial immune system (AIS) to identify the behaviour of the SSTP, that is, using a sequence batch reactor (SBR) technology for treatment processes. The novelty of this study is the development of a predictive SSTP model for effluent discharge adopting the human immune system. Septic sludge from the individual septic tanks and package plants will be desuldged and treated in SSTP before discharging the wastewater into a waterway. The Borneo Island of Sarawak is selected as the case study. Currently, there are only two SSTPs in Sarawak, namely the Matang SSTP and the Sibu SSTP, and they are both using SBR technology. Monthly effluent discharges from 2007 to 2011 in the Matang SSTP are used in this study. Cross-validation is performed using data from the Sibu SSTP from April 2011 to July 2012. Both chemical oxygen demand (COD) and total suspended solids (TSS) in the effluent were analysed in this study. The model was validated and tested before forecasting the future effluent performance. The CSA-based SSTP model was simulated using MATLAB 7.10. The root mean square error (RMSE), mean absolute percentage error (MAPE), and correction coefficient (R) were used as performance indexes. In this study, it was found that the proposed prediction model was successful up to 84 months for the COD and 109 months for the TSS. In conclusion, the proposed CSA-based SSTP prediction model is indeed beneficial as an engineering tool to forecast the long-run performance of the SSTP and in turn, prevents infringement of future environmental balance in other towns in Sarawak. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Biodegradation of benzotriazoles and hydroxy-benzothiazole in wastewater by activated sludge and moving bed biofilm reactor systems

    DEFF Research Database (Denmark)

    Mazioti, Aikaterini A.; Stasinakis, Athanasios S.; Pantazi, Ypapanti


    Two laboratory scale fully aerated continuous flow wastewater treatment systems were used to compare the removal of five benzotriazoles and one benzothiazole by suspended and attached growth biomass. The Activated Sludge system was operated under low organic loading conditions. The Moving Bed Bio...... biomass grown in different bioreactors of MBBR systems were also observed. Batch experiments showed that micropollutants biodegradation by both types of biomass is co-metabolic....

  12. Ozonation and Thermal Pre-Treatment of Municipal Sewage Sludge-Implications for Toxicity and Methane Potential

    DEFF Research Database (Denmark)

    Davidsson, A.; Eriksson, Eva; Fick, J.


    The aim of this study was to determine effects on methane potential and overall sludge quality from two different sludge pre-treatment technologies (ozonation high/low dosage and thermal treatment 55/70 degrees C). In general both treatments produced increased methane potential. Thermal treatment...... resulted in higher chemical oxygen demand (COD)-solubilisation, while the highest volatile fatty acids (VFA) increase was obtained with ozonation. Sludges had inhibiting effects in a barley seed germination assay and a yeast oestrogen screen both before and after pre-treatment, but inhibition was reduced...... by ozone treatment and digestion. No statistical significant reduction in concentrations of included pharmaceuticals could be observed....

  13. Acidified and ultrafiltered recovered coagulants from water treatment works sludge for removal of phosphorus from wastewater. (United States)

    Keeley, James; Smith, Andrea D; Judd, Simon J; Jarvis, Peter


    This study used a range of treated water treatment works sludge options for the removal of phosphorus (P) from primary wastewater. These options included the application of ultrafiltration for recovery of the coagulant from the sludge. The treatment performance and whole life cost (WLC) of the various recovered coagulant (RC) configurations have been considered in relation to fresh ferric sulphate (FFS). Pre-treatment of the sludge with acid followed by removal of organic and particulate contaminants using a 2kD ultrafiltration membrane resulted in a reusable coagulant that closely matched the performance FFS. Unacidified RC showed 53% of the phosphorus removal efficiency of FFS, at a dose of 20 mg/L as Fe and a contact time of 90 min. A longer contact time of 8 h improved performance to 85% of FFS. P removal at the shorter contact time improved to 88% relative to FFS by pre-acidifying the sludge to pH 2, using an acid molar ratio of 5.2:1 mol H(+):Fe. Analysis of the removal of P showed that rapid phosphate precipitation accounted for >65% of removal with FFS. However, for the acidified RC a slower adsorption mechanism dominated; this was accelerated at a lower pH. A cost-benefit analysis showed that relative to dosing FFS and disposing waterworks sludge to land, the 20 year WLC was halved by transporting acidified or unacidified sludge up to 80 km for reuse in wastewater treatment. A maximum inter-site distance was determined to be 240 km above the current disposal route at current prices. Further savings could be made if longer contact times were available to allow greater P removal with unacidified RC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Modified anaerobic digestion elutriated phased treatment for the anaerobic co-digestion of sewage sludge and food wastewater. (United States)

    Mo, Kyung; Lee, Wonbae; Kim, Moonil


    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.

  15. Speciation Dynamics of Phosphorus during (Hydro)Thermal Treatments of Sewage Sludge. (United States)

    Huang, Rixiang; Tang, Yuanzhi


    (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.

  16. Evaluation Of FWENC Process For Treatment Of MVST Sludges, Supernates, And Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Barton, JW


    In 1998, the Foster Wheeler Environmental Corporation (FWENC) was awarded an 11-year contract to treat transuranic waste at the Oak Ridge National Laboratory, including Melton Valley Storage Tank (MVST) waste. Their baseline tank waste process consists of: (1) Separating the supernate from the sludge, (2) Washing the sludge with water and adding this wash water to the supernate, (3) Stabilizing the supernate/wash water or the washed sludge with additives if either are projected to fail Resource Conservation Recovery Act (RCRA) Toxic Characteristics Leaching Protocol (TCLP) criteria, and (4) Stabilizing both the washed sludge and supernate/wash water by vacuum evaporation. An ''Optimum'' treatment procedure consisted of adding a specified quantity of two stabilizers--ThioRed{reg_sign} and ET Soil Polymer{reg_sign}--and an ''Alternate'' treatment simply increased the amount of ThioRed{reg_sign} added. This report presents the results of a study funded by the Tanks Focus Area (TFA) to provide Oak Ridge Operations (ORO) with independent laboratory data on the performance of the baseline process for treating the sludges, including washing the sludge and treating the wash water (although supernates were not included in the wash water tests). Two surrogate and seven actual tank wastes were used in this evaluation. Surrogate work, as well as the initial work with actual tank sludge, was based on an existing sludge sample from Bethel Valley Evaporator Storage Tank (BVEST) W23. One surrogate was required to be based on a surrogate previously developed to mimic the weighted average chemical composition of the MVST-BVEST using a simple mix of reagent grade chemicals and water, called the ''Quick and Dirty'' surrogate (QnD). The composition of this surrogate was adjusted toward the measured composition of W23 samples. The other surrogate was prepared to be more representative of the W23 sludge sample by precipitation

  17. Energy potential and alternative usages of biogas and sludge from UASB reactors: case study of the Laboreaux wastewater treatment plant. (United States)

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


    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.

  18. Efficient Phosphorus Cycling in Food Production: Predicting the Phosphorus Fertilization Effect of Sludge from Chemical Wastewater Treatment. (United States)

    Falk Øgaard, Anne; Brod, Eva


    This study examined the P fertilization effects of 11 sewage sludges obtained from sewage treated with Al and/or Fe salts to remove P by a pot experiment with ryegrass (Lolium multiflorum) and a nutrient-deficient sand-peat mixture. Also it investigated whether fertilization effects could be predicted by chemical sludge characteristics and/or by P extraction. The mineral fertilizer equivalent (MFE) value varied significantly but was low for all sludges. MFE was best predicted by a negative correlation with ox-Al and ox-Fe in sludge, or by a positive correlation with P extracted with 2% citric acid. Ox-Al had a greater negative impact on MFE than ox-Fe, indicating that Fe salts are preferable as a coagulant when aiming to increase the plant availability of P in sludge. The results also indicate that sludge liming after chemical wastewater treatment with Al and/or Fe salts increases the P fertilization effect.

  19. Comparison of bioindicator eukaryotes of activated sludge biocenoses on two water-treatment plants: a case study

    Directory of Open Access Journals (Sweden)

    Achmadulina Farida Y.


    Full Text Available Activated sludge biocenoses were compared on waste-water treatment plants in the city of Kazan, Russian Federation and the city of Teplice, Czech Republic. Based on Palia-Kovnatski index, Acanthamoeba in Kazan, Epistylis in Teplice, and Acanthamoeba and Centropyxis were dominant genera in both plants. The major subdominant generas identified were Arcella, Opercularia and Aspidisca. This indicates high nitrification ability, high water purification potential and matured activated sludge. Chemical composition of the waste-water was identified as the main factor determining the sludge biocenoses diversity. Higher sludge biodiversity (Shannon, Margalef, and Sorensen indexes was found in Kazan corresponding to more concentrated inflow water.

  20. Continuous sulfidogenic wastewater treatment with iron sulfide sludge oxidation and recycle. (United States)

    Deng, Dongyang; Lin, Lian-Shin


    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 FeS 2 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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Fate of organic matter during moderate heat treatment of sludge: kinetics of biopolymer and hydrolytic activity release and impact on sludge reduction by anaerobic digestion. (United States)

    Lefebvre, D; Dossat-Létisse, V; Lefebvre, X; Girbal-Neuhauser, E


    Temperature-phased anaerobic digestion with a 50-70 °C pre-treatment is widely proposed for sludge. Here, such a sludge pre-treatment (65 °C) was studied against the physical, enzymatic and biodegradation processes. The soluble and particulate fractions were analysed in terms of biochemical composition and hydrolytic enzymatic activities. Two kinetics of organic matter solubilisation were observed: a rapid transfer of the weak-linked biopolymers to the water phase, including sugars, proteins or humic acid-like substances, to the water phase, followed by a slow and long-term solubilisation of proteins and humic acid-like substances. In addition, during the heat treatment a significant pool of thermostable hydrolytic enzymes including proteases, lipases and glucosidases remains active. Consequently, a global impact on organic matter was the transfer of the biodegradable chemical oxygen demand (COD) from the particulate to the soluble fraction as evaluated by the biological methane potential test. However, the total biodegradable COD content of the treated sludge remained constant. The heat process improves the bio-accessibility of the biodegradable molecules but doesn't increase the inherent sludge biodegradability, suggesting that the chemistry of the refractory proteins and humic acids seems to be the real limit to sludge digestion.

  2. Composting. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook. (United States)

    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…

  3. The agricultural use of water treatment plant sludge: pathogens and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Ignacio Nadal Rocamora


    Full Text Available The use of water treatment plant sludge to restore degraded soils is customary agricultural practice, but it could be dangerous from the point of view of both health and the environment. A transient increase of either pathogenic or indicator microbial populations, whose persistence in time is variable and attributed to the characteristics of the soil (types of materials in the soil, any amendments (origin and treatments it has undergone or the weather (humidity and temperature mainly, has often been detected in soils treated with this kind of waste. Given their origin, water treatment plant sludges could lead to the transmission of a pathogens and b antibiotic-resistant microorganisms to human beings through the food chain and cause the spreading of antibiotic resistances as a result of their increase and persistence in the soil for variable periods of time. However, Spanish legislation regulating the use of sludges in the farming industry is based on a very restricted microbiological criterion. Thus, we believe better parameters should be established to appropriately inform of the state of health of soils treated with water treatment plant sludge, including aspects which are not presently assessed such as antibiotic resistance.

  4. The anaerobic treatment of low-strength brewery wastewater in expanded granular sludge bed

    NARCIS (Netherlands)

    Kato, M.T.; Rebac, S.; Lettinga, G.


    Anaerobic treatment of low-strength brewery wastewater, with influent total chemical oxygen demand (COD) (COD(in)) concentrations ranging from 550 to 825 mg/L, was investigated in a pilot-scale 225.5-L expanded granular sludge bed (EGSB) reactor. In an experiment in which the temperature was lowered

  5. Effects of graphite nanoparticles on nitrification in an activated sludge system. (United States)

    Dong, Qian; Liu, Yanchen; Shi, Hanchang; Huang, Xia


    Graphite nanoparticles (GNPs) might result in unexpected effects during their transportation and transformation in wastewater treatment systems, including strong thermo-catalytic and catalytic effects and microbial cytotoxicity. In particular, the effects of GNPs on the nitrification process in activated sludge systems should be addressed. This study aimed to estimate the influence of GNPs on the nitrification process in a short-term nitrification reactor with exposure to different light sources. The results indicated that GNPs could only improve the efficiency of photothermal transformation slightly in the activated sludge system because of its photothermal effects under the standard illuminant (imitating 1 × sun). However, even with better photothermal effects, the nitrification efficiency still decreased significantly with GNP dosing under the standard illuminant, which might result from stronger cytotoxic effects of GNPs on the nitrifying bacteria. The disappearance of extracellular polymeric substances (EPS) around bacterial cells was observed, and the total quantity of viable bacteria decreased significantly after GNP exposuring. Variation in bacterial groups primarily occurred in nitrifying microbial communities, including Nitrosomonas sp., Nitrosospira sp., Comamonas sp. and Bradyrhizobiace sp. Nitrifiers significantly decreased, while the phyla Gammaproteobacteria, Deinocccus, and Bacteroidetes exhibited greater stability during GNP treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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


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

  7. Occurrence of bisphenol A in wastewater and wastewater sludge of CUQ treatment plant

    Directory of Open Access Journals (Sweden)

    Dipti Prakash Mohapatra


    Full Text Available The identification and quantification of bisphenol A (BPA in wastewater (WW and wastewater sludge (WWS is of major interest to assess the endocrine activity of treated effluent discharged into the environment. BPA is manufactured in high quantities fro its use in adhesives, powder paints, thermal paper and paper coatings among others. Due to the daily use of these products, high concentration of BPA was observed in WW and WWS. BPA was measured in samples from Urban Community of Quebec wastewater treatment plant located in Quebec (Canada using LC-MS/MS method. The results showed that BPA was present in significant quantities (0.07 μg L–1 to 1.68 μg L–1 in wastewater and 0.104 μg g–1 to 0.312 μg g–1 in wastewater sludge in the wastewater treatment plant (WWTP. The treatment plant is efficient (76 % in removal of pollutant from process stream, however, environmentally significant concentrations of 0.41 μg L–1 were still present in the treated effluent. Rheological study established the partitioning of BPA within the treatment plant. This serves as the base to judge the portion of the process stream requiring more treatment for degradation of BPA and also in selection of different treatment methods. Higher BPA concentration was observed in primary and secondary sludge solids (0.36 and 0.24 μg g–1, respectively as compared to their liquid counterpart (0.27 and 0.15 μg L–1, respectively separated by centrifugation. Thus, BPA was present in significant concentrations in the WWTP and mostly partitioned in the solid fraction of sludge (Partition coefficient (Kd for primary, secondary and mixed sludge was 0.013, 0.015 and 0.012, respectively.

  8. Phosphorus removal by acid mine drainage sludge from secondary effluents of municipal wastewater treatment plants. (United States)

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


    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.

  9. Monitoring and troubleshooting of non-filamentous settling and dewatering problems in an industrial activated sludge treatment plant

    DEFF Research Database (Denmark)

    Kjellerup, B. V.; Keiding, Kristian; Nielsen, Per Halkjær


    A large industrial activated sludge wastewater treatment plant had temporary problems with settling and dewatering of the sludge. Microscopical investigations revealed that the poor settling properties were not due to presence of filamentous bacteria, but poor floc properties. In order to charact......A large industrial activated sludge wastewater treatment plant had temporary problems with settling and dewatering of the sludge. Microscopical investigations revealed that the poor settling properties were not due to presence of filamentous bacteria, but poor floc properties. In order...... dewaterability. The monitoring program revealed that a deterioration of the floc strength and the settling properties in the process tanks was closely connected to downstream dewatering problems and poor effluent quality. Particularly severe problems were observed a few weeks after the production at the factory...... at this industrial plant. The described strategy can be useful in general to find and solve many solid/liquid separation problems in activated sludge wastewater treatment plants....

  10. Heavy metals in a degraded soil treated with sludge from water treatment plant

    Directory of Open Access Journals (Sweden)

    Teixeira Sandra Tereza


    Full Text Available The application of water treatment sludge (WTS to degraded soil is an alternative for both residue disposal and degraded soil reclaim. This study evaluated effects of the application of water treatment sludge to a Typic Hapludox soil degraded by tin mining in the National Forest of Jamari, State of Rondonia, Brazil, on the content of heavy metals. A completely randomized experimental design with five treatments was used: control (n = 4; chemical control, which received only liming (n = 4; and rates D100, D150 and D200, which corresponded to 100, 150 and 200 mg of N-sludge kg-1 soil (n = 20, respectively. Thirty days after liming, period in which soil moisture was kept at 70% of the retention capacity, soil samples were taken and analyzed for total and extractable Fe, Cu, Mn, Zn, Cd, Pb, Ni, and Cr. The application of WTS increased heavy-metal contents in the degraded soil. Although heavy metals were below their respective critical limits, sludge application onto degraded areas may cause hazardous environmental impact and thus must be monitored.

  11. 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. (United States)

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


    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 (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 abiotic transformation (complete or with metabolites production), bound residues formation. In addition, data on sludge liquors - centrifuged (CW) and condensed (TDW) waters

  12. Communities of ammonia-oxidizing bacteria in activated sludge of various sewage treatment plants in Tokyo. (United States)

    Limpiyakorn, Tawan; Shinohara, Yuko; Kurisu, Futoshi; Yagi, Osami


    We investigated ammonia-oxidizing bacteria in activated sludge collected from 12 sewage treatment systems, whose ammonia removal and treatment processes differed, during three different seasons. We used real-time PCR quantification to reveal total bacterial numbers and total ammonia oxidizer numbers, and used specific PCR followed by denaturing gel gradient electrophoresis, cloning, and sequencing of 16S rRNA genes to analyze ammonia-oxidizing bacterial communities. Total bacterial numbers and total ammonia oxidizer numbers were in the range of 1.6 x 10(12) - 2.4 x 10(13) and 1.0 x 10(9) - 9.2 x 10(10)cellsl(-1), respectively. Seasonal variation was observed in the total ammonia oxidizer numbers, but not in the ammonia-oxidizing bacterial communities. Members of the Nitrosomonas oligotropha cluster were found in all samples, and most sequences within this cluster grouped within two of the four sequence types identified. Members of the clusters of Nitrosomonas europaea-Nitrosococcus mobilis, Nitrosomonas cryotolerans, and unknown Nitrosomonas, occurred solely in one anaerobic/anoxic/aerobic (A2O) system. Members of the Nitrosomonas communis cluster occurred almost exclusively in association with A2O and anaerobic/aerobic systems. Solid residence time mainly influenced the total numbers of ammonia-oxidizing bacteria, whereas dissolved oxygen concentration primarily affected the ammonia-oxidizing activity per ammonia oxidizer cell.

  13. Stabilization and dewatering of wastewater treatment plants sludge using the Fenton process

    Directory of Open Access Journals (Sweden)

    Abolfazl Azhdarpoor


    Full Text Available Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF, volatile organic compounds (VSS, total suspended solids (TSS, soluble chemical oxygen demand (SCOD and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9, hydrogen peroxide (0.015- 0.18mol/L, Fe2+ (0.008- 0.1mol/L and time (5 - 60 minutes for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering.

  14. Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants. (United States)

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


    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 m3/d, 90-100 m3/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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The influence of amendment material on biosolid composting of sludge from a waste-water treatment plant

    Directory of Open Access Journals (Sweden)

    Patricia Torres Lozada


    Full Text Available Aerobic composting employing manual turning was evaluated by using the sludge produced by EMCALI EICE ESP's Cañaverlejo wastewater treatment plant (PTAR-C. Compost (in 1,0 ton piles consisted of sludge, a fixed proportion of bulking agent (10% and amendment material. Sugarcane waste and solid organic (marketplace waste were evaluated as amendment material using 20/80 and 40/60 weight/weight (amendment/sludge ratios. Incorporating the amendment material improved the compost, being reflected in a faster start for the thermophilic phase, higher temperatures beign maintained (>55°C and better C/N ratio obtained in the compost in all treatments compared to the pile which had no amendment added to it. Incorporating the bulking agent improved sludge manageability during composting; the best combination was 54% sludge + 10% sugacane bagasse + 36% liquid sugarcane waste.

  16. Assessment of a sewage sludge treatment on cadmium, copper and zinc bioavailability in barley, ryegrass and earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, Agnes Y. [Sanexen Environmental Services Inc., 1471 Lionel-Boulet Boulevard, Varennes, Quebec J3X 1P7 (Canada)]. E-mail:; Rocheleau, Sylvie [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Sarrazin, Manon [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Sunahara, Geoffrey I. [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada)]. E-mail:; Blais, Jean-Francois [Institut national de la recherche scientifique (INRS-ETE), Centre Eau, Terre et Environnement, 490 rue de la Couronne street, Quebec, Quebec G1K 9A9 (Canada)]. E-mail:


    The toxicity and bioavailability of metals were assessed to verify the efficiency of a new chemical leaching process (METIX-AC) to minimize the risk of metals found in municipal sewage sludge. For this purpose, sludge samples were spiked with cadmium, copper and/or zinc before being treated using METIX-AC. The sludge decontamination resulted in a removal of spiked metals (79-89%), in a decrease of the more labile fractions, and in a corresponding increase of the residual fraction. The toxicity observed after exposure of two plant species, barley (Hordeum vulgare) and ryegrass (Lolium perenne), and a terrestrial invertebrate, Eisenia andrei, to sludge-soil mixtures, disappeared after treatment, although the adverse effects were minor before treatment. The sludge treatment also significantly decreased the bioaccumulation of cadmium, copper, and zinc in the exposed species. For cadmium, maximum tissue concentrations of 0.45 {+-} 0.08 mg/kg in barley, 0.79 {+-} 0.27 mg/kg in ryegrass, and 21.82 {+-} 1.85 mg/kg in earthworm exposed to sludge before treatment decreased after treatment to values similar to those observed with negative controls. - Assessment of a sewage sludge treatment on metal bioavailability as measured by metal speciation, toxicity and bioaccumulation.

  17. Energy self-sufficient sewage wastewater treatment plants: is optimized anaerobic sludge digestion the key? (United States)

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


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

  18. Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan. (United States)

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


    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. Removal of aluminum from drinking water treatment sludge using vacuum electrokinetic technology. (United States)

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


    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mass and energy balances of sludge processing in reference and upgraded wastewater treatment plants. (United States)

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


    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.

  1. Liquid products from oxidative thermal treatment of oil sludge with different oxygen concentrations of air. (United States)

    Shie, J L; Chang, C Y; Lin, J P; Le, D J; Wu, C H


    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

  2. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas)

    Energy Technology Data Exchange (ETDEWEB)

    Escolà Casas, Mònica [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark); Chhetri, Ravi Kumar [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Ooi, Gordon [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark); Hansen, Kamilla M.S. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Litty, Klaus [Department of Chemistry and Biotechnology, Danish Technological Institute, Kongsvang Allé 29, 8000 Aarhus C (Denmark); Christensson, Magnus [AnoxKaldnes, Klosterängsvägen 11A, 226 47 Lund (Sweden); Kragelund, Caroline [Department of Chemistry and Biotechnology, Danish Technological Institute, Kongsvang Allé 29, 8000 Aarhus C (Denmark); Andersen, Henrik R. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Bester, Kai, E-mail: [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark)


    Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process (hybrid biofilm and activated sludge system (Hybas™)) has been suggested as a possible solution for hospital wastewater treatment. To investigate the potential of such a hybrid system for the removal of pharmaceuticals in hospital wastewater a pilot plant consisting of a series of one activated sludge reactor, two Hybas™ reactors and one moving bed biofilm reactor (MBBR) has been established and adapted during 10 months of continuous operation. After this adaption phase batch and continuous experiments were performed for the determination of degradation of pharmaceuticals. Removal of organic matter and nitrification mainly occurred in the first reactor. Most pharmaceuticals were removed significantly. The removal of pharmaceuticals (including X-ray contrast media, β-blockers, analgesics and antibiotics) was fitted to a single first-order kinetics degradation function, giving degradation rate constants from 0 to 1.49 h{sup −1}, from 0 to 7.78 × 10{sup −1} h{sup −1}, from 0 to 7.86 × 10{sup −1} h{sup −1} and from 0 to 1.07 × 10{sup −1} h{sup −1} for first, second, third and fourth reactors respectively. Generally, the highest removal rate constants were found in the first and third reactors while the lowest were found in the second one. When the removal rate constants were normalized to biomass amount, the last reactor (biofilm only) appeared to have the most effective biomass in respect to removing pharmaceuticals. In the batch experiment, out of 26 compounds, 16 were assessed to degrade more than 20% of the respective pharmaceutical within the Hybas™ train. In the continuous flow experiments, the measured removals were similar to those estimated from the batch experiments, but the concentrations of a few pharmaceuticals appeared to increase

  3. Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants? (United States)

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


    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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Davood Nourmohammadi


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

  5. Aeration optimization through operation at low dissolved oxygen concentrations: Evaluation of oxygen mass transfer dynamics in different activated sludge systems. (United States)

    Fan, Haitao; Qi, Lu; Liu, Guoqiang; Zhang, Yuankai; Fan, Qiang; Wang, Hongchen


    In wastewater treatment plants (WWTPs) using the activated sludge process, two methods are widely used to improve aeration efficiency - use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics (such as concentrations of mixed liquor suspended solids (MLSS) and microbial communities) and operating conditions (such as air flow rate and operational dissolved oxygen (DO) concentrations). Moreover, operational DO is closely linked to effluent quality. This study, which is in reference to WWTP discharge class A Chinese standard effluent criteria, determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model (determined using different air flow rate (Q' air ) and mixed liquor volatile suspended solids (MLVSS) values), theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however, operating at low DO and low MLVSS could significantly reduce energy consumption. Finally, a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed, which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology. Copyright © 2016. Published by Elsevier B.V.

  6. Winery wastewater treatment by heterogeneous Photo-Fenton process and activated sludges; Depuracion de efluentes vinicolas ediante tratamientos Foto-Fenton en fase heterogenea y lodos activos

    Energy Technology Data Exchange (ETDEWEB)

    Mosteo, R.; Lalinde, N.; Ormad, Maria O. M.; Ovelleiro, J. L.


    The system composed by heterogeneous Photon-Fenton assisted by solar light and biological treatment based on activated sludge process treats adequately real winery wastewaters. the previous stage based on heterogeneous Photo-Fenton process produces a partial degradation of winery wastewaters and achieves a yield of degradation of organic matter (measured as TOC) close to 50%. The activated sludge process in simple stage doesn't present any operation problems (bulking phenomenon) and achieves a yield of degradation of organic matter of 90%. (Author) 16 refs.

  7. Biotransformation of Domestic Wastewater Treatment Plant Sludge by Two-Stage Integrated Processes -Lsb & Ssb

    Directory of Open Access Journals (Sweden)

    Md. Zahangir Alam, A. H. Molla and A. Fakhru’l-Razi


    Full Text Available The study of biotransformation of domestic wastewater treatment plant (DWTP sludge was conducted in laboratory-scale by two-stage integrated process i.e. liquid state bioconversion (LSB and solid state bioconversion (SSB processes. The liquid wastewater sludge [4% w/w of total suspended solids (TSS] was treated by mixed filamentous fungi Penicillium corylophilum and Aspergillus niger, isolated, screened and mixed cultured in terms of their higher biodegradation potential to wastewater sludge. The biosolids was increased to about 10% w/w. Conversely, the soluble [i.e. Total dissolve solid (TDS] and insoluble substances (TSS in treated supernatant were decreased effectively in the LSB process. In the developed LSB process, 93.8 g kg-1of biosolids were enriched with fungal biomass protein and nutrients (NPK, and 98.8% of TSS, 98.2% of TDS, 97.3% of turbidity, 80.2% of soluble protein, 98.8% of reducing sugar and 92.7% of chemical oxygen demand (COD in treated sludge supernatant were removed after 8 days of treatment. Specific resistance to filtration (1.39x1012 m/kg was decreased tremendously by the microbial treatment of DWTP sludge after 6 days of fermentation. The treated biosolids in DWTP sludge was considered as pretreated resource materials for composting and converted into compost by SSB process. The SSB process was evaluated for composting by monitoring the microbial growth and its subsequent roles in biodegradation in composting bin (CB. The process was conducted using two mixed fungal cultures, Trichoderma harzianum with Phanerochaete chrysosporium 2094 and (T/P and T. harzianum and Mucor hiemalis (T/M; and two bulking materials, sawdust (SD and rice straw (RS. The most encouraging results of microbial growth and subsequent solid state bioconversion were exhibited in the RS than the SD. Significant decrease of the C/N ratio and germination index (GI were attained as well as the higher value of glucosamine was exhibited in compost; which

  8. Enhanced integrated nonthermal treatment system study

    Energy Technology Data Exchange (ETDEWEB)

    Biagi, C.; Schwinkendorf, B.; Teheranian, B.


    The purpose of the Enhanced Nonthermal Treatment Systems (ENTS) study is to evaluate alternative configurations of one of the five systems evaluated in the Integrated Nonthermal Treatment Systems (INTS) study. Five alternative configurations are evaluated. Each is designed to enhance the final waste form performance by replacing grout with improved stabilization technologies, or to improve system performance by improving the destruction efficiency for organic contaminants. AU enhanced systems are alternative configurations of System NT-5, which has the following characteristics: Nonthermal System NT-5: (1) catalytic wet oxidation (CWO) to treat organic material including organic liquids, sludges, and soft (or combustible) debris, (2) thermal desorption of inorganic sludge and process residue, (3) washing of soil and inorganic debris with treatment by CWO of removed organic material, (4) metal decontamination by abrasive blasting, (5) stabilization of treated sludge, soil, debris, and untreated debris with entrained contamination in grout, and (6) stabilization of inorganic sludge, salts and secondary waste in polymer. System NT-5 was chosen because it was designed to treat combustible debris thereby minimizing the final waste form volume, and because it uses grout for primary stabilization. The enhanced nonthermal systems were studied to determine the cost and performance impact of replacing grout (a commonly used stabilization agent in the DOE complex) with improved waste stabilization methods such as vitrification and polymer.

  9. Fish canning wastewater treatment by activated sludge: Application of factorial design optimization

    Directory of Open Access Journals (Sweden)

    Raquel O. Cristóvão


    Full Text Available The optimization of hydraulic retention time (HRT and initial organic matter concentration for dissolved organic carbon (DOC abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM. The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC removal were fitted into a quadratic polynomial model using factorial design and RSM. The optimum process conditions were determined by analyzing the response surface of a three-dimensional plot and by solving the regression model equation. The obtained results showed a HRT of 6.4 h and an initial DOC of 406.2 mg/L as the best treatment conditions. Under these conditions, the maximum predicted DOC removal was 88.0%, confirming the feasibility and the reliability of fish canning wastewater treatment by activated sludge for organic content removal.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  12. Separate treatment of turbid water from sludge treatment; Separate Behandlung von Truebwaessern aus der Schlammbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B.; Arnold, E.; Wilderer, P.A. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl und Pruefamt fuer Wasserguete- und Abfallwirtschaft


    In semi-technical investigations, discontinuous activated sludge processes and biofilm processes for the nitrification of sludge water were compared. Both processes were found to be equally suited for this application. (orig.) [German] In halbtechnischen Untersuchungen wurden diskontinuierlich betriebene Belebtschlamm- und Biofilmverfahren zur Nitrifikation von Schlammwaessern gegenuebergestellt. Es zeigte sich, dass beide Verfahren gleichermassen fuer diese Anwendung geeignet sind. (orig.)

  13. Fate of antibiotic resistance genes in mesophilic and thermophilic anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge. (United States)

    Jang, Hyun Min; Shin, Jingyeong; Choi, Sangki; Shin, Seung Gu; Park, Ki Young; Cho, Jinwoo; Kim, Young Mo


    Anaerobic digestion (AD) of chemically enhanced primary treatment (CEPT) sludge and non-CEPT (conventional sedimentation) sludge were comparatively operated under mesophilic and thermophilic conditions. The highest methane yield (692.46±0.46mL CH 4 /g VS removed in CEPT sludge) was observed in mesophilic AD of CEPT sludge. Meanwhile, thermophilic conditions were more favorable for the removal of total antibiotic resistance genes (ARGs). In this study, no measurable difference in the fates and removal of ARGs and class 1 integrin-integrase gene (intI1) was observed between treated non-CEPT and CEPT sludge. However, redundancy analysis indicated that shifts in bacterial community were primarily accountable for the variations in ARGs and intI1. Network analysis further revealed potential host bacteria for ARGs and intI1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Evaluation of sludge properties in a pilot-scale UASB reactor for sewage treatment in a temperate region. (United States)

    Syutsubo, K; Yoochatchaval, W; Tsushima, I; Araki, N; Kubota, K; Onodera, T; Takahashi, M; Yamaguchi, T; Yoneyama, Y


    In this study, continuous operation of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor for sewage treatment was conducted for 630 days to investigate the physical and microbial characteristics of the retained sludge. The UASB reactor with a working volume of 20.2 m(3) was operated at ambient temperature (16-29 °C) and seeded with digested sludge. After 180 days of operation, when the sewage temperature had dropped to 20 °C or lower, the removal efficiency of both total suspended solids (TSS) and total biochemical oxygen demand (BOD) deteriorated due to washout of retained sludge. At low temperature, the cellulose concentration of the UASB sludge increased owing to the rate limitation of the hydrolytic reaction of suspended solids in the sewage. However, after an improvement in sludge retention (settleability and concentration) in the UASB reactor, the process performance stabilized and gave sufficient results (68% of TSS removal, 75% of total BOD removal) at an hydraulic retention time (HRT) of 9.7 h. The methanogenic activity of the retained sludge significantly increased after day 246 due to the accumulation of Methanosaeta and Methanobacterium following the improvement in sludge retention in the UASB reactor. Acid-forming bacteria from phylum Bacteroidetes were detected at high frequency; thus, these bacteria may have an important role in suspended solids degradation.

  15. Microalgae-activated sludge treatment of molasses wastewater in sequencing batch photo-bioreactor. (United States)

    Tsioptsias, Costas; Lionta, Gesthimani; Samaras, Petros


    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.

  16. Recovery and reuse of sludge from active and passive treatment of mine drainage-impacted waters: a review. (United States)

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


    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.

  17. Treatment of sludge containing nitro-aromatic compounds in reed-bed mesocosms - Water, BOD, carbon and nutrient removal. (United States)

    Gustavsson, L; Engwall, M


    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Cost minimization in a full-scale conventional wastewater treatment plant: associated costs of biological energy consumption versus sludge production. (United States)

    Sid, S; Volant, A; Lesage, G; Heran, M


    Energy consumption and sludge production minimization represent rising challenges for wastewater treatment plants (WWTPs). The goal of this study is to investigate how energy is consumed throughout the whole plant and how operating conditions affect this energy demand. A WWTP based on the activated sludge process was selected as a case study. Simulations were performed using a pre-compiled model implemented in GPS-X simulation software. Model validation was carried out by comparing experimental and modeling data of the dynamic behavior of the mixed liquor suspended solids (MLSS) concentration and nitrogen compounds concentration, energy consumption for aeration, mixing and sludge treatment and annual sludge production over a three year exercise. In this plant, the energy required for bioreactor aeration was calculated at approximately 44% of the total energy demand. A cost optimization strategy was applied by varying the MLSS concentrations (from 1 to 8 gTSS/L) while recording energy consumption, sludge production and effluent quality. An increase of MLSS led to an increase of the oxygen requirement for biomass aeration, but it also reduced total sludge production. Results permit identification of a key MLSS concentration allowing identification of the best compromise between levels of treatment required, biological energy demand and sludge production while minimizing the overall costs.

  19. Use of dry sludge from waste water treatment plants as an additive in prefabricated concrete brick

    Directory of Open Access Journals (Sweden)

    Yagüe, A.


    Full Text Available Dry sludge from the Sabadell Water Treatment Plant was used to prepare prefabricated concrete bricks. After characterising the sludge and the manufacturing process used to make the bricks, we define the conditions of addition of the sludges in the manufacture. Reference samples not containing sludge and samples containing 2 % of dry sludge by cement weight were prepared. The variation in density, porosity, absorption coefficient and compressive strength of the bricks with the presence of sludge was determined over time. Leaching of the bricks was determined according to the NEN 7345 standard. In most cases the addition of sludge produces a decrease in porosity and absorption coefficients and an increase in compressive strength, so one could expect these bricks to have greater durability. As regards leaching pollutants in the bricks, they are below the limit of the Dutch NEN standard for construction materials and thus can be classified as inert material.

    El estudio ha consistido en la utilización de lodo seco de origen biológico de la depuradora de aguas residuales de Sabadell (Riu Sec, como adición en la preparación de adoquines de hormigón prefabricado. Después de caracterizar los lodos y el proceso de fabricación de los adoquines que utilizaremos, definimos las condiciones de adición de los lodos en esta fabricación. Se prepararon muestras de referencia, sin adición, y muestras con el 2 % de lodo seco sobrepeso de cemento. Se determinaron cómo variaban en el tiempo, con la presencia de lodos: la densidad, la porosidad y el coeficiente de absorción, y la resistencia mecánica a compresión de los adoquines. También se determinó la lixiviación que estas piezas presentaban de acuerdo a la norma NEN 7345. La adición de lodos produce, en la mayoría de los casos, una disminución de las porosidades y de los coeficientes de absorción y un aumento en las resistencias mecánicas, por lo que cabe esperar una mayor

  20. Fish canning wastewater treatment by activated sludge: Application of factorial design optimization


    Raquel O. Cristóvão; Gonçalves, Cristiana; Botelho, Cidália M.; Ramiro J.E. Martins; Loureiro, J. M.; Boaventura, Rui A.R.


    The optimization of hydraulic retention time (HRT) and initial organic matter concentration for dissolved organic carbon (DOC) abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM). The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC removal were fitted into a quadratic polynomial model using factorial design a...

  1. The influence of glycerin on nitrogen removal in wastewater treatment with activated sludge (United States)

    Smyk, Joanna; Ignatowicz, Katarzyna


    The paper presents the efficiency of nitrogen removal from wastewater using glycerin as an external carbon source. The study was conducted during the municipal wastewater treatment process in two independent activated sludge chambers of SBR type. One of the chambers contained glycerol as the source of easily available organic compounds. The study showed that the use of glycerol as the external carbon source resulted in a higher efficiency of nitrogen removal in compare with the reactor without external carbon source.

  2. Characterization and biodegradability of sludge from a high rate A-stage contact tank and B-stage membrane bioreactor of a pilot-scale AB system treating municipal wastewaters. (United States)

    Trzcinski, Antoine Prandota; Ganda, Lily; Kunacheva, Chinagarn; Zhang, Dong Qing; Lin, Li Leonard; Tao, Guihe; Lee, Yingjie; Ng, Wun Jern


    In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been tailored towards energy self-sufficiency. The AB process is a promising technology for achieving maximal energy recovery from wastewaters with minimum energy expenditure and therefore inherently reducing excess sludge production. Characterization of this novel sludge and its comparison with the more conventional B-stage sludge are necessary for a deeper understanding of AB treatment process design. This paper presents a case study of a pilot-scale AB system treating municipal wastewaters as well as a bio- (biochemical methane potential and adenosine tri-phosphate analysis) and physico-chemical properties (chemical oxygen demand, sludge volume index, dewaterability, calorific value, zeta potential and particle size distribution) comparison of the organic-rich A-stage against the B-stage activated sludge. Compared to the B-sludge, the A-sludge yielded 1.4 to 4.9 times more methane throughout the 62-week operation.

  3. Toxicity of ionic liquid cations and anions towards activated sewage sludge organisms from different sources -- consequences for biodegradation testing and wastewater treatment plant operation. (United States)

    Markiewicz, Marta; Piszora, Magdalena; Caicedo, Nelson; Jungnickel, Christian; Stolte, Stefan


    Ionic liquids (ILs) have attracted great interest in academia and industry during the last decade. So far, several ILs have been used in technological processes, from small scale to industrial applications, which makes it more and more likely that they will be released into the environment. Researchers have been actively studying the environmental and toxicological behaviour of ILs, but their influence on the activated sludge communities of wastewater treatment plants have yet to be investigated. This study aims to fill this knowledge gap by systematically investigating the influence of ILs on activated sewage sludge communities. We tested the inhibition of activated sludge respiration (according to OECD guideline 209) by a selection of 19 different compounds covering the chemical space of ILs as comprehensively as possible. To elicit the differences in sensitivities/tolerances towards ILs we investigated activated sludge from different domestic and industrial sources. Generally speaking, the structure activity relationships of IL toxicity towards activated sludge are in good agreement with those found for other organisms and test systems. The inhibitory potential of tested ILs substituted with short alkyl chains (≤ 4) and polar anions was low. On the other hand, the toxic effects of highly hydrophobic ionic cations and anions were greater - IC50 values were low, some < 50 μM (<10 mg L(-1)). We were able to demonstrate that the EC50 values from Vibrio fischeri can be used for a reliable assessment of the sludge inhibition potential of tested ILs. All the results are discussed in the context of their consequences for biodegradation processes and the performance of wastewater treatment plants. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhu, Yunhua [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Susanne B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elliott, Douglas C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schmidt, Andrew J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hallen, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billing, Justin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Todd R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fox, Samuel P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maupin, Gary D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    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

  5. Modelling inorganic material in activated sludge systems | Ekama ...

    African Journals Online (AJOL)

    The predicted reactor VSS/TSS ratio reflects the observed relative sensitivity to sludge age, which is low, and to BEPR, which is high. For effective use of the model for design, two significant issues require attention: measurement of the influent ISS concentration, which is not commonly done in wastewater characterisation ...

  6. Thermal mineralization. Pyreg - a method for decentralized sewage sludge treatment; Thermisch mineralisiert. Pyreg - ein Verfahren zur dezentralen Klaerschlammaufbereitung

    Energy Technology Data Exchange (ETDEWEB)

    Sehn, Winfried [Fachhochschule Bingen (Germany). Energie- und Motorentechnik; Gerber, Helmut [Fachhochschule Bingen (Germany); Institut fuer Innovation, Transfer und Beratung (ITB) gGmbH, Bingen (Germany); Pyreg GmbH, Gemuenden (Germany); Siekmann, Klaus [Ingenieurgesellschaft Dr.-Ing. K. Siekmann und Partner mbH, Thuer, Westerburg Simmern, Bad Ems (Germany); Scherer, Jochen [Metallbau Scherer GmbH, Gemuenden (Germany); Pyreg GmbH, Gemuenden (Germany)


    Sewage sludge produced during wastewater treatment has to be considered as waste that usually causes high technical and energetic effort for thermal utilization and disposal. Even the agricultural use cannot be continued in the traditional way when the coming sewage sludge regulation will tighten measures for harmful substances and pathogenic germs. The thermal pyrolysis of regenerative substances in the Pyreg-plant that is described in this paper enables the mineralization of sewage sludge using the biomass energy and generates the requirements for cheap disposal and for the recycling of the useful components like phosphor. (orig.)

  7. Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Changxiu [School of Environment, Tsinghua University, Beijing 100084 (China); Jiang, Jianguo, E-mail: [School of Environment, Tsinghua University, Beijing 100084 (China); Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China (China); Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing (China); Li, De' an [School of Environment, Tsinghua University, Beijing 100084 (China)


    We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO{sub 4}{sup 3−} concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton.

  8. An evaluation of tannery industry wastewater treatment sludge gasification by artificial neural network modeling. (United States)

    Ongen, Atakan; Ozcan, H Kurtulus; Arayıcı, Semiha


    This paper reports on the calorific value of synthetic gas (syngas) produced by gasification of dewatered sludge derived from treatment of tannery wastewater. Proximate and ultimate analyses of samples were performed. Thermochemical conversion alters the chemical structure of the waste. Dried air was used as a gasification agent at varying flow rates, which allowed the feedstock to be quickly converted into gas by means of different heterogeneous reactions. A lab-scale updraft fixed-bed steel reactor was used for thermochemical conversion of sludge samples. Artificial neural network (ANN) modeling techniques were used to observe variations in the syngas related to operational conditions. Modeled outputs showed that temporal changes of model predictions were in close accordance with real values. Correlation coefficients (r) showed that the ANN used in this study gave results with high sensitivity. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Diversity of microbial carbohydrate-active enzymes in Danish anaerobic digesters fed with wastewater treatment sludge

    DEFF Research Database (Denmark)

    Wilkens, Casper; Busk, Peter Kamp; Pilgaard, Bo


    , making the ADs a unique niche to look for CAZymes that can potentiate the enzyme blends currently used in industry. Enzymatic assays showed that functional CAZymes were secreted into the AD environments in four full-scale mesophilic Danish ADs fed with primary and surplus sludge from municipal wastewater...... treatment plants. Metagenomes from the ADs were mined for CAZymes with Homology to Peptide Patterns (HotPep). 19,335 CAZymes were identified of which 30% showed 50% or lower identity to known proteins demonstrating that ADs make up a promising pool for discovery of novel CAZymes. A function was assigned...... metagenomes. The cellulytic enzymes were limited almost to endoglucanases and β-glucosidases, which reflect the large amount of partly degraded cellulose in the sludge. No dockerin domains were identified suggesting that the cellulytic enzymes in the ADs studied operate independently. Of xylanolytic CAZymes...

  10. Enhancement of sludge granulation in anaerobic treatment of concentrated latex wastewater

    Directory of Open Access Journals (Sweden)

    Nugul Intrasungkha


    Full Text Available Recently, the upflow anaerobic sludge blanket (UASB reactor has become attractive for wastewater treatment with low energy requirement and biogas production. However, the start-up of an UASB reactor depends on the formation of granules. Therefore, this research aims to study the effect of AlCl3, CaCl2 and temperature on the granule formation process using real concentrated latex wastewater. The result shows that the optimum chemicals concentration of AlCl3 at 300 mg/l enhanced the biomass accumulation and sludge formation process. Approximately 50% of large granular size (0.5 mm 0.8 mm within 35 days, whereas the large granular sizes in reactorwithout AlCl3 supplement (R2 became visible within 63 days. Moreover, this experiment found that R1, R2 and R3 could reach steady state within 40, 55 and 45 days, respectively.

  11. An evaluation of tannery industry wastewater treatment sludge gasification by artificial neural network modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ongen, Atakan, E-mail:; Kurtulus Ozcan, H.; Arayıcı, Semiha


    Highlights: • We model calorific value of syn-gas from tannery industry treatment sludge. • We monitor variation of gas composition in produced gas. • Heating value of produced gas is around 1500 kcal/m{sup 3}. • Model predictions are in close accordance with real values. -- Abstract: This paper reports on the calorific value of synthetic gas (syngas) produced by gasification of dewatered sludge derived from treatment of tannery wastewater. Proximate and ultimate analyses of samples were performed. Thermochemical conversion alters the chemical structure of the waste. Dried air was used as a gasification agent at varying flow rates, which allowed the feedstock to be quickly converted into gas by means of different heterogeneous reactions. A lab-scale updraft fixed-bed steel reactor was used for thermochemical conversion of sludge samples. Artificial neural network (ANN) modeling techniques were used to observe variations in the syngas related to operational conditions. Modeled outputs showed that temporal changes of model predictions were in close accordance with real values. Correlation coefficients (r) showed that the ANN used in this study gave results with high sensitivity.


    Directory of Open Access Journals (Sweden)

    Janusz Dąbrowski


    Full Text Available The paper presents results of laboratory studies on the possibility of co-incineration of sewage sludge with waste rubber, as the possibility of thermal treatment of both: sludge and examined waste. Municipal sewage sludge, taken from the Wastewater Treatment Plant in Tychowo and waste bicycle tires ware used in the examinations. In addition, results were compared with the results of coincineration of analysed sewage sludge mixed with hard coal as classic fuel. The initial stage of the study was a technical analysis of materials used in the examinations. Results of the analysis of exhaust gas fluxes, resulting from the co-incineration of examined waste and sewage sludge were presented and evaluated in the next part of paper. Following parameters were determined: cSO2 – concentration of sulfur oxide (IV, cNOx –concentration of nitrogen oxides. Variable independent parameters determined during studies of mixtures incineration were: mass fraction of sludge in the fuel mixture, temperature in the combustion zone of the furnace and the excess air coefficient. Analysis of energetic properties and emissions of pollutants, under tested conditions of incineration of those mixtures, allowed determining the maximum share of sewage sludge in the fuel mixture and impact of variability of independent parameters of the incineration process on the quality of this process. Final analysis of energetic properties of mixtures and results of examinations on incineration conditions of those mixtures proved, that maximum mass fraction of sewage sludge should not exceed 10%. Increase of incineration temperature significantly decreases quality of thermal processing of examined sewage sludge, increasing emissions of sulfur oxide (IV and, to a greater extent, of nitrogen oxides NOx. Increase of oxygen amount, along with air fed into incineration chamber caused, causes increase of nitrogen oxides emission and slight changes of sulfur dioxide concentration.

  13. Effect of wastewater treatment processes on the pyrolysis properties of the pyrolysis tars from sewage sludges (United States)

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


    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.

  14. Thermal pre-treatment of primary and secondary sludge at 70ºC prior to anaerobic digestion

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, H.N.; Lu, Jingquan


    In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic digestion, mainly because of the lower energy requirements and higher stability of the process. However, the thermophilic anaerobic digestion process is usually characterised by accelerated....... The present study investigates the effect of the pre-treatment at 70 degrees C on thermophilic (55 degrees C) anaerobic digestion of primary and secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondary sludge at 70 degrees C enhanced the removal of organic matter...... and the methane production during the subsequent anaerobic digestion step at 55 degrees C. It also greatly contributed to the destruction of pathogens present in primary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic step suggesting that the same efficiencies in organic...

  15. Anaerobic sewage treatment in a one-stage UASB reactor and a combined UASB Digester system

    NARCIS (Netherlands)

    Mahmoud, N.A.; Zeeman, G.; Gijzen, H.J.; Lettinga, G.


    The treatment of sewage at 15°C was investigated in a one-stage upflow anaerobic sludge blanket (UASB) reactor and a UASB-Digester system. The latter consists of a UASB reactor complemented with a digester for mutual sewage treatment and sludge stabilisation. The UASB reactor was operated at a

  16. Mathematical model for sizing combined nitrification and pre-denitrification activated sludge systems

    NARCIS (Netherlands)

    Esposito, G.; Fabbricino, M.; Lens, P.N.L.; Pirozzi, F.


    Two mathematical steady-state models for sizing single activated sludge systems aimed at nitrogen and organics removal from wastewater are proposed. The attention is focused on the combined nitrification system and the pre-denitrification system, considering three (soluble and particulate

  17. Ozonation and thermal pre-treatment of municipal sewage sludge – Implications for toxicity and methane potential

    DEFF Research Database (Denmark)

    Davidsson, A.; Eriksson, Eva; Fick, J.

    The aim of this study was to determine the effects on the methane potential and the overall sludge quality from two different sludge pre-treatment technologies (ozonation high/low dosage and thermal treatment 55/70 °C). In general both treatments gave an increased methane potential. The thermal...... treatment resulted in higher chemical oxygen demand (COD)-solubilisation, while the highest volatile fatty acids (VFA) increase was obtained with ozonation. The sludges had inhibiting effects in a barley seed germination assay and a yeast oestrogen screen both before and after pre......-treatment, but the inhibition was reduced by ozone treatment and digestion. No statistical significant reduction in concentrations of the included pharmaceuticals could be seen....

  18. Fate of Triclosan in activated sludge treatment - bridging the missing gap

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina

    %. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we......Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore...

  19. Energy recovery from wastewater treatment plants through sludge anaerobic digestion: effect of low-organic-content sludge. (United States)

    Zhang, Yuyao; Li, Huan


    During anaerobic digestion, low-organic-content sludge sometimes is used as feedstock, resulting in deteriorated digestion performance. The operational experience of conventional anaerobic digestion cannot be applied to this situation. To investigate the feature of low-organic-content sludge digestion and explain its intrinsic mechanism, batch experiments were conducted using designed feedstock having volatile solids (VS) contents that were 30-64% of total solids (TS). The results showed that the accumulative biogas yield declined proportionally from 173.7 to 64.8 ml/g VS added and organic removal rate decreased from 34.8 to 11.8% with decreasing VS/TS in the substrate. The oligotrophic environment resulting from low-organic-content substrates led to decreased microbial activity and a switch from butyric fermentation to propionic fermentation. A first-order model described the biogas production from the batch experiments very well, and the degradation coefficient decreased from 0.159 to 0.069 day-1, exhibiting a positive relation with organic content in substrate. The results observed here corroborated with data from published literature on anaerobic digestion of low-organic-content sludge and showed that it may not be feasible to recover energy from sludge with an organic content lower than 50% through mono digestion.

  20. Dielectric and electric properties as a tool to investigate the coagulation mechanism during sludge treatment. (United States)

    Mortadi, A; Chahid, El G; Nasrellah, H; Cherkaoui, O; El Moznine, R


    The analysis of the complex permittivity, electrical complex modulus and the hopping conductivity have been employed in order to investigate the impacts of calcium oxide during sludge treatment in textile such as coagulation process. In this context, impedance measurement was performed on five samples, including raw sludge and four compositions containing different amounts of calcium oxide: 2%, 3%, 4% and 5% (w/w). The dielectric spectra of each composition were described by the summation of a power law and a Cole-Cole relaxation model. The relaxation time and the magnitude of the dielectric relaxation obtained from the analysis of dielectric properties showed an increase up to 3% of these parameters with the addition of calcium oxide. Above this critical value, both parameters showed a very small change, suggesting that the aggregation became more stable. In addition, the evolution of the hopping conductivity reached a minimum value at this critical amount (3%). This evolution was well described by a double power law, which allowed us to estimate the optimal amount of the calcium oxide to achieve coagulation process. The analysis of the dielectric properties was found useful in monitoring aggregation processes that occur during the coagulation mechanism in textile sludge.

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

    Directory of Open Access Journals (Sweden)

    Zubayeda Zahan


    Full Text Available 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.

  2. Primary Treatment and Sludge Digestion Workshop. Second Edition (Revised). (United States)

    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,…

  3. Effects of Physico-Chemical Post-Treatments on the Semi-Continuous Anaerobic Digestion of Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Xinbo Tian


    Full Text Available Sludge production in wastewater treatment plants is increasing worldwide due to the increasing population. This work investigated the effects of ultrasonic (ULS, ultrasonic-ozone (ULS-Ozone and ultrasonic + alkaline (ULS+ALK post-treatments on the anaerobic digestion of sewage sludge in semi-continuous anaerobic reactors. Three conditions were tested with different hydraulic retention times (HRT, 10 or 20 days and sludge recycle ratios (R = QR/Qin (%: 50 or 100%. Biogas yield increased by 17.8% when ULS+ALK post-treatment was applied to the effluent of a reactor operating at 20 days HRT and at a 100% recycle ratio. Operation at 10 days HRT also improved the biogas yield (277 mL CH4/g VSadded (VS: volatile solids versus 249 mL CH4/g VSadded in the control. The tested post-treatment methods showed 4–7% decrease in effluent VS. The post-treatment resulted in a decrease in the cellular ATP (Adenosine tri-phosphate concentration indicating stress imposed on microorganisms in the reactor. Nevertheless, this did not prevent higher biogas production. Based on the results, the post-treatment of digested sludge or treating the sludge between two digesters is an interesting alternative to pre-treatments.

  4. Stabilization of tannery sludge by co-treatment with aluminum anodizing sludge and phytotoxicity of end-products. (United States)

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


    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Combined treatment of mezcal vinasses by ozonation and activated sludge. (United States)


    In Mexico, mezcal production generates huge amounts of vinasses (MV) that cause negative environmental impacts. Thus, MV treatment is necessary before discharge to water bodies. Although there is no information for mezcal vinasses, similar effluents have been treated by biological processes (i.e. anaerobic and aerobic) usually complemented by oxidative chemical pretreatments (ozonation) and physico-chemical methods. In this work MV were first ozonated and followed by batch aerobic biological degradation. In the ozonation stage, organic matter removals were 4.5-11 % as COD, whereas the removal of aromatic compounds and phenols were 16-32 % and 48-83 % respectively. In the aerobic post-treatment, COD depletions up to 85 % were achieved; removals in ozone pre-treated vinasses were higher (80 to 85 %) than that of raw vinasse (69 %). It seems that ozonation preferentially attacked the recalcitrant fraction of organic matter present in the vinasses and increased its aerobic biodegradability.

  6. Advances in distributed parameter approach to the dynamics and control of activated sludge processes for wastewater treatment. (United States)

    Lee, T T; Wang, F Y; Newell, R B


    This paper presents a review of modelling and control of biological nutrient removal (BNR)-activated sludge processes for wastewater treatment using distributed parameter models described by partial differential equations (PDE). Numerical methods for solution to the BNR-activated sludge process dynamics are reviewed and these include method of lines, global orthogonal collocation and orthogonal collocation on finite elements. Fundamental techniques and conceptual advances of the distributed parameter approach to the dynamics and control of activated sludge processes are briefly described. A critical analysis on the advantages of the distributed parameter approach over the conventional modelling strategy in this paper shows that the activated sludge process is more adequately described by the former and the method is recommended for application to the wastewater industry.

  7. Treatment of azo dye Acid Orange 52 using ozonation and completed-mixed activated sludge process (United States)

    Abidin, C. Z. A.; Fahmi; Ong, S. A.; Ahmad, R.; Sabri, S. N.


    In this study, the characteristic of colour and COD removal of azo dye Acid Orange 52 (AO52) by ozonation, in combination with complete-mixed activated sludge process (CMAS) was evaluated. The experimentation was arranged in two phases: during the first one, only ozonation was performed, while, during the second phase, it was integrated with CMAS. The performance of colour and COD concentration of AO52 with and without CMAS treatment, is compared and evaluated. From the results, it is obvious that high decolourization from the start of CMAS was contributed from the pre-treatments. The colour removal was due to the fact that ozonation able to cleave the azo bonds that represent colour. Thus, CMAS without pre-treatment are unable to decolourize the dyes sufficiently. 59.6% COD was removed from the first-stage, while merely 9.8% COD fraction removed from the subsequence second-stage CMAS. It is suggested that the rapid COD removal without ozonation are due to activated sludge adsorption processes. The decreased of mixed liquor suspended solids (MLSS) affected the CMAS performances, as the biomass decreased due to lack of nutrient for activated sludge microorganisms to multiply. Results from pre-ozonation alone contributed more than 50% of total COD removal, which indicated that at higher ozone dosage, tend to mineralize azo dye. Thus, ozonation not oxidized the dye though complete mineralization that produce carbon dioxide and water. However, it is a potential process for enhancing colour removal and biodegradability of dye-containing wastewater, once the appropriate ozonation time is determined. Therefore, the role of ozonation seems to break down the dye molecules and created ozonation by-product that is easily biodegraded in the subsequent biological treatment.

  8. Packaging design criteria for the K east basin sludge transportation system

    Energy Technology Data Exchange (ETDEWEB)

    Tomaszewski, T.A., Westinghouse Hanford


    This packaging design criteria (PDC) establishes the onsite transportation safety criteria for a reusable packaging and transport system to transport K East Basin sludge and water.This PDC provides the basis for the development of a safety analysis report for packaging; establishes the packaging contents and safety class of the package; and provides design criteria for the package, packaging, and transport systems.

  9. Modelling as a tool when interpreting biodegradation of micro pollutants in activated sludge systems

    DEFF Research Database (Denmark)

    Press-Kristensen, Kåre; Lindblom, Erik Ulfson; Henze, Mogens


    The aims of the present work were to improve the biodegradation of the endocrine disrupting micro pollutant, bisphenol A (BPA), used as model compound in an activated sludge system and to underline the importance of modelling the system. Previous results have shown that BPA mainly is degraded under...

  10. End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Lars-Flemming; Nielsen, J.L.


    A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation ofsingle-sludge denitrification, a process eliminating nitrate from the aqueous environment while reduc-ing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each...

  11. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye


    by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change......-rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

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

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


    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. JPL Activated Carbon Treatment System (ACTS) for sewage (United States)


    An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

  14. Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions

    NARCIS (Netherlands)

    Seghezzo, L.; Cuevas, C.M.; Trupiano, A.P.; Guerra, R.G.; Gonzalez, S.M.; Zeeman, G.; Lettinga, G.


    The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical


    Directory of Open Access Journals (Sweden)

    Robin Mujačić


    Full Text Available The multifuncional role and importance of organic matter in soil is widely known. It is also known that the organic matter in soil is subjected to microbiological-biochemical processes of transformation, which includes synthesis of humus as well as it’s decomposition -mineralization. Mineralization means transformation-decomposition of organic matter by microbiological processes to mineral products; plant nutrients and water + CO2 as starting and ending component of photosyntesis. Nutrients are partly plant available with fertilizing effect, partly lost from the soil - leaching in ground water, causing it’s eutrophication, but CO2 in atmosphere participates in greenhouse effect. Practically, mineralization means decreasing of organic matter content in soil and soil degradation [1,4]. In natural ecosystems (phytocenoses natural forests and meadows, it is almost a balanced between inflow and consumption of organic matter, while the cultural and anthropogenic soils agrobiocenosis in general, this relationship is disturbed that there is a disproportion between the inflow and loss [1,4]. Therefore, various materials that contains organic material (waste, various flotation, sludge, etc. are often used with more or less success. One of such materials, as well as the potential fertilizer, is carboniferous lake sludge like waste of coal mining sedimented at the bottom of the lake in huge quantities, which is the subject of our reasearch. The research were conducted to determine its fertilizing efects and value for repairing of physical and chemical properties of soil. The research refered to: -- Laboratory analysis of physical and chemical characteristics of the carboniferous sludge samples, -- Analysis of soil of the experimental field -- Research on heavy metals concentration in soil of the experimental farm and in carboniferous sludge, and Research of fertilizing effects of sludge, comparative mineral fertilizer and farmyard manure treatment by

  16. Determination of alkylphenols and alkylphenol ethoxylates in sewage sludge: effect of sample pre-treatment. (United States)

    Fernández-Sanjuan, María; Rigol, Anna; Sahuquillo, Angels; Rodríguez-Cruz, Sonia; Lacorte, Silvia


    A complete characterization of sewage sludge collected from five biological waste water treatment plants was done to determine physico-chemical parameters, heavy metals and alkylphenols, making special emphasis on sampling, homogenization, and sample pre-treatment. Ultrasonic extraction followed by gas chromatrography coupled with mass spectrometry was used to evaluate the effect of sample pre-treatment (untreated sample, freeze-drying, drying at 40 degrees C or drying at 100 degrees C) on the concentration of octylphenol (OP), nonylphenol (NP) and nonylphenol ethoxylates (NP1EO, NP2EO). Untreated samples and samples dried at 100 degrees C gave concentration levels up to 62% and 89% lower, respectively, than freeze-dried samples. In 50% of cases, freeze-dried samples led to significantly higher concentrations than those obtained by drying at 40 degrees C. Thus, freeze-drying is the recommended sample pre-treatment to prevent possible losses of OP, NP, and NP1EO. Using this methodology, concentrations detected were from 3.2 to 199 mg kg(-1) being NP followed by NP1EO found in highest concentration. The total concentration of NP and NP1EO exceeded the limit of 50 mg kg(-1) proposed by the draft European directive on sewage sludge in three out of five samples studied. Contrarily, heavy metals were below the legislated values.

  17. Determination of alkylphenols and alkylphenol ethoxylates in sewage sludge: effect of sample pre-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Sanjuan, Maria; Rigol, Anna; Sahuquillo, Angels [University of Barcelona, Department of Analytical Chemistry, Barcelona (Spain); Rodriguez-Cruz, Sonia [University of Barcelona, Department of Analytical Chemistry, Barcelona (Spain); IRNASA-CSIC, Department of Environmental Chemistry and Geochemistry, Salamanca (Spain); Lacorte, Silvia [IDAEA-CSIC, Department of Environmental Chemistry, Barcelona (Spain)


    A complete characterization of sewage sludge collected from five biological waste water treatment plants was done to determine physico-chemical parameters, heavy metals and alkylphenols, making special emphasis on sampling, homogenization, and sample pre-treatment. Ultrasonic extraction followed by gas chromatrography coupled with mass spectrometry was used to evaluate the effect of sample pre-treatment (untreated sample, freeze-drying, drying at 40 C or drying at 100 C) on the concentration of octylphenol (OP), nonylphenol (NP) and nonylphenol ethoxylates (NP{sub 1}EO, NP{sub 2}EO). Untreated samples and samples dried at 100 C gave concentration levels up to 62% and 89% lower, respectively, than freeze-dried samples. In 50% of cases, freeze-dried samples led to significantly higher concentrations than those obtained by drying at 40 C. Thus, freeze-drying is the recommended sample pre-treatment to prevent possible losses of OP, NP, and NP{sub 1}EO. Using this methodology, concentrations detected were from 3.2 to 199 mg kg{sup -1} being NP followed by NP{sub 1}EO found in highest concentration. The total concentration of NP and NP{sub 1}EO exceeded the limit of 50 mg kg{sup -1} proposed by the draft European directive on sewage sludge in three out of five samples studied. Contrarily, heavy metals were below the legislated values. (orig.)

  18. Efficient enzymatic degradation used as pre-stage treatment for norfloxacin removal by activated sludge. (United States)

    Zhao, Ruinan; Li, Xiaohong; Hu, Mancheng; Li, Shuni; Zhai, Quanguo; Jiang, Yucheng


    Norfloxacin is often found in wastewater treatment plants, groundwater, and even drinking water causing environmental concerns because of its potential undesirable effects on human health or aquatic ecosystems. However, conventional treatments cannot deal with norfloxacin efficiently. This work proposes an efficiently enzymatic degradation of norfloxacin by chloroperoxidase (CPO). 82.18% degradation efficiency of norfloxacin was achieved after 25 min reaction time at pH 5.0 with an enzyme concentration of 1.5 × 10(-9) mol L(-1). HPLC-MS was used to determine the intermediates or final products. The product analysis and determination of the chemical oxygen demand indicated if the enzymatic degradation by CPO was carried out before the usually existing bioremediation techniques (usually activated sludge) in sewage treatment plant, the effluent containing norfloxacin can be decontaminated more efficiently and thoroughly than that only by activated sludge treatment. The eco-toxicity tests using a green algae, Chlorella pyrenoidosa, indicated that the toxicity of degraded products of norfloxacin was lower than the parent norfloxacin molecule. CPO-catalyzed degradation of norfloxacin is a promising alternative for treating effluent containing norfloxacin.


    Energy Technology Data Exchange (ETDEWEB)



    This control decision addresses the Knock-Out Pot (KOP) Disposition KOP Processing System (KPS) conceptual design. The KPS functions to (1) retrieve KOP material from canisters, (2) remove particles less than 600 {micro}m in size and low density materials from the KOP material, (3) load the KOP material into Multi-Canister Overpack (MCO) baskets, and (4) stage the MCO baskets for subsequent loading into MCOs. Hazard and accident analyses of the KPS conceptual design have been performed to incorporate safety into the design process. The hazard analysis is documented in PRC-STP-00098, Knock-Out Pot Disposition Project Conceptual Design Hazard Analysis. The accident analysis is documented in PRC-STP-CN-N-00167, Knock-Out Pot Disposition Sub-Project Canister Over Lift Accident Analysis. Based on the results of these analyses, and analyses performed in support of MCO transportation and MCO processing and storage activities at the Cold Vacuum Drying Facility (CVDF) and Canister Storage Building (CSB), control decision meetings were held to determine the controls required to protect onsite and offsite receptors and facility workers. At the conceptual design stage, these controls are primarily defined by their safety functions. Safety significant structures, systems, and components (SSCs) that could provide the identified safety functions have been selected for the conceptual design. It is anticipated that some safety SSCs identified herein will be reclassified based on hazard and accident analyses performed in support of preliminary and detailed design.

  20. Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor. (United States)

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


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

  1. Phosphorus recovery as AlPO 4 from beneficially reused aluminium sludge arising from water treatment


    Zhao, X.H.; Zhao, Y.Q.; Kearney, P


    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 H 2SO 4, 2) decolorization of extraction leachate via H 2O 2 oxidation, and 3) AlPO 4 precipitation by pH adjustment, has been explored. The optimal cond...

  2. Start-up performance and granular sludge features of an improved external circulating anaerobic reactor for algae-laden water treatment. (United States)

    Yu, Yaqin; Lu, Xiwu


    The microbial characteristics of granular sludge during the rapid start of an enhanced external circulating anaerobic reactor were studied to improve algae-laden water treatment efficiency. Results showed that algae laden water was effectively removed after about 35 d, and the removal rates of chemical oxygen demand (COD) and algal toxin were around 85% and 92%, respectively. Simultaneously, the gas generation rate was around 380 mL/gCOD. The microbial community structure in the granular sludge of the reactor was complicated, and dominated by coccus and filamentous bacteria. Methanosphaera, Methanolinea, Thermogymnomonas, Methanoregula, Methanomethylovorans, and Methanosaeta were the major microorganisms in the granular sludge. The activities of protease and coenzyme F420 were high in the granular sludge. The intermittent stirring device and the reverse-flow system were further found to overcome the disadvantage of the floating and crusting of cyanobacteria inside the reactor. Meanwhile, the effect of mass transfer inside the reactor can be accelerated to help give the reactor a rapid start.

  3. Start-up performance and granular sludge features of an improved external circulating anaerobic reactor for algae-laden water treatment

    Directory of Open Access Journals (Sweden)

    Yaqin Yu


    Full Text Available The microbial characteristics of granular sludge during the rapid start of an enhanced external circulating anaerobic reactor were studied to improve algae-laden water treatment efficiency. Results showed that algae laden water was effectively removed after about 35 d, and the removal rates of chemical oxygen demand (COD and algal toxin were around 85% and 92%, respectively. Simultaneously, the gas generation rate was around 380 mL/gCOD. The microbial community structure in the granular sludge of the reactor was complicated, and dominated by coccus and filamentous bacteria. Methanosphaera, Methanolinea, Thermogymnomonas, Methanoregula, Methanomethylovorans, and Methanosaeta were the major microorganisms in the granular sludge. The activities of protease and coenzyme F420 were high in the granular sludge. The intermittent stirring device and the reverse-flow system were further found to overcome the disadvantage of the floating and crusting of cyanobacteria inside the reactor. Meanwhile, the effect of mass transfer inside the reactor can be accelerated to help give the reactor a rapid start.

  4. Metagenomic insight into the bioaugmentation mechanism of Phanerochaete chrysosporium in an activated sludge system treating coking wastewater. (United States)

    Hailei, Wang; Ping, Li; Ying, Wang; Lei, Liu; Jianming, Yao


    Phanerochaete chrysosporium was seeded to a sequencing batch reactor treating phenol wastewater. Compared to the contrast reactor (R1), the bioaugmented reactor (R2) exhibits better performance in sludge settling ability, as well as biomass and phenol removal, even though the added fungus is not persistently surviving in the reactor. Bioaugmentation improved bacterial population, growing up to 10,000 times higher than that of eukaryotes. Metagenomic sequencing results show the bioaugmentation finally increases bacterial and eukaryotic richness, but reduces their community diversity. In contrast to R1, bacterial distribution in R2 is more concentrated in Proteobacteria. The relative abundances of filamentous fungi, yeast and microalgae in R2 are all higher than those in R1 at different treatment phases, and two reactors are finally dominated by different protozoan and metazoan. In conclusion, P. chrysosporium improves reactor performances by influencing microbial community structure, and this phenomenon might be attributed to the ecological competition in sludge and toxicity reduction of phenol wastewater. The novelty of this study emphasizes why a species which is not persistently active in bioreactor still plays a crucial role in enhancing reactor performance. Results obtained here impact the conventional criteria for selection of bioaugmentation microbes used in activated sludge systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Organophosphate Triesters and Diester Degradation Products in Municipal Sludge from Wastewater Treatment Plants in China: Spatial Patterns and Ecological Implications. (United States)

    Fu, Lingfang; Du, Bibai; Wang, Fei; Lam, James C W; Zeng, Lixi; Zeng, Eddy Y


    Little is known about the occurrences, distributions, sources, and potential risks of organophosphate (OP) triesters and diester degradation products in municipal sludge from wastewater treatment plants (WWTPs). In this study, we conducted the first nationwide survey to simultaneously determine a suite of 11 OP triesters and six diester degradation products in sludge from WWTPs across China. All OP triesters were detected and three diesters were identified for the first time in sludge samples. Total concentrations of OP triesters and diester degradation products were in the ranges of 43.9-2160 and 17.0-1300 ng (g of dry weight) -1 , respectively, indicating relatively low pollution levels in China compared with those of several developed countries. A distinct geographical variation of higher concentrations of OP triesters and diesters in East China than in Central and West China was observed, suggesting that regional levels of organophosphate esters are associated with the magnitudes of regional economic development. Source analysis revealed nonchlorinated OP diesters are mainly derived from degradation in WWTPs, while chlorinated OP diesters were largely sourced from outside WWTPs. The estimated total emission fluxes of OP triesters and diesters via land-application sludge in China were approximately 330 and 134 kg/year, respectively. Further risk assessment based on risk quotient values in sludge-applied soils indicated low to medium risks for most OP triesters and diesters except tris(methylphenyl) phosphate. The significant accumulation of OP triesters and widespread occurrence of diester degradation products in sludge raise environmental concerns about these contaminants.

  6. Chlorella vulgaris cultivation in sludge extracts from 2,4,6-TCP wastewater treatment for toxicity removal and utilization. (United States)

    Wang, Lu; Chen, Xiurong; Wang, Hualin; Zhang, Yuying; Tang, Qingjie; Li, Jiahui


    Chlorella vulgaris was cultivated in different proportions of activated sludge extracts, which was from the treatment of the synthetic wastewater containing 2,4,6-trichlorophenol (2,4,6-TCP). The nutrients, total nitrogen (TN) and total phosphorus (TP), were removed over 45% and 90%, respectively. The maximum reduction amount of ecotoxicity and total organic carbon (TOC) occurred in the 100% sludge group on the 8th day (68%; 86.2 mg L-1). The variations of Excitation-emission matrix spectra (EEMs) and TOC indicated that extracellular organic matters (EOM) produced by algae led to TOC increase in the medium. The cell density was close to each other for groups with sludge extract proportion below 50%; sludge extracts (below 75% addition) had a stimulating effect on the accumulation of chlorophyll-a in per unit algal cell. Superoxide dismutase (SOD) variation demonstrated that C. vulgaris response positively to sludge extracts addition. Lipid content in C. vulgaris was up to its maximum value on the 8th day. Considering the performance on nutrients removal, toxicity reduction and algal growth, the optimal cultivation period for C. vulgaris before harvesting was around 8 days with sludge extracts proportion below 50%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Use of Moringa oleifera seed extracts to polish effluents from natural systems treating faecal sludge. (United States)

    Ngandjui Tchangoue, Yvan Anderson; Djumyom Wafo, Guy Valerie; Wanda, Christian; Kengne, Ebenezer Soh; Kengne, Ives Magloire; Fogue, Siméon Kouam


    The removal of pathogens in irrigation water is of great importance, especially in developing countries. Indeed, wastewater generally reused for agriculture in countries such as Cameroon is associated with health and environmental concerns. Recent studies have shown a strong disinfectant action of the natural coagulant from the seeds of Moringa oleifera. These findings have raised the question whether or not Moringa oleifera seed extracts, a natural coagulant, be used to polish effluents from natural systems treating faecal sludge. This paper deals with trials carried out to investigate the effect of these extracts in reducing faecal indicators from faecal sludge leachate initially treated by a two stage vertical flow constructed wetlands (VFCWs) planted with Echinochloa pyramidalis. The measurement of bacteriological and some physicochemical parameters, after three different settling times and concentrations, were used to determine the optimum conditions and assess treatment efficacy. Settling time of 3 h at a concentration of Moringa oleifera seed extracts between 267 mg/L and 333 mg/L permitted to reduce Escherichia coli and faecal coliforms from 4.85 to 3.92 ulog (86,74%) and from 5.75 to 4.87 ulog (86,39%) respectively with 1 ulog equal to 90%. For the same settling time and at a concentration of 333 mg/L, faecal streptococci were removed from 6.40 to 5.67 ulog (81,33%). This level of removal suggests that coagulant from seeds of Moringa oleifera cannot be used alone for disinfection of heavily loaded effluent. Further investigations are therefore still needed to fulfil the Cameroon and WHO guidelines for safe reuse in agriculture.

  8. Upflow anaerobic sludge blanket and aerated constructed wetlands for swine wastewater treatment: a pilot study. (United States)

    Masi, F; Rizzo, A; Martinuzzi, N; Wallace, S D; Van Oirschot, D; Salazzari, P; Meers, E; Bresciani, R


    Swine wastewater management is often affected by two main issues: a too high volume for optimal reuse as a fertilizer and a too high strength for an economically sustainable treatment by classical solutions. Hence, an innovative scheme has been tested to treat swine wastewater, combining a low cost anaerobic reactor, upflow anaerobic sludge blanket (UASB), with intensified constructed wetlands (aerated CWs) in a pilot scale experimental study. The swine wastewater described in this paper is produced by a swine production facility situated in North Italy. The scheme of the pilot plant consisted of: (i) canvas-based thickener; (ii) UASB; (iii) two intensified aerated vertical subsurface flow CWs in series; (iv) a horizontal flow subsurface CW. The influent wastewater quality has been defined for total suspended solids (TSS 25,025 ± 9,323 mg/l), organic carbon (chemical oxygen demand (COD) 29,350 ± 16,983 mg/l), total reduced nitrogen and ammonium (total Kjeldahl nitrogen (TKN) 1,783 ± 498 mg/l and N-NH4+ 735 ± 251 mg/l) and total phosphorus (1,285 ± 270 mg/l), with nitrates almost absent. The overall system has shown excellent performances in terms of TSS, COD, N-NH4+ and TKN removal efficiencies (99.9%, 99.6%, 99.5%, and 99.0%, respectively). Denitrification (N-NO3- effluent concentration equal to 614 ± 268 mg/l) did not meet the Italian quality standards for discharging in water bodies, mainly because the organic carbon was almost completely removed in the intensified CW beds.

  9. Releasing characteristics of phosphorus and other substances during thermal treatment of excess sludge. (United States)

    Xue, Tao; Huang, Xia


    The releasing characteristics of phosphorus, nitrogen compounds, organics, and some metal cations during thermal treatment of excess sludge were investigated. It was found that during heating not only phosphorus, but also nitrogen compounds, organics, and some metal cations could be released in abundance. The maximum orthophosphate (ortho-P) release of about 90 mg/L in concentration was observed at 50 degrees C in 1 h. Except for volatile fatty acids (VFAs), comparatively little total nitrogen (TN), total organic carbon (TOC), and metal cations were released at the same time. Such results might favor further process of phosphorus recovery. VFAs were considerably released only at 50 degrees C. Acetic, butyric, and propionic acid were the most abundant components in turn and their releasing profiles exhibited good linear relationship with time (R2 = 0.9977, 0.9624, and 0.8908, respectively). The concentrations of Mg2+ and K+ increased with time and temperature during thermal treatment, but Ca2+ decreased. The release of Mg2+ and K+ agreed well with TP release (R2 = 0.9892 and 0.9476, respectively). Temperature in the experimental range had very little impact on the linear relationships, especially of Mg2+. Moreover, the parameter of mixed liquor suspended solids (MLSS) was found to be an important factor for thermal sludge treatment as the released ortho-P and total phosphorus (TP) at 50 degrees C increased more than one-fold when MLSS was increased from 4000 to 8000 mg/L.

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

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Christensen, Thomas Højlund; Guildal, T.


    The fate of total organic carbon, 32 elements (Al, Ag, As, Ba, Be, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, N, Na, Ni, P, Pb, S, Sb, Se, Sn, Sr, Ti, V, and Zn) and 4 groups of organic pollutants (linear alkylbenzene sulfonates, bis(2-ethylhexyl)phthalate, polychlorinated biphenyl...... and polycyclic aromatic hydrocarbons) in a conventional wastewater treatment plant were assessed. Mass balances showed reasonable closures for most of the elements. However, gaseous emissions were accompanied by large uncertainties and show the limitation of mass balance based substance flow analysis. Based...... the organic pollutants were effectively destroyed by both biological and thermal processes. Side streams from the sludge treatment process (dewatering and incineration) back to the wastewater treatment represented less than 1% of the total volume entering the wastewater treatment processes, but represented...


    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik


    Full Text Available This paper presents a method for calibration of activated sludge model with the use of computer program BioWin. Computer scheme has been developed on the basis of waste water treatment plant operating in the sequential – flow technology. For calibration of the activated sludge model data of influent and treated effluent from the existing object were used. As a result of conducted analysis was a change in biokinetic model and kinetic parameters parameters of wastewater treatment facilities. The presented method of study of the selected parameters impact on the activated sludge biokinetic model (including autotrophs maximum growth rate, the share of organic slurry in suspension general operational, efficiency secondary settling tanks can be used for conducting simulation studies of other treatment plants.

  12. Microbial community changes in biological phosphate-removal systems on altering sludge phosphorus content

    NARCIS (Netherlands)

    Liu, WT; Linning, KD; Nakamura, K; Mino, T; Matsuo, T; Forney, LJ

    Biomarkers (respiratory quinones and cellular fatty acids) and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes were used to characterize the microbial community structure of lab-scale enhanced biological phosphate-removal (EBPR) systems in response to altering sludge

  13. Combined removal of sulfur compounds and nitrate by autotrophic denitrication in bioaugmented activated sludge system

    NARCIS (Netherlands)

    Manconi, I.; Carucci, A.; Lens, P.N.L.


    An autotrophic denitrification process using reduced sulfur compounds (thiosulfate and sulfide) as electron donor in an activated sludge system is proposed as an efficient and cost effective alternative to conventional heterotrophic denitrification for inorganic (or with low C/N ratio) wastewaters

  14. Parameter subset selection for the dynamic calibration of activated sludge models (ASMs): experience versus systems analysis

    DEFF Research Database (Denmark)

    Ruano, MV; Ribes, J; de Pauw, DJW


    In this work we address the issue of parameter subset selection within the scope of activated sludge model calibration. To this end, we evaluate two approaches: (i) systems analysis and (ii) experience-based approach. The evaluation has been carried out using a dynamic model (ASM2d) calibrated...

  15. Integrated nonthermal treatment system study

    Energy Technology Data Exchange (ETDEWEB)

    Biagi, C.; Bahar, D.; Teheranian, B.; Vetromile, J. [Morrison Knudsen Corp. (United States); Quapp, W.J. [Nuclear Metals (United States); Bechtold, T.; Brown, B.; Schwinkendorf, W. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States); Swartz, G. [Swartz and Associates (United States)


    This report presents the results of a study of nonthermal treatment technologies. The study consisted of a systematic assessment of five nonthermal treatment alternatives. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The alternatives considered were innovative nonthermal treatments for organic liquids and sludges, process residue, soil and debris. Vacuum desorption or various washing approaches are considered for treatment of soil, residue and debris. Organic destruction methods include mediated electrochemical oxidation, catalytic wet oxidation, and acid digestion. Other methods studied included stabilization technologies and mercury separation of treatment residues. This study is a companion to the integrated thermal treatment study which examined 19 alternatives for thermal treatment of MLLW waste. The quantities and physical and chemical compositions of the input waste are based on the inventory database developed by the US Department of Energy. The Integrated Nonthermal Treatment Systems (INTS) systems were evaluated using the same waste input (2,927 pounds per hour) as the Integrated Thermal Treatment Systems (ITTS). 48 refs., 68 figs., 37 tabs.

  16. Tratamento térmico de lodo anaeróbio com utilização do biogás gerado em reatores UASB: avaliação da autossustentabilidade do sistema e do efeito sobre a higienização e a desidratação do lodo Thermal treatment of anaerobic sludge utilizing biogas produced in UASB reactors: evaluation of system self-sustainability and the effect on sludge hygienization and dehydration

    Directory of Open Access Journals (Sweden)

    Eduardo Sales Machado Borges


    Full Text Available O presente trabalho objetiva avaliar a eficiência do biogás gerado em reatores UASB como fonte de energia para higienização térmica do lodo excedente, atentando-se ainda para a autossustentabilidade do sistema e para a avaliação do desaguamento do lodo tratado termicamente. Foi desenvolvido em um aparato experimental em escala de demonstração constituído de reator UASB, reservatório de biogás, reator térmico e leitos de secagem. A autossustentabilidade foi verificada por meio de balanço térmico teórico e de testes experimentais de higienização térmica. Estes testes indicaram que o aproveitamento da energia térmica do biogás foi suficiente para aquecer o lodo em temperaturas de 55 a 65ºC, durante três a cinco horas, possibilitando a completa eliminação de ovos viáveis de helmintos. No entanto, o processo de desidratação se mostrou muito mais difícil para o lodo tratado termicamente.The objective of this research was to determine how effectively biogas produced in UASB reactors could be used as a source of heat for the thermal hygienization of excess anaerobic sludge, whether the system can operate on a self-sustained basis and how the dehydration of the thermally treated sludge behave. The experiments were conducted in a demonstration-scale setup comprising UASB reactor, biogas holder, thermal reactor and sludge drying beds. The self-sustainability of the system was evaluated by the systemâ€TMs theoretical thermal balance and by experimental hygienization tests. These tests indicated that the recovery of thermal energy from the biogas was sufficient to heat the sludge at temperatures in the range of 55 to 65ºC, for three to five hours, allowing the complete elimination of viable helminth eggs. However, the dehydration process showed to be much more difficult for the thermally treated sludge.

  17. Activated sludge model No. 3

    DEFF Research Database (Denmark)

    Gujer, W.; Henze, M.; Mino, T.


    The Activated Sludge Model No. 3 (ASM3) can predict oxygen consumption, sludge production, nitrification and denitrification of activated sludge systems. It relates to the Activated Sludge Model No. 1 (ASM1) and corrects for some defects of ASM I. In addition to ASM1, ASM3 includes storage...

  18. Sustainability of Domestic Sewage Sludge Disposal

    Directory of Open Access Journals (Sweden)

    Claudia Bruna Rizzardini


    Full Text Available Activated sludge is now one of the most widely used biological processes for the treatment of wastewaters from medium to large populations. It produces high amounts of sewage sludge that can be managed and perceived in two main ways: as a waste it is discharged in landfill, as a fertilizer it is disposed in agriculture with direct application to soil or subjected to anaerobic digestion and composting. Other solutions, such as incineration or production of concrete, bricks and asphalt play a secondary role in terms of their degree of diffusion. The agronomical value of domestic sewage sludge is a proved question, which may be hidden by the presence of several pollutants such as heavy metals, organic compounds and pathogens. In this way, the sustainability of sewage sludge agricultural disposal requires a value judgment based on knowledge and evaluation of the level of pollution of both sewage sludge and soil. The article analyzed a typical Italian case study, a water management system of small communities, applying the criteria of evaluation of the last official document of European Union about sewage sludge land application, the “Working Document on Sludge (3rd draft, 2000”. The report brought out good sewage sludge from small wastewater treatment plants and soils quality suggesting a sustainable application.

  19. Physical chemical properties of sludges of a chemical treatment of boilers feed water and ways of their utilization

    Directory of Open Access Journals (Sweden)

    T. Krasnenko


    Full Text Available Water is a necessary process for TPP power plant operation. To the power station, in the production of electricity and heat as a result of the preparation of large amounts of water to compensate for losses associated with the release of process steam for production, produce large quantities of waste water treatment - water treatment chemical sludge (WTCS.

  20. Implementation of co-digestion and sludge management systems in Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Di Berardino, Santino [INETI/DER, Lisboa (Portugal)


    A solution based on sludge and Olive oil mill effluent (OME) co-digestion, coupled with a management plan, has been implemented, to treat and dispose safely, the mixed residues, into the natural forest and agricultural land. The mixture of up to 25% OME to the sludge improved anaerobic degradation of phenols and fats. High density fat compounds, present in OME, enhanced aggregation, settling and acetoclastic activity of anaerobic sludge. The full scale unit, obtained by modification of a cold digester, allowed to set-up a low capital cost system. The system produced large quantity of biogas and electric energy. Anaerobic degradation of the mixture improved fertilizing properties, making feasible land application of the digested mixture. Regional plan based in Geographical Information System (GIS) selected 800 ha of adequate land area for application near the WWTP. The experience is technically and economically successful. Main incomes are provided by energy use and OME charge. Sludge application in local agriculture does not generate any income, but eliminated landfill costs and reduced transportation costs.

  1. Heat treatment of processing sludge of ornamental rocks: application as pozzolan in cement matrices

    Directory of Open Access Journals (Sweden)

    J.G. Uliana

    Full Text Available The sector of ornamental rocks produces significant volume of waste during the sawing of the blocks and demand to find ways to recycle, given its environmental impact. Considering the possibilities of use of industrial by-products as mineral admixtures, aiming at sustainable development in the construction industry, this paper aims to study the performance of the processing sludge of ornamental rocks and grinding after heat treatment, based on their potential application as partial substitute for cement. The residue was characterized, cast and milled to produce glassy material. Was analyzed the mechanical performance and pozzolanic activity with partial replacement of cement by waste in natural condition and after heat treatment in mortars for comparison. The results were promising, so it was possible to verify that after heat treatment, the treated waste is presented as a material with pozzolanic characteristics.

  2. Biological nutrient removal wastewater treatments and sewage sludge anaerobic mesophilic digestion performances. (United States)

    Bolzonella, D; Innocenti, L; Cecchi, F


    The paper deals with the performances of the mesophilic anaerobic digestion treatment of sewage sludge from a full scale BNR process without primary settling (nominally 300,000 PE). A relation between the activated sludge observed yields, Y(obs), and the anaerobic digester performance was preliminarily found: for values of Y(obs) of 0.25 kgVSS/kgCOD the anaerobic digester specific gas production showed the best performances (0.22 m3/kgVS(fad)). This has to be confirmed with wider future studies. It was also shown the level of sludge pre-thickening to be reached for the self-sustaining warming of the digester also in wintertime. According to the energetic balance and to a comparison with an aerobic stabilisation process, it was pointed out as when a co-generation unit for heat and energy production was introduced about 3.4 kWh/PE y of energy were produced in the anaerobic digestion process. On the other hand, 4.3 kWh/PE y were spent if an aerobic stabilisation process was applied. The economic assessment, carried out on the basis of the energy balances, showed that the anaerobic digestion is always economically advantageous if compared to aerobic stabilisation processes, also for small WWTPs. According to the energetic evaluations an environmental balance was assessed, in terms of CO2 emissions. The difference between anaerobic and aerobic processes was about 5.3 kgCO2/PE y in favour of anaerobic processes application.

  3. Comparison of methods for the isolation of mycobacteria from water treatment plant sludge. (United States)

    Makovcova, Jitka; Babak, Vladimir; Slany, Michal; Slana, Iva


    Nontuberculous mycobacteria (NTM) are ubiquitous organisms in all natural ecosystems, including water environments. Several of these species are potential pathogens which affect human health. NTM most commonly cause pulmonary, skin or soft tissue infections. Primary sludge obtained from the water treatment plants of four drinking water reservoirs were subjected to analysis for mycobacteria. Five decontamination methods (5% oxalic acid, modified Petroff, HCl-NaOH, N-acetyl-L-cysteine-sodium hydroxide and 0.05% cetylpyridinium chloride), three growth media (Herrold's egg yolk medium with and without the antibiotic cocktail PANTA and Löwenstein-Jensen medium with sodium pyruvate) and three incubation temperatures (25, 30 and 37 °C) for isolation of mycobacteria were compared in the analysis of 18 sludge samples. To evaluate examined methods, the overall positive, negative, and contamination rate, and these rates in respect to localities are taken into account. Statistical analysis demonstrated that the best combination for the recovery of mycobacteria with the minimum number of contaminating microorganisms is 5% oxalic acid decontamination cultured on Herrold's egg yolk medium with the antibiotic cocktail PANTA at 25 °C. The least suitable is N-acetyl-L-cysteine-sodium hydroxide decontamination cultured on Löwenstein-Jensen medium with sodium pyruvate at 25 °C. From 18 sludge samples we isolated 27 mycobacterial species or groups; Mycobacterium algericum, M. arabiense, M. heraklionense, M. minnesotense, M. moriokaense, M. salmoniphilum and M. vulneris were isolated from the natural water environment for the first time. Because the natural water environment is the main source of potentially pathogenic mycobacteria for humans, it is important to direct particular focus to newly described mycobacterial species.

  4. Thermal pre-treatment of primary and secondary sludge at 70 °C prior to anaerobic digestion

    DEFF Research Database (Denmark)

    Skiadas, Ioannis; Gavala, Hariklia N.; Lu, J.


    In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared tothermophilic digestion, mainly because of the lower energy requirements and higher stability of the process. However, the thermophilic anaerobic digestion process is usually characterised by accelerated...... studyinvestigates the effect of the pre-treatment at 70 °C on thermophilic (55 °C) anaerobic digestion of primaryand secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondarysludge at 70 °C enhanced the removal of organic matter and the methane production during...... the subsequentanaerobic digestion step at 55 °C. It also greatly contributed to the destruction of pathogens present inprimary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic stepsuggesting that the same efficiencies in organic matter removal and methane recovery could be obtained...

  5. The Assessment of Water Treatment Plant Sludge Properties and the Feasibility of Its Re-use according to Environmental Standards: Shahid Beheshti Water Treatment Plant Case Study, Hamadan

    Directory of Open Access Journals (Sweden)

    H. Pourmand


    Full Text Available Introduction & Objectives: Water treatment leads to produce large volumes of sludges in water treatment plants which are considered as solid waste, and should be managed appropriately and logically to avoid bioenvironmental effects. Materials & Methods: In this cross-sectional study, the required samples were taken from the sludge of Shahid Beheshti water treatment plant to assay physical and chemical characteristics during one year from summer, autumn and winter 93 until spring 94. Sampling and testing procedures were full fit according to standard methods. Results: The average concentration of total solids parameters (TSS, total suspended solids (TSS, and total dissolved solids (TDS were 22346, 21350 and 1005 mg/L, respectively. Among the heavy metals, aluminum, iron, manganese and zinc have the highest concentrations with the values of 1400, 956, 588 and 100 mg per kg of dry solids, respectively. The measured concentrations for cadmium were also higher than the permissible limits for agricultural purposes and discharges into the environment. The average concentrations of nickel were more than the recommended standard for industrial, agricultural and parkland application purposes. The concentrations were also slurry higher than the dry sludge. Conclusion: According to the past studies and results of this study, it could be concluded that contamination of heavy metals in sludge and slurry samples are more than dried sludge, .Therefore, if they are discharged into the environment, it is better to be disposed as dry sludges. Furthermore, because these types of waste sludges are routinely disposed in the environment, it is recommended to take the routine samples in order to measure the heavy metals and other relevant parameters contents of sludge before discharging it. (Sci J Hamadan Univ Med Sci 2016; 23 (1:57-64

  6. Sludge hygienization: Helminth eggs destruction by lime treatment Ascaris eggs as model

    Energy Technology Data Exchange (ETDEWEB)

    Banas, S.; Schwartzbrod, J. [Lab. de Chimie Physique et Microbiologie de l' Environnement, Nancy (France); Remy, M. [Lhoist, on behalf of the European Lime Assoication (EuLA), Bruessel (Germany); Boehm, R. [Univ. Hohenheim, Stuttgart (Germany); Verfuerden, M. [Fels-Werke GmbH, im Namen des Bundesverbandes der Deutschen Kalkindustrie (BVK), Koeln (Germany)


    Most pathogens in the raw sewage are concentrated into the sewage sludge. They can be separated into four categories: viruses, bacteria, protozoa and larger parasites such as human roundworms, tapeworms and liver flukes. Such micro-organisms can cause disease in humans, the transmission occurring in several ways e.g. by inhaling sludge aerosols or dust, by eating vegetables or fruits contaminated by sludge, drinking water contaminated by run-off or by eating meat from livestock infected by grazing pastures fertilised with sludge. The presence of helminth eggs in urban sludge may constitute a sanitary risk when used as agricultural fertiliser. To avoid any contamination, the efficiency of a certain number of sludge hygienization processes must be tested. One of these involves decontamination with quicklime. The Ascaris egg inactivation by liming with lime milk, slaked lime and quicklime is studied in a series of sludges coming from slaughterhouses. (orig.)

  7. Microbiologia de sistema de lodos ativados e sua relação com o tratamento de efluentes industriais: a experiência da Cetrel Activated sludge system microbiology and its relationship with the industrial effluents treatment: the experience of the Cetrel

    Directory of Open Access Journals (Sweden)

    Gisele Santos Silva de Oliveira


    Full Text Available Buscou-se, neste trabalho, caracterizar a comunidade microbiana de lodos ativados dos tanques de aeração (TA-2, TA-3 e TA-4 da estação de tratamento de efluentes (ETE da Cetrel e correlacioná-la com parâmetros físico-químicos de processo, bem como avaliar o impacto do efluente industrial (EI bruto na estrutura da comunidade do lodo. Adicionalmente, foi verificada a existência de possíveis correlações entre a qualidade do efluente tratado final (ETF e a comunidade do lodo para identificar algum grupo biológico que pudesse ser usado como bioindicador desta ETE. Os principais grupos encontrados nos TA foram ciliados (livre natantes, de vida livre e pedunculados e flagelados. Verificou-se que altas cargas de DBO e DQO no EI afetam negativamente o sistema, especialmente o grupo dos ciliados, que foram os melhores indicadores da elevada eficiência da ETE. O TA-2 mostrou ser o tanque mais estável e eficiente.The purpose of this study was to characterize the microbial community of activated sludge in the aeration tanks (AT-2, AT-3 and AT-4 from the Cetrel wastewater treatment plant (WWTP and to correlate it to physical-chemical parameters, as well as to assess the impact of the raw industrial effluent (IE on the activated sludge community. Additionally, it was verified the relationship between the treated effluent (TE quality and the biological groups to determinate indicators of the WWTP efficiency. Ciliated protozoa (free-swimming, crawler and sessile and flagellates were the main biological groups found in the TA. It was demonstrated that high IE-BOD and -COD loads have a negative influence on the system, especially on the ciliated protozoa, which was the best indicator of high efficiency of the WWTP. The AT-2 was the more stable and efficient.

  8. Performance of a system with full- and pilot-scale sludge drying reed bed units treating septic tank sludge in Brazil. (United States)

    Calderón-Vallejo, Luisa Fernanda; Andrade, Cynthia Franco; Manjate, Elias Sete; Madera-Parra, Carlos Arturo; von Sperling, Marcos


    This study investigated the performance of sludge drying reed beds (SDRB) at full- and pilot-scale treating sludge from septic tanks in the city of Belo Horizonte, Brazil. The treatment units, planted with Cynodon spp., were based on an adaptation of the first-stage of the French vertical-flow constructed wetland, originally developed for treating sewage. Two different operational phases were investigated; in the first one, the full-scale unit was used together with six pilot-scale columns in order to test different feeding strategies. For the second phase, only the full-scale unit was used, including a recirculation of the filtered effluent (percolate) to one of the units of the French vertical wetland. Sludge application was done once a week emptying a full truck, during 25 weeks. The sludge was predominantly diluted, leading to low solids loading rates (median values of 18 kgTS m(-2) year(-1)). Chemical oxygen demand removal efficiency in the full-scale unit was reasonable (median of 71%), but the total solids removal was only moderate (median of 44%) in the full-scale unit without recirculation. Recirculation did not bring substantial improvements in the overall performance. The other loading conditions implemented in the pilot columns also did not show statistically different performances.

  9. Rational Basis for Designing Horizontal-Flow Anaerobic Immobilized Sludge (HAIS Reactor for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Zaiat M.


    Full Text Available The conception and development on a rational basis of a new configuration of anaerobic fixed-bed bioreactor for wastewater treatment, the horizontal-flow anaerobic immobilized sludge (HAIS reactor, is presented. Such a reactor containing immobilized sludge in polyurethane foam matrices was first assayed for treating paper industry wastewater. A very short start-up period was observed and the reactor achieved stable operation by the eighth day. Afterwards, fundamental aspects of the process were investigated in order to obtain a rational basis for HAIS reactor design. A sequence of experiments was carried out for evaluating the cell wash-out from polyurethane foam matrices, the liquid-phase mass transfer coefficient and the intrinsic kinetic parameters, besides the hydrodynamic flow pattern of the reactor. The knowledge of such fundamental phenomena is useful for improving the reactor?s design and operation. Besides, these fundamental studies are essential to provide parameters for simulation and optimization of processes that make use of immobilized biomass


    Directory of Open Access Journals (Sweden)



    Full Text Available The purpose of this study was to determine the content of metals elements in the sludge of Ibn Ziad sewage treatment plant of Constantine in order to preserve its quality for subsequent use in agriculture. The use of X-ray fluorescence spectroscopy allowed us to identify the following constituents in this mud: Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Ba, Pb. These elements represent 49.82 % of the total mass of the sludge. The elements present with regulated content limit are chromium, copper, nickel, lead and zinc. They occur respectively with the following concentrations: 0.27 mg·g-1, 0.48 mg·g-1, 0.11 mg·g-1, 0.35 mg·g-1 and 2.70 mg·g-1. We have achieved an extraction for evaluating the concentration of the dissolved nitrate ions, the chemical oxygen demand (COD, and pH. The nitrate ions were transformed into sodium paranitrosalicylate to be dosed by ultraviolet-visible (UV-Vis spectroscopy at 420 nm. The concentration measured was 0.12 mg·g-1. The measuring of the COD issued a value of 0.45 mg·g-1. pH was 7.1.

  11. Settling velocity of sludge in coagulation flocculation treatment of leachate using ferric chloride and chitosan (United States)

    Aziz, Hamidi Abdul; Ramli, Siti Fatihah


    Leachate is a highly contaminated wastewater which needs to be treated before being discharged to the environment. This is due to the concern that it may cause severe impacts on the environment. One of the well-known treatments that have been adapted for decades for treating leachate is the coagulation and flocculation processes. Coagulation and flocculation processes involve the addition of chemical or natural coagulant in order to destabilize the particles and remove the contaminants present. The rate or performance of chemical/natural coagulant use can be evaluated by determining the sludge settling rate during the flocculation process. This study emphasizes on the effect of Chitosan as natural coagulant aid/polymer in improving the settling rate of flocs after the flocculation process. After a series of experiments, Chitosan as a polymer showed a potential and gave a satisfying results as it improved the sludge settling velocity from 0.57 cm/min, when FeCl3 (chemical coagulant) was used independently to 0.69 cm/min when Chitosan was applied as a coagulant aid. Moreover, Chitosan also increased the floc size to 198. 5 µm compared to 83.3 μm when FeCl3 was used alone. The improvement in terms of settling velocity and size of flocs was due higher molecular weight of Chitosan which provides a long chain for particle attachments. With this ability, Chitosan had a greater potential in increasing the performance of flocculation.

  12. Wastewater treatment--adsorption of organic micropollutants on activated HTC-carbon derived from sewage sludge. (United States)

    Kirschhöfer, Frank; Sahin, Olga; Becker, Gero C; Meffert, Florian; Nusser, Michael; Anderer, Gilbert; Kusche, Stepan; Klaeusli, Thomas; Kruse, Andrea; Brenner-Weiss, Gerald


    Organic micropollutants (MPs), in particular xenobiotics and their transformation products, have been detected in the aquatic environment and the main sources of these MPs are wastewater treatment plants. Therefore, an additional cleaning step is necessary. The use of activated carbon (AC) is one approach to providing this additional cleaning. Industrial AC derived from different carbonaceous materials is predominantly produced in low-income countries by polluting processes. In contrast, AC derived from sewage sludge by hydrothermal carbonization (HTC) is a regional and sustainable alternative, based on waste material. Our experiments demonstrate that the HTC-AC from sewage sludge was able to remove most of the applied MPs. In fact more than 50% of sulfamethoxazole, diclofenac and bezafibrate were removed from artificial water samples. With the same approach carbamazepine was eliminated to nearly 70% and atrazine more than 80%. In addition a pre-treated (phosphorus-reduced) HTC-AC was able to eliminate 80% of carbamazepine and diclofenac. Atrazine, sulfamethoxazole and bezafibrate were removed to more than 90%. Experiments using real wastewater samples with high organic content (11.1 g m(-3)) succeeded in proving the adsorption capability of phosphorus-reduced HTC-AC.

  13. Advanced thermal hydrolysis: optimization of a novel thermochemical process to aid sewage sludge treatment. (United States)

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


    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.

  14. Impact of sludge deposition on biodiversity. (United States)

    Manzetti, Sergio; van der Spoel, David


    Sludge deposition in the environment is carried out in several countries. It encompasses the dispersion of treated or untreated sludge in forests, marsh lands, open waters as well as estuarine systems resulting in the gradual accumulation of toxins and persistent organic compounds in the environment. Studies on the life cycle of compounds from sludge deposition and the consequences of deposition are few. Most reports focus rather on treatment-methods and approaches, legislative aspects as well as analytical evaluations of the chemical profiles of sludge. This paper reviews recent as well as some older studies on sludge deposition in forests and other ecosystems. From the literature covered it can be concluded that sludge deposition induces two detrimental effects on the environment: (1) raising of the levels of persistent toxins in soil, vegetation and wild life and (2) slow and long-termed biodiversity-reduction through the fertilizing nutrient pollution operating on the vegetation. Since recent studies show that eutrophication of the environment is a major threat to global biodiversity supplying additional nutrients through sludge-based fertilization seems imprudent. Toxins that accumulate in the vegetation are transferred to feeding herbivores and their predators, resulting in a reduced long-term survival chance of exposed species. We briefly review current legislation for sludge deposition and suggest alternative routes to handling this difficult class of waste.

  15. Microbiology of the active sludge as a system to improve the effluents quality in the wastewater treatment plants; La microbiologia del fango activo como sistema para mejorar la calidad de los efluentes en las depuradoras de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, E.; Reina, E.; Fernandez, N.


    Grupo Bioindicacion Sevilla (GBS) is a Spanish group of professionals interested in microbiology. GBS celebrates an annual activity about transfer of technology on microbiology of the active sludge, which fifth edition was celebrated in 2008 with the participation of different universities (Complutense de Madrid, Politecnica de Valencia y Barcelona, etc.) and public and private water companies (DAM, Aguas de Valencia, Aqualia, Emasesa, Emacsa...), and will celebrate again in Seville the next October. During this conference, the GBS group informs about the inter-laboratories exercises too, which last results are showed in this article. (Author) 9 refs.

  16. Investigation of extracellular polymer substances (EPS) and physicochemical properties of activated sludge from different municipal and industrial wastewater treatment plants. (United States)

    Peng, Ge; Ye, Fenxia; Li, Ying


    This paper examines the chemical constituents of extracellular polymeric substances (EPS) and physicochemical properties of eight different sludge flocs from seven full-scale wastewater treatment plants. The physicochemical properties included floc properties (floc size, turbidity and effluent suspended solids (ESS) content of the supernatant), sludge volume index, capillary suction time and specific resistance to filtration. The relationships between the chemical constituents of EPS and the flocculation, settleability and dewaterability of sludge flocs were also assessed. The results showed that higher amounts of EPS were found in the municipal sludge flocs than in the industrial sludges. The content of tightly bound EPS (TB-EPS) was much greater than that of loosely bound EPS (LB-EPS). The amounts of total EPS, LB-EPS, TB-EPS and protein in LB-EPS were strongly related to ESS. The ratios of total protein to EPS and total carbohydrate to EPS showed positive correlation to the flocs size. It was surprising that there was no correlation between settleability or dewaterability and the chemical constituents of EPS.

  17. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China. (United States)

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan


    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.

  18. Levels and distribution patterns of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China. (United States)

    Zeng, Lixi; Wang, Thanh; Ruan, Ting; Liu, Qian; Wang, Yawei; Jiang, Guibin


    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Evaluation and Source Apportionment of Heavy Metals (HMs in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs in Shanxi, China

    Directory of Open Access Journals (Sweden)

    Baoling Duan


    Full Text Available 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.


    Directory of Open Access Journals (Sweden)

    Magdalena Filkiewicz


    Full Text Available According to the National Waste Management Plan 2014 (NWMP 2014 recommended method of utilization of sewage sludge is using it for agricultural purposes or for land reclamation. The sludge is characterized by a high content of organic substances, microelements and biogenic compounds, through which sewage sludge possess high soil formation and fertilization properties. It is assumed that in 2020 approximately 30% of the sludge production will be used for agricultural purposes, while 15% will be used for land reclamation. We have to remember that prior to the introduction of sludge into the ground, security, health and chemical requirements should be met. In order to use the sludge for agricultural purposes, the process of their disposal should be previously carried out e.g. Autoheated Thermophilic Aerobic Digestion (ATAD. It allows for hygienisation of sewage sludge and reducing the heavy metal content. As a result, processed sewage sludge is characterized by the presence of heavy metals in amounts which do not exceed the standards. It is also deprived of microorganisms. The stabilized sludge is characterized by high phosphorus and calcium content. Therefore there is possibility to use the examined sludge in agriculture.

  1. Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

    Directory of Open Access Journals (Sweden)

    Mariana Manzoni Maroneze


    Full Text Available Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mg sludge mg chemical oxygen demand−¹, resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 g iodine 100 g−¹, unsaturation degree of ~75 % and a cold filter plugging point of 5 ºC.

  2. Removal of polycyclic aromatic hydrocarbons (PAHs) from textile dyeing sludge by ultrasound combined zero-valent iron/EDTA/Air system. (United States)

    Man, Xiaoyuan; Ning, Xun-An; Zou, Haiyuan; Liang, Jieying; Sun, Jian; Lu, Xingwen; Sun, Jiekui


    This paper proposes a combined ultrasound (US) and zero-valent iron/EDTA/Air (ZEA) system to remove polycyclic aromatic hydrocarbons (PAHs) from textile dyeing sludge. The removal efficiencies of 16 PAHs using ZEA, US/Air (air injected into the US process), and US/ZEA treatments were investigated, together with the effects of various operating parameters. The enhanced mechanisms of US and the role of reactive oxygen species (ROS) in removing PAHs in the US/ZEA system were explored. Results showed that only 42.5% and 32.9% of ∑16 PAHs were removed by ZEA and US/Air treatments respectively, whereas 70.1% were removed by US/ZEA treatment, (with favorable operating conditions of 2.0 mM EDTA, 15 g/L ZVI, and 1.08 w/cm3 ultrasonic density). The US/ZEA system could be used with a wide pH range. US led to synergistic improvement of PAHs removal in the ZEA system by enhancing sludge disintegration to release PAHs and promoting ZVI corrosion and oxygen activation. In the US/ZEA system, PAHs could be degraded by ROS (namely OH, O2-/HO2, and Fe(IV)) and adsorbed by ZVI, during which the ROS made the predominant contribution. This study provides important insights into the application of a US/ZEA system to remove PAHs from sludge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of Cambi Thermal Hydrolysis Process-Anaerobic digestion treatment on concentrations on phthalate plasticisers in wastewater sludge (United States)

    The impact of the recently implemented Cambi Thermal Hydrolysis Process™-Anaerobic Digestion (TH-AD) solids treatment method on concentrations of 4 phthalate plasticisers in wastewater sludge samples was explored in this study. Samples were analysed for diisononyl phthalate (DiNP), diisodecyl phthal...


    Directory of Open Access Journals (Sweden)

    Happy Mulyani


    Full Text Available The objectives of this research are to study about influence of calcium hypochlorite dosage adjustment on tapioca wastewater chlorination toward efficiency of activated sludge treatment especially at MLVSS profile and percentage of COD removal. This research mainly divided into pre-chlorination and activated sludge treatment. Pre-chlorination taken place for 60 minutes at pH 8. The variation of calcium hypochlorite dosages which used are 58, 59, and 60 mg/L. Pre-chlorination effluent with no free chlorine residual then becomes activated sludge treatment influent. Sampling has done each aeration time interval 0, 2, 4, and 6 hour for analysis of COD and MLVSS content. Research result generally shows that addition of aeration time for each variation of calcium hypochlorite dosage will increase MLVSS and decrease COD content. Smallest value of COD effluent could achieved in the activated sludge treatment with calcium hipochlorite dosage 60 mg/L addition at influent during 4 hours aeration time. Addition of 58 mg/l calcium hypochlorite results highest MLVSS and percentage of COD removal.

  5. Verification of an alternative sludge treatment process for pathogen reduction at two wastewater treatment plants in Victoria, Australia. (United States)

    Irwin, R; Surapaneni, A; Smith, D; Schmidt, J; Rigby, H; Smith, S R


    At South East Water wastewater treatment plants (WwTPs) in Victoria, Australia, biosolids are stockpiled for three years in compliance with the State guidelines to achieve the highest pathogen reduction grade (T1), suitable for unrestricted use in agriculture and landscaping. However, extended stockpiling is costly, may increase odour nuisance and greenhouse gas emissions, and reduces the fertiliser value of the biosolids. A verification programme of sampling and analysis for enteric pathogens was conducted at two WwTPs where sludge is treated by aerobic and anaerobic digestion, air drying (in drying pans or solar drying sheds) and stockpiling, to enumerate and, if present, monitor the decay of a range of enteric pathogens and parasites. The sludge treatment processes at both WwTPs achieved T1 grade biosolids with respect to prescribed pathogenic bacterial numbers (3 log 10 enteric virus reduction after a storage period of one year. No Ascaris eggs were detected in the influent to the WwTPs, confirming previous studies that the presence of helminth infections in Victoria is extremely low and that Ascaris is not applicable as a control criterion for the microbiological quality of biosolids in the region.

  6. Operator assisted optimization of sludge dewatering

    DEFF Research Database (Denmark)

    Grüttner, Henrik


    On a municipal wastewater treatment plant using a decanter-centrifuge for dewatering of anaerobic digested sludge an operator assisting system for sludge dewatering was developed. The system is based on a database used to collect data on sludge properties and operational conditions which is added...... by the operator. By graphical presentation and an advisory service these data are used to support the operator in his dewatering operations and to secure a running optimization of the sludge dewatering. Evaluations show that this system is a useful tool for data collection and presentation and that the data...... collected seem to reflect the actual situation at the plant. In the future such systems are expected to be used as tools for education of operators, transfer of knowledge from one operator to another and for a continuous optimization of dewatering operations. (A)...

  7. Fecal sludge management in developing urban centers: a review on the collection, treatment, and composting. (United States)

    Odey, Emmanuel Alepu; Li, Zifu; Zhou, Xiaoqin; Kalakodio, Loissi


    The problems posed by fecal sludge (FS) are multidimensional because most cities rapidly urbanize, which results in the increase in population, urban settlement, and waste generation. Issues concerning health and waste treatment have continued to create alarming situations. These issues had indeed interfered with the proper steps in managing FS, which contaminates the environment. FS can be used in agriculture as fertilizer because it is an excellent source of nutrients. The recent decline in crop production due to loss of soil organic component, erosion, and nutrient runoff has generated interest in the recycling of FS into soil nutrients through stabilization and composting. However, human feces are considerably liable to spread microorganisms to other persons. Thus, sanitation, stabilization, and composting should be the main objectives of FS treatment to minimize the risk to public and environmental health. This review presents an improved FS management (FSM) and technology option for soil amendment that is grouped into three headings, namely, (1) collection, (2) treatment, and (3) composting. On the basis of the literature review, the main problems associated with the collection and treatment of FS, such as inadequate tools and improper treatment processes, are summarized, and the trends and challenges that concern the applicability of each of the technologies in developing urban centers are critically reviewed. Stabilization during pretreatment before composting is suggested as the best method to reduce pathogens in FS. Results are precisely intended to be used as a support for decisions on policies and strategies for FSM and investments for improved treatment facilities.

  8. Modern sewage sludge treatment processes: From elimination of constituents to product recycling - sewage sludge utilisation. Final report; Moderne Abwasserreinigung - von der Eliminierung der Inhaltsstoffe zur Produktgewinnung - Hier: Klaerschlammverwertung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kempter-Regel, B.; Trick, I.


    The extended treatment of sewage sludge accumulated in municipal sewage plants was investigated in this study. The intention was both the enhancement of the biological degradation of sewage sludge and the removal of ammonium from sludge water. For this purpose an aerobic treatment with fungi respectively with a lysobacter spec. screened for that purpose was attached to an existing two stage high performance digestion which already converts 50-55% of the organic of sewage sludge to biogas. The output of the aerobic treatment was led back to the anaerobic digestor. Thus an enhancement of the biogasyield was achieved up until 0,5 l/g VOS{sub input}. The sludge water gained by filtration from the second stage of the high performance digestion was used for removal of ammonium. The ammonium was removed from the sludge water with a new filtration process, the so called membrane contractor. Thus both the ammonium was gained and recycled as a resource, and the nitrification and the denitrification of the municipal sewage plant are relieved. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Ragsdale, Jr, Robert G. [Clemson Univ., SC (United States)


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

  10. Engineering evaluation of solids/liquids separation processes applicable to sludge treatment project

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.


    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.

  11. Study of the viscosity behaviour of glasses obtained from urban wastewater treatment sludges from Egypt using hot stage microscopy (United States)

    Garcia-Valles, M.


    us to determine the working temperatures of the four glasses, ranging from 926 and to 1419 °C, depending on the type of forming process used. In all glass samples the viscosity-temperature curves have similar characteristics, but for higher viscosities a separation among the different viscosity-temperature curves occurs. This different behaviour is associated to chemical composition: Ca-rich silica aluminum melt, present low viscosity at low temperatures, > P2O5 content, the nucleation of a more refractory phosphate phase occurs. In order to obtain the original glasses working conditions (necessary for possible industrial applications) are used the Vogel-Fulcher-Tammann equation: a) upper and lower annealing temperatures of the samples are similar for the different glasses and ranging between 595-641 °C and 671-701 °C respectively; b) working temperature range from 917-1307 °C for the sample E-02, and 925-1503 °C for the sample E-04, depending on the conformation system used. Finally, the forming and melting temperatures of the samples vary between 1307-1403 °C (E-02) and 1503-1550 °C (E-04). The results confirm that HSM is a good technique for studying the sludge vitrification process, and could provide important information for the possible industrial application. Acknowledgements This study is a contribution of the bilateral project A/030032/10 and CICYT TIN2008-02903. The analytical work was conducted at Research Consolidated Groups 2009SGR-0044 (Mineral Resources). Wastewater treatment plants at El-Sadat City, Alexandria, Abo-Rawash and Minufiya are acknowledged for sampling authorization and facilities. We express our acknowledgement to the technical support of the Scientific-Technical Service Unit of the University of Barcelona and the additional support of the Institute for Bioengineering of Catalonia (IBEC).

  12. Cost estimation and economical evaluation of three configurations of activated sludge process for a wastewater treatment plant (WWTP) using simulation (United States)

    Jafarinejad, Shahryar


    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.

  13. Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process. (United States)

    Xia, Yi; He, Pin Jing; Pu, Hong Xia; Lü, Fan; Shao, Li Ming; Zhang, Hua


    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.

  14. A direct comparison amongst different technologies (aerobic granular sludge, SBR and MBR) for the treatment of wastewater contaminated by 4-chlorophenol

    Energy Technology Data Exchange (ETDEWEB)

    Carucci, Alessandra [Department of Geoengineering and Environmental Technologies (DIGITA), University of Cagliari, P.zza d' Armi 1, 09100 Cagliari (Italy); Milia, Stefano, E-mail: [Department of Geoengineering and Environmental Technologies (DIGITA), University of Cagliari, P.zza d' Armi 1, 09100 Cagliari (Italy); Cappai, Giovanna; Muntoni, Aldo [Department of Geoengineering and Environmental Technologies (DIGITA), University of Cagliari, P.zza d' Armi 1, 09100 Cagliari (Italy)


    Environmental concern on chlorinated phenols is rising due to their extreme toxicity even at low concentrations and their persistency in water and soils. Since the high amount of published data often lacks in terms of uniformity, direct comparisons amongst different treatment technologies are very difficult, or even impossible. In this study, granular sludge developed in an acetate-fed Granular sludge Sequencing Batch Reactor (GSBR) was used for the aerobic degradation of low chlorinated 4-chlorophenol (4CP), with readily biodegradable sodium acetate (NaAc) as growth substrate. A conventional Sequencing Batch Reactor (SBR) and a Membrane BioReactor (MBR) were operated in parallel under the same 4CP influent concentrations and/or 4CP volumetric organic loading rates as the GSBR, in order to carry out a direct comparison in terms of 4CP removal efficiencies and specific removal rates, effluent quality, waste sludge production, system simplicity, land area requirement, start-up times, NaAc dosage as growth substrate and maximum applied 4CP volumetric organic loading rate. A decision matrix was built to define the best technology to suit different scenarios: the GSBR was proved to be the most suitable technology when system simplicity, low land area requirement and short start-up times were considered as critical parameters for decision making.

  15. Responses of Szarvasi-1 energy grass to sewage sludge treatments in hydroponics. (United States)

    Rév, Ambrus; Tóth, Brigitta; Solti, Ádám; Sipos, Gyula; Fodor, Ferenc


    Sewage sludge (SS) originating from communal wastewater is a hazardous material but have a potentially great nutritive value. Its disposal after treatment in agricultural lands can be a very economical and safe way of utilization once fast growing, high biomass, perennial plants of renewable energy production are cultivated. Szarvasi-1 energy grass (Elymus elongatus subsp. ponticus cv. Szarvasi-1), a good candidate for this application, was grown in hydroponics in order to assess its metal accumulation and tolerance under increasing SS amendments. The applied SS had a composition characteristic to SS from communal wastes and did not contain any toxic heavy metal contamination from industrial sludge in high concentration. Toxic effects was assessed in quarter strength Hoagland nutrient solution and only the two highest doses (12.5-18.75 g dm -3 ) caused decreases in root growth, shoot water content and length and stomatal conductance whereas shoot growth, root water content, chlorophyll concentration and the maximal quantum efficiency of photosystem II was unaffected. Shoot K, Ca, Mg, Mn, Zn and Cu content decreased but Na and Ni increased in the shoot compared to the unamended control. The nutritive effect was tested in 1/40 strength Hoagland solution and only the highest dose (12.5 g dm -3 ) decreased root growth and stomatal conductance significantly while lower doses (1.25-6.25 g dm -3 ) had a stimulative effect. Shoot K, Na, Fe and Ni increased and Ca, Mg, Mn, Zn and Cu decreased in this treatment. It was concluded that SS with low heavy metal content can be a potentially good fertilizer for high biomass non-food crops such as Szarvasi-1 energy grass. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Modeling thermomechanical pulp and paper activated sludge treatment plants to gain insight to the causes of bulking. (United States)

    Brault, Jean-Martin; Comeau, Yves; Perrier, Michel; Stuart, Paul


    The Activated Sludge Model No. 1 was chosen as the basis for model development and was modified to take into account the specific characteristics of pulp and paper effluents. The model was incorporated to the GPS-X simulation environment (Hydromantis, Hamilton, Ontario, Canada) to study operating deficiencies and nutrient transformations, particularly in relation to bulking. The results show that the process of ammonification is not significant at the studied mill and that the process of phosphatification (transformation of soluble organic phosphorus into orthophosphates) seems to be related to settling problems, as indicated by the sludge volume index. The phosphatification rate and the standard oxygen-transfer efficiency were found to decrease as the system entered a bulking state. Understanding the behavior of pulp and paper activated sludge can be improved by the incorporation of industry-specific processes and components to comprehensive models. These models then can be used to gain insight to the causes of bulking.

  17. Wastewater and sewage sludge application to willows and poplars grown in lysimeters-Plant response and treatment efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, I.; Aronsson, P. [Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Ecology building, P.O. Box 7043, SE 750 07 Uppsala (Sweden)


    Adding nutrient-rich residues such as municipal wastewater and sludge to willow and poplar short-rotation coppice gives more cost-effective and sustainable cultivation, but leaching to groundwater and disturbance to plant growth must be avoided. The effects of adding municipal wastewater irrigation to willows and poplars and sewage sludge to willows were compared in a two-year experiment. Wastewater irrigation enhanced plant growth. Near-zero nitrate-N concentrations occurred in drainage water when the root system of both species was well-established. The ability to retain N and P was satisfactory when poplars and willows were irrigated with wastewater. Thus relatively high additions of N and P with wastewater will probably not contaminate groundwater, but potential P leaching should not be underestimated. The same applies for sewage sludge applications to willow. (author)

  18. Ferrrate(VI) and freeze-thaw treatment for oxidation of hormones and inactivation of fecal coliforms in sludge. (United States)

    Diak, James; Örmeci, Banu


    This study examined the individual and combined effects of potassium ferrate(VI) additions and freeze-thaw conditioning for the treatment and dewatering of wastewater sludge in cold climates, with particular focus on the inactivation of fecal coliforms and oxidation of estrogens, androgens, and progestogens. The first phase of the study evaluated the effects of potassium ferrate(VI) pre-treatment followed by freeze-thaw at -20 °C using a low (0.5 g/L) and high (5.0 g/L) dose of potassium ferrate(VI). The results showed that pre-treatment of anaerobically digested sludge with 5 g/L of potassium ferrate(VI) reduced the concentration of fecal coliforms in the sludge cake to below 100 MPN/g DS. The second phase evaluated the ability of ferrate(VI) to oxidise selected hormones in sludge. Anaerobically digested sludge samples were spiked with 10 different hormones: estrone (E1), 17α-estradiol, 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2), equilin, mestranol, testosterone, norethindrone and norgestrel in two groups of low (3-75 ng/mL) and high (12-300 ng/L) concentration ranges of hormones. The samples were treated with either 0.5 or 1.0 g/L of potassium ferrate(VI), and hormone concentrations were measured again after treatment. Potassium ferrate(VI) additions as low as 1.0 g/L reduced the concentration of estrogens in sludge. Potassium ferrate(VI) additions of 0.5 and 1.0 g/L were less effective at reducing the concentrations of androgens and progestogens. Increasing ferrate(VI) dose would likely result in more substantial decreases in the concentrations of fecal coliforms and hormones. The results of this study indicate that the combined use of freeze-thaw and ferrate(VI) has the potential to provide a complete sludge treatment solution in cold regions.

  19. Microwave treatment of faecal sludge from intensively used toilets in the slums of Nairobi, Kenya. (United States)

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


    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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Availability of uranium present in the sludge generated at two stations of potable water treatment; Disponibilidad del uranio presente en el fango generado en dos estaciones de tratamiento de agua potable

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Serrano, A.; Baeza, A.; Salas, A.; Guillen, J.


    During the treatment is carried out in a Station Potable Water Treatment Plant sludge enriched are produced in components that have been removed from the water. The concentration and availability of radionuclides accumulated in a sludge during coagulation-flocculation will condition possible later use, so it is essential to carry out the characterization of sludge and its chemical speciation. (Author)

  1. Sludge from paper mill effluent treatment as raw material to produce carbon adsorbents: An alternative waste management strategy. (United States)

    Jaria, Guilaine; Silva, Carla Patrícia; Ferreira, Catarina I A; Otero, Marta; Calisto, Vânia


    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 m2 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Molecular characterization of activated sludge from a seawater‐processing wastewater treatment plant (United States)

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


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


    Directory of Open Access Journals (Sweden)

    Agnieszka Montusiewicz


    Full Text Available The study examined the effects of co-digestion of sewage sludge and mature landfill leachate at the volumetric ratio of 95:5% in primarily bioaugmented system. Bioaugmentation was carried out with the use of commercial product Arkea® in the volumetric dose of 5% and lasted three months prior to the co-digestion start-up. Co-digestion was undergone without bioaugmentation. The results indicated that in the first period (of three months following bioaugmentation, co-digestion led to biogas/methane yields only 5-8% lower as compared to anaerobic digestion of sewage sludge, and the differences were not statistically significant. Moreover, a comparable value of volatile solids removal was obtained. However, the effects became worse over time, i.e. a lower organics removal efficiency of 16% as well as 9.5–13% decreases of biogas/methane yields were achieved by applying co-digestion for a further period (of the same duration. Co-digestion of sewage sludge and mature landfill leachate could be recognized as quite efficient in the system that was primarily bioaugmented with the use of Arkea®. However, the beneficial impact of bioaugmentation remained for the limited period of three months after its completion. To sustain the favourable effects a periodical, repeatable bioaugmentation of the co-digestion system is required.

  4. Influence of enhanced biological phosphate removal on feedback of phosphorus from sludge treatment; Einfluss der erhoehten biologischen Phosphorelimination auf die Phosphorrueckbelastung aus der Schlammbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Jardin, N. [Inst. WAR, TH Darmstadt (Germany); Poepel, H.J. [Inst. WAR, TH Darmstadt (Germany)


    Phosphate release and phosphate fixation during sludge treatment of excess sludge was investigated with a pilot plant for enhanced biological phosphorus removal. The major part of the eliminated phosphorus in the pilot plant was due to the storage of polyphosphate in the excess sludge and was accompanied by an uptake of magnesium and potassium. Using separate thickening systems only a small P-feedback was observed, whereas with gravity thickeners a part of the polyphosphate was hydrolysed and phosphate was released into solution. Due to only a small transfer of the released phosphate from the sludge layer into the supernatant, the P-feedback was relatively low. As a result of a complete polyphosphate hydrolysis in stabilising systems, phosphate is released, but only a small part of the released phosphate remains in solution whereas the major fraction of the released phosphate was fixed by physico-chemical fixation mechanisms. (orig.) [Deutsch] Es wird ueber systematische Untersuchungen im halbtechnischen Massstab zum Einfluss der erhoehten biologischen Phosphorelimination auf die Phosphatrueckloesung und Phosphatrueckbelastung bei der Schlammbehandlung berichtet. Die durchgefuehrten Untersuchungen zeigten, dass der groesste Teil des im erhoehten Umfang gespeicherten Phosphors auf die Einlagerung von Polyphosphat zurueckzufuehren ist, wobei gleichzeitig auch Kalium- und Magnesiumionen aufgenommen werden. Die maschinellen Verfahren zur getrennten Ueberschussschlammeindickung verursachen nur eine geringe P-Rueckbelastung, waehrend bei der Schwerkrafteindickung das Polyphosphat teilweise hydrolysiert und als Phosphat rueckgeloest wird. Allerdings wurde nur ein geringer Transfer in den Ueberstand beobachtet, so dass die P-Rueckbelastung auch bei der Schwerkrafteindickung vergleichsweise gering war. Bei der Faulung und der aerob-thermophilen Stabilisierung wird das Polyphosphat vollstaendig hydrolisiert, aber nur ein kleiner Teil des freigesetzten Phosphats verbleibt in

  5. Basis for the development of sustainable optimisation indicators for activated sludge wastewater treatment plants in the Republic of Ireland. (United States)

    Gordon, G T; McCann, B P


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

  6. Evaluation of Municipal Wastewater Treatment Plant Activated Sludge for Biodegradation of Propylene Glycol as an Aircraft Deicing Fluid (United States)


    Seasonal variation of nitrifying community in trickling fliter-solids contact (TF/SC) activated sludge systems. Bioresource Technology , 2272-2279...sequencing batch reactors few with different organic carbon sources under varying solids reterntion times. Bioresource Technology . Ren, Y.-X., Nakano, K...INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED


    Directory of Open Access Journals (Sweden)

    S. Şahinkaya

    Full Text Available Abstract The effects of sonication, potassium ferrate (K2FeO4 oxidation and their simultaneous combination (called "sono-oxidative pre-treatment" on chemical properties and anaerobic digestion of waste activated sludge (WAS were investigated and compared comprehensively. Based on chemical parameters, the optimum operating conditions were found to be 0.3 g K2FeO4/g total solids (TS dosage for 2-h individual K2FeO4 oxidation, 0.50 W/mL ultrasonic power density for 10-min individual sonication and, lastly, the combination of 2.5-min sonication at 0.75 W/mL ultrasonic power density with 2-h chemical oxidation at 0.3 g K2FeO4/g TS dosage for sono-oxidative pre-treatment. The disintegration efficiencies of these methods under the optimized conditions were in the following descending order: 37.8% for sono-oxidative pre-treatment > 26.3% for sonication > 13.1% for K2FeO4 oxidation. The influences of these methods on anaerobic biodegradability were tested with the biochemical methane potential assay. It was seen that the cumulative methane production increased by 9.2% in the K2FeO4 oxidation reactor, 15.8% in the sonicated reactor and 18.6% in the reactor with sono-oxidative pre-treatment, compared to the control (untreated reactor.

  8. Treatment of Volatile Organic Compounds with Mesoporous Materials Prepared from Calcium Fluoride Sludge. (United States)

    Kang, Sv-Yuan; Tsai, Hsiao-Hsin; Nguyen, Nhat-Thien; Chang, Chang-Tang; Tseng, Chao-Heng


    Large amount of calcium fluoride sludge was generated by semiconductor industry every year. It also needs high requirement of fuel consumption using rotor concentrator and thermal oxidizer to treat VOCs. The mesoporous catalyst prepared by calcium fluoride sludge was used for VOCs treatment in this study. Acetone is a kind of solvent and used in a large number of laboratories and factories. The serious problems will be caused when it exposed to the environmental. Economic and practical technology is needed to eliminate this kind of hazardous air pollutant. In this research, the adsorption of acetone was tested with CF-MCM (mesoporous silica materials synthesized from calcium fluoride). The raw material was mixed with cationic cetyltrimethyl ammonium bromide (CTAB) surfactants, firstly. The prepared mesoporous silica materials were characterized by nitrogen adsorption and desorption analysis, transmission electron microscope (TEM), scanning electron microscopy (SEM), X-ray powder diffractometer (XRPD) and Fourier transform infrared spectroscopy (FTIR). The results showed that the surface area, large pore volume and pore diameter could be up to 862 m2 g(-1), 0.57 cm3 g(-1) and 2.9 nm, respectively. The crystal patterns of CF-MCM were similar with MCM-41 from TEM image. The adsorption capacity of acetone with CF-MCM was 118, 190, 194 and 201 mg g(-1), respectively, under 500, 1000, 1500 and 2000 ppm. Furthermore, the adsorption capacity of MCM-41 and CF-MCM was almost the same. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

  9. Proposal of a sequential treatment methodology for the safe reuse of oil sludge-contaminated soil. (United States)

    Mater, L; Sperb, R M; Madureira, L A S; Rosin, A P; Correa, A X R; Radetski, C M


    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.

  10. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Manhong, E-mail:; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li


    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge.

  11. Celebrating 40 years anaerobic sludge bed reactors for industrial wastewater treatment

    NARCIS (Netherlands)

    Van Lier, J.B.; Van der Zee, F.P.; Frijters, C.T.M.J.; Ersahin, M.E.


    In the last 40 years, anaerobic sludge bed reactor technology evolved from localized lab-scale trials to worldwide successful implementations at a variety of industries. High-rate sludge bed reactors are characterized by a very small foot print and high applicable volumetric loading rates. Best

  12. Sanitary Landfill. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook. (United States)

    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…

  13. Low-temperature thermal pre-treatment of municipal wastewater sludge: Process optimization and effects on solubilization and anaerobic degradation. (United States)

    Nazari, Laleh; Yuan, Zhongshun; Santoro, Domenico; Sarathy, Siva; Ho, Dang; Batstone, Damien; Xu, Chunbao Charles; Ray, Madhumita B


    The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood. Aiming to determine the impact of low temperature treatments on biogas production, the thermal pre-treatment process was first optimized based on an experimental design study on waste activated sludge in batch mode. The optimum temperature, reaction time and pH of the process were determined to be 80 °C, 5 h and pH 10, respectively. All three factors had a strong individual effect (p effect for temp. pH 2 (p = 0.002). Thermal pre-treatments, carried out on seven different municipal wastewater sludges at the above optimum operating conditions, produced increased COD solubilization of 18.3 ± 7.5% and VSS reduction of 27.7 ± 12.3% compared to the untreated sludges. The solubilization of proteins was significantly higher than carbohydrates. Methane produced in biochemical methane potential (BMP) tests, indicated initial higher rates (p = 0.0013) for the thermally treated samples (k hyd up to 5 times higher), although the ultimate methane yields were not significantly affected by the treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Off-Site Lime Stabilisation as an Option to Treat Pit Latrine Faecal Sludge for Emergency and Existing On-Site Sanitation Systems

    Directory of Open Access Journals (Sweden)

    Wilson Greya


    Full Text Available Off-site lime stabilisation for treating faecal sludge was assessed by undertaking small-scale (35 L and large-scale (600 L field trials in Blantyre, Malawi. Hydrated lime was dosed to maintain pH 10, pH 10.5, pH 11, pH 11.5, and pH 12 depending on the buffer capacity of the faecal sludge in the four replica small-scale field trials. Significant reduction of E. coli to below the detection limit of 104 CFU/100 mL within 1 hour of treatment was reported for pH > 11. Based on the small-scale findings, large-scale field trials were conducted and greater than 3 log removal of E. coli was observed under pH 12 conditions. Therefore, based on the study, off-site lime stabilisation by dosing lime in the range of 10–35% w/w (dry solid basis, depending on the buffer capacity and solids content of the sludge to maintain pH > 11, can be used to sanitise faecal sludge during emergencies, as well as for existing on-site sanitation systems.

  15. Effect of ultrasonic and ozone pre-treatments on pharmaceutical waste activated sludge's solubilisation, reduction, anaerobic biodegradability and acute biological toxicity. (United States)

    Pei, Jin; Yao, Hong; Wang, Hui; Shan, Dan; Jiang, Yichen; Ma, Lanqianya; Yu, Xiaohua


    Ultrasonic and ozone pre-treatment technologies were employed in this study to improve the anaerobic digestion efficiency of pharmaceutical waste activated sludge. The sludge solubilisation achieved 30.01% (150,000 kJ/kg TS) and 28.10% (0.1g O3/g TS) after ultrasonic treatment and ozone treatment. The anaerobic biodegradability after ultrasonic treatment was higher compared to ozonation due to the higher cumulative methane volume observed after 6 days (249 ml vs 190 ml). The ozonated sludge released the highest concentration of Cu(2+) into the liquid phase (6.640 mg L(-1)) compared to 0.530 mg/L for untreated sludge and 0.991 mg/L for sonicated sludge. The acute toxicity test measured by luminescent bacteria showed that anaerobic digestion could degrade toxic compounds and result in a reduction in toxicity. The main mechanism of action led to some differences in the treated sludge exhibiting higher potential for methane production from pharmaceutical waste sludge with ultrasonic treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Combined adsorption and degradation of the off-flavor compound 2-methylisoborneol in sludge derived from a recirculating aquaculture system. (United States)

    Azaria, Snir; Nir, Shlomo; van Rijn, Jaap


    Off-flavor in fish poses a serious threat for the aquaculture industry. In the present study, removal of 2-methylisoborneol (MIB), an off-flavor causing compound, was found to be mediated by adsorption and bacterial degradation in sludge derived from an aquaculture system. A numerical model was developed which augmented Langmuir equations of kinetics of adsorption/desorption of MIB with first order degradation kinetics. When laboratory-scale reactors, containing sludge from the aquaculture system, were operated in a recirculating mode, MIB in solution was depleted to undetectable levels within 6 days in reactors with untreated sludge, while its depletion was incomplete in reactors with sterilized sludge. When operated in an open flow mode, removal of MIB was significantly faster in reactors with untreated sludge. Efficient MIB removal was evident under various conditions, including ambient MIB levels, flow velocities and sludge loads. When operated in an open flow mode, the model successfully predicted steady MIB removal rates with time. During steady state conditions, most of the MIB removal was found to be due to microbial degradation of the adsorbed MIB. Findings obtained in this study can be used in the design of reactors for removal of off-flavor compounds from recirculating aquaculture systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Organochlorine pesticides removal from wastewater by pine bark adsorption after activated sludge treatment. (United States)

    Sousa, Sérgio; Jiménez-Guerrero, Pedro; Ruiz, Antonio; Ratola, Nuno; Alves, Arminda


    Pesticides have been responsible for strong environmental impacts, mainly due to their persistence in the environment. Removal technologies are usually combined, because degradation of organic matter is needed prior to a tertiary treatment to guarantee pesticides elimination to levels below legal limits (normally 0.1 microg L(-1)). Pine bark was studied as an alternative to activated carbon, for organochlorine pesticides removal. A combination of technologies based on biodegradation with activated sludge followed by pine bark adsorption treatment was used for lindane (LIN) and heptachlor (HEP) removal from contaminated waters. Pesticides were quantified throughout the process by GC-ECD preceded by solid-phase microextraction (SPME). An experimental set-up was maintained for 4 months, by feeding a standard solution with pesticides concentration of 1 microg L(-1) each and known organic matter (Chemical Oxygen Demand, COD, -563 mg O2 L(-1)) on a daily basis. COD suffered a reduction of about 81% in the biological step and no increase was detected in the subsequent adsorption treatment. Overall removal efficiency was 76.6% and above 77.7% for LIN and HEP, respectively.

  18. An integrated AMBBR and IFAS-SBR process for municipal wastewater treatment towards enhanced energy recovery, reduced energy consumption and sludge production. (United States)

    Gu, Jun; Xu, Guangjing; Liu, Yu


    The conventional activated sludge (CAS) process has been widely employed for wastewater treatment for more than one hundred years. Recently, more and more concerns have been raised on the CAS process due to its high energy consumption and production of huge amount of waste activated sludge, which are inevitably linked to the issue of environmental sustainability and global climate change. Facing to such emerging and challenging situation, this study reported a novel A-B process in which an anaerobic moving bed biofilm reactor (AMBBR) served a lead A-stage for COD capture towards biogas production and an integrated fixed-biofilm and activated sludge sequencing batch reactor (IFAS-SBR) was employed as B-stage for biological nitrogen removal. Results showed that about 85% of wastewater COD was removed in the steady-state AMBBR with a total energy production rate of 0.28 kWh/m3 wastewater treated, while 85% of N-removal was achieved when the stable nitrite shunt was established in the IFAS-SBR. Moreover, 90% of dissolved methane in the AMBBR effluent could be removed by the proposed flash chamber at the lower energy demand of 0.12 kWh/m3 which could be offset by the potential energy harvested from produced methane. Compared to the CAS process, the production of waste sludge was reduced by about 75% in the proposed A-B process due to the efficient COD capture at the A-stage, leading to significant energy savings from aeration for COD oxidation and post-treatment of waste sludge at the B-stage. Consequently, this study offers in-depth insights into A-B process which should be considered as an ideal candidate for achieving the energy-neutral or even energy positive operation of a municipal wastewater treatment. Given the complex situation in A-B process, future study is needed to look into the system optimization towards the operational synergy between A- and B-stage in terms of energy recovery and nitrogen removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. [Assessing environmental and economical benefits of integrated sewage treatment systems]. (United States)

    Li, Jin-rong; Zhang, Xiao-hong; Zhang, Hang-bin; Pan, Heng-yu; Liu, Qiang


    Sewage treatment, treated water treatment and sludge treatment are three basic units of an integrated sewage treatment system. This work assessed the influence of reusing or discharge of treated water and sludge landfill or compost on the sustainability of an integrated sewage treatment system using emergy analysis and newly proposed emergy indicators. This system's value included its environmental benefits and the products. Environmental benefits were the differences of the environmental service values before and after sewage treatment. Due to unavailability of data of the exchanged substance and energy in the internal system, products' values were attained by newly proposed substitution values. The results showed that the combination of sewage treatment, treated water reuse and sludge landfill had the strongest competitiveness, while the combination of sewage treatment, treated water reuse and earthworm compost was the most sustainable. Moreover, treated water reuse and earthworm compost were helpful for improving the sustainability of the integrated sewage treatment system. The quality of treated water and local conditions should be also considered when implementing the treated water reuse or discharge. The resources efficiency of earthworm compost unit needed to be further improved. Improved emergy indices were more suitable for integrated sewage treatment systems.

  20. Microbial Insight into a Pilot-Scale Enhanced Two-Stage High-Solid Anaerobic Digestion System Treating Waste Activated Sludge. (United States)

    Wu, Jing; Cao, Zhiping; Hu, Yuying; Wang, Xiaolu; Wang, Guangqi; Zuo, Jiane; Wang, Kaijun; Qian, Yi


    High solid anaerobic digestion (HSAD) is a rapidly developed anaerobic digestion technique for treating municipal sludge, and has been widely used in Europe and Asia. Recently, the enhanced HSAD process with thermal treatment showed its advantages in both methane production and VS reduction. However, the understanding of the microbial community is still poor. This study investigated microbial communities in a pilot enhanced two-stage HSAD system that degraded waste activated sludge at 9% solid content. The system employed process "thermal pre-treatment (TPT) at 70 °C, thermophilic anaerobic digestion (TAD), and mesophilic anaerobic digestion (MAD)". Hydrogenotrophic methanogens Methanothermobacter spp. dominated the system with relative abundance up to about 100% in both TAD and MAD. Syntrophic acetate oxidation (SAO) bacteria were discovered in TAD, and they converted acetate into H₂ and CO₂ to support hydrogenotrophic methanogenesis. The microbial composition and conversion route of this system are derived from the high solid content and protein content in raw sludge, as well as the operational conditions. This study could facilitate the understanding of the enhanced HSAD process, and is of academic and industrial importance.

  1. Microwaving human faecal sludge as a viable sanitation technology option for treatment and value recovery - A critical review. (United States)

    Afolabi, Oluwasola O D; Sohail, M


    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Delisting petition for 300-M saltstone (treated F006 sludge) from the 300-M liquid effluent treatment facility

    Energy Technology Data Exchange (ETDEWEB)


    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.

  3. Understanding the role of extracellular polymeric substances in an enhanced biological phosphorus removal granular sludge system. (United States)

    Wang, Randeng; Peng, Yongzhen; Cheng, Zhanli; Ren, Nanqi


    The role of extracellular polymeric substances (EPS) in the enhanced biological phosphorus removal (EBPR) process was investigated in a P-accumulating granular sludge system by analyzing the distribution and transfer of P, K(+), Mg(2+) and Ca(2+) in the sludge phase, EPS, and the bulk liquid. In the sludge phase, about 30% P, 44.7% K(+), 27.7% Mg(2+), 28% Ca(2+) accumulated in the EPS at the end of aeration. The rate of P, K(+), Mg(2+) and Ca(2+) released from the EPS matrix into the bulk liquid in the anaerobic phase was faster than the rate they were adsorbed from the bulk liquid into the EPS in the aerobic phase. P, K(+), Mg(2+) and Ca(2+) were retained in EPS before transferring into the phosphorus accumulating organisms (PAOs). These results suggest that EPS play a critical role in facilitating the accumulation and transfer of P, K(+), Ca(2+) and Mg(2+) between PAO cells and bulk liquid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Towards better environmental performance of wastewater sludge treatment using endpoint approach in LCA methodology

    Directory of Open Access Journals (Sweden)

    Isam Alyaseri


    Full Text Available 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

  5. Towards better environmental performance of wastewater sludge treatment using endpoint approach in LCA methodology. (United States)

    Alyaseri, Isam; Zhou, Jianpeng


    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

  6. Quantification of ammonia-oxidizing bacteria populations in full-scale sewage activated sludge systems and assessment of system variables affecting their performance. (United States)

    Limpiyakorn, T; Kurisu, F; Yagi, O


    This study carried out quantification of ammonia-oxidizing bacteria (AOB) populations in 12 full-scale sewage activated sludge systems that were different in ammonia removals and treatment processes during three different seasons. Experiment was divided into 3 parts: 1) analysis of AOB communities by PCR-DGGE-cloning-sequencing of 16S rRNA genes; 2) development of four real-time PCR primer sets for quantification of the particular AOB of interest; and 3) quantification of AOB populations by using the newly developed real-time PCR primer sets. The results suggested that all the primer sets gave good reproducibility and specificity for PCR amplification with the detection limits of 10(2) copies/PCR reaction. Although the 12 systems were different in several aspects, one of the identified sequence types of Nitrosomonas oligotropha cluster was the dominant AOB in every system and every season studied. However, the other sequence type of this cluster was not significantly involved in ammonia removals in the systems. The occurrence of N. communis cluster in the systems seemed to depend on the remaining oxygen concentrations in the sludge floc and thus the activity of aerobic heterotrophs in the aeration tanks. N. europaea-Nitrosococcus. mobilis solely existed in one A20 system of which the influent contained twice the chloride concentrations than those of other systems.

  7. Lodo de esgoto e sistema radicular da pupunheira Sewage sludge doses and the root system of peach palm

    Directory of Open Access Journals (Sweden)

    Fernando Vinicio Armas Vega


    Full Text Available Os efeitos do lodo de esgoto sobre o sistema radicular da pupunheira foram estudados em experimento em campo, em blocos casualizados, instalado em Ubatuba (SP, em julho 2001, na densidade de 5.000 plantas ha-1. As doses de lodo de esgoto fresco (79,7 % de umidade utilizadas foram de 0, 38, 76 e 152 t ha-1, equivalentes a 0, 100, 200 e 400 kg ha-1 de N. Os tratamentos foram aplicados no sulco de plantio, adicionando-se 15 g por planta de KCl como fonte de K. A análise do sistema radicular foi efetuada doze meses após, por meio de trado e de trincheiras e com o auxílio de fotos digitais. Detectou-se que o sistema radicular de pupunheiras com um ano de campo estava concentrado nas camadas superficiais (acima de 75 % nos primeiros 20 cm, assim como em distâncias de até 0,5 m da base da planta. O lodo de esgoto modificou positivamente a densidade do solo, alterando também favoravelmente a densidade das raízes. Houve aumento na biomassa radicular proporcional às doses de lodo de esgoto, existindo uma relação direta daquela com a fitomassa aérea. Doses de lodo equivalentes a 200 e 400 kg de N contribuíram para aprofundar o sistema radicular e proporcionaram maior quantidade relativa de raízes finas.The effects of sewage sludge doses on the root system of peach palm were studied in a field experiment, in randomized complete blocks, carried out in Ubatuba, state of São Paulo, Brazil. The trial was set up in July 2001, with a density of 5,000 plants ha-1. The sewage sludge doses (79.7 % water content were 0, 38, 76, and 152 t ha-1, which were equivalent to doses of 0, 100, 200, and 400 kg ha-1 of N. The treatments were applied in the planting furrow, and every plant was provided with K by a dose of 15 g potassium chloride. The root system was analyzed one year after planting using soil auger and digging of trenches and with the help of digital images. It was concluded that the root system of one-year old peach palm was concentrated in the

  8. Development of an ATP measurement method suitable for xenobiotic treatment activated sludge biomass. (United States)

    Nguyen, Lan Huong; Chong, Nyuk-Min


    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Study on Influence to Waste Water Treatment Plant’s Sludge by Low-carbon Catalytic Combustion Furnace of Natural Gas

    Directory of Open Access Journals (Sweden)

    Ren TianQi


    Full Text Available There are two parts in this experiment. One of is about the concentration of Variation of exhaust gas while heating sludge of waste water treatment plant. The other one is about introduce the problems of the traditional incineration processes of sludge of waste water treatment as compared between the sludge heated by natural gas catalytic combustion furnace and the tradition’s. We can see that natural gas low-carbon catalytic combustion furnace realize the near-zero emission of contaminates.

  10. [Improvement of municipal sewage sludge dewaterability by bioleaching: a pilot-scale study with a continuous plug flow reaction model]. (United States)

    Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng


    A plug-flow bio-reactor of 700 L working volume for sludge bioleaching was used in this study. The reactor was operationally divided into six sections along the direction of the sludge movement. Ten duration of continuous operation of sludge bioleaching with Acidibacillus spp. and 1.2 m3 x h(-1) aeration amount was conducted. In this system, sludge retention time was 2.5 d, and the added amount of microbial nutritional substance was 4 g x L(-1). During sludge bioleaching, the dynamic changes of pH, dewaterability (specific resistance to filtration, SRF) of sewage sludge in different sections, the moisture content and moisture evaporation rate of dewatered bioleached sludge cake obtained by chamber filter press were investigated. The results showed that the SRF of sludge significantly decreased from initial 1.50 x 10(13) m x kg(-1) to the final 0.34 x 10(13) m x kg(-1). The wasted bioleached sludge was collected and dewatered by chamber filter press under the following pressures as 0.3 MPa for 4 h (2 h for feeding sludge, 2 h for holding pressure), 3 h (1.5 h for feeding sludge, 1.5 h for holding pressure), 2 h (1 h for feeding sludge, 1 h for holding pressure), and 1 h (0.5 h for feeding sludge, 0.5 h for holding pressure). Correspondingly, the moisture of dewatered sludge was reduced to 57.9%, 59.2%, 59.6%, and 63.4% of initial moisture, respectively. Moreover, the moisture content of bioleached sludge cake was reduced to about 45% and less than 10% if the cake was placed at 25 degrees C for 15 h and 96 h, respectively. Obviously, sludge bioleaching followed by sludge dewatering using chamber filter press is a promising attractive approach for sludge half-dryness treatment in engineering application.

  11. Production of polyhydroxyalkanoates (PHA) using sludge from different wastewater treatment processes and the potential for medical and pharmaceutical applications. (United States)

    Lam, Wai; Wang, Yujie; Chan, Pui Ling; Chan, Shun Wan; Tsang, Yiu Fai; Chua, Hong; Yu, Peter Hoi Fu


    In this study, seven strains of bacteria with polyhydroxyalkanoates (PHA)-producing ability (i.e. Bacillus cereus, Pseudomonas putida, Bacillus pumilus, Pseudomona huttiensis, Yersinia frederiksenii, Aeromonas ichthiosmia, and Sphingopyxis terrae) were isolated from various waste treatment plants in Hong Kong. Simultaneous wastewater treatment and PHA accumulation were successfully achieved in the bioreactors using isolated bacteria from different sludges. At the organic loading less than 13,000 ppm, more than 95% of chemical oxygen demand (COD) was removed by the isolated strains before the decrease of PHA accumulation. In addition, more than 95% of nitrogen removal was achieved by all isolated strains. In the bioreactors inoculated with single strains, the highest yields of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyvalerate) (PHV) were obtained in A. ichthiosmia (84 mg PHB/g) and B. cereus (69 mg/g), respectively. For the mixed culture, the highest yields of PHB and PHV were increased by 55% and 45% in the system inoculated with B. pumilus and A. ichthiosmia. The biologically synthesized PHA also showed the potential applications in drug delivery and tissue engineering. PHA-nanoparticles loaded with pyrene were successfully prepared by recombinant Escherichia coli. The results of in vitro drug release and biocompatibility tests revealed that nanoparticles could be used as safer dray carriers with high loading capacity and efficiency. After 20 days, the cells successfully grew on 90% of the PHA-aortic valve.

  12. Estimation of the electric power potential using wastewater sludge produced from the Percy Steward Wastewater Treatment Works (PS-WWTW) in Mogale City local municipality

    CSIR Research Space (South Africa)

    Mema, V


    Full Text Available Energy recovered from biogas in the form of methane can reduce the usage of electricity generated from fossil fuels thereby lessening greenhouse gas deposits into environment. Sewage sludge produced by Municipal Wastewater Treatment Works composes...

  13. Effects of treatment time and temperature on the DC corona pretreatment performance of waste activated sludge (United States)

    Yu, GAO; Ning, ZHAO; Yongdi, DENG; Minghang, WANG; Boxue, DU


    In order to improve the anaerobic digestion efficiency of waste activated sludge (WAS), a pretreatment procedure should be carried out so as to disrupt the microbial cell structure, thus releasing intracellular organic matters. In this paper, a corona discharge triggered by a DC voltage was employed to pre-treat WAS for various time periods under different temperatures. The magnitude of the DC voltage was 4 kV at both negative and positive polarities. The changes in the soluble chemical oxygen demand, phosphorus and nitrogen content, and pH value within the WAS were utilized to estimate the pretreatment performance of the DC corona. It was found that with increasing treatment time, the pretreatment efficiency tends to be reduced. With increased temperature, the pretreatment efficiency appears to be better. It is suggested that the oxidative species and the active particles generated in the corona discharge play an important role in disrupting the microbial cell structure, which is dependent upon the treatment time and the temperature.

  14. Advanced phosphorus recovery using a novel SBR system with granular sludge in simultaneous nitrification, denitrification and phosphorus removal process. (United States)

    Lu, Yong-Ze; Wang, Hou-Feng; Kotsopoulos, Thomas A; Zeng, Raymond J


    In this study, a novel process for phosphorus (P) recovery without excess sludge production from granular sludge in simultaneous nitrification-denitrification and P removal (SNDPR) system is presented. Aerobic microbial granules were successfully cultivated in an alternating aerobic-anaerobic sequencing batch reactor (SBR) for removing P and nitrogen (N). Dense and stable granular sludge was created, and the SBR system showed good performance in terms of P and N removal. The removal efficiency was approximately 65.22 % for N, and P was completely removed under stable operating conditions. Afterward, new operating conditions were applied in order to enhance P recovering without excess sludge production. The initial SBR system was equipped with a batch reactor and a non-woven cloth filter, and 1.37 g of CH3COONa·3H2O was added to the batch reactor after mixing it with 1 L of sludge derived from the SBR reactor to enhance P release in the liquid fraction, this comprises the new system configuration. Under the new operating conditions, 93.19 % of the P contained in wastewater was released in the liquid fraction as concentrated orthophosphate from part of granular sludge. This amount of P could be efficiently recovered in the form of struvite. Meanwhile, a deterioration of the denitrification efficiency was observed and the granules were disintegrated into smaller particles. The biomass concentration in the system increased firstly and then maintained at 4.0 ± 0.15 gVSS/L afterward. These results indicate that this P recovery operating (PRO) mode is a promising method to recover P in a SNDPR system with granular sludge. In addition, new insights into the granule transformation when confronted with high chemical oxygen demand (COD) load were provided.

  15. Scientific basis of dissolved organic carbon limitation for landfilling of municipal treatment sludge--is it attainable and justifiable? (United States)

    Sözen, S; Cokgor, E Ubay; Insel, G; Tas, D Okutman; Dulkadiroglu, H; Karaca, C; Filibeli, A; Meric, S; Orhon, D


    This study evaluated the scientific and technical basis of the dissolved organic carbon (DOC) limitation imposed on municipal sludge for landfilling, mainly for assessing the attainability of the implemented numerical level. For this purpose, related conceptual framework was analyzed, covering related sewage characteristics, soluble microbial products generation, and substrate solubilization and leakage due to hydrolysis. Soluble COD footprint was experimentally established for a selected treatment plant, including all the key steps in the sequence of wastewater treatment and sludge handling. Observed results were compared with reported DOCs in other treatment configurations. None of the leakage tests performed or considered in the study could even come close to the prescribed limitation. All observed results reflected 10-20 fold higher DOC levels than the numerical limit of 800 mg/kg (80 mg/L), providing conclusive evidence that the DOC limitation imposed on municipal treatment sludge for landfilling is not attainable, and therefore not justifiable on the basis of currently available technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters. (United States)

    Kato, M T; Field, J A; Versteeg, P; Lettinga, G


    The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was investigated in laboratory-scale reactors at 30oC. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to12 g COD/L . d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGBS reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A. more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L. d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up, the operation should be limited to an organic loading rate of 7 g COD/L d. and to a liquid up-flow velocity between 2.5 and 5.5 m/h (c) 1994 John Wiley & Sons, Inc.

  17. Mixing studies in an Orbal activated sludge system

    African Journals Online (AJOL)



    Jan 1, 2001 ... of the plants operated by North West Water Ltd., UK and discusses the implications of the data for future studies. Materials and methods. The Orbal treatment .... dispersed during its passage through the upstream channels, such a tightly defined pulse was unavailable. The method developed by Martin and ...

  18. A review of modeling approaches in activated sludge systems ...

    African Journals Online (AJOL)

    The feasibility of using models to understand processes, predict and/or simulate, control, monitor and optimize WasteWater Treatment Plants (WWTPs) has been explored by a number of researchers. Mathematical modeling provides a powerful tool for design, operational assistance, forecast future behavior and control.

  19. Sludge accumulation and distribution impact the hydraulic performance in waste stabilisation ponds. (United States)

    Coggins, Liah X; Ghisalberti, Marco; Ghadouani, Anas


    Waste stabilisation ponds (WSPs) are used worldwide for wastewater treatment, and throughout their operation require periodic sludge surveys. Sludge accumulation in WSPs can impact performance by reducing the effective volume of the pond, and altering the pond hydraulics and wastewater treatment efficiency. Traditionally, sludge heights, and thus sludge volume, have been measured using low-resolution and labour intensive methods such as 'sludge judge' and the 'white towel test'. A sonar device, a readily available technology, fitted to a remotely operated vehicle (ROV) was shown to improve the spatial resolution and accuracy of sludge height measurements, as well as reduce labour and safety requirements. Coupled with a dedicated software package, the profiling of several WSPs has shown that the ROV with autonomous sonar device is capable of providing sludge bathymetry with greatly increased spatial resolution in a greatly reduced profiling time, leading to a better understanding of the role played by sludge accumulation in hydraulic performance of WSPs. The high-resolution bathymetry collected was used to support a much more detailed hydrodynamic assessment of systems with low, medium and high accumulations of sludge. The results of the modelling show that hydraulic performance is not only influenced by the sludge accumulation, but also that the spatial distribution of sludge plays a critical role in reducing the treatment capacity of these systems. In a range of ponds modelled, the reduction in residence time ranged from 33% in a pond with a uniform sludge distribution to a reduction of up to 60% in a pond with highly channelized flow. The combination of high-resolution measurement of sludge accumulation and hydrodynamic modelling will help in the development of frameworks for wastewater sludge management, including the development of more reliable computer models, and could potentially have wider application in the monitoring of other small to medium water bodies

  20. K Basin spent fuel sludge treatment alternatives study. Volume 2, Technical options

    Energy Technology Data Exchange (ETDEWEB)

    Beary, M.M.; Honekemp, J.R.; Winters, N. [Science Applications International Corp., Richland, WA (United States)


    Approximately 2100 metric tons of irradiated N Reactor fuel are stored in the KE and KW Basins at the Hanford Site, Richland, Washington. Corrosion of the fuel has led to the formation of sludges, both within the storage canisters and on the basin floors. Concern about the degraded condition of the fuel and the potential for leakage from the basins in proximity to the Columbia River has resulted in DOE`s commitment in the Tri-Party Agreement (TPA) to Milestone M-34-00-T08 to remove the fuel and sludges by a December 2002 target date. To support the planning for this expedited removal action, the implications of sludge management under various scenarios are examined. This report, Volume 2 of two volumes, describes the technical options for managing the sludges, including schedule and cost impacts, and assesses strategies for establishing a preferred path.

  1. Peculiarities of a Glass-Sludge Mixture Subjected to Low-Temperature Treatment

    National Research Council Canada - National Science Library

    Abigail Parra Parra; Marina Vlasova; Pedro Antonio Márquez Aguilar; Tamara Tomila


    In this work, the specific features offormation of a composite material consisting of a mixture of low-melting ground glass and waste active sludge, which is used for sewage purification, have been considered...

  2. Petroleum sludge treatment and reuse for cement production as setting retarder (United States)

    Aeslina, A. K.; Ali, B.


    Petroleum sludge is a dangerous waste that needs to be treated to avoid any contamination of soil and groundwater due to its disposal. As an attempt to treat this waste, it has been incorporated into cement production as substitution for gypsum. As results, 5% of petroleum sludge has shown effective results and could play the same role of gypsum in delaying the flash setting of cement clinker.

  3. Potentials and limits of anaerobic digestion of sewage sludge: energy self-sufficient municipal wastewater treatment plant? (United States)

    Jenicek, P; Bartacek, J; Kutil, J; Zabranska, J; Dohanyos, M


    Anaerobic digestion is the only energy-positive technology widely used in wastewater treatment. Full-scale data prove that the anaerobic digestion of sewage sludge can produce biogas that covers a substantial amount of the energy consumption of a wastewater treatment plant (WWTP). In this paper, we discuss possibilities for improving the digestion efficiency and biogas production from sewage sludge. Typical specific energy consumptions of municipal WWTPs per population equivalent are compared with the potential specific production of biogas to find the required/optimal digestion efficiency. Examples of technological measures to achieve such efficiency are presented. Our findings show that even a municipal WWTP with secondary biological treatment located in a moderate climate can come close to energy self-sufficiency. However, they also show that such self-sufficiency is dependent on: (i) the strict optimization of the total energy consumption of the plant, and (ii) an increase in the specific biogas production from sewage sludge to values around 600 L per kg of supplied volatile solids.

  4. Energy saving system with high effluent quality for municipal sewage treatment by UASB-DHS. (United States)

    Tanaka, H; Takahashi, M; Yoneyama, Y; Syutsubo, K; Kato, K; Nagano, A; Yamaguchi, T; Harada, H


    An up-flow anaerobic sludge blanket (UASB) - down-flow hanging sponge (DHS) was applied to Japanese municipal sewage treatment, and its treatability, energy consumption, and sludge production were evaluated. The designed sewage load was 50 m(3)/d. The sewage typically had a chemical oxygen demand (COD) of 402 mg/L, a suspended solids (SS) content of 167 mg/L, and a temperature of 17-29 °C. The UASB and DHS exhibited theoretical hydraulic retention times of 9.7 and 2.5 h, respectively. The entire system was operated without temperature control. Operation was started with mesophilic anaerobic digested sludge for the UASB and various sponge media for the DHS. Continuous operational data suggest that although the cellulose decomposition and methanogenic process in the UASB are temperature sensitive, stable operation can be obtained by maintaining a satisfactory sludge volume index and sludge concentration. For the DHS, the cube-type medium G3-2 offers superior filling rates, biological preservation and operational execution. The SS derived from the DHS contaminated the effluent but could be removed by optional sand filtration. A comparison with conventional activated sludge (CAS) treatment confirmed that this system is adequate for municipal sewage treatment, with an estimated energy requirement and excess sludge production approximately 75 and 85% less than those of CAS, respectively.

  5. Stabilization of heavy metals in municipal sewage sludge by freeze-thaw treatment with a blend of diatomite, FeSO4, and Ca(OH)2. (United States)

    Wang, Jing; Fu, Rongbing; Xu, Zhen


    In this work, the effects of diatomite with 15% FeSO4•7H2O and 7.5% Ca(OH)2 on sludge stabilization were investigated using batch leaching tests. The influence of cell rupture caused by freezing and thawing on stabilization was also evaluated. The results indicated that the optimal diatomite percentage was 2%. Cell rupture by freezing and thawing reduced heavy metal leachability, followed by cell death and decrease of organic groups. The concentration of heavy metals in sludge leachate increased after cell rupture, indicating that the heavy metal leachability was reduced after freezing and thawings. Moreover, the stabilization effects were generally improved after freezing and thawing. As compared with the stabilization of the original sludge, the unstable fractions decreased and the residual fractions of the heavy metals increased in the stabilized sludge after cell rupture. This study developed a method to stabilize heavy metals in municipal sewage sludge. Diatomite combined with FeSO4·7H2O and Ca(OH)2 improved the treatment of sewage sludge contaminated by heavy metals. Cell lysis by freeze-thaw treatment reduced the risk of leaching heavy metals caused by cell death and decreased major organic groups in the sludge.

  6. A comparative study of clonal selection algorithm for effluent removal forecasting in septic sludge treatment plant. (United States)

    Chun, Ting Sie; Malek, M A; Ismail, Amelia Ritahani


    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.

  7. Treatment of Direct Blending Dye Wastewater and Recycling of Dye Sludge

    Directory of Open Access Journals (Sweden)

    Ming-Li Li


    Full Text Available 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.

  8. Prediction analysis of effluent removal in a septic sludge treatment plant: a biomimetics engineering approach. (United States)

    Chun, Ting Sie; Malek, M A; Ismail, Amelia Ritahani


    Effluent discharge from septic tanks is affecting the environment in developing countries. The most challenging issue facing these countries is the cost of inadequate sanitation, which includes significant economic, social, and environmental burdens. Although most sanitation facilities are evaluated based on their immediate costs and benefits, their long-term performance should also be investigated. In this study, effluent quality-namely, the biological oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solid (TSS)-was assessed using a biomimetics engineering approach. A novel immune network algorithm (INA) approach was applied to a septic sludge treatment plant (SSTP) for effluent-removal predictive modelling. The Matang SSTP in the city of Kuching, Sarawak, on the island of Borneo, was selected as a case study. Monthly effluent discharges from 2007 to 2011 were used for training, validating, and testing purposes using MATLAB 7.10. The results showed that the BOD effluent-discharge prediction was less than 50% of the specified standard after the 97(th) month of operation. The COD and TSS effluent removals were simulated at the 85(th) and the 121(st) months, respectively. The study proved that the proposed INA-based SSTP model could be used to achieve an effective SSTP assessment and management technique.

  9. Analysis and modelling of predation on biofilm activated sludge process: Influence on microbial distribution, sludge production and nutrient dosage. (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R


    The influence of predation on the biofilm activated sludge (BAS) process is studied using a unified model that incorporates hydrolysis and predation phenomena into the two stages of the BAS system: moving bed biofilm reactor pre-treatment (bacterial-predator stage) and activated sludge (predator stage). The unified model adequately describes the experimental results obtained in a cellulose and viscose full-scale wastewater plant and has been used to evaluate the role and contribution of predator microorganisms towards removal of COD, nutrient requirements, sludge production and microbial distribution. The results indicate that predation is the main factor responsible for the reduction of both nutrient requirements and sludge production. Furthermore, increasing the sludge retention time (SRT) does not influence the total biomass content in the AS reactor of a BAS process in two different industrial wastewater treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. A swirling jet-induced cavitation to increase activated sludge solubilisation and aerobic sludge biodegradability. (United States)

    Mancuso, Giuseppe; Langone, Michela; Andreottola, Gianni


    In this work, a modified swirling jet induced hydrodynamic cavitation (HC) has been used for the pre-treatment of excess sludge. In order to both improve the HC treatment efficiencies and reduce the energy consumption, the effectiveness of the HC reactor on sludge disintegration and on aerobic biodegradability has been investigated at different operating conditions and parameters, such as temperature, inlet pressure, sludge total solid (TS) content and reactor geometry. The inlet pressure was related to the flow velocity and pressure drop. The best results in terms of sludge solubilisation were achieved after 2h of HC treatment, treating a 50.0gTSL -1 and using the three heads Ecowirl system, at 35.0°C and 4.0bar. Chemical and respirometric tests proved that sludge solubilisation and aerobic biodegradability can be efficiently enhanced through HC pre-treatment technique. At the optimum operating conditions, the specific supplied energy has been varied from 3276 to 12,780kJkgTS -1 in the HC treatment, by increasing the treatment time from 2 to 8 h, respectively. Low endogenous decay rates (b H ) were measured on the excess sludge at low specific supplied energy, revealing that only an alteration in floc structure was responsible for the sludge solubilisation. On the contrary, higher b H values were measured at higher specific supplied energy, indicating that the sludge solubilisation was related to a decreasing biomass viability, as consequence of dead cells and/or disrupted cells (cell lysis). Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Hydrothermal Liquefaction and Upgrading of Municipal Wastewater Treatment Plant Sludge: A Preliminary Techno-Economic Analysis, Rev.1

    Energy Technology Data Exchange (ETDEWEB)

    Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhu, Yunhua [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Susanne B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elliott, Douglas C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schmidt, Andrew J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hallen, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billing, Justin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Todd R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fox, Samuel P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maupin, Gary D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    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

  12. Pilot tests of microbe-soil combined treatment of waste drilling sludge

    Directory of Open Access Journals (Sweden)

    Lirong Chen


    Full Text Available Microbe-soil combined treatment is a newly developed technology in view of the defects of the curing process and waste drilling mud slag properties. In particular, 0.3%–0.5% bioremediation reagents were fully mixed with the waste drilling sludge according to its wet and dry degree, and 1.5 folds to twice weight of more finely ground soil was added in the mix, which was covered by soil of 5–15 cm thick and thereby grasses or greeneries were planted on the soil. The process was successfully applied to some fields of Well Danqian 001-8, Well Lianhua 000-X8, etc. After three months of such treatment, the main indexes of the drilling solid waste such as the degradation of COD and the oil-degrading ratio reached more than 90%, the index of leaching solution met the requirement of the first grade in the national “Integrated Wastewater Discharge Standard”; heavy metal ion concentration in soil did not change significantly with the indicators meeting the requirement of the third grade in the national “Soil Environmental Quality Standard” (Dry Land; and no harmful effects of heavy metals have ever been found on the planted grasses and greeneries. In conclusion, with this microbe-soil technology, the soil property will recover its background values without any other chemical additives, realizing the ecological restoration and reuse of land covered by wellsite wastes, so it is in line with the energy-saving and environmentally-friendly treatment way.

  13. Methane enhancement through oxidative cleavage and alkali solubilization pre-treatments for corn stover with anaerobic activated sludge. (United States)

    Hassan, Muhammad; Ding, Weimin; Bi, Jinhua; Mehryar, Esmaeil; Talha, Zahir Ahmed Ali; Huang, Hongying


    In the present study, thermo-chemical pre-treatment was adopted to evaluate methane production potential from corn stover by co-digesting it with anaerobic activated sludge. Three chemicals H2O2, Ca(OH)2 and NaOH were selected with two levels of concentration. All thermo-chemical pre-treatments were found significant (PProcess biochemistry during the anaerobic digestion process was taken into consideration to optimize the most feasible thermo-chemical pre-treatment for corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Enhanced biological phosphorus removal from activated sludge system; Eliminacion biologica del fosfor en aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Pidre Bocardo, J. R.; Toja Santillana, J.; Alonso Alvarez, E. [Sevilla (Spain)


    A literature review of enhanced biological phosphorus removal was performed. This biological removal is based on the selective enrichment of bacteria accumulating inorganic polyphosphate, obtained at a cyclic regime of alternating anaerobic and aerobic conditions; or anaerobic, anoxic and aerobic zones for combined nitrogen and phosphorus removal. Some bacterial groups may to be implicate in this process, the gen Acinetobacter has been the most studied. In this paper a study of phosphorate forms from wastewater for a conventional activated sludge system is presented. (Author) 40 refs.

  15. Dynamics of microbiological parameters, enzymatic activities and worm biomass production during vermicomposting of effluent treatment plant sludge of bakery industry. (United States)

    Yadav, Anoop; Suthar, S; Garg, V K


    This paper reports the changes in microbial parameters and enzymatic activities during vermicomposting of effluent treatment plant sludge (ETPS) of bakery industry spiked with cow dung (CD) by Eisenia fetida. Six vermibins containing different ratios of ETPS and CD were maintained under controlled laboratory conditions for 15 weeks. Total bacterial and total fungal count increased upto 7th week and declined afterward in all the bins. Maximum bacterial and fungal count was 31.6 CFU × 10(6) g(-1) and 31 CFU × 10(4) g(-1) in 7th week. Maximum dehydrogenase activity was 1921 μg TPF g(-1) h(-1) in 9th week in 100 % CD containing vermibin, whereas maximum urease activity was 1208 μg NH4 (-)N g(-1) h(-1) in 3rd week in 100 % CD containing vermibin. The enzyme activity and microbial counts were lesser in ETPS containing vermibins than control (100 % CD). The growth and fecundity of the worms in different vermibins were also investigated. The results showed that initially biomass and fecundity of the worms increased but decreased at the later stages due to non-availability of the palatable feed. This showed that quality and palatability of food directly affect biological parameters of the system.

  16. Effects of electrokinetic treatment of contaminated sludge on migration and transformation of Cd, Ni and Zn in various bonding states. (United States)

    Gao, Jie; Luo, Qi-Shi; Zhu, Jiang; Zhang, Chang-Bo; Li, Bing-Zhi


    This study assesses the effect of electrokinetic processes on the migration and bonding states of various heavy metals in municipal sludge. The transformation and migration are discussed through the examination of sludge characteristics and distribution of Cd, Zn and Ni after electrokinetic treatments. The migration and distribution of the contaminants after the electrokinetic treatments were determined for each sludge sample by sequential extraction. The noticeable changes on the average speciation fractions of Cd, Zn and Ni were observed that oxidizable heavy metals increased and reducible fraction decreased due to the application of voltage. Bivariate correlation analysis indicated that the amounts of different bonding states of Zn and Ni were significantly correlated (Pelectrokinetic processes, indicating the existing of mutual transformation between different speciation fractions over time. The analysis also indicated that the exchangeable Cd showed a close negative relationship with reducible Cd (P<0.01), whereas the reducible Cd was negatively related to residual Cd (P<0.05). Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Semi-aerobic fermentation as a novel pre-treatment to obtain VFA and increase methane yield from primary sludge. (United States)

    Peces, M; Astals, S; Clarke, W P; Jensen, P D


    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. Copyright © 2015 Elsevier Ltd. All rights reserved.


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    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