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Sample records for activated sludge wastewater

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

    Science.gov (United States)

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

    2014-05-01

    Textile effluents are characterised by high content of recalcitrant compounds and are often discharged (together with municipal wastewater to increase their treatability) into centralized wastewater treatment plants with a complex treatment scheme. This paper reports the results achieved adopting a granular sludge system (sequencing batch biofilter granular reactor - SBBGR) to treat mixed municipal-textile wastewater. Thanks to high average removals in SBBGR (82.1% chemical oxygen demand, 94.7% total suspended solids, 87.5% total Kjeldahl nitrogen, 77.1% surfactants), the Italian limits for discharge into a water receiver can be complied with the biological stage alone. The comparison with the performance of the centralized plant treating the same wastewater has showed that SBBGR system is able to produce an effluent of comparable quality with a simpler treatment scheme, a much lower hydraulic residence time (11 h against 30 h) and a lower sludge production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effect of activated sludge culture conditions on Waxberry wastewater

    Science.gov (United States)

    Shi, Liang; He, Lingfeng; Zhang, Yongli

    2018-03-01

    Treated activated sludge is suitable for the treatment of wastewater. Biochemical method is used to treat the wastewater, and the influence of time on the COD index is investigated. The results showed that time had a significant effect on COD, and then affected the performance of activated sludge. Under different time, according to the order of time from short to long, COD decreases in turn. Under the action of activated sludge, the degradation of myrica rubra wastewater samples, after 25 h aeration for 96 h, the effect is better. Under this condition, the COD value was reduced at 72 mg/L, and the COD removal efficiency of myrica rubra wastewater was up to 93.39 %, and reached the two level discharge standard of municipal wastewater treatment.

  3. Nitrogen removal from urban wastewater by activated sludge ...

    African Journals Online (AJOL)

    This study deals with nitrogen removal from urban wastewater employing the activated sludge process at low temperature. It aims at determining the performances and rates of nitrification, and characterising the autotrophic biomass (concentration and kinetic parameters) at 11°C and for F/M ratios higher than the ...

  4. Wastewater treatment in a hybrid activated sludge baffled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tizghadam, Mostafa [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France); Dagot, Christophe [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France)], E-mail: dagot@ensil.unilim.fr; Baudu, Michel [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France)

    2008-06-15

    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 3 h HRT, and in the organic loading rate (OLR) of 5.36 kg COD m{sup -3} day{sup -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.

  5. Characterization of Wastewater for Modelling of Activated Sludge Processes

    DEFF Research Database (Denmark)

    Henze, Mogens

    1992-01-01

    The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolyzable, slowly hydrolyzable, biomass and inert suspended material. Methods for measuring are also discussed....... Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found...

  6. Nitrate control strategies in an activated sludge wastewater treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenhao; Tao, Erpan; Chen, Xiaoquan; Liu, Dawei [South China University of Technology, Guangzhou (China); Liu, Hongbin [Kyung Hee University, Yongin (Korea, Republic of)

    2014-03-15

    We studied nitrate control strategies in an activated sludge wastewater treatment process (WWTP) based on the activated sludge model. Two control strategies, back propagation for proportional-integral-derivative (BP-PID) and adaptive-network based fuzzy inference systems (ANFIS), are applied in the WWTP. The simulation results show that the simple local constant setpoint control has poor control effects on the nitrate concentration control. However, the ANFIS (4*1) controller, which considers not only the local constant setpoint control of the nitrate concentration, but also three important indices in the effluent--ammonia concentration, total suspended sludge concentration and total nitrogen concentration--demonstrates good control performance. The results also prove that ANFIS (4*1) controller has better control performance than that of the controllers PI, BP-PID and ANFIS (2*1), and that the ANFIS (4*1) controller is effective in improving the effluent quality and maintaining the stability of the effluent quality.

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

    Science.gov (United States)

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

    2017-01-01

    We investigated anammox with a focus on biofilm in 10 wastewater treatment plants (WWTPs) that use activated sludge treatment of swine wastewater. In three plants, we found red biofilms in aeration tanks or final sedimentation tanks. The biofilm had higher anammox 16S rRNA gene copy numbers (up to 1.35 × 10 12 copies/g-VSS) and higher anammox activity (up to 295 μmoL/g-ignition loss/h) than suspended solids in the same tank. Pyrosequencing analysis revealed that Planctomycetes accounted for up to 17.7% of total reads in the biofilm. Most of them were related to Candidatus Brocadia or Ca. Jettenia. The highest copy number and the highest proportion of Planctomycetes were comparable to those of enriched anammox sludge. Thus, swine WWTPs that use activated sludge treatment can fortuitously acquire anammox biofilm. Thus, concentrated anammox can be detected by focusing on red biofilm. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Wastewater treatment in a hybrid activated sludge baffled reactor

    International Nuclear Information System (INIS)

    Tizghadam, Mostafa; Dagot, Christophe; Baudu, Michel

    2008-01-01

    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 3 h HRT, and in the organic loading rate (OLR) of 5.36 kg COD 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

  9. Toxicity formation and distribution in activated sludge during treatment of N,N-dimethylformamide (DMF) wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Na; Chen, Xiurong, E-mail: xrchen@ecust.edu.cn; Lin, Fengkai; Ding, Yi; Zhao, Jianguo; Chen, Shanjia

    2014-01-15

    Highlights: • We studied mechanism of sludge organic toxicity formation in wastewater treatment. • The organic toxicity distributed mainly in the inner section of sludge flocs. • The organic toxicity of sludge increased with DMF initial concentrations increments. • The property of bacteria community correlates significantly with sludge toxicity. -- Abstract: The organic toxicity of sludge in land applications is a critical issue; however, minimal attention has been given to the mechanism of toxicity formation during high-strength wastewater treatment. To investigate the relevant factors that contribute to sludge toxicity, synthetic wastewater with N,N-dimethylformamide (DMF) was treated in a sequential aerobic activated sludge reactor. The acute toxicity of sludge, which is characterised by the inhibition rate of luminous bacteria T3, is the focus of this study. Using an operational time of 28 days and a hydraulic retention time of 12 h, the study demonstrated a positive relationship between the acute toxicity of sludge and the influent DMF concentration; the toxicity centralised in the intracellular and inner sections of extracellular polymeric substances (EPS) in sludge flocs. Due to increased concentrations of DMF, which ranged from 40 to 200 mg L{sup −1}, the sludge toxicity increased from 25 to 45%. The organic toxicity in sludge flocs was primarily contributed by the biodegradation of DMF rather than adsorption of DMF. Additional investigation revealed a significant correlation between the properties of the bacterial community and sludge toxicity.

  10. 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

    2015-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    Alexandre V.M.F.

    2016-03-01

    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.

  12. Management experience on microthrix parvicella bulking in an activated sludge wastewater treatment plant

    International Nuclear Information System (INIS)

    De Bortoli, N.; Mion, M.; Di Giorgio, G.; Goi, D.

    2005-01-01

    Activated sludge wastewater treatment processes may give inefficiencies due to biological imbalances involving biomass. In fact, external causes as temperature lowering can increase the proliferation of the filamentous bacterium Microthrix parvicella into activated sludge flocks. Microthrix parvicella increases may create dangerous bulking phenomena compromising secondary settling without varying bio-kinetic parameters. In this case of study, a method to defeat growth of Microthrix parvicella has been set up. Aluminium poly-chloride (PAC) has been added to activated sludge contained into oxidation tanks of a municipal wastewater treatment plant, where a large growth of Microthrix parvicella has been periodically observed. It has been demonstrated that a definite PAC concentration can reduce Microthrix parvicella proliferation into activated sludge flocks so bulking phenomena can be well reduced [it

  13. [Harvest of the carbon source in wastewater by the adsorption and desorption of activated sludge].

    Science.gov (United States)

    Liu, Hong-Bo; Wen, Xiang-Hua; Zhao, Fang; Mei, Yi-Jun

    2011-04-01

    The carbon source in municipal wastewater was adsorbed by activated sludge and then harvested through the hydrolysis of activated sludge. Results indicated that activated sludge had high absorbing ability towards organic carbon and phosphorus under continuous operation mode, and the average COD and TP absorption rate reached as high as 63% and 76%, respectively. Moreover, about 50% of the soluble carbon source was outside of the sludge cell and could be released under mild hydrolysis condition. Whereas the absorbed amount of nitrogen was relatively low, and the removal rate of ammonia was only 13% . Furthermore, the releases of organic carbon, nitrogen and phosphorus from the sludge absorbing pollutants in the wastewater were studied. By comparing different hydrolysis conditions of normal (pH 7.5, 20 degrees C), heating (pH 7.5, 60 degrees C) and the alkaline heating (pH 11, 60 degrees C), the last one presented the optimum hydrolysis efficiency. Under which, the release rate of COD could reach 320 mg/g after 24 hours, whereas nitrogen and phosphorus just obtained low release rates of 18 mg/g and 2 mg/g, respectively. Results indicate that the carbon source in wastewater could be harvested by the adsorption and desorption of activated sludge, and the concentrations of nitrogen and phosphorus are low and would not influence the reuse of the harvested carbon source.

  14. Treatment of winery wastewater in a conventional municipal activated sludge process: five years of experience.

    Science.gov (United States)

    Bolzonella, D; Zanette, M; Battistoni, P; Cecchi, F

    2007-01-01

    A full-scale wastewater treatment plant where municipal and winery wastewaters were co-treated was studied for five years. The experimental results showed that suspended solids, COD, nitrogen and phosphorous were effectively removed both during the treatment of municipal wastewater and the cotreatment of municipal and winery wastewater. The sludge production increase from 4 tons to 5.5 tons per day during the harvesting and wine making period. In any case the specific sludge production was 0.2 kgMLVSS per kgCOD(removed) despite the organic loading increasing. About 70% of the COD was removed through respiration. Also the energy demand increased from 6,000 to 7,000 kWh per day. The estimated costs for the treatment of the winery wastewater was 0.2-0.3 Euros per m3 of treated wastewater. With reference to the process efficiency, the nitrogen removal was just 20%. The co-treatment of municipal and winery wastewater in conventional activated sludge processes can be a feasible solution for the treatment of these streams at relatively low costs.

  15. Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: Science or fiction? A review

    NARCIS (Netherlands)

    Ratsak, C.H.; Verkuijlen, J.

    2006-01-01

    Biological aerobic wastewater treatment plants (WWTPs) produce a lot of excess sludge. The costs for handling this residual product are increasing, so the search for alternative techniques to reduce the amount of sludge has to be continued. Activated sludge consists of inorganic and organic

  16. The role of diatomite particles in the activated sludge system for treating coal gasification wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.Q.; Rao, P.H.; Zhang, H.; Xu, J.L. [Shanghai University of Engineering Science, Shanghai (China)

    2009-02-15

    Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids (MLVSS) is increased from 4055 mg.L{sup -1} to 4518 mg.L{sup -1} and the average settling volume (SV) are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand (COD) and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlated to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.

  17. Kinetics of aerobically activated sludge on terylene artificial silk printing and dyeing wastewater treatment.

    Science.gov (United States)

    Guan, Bao-hong; Wu, Zhong-biao; Xu, Gen-liang

    2004-04-01

    Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics parameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the moderate-removal stage with B/Ckinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.

  18. Calibration of a complex activated sludge model for the full-scale wastewater treatment plant

    OpenAIRE

    Liwarska-Bizukojc, Ewa; Olejnik, Dorota; Biernacki, Rafal; Ledakowicz, Stanislaw

    2011-01-01

    In this study, the results of the calibration of the complex activated sludge model implemented in BioWin software for the full-scale wastewater treatment plant are presented. Within the calibration of the model, sensitivity analysis of its parameters and the fractions of carbonaceous substrate were performed. In the steady-state and dynamic calibrations, a successful agreement between the measured and simulated values of the output variables was achieved. Sensitivity analysis revealed that u...

  19. Effect of the presence of Actinomycetes in the activated sludge on the quality of the treated wastewater

    Directory of Open Access Journals (Sweden)

    Bezak-Mazur Elżbieta

    2017-01-01

    Full Text Available The aim of the study was to determine the effect of the Actinomycetes proliferation in the activated sludge on the quality of the treated wastewater and the sewage receiver. The river which is the sewage receiver flows near the wastewater treatment plant. The study was performed on the wastewater (raw and treated and on the river water samples (collected before and after wastewater discharge. The analysis of the research results, such as the content of total organic carbon (TOC, total phosphorus and oxygen consumption in the examined samples, permit the conclusion that the presence of relatively large population of the Actinomycetes in sewage sludge has a negative impact on the quality of the sewage receiver. Determining the effect of the Actinomycetes in the activated sludge on the wastewater treatment process involved the application of specific analyses, such as Sludge Biotic Index (SBI and the identification of filamentous bacteria in the activated sludge. The analysis of studies indicates that the presence of the Actinomycetes in the activated sludge adversely affects the efficiency of the wastewater treatment process.

  20. A Novel Method of Biological Start-up in Arak Activated Sludge Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Abdolreza Khalili

    2015-01-01

    Full Text Available Startup is one of the most important stages in the operation of a wastewater treatment plant (WWTP. In this paper, a novel method is presented for the startup of Arak Activated Sludge WWTP, which is shown to contain more advantages than other common methods. In this method, a portion of the inflow is initially allowed to enter gradually into an aeration basin prior to seeding. Under these conditions, less seeding is required due to the low flow of the influent and the low volume of the aeration basin. Once MLSS in the basin reaches the desired level, the rest of the system comes into operation and the sludge developed in the system is used for further seeding. In the case of the WWPT in Arak, it took about 2 months for the total MLSS to be developed and wasting the sludge to start because of the cold weather conditions in the region. The wasted sludge was controlled by the F/M ratio at a constant sludge age. During the start-up, the MLSS increase exhibited a linear trend and the low loading allowed for the variation in influent contaminants to be controlled. The effluent contaminants were below the standard levels recommended by the Environment Protection Organization. BOD5 and COD removals increased from 40% and 60% to 90% and TSS removal increased from 70% to 96%. Lower loading levels, better process control, and lower sludge processing costs are the benefits of this system

  1. APPLICATION OF RESPIROMETRIC TESTS FOR ASSESSMENT OF METHANOGENIC BACTERIA ACTIVITY IN WASTEWATER SLUDGE PROCESSING

    Directory of Open Access Journals (Sweden)

    Małgorzata Cimochowicz-Rybicka

    2013-07-01

    Full Text Available Production of a methane-rich gas (‘biogas’ is contemporary popular sludges processing technology which allows to generate thermal and/or electric energy. Formal requirements issued by the European Union to promote so called renewable energy resources made these process more attractive leading to its application in WWTPs which were designed based on different sludge handling processes. Authors (as active design engineers noted that dimensioning sludge digestion chamber is usually based on SRT assessment without any emphasis on sludge characteristics. Bio-mass characteristics and the estimation of its activity with respect to methane production are of great importance, from both scientific and practical points of view, as anaerobic digestion appears to be one of crucial processes in municipal wastewater handling and disposal. The authors propose respirometric tests to estimate a biomass potential to produce ‘a biogas’ and several years’ laboratory and full scale experience proved its usefulness and reliability both as a measurement and a design tool applicable in sludge handling. Dimensioning method proposed by authors, allows to construct and optimize operation of digestion chambers based on a methanogenic activity.

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

    Science.gov (United States)

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

    2016-07-01

    Algal-bacterial synergistic cultivation could be an optional wastewater treatment technology in temperate areas. In this study, a locally screened vigorous Chlorella strain was characterized and then it was used in a comparative study of wastewater treatment and nutrient recycle assessment via activated sludge (AS), microalgae and their combination systems. Chlorella sp. cultured with AS in light showed the best performance, in which case the removal efficiencies of COD, NH3-N and TP were 87.3%, 99.2% and 83.9%, respectively, within a short period of 1day. Algal-bacterial combination in light had the best settleability. Chlorella sp. contained biomass, could be processed to feed, fertilizer or fuel due to the improved quality (higher C/H/N) compared with sludge. PCR-DGGE analysis shows that two types of rhizobacteria, namely, Pseudomonas putida and Flavobacterium hauense were enriched in sludge when cultured with algae in light, serving as the basics for artificial consortium construction for improved wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

    Applications of activated sludge models (ASM) in simulating industrial biological wastewater treatment plants (WWTPs) are still difficult due to refractory and complex components in influents as well as diversity in activated sludges. In this study, an ASM3 modeling study was conducted to simulate and optimize a practical coking wastewater treatment plant (CWTP). First, respirometric characterizations of the coking wastewater and CWTP biomasses were conducted to determine the specific kinetic and stoichiometric model parameters for the consecutive aeration-anoxic-aeration (O-A/O) biological process. All ASM3 parameters have been further estimated and calibrated, through cross validation by the model dynamic simulation procedure. Consequently, an ASM3 model was successfully established to accurately simulate the CWTP performances in removing COD and NH4-N. An optimized CWTP operation condition could be proposed reducing the operation cost from 6.2 to 5.5 €/m(3) wastewater. This study is expected to provide a useful reference for mathematic simulations of practical industrial WWTPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Optimized biological nitrogen removal of high-strength ammonium wastewater by activated sludge modeling

    Directory of Open Access Journals (Sweden)

    Abdelsalam Elawwad

    2018-09-01

    Full Text Available Wastewater containing high ammonium concentrations is produced from various industrial activities. In this study, the author used a complex activated sludge model, improved by utilizing BioWin© (EnviroSim, Hamilton, Canada simulation software, to gain understanding of the problem of instability in biological nitrogen removal (BNR. Specifically, the study focused on BNR in an industrial wastewater treatment plant that receives high-strength ammonium wastewater. Using the data obtained from a nine-day sampling campaign and routinely measured data, the model was successfully calibrated and validated, with modifications to the sensitive stoichiometric and kinetic parameters. Subsequently, the calibrated model was employed to study various operating conditions in order to optimize the BNR. These operating conditions include alkalinity addition, sludge retention time, and the COD/N ratio. The addition of a stripping step and modifications to the configuration of the aerators are suggested by the author to increase the COD/N ratio and therefore enhance denitrification. It was found that the calibrated model could successfully represent and optimize the treatment of the high-strength ammonium wastewater.

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

    DEFF Research Database (Denmark)

    Gernaey, Krist; Loosdrecht, M.C.M. van; Henze, Mogens

    2004-01-01

    This review paper focuses on modelling of wastewater treatment plants (WWTP). White-box modelling is widely applied in this field, with learning, design and process optimisation as the main applications. The introduction of the ASM model family by the IWA task group was of great importance......, providing researchers and practitioners with a standardised. set of basis models. This paper introduces the nowadays most frequently used white-box models for description of biological nitrogen and phosphorus removal activated sludge processes. These models are mainly applicable to municipal wastewater...... systems, but can be adapted easily to specific situations such as the presence of industrial wastewater. Some of the main model assumptions are highlighted, and their implications for practical model application are discussed. A step-wise procedure leads from the model purpose definition to a calibrated...

  6. Production from Activated Sludge Process of Sago Industry Wastewater Using Central Composite Design

    Directory of Open Access Journals (Sweden)

    B. Subha

    2012-01-01

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

  7. Combining high-rate aerobic wastewater treatment with anaerobic digestion of waste activated sludge at a pulp and paper mill.

    Science.gov (United States)

    Magnusson, Björn; Ekstrand, Eva-Maria; Karlsson, Anna; Ejlertsson, Jörgen

    2018-05-01

    The activated sludge process within the pulp and paper industry is generally run to minimize the production of waste activated sludge (WAS), leading to high electricity costs from aeration and relatively large basin volumes. In this study, a pilot-scale activated sludge process was run to evaluate the concept of treating the wastewater at high rate with a low sludge age. Two 150 L containers were used, one for aeration and one for sedimentation and sludge return. The hydraulic retention time was decreased from 24 hours to 7 hours, and the sludge age was lowered from 12 days to 2-4 days. The methane potential of the WAS was evaluated using batch tests, as well as continuous anaerobic digestion (AD) in 4 L reactors in mesophilic and thermophilic conditions. Wastewater treatment capacity was increased almost four-fold at maintained degradation efficiency. The lower sludge age greatly improved the methane potential of the WAS in batch tests, reaching 170 NmL CH 4 /g VS at a sludge age of 2 days. In addition, the continuous AD showed a higher methane production at thermophilic conditions. Thus, the combination of high-rate wastewater treatment and AD of WAS is a promising option for the pulp and paper industry.

  8. 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: kb@envs.au.dk [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark)

    2015-10-15

    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

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

    International Nuclear Information System (INIS)

    Escolà Casas, Mònica; Chhetri, Ravi Kumar; Ooi, Gordon; Hansen, Kamilla M.S.; Litty, Klaus; Christensson, Magnus; Kragelund, Caroline; Andersen, Henrik R.; Bester, Kai

    2015-01-01

    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 −1 , from 0 to 7.78 × 10 −1 h −1 , from 0 to 7.86 × 10 −1 h −1 and from 0 to 1.07 × 10 −1 h −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 during the first treatment step

  10. A study of aeration treatment of uranium-contained wastewater by saccharomyces cerevisiae-activated sludge

    International Nuclear Information System (INIS)

    Xia Liangshu; Chen Zhongqing

    2006-01-01

    Experiments of the aeration treatment of uranium-contained wastewater by saccharomyces cerevisiae-activated sludge were carried out. The experimental results indicate that, saccharomyces cerevisiae (S.C) can accumulate UO 2 2+ effectively from aqueous solution: the removal ratio of 100 mg·L -1 UO 2 2+ is 78.2% when S.C dosage is 10 g·L -1 , while with 8 g·L -1 activated sludge (A.S.) added in the solution the ratio has increased to 96.3%; then, 5-10 min effluent settling is clarified as a result of sludge flocculation; the optimum conditions of biosorption of U from wastewater by S.C.-A.S. are at pH 5, A.S concentration=8 g·L -1 , added dry weight of S.C.=10 g·L -1 , granularity of S.C=100-120 mesh; the quantity of U increases with the enhanced initial concentration of UO 2 2+ in the process of biosorption by S.C.-A.S., but the removal ratio decreases. The uptake of U could be described by the Freundlich and the Langmuir adsorption isotherms, which demonstrated that the adsorption was regarded as a physical adsorption. (authors)

  11. Extraction of bioflocculants from activated sludge and their application to wastewater treatment

    Directory of Open Access Journals (Sweden)

    Vasilieva Zh. V.

    2018-03-01

    Full Text Available Extracellular polymeric substances (EPS – biopolymers produced by the microorganisms – are effective flocculants of wastewater pollution and lack the shortcomings of traditional coagulants and flocculants, which can pose direct threat to health and human life, as well as to the sustainable existence of aquatic and terrestrial ecosystems. EPS do not form secondary contamination of their degradation intermediates, are biodegradable and eco-friendly. Industrial production of bacterial EPS is associated with high cost of growing specific microbial biomass and the functioning of technologies for the synthesis of microbial products. At the same time, there is an underused resource of excess activated sludge, which can be used as cheap substrate for producing bioflocculants and a possible measure to reduce costs. The conducted researches have shown the prospects of extracting EPS from excess activated sludge for their subsequent use as wastewater treatment bioflocculants. EPS extraction has been conducted using three methods: combination of centrifugation processes, extraction using the aqueous solution of disodium ethylenediaminetetraacetic acid, and precipitation with isopropyl alcohol (the EDTA method; combination of centrifugation, extraction with (NH22CO, precipitation and ethanol reprecipitation (the (NH22CO method; combination of activated sludge ultrasonic treatment, centrifugation, extraction with glacial acetic acid, and precipitation with acetone (the CH3COOH method. The research has shown that the extraction method affects not only the efficiency of EPS extraction, but also the possibility of EPS application for the purification of certain types of sewage. The (NH22CO method has shown the best extraction efficiency, but at the same time EPSs produced have not be able to perform fish processing wastewater treatment. The EDTA and CH3COOH methods are more preferable for producing efficient bioflocculants for fish processing wastewater

  12. A review of modeling approaches in activated sludge systems

    African Journals Online (AJOL)

    use

    Key words: Mathematical modeling, water, wastewater, wastewater treatment plants, activated sludge systems. INTRODUCTION ... sedimentation processes which take place in the aeration ...... activated sludge waste water treatment systems.

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Treatment of real wastewater using co-culture of immobilized Chlorella vulgaris and suspended activated sludge.

    Science.gov (United States)

    Mujtaba, Ghulam; Lee, Kisay

    2017-09-01

    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.

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

    Science.gov (United States)

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

    2008-01-01

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

  16. Estimation of Viable Biomass In Wastewater And Activated Sludge By Determination of ATP, Oxygen Utilization Rate And FDA Hydrolysis

    DEFF Research Database (Denmark)

    Jørgensen, Poul-Erik; Eriksen, T.; Jensen, B.K.

    1992-01-01

    ATP content, oxygen utilization rate (OUR) and fluorescein diacetate (FDA) hydrolysis were tested for the ability to express the amount of viable biomass in wastewater and activated sludge. The relationship between biomass and these activity parameters was established in growth cultures made...... with biomass, while FDA hydrolysis in the sludge failed to show any such correlation. Conversion factors of 3 mg ATP/g dw, 300 mg O2/h g dw and 0.4 A/h (mg dw/ml) for ATP, OUR and FDA methods, respectively, were calculated. When the methods were applied for in situ determinations in four different wastewater...... plants, it was found that ATP content and respiration rate estimated viable biomass to range from 81 to 293 mg dw/g SS for raw wastewater and from 67 to 187 mg dw/g SS for activated sludge with a rather weak correlation between ATP and respiration measurements. The FDA hydrolysis estimated viable biomass...

  17. Wastewater and sludge management and research in Oman: An overview.

    Science.gov (United States)

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

    2017-03-01

    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.

  18. Use of Lecane rotifers for limiting Thiothrix filamentous bacteria in bulking activated sludge in a dairy wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Kowalska Ewa

    2014-01-01

    Full Text Available Excessive growth of filamentous bacteria is a serious problem in many dairy wastewater treatment plants (WWTPs. The objective of the study was to determine whether Lecane inermis rotifers were able to reduce the density of Thiothrix bacteria in activated sludge originating from a dairy WWTP, as well as to identify the impact of rotifers on other organisms in sludge. On a laboratory scale, three experiments were conducted in which activated sludge with a predominance of Thiothrix was inoculated with rotifers at an initial concentration of app. 600 individuals/mL. The results showed that the rotifers, by feeding on the bacterium filaments, are able to reduce significantly the quantity of Thiothrix. A decline in Thiothrix abundance coincided with an improvement of the sedimentation properties of activated sludge. In addition, it was proven that Lecane inermis did not negatively affect the number of Protozoa and Metazoa in activated sludge.

  19. Production of polyhydroxyalcanoates (PHAs) using milk whey and dairy wastewater activated sludge production of bioplastics using dairy residues.

    Science.gov (United States)

    Bosco, Francesca; Chiampo, Fulvia

    2010-04-01

    The production of polyhydroxyalcanoates (PHAs), which are biodegradable plastics, was studied using milk whey and dairy wastewater activated sludge to define a suitable C/N ratio, the pre-treatments required to reduce the protein content, and the effect of pH correction. The results show good production of PHAs at a C/N=50 and without pH correction. The use of dairy wastewater activated sludge has the advantage of not requiring aseptic conditions. Copyright 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Effect of Using Effective Microorganisms EM-1 on the Performance of Extended Aeration Activated Sludge in Treating Domestic Wastewater

    Directory of Open Access Journals (Sweden)

    Waleed M. Sheet

    2013-05-01

    Full Text Available       This research concerning with the effect of using the effective microorganisms on the efficiency of extended Aeration Activated Sludge Units which consist from many strain of Bacteria, Fungi and Actinomycetes  in addition to board spectrum of nutrient and elements which important to growth, The use of this product is practically applied by using two bench scale laboratory units where they are operated to treat the wastewater after completing and preparing the activated sludge units to work under the same conditions of temperature and detention time (DT.54One bench scale is fed with wastewater and the other is operated by using a mixture of EM-1 along with the wastewater. It is noticed that the use of EM-1 with wastewater has reduced the smell resulting from disintegration in the aeration basin. Further, the color of sludge in the unit where EM-1 is added is light brown which means more activity and vitality. Besides, the concentration of mixed liquor volatile suspended solids (MLVSS is increased by using EM-1 by 30% due to the increase of nutrients and a reduction in the sludge volume index (SVI which is an important factor in the performance of the secondary settling basins which means a reduction in bulking of sludge, which is considered one of the most notable operating problem in activated sludge units. As a result bulking of sludge reduced by25% when EM-1 is used. Thus, EM-1 has participated in solving three important operating problems suffered by operators of these treatment units easily and without using complicated technologies or appliances. Further, EM-1 improves the removal efficiency of the units about 6-8% due to the reduction in chemical oxygen demand in the treated wastewater leaving the unit by 32%.

  1. Respirometry in activated sludge

    NARCIS (Netherlands)

    Spanjers, H.

    1993-01-01

    The purpose of the study was (1) to develop a respiration meter capable of continuously measuring, using different procedures, the oxygen uptake rate of activated sludge and (2) to expand knowledge about respiration related characteristics of wastewater and activated sludge.

    A

  2. Ignored fungal community in activated sludge wastewater treatment plants: diversity and altitudinal characteristics.

    Science.gov (United States)

    Niu, Lihua; Li, Yi; Xu, Lingling; Wang, Peifang; Zhang, Wenlong; Wang, Chao; Cai, Wei; Wang, Linqiong

    2017-02-01

    Fungi are important contributors to the various functions of activated sludge wastewater treatment plants (WWTPs); however, the diversity and geographic characteristics of fungal populations have remained vastly unexplored. Here, quantitative polymerase chain reaction and 454 pyrosequencing were combined to investigate the abundance and diversity of the activated sludge fungal communities from 18 full-scale municipal WWTPs in China. Phylogenetic taxonomy revealed that the members of the fungal communities were assigned to 7 phyla and 195 genera. Ascomycota and Basidiomycota were the most abundant phyla, dominated by Pluteus, Wickerhamiella, and Penicillium. Twenty-three fungal genera, accounting for 50.1 % of the total reads, were shared by 18 WWTPs and constituted a core fungal community. The fungal communities presented similar community diversity but different community structures across the WWTPs. Significant distance decay relationships were observed for the dissimilarity in fungal community structure and altitudinal distance between WWTPs. Additionally, the community evenness increased from 0.25 to 0.7 as the altitude increased. Dissolved oxygen and the C/N ratio were determined to be the most dominant contributors to the variation in fungal community structure via redundancy analysis. The observed data demonstrated the diverse occurrence of fungal species and gave a marked view of fungal community characteristics based on the previously unexplored fungal communities in activated sludge WWTPs.

  3. Activated sludge is a potential source for production of biodegradable plastics from wastewater.

    Science.gov (United States)

    Khardenavis, A; Guha, P K; Kumar, M S; Mudliar, S N; Chakrabarti, T

    2005-05-01

    Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.

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

    OpenAIRE

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

    2013-01-01

    The structure of microbial consortia in wastewater treatment facilities is a resultant of environmental conditions created by the operational parameters of the purification process. In the research, activated sludge from nine Polish wastewater treatment plants (WWTPs) was investigated at a molecular level to determine the impact of the complexity of biological treatment line and the influent composition on the species structure and the diversity of bacterial consortia. The community fingerpri...

  5. Effluent quality of a conventional activated sludge and a membrane bioreactor system treating hospital wastewater

    International Nuclear Information System (INIS)

    Pauwels, B.; Ngwa, F.; Deconinck, S.; Verstraete, W.

    2005-01-01

    Two lab scale wastewater treatment plants treating hospital wastewater in parallel were compared in terms of performance characteristics. One plant consisted of a conventional activated sludge system (CAS) and comprised In anoxic and aerobic compartment followed by a settling tank with recycle loop. The second pilot plant was a -late membrane bioreactor (MBR). The wastewater as obtained from the hospital had a variable COD (Chemical Oxygen Demand) ranging from 250 to 2300 mg/L. Both systems were operated at a similar hydraulic residence time of 12 hours. The reference conventional activated sludge system did not meet the regulatory standard for effluent COD of 125 mg /L most of the time. Its COD removal efficiency was 88%. The plate MBR delivered an effluent with a COD value of 50 mg/L or less, and attained an efficiency of 93%. The effluent contained no suspended particles. In addition, the MBR resulted in consistent operational parameters with a flux remaining around 8 -10 L/m/sup 2/.h and a trans membrane pressure <0.1 bar without the need for backwash or chemical cleaning. The CAS and the MBR system performed equally good in terms of TAN removal and EE2 removal. The CAS system typically decreased bacterial groups for about 1 log unit, whereas the MBR decreased these groups for about 3 log units. Enterococci were decreased below the detection limit in the MBR and indicator organisms such as fecal coliforms were decreased for 1.4 log units in the CAS system compared to a 3.6 log removal in the MBR. (author)

  6. Cost estimation and economical evaluation of three configurations of activated sludge process for a wastewater treatment plant (WWTP) using simulation

    Science.gov (United States)

    Jafarinejad, Shahryar

    2017-09-01

    The activated sludge (AS) process is a type of suspended growth biological wastewater treatment that is used for treating both municipal sewage and a variety of industrial wastewaters. Economical modeling and cost estimation of activated sludge processes are crucial for designing, construction, and forecasting future economical requirements of wastewater treatment plants (WWTPs). In this study, three configurations containing conventional activated sludge (CAS), extended aeration activated sludge (EAAS), and sequencing batch reactor (SBR) processes for a wastewater treatment plant in Tehran city were proposed and the total project construction, operation labor, maintenance, material, chemical, energy and amortization costs of these WWTPs were calculated and compared. Besides, effect of mixed liquor suspended solid (MLSS) amounts on costs of WWTPs was investigated. Results demonstrated that increase of MLSS decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS. In addition, increase of this value increases the total operation, maintenance and energy costs, but does not affect chemical cost of WWTPs containing EAAS and CAS.

  7. 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

    2013-01-01

    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.

  8. Achieving partial nitrification in a novel six basins alternately operating activated sludge process treating domestic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, Rusul Naseer; Arab, Saad; Xiwu, Lu [Southeast University, Nanjing (China)

    2013-11-15

    A novel technology was developed to achieve partial nitrification at moderately low DO and short HRT, which would save the aeration cost and have the capacity to treat a wide range of low-strength real wastewater. The process enables a relatively stable whereas nitrite accumulation rate (NO{sub 2}-AR) was stabilized over 94% in the last aerobic basin on average of each phase through a combination of short HRT and low DO level. Low DO did not produce sludge with poorer settleability. The morphology and internal structure of the granular sludge was observed by using a scanning electron microscope (SEM) analysis during a long-term operation. The images indicated that thick clusters of spherical cells and small rod-shaped cells (NOB and AOB are rod-shaped to spherical cells) were the dominant population structure, rather than filamentous and other bacteria under a combination of low DO and short HRT, which gives a good indication of nitrite accumulation achievement. MPN method was used to correlate AOB numbers with nutrient removal. It showed that an ammonia-oxidizing bacterium (AOB) was the dominant nitrifying bacteria, whereas high NO{sub 2}-AR was achieved at AOB number of 5.33x10{sup 8} cell/g MLSS. Higher pollutant removal efficiency of 86.2%, 98% and 96.1%, for TN, NH{sub 4}{sup +}-N, and TP, respectively, was achieved by a novel six basin activated sludge process (SBASP) at low DO level and low C/N ratio which were approximately equal to the complete nitrification-denitrification with the addition of sodium acetate (NaAc) at normal DO level of (1.5-2.5 mg/L)

  9. Multistage A-O Activated Sludge Process for Paraformaldehyde Wastewater Treatment and Microbial Community Structure Analysis

    Directory of Open Access Journals (Sweden)

    Danyang Zheng

    2016-01-01

    Full Text Available In recent years, the effect of formaldehyde on microorganisms and body had become a global public health issue. The multistage combination of anaerobic and aerobic process was adopted to treat paraformaldehyde wastewater. Microbial community structure in different reaction stages was analyzed through high-throughput sequencing. Results showed that multistage A-O activated sludge process positively influenced polyformaldehyde wastewater. The removal rates of formaldehyde were basically stable at more than 99% and those of COD were about 89%. Analysis of the microbial diversity index indicated that the microbial diversity of the reactor was high, and the treatment effect was good. Moreover, microbial community had certain similarity in the same system. Microbial communities in different units also showed typical representative characteristics affected by working conditions and influent concentrations. Proteobacteria, Firmicutes, and Bacteroidetes were the dominant fungal genera in the phylum level of community composition. As to family and genus levels, Peptostreptococcaceae was distributed at various stages and the dominant in this system. This bacterium also played an important role in organic matter removal, particularly decomposition of the acidified middle metabolites. In addition, Rhodobacteraceae and Rhodocyclaceae were the formaldehyde-degrading bacteria found in the reactor.

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

    Science.gov (United States)

    Estrada, José M; Kraakman, N J R; Lebrero, R; Muñoz, R

    2015-11-01

    Traditional physical/chemical end-of-the-pipe technologies for odor abatement are relatively expensive and present high environmental impacts. On the other hand, biotechnologies have recently emerged as cost-effective and environmentally friendly alternatives but are still limited by their investment costs and land requirements. A more desirable approach to odor control is the prevention of odorant formation before being released to the atmosphere, but limited information is available beyond good design and operational practices of the wastewater treatment process. The present paper reviews two widely applicable and economic alternatives for odor control, Activated Sludge Recycling (ASR) and Oxidized Ammonium Recycling (OAR), by discussing their fundamentals, key operating parameters and experience from the available pilot and field studies. Both technologies present high application potential using readily available plant by-products with a minimum plant upgrading, and low investment and operating costs, contributing to the sustainability and economic efficiency of odor control at wastewater treatment facilities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Fluidization of Dried Wastewater Sludge.

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Pohořelý, Michael; Trnka, Otakar

    2007-01-01

    Roč. 178, 3 (2007) , s. 166-172 ISSN 0032-5910 R&D Projects: GA AV ČR(CZ) IAA4072201 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidization characteristics * multiphase reactors * dried stabilized wastewater sludge Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.130, year: 2007

  12. Sorption and release of organics by primary, anaerobic, and aerobic activated sludge mixed with raw municipal wastewater.

    Directory of Open Access Journals (Sweden)

    Oskar Modin

    Full Text Available New activated sludge processes that utilize sorption as a major mechanism for organics removal are being developed to maximize energy recovery from wastewater organics, or as enhanced primary treatment technologies. To model and optimize sorption-based activated sludge processes, further knowledge about sorption of organics onto sludge is needed. This study compared primary-, anaerobic-, and aerobic activated sludge as sorbents, determined sorption capacity and kinetics, and investigated some characteristics of the organics being sorbed. Batch sorption assays were carried out without aeration at a mixing velocity of 200 rpm. Only aerobic activated sludge showed net sorption of organics. Sorption of dissolved organics occurred by a near-instantaneous sorption event followed by a slower process that obeyed 1st order kinetics. Sorption of particulates also followed 1st order kinetics but there was no instantaneous sorption event; instead there was a release of particles upon mixing. The 5-min sorption capacity of activated sludge was 6.5±10.8 mg total organic carbon (TOC per g volatile suspend solids (VSS for particulate organics and 5.0±4.7 mgTOC/gVSS for dissolved organics. The observed instantaneous sorption appeared to be mainly due to organics larger than 20 kDa in size being sorbed, although molecules with a size of about 200 Da with strong UV absorbance at 215-230 nm were also rapidly removed.

  13. Impacts of multiwalled carbon nanotubes on nutrient removal from wastewater and bacterial community structure in activated sludge.

    Directory of Open Access Journals (Sweden)

    Reti Hai

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

  14. Degradation of organic pollutants and characteristics of activated sludge in an anaerobic/anoxic/oxic reactor treating chemical industrial wastewater

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2014-09-01

    Full Text Available A laboratory-scale anaerobic/anoxic/oxic system operated at the hydraulic retention times (HRT of 20, 40, and 60 h with mixed liquor suspended solids (MLSS concentrations of 3 g/L and 6 g/L was considered for treating chemical industrial wastewater rich in complex organic compounds and total dissolved solids. Extending the HRT and increasing the MLSS concentration resulted in higher removal efficiency for chemical oxygen demand at 72%. Organic compounds in wastewater could be classified into easily-removed and refractory compounds during treatment. The easily-removed compounds consisted primarily of ethers, alcohols, and aldehydes, whereas the refractory compounds included mainly oxygen-containing heterocyclic and benzene-containing compounds. Results from energy-dispersive X-ray spectroscopy showed that several metal ions accumulated in activated sludge, particularly Fe(III. Fe accumulated mainly on the surface of sludge floc pellets and resulted in the compactness of activated sludge, which caused the values of mixed liquor volatile suspended solids /MLSS and sludge volume index to decrease.

  15. Treatment of coke-oven wastewater with the powdered activated carbon-contact stabilization activated sludge process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suidan, M.T.; Deady, M.A.; Gee, C.S.

    1983-11-01

    The objective of the study was to determine optimum parameters for the operation of an innovative process train used in the treatment of coke-over wastewater. The treatment process train consisted of a contact-stabilization activated sludge system with powdered activated carbon (PAC) addition, followed by activated sludge nitrification, followed by denitrification in an anoxic filter. The control and operating parameters evaluated during the study were: (a) the average mixed-liquor PAC concentration maintained in the contact-stabilization system, (b) the solids retention time practiced in the contact-stabilization system, and (c) the hydraulic detention time maintained in the contact aeration tank. Three identical treatement process trains were constructed and employed in this study. The coke-oven wastewater used for this investigation was fed to the treatment units at 30% strength. The first part of the study was devoted to determining the interactions between the mixed liquor PAC concentration and the solids retention time in the contact-stabilization tanks. Results showed that optimum overall system performance is attainable when the highest sludge age (30 day) and highest mixed liquor PAC concentration were practiced. During the second phase of the study, all three systems were operated at a 30 day solids retention time while different detention times of 1, 2/3 and 1/3 day were evaluated in the contact tank. PAC addition rates were maintained at the former levels and, consequently, reduced contact times entailed higher mixed liquor carbon concentrations. Once again, the system receiving the highest PAC addition rate of PAC exhibited the best overall performance. This system exhibited no deterioration in process performance as a result of decreased contact detention time. 72 references, 41 figures, 24 tables.

  16. Calibration of a complex activated sludge model for the full-scale wastewater treatment plant.

    Science.gov (United States)

    Liwarska-Bizukojc, Ewa; Olejnik, Dorota; Biernacki, Rafal; Ledakowicz, Stanislaw

    2011-08-01

    In this study, the results of the calibration of the complex activated sludge model implemented in BioWin software for the full-scale wastewater treatment plant are presented. Within the calibration of the model, sensitivity analysis of its parameters and the fractions of carbonaceous substrate were performed. In the steady-state and dynamic calibrations, a successful agreement between the measured and simulated values of the output variables was achieved. Sensitivity analysis revealed that upon the calculations of normalized sensitivity coefficient (S(i,j)) 17 (steady-state) or 19 (dynamic conditions) kinetic and stoichiometric parameters are sensitive. Most of them are associated with growth and decay of ordinary heterotrophic organisms and phosphorus accumulating organisms. The rankings of ten most sensitive parameters established on the basis of the calculations of the mean square sensitivity measure (δ(msqr)j) indicate that irrespective of the fact, whether the steady-state or dynamic calibration was performed, there is an agreement in the sensitivity of parameters.

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

    Directory of Open Access Journals (Sweden)

    Davood Nourmohammadi

    2013-01-01

    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.

  18. THE EFFECT OF THE SLUDGE RECYCLE RATIO IN AN ACTIVATED SLUDGE SYSTEM FOR THE TREATMENT OF AMOL'S INDUSTRIAL PARK WASTEWATER

    Directory of Open Access Journals (Sweden)

    BAHAR HOSSEINI

    2008-09-01

    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.

  19. THE INFLUENCE OF CALCIUM HYPOCHLORITE DOSAGE ADJUSTMENT ON TAPIOCA WASTEWATER PRE-CHLORINATION TOWARD EFFICIENCY OF ACTIVATED SLUDGE TREATMENT

    Directory of Open Access Journals (Sweden)

    Happy Mulyani

    2016-11-01

    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.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    The occurrence, removal and ecotoxicological assessment of 21 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, antiepileptics, antilipidemics and antihypersensitives, were studied at four municipal wastewater treatment plants (WWTP) in Chongqing, the Three Gorges Reservoir Area. Individual treatment unit effluents, as well as primary and secondary sludge, were sampled and analyzed for the selected PhACs to evaluate their biodegradation, persistence and partitioning behaviors. PhACs were identified and quantified using high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. All the 21 analyzed PhACs were detected in wastewater and the target PhACs except acetaminophen, ibuprofen and gemfibrozil, were also found in sludge. The concentrations of the antibiotics and SVT were comparable to or even higher than those reported in developed countries, while the case of other target PhACs was opposite. The elimination of PhACs except acetaminophen was incomplete and a wide range of elimination efficiencies during the treatment were observed, i.e. from “negative removal” to 99.5%. The removal of PhACs was insignificant in primary and disinfection processes, and was mainly achieved during the biological treatment. Based on the mass balance analysis, biodegradation is believed to be the primary removal mechanism, whereas only about 1.5% of the total mass load of the target PhACs was removed by sorption. Experimentally estimated distribution coefficients ( 2 O) in effluent and sludge, as well as the mixture of the 21 detected PhACs in effluent, sludge and receiving water had a significant ecotoxicological risk to algae. Therefore, further control of PhACs in effluent and sludge is required before their discharge and application to prevent their introduction into the environment. - Highlights: • All the 21 analyzed PhACs were detected in wastewater and 18 in sludge. • The removal of PhACs was insignificant

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

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Qing, E-mail: qyan2005@hotmail.com [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); College of Geography Science and Tourism, Chongqing Normal University, Chongqing 400047 (China); Gao, Xu, E-mail: gaoxu@cqu.edu.cn [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chen, You-Peng [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Peng, Xu-Ya; Zhang, Yi-Xin; Gan, Xiu-Mei; Zi, Cheng-Fang [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Guo, Jin-Song [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China)

    2014-02-01

    The occurrence, removal and ecotoxicological assessment of 21 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, antiepileptics, antilipidemics and antihypersensitives, were studied at four municipal wastewater treatment plants (WWTP) in Chongqing, the Three Gorges Reservoir Area. Individual treatment unit effluents, as well as primary and secondary sludge, were sampled and analyzed for the selected PhACs to evaluate their biodegradation, persistence and partitioning behaviors. PhACs were identified and quantified using high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. All the 21 analyzed PhACs were detected in wastewater and the target PhACs except acetaminophen, ibuprofen and gemfibrozil, were also found in sludge. The concentrations of the antibiotics and SVT were comparable to or even higher than those reported in developed countries, while the case of other target PhACs was opposite. The elimination of PhACs except acetaminophen was incomplete and a wide range of elimination efficiencies during the treatment were observed, i.e. from “negative removal” to 99.5%. The removal of PhACs was insignificant in primary and disinfection processes, and was mainly achieved during the biological treatment. Based on the mass balance analysis, biodegradation is believed to be the primary removal mechanism, whereas only about 1.5% of the total mass load of the target PhACs was removed by sorption. Experimentally estimated distribution coefficients (< 500 L/kg, with a few exceptions) also indicate that biodegradation/transformation was responsible for the removal of the target PhACs. Ecotoxicological assessment indicated that the environment concentrations of single compounds (including sulfadiazine, sulfamethoxazole, ofloxacin, azithromycin and erythromycin-H{sub 2}O) in effluent and sludge, as well as the mixture of the 21 detected PhACs in effluent, sludge and receiving water had a significant

  2. Fate and distribution of pharmaceuticals in wastewater and sewage sludge of the conventional activated sludge (CAS) and advanced membrane bioreactor (MBR) treatment.

    Science.gov (United States)

    Radjenović, Jelena; Petrović, Mira; Barceló, Damià

    2009-02-01

    In this paper we report on the performances of full-scale conventional activated sludge (CAS) treatment and two pilot-scale membrane bioreactors (MBRs) in eliminating various pharmaceutically active compounds (PhACs) belonging to different therapeutic groups and with diverse physico-chemical properties. Both aqueous and solid phases were analysed for the presence of 31 pharmaceuticals included in the analytical method. The most ubiquitous contaminants in the sewage water were analgesics and anti-inflammatory drugs ibuprofen (14.6-31.3 microg/L) and acetaminophen (7.1-11.4 microg/L), antibiotic ofloxacin (0.89-31.7 microg/L), lipid regulators gemfibrozil (2.0-5.9 microg/L) and bezafibrate (1.9-29.8 microg/L), beta-blocker atenolol (0.84-2.8 microg/L), hypoglycaemic agent glibenclamide (0.12-15.9 microg/L) and a diuretic hydrochlorothiazide (2.3-4.8 microg/L). Also, several pharmaceuticals such as ibuprofen, ketoprofen, diclofenac, ofloxacin and azithromycin were detected in sewage sludge at concentrations up to 741.1, 336.3, 380.7, 454.7 and 299.6 ng/g dry weight. Two pilot-scale MBRs exhibited enhanced elimination of several pharmaceutical residues poorly removed by the CAS treatment (e.g., mefenamic acid, indomethacin, diclofenac, propyphenazone, pravastatin, gemfibrozil), whereas in some cases more stable operation of one of the MBR reactors at prolonged SRT proved to be detrimental for the elimination of some compounds (e.g., beta-blockers, ranitidine, famotidine, erythromycin). Moreover, the anti-epileptic drug carbamazepine and diuretic hydrochlorothiazide by-passed all three treatments investigated. Furthermore, sorption to sewage sludge in the MBRs as well as in the entire treatment line of a full-scale WWTP is discussed for the encountered analytes. Among the pharmaceuticals encountered in sewage sludge, sorption to sludge could be a relevant removal pathway only for several compounds (i.e., mefenamic acid, propranolol, and loratidine). Especially in the

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

    Science.gov (United States)

    Morales, Gabriela; Pesante, Silvana; Vidal, Gladys

    2015-01-01

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

  4. 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

    2015-01-01

    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...... in significantly lower biodegradation for 4 out of 6 examined compounds. Calculation of specific removal rates (normalised to biomass) revealed that attached biomass had higher biodegradation potential for target compounds comparing to suspended biomass. Clear differences in the biodegradation ability of attached...... 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....

  5. Depuration of olive oil mill wastewater by an activated sludge system; Depuracion de alpechin mediante us sistema de fangos activados

    Energy Technology Data Exchange (ETDEWEB)

    Beltran de Heredia, J.; Torregrosa Anton, J.; Ramos Viscas, M. P.; Garcia Rodriguez, J.; Dominguez Vargas, R. [Universidad de Extremadura. Badajoz (Spain)

    1999-07-01

    In the present work, the degradation of alpechin (olive oil mill wastewaters) have been studied by an activated sludge treatment. The substrate evolution (based on COD and BOD{sub 5}), nitrogen Kjeldahl, phosphorus, biomass, aromaticity and total polyphenolic contents was followed during each experiment. A kinetic study is performed by using the Contois model, which applied to the experimental data, provides the specific kinetic parameters of this model. Moreover, others interesting biological parameters like the cellular yield and the kinetics of endogenous metabolism were determined. (Author) 17 refs.

  6. 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.

    1997-01-01

    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

  7. Electrodialytic removal of cadmium from wastewater sludge

    DEFF Research Database (Denmark)

    Jakobsen, M. R.; Fritt-Rasmussen, Janne; Nielsen, S.

    2004-01-01

    This paper presents for the first time laboratory results demonstrating electrodialytic removal of Cd from wastewater sludge, which is a method originally developed for soil remediation. During the remediation a stirred suspension of wastewater sludge was exposed to an electric dc field. The liquid....../solid (ml/g fresh sludge) ratio was between 1.4 and 2. Three experiments were performed where the sludge was suspended in distilled water, citric acid or HNO"3. The experimental conditions were otherwise identical. The Cd removal in the three experiments was 69, 70 and 67%, respectively, thus the removal...... was approximately the same. Chemical extraction experiments with acidic solutions showed that 5-10 times more Cd could be extracted from decomposed sludge than from fresh sludge. It is likely that the mobilization of Cd during decomposition of the sludge contributes to the efficient removal of Cd...

  8. The Microbial Database for Danish wastewater treatment plants with nutrient removal (MiDas-DK) – a tool for understanding activated sludge population dynamics and community stability

    DEFF Research Database (Denmark)

    Mielczarek, Artur Tomasz; Saunders, Aaron Marc; Larsen, Poul

    2013-01-01

    Since 2006 more than 50 Danish full-scale wastewater treatment plants with nutrient removal have been investigated in a project called ‘The Microbial Database for Danish Activated Sludge Wastewater Treatment Plants with Nutrient Removal (MiDas-DK)’. Comprehensive sets of samples have been collected......, analyzed and associated with extensive operational data from the plants. The community composition was analyzed by quantitative fluorescence in situ hybridization (FISH) supported by 16S rRNA amplicon sequencing and deep metagenomics. MiDas-DK has been a powerful tool to study the complex activated sludge...

  9. 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.

    2007-07-01

    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.

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

    Science.gov (United States)

    Jaranowska, Paulina; Cydzik-Kwiatkowska, Agnieszka; Zielińska, Magdalena

    2013-07-01

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

  11. Nitrogen fixation in the activated sludge treatment of thermomechanical pulping wastewater: effect of dissolved oxygen.

    Science.gov (United States)

    Slade, A H; Anderson, S M; Evans, B G

    2003-01-01

    N-ViroTech, a novel technology which selects for nitrogen-fixing bacteria as the bacteria primarily responsible for carbon removal, has been developed to treat nutrient limited wastewaters to a high quality without the addition of nitrogen, and only minimal addition of phosphorus. Selection of the operating dissolved oxygen level to maximise nitrogen fixation forms a key component of the technology. Pilot scale activated sludge treatment of a thermomechanical pulping wastewater was carried out in nitrogen-fixing mode over a 15 month period. The effect of dissolved oxygen was studied at three levels: 14% (Phase 1), 5% (Phase 2) and 30% (Phase 3). The plant was operated at an organic loading of 0.7-1.1 kg BOD5/m3/d, a solids retention time of approximately 10 d, a hydraulic retention time of 1.4 d and a F:M ratio of 0.17-0.23 mg BOD5/mg VSS/d. Treatment performance was very stable over the three dissolved oxygen operating levels. The plant achieved 94-96% BOD removal, 82-87% total COD removal, 79-87% soluble COD removal, and >99% total extractives removal. The lowest organic carbon removals were observed during operation at 30% DO but were more likely to be due to phosphorus limitation than operation at high dissolved oxygen, as there was a significant decrease in phosphorus entering the plant during Phase 3. Discharge of dissolved nitrogen, ammonium and oxidised nitrogen were consistently low (1.1-1.6 mg/L DKN, 0.1-0.2 mg/L NH4+-N and 0.0 mg/L oxidised nitrogen). Discharge of dissolved phosphorus was 2.8 mg/L, 0.1 mg/L and 0.6 mg/L DRP in Phases 1, 2 and 3 respectively. It was postulated that a population of polyphosphate accumulating bacteria developed during Phase 1. Operation at low dissolved oxygen during Phase 2 appeared to promote biological phosphorus uptake which may have been affected by raising the dissolved oxygen to 30% in Phase 3. Total nitrogen and phosphorus discharge was dependent on efficient secondary clarification, and improved over the course of

  12. Application of contact stabilization activated sludge for enhancing biological phosphorus removal (EBPR in domestic wastewater

    Directory of Open Access Journals (Sweden)

    Ehab M. Rashed

    2014-04-01

    Full Text Available The experiment has been performed in order to investigate the effect of using contact stabilization activated sludge as an application of enhancing biological phosphorous removal (EBPR by using contact tank as a phosphorus uptake zone and using thickening tank as a phosphorus release zone. The study involved the construction of a pilot plant which was setup in Quhafa waste water treatment plant (WWTP that included contact, final sedimentation, stabilization and thickening tanks, respectively with two returns sludge in this system one of them to contact tank and another to stabilization tank. Then observation of the uptake and release of total phosphorus by achievement through two batch test using sludge samples from thickener and final sedimentations. Results showed the removal efficiencies of COD, BOD and TP for this pilot plant with the range of 94%, 85.44% and 80.54%, respectively. On the other hand the results of batch tests showed that the reason of high ability of phosphorus removal for this pilot plant related to the high performance of microorganisms for phosphorus accumulating. Finally the mechanism of this pilot plant depends on the removal of the phosphorus from the domestic waste water as a concentrated TP solution from the supernatant above the thickening zone not through waste sludge like traditional systems.

  13. Phytoremediation potential of water caltrop (Trapa natans L.) using municipal wastewater of the activated sludge process-based municipal wastewater treatment plant.

    Science.gov (United States)

    Kumar, Vinod; Chopra, A K

    2018-01-01

    Phytoremediation experiments were carried out to assess the phytoremediation potential of water caltrop (Trapa natans L.) using municipal wastewater collected from the activated sludge process- (ASP) based municipal wastewater treatment plant. The results revealed that T. natans significantly (P ≤ .05/P ≤ .01/P ≤ .001) reduced the contents of total dissolved solids (TDS), electrical conductivity (EC), biochemical oxygen demand (BOD 5 ), chemical oxygen demand, total Kjeldahl nitrogen, phosphate ([Formula: see text]), sodium (Na + ), potassium (K + ), calcium (Ca 2+ ), magnesium (Mg 2+ ), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn), standard plate count, and most probable number of the municipal wastewater after phytoremediation experiments. The maximum removal of these parameters was obtained at 60 days of the phytoremediation experiments, but the removal rate of these parameters was gradually increased from 15 to 45 days and it was slightly decreased at 60 days. Most contents of Cd, Cu, Fe, Mn and Zn were translocated in the leaves of T. natans, whereas most contents of Cr and Pb were accumulated in the root of T. natans after phytoremediation experiments. The contents of different biochemical components were recorded in the order of total sugar > crude protein > total ash > crude fiber > total fat in T. natans after phytoremediation of municipal wastewater. Therefore, T. natans was found to be effective for the removal of different parameters of municipal wastewater and can be used effectively to reduce the pollution load of municipal wastewater drained from the ASP-based treatment plants.

  14. Secondary clarifier hybrid model calibration in full scale pulp and paper activated sludge wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Sreckovic, G.; Hall, E.R. [British Columbia Univ., Dept. of Civil Engineering, Vancouver, BC (Canada); Thibault, J. [Laval Univ., Dept. of Chemical Engineering, Ste-Foy, PQ (Canada); Savic, D. [Exeter Univ., School of Engineering, Exeter (United Kingdom)

    1999-05-01

    The issue of proper model calibration techniques applied to mechanistic mathematical models relating to activated sludge systems was discussed. Such calibrations are complex because of the non-linearity and multi-model objective functions of the process. This paper presents a hybrid model which was developed using two techniques to model and calibrate secondary clarifier parts of an activated sludge system. Genetic algorithms were used to successfully calibrate the settler mechanistic model, and neural networks were used to reduce the error between the mechanistic model output and real world data. Results of the modelling study show that the long term response of a one-dimensional settler mechanistic model calibrated by genetic algorithms and compared to full scale plant data can be improved by coupling the calibrated mechanistic model to as black-box model, such as a neural network. 11 refs., 2 figs.

  15. Critical operational parameters for zero sludge production in biological wastewater treatment processes combined with sludge disintegration.

    Science.gov (United States)

    Yoon, Seong-Hoon; Lee, Sangho

    2005-09-01

    Mathematical models were developed to elucidate the relationships among process control parameters and the effect of these parameters on the performance of anoxic/oxic biological wastewater processes combined with sludge disintegrators (A/O-SD). The model equations were also applied for analyses of activated sludge processes hybrid with sludge disintegrators (AS-SD). Solubilization ratio of sludge in the sludge disintegrator, alpha, hardly affected sludge reduction efficiencies if the biomass was completely destructed to smaller particulates. On the other hand, conversion efficiency of non-biodegradable particulates to biodegradable particulates, beta, significantly affected sludge reduction efficiencies because beta was directly related to the accumulation of non-biodegradable particulates in bioreactors. When 30% of sludge in the oxic tank was disintegrated everyday and beta was 0.5, sludge reduction was expected to be 78% and 69% for the A/O-SD and AS-SD processes, respectively. Under this condition, the sludge disintegration number (SDN), which is the amount of sludge disintegrated divided by the reduced sludge, was calculated to be around 4. Due to the sludge disintegration, live biomass concentration decreased while other non-biodegradable particulates concentration increased. As a consequence, the real F/M ratio was expected to be much higher than the apparent F/M. The effluent COD was maintained almost constant for the range of sludge disintegration rate considered in this study. Nitrogen removal efficiencies of the A/O-SD process was hardly affected by the sludge disintegration until daily sludge disintegration reaches 40% of sludge in the oxic tank. Above this level of sludge disintegration, autotrophic biomass concentration decreases overly and TKN in the effluent increases abruptly in both the A/O-SD and AS-SD processes. Overall, the trends of sludge reduction and effluent quality according to operation parameters matched well with experimental results

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

    Science.gov (United States)

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

    2014-08-01

    Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl₂ as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. 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

    limited to no information is available for their ecophysiology in activated sludge. A combination of MAR-FISH and SIP was applied to identify members of the genera Rhodoferax, Dechloromonas and Sulfuritalea, all within the class Betaproteobacteria, to be core denitrifiers in these systems. Similar...... may explain why many of these core organisms have not attracted attention during the many years of research into the ecology of these systems. The future goal will be to obtain genome sequences for members of these core genera, applying recently developed protocols for the assembly of genomes from...

  18. The investigation of paper mill industry wastewater treatment and activated sludge properties in a submerged membrane bioreactor.

    Science.gov (United States)

    Erkan, Hanife Sari; Engin, Guleda Onkal

    2017-10-01

    The paper mill industry produces high amounts of wastewater and, for this reason, stringent discharge limits are applied for sustainable reclamation and reuse of paper mill industry wastewater in many countries. Submerged membrane bioreactor (sMBR) systems can create new opportunities to eliminate dissolved substances present in paper mill wastewater including. In this study, a sMBR was operated for the treatment of paper mill industry wastewater at 35 h of hydraulic retention time (HRT) and 40 d of sludge retention time (SRT). The chemical oxygen demand (COD), NH 3 -N and total phosphorus (TP) removal efficiencies were found to be 98%, 92.99% and 96.36%. The results demonstrated that sMBR was a suitable treatment for the removal of organic matter and nutrients for treating paper mill wastewater except for the problem of calcium accumulation. During the experimental studies, it was noted that the inorganic fraction of the sludge increased as a result of calcium accumulation in the reactor and increased membrane fouling was observed on the membrane surface due to the calcification problem encountered. The properties of the sludge, such as extracellular polymeric substances (EPS) and soluble microbial products (SMP), relative hydrophobicity, zeta potential and floc size distribution were also monitored. According to the obtained results, the total EPS was found to be 43.93 mg/gMLSS and the average total SMP rejection by the membrane was determined as 66.2%.

  19. Sludge Recycle of Wastewater Treatment Plant via its Application as Powdered Activated Carbon for Removal of Methyl Tertiary-Butyl Ether (MTBE from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    MR Zare

    2016-05-01

    Full Text Available Introduction: Nowadays, application of MTBE due to its physical and chemical characteristics including high solubility in water has been increased, resulting in its release into the water resources. On other hand, waste activated sludge derived from municipal wastewater treatment plant (MWTP contains high amount of carbon. Therefore, this study aimed to provide the activated carbon via sludge of MWTP as well as to evaluate its efficiency for MTBE removal. Methods: The effect of some parameters such as kind of activator, pH (2-10, contact time (0-240min, adsorbent dose (2-6g/L and initial concentration of MTBE (20-70mg/L was investigated on MTBE adsorption via activated carbon, after preparation of coal from wastewater sludge and activation of this coal via 3 molar solution of H2PO4,  and KOH as well as 5 molar solution of ZnCl2. MTBE concentration in solution was determined via Gas-Chromatography instrument. The obtained experimental data were modeled by adsorption model of Freundlich and Langmuir. Results: The maximum adsorbed MTBE per gram of activated carbon was obtained when the ZnCL2 was used as an activator; however, there was no statistically significant difference among different activators. In addition, maximum removal efficiency (about 50% was obtained in acidic pH of 4, 6g/L of activated carbon and 20mg/L of MTBE concentration. Results of adsorption isotherm showed that Freundlich adsorption model had a better compliance with the experimental data. Conclusion: Regarding the problems associated with sludge disposal of wastewater treatment plant, recycling of this sludge, as an adsorbent, can eliminate most of these problems. As a result, the economical features with respect to industrial scale application and the efficiency of this substance in removal of other pollutants are recommended to be investigated.

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

    Science.gov (United States)

    Safferman, Steven I; Burks, Bennette D; Parker, Robert A

    2004-01-01

    The need to improve on-site wastewater treatment processes is being realized as populations move into more environmentally sensitive regions and regulators adopt the total maximum daily load approach to watershed management. Under many conditions, septic systems do not provide adequate treatment; therefore, advanced systems are required. These systems must remove significant amounts of biochemical oxygen demand (BOD) and suspended solids, and substantially nitrify, denitrify, and remove phosphorus. Many existing advanced on-site wastewater systems effectively remove BOD, suspended solids, and ammonia, but few substantially denitrify and uptake phosphorus. The purpose of this research was to design and test modifications to an existing on-site wastewater treatment system to improve denitrification and phosphorus removal. The Nayadic (Consolidated Treatment Systems, Inc., Franklin, Ohio), an established, commercially available, extended-aeration, activated sludge process, was used to represent a typical existing system. Several modifications were considered based on a literature review, and the option with the best potential was tested. To improve denitrification, a supplemental treatment tank was installed before the Nayadic and a combination flow splitter, sump, and pump box with a recirculation system was installed after it. A recirculation pump returned a high proportion of the system effluent back to the supplemental treatment tank. Two supplemental treatment tank sizes, three flowrates, and three recirculation rates were tested. Actual wastewater was dosed as brief slugs to the system in accordance with a set schedule. Several ion-exchange resins housed in a contact column were tested on the effluent for their potential to remove phosphorus. Low effluent levels of five-day biochemical oxygen demand, suspended solids, and total nitrogen were achieved and substantial phosphorous removal was also achieved using a 3780-L supplemental treatment tank, a recirculation

  1. Engineered nanoparticles in wastewater and wastewater sludge - Evidence and impacts

    International Nuclear Information System (INIS)

    Brar, Satinder K.; Verma, Mausam; Tyagi, R.D.; Surampalli, R.Y.

    2010-01-01

    Nanotechnology has widespread application in agricultural, environmental and industrial sectors ranging from fabrication of molecular assemblies to microbial array chips. Despite the booming application of nanotechnology, there have been serious implications which are coming into light in the recent years within different environmental compartments, namely air, water and soil and its likely impact on the human health. Health and environmental effects of common metals and materials are well-known, however, when the metals and materials take the form of nanoparticles - consequential hazards based on shape and size are yet to be explored. The nanoparticles released from different nanomaterials used in our household and industrial commodities find their way through waste disposal routes into the wastewater treatment facilities and end up in wastewater sludge. Further escape of these nanoparticles into the effluent will contaminate the aquatic and soil environment. Hence, an understanding of the presence, behavior and impact of these nanoparticles in wastewater and wastewater sludge is necessary and timely. Despite the lack of sufficient literature, the present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.

  2. An ecological vegetation-activated sludge process (V-ASP) for decentralized wastewater treatment: system development, treatment performance, and mathematical modeling.

    Science.gov (United States)

    Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Li, Pu; Zhao, Ke

    2016-05-01

    An environment-friendly decentralized wastewater treatment process that is comprised of activated sludge process (ASP) and wetland vegetation, named as vegetation-activated sludge process (V-ASP), was developed for decentralized wastewater treatment. The long-term experimental results evidenced that the vegetation sequencing batch reactor (V-SBR) process had consistently stable higher removal efficiencies of organic substances and nutrients from domestic wastewater compared with traditional sequencing batch reactor (SBR). The vegetation allocated into V-SBR system could not only remove nutrients through its vegetation transpiration ratio but also provide great surface area for microorganism activity enhancement. This high vegetation transpiration ratio enhanced nutrients removal effectiveness from wastewater mainly by flux enhancement, oxygen and substrate transportation acceleration, and vegetation respiration stimulation. A mathematical model based on ASM2d was successfully established by involving the specific function of vegetation to simulate system performance. The simulation results on the influence of operational parameters on V-ASP treatment effectiveness demonstrated that V-SBR had a high resistance to seasonal temperature fluctuations and influent loading shocking.

  3. Minimization of Excess Sludge in Activated Sludge Systems

    Directory of Open Access Journals (Sweden)

    Sayed Ali Reza Momeni

    2006-01-01

    Full Text Available The disposal of excess sludge from wastewater treatment plant represents a rising challenge in activated sludge processes. Hence, the minimization of excess sludge production was investigated by increasing the dissolved oxygen in aeration basin. Units of the pilot include: Primary sedimentation tank, aeration basin, secondary sedimentation tank, and return sludge tank. Volume of aeration basin is 360 l and influent flow rate is 90 L/h. Influent of pilot is taken from effluent of grit chamber of Isfahan's North Wastewater treatment plant. The experiments were done on different parts of pilot during the 5 month of study. Results show that increase of dissolved oxygen in aeration tank affect on decrease of excess sludge. Increase of dissolved oxygen from 0.5 to 4.5 mg/L resulted in 25% decrease of excess sludge. Variation of dissolved oxygen affect on settleability of sludge too. By increase of dissolved oxygen, SVI decreased and then increased. Value of 1-3 mg/L was the adequate range of dissolved oxygen by settleability of sludge and optimum range was 2-2.5 mg/L. It could be concluded by increasing of dissolved oxygen up to of 3 mg/L, sludge settleability significant decreased.

  4. Hydrodynamic cavitation as a novel approach for pretreatment of oily wastewater for anaerobic co-digestion with waste activated sludge.

    Science.gov (United States)

    Habashi, Nima; Mehrdadi, Nasser; Mennerich, Artur; Alighardashi, Abolghasem; Torabian, Ali

    2016-07-01

    Application of hydrodynamic cavitation (HC) was investigated with the objective of biogas production enhancement from co-digestion of oily wastewater (OWW) and waste activated sludge (WAS). Initially, the effect of HC on the OWW was evaluated in terms of energy consumption and turbidity increase. Then, several mixtures of OWW (with and without HC pretreatment) and WAS with the same concentration of total volatile solid were prepared as a substrate for co-digestion. Following, several batch co-digestion trials were conducted. To compare the biogas production, a number of digestion trials were also conducted with a mono substrate (OWW or WAS alone). The best operating condition of HC was achieved in the shortest retention time (7.5 min) with the application of 3mm diameter orifice and maximum pump rotational speed. Biogas production from all co-digestion reactors was higher than the WAS mono substrate reactors. Moreover, biogas production had a direct relationship with OWW ratio and no major inhibition was observed in any of the reactors. The biogas production was also enhanced by HC pretreatment and almost all of the reactors with HC pretreatment had higher reaction rates than the reactors without pretreatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Treatment of swine wastewater in continuous activated sludge systems under different dissolved oxygen conditions: Reactor operation and evaluation using modelling.

    Science.gov (United States)

    Waki, Miyoko; Yasuda, Tomoko; Fukumoto, Yasuyuki; Béline, Fabrice; Magrí, Albert

    2018-02-01

    Swine wastewater was treated in two continuously aerated activated sludge (AS) systems at high (AS1: 1.7-2.6 mg/L) and low (AS2: 0.04-0.08 mg/L) dissolved oxygen (DO), and at three temperatures (10, 20, and 30 °C). Biochemical oxygen demand (BOD) removal was >94.8%. Meanwhile, total nitrogen (N) removal was significantly higher in AS2, at 64, 89, and 88%, than in AS1, at 12, 24, and 46%, for 10, 20, and 30 °C, respectively. The experimental data were considered in a simulation study using an AS model for BOD and N removal, which also included nitrite, free ammonia, free nitrous acid, and temperature. Simulations at high-DO showed that ammonium was partly oxidized into nitrate but not removed, whereas at low-DO ammonium was removed mainly through the nitrite shortcut in simultaneous nitrification-denitrification. This study demonstrates that treatment at low-DO is an effective method for removing N, and modelling a helpful tool for its optimization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Anaerobic digestion of industrial activated aerobic sludge

    International Nuclear Information System (INIS)

    Goodloe, J.G.; Roberts, R.S.

    1990-04-01

    The Tennessee Eastman Company manufactures a variety of organic chemicals, plastics and fibers at their Kingsport Tennessee Facility. The wastewater generated during the manufacture of these compounds is currently treated using an activated sludge process. The objective of the project is to evaluate the economic potential of an anaerobic digestion process to convert industrial sludge at the Tennessee Eastman Company into biogas. The evaluation will require collection and analysis of experimental data on the anaerobic digestion of industrial sludge obtained from Kingsport. Although the experiments will be conducted using Tennessee Eastman sludge, these results should be also generally applicable to similar industrial sludge

  7. Wastewater and Sludge Reuse Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Ioannis K. Kalavrouziotis

    2016-08-01

    Full Text Available Huge quantities of treated wastewater (TMWW and biosolids (sludge are produced every day all over the world, which exert a strong pressure on the environment. An important question that is raised is “what to do with them?”.An effort is put by the scientific community to eliminate the concept of “waste” and to replace it with the concept of “recycling of resources”, by means of effective management, which does not concern only the users, but all the other groups involved in the problem, such as facility administrators, operations, politicians, scientific community and the general population. Sludge concentration data showed that there exist 516 chemicals in biosolids which create a serious health risk. It is pointed out that this risk will be greatly exacerbated by chemical toxins present in the sludge which can predispose skin to infection by pathogens. Consequently, the need for science-based policies are necessary to effectively protect public health. The risk assessment due to sludge, is difficult to evaluate of due to the large number of unknown interactions involved. People living near the sludge application sites may suffer from such abnormalities as: eye, nose, and throat irritation, gastrointestinal abnormalities, as nausea, vomiting, diarrhea, including cough, difficulty in breathing, sinus congestion, skin infection and sores. Many problems seem to be related to biosolid and wastewater application in agriculture, which should be solved. A universal one, acknowledged as an “international health crisis” is the resistance of pathogens to antibiotics and to the evolution of multidrug resistance of bacteria”. Certain anthropogenically created environments have been identified as major sources of multidrug resistance bacteria such as in water treatment plants, concentrated animal feeding operations etc. All these, and many other health problems, render the safety of sludge and biosolid and wastewater agricultural reuse, for

  8. Elevational characteristics of the archaeal community in full-scale activated sludge wastewater treatment plants at a 3,660-meter elevational scale.

    Science.gov (United States)

    Niu, Lihua; Zhang, Xue; Li, Yi; Wang, Peifang; Zhang, Wenlong; Wang, Chao; Wang, Qing

    2017-07-01

    Due to the important roles of archaea in wastewater treatment processes, archaeal communities have been studied extensively in various anaerobic reactors, but the knowledge of archaeal communities in full-scale activated sludge wastewater treatment plants (WWTPs) remains quite poor. In this study, 454-pyrosequencing was for the first time employed to investigate archaeal communities from 20 full-scale activated sludge WWTPs distributed at a 3,660-meter elevational scale in China. Results showed that archaeal communities from WWTPs were dominated by Methanosarcinales (84.6%). A core archaeal population (94.5%) composed of Methanosaeta, Methanosarcina, Methanogenium and Methanobrevibacter was shared among WWTPs. The elevational pattern of archaeal communities was observed in WWTPs, with an elevational threshold associated with archaeal community richness and structures at approximately 1,500 meters above sea level (masl). A declining trend in community richness with increasing elevation was observed at higher elevations, whereas no trend was presented at lower elevations. Spearman correlation analysis indicated that the archaeal community richness at higher elevations was associated with more environmental variables than that at lower elevations. Redundancy analysis indicated that wastewater variables were the dominant contributors to the variation of community structures at higher elevations, followed by operational variables and elevation.

  9. Characterization and distribution of esterase activity in activated sludge

    NARCIS (Netherlands)

    Boczar, BA; Forney, LJ; Begley, WM; Larson, RJ; Federle, TW

    2001-01-01

    The location and activity of esterase enzymes in activated Sludge from three Municipal wastewater treatment plants were characterized using model Substrate, and denaturing and nondenaturing polyacrylamide gel electrophoresis (PAGE) Of particulate, freeze thaw (primarily periplasmic enzymes and those

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

    Directory of Open Access Journals (Sweden)

    Dipti Prakash Mohapatra

    2011-09-01

    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.

  11. Treatment of wastewater and sludge, and decomposition of endocrine disrupting chemicals with radiation

    International Nuclear Information System (INIS)

    Kudo, Hisaaki

    2006-01-01

    This country report describes the past and current research activities in Japan on radiation treatment of wastewater and sludge carried out by early 90s, and decomposition of endocrine disrupting chemicals that is going-on. (author)

  12. 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.

    2008-01-01

    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.

  13. Fate and impact of phthalates in activated sludge treated municipal wastewater on the water bodies in the Eastern Cape, South Africa.

    Science.gov (United States)

    Salaudeen, Taofeek; Okoh, Omobola; Agunbiade, Foluso; Okoh, Anthony

    2018-07-01

    The concentration and fates of six priority phthalate esters (PAEs); dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di (2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) in wastewaters from the wastewater treatment plants (WWTPs) which adopted the activated sludge technology in the Amathole Municipality, Eastern Cape, South Africa were investigated. The six PAEs were detected in all the influents and in almost all the WWTP effluent of which DBP was the most abundant in the influent followed by DEHP. Influent concentration of DBP in the three WWTPs ranged between 2.7 and 2488 μgL -1 and the average effluent concentration was 4.90-8.88 μgL -1 . On average, the concentration of PAEs in WWTP effluents were higher than PAEs in the upstream and downstream of the discharging point suggesting PAE impact on the receiving water. The concentrations detected in the sludge of which DEHP and DBP were more pervasive ranged between 130 and 1094 μg/g dry weight. The average removal capacity; 27.3-99.5% suggested more adsorption on settling particles and sludge than biodegradation as high significant correlation was found between PAEs removal, total suspended solid and turbidity. Removal of high molecular weight and high octanol-water partition coefficient (logK ow ) PAEs through adsorption was found to be significantly high. It could be concluded that the release of PAEs into the sludge, and the amount in the final effluent which were found to exceed the acceptable levels allowed internationally, raises safety concern for both aquatic and human's health. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Characterization of functional microorganism groups and substrate in activated sludge and wastewater by AUR, NUR and OUR

    DEFF Research Database (Denmark)

    Kristensen, G. Holm; Jørgensen, P. Elberg; Henze, Mogens

    1992-01-01

    . The results indicated that influent biomass is of significance for the obtained fraction of denitrifiers to heterotrophs. For a separate nitrification stage activated sludge without denitrification a fraction of denitrifiers of 15-20% was found. The results of endogenous NUR and OUR determinations indicated...

  15. Sorption and biodegradation of selected benzotriazoles and hydroxybenzothiazole in activated sludge and estimation of their fate during wastewater treatment

    DEFF Research Database (Denmark)

    Mazioti, Aikaterini A.; Stasinakis, Athanasios S.; Gatidou, Georgia

    2015-01-01

    Biodegradation of benzotriazole (BTR), 5-chlorobenzotriazole (CBTR), xylytriazole (XTR), 4-methyl-1H-benzotriazole (4TTR), 5-methy-1H-lbenzotriazole (5TTR) and 2-hydroxybenzothiazole (OHBTH) was studied in activated sludge batch experiments under aerobic and anoxic conditions, presence of organic...

  16. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  17. Pandemic pharmaceutical dosing effects on wastewater treatment: no adaptation of activated sludge bacteria to degrade the antiviral drug oseltamivir (Tamiflu®) and loss of nutrient removal performance.

    Science.gov (United States)

    Slater, Frances R; Singer, Andrew C; Turner, Susan; Barr, Jeremy J; Bond, Philip L

    2011-02-01

    The 2009-2010 influenza pandemic saw many people treated with antivirals and antibiotics. High proportions of both classes of drugs are excreted and enter wastewater treatment plants (WWTPs) in biologically active forms. To date, there has been no study into the potential for influenza pandemic-scale pharmaceutical use to disrupt WWTP function. Furthermore, there is currently little indication as to whether WWTP microbial consortia can degrade antiviral neuraminidase inhibitors when exposed to pandemic-scale doses. In this study, we exposed an aerobic granular sludge sequencing batch reactor, operated for enhanced biological phosphorus removal (EBPR), to a simulated influenza-pandemic dosing of antibiotics and antivirals for 8 weeks. We monitored the removal of the active form of Tamiflu(®), oseltamivir carboxylate (OC), bacterial community structure, granule structure and changes in EBPR and nitrification performance. There was little removal of OC by sludge and no evidence that the activated sludge community adapted to degrade OC. There was evidence of changes to the bacterial community structure and disruption to EBPR and nitrification during and after high-OC dosing. This work highlights the potential for the antiviral contamination of receiving waters and indicates the risk of destabilizing WWTP microbial consortia as a result of high concentrations of bioactive pharmaceuticals during an influenza pandemic. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Effect of mixed liquor volatile suspended solids (MLVSS and hydraulic retention time (HRT on the performance of activated sludge process during the biotreatment of real textile wastewater

    Directory of Open Access Journals (Sweden)

    Kapil Kumar

    2014-03-01

    Full Text Available Adequate information is available on colour and organics removal in batch mode using pure microbial cultures from dye contaminated wastewater. There was a need to develop environment friendly and cost effective treatment technique for actual field conditions. Therefore, the present study was undertaken with an aim to evaluate the potential of acclimatized mixed microbial consortia for the removal of colour and organics from real textile wastewater. Experiments were performed in laboratory scale activated sludge process (ASP unit under steady state condition, varying mixed liquor volatile suspended solids (MLVSS (2500, 3500 and 5000 mg/l and hydraulic retention time (HRT (18, 24 and 36 h. The results showed that decolourization and chemical oxygen demand (COD removal increased with increase in MLVSS and HRT. At 18 h HRT, decolourization was found to be 46, 54 and 67%, which increased to 67, 75 and 90% (36 h HRT at 2500, 3500 and 5000 mg/l MLVSS, respectively. COD removal was found to be 62, 73 and 77% (at 18 h HRT which increased to 77, 85 and 91% (36 h HRT at 2000, 3500 and 5000 mg/l MLVSS, respectively. On the basis of the results obtained in this study suitable treatment techniques can be developed for the treatment of wastewater contaminated with variety of dyes in continuous mode of operation. This shall have the advantage of treatment of larger quantity of wastewater in shorter duration.

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

    Science.gov (United States)

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

    2009-11-01

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

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

    Science.gov (United States)

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

  1. Wastewater and sludge reuse in agriculture

    Science.gov (United States)

    Kalavrouziotis, Ioannis

    2016-04-01

    The reuse of Municipal wastewaters (TMWW) for irrigation of crops, and of sludge for the amendment of soils, is a multidimensional disposal practice aiming at: (i) minimizing the environmental problems by releasing the pressure exerted by these two inputs on the environment, (ii) providing the growing plants with water and nutrients and (ii) improving soil fertility and productivity, The research work conducted in our University in relation to accomplishing a safe reuse has been focused on the study of the following aspects of reuse: (i) heavy metal accumulation in soils and plants with emphasis on their edible part. This aspect has been studied by conducting a series of experiments aiming at the study of the accumulation of heavy metals in soils, and in plant roots, stalks, leaves and fruits. The conclusions drawn so far with regard to the order of accumulation of heavy metals are: Roots>leaves>stalks>fruits ( edible parts) (ii) interactions between heavy metals, plant nutrients and soil chemical and physical properties. After the examinations of hundreds of interactions, and the development of a quantification of the interactions contribution, it was found that considerable quantities of heavy metals and nutrients are contributed to the soil and to various plant parts , emphasizing the important role of the elemental interactions in plants.(iii) assessment of soil pollution with heavy metals based on pollution indices, Three pollution Indices have been established by our research team and were proposed internationally for application in actual practice for the prediction of soil pollution due to long term reuse of wastewater and sludge. These indices are as follows: (a) Elemental pollution Index (EPI), (b) Heavy Metal Load (HML), and (c) Total Concentration Factor (TCF) and (iv) construction of a computer program for the control of the reuse of TMWW and sludge, and forecasting soil pollution due to accumulation of heavy metal by means of pollution indices.

  2. Activated Sludge and Aerobic Biofilm Reactors

    OpenAIRE

    Von Sperling, Marcos

    2007-01-01

    "Activated Sludge and Aerobic Biofilm Reactors is the fifth volume in the series Biological Wastewater Treatment. The first part of the book is devoted to the activated sludge process, covering the removal of organic matter, nitrogen and phosphorus.A detailed analysis of the biological reactor (aeration tank) and the final sedimentation tanks is provided. The second part of the book covers aerobic biofilm reactors, especially trickling filters, rotating biological contractors and submerged ae...

  3. Removal of antibiotics in wastewater: Effect of hydraulic and solid retention times on the fate of tetracycline in the activated sludge process.

    Science.gov (United States)

    Kim, Sungpyo; Eichhorn, Peter; Jensen, James N; Weber, A Scott; Aga, Diana S

    2005-08-01

    A study was conducted to examine the influence of hydraulic retention time (HRT) and solid retention time (SRT) on the removal of tetracycline in the activated sludge processes. Two lab-scale sequencing batch reactors (SBRs) were operated to simulate the activated sludge process. One SBR was spiked with 250 microg/L tetracycline, while the other SBR was evaluated at tetracycline concentrations found in the influent of the wastewater treatment plant (WWTP) where the activated sludge was obtained. The concentrations of tetracyclines in the influent of the WWTP ranged from 0.1 to 0.6 microg/L. Three different operating conditions were applied during the study (phase 1-HRT: 24 h and SRT: 10 days; phase 2-HRT: 7.4 h and SRT: 10 days; and phase 3-HRT: 7.4 h and SRT: 3 days). The removal efficiency of tetracycline in phase 3 (78.4 +/- 7.1%) was significantly lower than that observed in phase 1 (86.4 +/- 8.7%) and phase 2 (85.1 +/- 5.4%) at the 95% confidence level. The reduction of SRT in phase 3 while maintaining a constant HRT decreased tetracycline removal efficiency. Sorption kinetics reached equilibrium within 24 h. Batch equilibrium experiments yielded an adsorption coefficient (Kads) of 8400 +/- 500 mL/g and a desorption coefficient (Kdes) of 22 600 +/- 2200 mL/g. No evidence of biodegradation for tetracycline was observed during the biodegradability test, and sorption was found to be the principal removal mechanism of tetracycline in activated sludge.

  4. Recovery of nitrogen and phosphorus from alkaline fermentation liquid of waste activated sludge and application of the fermentation liquid to promote biological municipal wastewater treatment.

    Science.gov (United States)

    Tong, Juan; Chen, Yinguang

    2009-07-01

    In previous publications we reported that by controlling the pH at 10.0 the accumulation of short-chain fatty acids (SCFA) during waste activated sludge (WAS) fermentation was remarkably improved [Yuan, H., Chen, Y., Zhang, H., Jiang, S., Zhou, Q., Gu, G., 2006. Improved bioproduction of short-chain fatty acids (SCFAs) from excess sludge under alkaline conditions. Environ. Sci. Technol. 40, 2025-2029], but significant ammonium nitrogen (NH(4)-N) and soluble ortho-phosphorus (SOP) were released [Chen, Y., Jiang, S., Yuan, H., Zhou, Q., Gu, G., 2007. Hydrolysis and acidification of waste activated sludge at different pHs. Water Res. 41, 683-689]. This paper investigated the simultaneous recovery of NH(4)-N and SOP from WAS alkaline fermentation liquid and the application of the fermentation liquid as an additional carbon source for municipal wastewater biological nitrogen and phosphorus removal. The central composite design (CCD) of the response surface methodology (RSM) was employed to optimize and model the simultaneous NH(4)-N and SOP recovery from WAS alkaline fermentation liquid. Under the optimum conditions, the predicted and experimental recovery efficiency was respectively 73.4 and 75.7% with NH(4)-N, and 82.0 and 83.2% with SOP, which suggested that the developed models described the experiments well. After NH(4)-N and SOP recovery, the alkaline fermentation liquid was added to municipal wastewater, and the influence of volume ratio of fermentation liquid to municipal wastewater (FL/MW) on biological nitrogen and phosphorus removal was investigated. The addition of fermentation liquid didn't significantly affect nitrification. Both SOP and total nitrogen (TN) removal were increased with fermentation liquid, but there was no significant increase at FL/MW greater than 1/35. Compared to the blank test, the removal efficiency of SOP and TN at FL/MW=1/35 was improved from 44.0 to 92.9%, and 63.3 to 83.2%, respectively. The enhancement of phosphorus and nitrogen

  5. The Microbial Database for Danish wastewater treatment plants with nutrient removal (MiDas-DK) - a tool for understanding activated sludge population dynamics and community stability.

    Science.gov (United States)

    Mielczarek, A T; Saunders, A M; Larsen, P; Albertsen, M; Stevenson, M; Nielsen, J L; Nielsen, P H

    2013-01-01

    Since 2006 more than 50 Danish full-scale wastewater treatment plants with nutrient removal have been investigated in a project called 'The Microbial Database for Danish Activated Sludge Wastewater Treatment Plants with Nutrient Removal (MiDas-DK)'. Comprehensive sets of samples have been collected, analyzed and associated with extensive operational data from the plants. The community composition was analyzed by quantitative fluorescence in situ hybridization (FISH) supported by 16S rRNA amplicon sequencing and deep metagenomics. MiDas-DK has been a powerful tool to study the complex activated sludge ecosystems, and, besides many scientific articles on fundamental issues on mixed communities encompassing nitrifiers, denitrifiers, bacteria involved in P-removal, hydrolysis, fermentation, and foaming, the project has provided results that can be used to optimize the operation of full-scale plants and carry out trouble-shooting. A core microbial community has been defined comprising the majority of microorganisms present in the plants. Time series have been established, providing an overview of temporal variations in the different plants. Interestingly, although most microorganisms were present in all plants, there seemed to be plant-specific factors that controlled the population composition thereby keeping it unique in each plant over time. Statistical analyses of FISH and operational data revealed some correlations, but less than expected. MiDas-DK (www.midasdk.dk) will continue over the next years and we hope the approach can inspire others to make similar projects in other parts of the world to get a more comprehensive understanding of microbial communities in wastewater engineering.

  6. Application of waterworks sludge in wastewater treatment plants

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  7. Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process.

    Science.gov (United States)

    Yamaguchi, T; Yao, Y; Kihara, Y

    2006-01-01

    A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.

  8. Sludge Reduction by Lumbriculus Variegatus in Ahvaz Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Tim Hendrickx

    2012-08-01

    Full Text Available 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 extensivehealth hazards. Application of aquatic worm is an approach to decrease the amount of biological waste sludge produced in wastewater treatment plants. In the present research reduction of the amount of waste sludge from Ahvaz wastewater treatment plant was studied with the aquatic worm Lumbriculus variegatus in a reactor concept. The sludge reduction in the reactor with worm was compared to sludge reduction in a blank reactor (without worm.The effects of changes in dissolved oxygen (DO concentration up to 3 mg/L (run 1 and up to 6 mg/L (run 2 were studied in the worm and blank reactors. No meaningful relationship was found between DO concentration and the rate of total suspended solids reduction. Theaverage sludge reductions were obtained as 33% (run 2 and 32% (run 1 in worm reactor,and 16% (run 1 and 12% (run 2 in the blank reactor. These results showed that the worm reactors may reduce the waste sludge between 2 and 2.75 times higher than in the blankconditions. The obtained results showed that the worm reactor has a high potential for use in large-scale sludge processing.

  9. Processed wastewater sludge for improvement of mechanical properties of concretes

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Diaz, Carlos, E-mail: cbd0044@yahoo.com [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Martinez-Barrera, Gonzalo [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Carretera Toluca-Atlacomulco, Km.12, San Cayetano C.P. 50200, Toluca, Edo. de Mexico (Mexico); Gencel, Osman [Civil Engineering Department, Faculty of Engineering, Bartin University, 74100 Bartin (Turkey); Bernal-Martinez, Lina A. [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico - Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de Mexico (Mexico); Brostow, Witold [Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science and Engineering and Center for Advanced Research and Technology (CART), University of North Texas, 1150 Union Circle 305310, Denton, TX 76203-5017 (United States)

    2011-08-15

    Highlights: {yields} Electrochemical methods produce less amount of residual sludge as compared with chemical procedures. {yields} Wastewater sludge contains a large amount of water. {yields} The residual sludge is used to prepare cylinder specimen concrete. {yields} There are improvements in the elastic modulus of the concrete when is prepared with residual sludge. - Abstract: Two problems are addressed simultaneously. One is the utilisation of sludge from the treatment of wastewater. The other is the modification of the mechanical properties of concrete. The sludge was subjected to two series of treatments. In one series, coagulants were used, including ferrous sulphate, aluminium sulphate or aluminium polyhydroxychloride. In the other series, an electrochemical treatment was applied with several starting values of pH. Then, concretes consisting of a cement matrix, silica sand, marble and one of the sludges were developed. Specimens without sludge were prepared for comparison. Curing times and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and static and dynamic elastic moduli were determined. Diagrams of the compressive strength and compressive strain at the yield point as a function of time passed through the minima as a function of time for concretes containing sludge; therefore, the presence of sludge has beneficial effects on the long term properties. Some morphological changes caused by the presence of sludge are seen in scanning electron microscopy. A way of utilising sludge is thus provided together with a way to improve the compressive strain at yield point of concrete.

  10. Effects of reduced return activated sludge flows and volume on anaerobic zone performance for a septic wastewater biological phosphorus removal system.

    Science.gov (United States)

    Magro, Daniel; Elias, Steven L; Randall, Andrew Amis

    2005-01-01

    Enhanced biological phosphorous removal (EBPR) performance was found to be adequate with reduced return-activated sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller-than-typical anaerobic zone volume (1.08 hours hydraulic retention time [HRT]). Three identical parallel biological nutrient removal pilot plants were fed with strong, highly fermented (160 mg/L volatile fatty acids [VFAs]), domestic and industrial wastewater from a full-scale wastewater treatment facility. The pilot plants were operated at 100, 50, 40, and 25% RAS (percent of available RAS) flows to the anaerobic tank, with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours) and increased hydraulic loading (35% increase) were examined. The study was divided into four phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusion was that returning part of the RAS to the anaerobic zone did not decrease EBPR performance; instead, it changed the location of phosphorous release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic phosphorus release and increased anoxic phosphorus release (or decreased anoxic phosphorus uptake). Equally important is that, with VFA-rich influent wastewater, excessive anaerobic volume was shown to hurt overall phosphorus removal, even when it resulted in increased anaerobic phosphorus release.

  11. Isolation of a naphthalene-degrading strain from activated sludge and bioaugmentation with it in a MBR treating coal gasification wastewater.

    Science.gov (United States)

    Xu, Peng; Ma, Wencheng; Han, Hongjun; Jia, Shengyong; Hou, Baolin

    2015-03-01

    A highly effective naphthalene-degrading bacterial strain was isolated from acclimated activated sludge from a coal gasification wastewater plant, and identified as a Streptomyces sp., designated as strain QWE-35. The optimal pH and temperature for naphthalene degradation were 7.0 and 35°C. The presence of additional glucose and methanol significantly increased the degradation efficiency of naphthalene. The strain showed tolerance to the toxicity of naphthalene at a concentration as great as 200 mg/L. The Andrews mode could be fitted to the degradation kinetics data well over a wide range of initial naphthalene concentrations (10-200 mg/L), with kinetic values q max = 0.84 h(-1), K s = 40.39 mg/L, and K i = 193.76 mg/L. Metabolic intermediates were identified by gas chromatography and mass spectrometry, allowing a new degradation pathway for naphthalene to be proposed for the first time. Strain QWE-35 was added into a membrane bioreactor (MBR) to enhance the treatment of real coal gasification wastewater. The results showed that the removal of chemical oxygen demand and total nitrogen were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of naphthalene was obtained in the bioaugmented reactor. The findings suggest a potential bioremediation role of Streptomyces sp. QWE-35 in the removal of naphthalene from wastewaters.

  12. Microbiology of the active sludge as a system to improve the effluents quality in the wastewater treatment plants

    International Nuclear Information System (INIS)

    Rodriguez, E.; Reina, E.; Fernandez, N.

    2009-01-01

    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

  13. Wastewater sludge treatment at selected wastewater treatment plants of the region Banska Bystrica

    International Nuclear Information System (INIS)

    Samesova, D.; Mitterpach, J.; Martinkova, A.

    2014-01-01

    The management of sewage sludges in water treatment plants of Banska Bystrica region. The paper deals with the problems of sewage sludge in wastewater treatment plants, its origin and possibilities how to use it in accordance with the current legislation of the Slovak Republic. We described radioactive pollution of sewage sludges. The paper consists of review of sludge production and its usage in the Slovak Republic and in selected states of the European Union. The paper deals with the sludge treatment in selected wastewater treatment plants in Banska Bystrica region in the context of biogas production and its usage by the help of the electricity and heat production. (authors)

  14. Activated sludge model No. 3

    DEFF Research Database (Denmark)

    Gujer, W.; Henze, M.; Mino, T.

    1999-01-01

    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 of org...

  15. Removal of Antibiotics in Biological Wastewater Treatment Systems—A Critical Assessment Using the Activated Sludge Modeling Framework for Xenobiotics (ASM-X)

    DEFF Research Database (Denmark)

    Polesel, Fabio; Andersen, Henrik Rasmus; Trapp, Stefan

    2016-01-01

    Many scientific studies present removal efficiencies for pharmaceuticals in laboratory-, pilot-, and full-scale wastewater treatment plants, based on observations that may be impacted by theoretical and methodological approaches used. In this Critical Review, we evaluated factors influencing...... observed removal efficiencies of three antibiotics (sulfamethoxazole, ciprofloxacin, tetracycline) in pilot- and full-scale biological treatment systems. Factors assessed include (i) retransformation to parent pharmaceuticals from e.g., conjugated metabolites and analogues, (ii) solid retention time (SRT......), (iii) fractions sorbed onto solids, and (iv) dynamics in influent and effluent loading. A recently developed methodology was used, relying on the comparison of removal efficiency predictions (obtained with the Activated Sludge Model for Xenobiotics (ASM-X)) with representative measured data from...

  16. Production of extracellular polymeric substances (EPS) by Serratia sp.1 using wastewater sludge as raw material and flocculation activity of the EPS produced.

    Science.gov (United States)

    Bezawada, J; Hoang, N V; More, T T; Yan, S; Tyagi, N; Tyagi, R D; Surampalli, R Y

    2013-10-15

    Growth profile and extracellular polymeric substances (EPS) production of Serratia sp.1 was studied in shake flask fermentation for 72 h using wastewater sludge as raw material. Maximum cell concentration of 6.7 × 10(9) cfu/mL was obtained at 48 h fermentation time. EPS dry weight, flocculation activity and dewaterability of different EPS (tightly bound or TB-EPS, loosely bound or LB-EPS and broth-EPS or B-EPS) were also measured. The highest concentration of LB-EPS (2.45 g/L) and TB-EPS (0.99 g/L) were attained at 48 h of fermentation. Maximum flocculation activity and dewaterability (ΔCST) of TB-EPS (76.4%, 14.5s and 76.5%, 15.5s), LB-EPS (67.8%, 8.1s and 64.7%, 7.6s) and broth EPS (61%, 6.1s and 70.4%, 6.8s) were obtained at 36 and 48 h of growth. Higher flocculation activity and dewaterability were achieved with TB-EPS than with the two other EPS. Characterization of TB-EPS and LB-EPS was done in terms of their protein and carbohydrate content. Protein content was much higher in TB-EPS where as carbohydrate content was only slightly higher in TB-EPS than LB-EPS. Morphology of the Serratia strain after fermentation in sludge and TSB was observed under a scanning electron microscope and the cell size was found to be bigger in the sludge medium than the TSB medium. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Model evaluation of temperature dependency for carbon and nitrogen removal in a full-scale activated sludge plant treating leather-tanning wastewater.

    Science.gov (United States)

    Görgün, Erdem; Insel, Güçlü; Artan, Nazik; Orhon, Derin

    2007-05-01

    Organic carbon and nitrogen removal performance of a full-scale activated sludge plant treating pre-settled leather tanning wastewater was evaluated under dynamic process temperatures. Emphasis was placed upon observed nitrogen removal depicting a highly variable magnitude with changing process temperatures. As the plant was not specifically designed for this purpose, observed nitrogen removal could be largely attributed to simultaneous nitrification and denitrification presumably occurring at increased process temperatures (T>25 degrees C) and resulting low dissolved oxygen levels (DO<0.5 mgO2/L). Model evaluation using long-term data revealed that the yearly performance of activated sludge reactor could be successfully calibrated by means of temperature dependent parameters associated with nitrification, hydrolysis, ammonification and endogenous decay parameters. In this context, the Arrhenius coefficients of (i) for the maximum autotrophic growth rate, [image omitted]A, (ii) maximum hydrolysis rate, khs and (iii) endogenous heterotrophic decay rate, bH were found to be 1.045, 1.070 and 1.035, respectively. The ammonification rate (ka) defining the degradation of soluble organic nitrogen could not be characterized however via an Arrhenius-type equation.

  18. Gravitational sedimentation of flocculated waste activated sludge.

    Science.gov (United States)

    Chu, C P; Lee, D J; Tay, J H

    2003-01-01

    The sedimentation characteristics of flocculated wastewater sludge have not been satisfactorily explored using the non-destructive techniques, partially owing to the rather low solid content (ca. 1-2%) commonly noted in the biological sediments. This paper investigated, for the first time, the spatial-temporal gravitational settling characteristics of original and polyelectrolyte flocculated waste activated sludge using Computerized Axial Tomography Scanner. The waste activated sludge possessed a distinct settling characteristic from the kaolin slurries. The waste activated sludges settled more slowly and reached a lower solid fraction in the final sediment than the latter. Flocculation markedly enhanced the settleability of both sludges. Although the maximum achievable solid contents for the kaolin slurries were reduced, flocculation had little effects on the activated sludge. The purely plastic rheological model by Buscall and White (J Chem Soc Faraday Trans 1(83) (1987) 873) interpreted the consolidating sediment data, while the purely elastic model by Tiller and Leu (J. Chin. Inst. Chem. Eng. 11 (1980) 61) described the final equilibrated sediment. Flocculation produced lower yield stress during transient settling, thereby resulting in the more easily consolidated sludge than the original sample. Meanwhile, the flocculated activated sludge was stiffer in the final sediment than in the original sample. The data reported herein are valuable to the theories development for clarifier design and operation.

  19. Fate of nanosilver in wastewater treatment plants and their impact on nitrification activity in sewage sludge; Verhalten von Nanosilber in Klaeranlagen und dessen Einfluss auf die Nitrifikationsleistung in Belebtschlamm

    Energy Technology Data Exchange (ETDEWEB)

    Burkhardt, Michael [Eawag: Das Wasserforschungs-Institut des ETH-Bereichs, Duebendorf (Switzerland); HSR Hochschule fuer Technik, Rapperswil (CH). Inst. fuer Umwelt- und Verfahrenstechnik (UMTEC); Zuleeg, Steffen [Eawag: Das Wasserforschungs-Institut des ETH-Bereichs, Duebendorf (Switzerland); KUSTER + HAGER Ingenieurbuero AG, St. Gallen (Switzerland); Kaegi, Ralf; Sinnet, Brian; Eugster, Jakob; Boller, Markus; Siegrist, Hansruedi [Eawag: Das Wasserforschungs-Institut des ETH-Bereichs, Duebendorf (Switzerland)

    2010-10-15

    The application of nanosilver is increasing. Knowledge on the fate and behavior of nanosilver in wastewater and wastewater treatment plants is scarce. Studies under real world conditions are completely lacking. We studied (1) the impact of nanosilver on the nitrification of sewage sludge, (2) quantified the mass flow of nanosilver in a pilot-plant, and (3) verified the mass balance in a full-scale municipal wastewater treatment plant where nanosilver is introduced to the municipal plant by an indirect discharger. The addition of four different nanosilver additives on ammonia oxidation in activated sludge has been studied in batch-reactors at two concentrations (1, 100 mg/L Ag) with two exposure times (2 h, 6 days). The pilot-plant treating 70 population equivalents of domestic wastewater is operated with a 12 day sludge age. Nanosilver was applied to the activated sludge tank within two sludge ages. The silver concentrations were measured in sludge and effluent samples during dosing and the following two sludge ages. The adsorption and speciation of silver particles has been analyzed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Influent, effluent and sludge were sampled on a full-scale plant (60 000 equivalent inhabitants) and analyzed for silver. Silver nitrate, metallic nanosilver, nano-scaled silver chloride and microcomposite silver did not show any effect on ammonia oxidation after the addition of 1 mg/L Ag to the activated sludge (corresponding to 250 mg Ag per kg solids). In contrast, 100 mg/L Ag inhibited the nitrification process by 100 % after the addition of silver nitrate and 20-30 % after addition of colloidal polymer-coated nanosilver. A complete mass balance of the pilot-plant, a steady-state system with known fluxes, demonstrates significant enrichment of silver in the sewage sludge (96 %) after the addition of silver chloride to the plant and small losses of silver into the secondary effluent (4

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

    Science.gov (United States)

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

    2009-01-01

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

  1. Removal of the Inert Organic Fraction of Municipal Wastewater Using the Integrated Activated Sludge/Trickling Filter System

    Directory of Open Access Journals (Sweden)

    mehraban sadeghi

    2015-01-01

    Full Text Available The discharge of phenol and chlorinated compounds, fatty acids, tannin, lignin, and their by-products into receptive waters poses serious hazards for the aquatic life. In this study, the efficiency of a tow-step process of activated sludge-trickling filter (AS/TF in the removal of inert chemical materials that defy conventional treatment processes was investigated. For this purpose, an integrated activated sludge process (industrial scale was used sequentially with a trickling filter (pilot scale. Inside a tank with an effective volume of 6.87 m3 was installed 5.78 m3 of polypropylene 2HX media with a specific area of 240 m2/m3. The hydraulic loading rate (HLR of the trickling filter during the startup period (90 days was 3.6 m3/h which was raised to 3.6-6 m3/h in the operation period (120 days, with the best effluent quality achieved at HLR=5.4 m3/h. For the purposes of the experiments in this study, four reactors, each 1256 cm3 in volume, were fed the WWTP effluent and concurrently a glucose substrate containing a COD content equal to that fed to the four reactors was fed into two identical reactors; all the reactors were subsequently run for 480 h in aerobic conditions. Nutrients, pH, and DO (as environmental control indicators as well as soluble and total COD were measured twice daily. The effluent values of soluble inert materials (SI, total soluble COD (STO, degradable suspended materials (XSO, degradable COD (CSO, refractory suspended materials (XI, and degradable soluble materials (SSO for AS were calculated as 40, 227, 94, 281, 251, and 187, respectively, while the same parameters for the AS/TF were 20, 227, 104, 311, 241, and 207 mg/l, respectively. The results showed that the activated sludge process when combined with the trickling filter has a twofold capability, compared to when used alone, in removing inert COD. It was also shown that treatment levels in conventional WWTPs can be improved by integrating conventional treatment

  2. Inactivation of poliovirus by gamma irradiation of wastewater sludges

    International Nuclear Information System (INIS)

    Kaupert, Norma L.; Burgi, Elsa; Scolaro, L.

    1999-01-01

    The effect of gamma radiation on poliovirus infectivity seeded in sludge samples was investigated in order to determine the radiation dose required to inactivate 90% of viral infectivity (D 10 ). Sludges were obtained from anaerobic pretreated sewages produced by San Felipe, a wastewater treatment facility located at the Tucuman province, Argentina. A D 10 of 3.34 kGy was determined for poliovirus type III, Sabin strain, suspended in sludge samples. This value dropped to 1.92 kGy when the virus was suspended in water. A virucidal effect associated to sludges was also demonstrated. These results will be of interest when considering the dose of gamma radiation to be applied to wastewater sludges in order to preserve the environment from viral contamination. (author)

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

    International Nuclear Information System (INIS)

    Escolà Casas, Mònica; Bester, Kai

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Escolà Casas, Mònica; Bester, Kai, E-mail: kb@dmu.dk

    2015-02-15

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

  5. Effect of Ionic Strength on Settling of Activated Sludge

    OpenAIRE

    M Ahmadi Moghadam, M Soheili, MM Esfahani

    2005-01-01

    Structural properties of activated sludge flocs were found to be sensitive to small changes in ionic strength. This study investigates the effect of ionic strength on settling of activated sludge. Samples were taken from activated sludge process of Ghazvin Sasan soft drink wastewater treatment plant, then treated with different ionic strengths of KCl and CaCl2 solution, after that the turbidity of supernatant was measured. The results indicated that low ionic strength resulted in a steeper sl...

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

    Science.gov (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.

  7. Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus

    2012-01-01

    Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct...... and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast...

  8. Bacteriology of activated sludge

    NARCIS (Netherlands)

    Gils, van H.W.

    1964-01-01

    The bacteriology and biochemistry of activated sludge grown in domestic waste water or fed with synthetic media were studied. The nature of the flocs was investigated by determining morphological and physiological characteristics of many strains isolated.

    Predominant bacteria were

  9. Vermistabilization of Municipal Wastewater Sludge with Eisenia fetida

    Directory of Open Access Journals (Sweden)

    A Parvaresh, H Movahedian, L Hamidian

    2004-10-01

    Full Text Available Sludges are stabilized to reduce pathogens, eliminate offensive odors and inhibit, reduce or eliminate the potential for putrification. In this study, stabilization of municipal wastewater sludge with and without earthworms (Eisenia fetida was tested in a pilot study. The earthworms were fed at the optimum level of 0.75 kg-feed/kg-worm/day. Decomposition and stabilization of wastewater sludge occurred both in the presence and in the absence of earthworms during 9 weeks but the process was accelerated in their presence. Phosphorus content increased in the sludge with earthworms but decreased in it without them. Nitrogen content in the resulting vermicompost showed no difference with its quantity in the original substrate while it increased in the control treatment.

  10. Activated Sludge Rheology

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Horn, Willi; Helmus, Frank

    2013-01-01

    Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtr...... rheological measurements. Moreover, the rheological models are not very trustworthy and remain very “black box”. More insight in the physical background needs 30 to be gained. A model-based approach with dedicated experimental data collection is the key to address this.......Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling......, leading to varying results and conclusions. In this paper, a vast amount of papers are critically reviewed with respect to this and important flaws are highlighted with respect to rheometer choice, rheometer settings and measurement protocol. The obtained rheograms from experimental efforts have...

  11. Environmental sustainability of wastewater sludge treatments

    DEFF Research Database (Denmark)

    Boyer-Souchet, Florence; Larsen, Henrik Fred

    treatment for municipal waste water. A special focus area in Neptune is sludge handling because the sludge amount is expected to increase due to advanced waste water treatment. The main sludge processing methods assessed in Neptune can be divided into two categories: disintegration processes before...... anaerobic digestion (thermal hydrolysis and ultrasound disintegration) and inertisation processes performed at high temperatures (incineration, pyrolysis, gasification, wet oxidation) but they all aim at volume reduction and removal of biodegradable compounds before safe sludge disposal or reuse of its...... 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...

  12. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla, Dept. de Ingenieria Quimica y Ambiental, Sevilla (Spain); Gutierrez, J.C. [Universidad Pablo de Olavide, Dept. de Ciencias Ambientales, Sevilla (Spain); Lebrato, J. [Universidad de Sevilla, Grupo Tratamiento de Aguas Residuales, Sevilla (Spain)

    2005-07-01

    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (Author)

  13. Economic assessment of biodiesel production from wastewater sludge.

    Science.gov (United States)

    Chen, Jiaxin; Tyagi, Rajeshwar Dayal; Li, Ji; Zhang, Xiaolei; Drogui, Patrick; Sun, Feiyun

    2018-04-01

    Currently, there are mainly two pathways of the biodiesel production from wastewater sludge including 1) directly extracting the lipid in sludge and then converting the lipid to biodiesel through trans-esterification, and 2) employing sludge as medium to cultivate oleaginous microorganism to accumulate lipid and then transferring the lipid to biodiesel. So far, the study was still in research stage and its cost feasibility was not yet investigated. In this study, biodiesel production from wastewater sludge was designed and the cost was estimated with SuperPro Designer. With consideration of converting the lipid in raw sludge to biodiesel, the unit production cost was 0.67 US $/kg biodiesel (0.59 US $/L biodiesel). When the sludge was used as medium to grow oleaginous microorganism to accumulate lipid for producing biodiesel, the unit production cost was 1.08 US $/kg biodiesel (0.94 US $/L biodiesel). The study showed that sludge has great potential in biodiesel production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Impact of sludge properties on solid-liquid separation of activated sludge

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard

    2016-01-01

    Solid-liquid separation of activated sludge is important both directly after the biological treatment of wastewater and for sludge dewatering. The separation of solid from the treated wastewater can be done by clarifiers (conventional plants) or membrane (MBR). Further, part of the sludge is taken...... out from the proces and usually dewatered before further handling. The separation process is costly. Moreover, the separation process depends on the composition and the properties of the sludge. The best separation is obtained for sludge that contains strong, compact flocs without single cells...... and dissolved extracellular polymeric substances (EPS). Polyvalent ions improve the floc strangth and improve the separation whereas monovalent ions (e.g. from road salt, sea water intrusion and industry) reduces impair the separation. Further high pH impairs the separation process due to floc disintegration...

  15. The application of different techniques to determine activated sludge ...

    African Journals Online (AJOL)

    The application of different techniques to determine activated sludge kinetic parameters in a food industry wastewater. ... method) and a respirometric technique based on oxygen consumption measurements, were used to compare microbial parameters using a wastewater model system of a potato processing plant.

  16. Wastewater Sludge Stabilization Using Lime A Case Study of West Ahwaz Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Mehdi Farzadkia

    2009-01-01

    Full Text Available Lime stabilization is a chemical method used for wastewater sludge stabilization. It is capable of decreasing large quantities of pathogens and of preventing microbial degradation of sludge organic materials. The main objective of the present experimental research was to investigate stabilization of the sludge from west Ahwaz wastewater treatment plant by lime addition and to control if the microbial quality of this sludge conforms to the USEPA standards for sludge reuse and safe disposal. The study was carried out on a pilot scale in 5 stages over a period of 12 months (July 2005 to June 2006 at west Ahwaz wastewater treatment plant laboratory using raw sludge. For the purposes of this study, a 30-liter reactor was commissioned and loaded with sludge and appropriate quantities of hydrated lime were added based on the solid waste percent. The parameters used to determine stabilization efficiency were pH, Total Coliform, Fecal Coliform, and parasite eggs. The results showed that lime addition at a ratio of 265g Ca(OH2/kg. ds was the optimum level for sludge stabilization in westAhwazwastewater treatment plant, which is acceptable from both economic and technical viewpoints. The method is capable of achieving class B but never satisfied class A of USEPA standards.

  17. Removal of Antibiotics in Biological Wastewater Treatment Systems-A Critical Assessment Using the Activated Sludge Modeling Framework for Xenobiotics (ASM-X).

    Science.gov (United States)

    Polesel, Fabio; Andersen, Henrik R; Trapp, Stefan; Plósz, Benedek Gy

    2016-10-04

    Many scientific studies present removal efficiencies for pharmaceuticals in laboratory-, pilot-, and full-scale wastewater treatment plants, based on observations that may be impacted by theoretical and methodological approaches used. In this Critical Review, we evaluated factors influencing observed removal efficiencies of three antibiotics (sulfamethoxazole, ciprofloxacin, tetracycline) in pilot- and full-scale biological treatment systems. Factors assessed include (i) retransformation to parent pharmaceuticals from e.g., conjugated metabolites and analogues, (ii) solid retention time (SRT), (iii) fractions sorbed onto solids, and (iv) dynamics in influent and effluent loading. A recently developed methodology was used, relying on the comparison of removal efficiency predictions (obtained with the Activated Sludge Model for Xenobiotics (ASM-X)) with representative measured data from literature. By applying this methodology, we demonstrated that (a) the elimination of sulfamethoxazole may be significantly underestimated when not considering retransformation from conjugated metabolites, depending on the type (urban or hospital) and size of upstream catchments; (b) operation at extended SRT may enhance antibiotic removal, as shown for sulfamethoxazole; (c) not accounting for fractions sorbed in influent and effluent solids may cause slight underestimation of ciprofloxacin removal efficiency. Using tetracycline as example substance, we ultimately evaluated implications of effluent dynamics and retransformation on environmental exposure and risk prediction.

  18. Improving biogas production from continuous co-digestion of oily wastewater and waste-activated sludge by hydrodynamic cavitation pre-treatment.

    Science.gov (United States)

    Habashi, Nima; Alighardashi, Abolghasem; Mennerich, Artur; Mehrdadi, Nasser; Torabian, Ali

    2018-04-01

    Hydrodynamic cavitation (HC) was evaluated as a pretreatment for synthetic oily wastewater (OWW) to be co-digested with waste-activated sludge (WAS). The main objective of the present research was the enhancement of biogas production by the application of HC pretreatment. HC was applied to the OWW, and the OWW and WAS were added to a 50 L continuous digestion reactor. As a control system, an identical digestion reactor was set up for co-digestion of the WAS and the OWW without pretreatment. The reactors were initially filled with inoculum and the hydraulic retention time (HRT) was set to 22 d. The HRT was gradually reduced to 19, 16, and finally 13 d, but the substrate quality was kept constant. The loading rate, accordingly, increased from 0.86 to 1.46 g TVS/(L d). The biogas volume was recorded online and its quality was analyzed regularly. The HC improved biogas production up to 43% at 22 d of HRT. Reducing the HRT decreased biogas production from the main reactor while that of the control reactor was more or less constant. HC also increased the biogas methane content; the methane concentration of the main reactor was about 3% higher than the methane concentration of the control reactor. The main reactor experienced no clogging or accumulation of fatty materials.

  19. Improved compaction of dried tannery wastewater sludge.

    Science.gov (United States)

    Della Zassa, M; Zerlottin, M; Refosco, D; Santomaso, A C; Canu, P

    2015-12-01

    We quantitatively studied the advantages of improving the compaction of a powder waste by several techniques, including its pelletization. The goal is increasing the mass storage capacity in a given storage volume, and reducing the permeability of air and moisture, that may trigger exothermic spontaneous reactions in organic waste, particularly as powders. The study is based on dried sludges from a wastewater treatment, mainly from tanneries, but the indications are valid and useful for any waste in the form of powder, suitable to pelletization. Measurements of bulk density have been carried out at the industrial and laboratory scale, using different packing procedures, amenable to industrial processes. Waste as powder, pellets and their mixtures have been considered. The bulk density of waste as powder increases from 0.64 t/m(3) (simply poured) to 0.74 t/m(3) (tapped) and finally to 0.82 t/m(3) by a suitable, yet simple, packing procedure that we called dispersion filling, with a net gain of 28% in the compaction by simply modifying the collection procedure. Pelletization increases compaction by definition, but the packing of pellets is relatively coarse. Some increase in bulk density of pellets can be achieved by tapping; vibration and dispersion filling are not efficient with pellets. Mixtures of powder and pellets is the optimal packing policy. The best compaction result was achieved by controlled vibration of a 30/70 wt% mixture of powders and pellets, leading to a final bulk density of 1t/m(3), i.e. an improvement of compaction by more than 54% with respect to simply poured powders, but also larger than 35% compared to just pellets. That means increasing the mass storage capacity by a factor of 1.56. Interestingly, vibration can be the most or the least effective procedure to improve compaction of mixtures, depending on characteristics of vibration. The optimal packing (30/70 wt% powders/pellets) proved to effectively mitigate the onset of smouldering

  20. Influence of nanoparticles on the polymer-conditioned dewatering of wastewater sludges.

    Science.gov (United States)

    Boyle, N J; Evans, G M

    2013-01-01

    The effect of using small-scale, high surface area, nanoparticles to supplement polymer-conditioned wastewater sludge dewatering was investigated. Aerobically digested sludge and waste activated sludge sourced from the Hunter Valley, NSW, Australia, were tested with titanium dioxide nanoparticles. The sludge samples were dosed with the nanoparticles in an attempt to adsorb a component of the charged biopolymer surfactants present naturally in sludge. The sludge was conditioned with a cationic polymer. The dewatering characteristics were assessed by measuring the specific resistance to filtration through a modified time-to-filter testing apparatus. The solids content of the dosed samples was determined by a mass balance and compared to the original solids content in the activated sludge. Test results indicated that nanoparticle addition modified the structure of the sludge and provided benefits in terms of the dewatering rate. The samples dosed with nanoparticles exhibited faster water removal, indicating a more permeable filter cake and hence more permeable sludge. A concentration of 2-4% nanoparticles was required to achieve a noticeable benefit. As a comparison, the sludge samples were also tested with a larger particle size, powdered activated carbon (PAC). It was found that the PAC did provide some minor benefits to sludge dewatering but was outperformed by the nanoparticles. The solids content of the final sludge was increased by a maximum of up to 0.6%. The impact of the order sequence of particles and polymer was also investigated. It was found that nanoparticles added before polymer addition provided the best dewatering performance. This outcome was consistent with current theories and previous research through the literature. An economic analysis was undertaken to confirm the viability of the technology for implementation at a full-scale plant. It was found that, currently, this technology is unlikely to be favourable unless the nanoparticles can be

  1. Hydrolysis rates of domestic wastewater sludge using biochemical ...

    African Journals Online (AJOL)

    Domestic wastewater treatment can be improved by reducing energy consumption and increasing carbon recovery, which can be achieved using anaerobic digestion of sludge with methane recovery at ambient temperature. Hydrolysis can be a limiting step in anaerobic digestion, and characterisation of hydrolysis rates ...

  2. Harvesting biogas from wastewater sludge and food waste

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. Dissinfection of municipal sludge and wastewater by energized electrons

    International Nuclear Information System (INIS)

    Trump, J.G.; Wright, K.A.; Sinskey, A.J.; Shah, D.N.; Fernald, R.

    1979-01-01

    Laboratory studies at M.I.T. and high flow rate studies at the M.D.C. Deer Island Wastewater Treatment Plant in Boston have shown the practicality and cost effectiveness of disinfecting liquid municipal sludges by injecting energized electrons. A dosage of 400 Kilorads (4 Kilograys) reduces gram-negative bacteria, including coliforms, fecal coliforms, salmonellae and shigellae, in primary raw or anaerobically digested sludges to undetectable levels. Enteric viruses are reduced by one to two orders of magnitude. This treatment also destroys parasite eggs or renders them non-infectious. Model system studies indicate that trace toxic compounds such as PCBs in water are degraded. The estimated cost of sludge disinfection by electron treatment is about $0.80 per liquid tonne for modular systems of 650 liquid tonnes per day capacity. About 6 Kilowatt-hours of input electric power per tonne is required. The temperature rise of the disinfected watery sludge is about 2 0 C. Electron disinfection combined with subsurface soil injection offers an environmentally attractive, energy-efficient, and economic two -step process for land disposal of municipal sludges with water conservation and soil improvement benefits. Combined with widely-distributed ocean feeding, electron disinfection of the municipal sludge of coastal communities offers a safe marine nutrient for increasing fish population in treated ocean areas. The electron disinfection of effluent wastewater, in lieu of chlorination, is a future application which avoids the production of potentially toxic chlorinated hydrocarbons. (Author) [pt

  4. Biosynthesis of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) by bacterial community from propylene oxide saponification wastewater residual sludge.

    Science.gov (United States)

    Wang, Yiwei; Zhu, Ying; Gu, Pengfei; Li, Yumei; Fan, Xiangyu; Song, Dongxue; Ji, Yan; Li, Qiang

    2017-05-01

    The saponification wastewater from the process of propylene oxide (PO) production is contaminated with high chemical oxygen demand (COD) and chlorine contents. Although the activated sludge process could treat the PO saponification wastewater effectively, the residual sludge was difficult to be disposed properly. In this research, microbes in PO saponification wastewater residual sludge were acclimated to produce poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from volatile fatty acids. Through Miseq Illumina highthroughput sequencing, the bacterial community discrepancy between the original and the acclimated sludge samples were analyzed. The proportions of Bacillus, Acinetobacter, Brevundimonas and Pseudomonas, the potential PHBV-producers in the residual sludge, were all obviously increased. In the batch fermentation, the production of PHBV could achieve 4.262g/L at 300min, with the content increased from 0.04% to 23.67% of mixed liquor suspended solid (MLSS) in the acclimated sludge, and the COD of the PO saponification wastewater was also decreased in the fermentation. This work would provide an effective solution for the utilization of PO saponification wastewater residual sludge. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Enhancement of activated sludge disintegration and dewaterability by Fenton process

    Science.gov (United States)

    Heng, G. C.; Isa, M. H.

    2016-06-01

    Municipal and industrial wastewater treatment plants produce large amounts of sludge. This excess sludge is an inevitable drawback inherent to the activated sludge process. In this study, the waste activated sludge was obtained from the campus wastewater treatment plant at Universiti Teknologi PETRONAS (UTP), Malaysia. Fenton pretreatment was optimized by using the response surface methodology (RSM) to study the effects of three operating conditions including the dosage of H2O2 (g H2O2/kg TS), the molar ratio of H2O2/Fe2+ and reaction time. The optimum operating variables to achieve MLVSS removal 65%, CST reduction 28%, sCOD 11000 mg/L and EPS 500 mg/L were: 1000 g H2O2/kg TS, H2O2/Fe2+ molar ratio 70 and reaction time 45 min. Fenton process was proved to be able to enhance the sludge disintegration and dewaterability.

  6. Performance indicators and indices of sludge management in urban wastewater treatment plants.

    Science.gov (United States)

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

    2016-12-15

    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.

  7. Evaluation of the Hospital Wastewater Activated Sludge Extended Aeration System in the Removal of Estrogenic Compounds (Case Study: Khuzestan Hospitals

    Directory of Open Access Journals (Sweden)

    A. Takdastan

    2016-02-01

    Full Text Available Background and Objective: Estrogen is a steroid hormone that is in the water and cause risks for aquatic organisms, especially fish is. Estrogenic hormones naturally (caused by endocrine or artificial (due to hormonal contraceptives such as birth control pills to sewage and hospital to find. This study aimed to determine the amount of estrogen in the sewage and Golestan and Abuzar hospital in Ahvaz were studied. Material and Methods: Sampling was done by tracking estrogen in the aquatic environment. 56 samples 4 months in different parts of the Golestan and Abuzar hospital wastewater treatment plant in Ahvaz were taken. Sample a little electro luminescence (ECL were analyzed by laboratory Iranian city of Ahvaz. In this study, different forms of estrogen (estrone, 17-beta-estradiol, estriol, 17-alpha-ethinyl estradiol has been studied as estrogen. Results: Mean hormone found in raw wastewater to the Golestan hospital wastewater treatment plant effluent from the treatment plant hormone 69.08 ng/l and 7.28 ng/l mean. Mean testosterone in Ahvaz Abuzar hospital treatment input 70.61 ng/l and 18.94 ng/l is refinery output. According to the results of high impact biological treatment is the removal of estrogenic compounds. Conclusion: Secondary treatment of sewage is effective in reducing hormones that can do this at this stage of the biological treatment effect.

  8. Predicting the degradability of waste activated sludge.

    Science.gov (United States)

    Jones, Richard; Parker, Wayne; Zhu, Henry; Houweling, Dwight; Murthy, Sudhir

    2009-08-01

    The objective of this study was to identify methods for estimating anaerobic digestibility of waste activated sludge (WAS). The WAS streams were generated in three sequencing batch reactors (SBRs) treating municipal wastewater. The wastewater and WAS properties were initially determined through simulation of SBR operation with BioWin (EnviroSim Associates Ltd., Flamborough, Ontario, Canada). Samples of WAS from the SBRs were subsequently characterized through respirometry and batch anaerobic digestion. Respirometry was an effective tool for characterizing the active fraction of WAS and could be a suitable technique for determining sludge composition for input to anaerobic models. Anaerobic digestion of the WAS revealed decreasing methane production and lower chemical oxygen demand removals as the SRT of the sludge increased. BioWin was capable of accurately describing the digestion of the WAS samples for typical digester SRTs. For extended digestion times (i.e., greater than 30 days), some degradation of the endogenous decay products was assumed to achieve accurate simulations for all sludge SRTs.

  9. Dynamic modeling of sludge compaction and consolidation processes in wastewater secondary settling tanks.

    Science.gov (United States)

    Abusam, A; Keesman, K J

    2009-01-01

    The double exponential settling model is the widely accepted model for wastewater secondary settling tanks. However, this model does not estimate accurately solids concentrations in the settler underflow stream, mainly because sludge compression and consolidation processes are not considered. In activated sludge systems, accurate estimation of the solids in the underflow stream will facilitate the calibration process and can lead to correct estimates of particularly kinetic parameters related to biomass growth. Using principles of compaction and consolidation, as in soil mechanics, a dynamic model of the sludge consolidation processes taking place in the secondary settling tanks is developed and incorporated to the commonly used double exponential settling model. The modified double exponential model is calibrated and validated using data obtained from a full-scale wastewater treatment plant. Good agreement between predicted and measured data confirmed the validity of the modified model.

  10. A computational technique for turbulent flow of wastewater sludge.

    Science.gov (United States)

    Bechtel, Tom B

    2005-01-01

    A computational fluid dynamics (CFD) technique applied to the turbulent flow of wastewater sludge in horizontal, smooth-wall, circular pipes is presented. The technique uses the Crank-Nicolson finite difference method in conjunction with the variable secant method, an algorithm for determining the pressure gradient of the flow. A simple algebraic turbulence model is used. A Bingham-plastic rheological model is used to describe the shear stress/shear rate relationship for the wastewater sludge. The method computes velocity gradient and head loss, given a fixed volumetric flow, pipe size, and solids concentration. Solids concentrations ranging from 3 to 10% (by weight) and nominal pipe sizes from 0.15 m (6 in.) to 0.36 m (14 in.) are studied. Comparison of the CFD results for water to established values serves to validate the numerical method. The head loss results are presented in terms of a head loss ratio, R(hl), which is the ratio of sludge head loss to water head loss. An empirical equation relating R(hl) to pipe velocity and solids concentration, derived from the results of the CFD calculations, is presented. The results are compared with published values of Rhl for solids concentrations of 3 and 6%. A new expression for the Fanning friction factor for wastewater sludge flow is also presented.

  11. Electron beam treatment of wastewaters and sludges

    International Nuclear Information System (INIS)

    Osborn, D.W.

    1980-01-01

    Various procedures for decreasing the health risks associated with the disposal of sewage sludges are discussed including land storage, thermophilic digestion, autothermal aerobic digestion, the Porteus Process, the Zimpro Process, incineration, pyrolysis, thermal pasteurisation, composting, lime utilisation, flash drying and radiation techniques. A fully automated sludge irradiation facility at Geiselbullach near Munich and an electron accelerator experimental plant near Boston are described. Advantages and disadvantages are given for both processes. Costs of electron radiation treatment of sewage sludges (a slurry containing 5 per cent solids) for a city the size of Johannesburg is estimated to be in the order of R900 000 per year at a dose rate of 4 000 Gy, which would produce a product of reasonable hygienic quality but not necessarily meet the criteria laid down by local authority medical officers at all times. In order to reduce costs it would be necessary to have a readily available market to dispose of disinfected material

  12. Electron beam treatment of wastewaters and sludges

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, D W [City Health Dept., Johannesburg (South Africa)

    1980-12-01

    Various procedures for decreasing the health risks associated with the disposal of sewage sludges are discussed including land storage, thermophilic digestion, autothermal aerobic digestion, the Porteus Process, the Zimpro Process, incineration, pyrolysis, thermal pasteurisation, composting, lime utilisation, flash drying and radiation techniques. A fully automated sludge irradiation facility at Geiselbullach near Munich and an electron accelerator experimental plant near Boston are described. Advantages and disadvantages are given for both processes. Costs of electron radiation treatment of sewage sludges (a slurry containing 5 per cent solids) for a city the size of Johannesburg is estimated to be in the order of R900,000 per year at a dose rate of 4,000 Gy, which would produce a product of reasonable hygienic quality but not necessarily meet the criteria laid down by local authority medical officers at all times. In order to reduce costs it would be necessary to have a readily available market to dispose of disinfected material.

  13. Ultrasonic reduction of excess sludge from the activated sludge system

    International Nuclear Information System (INIS)

    Zhang Guangming; Zhang Panyue; Yang Jinmei; Chen Yanming

    2007-01-01

    Sludge treatment has long become the most challenging problem in wastewater treatment plants. Previous studies showed that ozone or chlorine effectively liquefies sludge into substrates for bio-degradation in the aeration tank, and thus reduces the excess sludge. This paper employs ultrasound to reduce the excess sludge from the sequential batch reactor (SBR) system. Partial sludge was disintegrated into dissolved substrates by ultrasound in an external sono-tank and was then returned to the SBR for bio-degradation. The results showed that ultrasound (25 kHz) effectively liquefied the sludge. The most effective conditions for sludge reduction were as following: sludge sonication ratio of 3/14, ultrasound intensity of 120 kW/kgDS, and sonication duration of 15 min. The amount of excess sludge was reduced by 91.1% to 17.8 mg/(L d); the organic content and settleability of sludge in the SBR were not impacted. The chemical oxygen demand (COD) removal efficiency was 81.1%, the total nitrogen (TN) removal efficiency was 17-66%, and high phosphorus concentration in the effluent was observed

  14. The sustainable utilization of malting industry wastewater biological treatment sludge

    Science.gov (United States)

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

    2018-01-01

    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.

  15. Stabilization of heavy metals in fired clay brick incorporated with wastewater treatment plant sludge: Leaching analysis

    Science.gov (United States)

    Kadir, A. A.; Hassan, M. I. H.; Salim, N. S. A.; Sarani, N. A.; Ahmad, S.; Rahmat, N. A. I.

    2018-04-01

    Wastewater treatment sludge or known as sewage sludge is regarded as the residue and produced by the sedimentation of the suspended solid during treatment at the wastewater treatment plant. As such, this sludge was gained from the separation process of the liquids and solids. This sludge wastes has becomes national issues in recent years due to the increasing amount caused by population and industrialization growth in Malaysia. This research was conducted to fully utilize the sludge that rich in dangerous heavy metals and at the same time act as low cost alternative materials in brick manufacturing. The investigation includes determination of heavy metal concentration and chemical composition of the sludge, physical and mechanical properties. Wastewater treatment sludge samples were collected from wastewater treatment plant located in Johor, Malaysia. X-Ray Fluorescence was conducted to determine the heavy metals concentration of wastewater treatment sludge. Different percentage of sludges which are 0%, 1%, 5%, 10%, and 20%, has been incorporated into fired clay brick. The leachability of heavy metals in fired clay brick that incorporated with sludge were determined by using Toxicity Characteristic Leaching Procedure (TCLP) and Synthetic Precipitation Leachability Procedure (SPLP) that has been analyzed by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results show a possibility to stabilize the heavy metals in fired clay brick incorporated with wastewater treatment sludge. 20% of the sludge incorporated into the brick is the most suitable for building materials as it leached less heavy metals concentration and complying with USEPA standard.

  16. Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering.

    Science.gov (United States)

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

    2010-04-01

    Wastewater treatment plants often face the problems of sludge settling mainly due to sludge bulking. Generally, synthetic organic polymer and/or inorganic coagulants (ferric chloride, alum and quick lime) are used for sludge settling. These chemicals are very expensive and further pollute the environment. Whereas, the bioflocculants are environment friendly and may be used to flocculate the sludge. Extracellular polymeric substances (EPS) produced by sludge microorganisms play a definite role in sludge flocculation. In this study, 25 EPS producing strains were isolated from municipal wastewater treatment plant. Microorganisms were selected based on EPS production properties on solid agar medium. Three types of EPS (slime, capsular and bacterial broth mixture of both slime and capsular) were harvested and their characteristics were studied. EPS concentration (dry weight), viscosity and their charge (using a Zetaphoremeter) were also measured. Bioflocculability of obtained EPS was evaluated by measuring the kaolin clay flocculation activity. Six bacterial strains (BS2, BS8, BS9, BS11, BS15 and BS25) were selected based on the kaolin clay flocculation. The slime EPS was better for bioflocculation than capsular EPS and bacterial broth. Therefore, extracted slime EPS (partially purified) from six bacterial strains was studied in terms of sludge settling [sludge volume index (SVI)] and dewatering [capillary suction time (CST)]. Biopolymers produced by individual strains substantially improved dewaterability. The extracted slime EPS from six different strains were partially characterized. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  17. 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)

    2007-09-15

    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)

  18. Diurnal variations in the occurrence and the fate of hormones and antibiotics in activated sludge wastewater treatment in Oslo, Norway

    International Nuclear Information System (INIS)

    Plosz, Benedek Gy.; Leknes, Henriette; Liltved, Helge; Thomas, Kevin V.

    2010-01-01

    We present an assessment of the dynamics in the influent concentration of hormones (estrone, estriol) and antibiotics (trimethoprim, sulfamethoxazole, tetracycline, ciprofloxacin) in the liquid phase including the efficiency of biological municipal wastewater treatment. The concentration of estradiol, 17-α-ethinylestradiol, doxycycline, oxytetracycline, demeclocycline, chlortetracycline, cefuroxime, cyclophosphamide, and ifosfamide were below the limit of detection in all of the sewage samples collected within this study. Two different types of diurnal variation pattern were identified in the influent mass loads of selected antibiotics and hormones that effectively correlate with daily drug administration patterns and with the expected maximum human hormone release, respectively. The occurrence of natural hormones and antimicrobials, administered every 12 hours, shows a daily trend of decreasing contaminant mass load, having the maximum values in the morning hours. The occurrence of antibiotics, typically administered every 8 hours, indicates a daily peak value in samples collected under the highest hydraulic loading. The efficiency of biological removal of both hormones and antibiotics is shown to be limited. Compared to the values obtained in the influent samples, increased concentrations are observed in the biologically treated effluent for trimethoprim, sulfamethoxazole and ciprofloxacin, mainly as a result of deconjugation processes. Ciprofloxacin is shown as the predominant antimicrobial compound in the effluent, and it is present at quantities approximately 10 fold greater than the total mass of the other of the compounds due to poor removal efficiency and alternating solid-liquid partitioning behaviour. Our results suggest that, to increase the micro-pollutant removal and the chemical dosing efficiency in enhanced tertiary treatment, significant benefits can be derived from the optimisation of reactor design and the development of control schemes that

  19. Diurnal variations in the occurrence and the fate of hormones and antibiotics in activated sludge wastewater treatment in Oslo, Norway

    Energy Technology Data Exchange (ETDEWEB)

    Plosz, Benedek Gy., E-mail: benedek.plosz@niva.no [Norwegian Institute for Water Research, NIVA, Gaustadalleen 21, NO-0349, Oslo (Norway); Leknes, Henriette [Norwegian Institute for Air Research NILU, 2027 Kjeller (Norway); Liltved, Helge; Thomas, Kevin V. [Norwegian Institute for Water Research, NIVA, Gaustadalleen 21, NO-0349, Oslo (Norway)

    2010-03-15

    We present an assessment of the dynamics in the influent concentration of hormones (estrone, estriol) and antibiotics (trimethoprim, sulfamethoxazole, tetracycline, ciprofloxacin) in the liquid phase including the efficiency of biological municipal wastewater treatment. The concentration of estradiol, 17-{alpha}-ethinylestradiol, doxycycline, oxytetracycline, demeclocycline, chlortetracycline, cefuroxime, cyclophosphamide, and ifosfamide were below the limit of detection in all of the sewage samples collected within this study. Two different types of diurnal variation pattern were identified in the influent mass loads of selected antibiotics and hormones that effectively correlate with daily drug administration patterns and with the expected maximum human hormone release, respectively. The occurrence of natural hormones and antimicrobials, administered every 12 hours, shows a daily trend of decreasing contaminant mass load, having the maximum values in the morning hours. The occurrence of antibiotics, typically administered every 8 hours, indicates a daily peak value in samples collected under the highest hydraulic loading. The efficiency of biological removal of both hormones and antibiotics is shown to be limited. Compared to the values obtained in the influent samples, increased concentrations are observed in the biologically treated effluent for trimethoprim, sulfamethoxazole and ciprofloxacin, mainly as a result of deconjugation processes. Ciprofloxacin is shown as the predominant antimicrobial compound in the effluent, and it is present at quantities approximately 10 fold greater than the total mass of the other of the compounds due to poor removal efficiency and alternating solid-liquid partitioning behaviour. Our results suggest that, to increase the micro-pollutant removal and the chemical dosing efficiency in enhanced tertiary treatment, significant benefits can be derived from the optimisation of reactor design and the development of control schemes that

  20. Fungal treatment: a prospective process for eco-friendly bioremediation of wastewater sludge

    International Nuclear Information System (INIS)

    Molla, A. H.; Fakhru'l-Razi, A.

    2009-01-01

    None of the conventional techniques is safe and environmental friendly for wastewaters/sludge disposal. A sustainable, safe and environmental friendly biological technique is a great apprehension to the relevant scientists. Since the fungal treatment was exercised to evaluate its potentially for sustainable bioseparation and bioremediation of wastewater. Bioseparation and bioremediation of wastewater sludge by fungal inoculation implied the decreasing of bio solids, total suspended solids (TSS), turbidity, chemical oxygen demand (COD) and specific resistance to filtration (SRF) of wastewater. (Author)

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

    Science.gov (United States)

    Mrowiec, Bozena

    2014-01-01

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

  2. SBR treatment of tank truck cleaning wastewater: sludge characteristics, chemical and ecotoxicological effluent quality.

    Science.gov (United States)

    Caluwé, Michel; Dobbeleers, Thomas; Daens, Dominique; Geuens, Luc; Blust, Ronny; Dries, Jan

    2017-08-02

    A lab-scale activated sludge sequencing batch reactor (SBR) was used to treat tank truck cleaning (TTC) wastewater with different operational strategies (identified as different stages). The first stage was an adaptation period for the seed sludge that originated from a continuous fed industrial plant treating TTC wastewater. The first stage was followed by a dynamic reactor operation based on the oxygen uptake rate (OUR). Thirdly, dynamic SBR control based on OUR treated a daily changing influent. Lastly, the reactor was operated with a gradually shortened fixed cycle. During operation, sludge settling evolved from nearly no settling to good settling sludge in 16 days. The sludge volume index improved from 200 to 70 mL gMLSS -1 in 16 days and remained stable during the whole reactor operation. The average soluble chemical oxygen demand (sCOD) removal varied from 87.0% to 91.3% in the different stages while significant differences in the food to mass ratio were observed, varying from 0.11 (stage I) to 0.37 kgCOD.(kgMLVSS day) -1 (stage III). Effluent toxicity measurements were performed with Aliivibrio fischeri, Daphnia magna and Pseudokirchneriella subcapitata. Low sensitivity of Aliivibrio was observed. A few samples were acutely toxic for Daphnia; 50% of the tested effluent samples showed an inhibition of 100% for Pseudokirchneriella.

  3. Adsorption of Phthalates on Municipal Activated Sludge

    Directory of Open Access Journals (Sweden)

    Hongbo Wang

    2017-01-01

    Full Text Available Phthalates (PAEs are commonly detected in discharge of municipal wastewater treatment plants. This study investigated the removal of six typical PAEs with activated sludge and the results revealed that concentrations of aqueous PAEs decreased rapidly during the beginning 15 min and reached equilibrium within 2 hours due to the adsorption of activated sludge. The process followed first-order kinetic equation, except for dioctyl phthalate (DOP. The factors influencing the adsorption were also evaluated and it was found that higher initial concentrations of PAEs enhanced the removal but affected little the adsorption equilibrium time. The adsorption of PAEs favored lower operating temperature (the optimum temperature was approximately 25°C in this research, which could be an exothermic process. Additionally, lower aqueous pH could also benefit the adsorption.

  4. Pseudopedobacter beijingensis gen. nov., sp. nov., isolated from coking wastewater activated sludge, and reclassification of Pedobacter saltans as Pseudopedobacter saltans comb. nov.

    Science.gov (United States)

    Cao, Junwei; Lai, Qiliang; Li, Guizhen; Shao, Zongze

    2014-06-01

    A taxonomic study was carried out on strain GCS-AE-31(T), which was isolated from a phenol-degrading consortium, enriched from coking wastewater activated sludge of the Beijing Shougang Company Limited during the screening of phenol-degrading bacteria. Cells of strain GCS-AE-31(T) were Gram-stain-negative, short rods, motile by gliding, oxidase- and catalase-positive. Growth was observed at salinities of 0-3% and at temperatures of 10-37 °C. On the basis of 16S rRNA gene sequence similarity, strain GCS-AE-31(T) was most closely related to Pedobacter saltans LMG 10337(T) (96.17%), but it showed low similarity to all other species of the genus Pedobacter (89.28-92.45%). It also showed low 16S rRNA gene similarity to all other species of the family Sphingobacteriaceae (87.25-92.45%) examined. The dominant fatty acids were iso-C(15 : 0), summed feature 3 (C(16 : 1)ω7c/C(16 : 1)ω6c), anteiso-C(15 : 0) and iso-C(17 : 0) 3-OH. The menaquinones were MK-7 (95.5%) and MK-6 (4.5%). The polar lipids were phosphatidylethanolamine, three aminolipids and three unknown phospholipids. Sphingolipid was present. The G+C content of the chromosomal DNA was 36.2 mol%. According to its phylogenetic position and phenotypic traits, the novel strain could not be assigned to the genus Pedobacter; it should be classified as representing a novel species of a novel genus in the family Sphingobacteriaceae, for which the name Pseudopedobacter beijingensis gen. nov., sp. nov. is proposed (type strain GCS-AE-31(T) = MCCC 1A01299(T) = CGMCC 1.12329(T) = LMG 27180(T)). The misclassified species Pedobacter saltans is transferred to the novel genus as Pseudopedobacter saltans comb. nov. (type strain LMG 10337(T) = MCCC 1A06472(T) = DSM 12145(T) = CCUG 39354(T) = CIP 105500(T) = JCM 21818(T) = NBRC 100064(T)). © 2014 IUMS.

  5. Impact of accelerated electrons on activating process and foaming potential of sludge

    International Nuclear Information System (INIS)

    Cuba, V.; Pospisil, M.; Mucka, V.; Silber, R.; Jenicek, P.; Dohanyos, M.; Zabranska, J.

    2002-01-01

    Complete text of publication follows. Presently, anaerobic and/or aerobic biological treatment is the cheapest and the most effective method of wastewater and sludge processing. However, due to some non-biodegradable substances present in wastewater and also due to limited capacity of wastewater treatment plants, it is necessary to find effective processes, that would be complementary to existing sludge treatment methods. Beside chemical and physical processes, radiation technology seems to offer improvement of effectivity of biological treatment. The paper describes possibilities of irradiation in activating process. Activated sludge can be affected in all its parameters, including physico chemical properties, such as sedimentation rate, or resulting volume of sludge. For the purpose of this research, laboratory experimental reactors simulating activating process were operated. According to previous results, accelerated electrons were used for irradiation, for e-beam seems to be more expedient than gamma irradiation. Reactor with irradiated sludge has been compared with the one without irradiation. It is shown, that pre-irradiation of sludge can positively affect following process of activation. Beside the activating process, another goal has been pursued. Radiation can strongly affect sludge foaming potential. Biological foaming caused by surfactant microorganisms, represents quite serious problem in many wastewater treatment plants, especially in digesters. It was proved that after irradiation foaming potential of sludge decreases. Pre-irradiation of activated sludge with relatively low doses also results in reduction of number of pathogenic microorganisms, presented in sludge

  6. Biothane process. Methane-producing treatment of wastewaters in a granular sludge bed

    Energy Technology Data Exchange (ETDEWEB)

    Boulenger, P; Vesprille, B

    1982-01-01

    The Biothane-UASB (upflow anaerobic sludge blanket) process, an anaerobic fermentation system with 2 granular sludge beds, effectively treats wastewaters from cheese and starch manufacture and is suitable for other industrial effluents, such as sugar beet alcohol distillation wastewaters and biosynthesis wases.

  7. The nitrite-oxidizing community in activated sludge from a municipal wastewater treatment plant determined by fatty acid methyl ester-stable isotope probing.

    Science.gov (United States)

    Kruse, Myriam; Zumbrägel, Sabine; Bakker, Evert; Spieck, Eva; Eggers, Till; Lipski, André

    2013-10-01

    Metabolically-active autotrophic nitrite oxidizers from activated sludge were labeled with (13)C-bicarbonate under exposure to different temperatures and nitrite concentrations. The labeled samples were characterized by FAME-SIP (fatty acid methyl ester-stable isotope probing). The compound cis-11-palmitoleic acid, which is the major lipid of the most abundant nitrite oxidizer in activated sludge, Candidatus Nitrospira defluvii, showed (13)C-incorporation in all samples exposed to 3 mM nitrite. Subsequently, the lipid cis-7-palmitoleic acid was labeled, and it indicated the activity of a nitrite oxidizer that was different from the known Nitrospira taxa in activated sludge. The highest incorporation of cis-7-palmitoleic acid label was found after incubation with a nitrite concentration of 0.3 mM at 17 and 22°C. While activity of Nitrobacter populations could not be detected by the FAME-SIP approach, an unknown nitrite oxidizer with the major lipid cis-9 isomer of palmitoleic acid exhibited (13)C-incorporation at 28°C with 30 mM nitrite. These results indicated flexibility of nitrite-oxidizing guilds in a complex community responding to different conditions. Labeled lipids so far not described for activated sludge-associated nitrifiers indicated the presence of unknown nitrite oxidizers in this habitat. The FAME-SIP-based information can be used to define appropriate conditions for the enrichment of nitrite-oxidizing guilds from complex samples. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Recovery of polyhydroxyalkanoates from municipal secondary wastewater sludge.

    Science.gov (United States)

    Kumar, Manish; Ghosh, Pooja; Khosla, Khushboo; Thakur, Indu Shekhar

    2018-05-01

    In the current study, the feasibility of utilizing municipal secondary wastewater sludge for Polyhydroxyalkanoate (PHA) extraction was improved by optimization of various parameters (temperature, duration and concentration of sludge solids). Optimized process parameters resulted in PHA recovery of 0.605 g, significantly higher than un-optimized conditions. The characterization of PHA was carried out by GC-MS, FT-IR and NMR ( 1 H and 13 C) spectroscopy. The PHA profile was found to be dominated by mcl PHA (58%) along with other diverse PHA. The results of the present study show rich diversity of PHA extracted from a raw material which is readily available at minimal cost. In conclusion, exploring the potential of wastes for production of bioplastics not only reduces the cost of bioplastic production, but also provides a sustainable means for waste management. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Use of Natural Zeolite to Upgrade Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Hanife Büyükgüngör

    2003-01-01

    Full Text Available The objective of this study was to achieve better efficiency of phosphorus removal in an enhanced biological phosphorus removal process by upgrading the system with different amounts of natural zeolite addition. The system performance for synthetic wastewater containing different carbon sources applied at different initial concentrations of phosphorus, as well as for municipal wastewater, was investigated. Natural zeolite addition in the aerobic phase of the anaerobic/aerobic bioaugmented activated sludge system contributed to a significant improvement of phosphorus removal in systems with synthetic wastewater and fresh municipal wastewater. Improvement of phosphorus removal with regard to the control reactors was higher with the addition of 15 than with 5 g/L of natural zeolite. In reactors with natural zeolite addition with regard to the control reactors significantly decreased chemical oxygen demand, ammonium and nitrate, while higher increment and better-activated sludge settling were achieved, without changes in the pH-values of the medium. It was shown that the natural zeolite particles are suitable support material for the phosphate-accumulating bacteria Acinetobacter calcoaceticus (DSM 1532, which were adsorbed on the particle surface, resulting in increased biological activity of the system. The process of phosphorus removal in a system with bioaugmented activated sludge and natural zeolite addition consisted of: metabolic activity of activated sludge, phosphorus uptake by phosphate-accumulating bacteria adsorbed on the natural zeolite particles and suspended in solution, and phosphorus adsorption on the natural zeolite particles.

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

    Science.gov (United States)

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

    2013-01-01

    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.

  11. Radioactive and hazardous wastewater treatment and sludge stabilization by filtration

    International Nuclear Information System (INIS)

    Martin, H.L.; Pickett, J.B.; Langton, C.A.

    1991-01-01

    Concentrated effluents from batch discharges of spent process solutions are mixed with filter cake from treatment of the dilute effluents and stored in a large tank at the optimum high pH for hydroxide precipitation of heavy metals. Supernate is decanted from the storage tanks and mixed with the dilute effluents before treatment. A filtration and stabilization process has been developed to treat and stored sludge as well as the concentrated wastewater slurry as it is generated. A 94% waste volume reduction over conventional technology can be achieved. Furthermore, leachate from the solidified waste filter cake meets the EPA land disposal restrictions

  12. Catalytic pyrolysis of olive mill wastewater sludge

    Science.gov (United States)

    Abdellaoui, Hamza

    From 2008 to 2013, an average of 2,821.4 kilotons/year of olive oil were produced around the world. The waste product of the olive mill industry consists of solid residue (pomace) and wastewater (OMW). Annually, around 30 million m3 of OMW are produced in the Mediterranean area, 700,000 m3 year?1 in Tunisia alone. OMW is an aqueous effluent characterized by an offensive smell and high organic matter content, including high molecular weight phenolic compounds and long-chain fatty acids. These compounds are highly toxic to micro-organisms and plants, which makes the OMW a serious threat to the environment if not managed properly. The OMW is disposed of in open air evaporation ponds. After evaporation of most of the water, OMWS is left in the bottom of the ponds. In this thesis, the effort has been made to evaluate the catalytic pyrolysis process as a technology to valorize the OMWS. The first section of this research showed that 41.12 wt. % of the OMWS is mostly lipids, which are a good source of energy. The second section proved that catalytic pyrolysis of the OMWS over red mud and HZSM-5 can produce green diesel, and 450 °C is the optimal reaction temperature to maximize the organic yields. The last section revealed that the HSF was behind the good fuel-like properties of the OMWS catalytic oils, whereas the SR hindered the bio-oil yields and quality.

  13. Performance of a continuously operated flocculent sludge UASB reactor with slaughterhouse wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, S.; Zeeuw, W. de

    1988-01-01

    This investigation was carried out to assess the performance of a continuously operated, one-stage, flocculent sludge upflow anaerobic sludge blanket (UASB) reactor treating slaughterhouse wastewater at a process temperature of 30/sup 0/C. The results indicate that the type of substrate ingredients, coarse suspended solids, colloidal and soluble compounds in the wastewater, affect the performance of the reactor because of different mechanisms involved in their removal and their subsequent conversion into methane. Two different mechanisms are distinguished. An entrapment mechanism prevails for the elimination of coarse suspended solids while an adsorption mechanism is involved in the removal of the colloidal and soluble fractions of the wastewater. The results obtained lead to the conclusion that the system can satisfactorily handle organic space loads up to 5 kg COD m/sup -3/ day/sup -1/ at 30/sup 0/C. The data indicate, however, that continuing heavy accumulation of substrate components in the reactor is detrimental to the stability of the anaerobic treatment process as the accumulation can lead to sludge flotation and consequently to a complete loss of the active biomass from the reactor.

  14. 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.

  15. Batch system for study of Cr(VI) Bio sorption by dried waste activated sludge

    International Nuclear Information System (INIS)

    Farzadkia, M.; Gholami, M.; Darvishi Cheshmeh Soltani, R.; Yaghmaeian, K.; Shams Khorramabadi, G.

    2009-01-01

    Activated sludge from wastewater treatment systems contains both bacteria and protozoa. The cell wall of bacteria essentially consists of various compounds, such as carboxyl, acidic polysaccharides,lipids, amino acids and other components. (Author)

  16. Comparison between thermo balance and classic gravimetric method for determination of suspended solids in sludge from wastewater treatment plant

    International Nuclear Information System (INIS)

    Bruzzone, E.

    2009-01-01

    In this paper two methods for determination of suspended solids in sludge from wastewater treatment plants (activated, thickened and dry, in a range from 0.1 to 20-25%) are compared. Results are similar from statistic point of view between classic gravimetric method and thermo balance method. However the later seems better for its rapid and easy execution. [it

  17. Electron beam processing programme: Wastewater and sludge treatment in Brazil

    International Nuclear Information System (INIS)

    Sampa, M.H.O.; Rela, P.R.; Duarte, C.L.; Borrely, S.I.; Vieira, J.M.

    1998-01-01

    The Institute for Energetic and Nuclear Research, working on environmental applications, has an extensive research programme using high energy electron beam in treating industrial wastewater and sludge. The experiments are being conducted in a pilot plant using an industrial electron beam 1.5MeV, 25mA, where the streams are presented to the scanned electron beam in counter flow. This pilot plant is designed to process approximately 3.0m 3 /h with an average dose 5kGy and the absorbed dose measurement is performed continuously by calorimetric system in real time. Combined biological and radiation treatment of domestic sewage and sludge were carried out to investigate disinfestation and removal of organic matter. The experiments showed that total and fecal coliforms were decreased by about 5 logs cycles with a 3.0kGy radiation dose in raw sewage and biological effluents, respectively. Concerning the industrial wastewater in the first stage of the programme, the irradiation was conducted using batch systems with samples originating from a Governmental Wastewater Treatment Plant. The data showed a significant color reduction effect when delivered dose was increased, and the opposite was noted for turbidity and total suspended solids. Other experiments were focused to process real industrial effluents from one of the most important chemical and pharmaceutical industries in Brazil. A special transport truck was used to transfer the liquid waste from the Industry to the Electron Beam Pilot Plant. Large quantities of liquid waste were irradiated with and without air addition with the doses from 2kGy to 20kGy. Such experiences performed in association with the Industry demonstrated that this technology has a great potential to be transferred and to contribute with a permanent cleanup alternative for hazardous wastes

  18. Adverse effects of erythromycin on the structure and chemistry of activated sludge

    International Nuclear Information System (INIS)

    Louvet, J.N.; Giammarino, C.; Potier, O.; Pons, M.N.

    2010-01-01

    This study examines the effects of erythromycin on activated sludge from two French urban wastewater treatment plants (WWTPs). Wastewater spiked with 10 mg/L erythromycin inhibited the specific evolution rate of chemical oxygen demand (COD) by 79% (standard deviation 34%) and the specific N-NH 4 + evolution rate by 41% (standard deviation 25%). A temporary increase in COD and tryptophan-like fluorescence, as well as a decrease in suspended solids, were observed in reactors with wastewater containing erythromycin. The destruction of activated sludge flocs was monitored by automated image analysis. The effect of erythromycin on nitrification was variable depending on the sludge origin. Erythromycin inhibited the specific nitrification rate in sludge from one WWTP, but increased the nitrification rate at the other facility. - Erythromycin toxicity on activated sludge is expected to reduce pollution removal.

  19. Characterization of Industrial Wastewater Sludge in Oman from Three Different Regions and Recommendations for Alternate Reuse Applications.

    Science.gov (United States)

    Baawain, Mahad S; Al-Jabri, Mohsin; Choudri, B S

    2015-11-01

    Domestic and industrial wastewaters are mostly treated by biological process such as activated sludge, aerobic pond, and anaerobic treatment. This study focuses on characterizing the quality of sewage sludge in the Sultanate of Oman chosen from three industrial sewage treatment plants (STPs): Rusayl Industrial Estate (RSL.IE); Sohar Industrial Estate (SIE); and Raysut Industrial Estate (RIE). Samples of recycled activated sludge (RAS) and wasted activated sludge (WAS) were collected over a period of 12 months across above mentioned STPs. Parameters analyzed are electrical conductivity (EC), potential of hydrogen (pH), cations, anions and volatile content (VC). The obtained values for pH and EC were low for both RAS and WAS samples, except EC values of RIE that was more than 1000 μS/cm. The range of VC percentages in RAS and WAS samples were 44 to 86% and 41 to 77%, respectively. The measured values for chloride, sulfate, nitrate and phosphate were higher than the other anions. The average values of the cations in RAS and WAS samples were within the Omani Standards, suitable for the re-use of sludge in agriculture except for Cd in RSL.IE. The study recommends that a regular maintenance should be performed at the studied STPs to prevent any accumulation of some harmful substances, which may affect the sludge quality, and the sludge drying beds should be large enough to handle the produced sludge for better management.

  20. Radionuclide X-ray fluorescence determination of Mn, Fe, Cu, Zn and Pb in wastewaters and sludges from wastewater treatment plants in Bratislava (SR)

    International Nuclear Information System (INIS)

    Harangozo, M.; Toelgyessy, J.

    1997-01-01

    Radiometric X-ray fluorescence analysis was used for the determination of Mn, Fe, Cu, Zn and Pb in wastewater and sludges from three wastewater treatment plants in Bratislava (SR). Metals were determined in wastewaters after preconcentration by 8-hydroxyquinoline and in sludges by drying and pressing to pellets. 238 Pu and 109 Cd was used for excitation of fluorescence radiation. (author)

  1. Wastewater sludge - the challenges. What are the potentials of utilising the resources in sludge?

    Energy Technology Data Exchange (ETDEWEB)

    Kroiss, Helmut

    2003-07-01

    The actual best practice of urban water management has developed during the last 200 years and consists of: safe and reliable drinking water supply, sewerage to prevent hygienic problems and flooding in the settlements, mechanical -biological waste water treatment for receiving water protection. The hygienic and environmental goals of the urban water system have to be attained with a minimum of costs. Most of the drinking water supplied is used for the transport of pollution originating from human metabolism, washing and cleaning. Waste water contains all the substances which enter human metabolism as food, beverages, pharmaceuticals, a great variety of household chemicals and the substances discharged from trade and industry to the sewer system. Rain water is already contaminated by air pollution when it reaches the soil or other surfaces. Whatever material the rainwater gets into contact can be found in the waste water. As a consequence the composition of the waste water is a mirror of our civilisation and of human and urban metabolism. Waste water treatment results in two products which are closely related in their chemical composition: (1) treated waste water to be discharged to the receiving water, (2) wastewater sludge to be treated and disposed or (re)used without creating new (environmental) problems. All the compounds entering the waste water which are not completely degraded can be found in both products. The transfer coefficients between water and sludge differ widely and depend on physical and chemical equilibriums. The potentially hazardous compounds in the effluent and in the sludge belong to these compounds. Source control therefore is necessary for water protection and at the same time for low concentrations of potentially hazardous compounds in the sludge. It is also clear that improved biological treatment efficiency (longer sludge age) also results in lower loads of organic pollutants in the sludge, while physical-chemical treatment steps result

  2. Sludge accumulation and conversion to methane in a septic tank treating domestic wastewater or black water.

    Science.gov (United States)

    Elmitwalli, Tarek

    2013-01-01

    Although the septic tank is the most applied on-site system for wastewater pre-treatment, limited research has been performed to determine sludge accumulation and biogas production in the tank. Therefore a dynamic mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) was developed for anaerobic digestion of the accumulated sludge in a septic tank treating domestic wastewater or black water. The results showed that influent chemical oxygen demand (COD) concentration and hydraulic retention time (HRT) of the tank mainly control the filling time with sludge, while operational temperature governs characteristics of the accumulated sludge and conversion to methane. For obtaining stable sludge and high conversion, the tank needs to be operated for a period more than a year without sludge wasting. Maximum conversion to methane in the tank is about 50 and 60% for domestic wastewater and black water, respectively. The required period for sludge wasting depends on the influent COD concentration and the HRT, while characteristics of the wasted sludge are affected by operational temperature followed by the influent COD concentration and the HRT. Sludge production from the tank ranges between 0.19 to 0.22 and 0.13 to 0.15 L/(person.d), for the domestic wastewater and black water, respectively.

  3. Impact of high saline wastewaters on anaerobic granular sludge functionalities

    NARCIS (Netherlands)

    Jeison, D.A.; Rio, del A.; Lier, van J.B.

    2008-01-01

    Three UASB reactors were operated at different salinity levels in order to assess the effects on the granular sludge properties. High levels of activity inhibition were observed at sodium concentrations over 7 g Na+/L, which resulted in low applicable organic loading rates and VFA accumulation in

  4. IDENTIFICATION AND ECOPHYSIOLOGY OF ACTIVE DENITRIFIERS IN ACTIVATED SLUDGE

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Le-Quy, Vang; Nielsen, Kåre Lehmann

    reactor studies. To obtain better identification of active denitrifying communities in full-scale wastewater treatment plants (WWTPs) we applied DNA-SIP with 13C-labelled substrates, and RT-PCR of expressed denitrification genes (nirS, nirK and nosZ) upon various substrate-inductions. To come around...... were determined with quantitative FISH, while their active metabolic pathways were investigated directly in activated sludge with a tag-based metatranscriptomic approach under acetate-utilizing and denitrifying conditions. The different methods revealed a majority of denitrifiers in all WWTPs belonging...

  5. Dynamic modeling of sludge compaction and consolidation processes in wastewater secondary settling tanks

    NARCIS (Netherlands)

    Abusam, A.; Keesman, K.J.

    2009-01-01

    The double exponential settling model is the widely accepted model for wastewater secondary settling tanks. However, this model does not estimate accurately solids concentrations in the settler underflow stream, mainly because sludge compression and consolidation processes are not considered. In

  6. Briquette fuel production from wastewater sludge of beer industry and biodiesel production wastes

    Science.gov (United States)

    Nusong, P.; Puajindanetr, S.

    2018-04-01

    The production of industrial wastes is increasing each year. Current methods of waste disposal are severely impacting the environment. Utilization of industrial wastes as an alternative material for fuel is gaining interest due to its environmental friendliness. Thus, the objective of this research was to study the optimum condition for fuel briquettes produced from wastewater sludge of the beer industry and biodiesel production wastes. This research is divided into two parts. Part I will study the effects of carbonization of brewery wastewater sludge for high fixed carbon. Part II will study the ratio between brewery wastewater sludge and bleaching earth for its high heating value. The results show that the maximum fixed carbon of 10.01% by weight was obtained at a temperature of 350 °C for 30 minutes. The appropriate ratio of brewery wastewater sludge and bleaching earth by weight was 95:5. This condition provided the highest heating value of approximately 3548.10 kcal/kg.

  7. Global Perspectives on Activated Sludge Community Composition analyzed using 16S rRNA amplicon sequencing

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Saunders, Aaron Marc; Albertsen, Mads

    communities, and in this study activated sludge sampled from 32 Wastewater Treatment Plants (WWTPs) around the world was described and compared. The top abundant bacteria in the global activated sludge ecosystem were found and the core population shared by multiple samples was investigated. The results......Activated sludge is the most commonly applied bioprocess throughout the world for wastewater treatment. Microorganisms are key to the process, yet our knowledge of their identity and function is still limited. High-througput16S rRNA amplicon sequencing can reliably characterize microbial...

  8. Multiresistant Bacteria Isolated from Activated Sludge in Austria

    Directory of Open Access Journals (Sweden)

    Herbert Galler

    2018-03-01

    Full Text Available Wastewater contains different kinds of contaminants, including antibiotics and bacterial isolates with human-generated antibiotic resistances. In industrialized countries most of the wastewater is processed in wastewater treatment plants which do not only include commercial wastewater, but also wastewater from hospitals. Three multiresistant pathogens—extended spectrum β-lactamase (ESBL-harbouring Enterobacteriaceae (Gram negative bacilli, methicillin resistant Staphylococcus aureus (MRSA and vancomycin resistant Enterococci (VRE—were chosen for screening in a state of the art wastewater treatment plant in Austria. Over an investigation period of six months all three multiresistant pathogens could be isolated from activated sludge. ESBL was the most common resistance mechanism, which was found in different species of Enterobacteriaceae, and in one Aeromonas spp. Sequencing of ESBL genes revealed the dominance of genes encoding members of CTX-M β-lactamases family and a gene encoding for PER-1 ESBL was detected for the first time in Austria. MRSA and VRE could be isolated sporadically, including one EMRSA-15 isolate. Whereas ESBL is well documented as a surface water contaminant, reports of MRSA and VRE are rare. The results of this study show that these three multiresistant phenotypes were present in activated sludge, as well as species and genes which were not reported before in the region. The ESBL-harbouring Gram negative bacilli were most common.

  9. Multiresistant Bacteria Isolated from Activated Sludge in Austria

    Science.gov (United States)

    Feierl, Gebhard; Petternel, Christian; Reinthaler, Franz F.; Haas, Doris; Habib, Juliana; Kittinger, Clemens; Luxner, Josefa

    2018-01-01

    Wastewater contains different kinds of contaminants, including antibiotics and bacterial isolates with human-generated antibiotic resistances. In industrialized countries most of the wastewater is processed in wastewater treatment plants which do not only include commercial wastewater, but also wastewater from hospitals. Three multiresistant pathogens—extended spectrum β-lactamase (ESBL)-harbouring Enterobacteriaceae (Gram negative bacilli), methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococci (VRE)—were chosen for screening in a state of the art wastewater treatment plant in Austria. Over an investigation period of six months all three multiresistant pathogens could be isolated from activated sludge. ESBL was the most common resistance mechanism, which was found in different species of Enterobacteriaceae, and in one Aeromonas spp. Sequencing of ESBL genes revealed the dominance of genes encoding members of CTX-M β-lactamases family and a gene encoding for PER-1 ESBL was detected for the first time in Austria. MRSA and VRE could be isolated sporadically, including one EMRSA-15 isolate. Whereas ESBL is well documented as a surface water contaminant, reports of MRSA and VRE are rare. The results of this study show that these three multiresistant phenotypes were present in activated sludge, as well as species and genes which were not reported before in the region. The ESBL-harbouring Gram negative bacilli were most common. PMID:29522474

  10. Health risk assessment along the wastewater and faecal sludge management and reuse chain of Kampala, Uganda: a visualization

    Directory of Open Access Journals (Sweden)

    Samuel Fuhrimann

    2014-11-01

    Full Text Available Reuse of wastewater in agriculture is a common feature in the developing world. While this strategy might con- tribute to the livelihood of farming communities, there are health risks associated with the management and reuse of wastewater and faecal sludge. We visualise here an assessment of health risks along the major wastewater channel in Kampala, Uganda. The visualization brings to bear the context of wastewater reuse activities in the Nakivubo wetlands and emphasises interconnections to disease transmission pathways. The contextual features are complemented with findings from environmental sampling and a cross-sectional epidemiological survey in selected exposure groups. Our documentation can serve as a case study for a step-by-step implementation of risk assessment and management as described in the World Health Organization’s 2006 guidelines for the safe use of wastewater, greywater and excreta in light of the forthcoming san- itation safety planning approach.

  11. Health risk assessment along the wastewater and faecal sludge management and reuse chain of Kampala, Uganda: a visualization.

    Science.gov (United States)

    Fuhrimann, Samuel; Winkler, Mirko S; Schneeberger, Pierre H H; Niwagaba, Charles B; Buwule, Joseph; Babu, Mohammed; Medlicott, Kate; Utzinger, Jürg; Cissé, Guéladio

    2014-11-01

    Reuse of wastewater in agriculture is a common feature in the developing world. While this strategy might contribute to the livelihood of farming communities, there are health risks associated with the management and reuse of wastewater and faecal sludge. We visualise here an assessment of health risks along the major wastewater channel in Kampala, Uganda. The visualization brings to bear the context of wastewater reuse activities in the Nakivubo wetlands and emphasises interconnections to disease transmission pathways. The contextual features are complemented with findings from environmental sampling and a cross-sectional epidemiological survey in selected exposure groups. Our documentation can serve as a case study for a step-by-step implementation of risk assessment and management as described in the World Health Organization's 2006 guidelines for the safe use of wastewater, greywater and excreta in light of the forthcoming sanitation safety planning approach.

  12. Application of dielectric constant measurement in microwave sludge disintegration and wastewater purification processes.

    Science.gov (United States)

    Kovács, Petra Veszelovszki; Lemmer, Balázs; Keszthelyi-Szabó, Gábor; Hodúr, Cecilia; Beszédes, Sándor

    2018-05-01

    It has been numerously verified that microwave radiation could be advantageous as a pre-treatment for enhanced disintegration of sludge. Very few data related to the dielectric parameters of wastewater of different origins are available; therefore, the objective of our work was to measure the dielectric constant of municipal and meat industrial wastewater during a continuous flow operating microwave process. Determination of the dielectric constant and its change during wastewater and sludge processing make it possible to decide on the applicability of dielectric measurements for detecting the organic matter removal efficiency of wastewater purification process or disintegration degree of sludge. With the measurement of dielectric constant as a function of temperature, total solids (TS) content and microwave specific process parameters regression models were developed. Our results verified that in the case of municipal wastewater sludge, the TS content has a significant effect on the dielectric constant and disintegration degree (DD), as does the temperature. The dielectric constant has a decreasing tendency with increasing temperature for wastewater sludge of low TS content, but an adverse effect was found for samples with high TS and organic matter contents. DD of meat processing wastewater sludge was influenced significantly by the volumetric flow rate and power level, as process parameters of continuously flow microwave pre-treatments. It can be concluded that the disintegration process of food industry sludge can be detected by dielectric constant measurements. From technical purposes the applicability of dielectric measurements was tested in the purification process of municipal wastewater, as well. Determination of dielectric behaviour was a sensitive method to detect the purification degree of municipal wastewater.

  13. Removal of phosphorus from wastewater using ferroxysorb sorption media produced from amd sludge

    Science.gov (United States)

    Sibrell, P.L.; Tucker, T.W.; Kehler, T.; Fletcher, J.W.

    2008-01-01

    Treatment of acid mine drainage (AMD), whether with lime, limestone, caustic or simple aeration, nearly always results in generation of a metal hydroxide sludge. Disposal of the sludge often constitutes a significant fraction of the operating cost for the AMD treatment plant. Research at the USGS - Leetown Science Center has shown that AMD sludge, with its high content of aluminum and iron oxides, has a high affinity of phosphorus (P). Anthropogenic sources of P are associated with eutrophication and degradation of aquatic environments, resulting in anoxic dead zones in certain sensitive waterways. In this paper, we describe a method of converting the AMD sludge from a liability into an asset - Ferroxysorb P removal media - which can be used to remove excess P from wastewater. Three different Ferroxysorb media samples were produced from differing AMD sources and tested for P removal. Adsorption isotherms confirmed that the media had a high sorption capacity for P, as high as 19,000 mg/kg. The technology was demonstrated at an active fish hatchery, where the media remained in service for over three months without stripping or regeneration. Over that period of time, the calculated P removal was 50%, even at a very low influent P concentration of 60 parts per billion. In summary, use of the AMD-derived Ferroxysorb sorption media will reduce AMD treatment costs while at the same time helping to resolve the pressing environmental issue of eutrophication and degradation of sensitive waterways.

  14. 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))

    2007-09-15

    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)

  15. Vitrification Studies with DOE Low-Level Mixed Waste Wastewater Treatment Sludges

    International Nuclear Information System (INIS)

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

    1995-01-01

    Vitrification studies with simulated Low Level Mixed Waste (LLMW) sludges were performed at the Savannah River Technology Center (SRTC). These studies focused on finding the optimum glass compositions for four simulated LLMW wastewater treatment sludges and were based on both crucible-scale and pilot-scale studies. Optimum compositions were determined based on the maximum waste loading achievable without sacrificing glass integrity

  16. Influence of temperature on hydrogen production from bread mill wastewater by sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Tang, G.L.; Huang, J.; Li, Y.Y.; Sun, Z.J. [China Agricultural Univ., Beijing (China). College of Resources and Environmental Sciences; Tang, Q.Q. [Nanjing Univ., Nanjing (China). Medical School

    2008-07-01

    Hydrogen (H{sub 2}) energy has been touted as a sustainable and clean energy source that can solve environmental problems such as acid rain, greenhouse gases and transboundary pollution. While most hydrogen is currently produced from nonrenewable sources such as oil, natural gas, and coal, these processes are energy-intensive and costly. The biological production of hydrogen using fermentative bacteria is an environmentally friendly and energy-saving process which has recently attracted much attention as an effective way of converting biomass into H{sub 2}. Waste-based H{sub 2} production processes mainly include wastewater from paper mills, municipal solid waste, rice winery wastewater, and food wastewater from cafeterias. This study investigated the use of bread mill wastewater for biological production of hydrogen due to its high production potential. Annual bread production in China is estimated to be over 1.5 million tons, producing 10 m{sup 3} of wastewater per ton of bread. The wastewater has high chemical oxygen demand and carbohydrate concentrations and is therefore suitable for anaerobic treatment processes. This study evaluated the effect of temperature on H{sub 2} production from bread mill wastewater by sewage sludge in lab-scale experiments. H{sub 2} production, the distribution of volatile fatty acids and the lag-phase time were influenced by temperature. H{sub 2} production and H{sub 2} yield increased with increasing temperature. The optimal temperature for H{sub 2} production was 50 degrees C. Butyrate, acetate and alcohol were the main by-products of H{sub 2} fermentation. According to 16S rDNA analysis, the dominant microflora was Clostridium, but the microbial species varied with temperature. The activation energy for H{sub 2} production was estimated to be 92 kJ per mol for bread mill wastewater. It was concluded that bread mill wastewater could potentially serve as a substrate for H{sub 2} production. This research provides a means of

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

    Science.gov (United States)

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

    2012-01-01

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

  18. Toxicities of triclosan, phenol, and copper sulfate in activated sludge.

    Science.gov (United States)

    Neumegen, Rosalind A; Fernández-Alba, Amadeo R; Chisti, Yusuf

    2005-04-01

    The effect of toxicants on the BOD degradation rate constant was used to quantitatively establish the toxicity of triclosan, phenol, and copper (II) against activated sludge microorganisms. Toxicities were tested over the following ranges of concentrations: 0-450 mg/L for phenol, 0-2 mg/L for triclosan, and 0-35 mg/L for copper sulfate (pentahydrate). According to the EC(50) values, triclosan was the most toxic compound tested (EC(50) = 1.82 +/- 0.1 mg/L), copper (II) had intermediate toxicity (EC(50) = 18.3 +/- 0.37 mg/L), and phenol was the least toxic (EC(50) = 270 +/- 0.26 mg/L). The presence of 0.2% DMSO had no toxic effect on the activated sludge. The toxicity evaluation method used was simple, reproducible, and directly relevant to activated sludge wastewater treatment processes.

  19. Low intensity surplus activated sludge pretreatment before anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2017-12-01

    Full Text Available Sewage sludge (municipal, or industrial treatment is still a problem in so far that it is not satisfactorily resolved in terms of cost and final disposal. Two common forms of sludge disposal are possible; the first being direct disposal on land (including agriculture and the second being incineration (ash production, although neither of these methods are universally applied. Simplifying the issue, direct sludge disposal on land is seldom applied for sanitary and environmental reasons, while incineration is not popular for financial (high costs reasons. Very often medium and large wastewater treatment plants apply anaerobic digestion for sludge hygiene principles, reducing the amount to be disposed and for biogas (energy production. With the progress in sewage biological treatment aiming at nutrient removal, primary sludge has been omitted in the working processes and only surplus activated sludge requires handling. Anaerobic digestion of waste activated sludge (WAS is more difficult due to the presence of microorganisms, the decomposition of which requires a relatively long time for hydrolysis. In order to upgrade the hydrolysis effects, several different pre-treatment processes have already been developed and introduced. The additional pre-treatment processes applied are aimed at residual sludge bulk mass minimization, shortening of the anaerobic digestion process or higher biogas production, and therefore require additional energy. The water-energy-waste Nexus (treads of of the benefits and operational difficulties, including energy costs are discussed in this paper. The intensity of pre-treatment processes to upgrade the microorganism’s hydrolysis has crucial implications. Here a low intensity pre-treatment process, alkalisation and hydrodynamic disintegration - hybrid process - were presented in order to achieve sufficient effects of WAS anaerobic digestion. A sludge digestion efficiency increase expressed as 45% biogas additional

  20. Physico-chemical pre-treatment and biotransformation of wastewater and wastewater sludge--fate of bisphenol A.

    Science.gov (United States)

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

    2010-02-01

    Bisphenol A (BPA), an endocrine disrupting compound largely used in plastic and paper industry, ends up in aquatic systems via wastewater treatment plants (WWTPs) among other sources. The identification and quantification of BPA in wastewater (WW) and wastewater sludge (WWS) is of major interest to assess the endocrine activity of treated effluent discharged into the environment. Many treatment technologies, including various pre-treatment methods, such as hydrolysis, Fenton oxidation, peroxidation, ultrasonication and ozonation have been developed in order to degrade BPA in WW and WWS and for the production of WWS based value-added products (VAPs). WWS based VAPs, such as biopesticides, bioherbicides, biofertilizers, bioplastics and enzymes are low cost biological alternatives that can compete with chemicals or other cost intensive biological products in the current markets. However, this field application is disputable due to the presence of these organic compounds which has been discussed with a perspective of simultaneous degradation. The pre-treatment produces an impact on rheology as well as value-addition which has been reviewed in this paper. Various analytical techniques available for the detection of BPA in WW and WWS are also discussed. Presence of heavy metals and possible thermodynamical behavior of the compound in WW and WWS can have major impact on BPA removal, which is also included in the review.

  1. Nutrient content in maize fertilized with tannery sludge vermicompost and irrigated with domestic wastewater

    Directory of Open Access Journals (Sweden)

    Guilherme Malafaia

    2016-11-01

    Full Text Available This study analyzed the macro and micronutrient content of maize leaves (Zea mays L. grown in soil containing tannery sludge vermicomposting and irrigated with wastewater. The arrangement of the treatments consisted of a factorial 2x6 (two types of irrigation and six kinds of fertilizer in a completely randomized design, with five repetitions, totaling sixty experimental units. The following experimental units, irrigated with supply water (A and household wastewater (R, were established: (T1 Control Soil, with no chemical fertilization and no vermicomposting; (T2 Soil + NPK; (T3 Soil + primary sludge vermicompost; (T4 Soil + P + primary sludge vermicompost; (T5 Soil + P + liming sludge vermicompost; and (T6 Soil + liming sludge vermicompost. For the leaf-tissue analysis, the opposite whole leaf below the first (upper ear was collected from each plant, excluding the midrib at the onset of the female inflorescence. The results showed that both wastewater and the tannery sludge vermicomposts can be a good source of nutrients for maize plants, since the macro and micronutrients in the leaves of plants were satisfactory and no signs or symptoms of toxicity were observed. While leaf analysis alone is insufficient to assess the nutritional status of plants, this study innovatively suggests the potential beneficial use of a combination of wastewater and tannery sludge vermicompost in the cultivation of corn, motivating new research.

  2. Cost minimization in a full-scale conventional wastewater treatment plant: associated costs of biological energy consumption versus sludge production.

    Science.gov (United States)

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

    2017-11-01

    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.

  3. RESPIROMETRIC ACTIVITY OF ACTIVATED SLUDGE AND BIOFILM IN IFAS-MBBR SYSTEM

    Directory of Open Access Journals (Sweden)

    Paula Piechna

    2017-07-01

    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.

  4. [From waste to treasure: turning activated sludge into bioplastic poly-3-hydroxybutyrate].

    Science.gov (United States)

    Chen, Jia'ni

    2017-12-25

    Large quantity of activated sludge is generated from wastewater treatment but without yet an appropriate deposition. High temperature can lyse the activate sludge so that nitrogen and phosphorus containing nutrients are released. Halomonas CJN was found to grow on the heat lysed activated sludge and glucose for production of bioplastic poly-3-hydroxybutyrate (PHB) in the absence of yeast extract, nitrogen and phosphorus sources as well as trace elements. This reduces the PHB production cost significantly. Furthermore, acetic acid formed from anaerobic fermentation of heat lysed activated sludge can be used to replace glucose for cell growth but not much for PHB production. After construction of an additional PHB synthesis pathway in Halomonas CJN, we can produce PHB entirely from heat lysed activated sludge, reducing production cost of PHB roughly from ¥ 30 000 Yuan/ton to ¥ 20 000 Yuan/ton, thus turning waste activated sludge to valuable raw material resource.

  5. Investigating the inhibitory effect of cyanide, phenol and 4-nitrophenol on the activated sludge process employed for the treatment of petroleum wastewater.

    Science.gov (United States)

    Inglezakis, V J; Malamis, S; Omirkhan, A; Nauruzbayeva, J; Makhtayeva, Z; Seidakhmetov, T; Kudarova, A

    2017-12-01

    In this work, the inhibitory effect of cyanide, phenol and 4-nitrophenol on the activated sludge process was investigated. The inhibition of the aerobic oxidation of organic matter, nitrification and denitrification were examined in batch reactors by measuring the specific oxygen uptake rate (sOUR), the specific ammonium uptake rate (sAUR) and the specific nitrogen uptake rate (sNUR) respectively. The tested cyanide, phenol and 4-nitrophenol concentrations were 0.2-1.7 mg/L, 4.8-73.1 mg/L and 8.2-73.0 mg/L respectively. Cyanide was highly toxic as it significantly (>50%) inhibited the activity of autotrophic biomass, heterotrophic biomass under aerobic conditions and denitrifiers even at relatively low concentrations (1.0-1.7 mgCN - /L). The determination of the half maximum inhibitory concentration (IC 50 ) confirmed this, since for cyanide IC 50 values were very low for the examined bioprocesses (25 mg/L) for the tested bioprocesses since appreciable concentrations were required to accomplish significant inhibition. The autotrophic bacteria were more sensitive to phenol than the aerobic heterotrophs. The denitrifiers were found to be very resistant to phenol. Copyright © 2016. Published by Elsevier Ltd.

  6. Efficiency of Worm Reactors in Reducing Sludge Volume in Activated Sludge Systems

    Directory of Open Access Journals (Sweden)

    Azam Naderi

    2017-01-01

    Full Text Available The activated sludge process is the most widely used on a global scale for the biological treatment of both domestic and industrial effluents. One problem associated with the process, however, is the high volume of sludge produced. Excess sludge treatment and disposal account for up to 60% of the total operating costs of urban wastewater treatment plants due to the stringent environmental regulations on excess sludge disposal. These strict requirements have encouraged a growing interest over the last few years in reducing sludge volumes produced at biological treatment plants and a number of physical, chemical, and mechanical methods have been accordingly developed for this purpose. The proposed methods are disadvantaged due to their rather high investment and operation costs. An alternative technology that avoids many of these limitations is the worm reactor. In this study, the characteristics of this technology are investigated while the related literature is reviewed to derive the optimal conditions for the operation of this process in different situations.

  7. 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

    2013-07-01

    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

  8. Hexavalent chromium removal using aerobic activated sludge batch ...

    African Journals Online (AJOL)

    The following Cr(VI) removal systems were tested: activated sludge alone; activated sludge with an external electron donor (5 g/. of lactose); activated sludge with PAC addition (4 g/.); activated sludge with both PAC and lactose; and PAC alone. The results reported here showed that activated sludges are capable of ...

  9. 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.

    2017-06-01

    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.

  10. Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO2/sewage sludge-based activated carbon nanocomposites

    Science.gov (United States)

    Rashed, M. Nageeb; Eltaher, M. A.; Abdou, A. N. A.

    2017-12-01

    Nanocomposite TiO2/ASS (TiO2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO2/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO2/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO2 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd2+ from bi-pollutant solution was achieved with TiO2/ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO2/ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO2/ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO2/ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd2+ it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.

  11. Combination of alkaline and microwave pretreatment for disintegration of meat processing wastewater sludge.

    Science.gov (United States)

    Erden, G

    2013-01-01

    Meat processing wastewater sludge has high organic content but it is very slow to degrade in biological processes. Anaerobic digestion may be a good alternative for this type of sludge when the hydrolysis, known to be the rate-limiting step of biological sludge anaerobic degradation, could be eliminated by disintegration. This investigation deals with disintegration of meat processing wastewater sludge. Microwave (MW) irradiation and combined alkaline pretreatment and MW irradiation were applied to sludge for disintegration purposes. Disintegration performance of the methods was evaluated with disintegration degree based on total and dissolved organic carbon calculations (DD(TOC)), and the solubilization of volatile solids (S(VS)) in the pretreated sludge. Optimum conditions were found to be 140 degrees C and 30 min for MW irradiation using response surface methodology (RSM) and pH = 13 for combined pretreatment. While DD(TOC) was observed as 24.6% and 54.9, S(VS) was determined as 8.54% and 42.5% for MW pretreated and combined pretreated sludge, respectively. The results clearly show that pre-conditioning of sludge with alkaline pretreatment played an important role in enhancing the disintegration efficiency of subsequent MW irradiation. Disintegration methods also affected the anaerobic biodegradability and dewaterability of sludge. An increase of 23.6% in biogas production in MW irradiated sludge was obtained, comparing to the raw sludge at the end of the 35 days of incubation. This increase was observed as 44.5% combined pretreatment application. While MW pretreatment led to a little improvement of the dewatering performance of sludge, in combined pretreatment NaOH deteriorates the sludge dewaterability.

  12. Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

    Science.gov (United States)

    Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

    2002-10-01

    Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

  13. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

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

    Directory of Open Access Journals (Sweden)

    Zubayeda Zahan

    2016-01-01

    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.

  15. Preliminary studies on the use of irradiation for decontaminating water and sludge in wastewater treatment plants in Chile

    International Nuclear Information System (INIS)

    Villanueva, Loreto; Schrader, Rosemarie

    1999-01-01

    This work describes the activities carried out to date by the Chilean Nuclear Energy Commission, CCHEN, in prospecting the application of gamma and electron beam irradiation to the decontamination of sewage water and sludge in the country. Sludge, in particular, will become a relevant environmental problem in the coming years, because of the large amounts that will be generated, due to the construction of many wastewater treatment plants in the country. The main study consisted of experimental gamma irradiation tests on representative samples of digested sludge from two pilot wastewater treatment plants operating in Santiago. This study showed the technical feasibility of using low irradiation doses, of around 2-3 kGy to significantly reduce the pathogen content in this sludge. Preliminary tests were also carried out to determine that the disinfected sludge was fit for agricultural use due to its nutrient content. A preliminary technical and economic evaluation is being prepared on the use of gamma irradiation for sludge disinfection, as a complement to the experimental studies. With this evaluation a feasible process has been outlined for using gamma irradiation in conjunction with conventional processes for the sludge disinfection or hygienization in domestic wastewater treatment plants, in order to produce a useful material for agricultural use that meets the demanding EPA standards when classified as class A sludge, which permits agricultural use without sanitary restrictions. Several evaluations have been made to determine the potential use of irradiation for water and industrial wastewater effluents decontamination, considering normative standards as well as technical and economic aspects. One of these has been the preliminary evaluation of using electron beam irradiation for disinfecting drinking water, which has the technical advantage of preventing the formation of trihalomethanes, that occur in water chlorination due to the presence of natural humic

  16. DISCUSSION ON LEGAL AND PRACTICAL JUSTIFICATION OF USING WASTEWATER SEWAGE SLUDGE

    Directory of Open Access Journals (Sweden)

    Jan Siuta

    2015-11-01

    Full Text Available Unjustifiable introduction to the soil of sewage sludge from a Białystok wastewater treatment facility was subject to an investigation conducted by the District Public Prosecutor in Białystok, who charged the Institute of Environmental Protection – National Research Institute (IEP-NRI with the task to produce (based on the investigation acts an expert opinion “on unlicensed disposal of municipal wastewater sludge under conditions which can threaten human life or health or significantly depress the quality of land surface or cause large scale damage to the environment, i.e. the deed provided for under Article 183 §1 of the Penal Code as well as other deeds”. The opinion was elaborated by Professor Jan Siuta, a head of the Land Protection Department at the IEP-NRI. The outline of his opinion was sent to the Minister of the Environment together with guidelines for necessary activities to be taken following the provisions of Article 96 §1 of the Waste Law of December 14, 2012 (Official Journal of 8 January 2013, item 21. The opinion notwithstanding, the Minister of the Environment was sent a critical commentary on the Appendix 1 to the order of the Minister of the Environment as of March 21, 2006 (Official Journal No 49, item 356 on waste types and conditions for their recycling in the R14 process. The commentary focused on the application of “furnace waste from carbon fired power plants to produce the so-called reclamation coating; the waste needs to be mixed 1 : 1 with dehydrated sludge and applied as maximally 1 m thick layer in the case of shrub planting and 2 m thick layer in the case of tree planting”. It should be added that in the latter case it is admitted to use as much as up to 10 000 tonnes of wastewater sludge per one ha. The Department of Waste Management replied in writing to both notes directed to Ministry of the Environment; voicing the statement that the enforced regulations do not need to be amended since they remain

  17. Anaerobic bioleaching of metals from waste activated sludge

    International Nuclear Information System (INIS)

    Meulepas, Roel J.W.; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E.; Lens, Piet N.L.

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g −1 of copper, 487 μg g −1 of lead, 793 μg g −1 of zinc, 27 μg g −1 of nickel and 2.3 μg g −1 of cadmium. During the anaerobic acidification of 3 g dry weight L −1 waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner

  18. Anaerobic bioleaching of metals from waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Meulepas, Roel J.W., E-mail: roel.meulepas@wetsus.nl [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  19. Co-conditioning and dewatering of chemical sludge and waste activated sludge.

    Science.gov (United States)

    Chang, G R; Liu, J C; Lee, D J

    2001-03-01

    The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed.

  20. Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO2/sewage sludge-based activated carbon nanocomposites.

    Science.gov (United States)

    Rashed, M Nageeb; Eltaher, M A; Abdou, A N A

    2017-12-01

    Nanocomposite TiO 2 /ASS (TiO 2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO 2 /ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO 2 /ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd 2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO 2  : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd 2+ from bi-pollutant solution was achieved with TiO 2 /ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO 2 /ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO 2 /ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO 2 /ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd 2+ it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.

  1. MiDAS Field Guide – a Comprehensive Online Source of Information About the Microbes of Activated Sludge

    DEFF Research Database (Denmark)

    Nierychlo, Marta; McIlroy, Simon Jon; Saunders, Aaron Marc

    this information in MiDAS field guide (www.midasfieldguide.org). MiDAS taxonomy gives a solid foundation for the study of microbial ecology of the wastewater treatment processes. The online MiDAS field guide links the identity of genera that are important for the wastewater treatment process to details about...... guide to the microbes of activated sludge by comparing microbial community composition in 32 WWTPs located worldwide. This will facilitate a better understanding of the ecology of the ecosystem of activated sludge. Reference: McIlroy et al. MiDAS: the field guide to the microbes of activated sludge...... on a survey of 25 full-scale Danish wastewater treatment plants over 6 years and using MiDAS taxonomy, we have collected more than 150 key organisms in activated sludge wastewater treatment systems, linked their identity with available information on their function and distribution and included...

  2. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D`Avila, J.S.; Nascimento, R.R. [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1993-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  3. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D` Avila, J S; Nascimento, R R [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1994-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  4. Chlorella vulgaris cultivation in sludge extracts from 2,4,6-TCP wastewater treatment for toxicity removal and utilization.

    Science.gov (United States)

    Wang, Lu; Chen, Xiurong; Wang, Hualin; Zhang, Yuying; Tang, Qingjie; Li, Jiahui

    2017-02-01

    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.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

    Elissen, H.J.H.

    2007-01-01

    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

  7. Mechanism, kinetics and application studies on enhanced activated sludge by interior microelectrolysis.

    Science.gov (United States)

    Yang, Xiaoyi; Xue, Yu; Wang, Wenna

    2009-01-01

    Enhanced activated sludge by interior microelectrolysis (EAIM) was studied to treat textile wastewater, kinetics, mechanism and application of which were also discussed in comparison with traditional activated sludge and interior microelectrolysis, respectively. The results of kinetics study indicated three different processes all followed first-order kinetics well. In EAIM, three impact factors take effects on COD removal, which are flocculation, activated sludge and electrophoresis and redox. In terms of assumption of no interaction among three COD removal mechanisms, 49.6% of the total COD removal is ascribed to flocculation, 30.1% to activated sludge and 20.3% to electrophoresis and redox. EAIM showed its advantages in COD removal efficiency, extensive adaptability to complex composition and wide range of pH. EAIM-aerobic process provided an efficient and economic performance for dealing with textile wastewater.

  8. Self-heating of dried industrial wastewater sludge: lab-scale investigation of supporting conditions.

    Science.gov (United States)

    Della Zassa, M; Biasin, A; Zerlottin, M; Refosco, D; Canu, P

    2013-06-01

    We studied the reactivity of dried sludge produced by treatment of wastewater, mainly from tanneries. The solids transformations have been first characterized with thermal analysis (TGA and DSC) proving that exothermic transformation takes place at fairly low temperature, before the total organic combustion that occurs in air above 400°C. The onset of low temperature reactions depends on the heating rate and it can be below 100°C at very small heating rate. Then, we reproducibly determined the conditions to trigger dried sludge self-heating at the laboratory scale, on samples in the 0.2-0.3 kg size. Thermal insulation, some aeration and addition of water are key factors. Mastering the self-heating at this scale allows more detailed investigations as well as manipulation of conditions, to understand its nature, course and remediation. Here we report proves and discussions on the role of air, water, particle size, porosity and biological activity, as well as proving that also dried sludge from similar sources lead to self-heating. Tests demonstrate that air and water are simultaneously required for significant self-heating to occur. They act in diverging directions, both triggering the onset of the reactions and damping the temperature rise, by supporting heat loss. The higher the O2 concentration, the higher the solids heating rate. More added water prolongs the exothermic phase. Further additions of water can reactivate the material. Water emphasizes the exothermic processes, but it is not sufficient to start it in an air-free atmosphere. The initial solid moisture concentration (between 8% and 15%) affects the onset of self-heating as intuitive. The sludge particles size strongly determines the strength and extent of the heat release, indicating that surface reactions are taking place. In pelletized particles, limitations to water and air permeability mitigates the reaction course. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Ge, Huoqing; Batstone, Damien; Keller, Jurg

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2016-01-01

    Conclusion: Application of slaughterhouse wastewater as feed wastewater demonstrated that the slaughterhouse wastewater to be more effective in promoting the formation of anaerobic granules and granule size in UASB reactor.

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

    Science.gov (United States)

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

    2009-01-01

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

  12. Rapid adaptation of activated sludge bacteria into a glycogen accumulating biofilm enabling anaerobic BOD uptake.

    Science.gov (United States)

    Hossain, Md Iqbal; Paparini, Andrea; Cord-Ruwisch, Ralf

    2017-03-01

    Glycogen accumulating organisms (GAO) are known to allow anaerobic uptake of biological oxygen demand (BOD) in activated sludge wastewater treatment systems. In this study, we report a rapid transition of suspended activated sludge biomass to a GAO dominated biofilm by selective enrichment using sequences of anaerobic loading followed by aerobic exposure of the biofilm to air. The study showed that within eight weeks, a fully operational, GAO dominated biofilm had developed, enabling complete anaerobic BOD uptake at a rate of 256mg/L/h. The oxygen uptake by the biofilm directly from the atmosphere had been calculated to provide significant energy savings. This study suggests that wastewater treatment plant operators can convert activated sludge systems readily into a "passive aeration" biofilm that avoids costly oxygen transfer to bulk wastewater solution. The described energy efficient BOD removal system provides an opportunity to be coupled with novel nitrogen removal processes such as anammox. Copyright © 2016. Published by Elsevier Ltd.

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Toxicity of carbon nanotubes to the activated sludge process

    International Nuclear Information System (INIS)

    Luongo, Lauren A.; Zhang Xiaoqi

    2010-01-01

    The discharge of carbon nanotubes (CNTs) from industrial waste or disposal of such materials from commercial and/or domestic use will inevitably occur with increasing production and enter into wastewater treatment facilities with unknown consequences. Therefore, a better knowledge of the toxicity of CNTs to biological processes in wastewater treatment will be critical. This study examined the toxicity of multi-walled carbon nanotubes (MWCNTs) on the microbial communities in activated sludge. A comparative study using the activated sludge respiration inhibition test was performed on both unsheared mixed liquor and sheared mixed liquor to demonstrate the potential toxicity posed by MWCNTs and to illustrate the extent of extracellular polymeric substances (EPS) in protecting the microorganisms from the toxicity of CNTs. Respiration inhibition was observed for both unsheared and sheared mixed liquor when MWCNTs were present, however, greater respiration inhibition was observed for the sheared mixed liquor. The toxicity observed by the respiration inhibition test was determined to be dose-dependent; the highest concentration of MWCNTs exhibited the highest respiration inhibition. Scanning Electron Microscopy (SEM) images demonstrated direct physical contact between MWCNTs and activated sludge flocs.

  15. From municipal/industrial wastewater sludge and FOG to fertilizer: A proposal for economic sustainable sludge management.

    Science.gov (United States)

    Bratina, Božidar; Šorgo, Andrej; Kramberger, Janez; Ajdnik, Urban; Zemljič, Lidija Fras; Ekart, Janez; Šafarič, Riko

    2016-12-01

    After a ban on the depositing of untreated sludge in landfills, the sludge from municipal and industrial water-treatment plants can be regarded as a problem. Waste products of the water treatment process can be a problem or an opportunity - a source for obtaining raw materials. In the European Union, raw sludge and fats, oil and grease (FOG) from municipal and industrial wastewater treatment plants (WWTP) cannot be deposited in any natural or controlled environment. For this reason, it must be processed (stabilized, dried) to be used later as a fertilizer, building material, or alternative fuel source suitable for co-incineration in high temperature furnaces (power plants or concrete plants). The processes of drying sludge, where heat and electricity are used, are energy consuming and economically unattractive. Beside energy efficiency, the main problem of sludge drying is in its variability of quality as a raw material. In addition to this, sludge can be contaminated by a number of organic and inorganic pollutants and organisms. Due to the presence or absence of pollutants, different end products can be economically interesting. For example, if the dried sludge contains coliform bacteria, viruses, helminths eggs or smaller quantities of heavy metals, it cannot be used as a fertilizer but can still be used as a fuel. The objectives of the current article is to present a batch-processing pilot device of sludge or digestate that allows the following: (1) low pressure and low temperature energy effective drying of from 10 to 40% remaining water content, (2) disinfection of pathogen (micro)organisms, (3) heavy metal reduction, (4) production of products of predetermined quality (e.g. containing different quantities of water; it can be used as a fertilizer, or if the percentage of water in the dry sludge is decreased to 10%, then the dried sludge can be used as a fuel with a calorific value similar to coal). An important feature is also the utilization of low

  16. Activated sludge process simulator ASP-Sim, Part-1: Bod and ...

    African Journals Online (AJOL)

    The most commonly used biological treatment of municipal and industrial wastewater is the Activated Sludge Process. The design of activated process is usually done manually; this is ... is a useful tool for predicting the effect of temperature on design and operation of completely mixed activated plant design and operation.

  17. Full-scale effects of addition of sludge from water treatment stations into processes of sewage treatment by conventional activated sludge.

    Science.gov (United States)

    Luiz, Marguti André; Sidney Seckler, Ferreira Filho; Passos, Piveli Roque

    2018-06-01

    An emerging practice for water treatment plant (WTP) sludge is its disposal in wastewater treatment plants (WWTP), an alternative that does not require the installation of sludge treatment facilities in the WTP. This practice can cause both positive and negative impacts in the WWTP processes since the WTP sludge does not have the same characteristics as domestic wastewater. This issue gives plenty of information in laboratory and pilot scales, but lacks data from full-scale studies. The main purpose of this paper is to study the impact of disposing sludge from the Rio Grande conventional WTP into the ABC WWTP, an activated sludge process facility. Both plants are located in São Paulo, Brazil, and are full-scale facilities. The WTP volumetric flow rate (4.5 m³/s) is almost three times that of WWTP (1.6 m³/s). The data used in this study came from monitoring the processes at both plants. The WWTP liquid phase treatment analysis included the variables BOD, COD, TSS, VSS, ammonia, total nitrogen, phosphorus and iron, measured at the inlet, primary effluent, mixed liquor, and effluent. For the WWTP solids treatment, the parameters tested were total and volatile solids. The performance of the WWTP process was analyzed with and without sludge addition: 'without sludge' in years 2005 and 2006 and 'with sludge' from January 2007 to March 2008. During the second period, the WTP sludge addition increased the WWTP removal efficiencies for solids (93%-96%), organic matter (92%-94% for BOD) and phosphorus (52%-88%), when compared to the period 'without sludge'. These improvements can be explained by higher feed concentrations combined to same or lower effluent concentrations in the 'with sludge' period. No critical negative impacts occurred in the sludge treatment facilities, since the treatment units absorbed the extra solids load from the WTP sludge. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Sequencing Batch Reactor and Bacterial Community in Aerobic Granular Sludge for Wastewater Treatment of Noodle-Manufacturing Sector

    Directory of Open Access Journals (Sweden)

    Tang Thi Chinh

    2018-03-01

    Full Text Available The sequencing batch reactor (SBR has been increasingly applied in the control of high organic wastewater. In this study, SBR with aerobic granular sludge was used for wastewater treatment in a noodle-manufacturing village in Vietnam. The results showed that after two months of operation, the chemical oxygen demand, total nitrogen and total phosphorous removal efficiency of aerobic granular SBR reached 92%, 83% and 75%, respectively. Bacterial diversity and bacterial community in wastewater treatment were examined using Illumina Miseq sequencing to amplify the V3-V4 regions of the 16S rRNA gene. A high diversity of bacteria was observed in the activated sludge, with more than 400 bacterial genera and 700 species. The predominant genus was Lactococcus (21.35% mainly containing Lactococcus chungangensis species. Predicted functional analysis showed a high representation of genes involved in membrane transport (12.217%, amino acid metabolism (10.067%, and carbohydrate metabolism (9.597%. Genes responsible for starch and sucrose metabolism accounted for 0.57% of the total reads and the composition of starch hydrolytic enzymes including α-amylase, starch phosphorylase, glucoamylase, pullulanase, α-galactosidase, β-galactosidase, α-glucosidase, β-glucosidase, and 1,4-α-glucan branching enzyme. The presence of these enzymes in the SBR system may improve the removal of starch pollutants in wastewater.

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

    Science.gov (United States)

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

    2010-01-01

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

  20. Scale up of ethanol production using pulp mill wastewater sludge by cellulase and saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Kunchada Sangasintu; Petchporn Chawakitchareon

    2010-01-01

    This study aimed to evaluate the potential use of pulp mill wastewater sludge as substrate in ethanol production. The simultaneous saccharification and fermentation process was conducted by using Saccharomyces cerevisiae TISTR 5339 under optimum proportion of cellulase and pulp mill wastewater sludge. The ethanol production from cellulosic materials in simultaneous saccharification and fermentation needs cooperation between cellulase and yeast. The cellulase hydrolyzes cellulose to sugar while yeast utilizes sugar to produce ethanol. The pulp mill wastewater sludge has an average content of 73.3 % hemi cellulose, 67.1 % alpha cellulose, 4.7 % beta cellulose and 1.4 % gamma cellulose. The experimental results indicated that the volume of the ethanol tend to increase with time, providing the maximum ethanol yield of 0.69 g/g on the 7"t"h day, the last day of the experiment. The ethanol production was scaled up in 5 L fermentor under optimum proportion and increased the fermentation period. It was found that the ethanol production gave the maximum ethanol yield of 1.14 g/g on the 9"t"h day of the totally 13 days experimentation. These results showed that the cellulose from pulp mill wastewater sludge was as effective substrate for ethanol production and alternative energy for the future. (author)

  1. Effect of potassium ferrate on disintegration of waste activated sludge (WAS).

    Science.gov (United States)

    Ye, Fenxia; Ji, Haizhuang; Ye, Yangfang

    2012-06-15

    The activated sludge process of wastewater treatment results in the generation of a considerable amount of excess activated sludge. Increased attention has been given to minimization of waste activated sludge recently. This paper investigated the effect of potassium ferrate oxidation pretreatment on the disintegration of the waste activated sludge at various dosages of potassium ferrate. The results show that potassium ferrate pretreatment disintegrated the sludge particle, resulting in the reduction of total solid content by 31%. The solubility (SCOD/TCOD) of the sludge increased with the increase of potassium ferrate dosage. Under 0.81 g/g SS dosage of potassium ferrate, SCOD/TCOD reached 0.32. Total nitrogen (TN) and total phosphorous (TP) concentrations in the solution all increased significantly after potassium ferrate pretreatment. The sludge particles reduced from 116 to 87 μm. The settleability of the sludge (SVI) was enhanced by 17%, which was due to the re-flocculation by the by-product, Fe(III), during potassium ferrate oxidation and the decrease of the viscosity. From the result of the present investigations, it can be concluded that potassium ferrate oxidation is a feasible method for disintegration of excess activated sludge. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Kwon, Tae-Soon; Lee, Jae-Young

    2015-10-01

    Wastewater treatment plants at petroleum refineries often produce substantial quantities of sludge with relatively high concentrations of oil. Disposal of this waste is costly, in part because the high oil content requires use of secure disposal methods akin to handling of hazardous wastes. This article examines the properties of oily sludge and evaluates optional methods for reducing the oil content of this sludge to enable use of lower cost disposal methods. To reduce the oil content or break the structure of oily sludge, preliminary lab-scale experiments involving mechanical treatment, surfactant extraction, and oxidation are conducted. By applying surfactants, approximately 36% to 45% of oils are extracted from oily sludge. Of this, about 33% of oils are rapidly oxidised via radiation by an electron beam within 10 s of exposure. The Fenton reaction is effective for destruction of oily sludge. It is also found that 56% of oils were removed by reacting oily sludge with water containing ozone of 0.5 mg l(-1) over a period of 24 h. Oxidation using ozone thus can also be effectively used as a pretreatment for oily sludge. © The Author(s) 2015.

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

    Science.gov (United States)

    Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł

    2017-02-01

    The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm -3 with the average value at 1.17 kWhm -3 . The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Evaluation of Potentially Harmful Substances in Dried Sludge of Isfahan Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Bijan Bina

    2004-05-01

    Thus, taking into account the potential risks caused by presence of heavy metals in sludge and for the control of processes of sludge treatment and disposal and also protect of environmental health and enhauncement of public health level, specially for farmers and consumers of raw crops, needs sampling and characterization of sludge. In the present research concentration of 11 heavy metals and potentially toxic elements in dried sludge of Isfahan South and North and Shahinshahr wastewater treatment plants were determined using standard methods. Samples have been taken from dried sludge of treatment plants, and been measured after being prepared through atomic absorption apparatus and were compared with EPA enacted standards in regulation 40 CFR part 503. As well, fertilizer value parameters of sludge were measured and were compared with standards and guidelines. The results showed that the average concentration of above elements in all three treatment plants, not exceeded from EPA standards, however, regarding the accumulative property of these elements and lack of necessary protective effects of EPA standards, in using these sludges in the agricultural soils, the necessary caution and care should be taken, in other uses of sludges, however, there is no limitation.

  5. Parameters affecting the degradation of benzothiazoles and benzimidazoles in activated sludge systems

    Energy Technology Data Exchange (ETDEWEB)

    Vos, D de [Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Industrial Microbiology and Biochemistry; Wever, H de [Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Industrial Microbiology and Biochemistry; Verachtert, H [Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Industrial Microbiology and Biochemistry

    1993-07-01

    It was found that benzothiazole, 2-oxybenzothiazole and 2-benzothiazolesulphonate were degraded in activated sludge systems. 2-Mercaptobenzothiazole (MBT) was more resistant, although the first step in MBT degradation seemed to be transformation to the sulphonate form. At higher MBT concentrations, it was transformed into a disulphide, which accumulated in the sludge. MBT was also found to be mainly responsible for the toxicity of rubber chemical waste-water towards activated sludges. It inhibited the degradation of the other heterocycles. Only at concentrations of around 20 ppm was MBT degraded. Mercaptobenzimidazole ranked second in resistance to degradation. (orig.)

  6. Wastewater sludge fertilization: Biomass productivity and heavy metal bioaccumulation in two Salix species grown in southern Quebec (Canada)

    International Nuclear Information System (INIS)

    Teodorescu, T.I.; Labrecque, M.; Daigle, S.; Poisson, G.

    1993-01-01

    More than other kind of trees, fast growing tree species, such as willows, can profit from sludge application. While sludges are good fertilizers, they may also contain heavy metals which could reduce productivity and cause risks to the environment. The main aims of the present research were to study: (1) the production capacity of Salix discolor and Salix viminalis when supplied with various amounts of dried and pelleted sludge; (2) the uptake, and accumulation of heavy metals. Unrooted cuttings were planted on sandy soil in large plastic pots and grown in outdoors for 20-week period. Five doses of sludge were applied: equivalent of 200 (T1), 160 (T2), 120 (T3), 80 (T4) and 40 (T5) kg N per ha. Trees which received the largest amount of sludge showed the best growth results. The stem-branch biomass was significantly higher for Salix viminalis. The relationship between the total yield biomass Y (t/ha) and the rate of fertilization X (kg N/ha) is linear. The regression equations of prediction biomass production were established as following: Salix discolor Y = 1.807 + 0.037X and Salix viminalis Y = 2.578 + 0.042X. For both species, greatest stems-branch biomass per gram of N applied were produced by treatments 1 and 2. The amount of nitrogen per leaf area (N/LA) and per leaf dry weight (N/LW), were higher for Salix viminalis which leads us believe that its photosynthetic activity was better. The transfer coefficient did not vary between the species but was significantly different for Cd and Zn. The plants were able to absorb Cd and Zn but less of Ni, Hg and Cu and Pb. It was concluded that the dried and pelleted sludge can be a good fertilizer. The treatment is beneficial when Salix discolor and particulary Salix viminalis are used as vegetation filters for wastewater sludge purification and production purposes

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    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)

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

    Science.gov (United States)

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

    2012-01-15

    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.

  9. Bacteriological studies on dairy waste activated sludge

    NARCIS (Netherlands)

    Adamse, A.D.

    1966-01-01

    Dairy-waste activated sludge was examined for bacterial composition and response to different conditions. Strains isolated were classified mainly into three groups: predominantly coryneform bacteria (largely Arthrobacter), some Achromobacteraceae and a small groups of Pseudomonadaceae.

  10. Persistent organic pollutants (POPs) in the conventional activated sludge treatment process: fate and mass balance

    International Nuclear Information System (INIS)

    Katsoyiannis, Athanasios; Samara, Constantini

    2005-01-01

    The fate and the mass balance of persistent organic pollutants (POPs) during the conventional activated sludge treatment process were investigated in the wastewater treatment plant of the city of Thessaloniki, northern Greece. The POPs of interest were 7 polychlorinated biphenyls and 19 organochlorine pesticides. Target compounds were determined at six different points across the treatment system: the influent, the effluent of the primary sedimentation tank, the effluent of the secondary sedimentation tank, the primary sludge, the activated sludge from the recirculation stream, and the digested/dewatered sludge. The distribution of POPs between the dissolved and the adsorbed phases of wastewater and sludge was investigated. A good linear relationship between the distribution coefficients, K d , and the octanol-water partition coefficients, K ow , of the solutes was observed only in raw wastewater, suggesting that other factors affect the phase distribution of organic compounds in treated wastewater. For all POPs, a significant increase in partitioning with a decreasing solids concentration was observed, revealing an effect from non-settling microparticles remaining in the 'dissolved' phase during the separation procedure. A good linear relationship was also revealed between logK d and the dissolved organic carbon (DOC) content of wastewater, suggesting that DOC favors the advective transport of POPs in the dissolved phase. Almost all POPs showed good mass balance agreements at both the primary and the secondary treatment. The losses observed for some species could be attributed to biodegradation/biotransformation rather than volatilization. The relative distribution between the treated effluent and the waste sludge streams varied largely among different compounds, with p-p'-DDE being highly accumulated in the waste sludge (98%) but almost 60% of α-HCH remaining in the treated effluent

  11. Modeling Aspects Of Activated Sludge Processes Part I: Process Modeling Of Activated Sludge Facilitation And Sedimentation

    International Nuclear Information System (INIS)

    Ibrahim, H. I.; EI-Ahwany, A.H.; Ibrahim, G.

    2004-01-01

    Process modeling of activated sludge flocculation and sedimentation reviews consider the activated sludge floc characteristics such as: morphology viable and non-viable cell ratio density and water content, bio flocculation and its kinetics were studied considering the characteristics of bio flocculation and explaining theory of Divalent Cation Bridging which describes the major role of cations in bio flocculation. Activated sludge flocculation process modeling was studied considering mass transfer limitations from Clifft and Andrew, 1981, Benefild and Molz 1983 passing Henze 1987, until Tyagi 1996 and G. Ibrahim et aI. 2002. Models of aggregation and breakage of flocs were studied by Spicer and Pratsinis 1996,and Biggs 2002 Size distribution of floes influences mass transfer and biomass separation in the activated sludge process. Therefore, it is of primary importance to establish the role of specific process operation factors, such as sludge loading dynamic sludge age and dissolved oxygen, on this distribution with special emphasis on the formation of primary particles

  12. Modeling of Activated Sludge Floc Characteristics

    OpenAIRE

    Ibrahim H. Mustafa; G. Ibrahim; Ali Elkamel; A. H. Elahwany

    2009-01-01

    Problem Statement: The activated sludge system needs to improve the operational performance and to achieve more effective control. To realize this, a better quantitative understanding of the biofloc characteristics is required. The objectives of this study were to: (i) Study the biofloc characteristics from kinetics-mass transfer interaction point of view by quantification of the weight of the aerobic portion of the activated sludge floc to the total floc weight. (ii) Study the effect of bulk...

  13. Inactivation of poliovirus in wastewater sludge with radiation and thermoradiation

    International Nuclear Information System (INIS)

    Ward, R.L.

    1977-01-01

    The effect of sludge on the rate of viral inactivation by radiation and thermoradiation was determined. The virus used for the experiments was the poliovirus type 1 strain CHAT, which was grown in HeLa cells. Radiation, heat, and thermoradiation treatments were carried out in a chamber specifically designed to permit rapid heating and cooling of the samples at the beginning and completion of treatment, respectively. The treated samples were then assayed for plaque-forming units on HeLa cells after sonication in 0.1% sodium dodecylsulfate (SDS). For the radiation treatment virus was diluted 10-fold into PBS containing new sludge, irradiated at 20 0 C with 137 Cs at a dose rate of 30 krads/min, and assayed for infectious virus. The results show that raw sludge is protective of poliovirus against ionizing radiation but that small concentrations of sludge are nearly as protective as large concentrations. When heat and radiation are given simultaneously, however, the amount of protection afforded by sludge is less than the additive effects of the individual treatments. This result is especially evident at low concentrations of sludge. It appears, therefore, that thermoradiation treatment may be an effective way of inactivation viruses in waters containing low concentrations of suspended solids

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

    KAUST Repository

    Xue, Jinkai

    2011-07-01

    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

  15. Reuse of wastewater sludge with marine clay as a new resource of construction aggregates.

    Science.gov (United States)

    Tay, J H; Show, K Y; Lee, D J; Hong, S Y

    2004-01-01

    The disposal of sludge from wastewater treatment presents highly complex problems to any municipality. Most of the sludge disposal methods have varying degrees of environmental impact. Hence, it is necessary to explore potential areas of reuse in order to alleviate sludge disposal problems and to conserve natural resources. Industrial sludge and marine clay are two forms of high-volume wastes. Using these wastes as a resource of raw materials to produce construction aggregates would enable large-scale sludge reuse. The aggregates were produced at various sludge-clay combinations containing 0, 20, 50, 80 and 100% clay contents, respectively. The pelletized aggregates displayed lower particle densities ranged between 1.48 and 2.25 g/cm3, compared to the density of granite at 2.56 g/cm3. Good 28-day concrete compressive strength of 38.5 N/mm2 achieved by the 100% sludge aggregate was comparable to the value of 38.0 N/mm2 achieved of the granite control specimens. The leachate contamination levels from the aggregates after 150 days were found acceptable when used in concrete, indicating insignificant environmental contamination. The heat flow study showed increases in heat flow at the temperatures of 480 degrees C and between 660 degrees C and 900 degrees C, indicating a need for the extension of heating time around these temperatures.

  16. Influence of process operating parameters on dryness level and energy saving during wastewater sludge electro-dewatering.

    Science.gov (United States)

    Mahmoud, Akrama; Hoadley, Andrew F A; Conrardy, Jean-Baptiste; Olivier, Jérémy; Vaxelaire, Jean

    2016-10-15

    Electrically assisted mechanical dewatering, known as electro-dewatering (EDW), is an alternative emerging technology for energy-efficient liquid/solids separation in the dewatering of wastewater sludge. In this study, the performance of the electro-dewatering (EDW) process for activated wastewater sludge was investigated. The influence of the operating modes; being the timing of voltage (U-EDW) or current (I-EDW) application to either or both the filtration and compression stages, and the influence of the applied pressure (in successive 30 min pressure steps) were studied. The results showed that by delaying the application of the electric field to the filter cake compression stage, there was a potential saving in power consumption of around 10-12% in the case of U-EDW and about 30-46% in the case of I-EDW. The increase of the applied pressure from 0.5 to 12 bar during the filter cake compression stage leads to an increase in electro-dewatering kinetics. The results also reveal that at a low electric field level the increase of the processing pressure has a relatively pronounced effect on the dewatering process. At high levels of the electric field, a minimum processing pressure (4-6 bar) is required to improve the electrical contact between the electrode and the sludge and thus lower the energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Extraction solvent’s effect on biogas production from mixtures of date seed and wastewater sludge

    Directory of Open Access Journals (Sweden)

    Radeef Wameed

    2017-01-01

    Full Text Available The objective of this study was to evaluate the impact of extraction solvent on biogas production from mixtures of date (Phoenix dactylifera seed and wastewater treatment sludge. Date palm seed is a locally produced waste which is used in different useful purposes. Date seed is rich in proteins, carbohydrates and lipids and have the potential for biogas enhancement. In this study, three extraction solvents, hexane, ethyl acetate and Ethanol:water (1:1, were used on two types of date seeds (locally known as Khalas and Khudari. Date seed powder of size 0.425 – 0.6 mm after extraction was mixed with wastewater treatment sludge at dry date seed/dry sludge solids ratios of 0%, 10%, 20%, 40%, 60%, and 80%. The study showed a direct relationship between biogas production and ratio of date seeds/wastewater sludge in the mixture. Furthermore, the results confirmed that the quantity of biogas produced from samples containing raw date seed was almost same as the quantity produced from samples containing date seed after extraction. The results revealed that the used extraction solvents had no effect on biogas production

  18. Biopolymer Production Kinetics of Mixed Culture Using Wastewater Sludge as a Raw Material and the Effect of Different Cations on Biopolymer Applications in Water and Wastewater Treatment.

    Science.gov (United States)

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

    2016-05-01

    Thirteen extracellular polymeric substances (EPS) producing bacterial strains were cultivated (as mixed culture) in the sterilized sludge (suspended solids of 25 g/L) and the batch fermentation was carried out. Mixed culture revealed a high specific growth rate of 0.35/hr. The EPS production rate was higher up to 24 hours, which gradually decreased with further incubation. The kinetic estimates demonstrated growth-associated EPS production. Broth EPS revealed higher flocculation activity when combined with different cations (Ca(2+), Mg(2+), Fe(3+), and Al(3+)) in river water (≥90%), municipal wastewater (≥90%), and brewery wastewater (≥80%), respectively. A low dose (5 to 40 mg/L) of trivalent cations was required to achieve higher flocculation compared to the divalent cations (50 to 250 mg/L). Flocculation performance of EPS was comparable to Magnafloc-155 (chemical polymer) and, hence, it could be used as a flocculant.

  19. Thermal activation of an industrial sludge for a possible valorization

    Directory of Open Access Journals (Sweden)

    Lamrani Sanae

    2014-04-01

    Full Text Available This work fits within the framework of sustainable management of sludge generated from wastewater treatment in industrial network. The studied sludge comes from an industry manufacturing sanitary ware products.Physico-chemical and mineralogical characterization was performed to give an identity card to the sludge. We noted the absence of metal pollution.The industrial sludge has been subjected to thermal activation at various temperatures (650°C to 850°C. The pozzolanic activity was evaluated by physico- chemical and mechanical methods [1]. Pozzolanicity measurement was carried out based on Chapelle test and conductivity revealed the existence of pozzolanic properties of the calcined samples. The best pozzolanic reactivity was obtained for the sample calcined at 800°C. We noticed a decrease in the reactivity of the sample calcined at 850°C. In addition, analysis by means of X-ray diffraction and Fourier transform infrared spectroscopy showed that sludge recrystallization begins at a temperature of 850°C. Pozzolanicity index of the thermally treated samples was determined by measuring the mechanical resistance of mortar specimens previously kept in a saturated lime solution for 28 days (ASTM C618 [2]. The best pozzolanic activity index was obtained for the sample calcined at 800°C (109.1%.This work is a contribution to the research for new supplying sources of raw materials and additives in the field of construction. It presents a proposition of a promising solution for the valorization of waste material as an additive instead of being discharged into open air dumps causing a major environmental problem.

  20. Solidifications of wastewater sludge from nuclear power stations

    International Nuclear Information System (INIS)

    Hanzlicek, T.; Steinerova, M.; Perna, L.; Straka, P.

    2006-01-01

    Our task was to incorporate wastewater slag containing 30 wt. % and 60 wt. % water into a geopolymer matrix and encapsulate the mixture of materials into an inorganic polymer network. Prepared from activated kaolinitic clay by reaction with alkali aqueous solution. the geopolymer matrix accepts different types of inorganic materials, such as quartz, mica and limestone, in its formatted network. The geopolymer matrix also encapsulates and inhibits metals, including radioactive ones. By using the radioactive slag as the filler of a geopolymer matrix, the slag can be solidified in the form of a stable insoluble material suitable for storage. Application as a geopolymer matrix is an economic way to use the enormous quantities of waste clays emerging from industrial production. A cheap primary raw material and lower energy demands in comparison with the activation of clay with cement fabrication is one of the advantages of the geopolymer matrix. The only problem to resolve is the high quantities of water (60 wt. %), which must be reduced by using an additional inorganic filler (other type of waste could be used). In that moment the content of inhibited slag is lowered and recalculation in dry slug does not exceed 15 wt. %. The result of compression resistance is better than 10 MPa and leaching tests did not give any results exceeding the standards

  1. Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

    Directory of Open Access Journals (Sweden)

    Hong Chen

    Full Text Available The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS, play vital roles in the normal operation of wastewater treatment plants (WWTPs. The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm, but different observation were made at higher CuNPs concentrations (30 and 50 ppm. At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

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

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Christensen, Thomas Højlund; Guildal, T.

    2015-01-01

    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...... on the assessment, it is evident that both inorganic and organic elements accumulated in the sewage sludge, with the exception of elements that are highly soluble or degradable by wastewater and sludge treatment processes. The majority of metals and metalloids were further accumulated in the incineration ash, while...

  3. Effects of wastewater sludge and its detergents on the stability of rotavirus

    Energy Technology Data Exchange (ETDEWEB)

    Ward, R.L. (Sandia Labs., Albuquerque, NM); Ashley, C.S.

    1980-06-01

    Wastewater sludge reduced the heat required to inactivate rotavirus SA-11, and ionic detergents were identified as the sludge components responsible for this effect. A similar result was found previously with reovirus. The quantitative effects of individual ionic detergents on rotavirus and reovirus were very different, and rotavirus was found to be extremely sensitive to several of these detergents. However, neither virus was destabilized by nonionic detergents. On the contrary, rotavirus was stabilized by a nonionic detergent against the potent destabilizing effects of the ionic detergent sodium dodecyl sulfate. The destabilizing effects of both cationic and anionic detergents on rotavirus were greatly altered by changes in the pH of the medium.

  4. 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.

    2007-01-01

    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

  5. Degradation of triclosan and triclocarban and formation of transformation products in activated sludge using benchtop bioreactors

    Science.gov (United States)

    Benchtop bioreactors were run aerobically with activated sludge samples collected from a large municipal wastewater treatment plant (WWTP) to understand how increased hydraulic retention time (HRT) and varying treatment temperatures (21°C and 30°C) impact concentrations of the endocrine disrupting a...

  6. Storage and degradation of poly-ß-hydroxybutyrate in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Dircks, Klaus; Henze, Mogens; van Loosdrecht, M.C.M.

    2001-01-01

    This research analyses the accumulation and degradation of poly-b-hydroxybutyrate (PHB) in experiments with pulse addition of acetate to samples of activated sludge from pilot-plant and full-scale wastewater treatment plants. The experiments are divided into two periods: a feast period defined as...

  7. Factors influencing sorption of ciprofloxacin onto activated sludge: Experimental assessment and modelling implications

    DEFF Research Database (Denmark)

    Polesel, Fabio; Lehnberg, Kai; Dott, Wolfgang

    2015-01-01

    was registered under anaerobic conditions. The activated sludge model for xenobiotics (ASM-X) was extended with Freundlich-based sorption kinetics and used to predict the fate of ciprofloxacin in a wastewater treatment plant (WWTP). Scenario simulations, using experimental Freundlich parameters, were used...

  8. Micropollutant degradation via extracted native enzymes from activated sludge.

    Science.gov (United States)

    Krah, Daniel; Ghattas, Ann-Kathrin; Wick, Arne; Bröder, Kathrin; Ternes, Thomas A

    2016-05-15

    A procedure was developed to assess the biodegradation of micropollutants in cell-free lysates produced from activated sludge of a municipal wastewater treatment plant (WWTP). This proof-of-principle provides the basis for further investigations of micropollutant biodegradation via native enzymes in a solution of reduced complexity, facilitating downstream protein analysis. Differently produced lysates, containing a variety of native enzymes, showed significant enzymatic activities of acid phosphatase, β-galactosidase and β-glucuronidase in conventional colorimetric enzyme assays, whereas heat-deactivated controls did not. To determine the enzymatic activity towards micropollutants, 20 compounds were spiked to the cell-free lysates under aerobic conditions and were monitored via LC-ESI-MS/MS. The micropollutants were selected to span a wide range of different biodegradabilities in conventional activated sludge treatment via distinct primary degradation reactions. Of the 20 spiked micropollutants, 18 could be degraded by intact sludge under assay conditions, while six showed reproducible degradation in the lysates compared to the heat-deactivated negative controls: acetaminophen, N-acetyl-sulfamethoxazole (acetyl-SMX), atenolol, bezafibrate, erythromycin and 10,11-dihydro-10-hydroxycarbamazepine (10-OH-CBZ). The primary biotransformation of the first four compounds can be attributed to amide hydrolysis. However, the observed biotransformations in the lysates were differently influenced by experimental parameters such as sludge pre-treatment and the addition of ammonium sulfate or peptidase inhibitors, suggesting that different hydrolase enzymes were involved in the primary degradation, among them possibly peptidases. Furthermore, the transformation of 10-OH-CBZ to 9-CA-ADIN was caused by a biologically-mediated oxidation, which indicates that in addition to hydrolases further enzyme classes (probably oxidoreductases) are present in the native lysates. Although the

  9. Concomitant degradation of bisphenol A during ultrasonication and Fenton oxidation and production of biofertilizer from wastewater sludge.

    Science.gov (United States)

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

    2011-09-01

    Degradation of bisphenol A (BPA), an endocrine disruptor, from wastewater sludge (WWS) has attracted great interest recently. In the present study, the effects of different pre-treatment methods, including ultrasonication (US), Fenton's oxidation (FO) and ferro-sonication (FS) was assessed in terms of increase in solubilization of WWS and simultaneous degradation of BPA. Among US, FO and FS pre-treatment, higher suspended solids (SS), volatile suspended solids (VSS), chemical oxygen demand (COD) and soluble organic carbon (SOC) solubilization (39.7%, 51.2%, 64.5% and 17.6%, respectively) was observed during a ferro-sonication pre-treatment process carried out for 180 min, resulting in higher degradation of BPA (82.7%). In addition, the effect of rheological parameters (viscosity and particle size) and zeta potential on the degradation of BPA in raw and different pre-treated sludges were also investigated. The results showed that a decrease in viscosity and particle size and an increase in zeta potential resulted in higher degradation of BPA. BPA degradation by laccases produced by Sinorhizobium meliloti in raw and pre-treated sludge was also determined. Higher activity of laccases (207.9 U L(-1)) was observed in ferro-sonicated pre-treated sludge (180 min ultrasonic time), resulting in higher removal of BPA (0.083 μg g(-1)), suggesting concomitant biological degradation of BPA. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Gamma irradiation induced disintegration of waste activated sludge for biological hydrogen production

    International Nuclear Information System (INIS)

    Yin, Yanan; Wang, Jianlong

    2016-01-01

    In this paper, gamma irradiation was applied for the disintegration and dissolution of waste activated sludge produced during the biological wastewater treatment, and the solubilized sludge was used as substrate for bio-hydrogen production. The experimental results showed that the solubilization of waste activated sludge was 53.7% at 20 kGy and pH=12, and the SCOD, polysaccharides, protein, TN and TP contents in the irradiated sludge solutions was 3789.6 mg/L, 268.3 mg/L, 1881.5 mg/L, 132.3 mg/L and 80.4 mg/L, respectively. The irradiated sludge was used for fermentative hydrogen production, and the hydrogen yield was 10.5±0.7 mL/g SCOD consumed . It can be concluded that the irradiated waste activated sludge could be used as a low-cost substrate for fermentative hydrogen production. - Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • The hydrogen yield was 10.5±0.7 mL/g SCOD consumed .

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

    Directory of Open Access Journals (Sweden)

    Tohru Suzuki

    2012-12-01

    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.

  12. Synergetic pretreatment of waste activated sludge by hydrodynamic cavitation combined with Fenton reaction for enhanced dewatering.

    Science.gov (United States)

    Cai, Meiqiang; Hu, Jianqiang; Lian, Guanghu; Xiao, Ruiyang; Song, Zhijun; Jin, Micong; Dong, Chunying; Wang, Quanyuan; Luo, Dewen; Wei, Zongsu

    2018-04-01

    The dewatering of waste activated sludge by integrated hydrodynamic cavitation (HC) and Fenton reaction was explored in this study. We first investigated the effects of initial pH, sludge concentration, flow rate, and H 2 O 2 concentration on the sludge dewaterability represented by water content, capillary suction time and specific resistance to filtration. The results of dewatering tests showed that acidic pH and low sludge concentration were favorable to improve dewatering performance in the HC/Fenton system, whereas optimal flow rate and H 2 O 2 concentration applied depended on the system operation. To reveal the synergism of HC/Fenton treatment, a suite of analysis were implemented: three-dimensional excitation emission matrix (3-DEEM) spectra of extracellular polymeric substances (EPS) such as proteins and polysaccharides, zeta potential and particle size of sludge flocs, and SEM/TEM imaging of sludge morphology. The characterization results indicate a three-step mechanism, namely HC fracture of different EPS in sludge flocs, Fenton oxidation of the released EPS, and Fe(III) re-flocculation, that is responsible for the synergistically enhanced sludge dewatering. Results of current study provide a basis to improve our understanding on the sludge dewatering performance by HC/Fenton treatment and possible scale-up of the technology for use in wastewater treatment plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

    Science.gov (United States)

    Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

    2010-01-01

    The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

  14. Enzyme Activities in Waste Water and Activated Sludge

    DEFF Research Database (Denmark)

    Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

    1992-01-01

    The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

  15. Treating ammonium-rich wastewater with sludge from water treatment plant to produce ammonium alum

    Directory of Open Access Journals (Sweden)

    Wen-Po Cheng

    2016-03-01

    Full Text Available This study applies a process to treat ammonium-rich wastewater using alum-generated sludge form water purification plant, and gain economic benefit by producing ammonium alum (Al(NH4(SO42·12H2O. The factors affecting production of ammonium alum include molar ratio of ammonium to aluminum concentration, sulfuric acid concentration, mixing speed, mixing time, standing time, and temperature. According to the equation for the ammonium removal reaction, the theoretical quantity of ammonium alum was calculated based on initial and final concentrations of ammonium. Then, the weight of ammonium alum crystal was divided by the theoretical weight to derive the recovery ratio. The optimum sludge and sulfuric acid dosage to treat about 17 g L−1 ammonium wastewater are 300 g L−1 and 100 mL L−1, respectively. The optimal dosage for wastewater is molar ratio of ammonium to aluminum of about 1 due to the aluminum dissolving in acidified wastewater. The ammonium removal efficiency is roughly 70% and the maximum recovery ratio for ammonium alum is 93% when the wastewater is mixed for 10 min at the mixing velocity gradient of 100 s−1. Ammonium alum production or ammonium removal can be enhanced by controlling the reaction at low temperatures.

  16. Performance of Submerged Aerated Biofilters for Wastewater Treatment and Excess Biological Sludge Production

    Directory of Open Access Journals (Sweden)

    Mohammad A. Baghapour

    2007-01-01

    Full Text Available Minimizing sludge production in the treatment facility is a reasonable measure to reduce waste in sewage treatment, especially as regards excess biological sludge. In this regard, submerged aerated filters' (SAFs have recently found increasing applications in treatment facilities. Thanks to their treatment mechanism, they have greatly contributed to reduction of waste production and, thereby, to reduced treatment costs. Biomass growths of both attached and suspended types take place in these filters. However, little attention has been paid to suspended sludge production and to its relationship with the physical properties of the filter. The design and application criterion for these filters is the organic loadings on unit of area or unit of volume of the media used in these filters. In this study, four filters with different physical properties and different specific areas were loaded with synthetic wastewater made of low-fat dry milk powder for five different hydraulic retention times to evaluate excess sludge production rates in submerged aerated filters. It was shown that increasing specific area increased SCOD removal efficiency up to a maximum level in saturated growths after which point the removal efficiency remained unchanging or decreased. The results also revealed that decreased hydraulic retention times increased sludge production rates in all the study columns and that media with higher porosity levels produced less excess sludge despite lower pollutant removal efficiency.

  17. PBDEs versus NBFR in wastewater treatment plants: occurrence and partitioning in water and sludge

    Directory of Open Access Journals (Sweden)

    Joyce Cristale

    2015-06-01

    Full Text Available This study evaluates the occurrence of flame retardants (FR in five wastewater treatment plants (WWTPs located close to Barcelona (NE Spain, an area with high urban and industrial pressures. Compounds studied include eight polybromodiphenyl ethers (PBDEs and eight New Brominated Flame Retardants (NBFRs, for which little information regarding their presence, partitioning and fate within the WWTPs is available. In unfiltered influent samples, PBDEs were not detected and bis(2-ethyl-1-hexyltetrabromophthalate was the only NBFR detected, and all WWTPs were efficient in eliminating this compound as no residues were found in the effluents. However, primary sludge contained from 279 to 2299 ng/g dry weight of ΣFR and the concentration increased in secondary (biological sludge. NBFRs accounted for the main FR detected in sludge, representing a 63-97% of the total load, and among PBDEs, BDE-209 was the most ubiquitous congener. Considering the amount of sludge generated in each WWTP, it was estimated that 0.34-17.2 kg of FR are released annually through the sludge, which can have negative environmental and health implications if sludge is used as biosolid in agriculture. Overall, this study provides a sampling design and analytical protocol to be used to determine the evolution of FR in WWTPs and compares the levels detected, considering that PBDEs are being phased out to be substituted by other compounds which also have high accumulative and recalcitrant properties.

  18. The study of leachability and toxicity of sludge after neutralization of Saraka and Robule AMD wastewaters

    Directory of Open Access Journals (Sweden)

    Gardić Vojka

    2017-01-01

    Full Text Available Acid mine drainage (AMD waters are one of the most important ecological risks at the global level because of its high heavy metals content and strong acidity. Treatment of AMD water is a complex and expensive. One of the most widely used treatment process is the neutralization process of AMD. The result of neutralization is the production of sludge which may contain various other (heavy metals, depending on the chemical characteristics of the mine water treated. In this paper, leachability and toxicity of the sludges obtained during the neutralization process of wastewater from Saraka and Robule acid mine drainage and the sludges after the stabilization process at different temperatures is tested. Sludge produced in the neutralization process of Robule AMD R4 (40 and stabilized on 105°C and 200°C shows a H8-corrosiveness characteristic. Stabilized sludge show tendency to lower leachability of zinc and copper, but without influence on sulphate leachability. Sludges that show a H8-corrosiveness needs additional stabilization/neutralization pretreatment prior temperature treatment.

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

    International Nuclear Information System (INIS)

    Orozco, A. Micaela Ferro; Contreras, Edgardo M.; Zaritzky, Noemi E.

    2008-01-01

    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

  20. Anaerobic biodegradability essays from brewery wastewater using granular and flocculent sludges

    Directory of Open Access Journals (Sweden)

    C J Collazos Chávez

    2003-01-01

    Full Text Available At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of the sludges used in the systems. It also looks to analyze other associated factors such as: waste, characteristics, operation conditions and design parameters. The investigation was conducted in two phases using granular and floculent sludges. This method was used for determining the anaerobic biodegradability of wastewater from two industrial plants.

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

    Directory of Open Access Journals (Sweden)

    Nugul Intrasungkha

    2008-04-01

    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.

  2. 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

    2012-10-01

    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

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

    Directory of Open Access Journals (Sweden)

    Chunyan Chai

    2015-03-01

    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

  4. 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)

    2016-09-01

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

  5. THE CONCENTRATION OF TRACE ELEMENTS IN SEWAGE SLUDGE FROM WASTEWATER TREATMENT PLANT IN GNIEWINO

    Directory of Open Access Journals (Sweden)

    Julita Karolina Milik

    2017-09-01

    Full Text Available Sewage sludge originated from wastewater treatment plants (WWTP serving rural areas are suggested for agricultural or natural usage. Before, however, sewage sludge is subjected to the several pre-treatments, which involve stabilization, hygienisation and pre-composting. These methods decrease mainly the amount of organic substances and presence of microorganisms, but hardly affects concentrations of heavy metals. The advantages of using sludges as fertilizer for improving and sustaining soil fertility and crop production are many. The addition of sewage sludge to soils could affect potential availability of heavy metals. Trace elements are distributed in the soil in various forms: solid phases, free ions in soil solution, soluble organic-mineral complexes, or adsorbed on colloidal particles. In the study the concentrations of trace elements (Pb, Cd, Cr, Hg, Ni, Zn, Al, As, Se, B, Ba, Br, Ca, Cu, Fe, Mn, Na, Ga, Li, Mo, Sr, Mg, K, Ru, Tl, V, U was tested in sewage sludge obtained from (WWTP serving rural areas (PE< 9 000. In each case, the tested sewage sludge was meeting the criteria of stabilization and was used for agriculture and land reclamation purpose. All the samples were collected in 2016 and were subjected to microwave mineralization in a closed system in aqua regia. The total amound of macro and microelements were determined with a ICP-OES. It was found that the total concentrations of trace metals in all of sewage sludge are the same than Polish regulation limit of pollutants for sludge to be used in agriculture. The trace elements (cadmium: 1,16 mg·kg-1/d.m. in polish sewage sludge, respectively, much higher than those in the other countries. As a most prevalent copper and zinc were observed (111,28 mg·kg-1/d.m. and 282,94 mg·kg-1/d.m.. The concentrations of copper in polish sewage sludge are much lower (49-130 mg·kg-1/d.m. than european sewage sludge (522-562 mg·kg-1/d.m.. The two out of tested heavy metals (beryllium, bismuth

  6. Modelling of sludge blanket height and flow pattern in UASB reactors treating municipal wastewater

    International Nuclear Information System (INIS)

    Singh, K.S.; Viraraghavan, T.

    2002-01-01

    Two upflow anaerobic sludge blanket (UASB) reactors were started-up and operated for approximately 900 days to examine the feasibility of treating municipal wastewater under low temperature conditions. A modified solid distribution model was formulated by incorporating the variation of biogas production rate with a change in temperature. This model was used to optimize the sludge blanket height of UASB reactors for an effective operation of gas-liquid-solid (GLS) separation device. This model was found to simulate well the solid distribution as confirmed experimental observation of solid profile along the height of the reactor. Mathematical analysis of tracer curves indicated the presence of a mixed type of flow pattern in the sludge-bed zone of the reactor. It was found that the dead-zone and by-pass flow fraction were impacted by the change in operating temperatures. (author)

  7. Kinetic model of excess activated sludge thermohydrolysis.

    Science.gov (United States)

    Imbierowicz, Mirosław; Chacuk, Andrzej

    2012-11-01

    Thermal hydrolysis of excess activated sludge suspensions was carried at temperatures ranging from 423 K to 523 K and under pressure 0.2-4.0 MPa. Changes of total organic carbon (TOC) concentration in a solid and liquid phase were measured during these studies. At the temperature 423 K, after 2 h of the process, TOC concentration in the reaction mixture decreased by 15-18% of the initial value. At 473 K total organic carbon removal from activated sludge suspension increased to 30%. It was also found that the solubilisation of particulate organic matter strongly depended on the process temperature. At 423 K the transfer of TOC from solid particles into liquid phase after 1 h of the process reached 25% of the initial value, however, at the temperature of 523 K the conversion degree of 'solid' TOC attained 50% just after 15 min of the process. In the article a lumped kinetic model of the process of activated sludge thermohydrolysis has been proposed. It was assumed that during heating of the activated sludge suspension to a temperature in the range of 423-523 K two parallel reactions occurred. One, connected with thermal destruction of activated sludge particles, caused solubilisation of organic carbon and an increase of dissolved organic carbon concentration in the liquid phase (hydrolysate). The parallel reaction led to a new kind of unsolvable solid phase, which was further decomposed into gaseous products (CO(2)). The collected experimental data were used to identify unknown parameters of the model, i.e. activation energies and pre-exponential factors of elementary reactions. The mathematical model of activated sludge thermohydrolysis appropriately describes the kinetics of reactions occurring in the studied system. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Effects of nickel(II) addition on the activity of activated sludge microorganisms and activated sludge process

    International Nuclear Information System (INIS)

    Ong, Soon-An; Toorisaka, Eiichi; Hirata, Makoto; Hano, Tadashi

    2004-01-01

    The effects of Ni(II) in a synthetic wastewater on the activity of activated sludge microorganisms and sequencing batch reactor (SBR) treatment process were investigated. Two parallel lab-scale SBR systems were operated. One was used as a control unit, while the other received Ni(II) concentrations equal to 5 and 10 mg/l. The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE modes in the time ratio of 0.5:3.5:1.0:0.75:0.25 for a cycle time of 6 h. The addition of Ni(II) into SBR system caused drastically dropped in TOC removal rate (k) and specific oxygen uptake rate (SOUR) by activated sludge microorganisms due to the inhibitory effects of Ni(II) on the bioactivity of microorganisms. The addition of 5 mg/l Ni(II) caused a slight reduction in TOC removal efficiency, whereas 10 mg/l Ni(II) addition significantly affected the SBR performance in terms of suspended solids and TOC removal efficiency. Termination of Ni(II) addition led to almost full recovery of the bioactivity in microorganisms as shown in the increase of specific oxygen uptake rate (SOUR) and SBR treatment performance

  9. Influence of chemical sprinkle on the processes in activated tank of wastewater treatment

    Directory of Open Access Journals (Sweden)

    Milan Búgel

    2012-12-01

    Full Text Available The research deals with processes occurring in the activation tank during the snow-melt inflow of chemical component of roadsalt. Chemical composition of the suspension in the activation tank is changing following the metabolism of organisms and chemicalcomposition of the influent wastewater. Sludge and wastewater in nitrification tail of the activation tank has higher conductivity, highercontents of chloride, higher sludge index and other characteristics are changing during snow – melt. The amount of the inflow road saltis a determining factor of lyses of microorganism cells.

  10. The challenge of analyzing beta-blocker drugs in sludge and wastewater.

    Science.gov (United States)

    Scheurer, Marco; Ramil, Maria; Metcalfe, Chris D; Groh, Stefanie; Ternes, Thomas A

    2010-01-01

    In this study, different approaches were used to assess and overcome the severe effects of interference from the sample matrix from different types of sludges and wastewater on the analysis of nine beta-blockers and the beta sympathomimetic clenbuterol. The partitioning of the target compounds into sludge was investigated in wastewater treatment plants (WWTPs) in both Canada and Germany to evaluate whether this is an important mechanism for removal from sewage. Due to ion suppression in the electro spray interface, absolute recoveries were for certain compounds even lower than 20%. By using surrogate standards, acceptable relative recoveries of >75% were achieved for WWTP influents and effluents and for sludges. These matrix effects underline the need to use appropriate surrogate standards to aid in analyte quantitation. Using the developed methods, beta-blockers were detected at concentrations up to 2 microg/L in WWTP effluents, with metoprolol, sotalol, and atenolol present as the dominant compounds. Removal rates within WWTPs were highly inconsistent and ranged from 1-69%. Propranolol showed the greatest degree of partitioning into sludge with solid/water partition coefficients of one order of magnitude higher than those for all other compounds. However, even for propranolol, sorption did not contribute significantly to the overall elimination in WWTPs. It is likely that the removal of beta-blockers during waste water treatment can be attributed primarily to microbial biodegradation.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  12. Optimization of polyhydroxylalkanoates production from excess activated sludge

    International Nuclear Information System (INIS)

    Chua, H.; Yu, P.H.F.; Ma, C.K.

    2000-01-01

    Polyhydroxy alkanoates (PHAS) produced by microbial fermentation are biodegradable and can be used as environmentally-friendly substitutes for conventional plastics to resolve the environmental problems associated with plastics wastes. However, widespread applications of PHA are hampered by high production cost. In this study, activated sludge bacteria from a conventional wastewater treatment process were induced, by controlling the carbon-nitrogen (C:N) ratio in the reactor liquor, to accumulate PHA as a low-cost source of biodegradable plastic. Specific polymer yield increased to a maximum of O.27 g polymer/g dry cell mass when the C:N ratio was increased from 24 to 144, whereas specific growth yield decreased with increasing C:N ratio. An optimum C:N ratio of 96 provided the highest overall polymer production yield of 0.09 g polymer/g carbonaceous substrate consumed. Moreover, an intermittent nitrogen feeding program was established to further optimize the polymer volumetric productivity. The overall polymer production yield of O.11 g polymer/g carbonaceous substrate consumed was achieved under C:N ratio of 96 by feeding nitrogen in the reactor liquor once every 4 cycles. While reducing the production costs of biodegradable plastics, this technique also reduced the amount of excess sludge generated from the wastewater treatment process as the polymer portion of biomass was extracted for use. (Author)

  13. Sequencing Batch Reactor and Bacterial Community in Aerobic Granular Sludge for Wastewater Treatment of Noodle-Manufacturing Sector

    OpenAIRE

    Tang Thi Chinh; Phung Duc Hieu; Bui Van Cuong; Nguyen Nhat Linh; Nguyen Ngoc Lan; Nguyen Sy Nguyen; Nguyen Quang Hung; Le Thi Thu Hien

    2018-01-01

    The sequencing batch reactor (SBR) has been increasingly applied in the control of high organic wastewater. In this study, SBR with aerobic granular sludge was used for wastewater treatment in a noodle-manufacturing village in Vietnam. The results showed that after two months of operation, the chemical oxygen demand, total nitrogen and total phosphorous removal efficiency of aerobic granular SBR reached 92%, 83% and 75%, respectively. Bacterial diversity and bacterial community in wastewater ...

  14. Optimization of activated carbon from sewage sludge using response surface methodology

    International Nuclear Information System (INIS)

    Muhammad Salleh Abustan; Hamidi Abdul Aziz; Mohd Azmier Ahmad

    2010-01-01

    Wastewater sludge cake was used to prepare activated carbon using physical activation method. The effects of three preparation variables; the activation temperature, activation time and carbon dioxide gas flow rate on chemical oxygen demand (COD) and ammonia removal from leachate solutions were investigated. Based on the central composite design (CCD), two quadratic models were developed to correlate the preparation variables to the COD and ammonia removal. From the analysis of variance (ANOVA), the significant factors on each experimental design response were identified. The optimum activated carbon prepared from wastewater sludge cake was obtained by using activation temperature of 510 degree Celsius, activation time of 30 min and carbon dioxide flow rate of 500 ml/ min. The optimum activated carbon showed COD and ammonia removal of 26 and 13 %, respectively. (author)

  15. Presence of helminth eggs in wastewater sludge; Presencia de huevos de helmintos en fangos de depuracion de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    GeovanPerez Ortiz, O. G.; Gomez Vera, D. [Estacion Depuradora de Aguas Residuales. Alboraia. Valencia (Spain); Faubell Brell, M. [Universidad de Valencia (Spain); Morenilla Martinez, J. J.; Bernacer Bonora, I. [Entididad Publica de Saneamiento. Valencia (Spain); Bernabeu Adrian, A. [S. A. Agricultures de la Vega. Valencia (Spain); Amores Blasco, S. [Depuracion de Aguas del Mediterraneo. Valencia (Spain)

    2000-07-01

    Land application is one of the best options for the elimination of wastewater sludge, because sludge is useful as conditioner and fertilizer in soils. However, land application represents a sanitary hazards due to the sludge's content in pathogenic agents. Helminth eggs are among these agents, and their hardness and resistance to adverse environmental conditions allows them to survive in soils for months. With this in mind, we have launched a study of the presence of helminth eggs in the sludge of a wastewater treatment plant in Alboraia (Valencia). The results show a concentration of helminth eggs in digestion sludge of 27.000 eggs/kg dry matter. We discuss the potential sanitary relevant of these results and the need to continue with this evaluation program. (Author) 20 refs.

  16. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wijetunga, Somasiri, E-mail: swije2001@yahoo.com [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Li Xiufen [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Jian Chen, E-mail: jchen@sytu.edu.cn [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China)

    2010-05-15

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels ({approx}1000 mg/L, {approx}2000 mg/L, {approx}3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  17. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    International Nuclear Information System (INIS)

    Wijetunga, Somasiri; Li Xiufen; Jian Chen

    2010-01-01

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels (∼1000 mg/L, ∼2000 mg/L, ∼3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  18. [Using Excess Activated Sludge Treated 4-Chlorophenol Contained Waste Water to Cultivate Chlorella vulgaris].

    Science.gov (United States)

    Wang, Lu; Chen, Xiu-rong; Yan, Long; He, Yi-xuan; Shi, Zhen-dong

    2015-04-01

    Using different rations of sludge extracts and supernate from 4-Chlorophenol (4-CP) simulated wastewater's excess sludge after centrifugation to cultivate the Chlorella vulgaris to achieve the goal of excess sludge utilization together with chlorella cultivating. The experiments were performed in 500 mL flasks with different rations of sludge extracts & BG-11 and supernate & BG-11 in a light growth chamber respectively. Number of algal cells, Chlorophyll, enzyme activity, oil and water total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), toxicity index were investigated. Result showed that the nutrition supplies and toxicity in the excess sludge were removed efficiently via Chlorella vulgaris, the removal rates of TN and TP were at least 40% and 90% respectively; After 10 days cultivation, the density growth of 50% sludge extracts was 20 times higher of the beginning while its chlorophyll content was lower than that of the blank group. Sludge extracts could promote the proliferation of algae, but were not conducive to the synthesis of chlorophyll. The quantity of SOD in per cell showed Chlorella vulgaris gave a positive response via stimulation from toxicant in sludge extracts and supernate. The best time for collecting chlorella vulgaris was the fifth day of cultivation, taking neutral oil accumulation as the evaluating indicator for its utilization combined with the removal of supplies and toxicity.

  19. Sewage sludge and wastewater for use in agriculture. Proceedings of consultants meetings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    Recently, gamma rays and electron beams have been successfully used on sludges and wastewater to eliminate pathogenic organisms and some toxic chemicals. Sufficient technical data are available for gamma treatment of sludges, permitting its application on the demonstration or commercial scale, but gaps in our knowledge exist for the practical application of electron-beam technology. The IAEA`s involvement in studies of radiation processing of sewage sludge dates back several years. A five-year Co-ordinated Research programme on Radiation Treatment of Sewage Sludge for Safe Reutilization, involving Canada, Germany, India, Indonesia, Italy, Japan, and the United State of America, was completed in 1990. This programme laid a solid foundation on which future programmes can be built. However, at present, information is limited on the availability of nutrients from sewage sludges to crops, its benefits as an organic amendment to soil, and the harmful effects of heavy metals on crop growth. Isotope and radiation techniques are valuable tools of potential use in finding answers to some of these questions. Refs, figs, tabs.

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

    Science.gov (United States)

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

    2007-06-01

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

  1. Sewage sludge and wastewater for use in agriculture. Proceedings of consultants meetings

    International Nuclear Information System (INIS)

    1997-10-01

    Recently, gamma rays and electron beams have been successfully used on sludges and wastewater to eliminate pathogenic organisms and some toxic chemicals. Sufficient technical data are available for gamma treatment of sludges, permitting its application on the demonstration or commercial scale, but gaps in our knowledge exist for the practical application of electron-beam technology. The IAEA's involvement in studies of radiation processing of sewage sludge dates back several years. A five-year Co-ordinated Research programme on Radiation Treatment of Sewage Sludge for Safe Reutilization, involving Canada, Germany, India, Indonesia, Italy, Japan, and the United State of America, was completed in 1990. This programme laid a solid foundation on which future programmes can be built. However, at present, information is limited on the availability of nutrients from sewage sludges to crops, its benefits as an organic amendment to soil, and the harmful effects of heavy metals on crop growth. Isotope and radiation techniques are valuable tools of potential use in finding answers to some of these questions

  2. Protists as bioindicators in activated sludge: Identification, ecology and future needs.

    Science.gov (United States)

    Foissner, Wilhelm

    2016-08-01

    When the activated sludge process was developed, operators and scientists soon recognized protists as valuable indicators. However, only when Curds et al. (1968) showed with a few photographs the need of ciliates for a clear plant effluent, sewage protistology began to bloom but was limited by the need of species identification. Still, this is a major problem although several good guides are available. Thus, molecular kits should be developed for identification. Protists are indicators in two stages of wastewater treatment, viz., in the activated sludge and in the environmental water receiving the plant effluent. Continuous control of the protist and bacterial communities can prevent biological sludge foaming and bulking and may greatly save money for sludge oxygenation because several protist species are excellent indicators for the amount of oxygen present. The investigation of the effluent-receiving rivers gives a solid indication about the long term function of sewage works. The literature on protist bioindication in activated sludge is widely distributed. Thus, I compiled the data in a simple Table, showing which communities and species indicate good, mediocre, or poor plant performance. Further, many details on indication are provided, such as sludge loading and nitrifying conditions. Such specific features should be improved by appropriate statistics and more reliable identification of species. Then, protistologists have a fair chance to become important in wastewater works. Activated sludge is a unique habitat for particular species, often poorly or even undescribed. As an example, I present two new species. The first is a minute (∼30μm) Metacystis that makes an up to 300μm-sized mucous envelope mimicking a sludge floc. The second is a Phialina that is unique in having the contractile vacuole slightly posterior to mid-body. Finally, I provide a list of species which have the type locality in sewage plants. Copyright © 2016 Elsevier GmbH. All rights

  3. Isolation and Characterization of PHA-Producing Bacteria from Propylene Oxide Saponification Wastewater Residual Sludge.

    Science.gov (United States)

    Li, Ruirui; Gu, Pengfei; Fan, Xiangyu; Shen, Junyu; Wu, Yulian; Huang, Lixuan; Li, Qiang

    2018-03-21

    A polyhydroxyalkanoate (PHA)-producing strain was isolated from propylene oxide (PO) saponification wastewater activated sludge and was identified as Brevundimonas vesicularis UJN1 through 16S rDNA sequencing and Biolog microbiological identification. Single-factor and response surface methodology experiments were used to optimize the culture medium and conditions. The optimal C/N ratio was 100/1.04, and the optimal carbon and nitrogen sources were sucrose (10 g/L) and NH 4 Cl (0.104 g/L) respectively. The optimal culture conditions consisted of initial pH of 6.7 and an incubation temperature of 33.4 °C for 48 h, with 15% inoculum and 100 mL medium at an agitation rate of 180 rpm. The PHA concentration reached 34.1% of the cell dry weight and increased three times compared with that before optimization. The only report of PHA-producing bacteria by Brevundimonas vesicularis showed that the conversion rate of PHAs using glucose as the optimal carbon source was 1.67%. In our research, the conversion rate of PHAs with sucrose as the optimal carbon source was 3.05%, and PHA production using sucrose as the carbon source was much cheaper than that using glucose as the carbon source.

  4. Pyrolysis and oxy-fuel combustion characteristics and kinetics of petrochemical wastewater sludge using thermogravimetric analysis.

    Science.gov (United States)

    Chen, Jianbiao; Mu, Lin; Cai, Jingcheng; Yao, Pikai; Song, Xigeng; Yin, Hongchao; Li, Aimin

    2015-12-01

    The pyrolysis and oxy-fuel combustion characteristics of petrochemical wastewater sludge (PS) were studied in air (O2/N2) and oxy-fuel (O2/CO2) atmospheres using non-isothermal thermogravimetric analysis (TGA). Pyrolysis experiments showed that the weight loss profiles were almost similar up to 1050K in both N2 and CO2 atmospheres, while further weight loss took place in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Compared with 20%O2/80%N2, the drying and devolatilization stage of PS were delayed in 20%O2/80%CO2 due to the differences in properties of the diluting gases. In oxy-fuel combustion experiments, with O2 concentration increasing, characteristic temperatures decreased, while characteristic combustion rates and combustion performance indexes increased. Kinetic analysis of PS decomposition under various atmospheres was performed using Coats-Redfern approach. The results indicated that, with O2 concentration increasing, the activation energies of Step 1 almost kept constant, while the values of subsequent three steps increased. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Deng, Dongyang; Lin, Lian-Shin

    2017-05-01

    This study evaluated the technical feasibility of packed-bed sulfidogenic bioreactors dosed with ferrous chloride for continuous wastewater treatment over a 450-day period. In phase I, the bioreactors were operated under different combinations of carbon, iron, and sulfate mass loads without sludge recycling to identify optimal treatment conditions. A COD/sulfate mass ratio of 2 and a Fe/S molar ratio of 1 yielded the best treatment performance with COD oxidation rate of 786 ± 82 mg/(L⋅d), which resulted in 84 ± 9% COD removal, 94 ± 6% sulfate reduction, and good iron retention (99 ± 1%) under favorable pH conditions (6.2-7.0). In phase II, the bioreactors were operated under this chemical load combination over a 62-day period, during which 7 events of sludge collection, oxidation, and recycling were performed. The collected sludge materials contained both inorganic and organic matter with FeS and 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.

  6. Successful bioaugmentation of an activated sludge reactor with Rhodococcus sp. YYL for efficient tetrahydrofuran degradation

    International Nuclear Information System (INIS)

    Yao, Yanlai; Lu, Zhenmei; Zhu, Fengxiang; Min, Hang; Bian, Caimiao

    2013-01-01

    Highlights: • Rhodococcus sp. YYL is an efficient tetrahydrofuran-degrading strain. • Strain YYL was used to augment an activated sludge system for THF degradation. • Successful bioaugmentation was achieved only by coinoculation of strain YYL and the two bacilli. • Successful bioaugmentation of the system resulted in efficient THF degradation. -- Abstract: The exchange of tetrahydrofuran (THF)-containing wastewater should significantly affect the performance of an activated sludge system. In this study, the feasibility of using THF-degrading Rhodococcus sp. strain YYL to bioaugment an activated sludge system treating THF wastewater was explored. As indicated by a DGGE analysis, strain YYL alone could not dominate the system, with the concentration of mixed liquor suspended solids (MLSS) decreasing to nearly half of the initial concentration after 45 d, and the microbial diversity was found to be significantly reduced. However, after the reactor was augmented with the mixed culture of strain YYL and two bacilli initially coexisting in the enriched isolation source, strain YYL quickly became dominant in the system and was incorporated into the activated sludge. The concentration of MLSS increased from 2.1 g/L to 7.3 g/L in 20 d, and the efficiency of THF removal from the system was remarkably improved. After the successful bioaugmentation, more than 95% of THF was completely removed from the wastewater when 20 mM THF was continuously loaded into the system. In conclusion, our research first demonstrates that bioaugmentation of activated sludge system for THF degradation is feasible but that successful bioaugmentation should utilize a THF-degrading mixed culture as the inoculum, in which the two bacilli might help strain YYL colonize in activated sludge by co-aggregation

  7. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.

    2003-01-01

    of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...

  8. Respirometry techniques and activated sludge models

    NARCIS (Netherlands)

    Benes, O.; Spanjers, H.; Holba, M.

    2002-01-01

    This paper aims to explain results of respirometry experiments using Activated Sludge Model No. 1. In cases of insufficient fit of ASM No. 1, further modifications to the model were carried out and the so-called "Enzymatic model" was developed. The best-fit method was used to determine the effect of

  9. Co-composting of hair waste from the tanning industry with de-inking and municipal wastewater sludges.

    Science.gov (United States)

    Barrena, Raquel; Pagans, Estel la; Artola, Adriana; Vázquez, Felícitas; Sánchez, Antoni

    2007-06-01

    Production of waste hair in the leather manufacturing industry is increasing every year due to the adoption of hair-save unhairing techniques, leaving the tanners with the problem of coping with yet another solid by-product. Numerous potential strategies for hair utilisation have been proposed. However, the use of hair waste as agricultural fertiliser is one of its most promising applications due to the high nitrogen content of hair. Agricultural value of hair can be increased by composting. This paper deals with the composting of hair from the unhairing of bovine hide. Results indicated that hair cannot be either composted on its own or co-composted with de-inking sludge, a chemical complementary co-substrate. However, good results were obtained when co-composted with raw sludge from a municipal wastewater treatment plant at hair:raw sludge weight ratios 1:1, 1:2 and, 1:4 in lab scale and pilot plant scale composters. In all cases, a more stable product was achieved at the end of the process. Composting in the pilot plant composter was effectively monitored using Static Respiration Indices determined at process temperature at sampling (SRI(T)) and at 37 degrees C (SRI(37)). Notably, SRI(T) values were more sensitive to changes in the biological activity. In contrast, Respiratory Quotient (RQ) values were not adequate to follow the development of the process.

  10. Analysis of Pharmaceutical and Personal Care Compounds in Wastewater Sludge and Aqueous Samples using GC-MS/MS

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Lirong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mitroshkov, Alexandre V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gilmore, Tyler J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-15

    The Bioenergy Program at Pacific Northwest National Laboratory (PNNL) is evaluating the feasibility of converting wastewater sludge materials to fuels. Wastewater sludge from various municipalities will be used in the evaluation process and as with any municipal waste, there is the potential for residual contaminates to remain in the sludge following wastewater treatment. Many surveys and studies have confirmed the presence of pharmaceuticals in municipal wastewater and effluents (World Health Organization, 2011). Determination of the presence and concentrations of the contaminants is required to define the proper handling of this sludge. A list of targeted compounds was acquired from the literature and an analytical method was developed for the pharmaceutical and personal care compounds. The presence of organics complicated the analytical techniques and, in some cases, the precision of the results. However, residual concentrations of a range of compounds were detected in the wastewater sludge and the presence and concentrations of these compounds will be considered in identifying the appropriate handling of this material in conduct of research.

  11. Co-production of hydrogen and methane from herbal medicine wastewater by a combined UASB system with immobilized sludge (H2 production) and UASB system with suspended sludge (CH4 production).

    Science.gov (United States)

    Sun, Caiyu; Hao, Ping; Qin, Bida; Wang, Bing; Di, Xueying; Li, Yongfeng

    2016-01-01

    An upflow anaerobic sludge bed (UASB) system with sludge immobilized on granular activated carbon was developed for fermentative hydrogen production continuously from herbal medicine wastewater at various organic loading rates (8-40 g chemical oxygen demand (COD) L(-1) d(-1)). The maximum hydrogen production rate reached 10.0 (±0.17) mmol L(-1) hr(-1) at organic loading rate of 24 g COD L(-1) d(-1), which was 19.9% higher than that of suspended sludge system. The effluents of hydrogen fermentation were used for continuous methane production in the subsequent UASB system. At hydraulic retention time of 15 h, the maximum methane production rate of 5.49 (±0.03) mmol L(-1) hr(-1) was obtained. The total energy recovery rate by co-production of hydrogen and methane was evaluated to be 7.26 kJ L(-1) hr(-1).

  12. Ultrasound assisted biogas production from co-digestion of wastewater sludges and agricultural wastes: Comparison with microwave pre-treatment.

    Science.gov (United States)

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

    2018-01-01

    This study investigates the effect of ultrasonication and microwave sludge disintegration/pre-treatment techniques on the anaerobic co-digestion efficiency of wastewater sludges with olive and grape pomaces. The effects of both co-digestion and sludge pre-treatment techniques were evaluated in terms of the organic removal efficiency and the biogas production. The "co-digestion" of wastewater sludge with both types of pomaces was revealed to be a much more efficient way for the biogas production compared to the single (mono) sludge digestion. The ultrasonication and microwave pre-treatments applied to the sludge samples caused to a further increase in biogas and methane yields. Based on applied specific energies, ultrasonication pre-treatment was found much more effective than microwave irradiation. The specific energy applied in microwave pre-treatment (87,000kj/kgTS) was almost 9 times higher than that of used in ultrasonication (10,000kj/kgTS), resulting only 10-15% increases in biogas/methane yield. Co-digestion of winery and olive industry residues with pre-treated wastewater sludges appears to be a suitable technique for waste management and energy production. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. MiDAS Field Guide – a Comprehensive Online Source of Information About the Microbes of Activated Sludge

    DEFF Research Database (Denmark)

    Nierychlo, Marta; McIlroy, Simon Jon; Saunders, Aaron Marc

    activated sludge wastewater treatment systems, linking their identity with available information on their function and distribution. The guide includes the approx. 100 abundant genera that are present in most treatment plants (based on a survey of 25 full-scale Danish wastewater treatment plants...... are provided. The MiDAS Field Guide is a continuously developing resource where all working in the field are invited to contribute....... that would be otherwise excluded from analyses. The MiDAS database importantly provides a common taxonomy for the field that gives a solid foundation for the study of microbial ecology of the activated sludge process and related wastewater treatment processes, such as biofilms and granular sludge. Each genus...

  14. Dosage of high COD industrial wastewaters as an external carbon source in the pre-denitrification step of activated sludge plants; Utilizzo di reflui industriali a elevato COD come fonte esterna di carbonio in pre-denitrificazione negli impianti a fanghi attivi

    Energy Technology Data Exchange (ETDEWEB)

    Bertanza, G.; Collivignarelli, C.; Pedrazzani, R. [Brescia Univ., Brescia (Italy). Facolta' di Ingegneria, Dipt. di Ingegneria Civile

    2001-04-01

    In pre-denitrification plants, the organic carbon shortage in the influent wastewater can inhibit the denitrification process. In this case, the dosage of organic substrates can be considered, when the F/M ratio in the nitrification stage is adequate. Beside commonly available substances (acetic acid, methanol etc.) industrial wastewaters can be dosed. This research was aimed to assess the feasibility of this alternative, by testing several industrial wastewaters in addition to real municipal wastewater. The experiment consisted in running a continuous-flow activated sludge pilot plant and in carrying out NUR (Nitrogen Uptake Rate) tests. The studied wastewaters derive from the food industry and, more precisely, from cocoa working and from the cold drink industry. Results were compared with two reference situations (dosage of sodium acetate and of an available organic solution). [Italian] Negli impianti con pre-denitrificazione, il processo di denitrificazione puo' essere inibito dalla carenza di carbonio organico nel liquame influente. Un rimedio (applicabile qualora il carico del fango in nitrificazione sia compatibile) consiste nel dosaggio di substrati carboniosi. Accanto alle soluzioni commercializzate (acido acetico, metanolo, ecc.) e' possibile dosare reflui industriali aventi caratteristiche adeguate. Nel presente studio si e' voluta verificare tale alternativa mediante una sperimentazione svolta su liquame fognario a cui sono stati aggiunti, di volta in volta, diversi substrati carboniosi. Le prove sono state effettuate sia in continuo (mediante l'impiego di un impianto pilota a fanghi attivi) sia in batch (test di NUR - Nitrogen Uptake Rate). I reflui studiati originano dall'industria alimentare, in particolare, dalla laovrazione del cacao e dalla produzione di bevande analcoliche. I risultati sono stati confrontati con due situazioni di riferimento (dosaggio di acetato di sodio e di una soluzione carboniosa disponibile in

  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.

    2009-07-01

    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. Earthworm-microorganism interactions: a strategy to stabilize domestic wastewater sludge.

    Science.gov (United States)

    Zhao, Limin; Wang, Yayi; Yang, Jian; Xing, Meiyan; Li, Xiaowei; Yi, Danghao; Deng, Dehan

    2010-04-01

    The performance of a conventional biofilter (BF) and a vermifilter containing the earthworm, Eisenia foetida, (VF) for the treatment of domestic wastewater sludge were compared with the earthworm-microorganism interaction mechanisms involved in sludge stabilization. The results revealed that the presence of earthworms in the VF led to significant stabilization of the sludge by enhancing the reduction in volatile suspended solids (VSS) by 25.1%. Digestion by earthworms and the earthworm-microorganism interactions were responsible for 54% and 46% of this increase, respectively. Specifically, earthworms in the VF were capable of transforming insoluble organic materials to a soluble form and then selectively digesting the sludge particles of 10-200 microm to finer particles of 0-2 microm, which led to the further degradation of organic materials by the microorganisms in the reactor. Additionally, denaturing gradient gel electrophoresis (DGGE) profiles showed that there was an intensified bacterial diversity in the vermifilter due to the presence of earthworms, especially in response to the nutrients in their casts. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Ren, Yuan; Yang, Juan; Chen, Shaoyi

    2015-12-01

    This paper describes the fate of a nitrobenzene-degrading bacterium, Klebsiella oxytoca NBA-1, which was isolated from a pharmaceutical wastewater treatment facility. The 90-day survivability of strain NBA-1 after exposure to sludge under anaerobic and aerobic conditions was investigated. The bacterium was inoculated into sludge amended with glucose and p-chloronitrobenzene (p-CNB) to compare the bacterial community variations between the modified sludge and nitrobenzene amendment. The results showed that glucose had no obvious effect on nitrobenzene biodegradation in the co-metabolism process, regardless of the presence/absence of oxygen. When p-CNB was added under anaerobic conditions, the biodegradation rate of nitrobenzene remained unchanged although p-CNB inhibited the production of aniline. The diversity of the microbial community increased and NBA-1 continued to be one of the dominant strains. Under aerobic conditions, the degradation rate of both nitrobenzene and p-CNB was only 20% of that under anaerobic conditions. p-CNB had a toxic effect on the microorganisms in the sludge so that most of the DGGE (denaturing gradient gel electrophoresis) bands, including that of NBA-1, began to disappear under aerobic conditions after 90days of exposure. These data show that the bacterial community was stable under anaerobic conditions and the microorganisms, including NBA-1, were more resistant to the adverse environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Carbamazepine behaviour and effects in an urban wastewater MBR working with high sludge and hydraulic retention time.

    Science.gov (United States)

    González-Pérez, Daniel María; Pérez, Jorge Ignacio; Nieto, Miguel Ángel Gómez

    2016-08-23

    The behaviour and fate of carbamazepine (CBZ) in urban wastewater treatment by a membrane bioreactor (MBR) and its possible effects on the system's efficiency, and on mixed microbial communities, has been studied. The experimental microfiltration MBR system, with capacity to treat 10.8 m(3) d(-1) of urban wastewater, operated with a pre-denitrification configuration with high sludge and hydraulic retention time. The CBZ concentration assayed was higher than in the usual urban wastewater, in order to provoke a strong biomass reaction. Influent, effluent, and all bioreactors of the MBR system were analysed in order to calculate a CBZ balance. Bench-scale experiments and respirometric analyses were performed, with and without the presence of CBZ, to evaluate its influence on the bacterial activity. The respirometric assays showed variations in the oxygen uptake rate (OUR) in the presence of CBZ. Negative effects were detected in the MBR bacterial community during the initial period of dosing. However, the effects were not permanent and the biomass spiked with CBZ had behaviour similar to that of the biomass without CBZ after a few hours. Biodegradation was not detected during the MBR treatment. The system showed an inefficient elimination of CBZ (less than 10%) with a high concentration in the effluent. The small percentage of CBZ removal was associated with the sludge retention and eliminated by the purge. All CBZ present in the influent was accounted for, and even an increase in the total amount of CBZ was registered in the permeate. During and after the experimental process, CBZ did not significantly affect the efficiency of the MBR system, and the quality of the effluent was not affected by the dosing of CBZ in terms of COD and nitrogen removal.

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

    Science.gov (United States)

    Zhang, Yuyao; Li, Huan

    2017-09-18

    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. Electrodialytic treatment of municipal wastewater and sludge for the removal of heavy metals and recovery of phosphorus

    DEFF Research Database (Denmark)

    Ebbers, Benjamin; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2015-01-01

    Municipal wastewater and sewage sludge is an abundant source of phosphorus (P), but its usage is often limited due to wastewater treatment methods and contaminants, mostly heavy metals (HM's). Three compartment (3C) electrodialysis (ED) was used to simultaneously extract HM's (Cd, Cr, Cu, Ni, Pb...... of heavy metals or recovery of phosphorus using ED, the end-products in wastewater treatment, like anaerobically digested sludge and reject-water streams, are therefore best to be treated....... pH using anaerobically digested sludge. The hydrolysis of OM during anaerobic digestion and the anaerobic conditions allowed for easier extraction of HM's such as Cd, Ni and Zn as they had fewer adsorption places, and improved P availability and extractability. Extraction of P from high...

  1. Effects of ultrasonic disintegration on sludge microbial activity and dewaterability

    International Nuclear Information System (INIS)

    Li Huan; Jin Yiying; Mahar, Rasool Bux; Wang Zhiyu; Nie Yongfeng

    2009-01-01

    Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl 3 . It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration

  2. Effects of ultrasonic disintegration on sludge microbial activity and dewaterability.

    Science.gov (United States)

    Huan, Li; Yiying, Jin; Mahar, Rasool Bux; Zhiyu, Wang; Yongfeng, Nie

    2009-01-30

    Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl(3). It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration.

  3. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liang, E-mail: felix79cn@hotmail.com [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China); Jin, Jie [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Lin, Haizhuan [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Wenzhou Environmental Protection Design Scientific Institute, Wenzhou 325000 (China); Gao, Kaituo [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Xu, Xiangyang, E-mail: xuxy@zju.edu.cn [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China)

    2015-03-21

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m{sup −3} d{sup −1} and 6.0–70.0 g m{sup −3} d{sup −1}, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H{sub 2}/CH{sub 4} production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion.

  4. Enhanced micropollutant biodegradation and assessment of nitrous oxide concentration reduction in wastewater treated by acclimatized sludge bioaugmentation.

    Science.gov (United States)

    Boonnorat, Jarungwit; Techkarnjanaruk, Somkiet; Honda, Ryo; Ghimire, Anish; Angthong, Sivakorn; Rojviroon, Thammasak; Phanwilai, Supaporn

    2018-05-11

    This research investigated the micropollutant biodegradation and nitrous oxide (N 2 O) concentration reduction in high strength wastewater treated by two-stage activated sludge (AS) systems with (bioaugmented) and without (non-bioaugmented) acclimatized sludge bioaugmentation. The bioaugmented and non-bioaugmented systems were operated in parallel for 228 days, with three levels of concentrations of organics, nitrogen, and micropollutants in the influent: conditions 1 (low), 2 (moderate), and 3 (high). The results showed that, under condition 1, both systems efficiently removed the organic and nitrogen compounds. However, the bioaugmented system was more effective in the micropollutant biodegradation and N 2 O concentration reduction than the non-bioaugmented one. Under condition 2, the nitrogen and micropollutant biodegradation efficiency of the non-bioaugmented system slightly decreased, while the N 2 O concentration declined in the bioaugmented system. Under condition 3, the treatment performance and N 2 O concentration abatement were substantially lowered as the compounds concentration increased. Further analysis also showed that the acclimatized sludge bioaugmentation increased the bacterial diversity in the system. In essence, the acclimatized sludge bioaugmentation strategy was highly effective for the influent with low compounds concentration, achieving the organics and nitrogen removal efficiencies of 92-97%, relative to 71-97% of the non-bioaugmented system. The micropollutant treatment efficiency of the bioaugmented system under condition 1 was 75-92%, indicating significant improvement in the treatment performance (p < 0.05), compared with 60-79% of the non-bioaugmented system. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    International Nuclear Information System (INIS)

    Zhu, Liang; Jin, Jie; Lin, Haizhuan; Gao, Kaituo; Xu, Xiangyang

    2015-01-01

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m −3 d −1 and 6.0–70.0 g m −3 d −1 , and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H 2 /CH 4 production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion

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

    Science.gov (United States)

    Nair, Abhilash T; Ahammed, M Mansoor

    2014-09-01

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

  7. Effects of mechanical disintegration of activated sludge on the activity of nitrifying and denitrifying bacteria and phosphorus accumulating organisms.

    Science.gov (United States)

    Zubrowska-Sudol, Monika; Walczak, Justyna

    2014-09-15

    The purpose of the study was to analyse the impact of hydrodynamic disintegration of thickened excess activated sludge, performed at different levels of energy density (70, 140 and 210 kJ/L), on the activity of microorganisms involved in nutrient removal from wastewater, i.e. nitrifiers, denitrifiers and phosphorus accumulating organisms (PAOs). Ammonium and nitrogen utilisation rates and phosphorus release rates for raw and disintegrated sludge were determined using batch tests. The experiment also included: 1) analysis of organic and nutrient compound release from activated sludge flocs, 2) determination of the sludge disintegration degree (DD), and 3) evaluation of respiratory activity of the biomass by using the oxygen uptake rate (OUR) batch test. It was shown that the activity degree of the examined groups of microorganisms depended on energy density and related sludge disintegration degree, and that inactivation of individual groups of microorganisms occurred at different values of DD. Least resistant to the destruction of activated sludge flocs turned out to be phosphorus accumulating organisms, while the most resistant were denitrifiers. A decrease of 20-40% in PAO activity was noted already at DD equal to 3-5%. The threshold values of DD, after crossing which the inactivation of nitrifiers and denitrifiers occurred, were equal to 8% and 10%, respectively. At lesser DD values an increase in the activity of these groups of microorganisms was observed, averaging 20.2-41.7% for nitrifiers and 9.98-36.3% for denitrifiers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Occurrence, identification and removal of microplastic particles and fibers in conventional activated sludge process and advanced MBR technology.

    Science.gov (United States)

    Lares, Mirka; Ncibi, Mohamed Chaker; Sillanpää, Markus; Sillanpää, Mika

    2018-04-15

    Wastewater treatment plants (WWTPs) are acting as routes of microplastics (MPs) to the environment, hence the urgent need to examine MPs in wastewaters and different types of sludge through sampling campaigns covering extended periods of time. In this study, the efficiency of a municipal WWTP to remove MPs from wastewater was studied by collecting wastewater and sludge samples once in every two weeks during a 3-month sampling campaign. The WWTP was operated based on the conventional activated sludge (CAS) process and a pilot-scale membrane bioreactor (MBR). The microplastic particles and fibers from both water and sludge samples were identified by using an optical microscope, Fourier Transform Infrared (FTIR) microscope and Raman microscope. Overall, the retention capacity of microplastics in the studied WWTP was found to be 98.3%. Most of the MP fraction was removed before the activated sludge process. The efficiency of an advanced membrane bioreactor (MBR) technology was also examined. The main related finding is that MBR permeate contained 0.4 MP/L in comparison with the final effluent of the CAS process (1.0 MP/L). According to this study, both microplastic fibers and particles are discharged from the WWTP to the aquatic environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. AB activated sludge process for a wastewater treatment with a high industrial contribution; Proceso de fangos activos de doble etapa para tratamiento de aguas residuales con fuerte componente industrial

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigo, J. C.; Jorda, J. R.; Gonzalez, A. I.

    2003-07-01

    In a WWTP with a high industrial contribution is essential to choose a proper process as well as a correct lay out of the plant in order to get an efficient treatment. In this article, results from a AB activated sludge process set in Bejar (Salamanca) WWTP are shown. In the same way, it is exposed a diagnosis report made from the waste water carried out on a pilot plant which allowed to verify and improve the biological design and final lay out of the plant. Finally, advantages and disadvantages are evaluated as result of the work implemented. (Author) 5 refs.

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

    Science.gov (United States)

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

    2014-06-01

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

  11. A comparison of BNR activated sludge systems with membrane and settling tank solid-liquid separation.

    Science.gov (United States)

    Ramphao, M C; Wentzel, M C; Ekama, G A; Alexander, W V

    2006-01-01

    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only to the design of the membrane bio-reactor (MBR) BNR system itself, but also to the design approach for the whole wastewater treatment plant (WWTP). In multi-zone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic and aerobic zones (i.e. fixed volume fractions), the mass fractions can be controlled (within a range) with the inter-reactor recycle ratios. This zone mass fraction flexibility is a significant advantage of MBR BNR systems over BNR systems with secondary settling tanks (SSTs), because it allows changing the mass fractions to optimise biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios (fq) in the upper range (fq approximately 2.0), aerobic mass fractions in the lower range (f(maer) settling and long sludge age). However, the volume reduction compared with equivalent BNR systems with SSTs will not be large (40-60%), but the cost of the membranes can be offset against sludge thickening and stabilisation costs. Moving from a flow unbalanced raw wastewater system to a flow balanced (fq = 1) low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes away from extended aeration to include primary sludge stabilisation. The cost of primary sludge treatment then has to be offset against the savings of the increased WWTP capacity.

  12. Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

    Directory of Open Access Journals (Sweden)

    Abumalé Cruz-Salomón

    2017-12-01

    Full Text Available Untreated agro-industrial wastewaters are undesirable in the aquatic environment due to the presence of high organic matter contents. However, they may constitute a large potential for biogas production. The present investigation is focused on three laboratory-scale anaerobic expanded granular sludge bed (EGSB bioreactors, continuously operated for 60 d under mesophilic condition with the aim of exploring the feasibility of treating three most significant agro-industrial wastewaters in Chiapas, Mexico (i.e., cheese whey, vinasse, and coffee-processing wastewater. The EGSB bioreactors were operated with a hydraulic retention time (HRT of 6 d under stable conditions (i.e., buffer index (BI of 0.31, 0.34, and 0.03, generating a maximum chemical oxygen demand (COD removal efficiency of 91, 74, and 96% with an average methane production of 340, 245, and 300 mL/g COD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively. According to the obtained results, the EGSB bioreactors could be a sustainable alternative to simultaneously solve the environmental problems and to produce bioenergy.

  13. The effects of modification for contact stabilization activated sludge on EBPR

    Directory of Open Access Journals (Sweden)

    Hamdy I. Ali

    2015-04-01

    Available design and research information for the EBPR process were directly related to organic strength, solids and phosphorus content in wastewater. The success of excess biological phosphorus removal (EBPR process is largely dependent on the characteristics of organic carbon present in wastewater. The COD and BOD5 content of wastewater will also determine whether a phosphorus removal EBPR system is required. For this paper, the performance of EBPR was investigated using modified contact stabilization activated sludge pilot plant. The study involved the construction of pilot plant which was setup in Quhafa WasteWater Treatment Plant (WWTP, Al Fayoum, Egypt. Results showed average removal efficiencies of COD, BOD5 and TP are 91%, 92% and 85% respectively.

  14. 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)

    2016-06-08

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

  15. Activated sludge models ASM1, ASM2, ASM2d and ASM3

    DEFF Research Database (Denmark)

    Henze, Mogens; Gujer, W.; Mino, T.

    This book has been produced to give a total overview of the Activated Sludge Model (ASM) family at the start of 2000 and to give the reader easy access to the different models in their original versions. It thus presents ASM1, ASM2, ASM2d and ASM3 together for the first time.Modelling of activated...... sludge processes has become a common part of the design and operation of wastewater treatment plants. Today models are being used in design, control, teaching and research.ContentsASM3: Introduction, Comparison of ASM1 and ASM3, ASM3: Definition of compounds in the model, ASM3: Definition of processes...... in the Model, ASM3: Stoichiometry, ASM3: Kinetics, Limitations of ASM3, Aspects of application of ASM3, ASM3C: A Carbon based model, Conclusion ASM 2d: Introduction, Conceptual Approach, ASM 2d, Typical Wastewater Characteristics and Kinetic and Stoichiometric Constants, Limitations, Conclusion ASM 2...

  16. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-07-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD{sub i}nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  17. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    International Nuclear Information System (INIS)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-01-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD i nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

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

    Science.gov (United States)

    Fragoso, R A; Duarte, E A

    2012-01-01

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

  19. Rapid determination of filamentous microorganisms in activated sludge; Determinacion rapida de microorganismos filamentosos en fangos activados

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Jimenez, C.; Estevez, F. [Empresa Municipal de Abastecimiento y Saneamiento de Aguas de Sevilla (Spain)

    1999-07-01

    Despite many methods available biomass estimation of a bioprocess may sometimes become laborious and impracticable. Samples containing filamentous organisms, as in Wastewater Treatment Plants, present special counting difficulties. If they are abundant they may need to be estimated separately. In this work a counting method for these organisms is show. The main goal is to improve chlorination of activated sludge suffering bulking or foaming through a quantitative record of filamentous bacteria. (Author) 12 refs.

  20. Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

    International Nuclear Information System (INIS)

    Yin, Yanan; Wang, Jianlong

    2015-01-01

    Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

  1. Gravity Drainage of Activated Sludge on Reed Beds

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian

    and operation of reed beds and the efficiencies are often lower than predicted. One reason is that the sludge quality varies from plant to plant and even within plants from time to time. No good method exists for measuring the sludge quality with respect to drainage characteristics. A new experimental method...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows......Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...

  2. Improved waste-activated sludge dewatering using sludge/oil ...

    African Journals Online (AJOL)

    2014-10-07

    Oct 7, 2014 ... 2Dept. of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seongdong-Gu, Seoul 133-791, ... conventional heating methods in chemical reactions is becom- ... the dewaterability of sludge and reduces the organic matter ..... It is unlikely that this technique will be applied in.

  3. Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

    Directory of Open Access Journals (Sweden)

    Luca Zuliani

    2016-10-01

    Full Text Available Microalgae are fast-growing photosynthetic organisms which have the potential to be exploited as an alternative source of liquid fuels to meet growing global energy demand. The cultivation of microalgae, however, still needs to be improved in order to reduce the cost of the biomass produced. Among the major costs encountered for algal cultivation are the costs for nutrients such as CO2, nitrogen and phosphorous. In this work, therefore, different microalgal strains were cultivated using as nutrient sources three different anaerobic digestates deriving from municipal wastewater, sewage sludge or agro-waste treatment plants. In particular, anaerobic digestates deriving from agro-waste or sewage sludge treatment induced a more than 300% increase in lipid production per volume in Chlorella vulgaris cultures grown in a closed photobioreactor, and a strong increase in carotenoid accumulation in different microalgae species. Conversely, a digestate originating from a pilot scale anaerobic upflow sludge blanket (UASB was used to increase biomass production when added to an artificial nutrient-supplemented medium. The results herein demonstrate the possibility of improving biomass accumulation or lipid production using different anaerobic digestates.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ongen, Atakan, E-mail: aongen@istanbul.edu.tr; Kurtulus Ozcan, H.; Arayıcı, Semiha

    2013-12-15

    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.

  6. Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-11-13

    Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

  7. Uses of biogas produced by digestion of wastewater sludge. The SIAAP's experience feedback and projects

    International Nuclear Information System (INIS)

    Amosse, S.; Nedelec, R.

    2010-01-01

    The SIAAP, in charge of the purification of the Great Paris wastewaters (8 M inhabitants), handles 2.7 Mm 3 /day. Five wastewater treatment plants permit to dean these wastewaters before they are discharged into the receiving environment: 'Seine Aval' (Acheres, 1,7 Mm 3 /day), 'Seine Amont' (Valenton, 600 000 m 3 /day), 'Seine Centre' (Colombes, 240 000 m 3 /day), 'Seine Gresillons' (Triel-sur-Seine, 100 000 m 3 /day) and 'Marne Aval' (Noisy-Le-Grand, 40 000 m 3 /day). Biogas produced by digestion of sludge provides a part of the energy required by the five sewage treatment works. Energy recovered from biogas have been used by the SAV site since 1940. As soon as the first part of this plant started up, biogas was used as fuel to heat digester, to produce power through biogas engines and to drive blowers. In the 60's and 70's, dual-fuel engines were brought into service, and then in 1992, a gas turbine was installed. Nowadays, a combined heat and power (cogeneration) project is in progress with the installation of two gas turbines, each generating 5 MW. All of these installations had allowed a 70% energetic autonomy ratio on 'Seine Aval' site. Then, new treatment units were introduced. Thus, energy consumption has increased, with only 60 % of energy demands being covered. By 2020, a complete make-over of the 'Seine Aval' plant will be done. This should allow to cover about 70% of energy demands, partly thanks to biogas reuse. New plants are currently being constructed. All of them will include sludge digestion process providing biogas. With the 'Seine Gresillons' plant upgrading, digestion process will occur on site. Biogas will be used in a cogeneration system to produce both electricity (that would be either used on site or sold commercially, this has not been decided by now) and heat for digesters heating. The new 'Seine Moree' plant will be built in the city of Blanc-Mesnil. A partnership with the Syctom (an association in charge of treatment and reuse of the

  8. Dairy wastewater treatment

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... treatment processes to treat dairy wastewater such as activated sludge system .... Gas chromatograph. (Perkin Elmer, Auto system XL), equipped with thermal conductivity ..... Enzymatic hydrolysis of molasses. Bioresour. Tech.

  9. Optimization and modeling of reduction of wastewater sludge water content and turbidity removal using magnetic iron oxide nanoparticles (MION).

    Science.gov (United States)

    Hwang, Jeong-Ha; Han, Dong-Woo

    2015-01-01

    Economic and rapid reduction of sludge water content in sewage wastewater is difficult and requires special advanced treatment technologies. This study focused on optimizing and modeling decreased sludge water content (Y1) and removing turbidity (Y2) with magnetic iron oxide nanoparticles (Fe3O4, MION) using a central composite design (CCD) and response surface methodology (RSM). CCD and RSM were applied to evaluate and optimize the interactive effects of mixing time (X1) and MION concentration (X2) on chemical flocculent performance. The results show that the optimum conditions were 14.1 min and 22.1 mg L(-1) for response Y1 and 16.8 min and 8.85 mg L(-1) for response Y2, respectively. The two responses were obtained experimentally under this optimal scheme and fit the model predictions well (R(2) = 97.2% for Y1 and R(2) = 96.9% for Y2). A 90.8% decrease in sludge water content and turbidity removal of 29.4% were demonstrated. These results confirm that the statistical models were reliable, and that the magnetic flocculation conditions for decreasing sludge water content and removing turbidity from sewage wastewater were appropriate. The results reveal that MION are efficient for rapid separation and are a suitable alterative to sediment sludge during the wastewater treatment process.

  10. MiDAS: the field guide to the microbes of activated sludge.

    Science.gov (United States)

    McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2015-01-01

    The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes--knowledge that will be an invaluable resource for the optimal design and operation of these systems. © The Author(s) 2015. Published by Oxford University Press.

  11. Aerobic composting of waste activated sludge: Kinetic analysis for microbiological reaction and oxygen consumption

    International Nuclear Information System (INIS)

    Yamada, Y.; Kawase, Y.

    2006-01-01

    In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan) using 4 and 20 L laboratory scale bioreactors. Aeration rate, compositions of compost mixture and height of compost pile were investigated as main design and operating parameters. The optimal aerobic composting of waste activated sludge was found at the aeration rate of 2.0 L/min/kg (initial composting mixture dry weight). A compost pile up to 0.5 m could be operated effectively. A simple model for composting of waste activated sludge in a composting reactor was developed by assuming that a solid phase of compost mixture is well mixed and the kinetics for microbiological reaction is represented by a Monod-type equation. The model predictions could fit the experimental data for decomposition of waste activated sludge with an average deviation of 2.14%. Oxygen consumption during composting was also examined using a simplified model in which the oxygen consumption was represented by a Monod-type equation and the axial distribution of oxygen concentration in the composting pile was described by a plug-flow model. The predictions could satisfactorily simulate the experiment results for the average maximum oxygen consumption rate during aerobic composting with an average deviation of 7.4%

  12. Chitosan use in chemical conditioning for dewatering municipal-activated sludge.

    Science.gov (United States)

    Zemmouri, H; Mameri, N; Lounici, H

    2015-01-01

    This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl₃). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl₃and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl₃allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10¹², 0.932 × 10¹² and 2 × 10¹² m/kg for Sed CF802, chitosan and FeCl₃respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl₃.

  13. Effect of Cambi Thermal Hydrolysis Process-Anaerobic digestion treatment on concentrations on phthalate plasticisers in wastewater sludge

    Science.gov (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...

  14. Energy production from distillery wastewater using single and double-phase upflow anaerobic sludge blanket (UASB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Muyodi, F J; Rubindamayugi, M S.T. [Univ. of Dar es Salaam, Applied Microbiology Unit (Tanzania, United Republic of)

    1998-12-31

    A Single-phase (SP) and Double-phase (DP) Upflow Anaerobic Sludge Blanket (UASB) reactors treating distillery wastewater were operated in parallel. The DP UASB reactor showed better performance than the SP UASB reactor in terms of maximum methane production rate, methane content and Chemical Oxygen Demand (COD) removal efficiency. (au) 20 refs.

  15. Energy production from distillery wastewater using single and double-phase upflow anaerobic sludge blanket (UASB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Muyodi, F.J.; Rubindamayugi, M.S.T. [Univ. of Dar es Salaam, Applied Microbiology Unit (Tanzania, United Republic of)

    1997-12-31

    A Single-phase (SP) and Double-phase (DP) Upflow Anaerobic Sludge Blanket (UASB) reactors treating distillery wastewater were operated in parallel. The DP UASB reactor showed better performance than the SP UASB reactor in terms of maximum methane production rate, methane content and Chemical Oxygen Demand (COD) removal efficiency. (au) 20 refs.

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

    Science.gov (United States)

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

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

  17. Electrical field: a historical review of its application and contributions in wastewater sludge dewatering.

    Science.gov (United States)

    Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

    2010-04-01

    Electric field-assisted dewatering, also called electro-dewatering, is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. Electro-dewatering is not a new idea, but the practical industrial applications have been limited to niche areas in soil mechanics, civil engineering, and the ceramics industry. Recently, it has received great attention, specially, in the fields of fine-particle sludge, gelatinous sludge, sewage sludge, pharmaceutical industries, food waste and bull kelp, which could not be successfully dewatered with conventional mechanical methods. This review focuses on the scientific and practical aspects of the application of an electrical field in laboratory/industrial dewatering, and discusses this in relation to conventional dewatering techniques. A comprehensive bibliography of research in the electro-dewatering of wastewater sludges is included. As the fine-particle suspensions possess a surface charge, usually negative, they are surrounded by a layer with a higher density of positive charges, the electric double layer. When an electric field is applied, the usually negative charged particles move towards the electrode of the opposite charge. The water, commonly with cations, is driven towards the negative electrode. Electro-dewatering thus involves the well-known phenomena of electrophoresis, electro-osmosis, and electromigration. Following a detailed outline of the role of the electric double layer and electrokinetic phenomena, an analysis of the components of applied voltage and their significance is presented from an electrochemical viewpoint. The aim of this elementary analysis is to provide a fundamental understanding of the different process variables and configurations in order to

  18. 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

    2014-12-01

    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.

  19. Removal of lead (II) from metal plating effluents using sludge based activated carbon as adsorbent.

    Science.gov (United States)

    Raju, P; Saseetharan, M K

    2010-01-01

    A novel adsorbent was prepared from waste sludge obtained from a sugar mill for removing heavy metals from industrial wastewater. The adsorption studies were carried out in batch and continuous modes for both sugar mill sludge based carbon and commercial carbon. In batch studies, experiments were conducted at ambient temperature to assess the influence of the parameters such as pH, adsorbent dose, contact time and equilibrium concentration. Adsorption data for the prepared carbon was found to satisfy both the Freundlich and Langmuir isotherms. Column studies were carried out to delineate the effect of varying depth of carbon at constant flow rate. The breakthrough curves were drawn to establish the mechanism. The result shows that the sludge based activated carbon can be used as an alternative for commercial carbon.

  20. 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.

    2006-01-01

    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

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

    Science.gov (United States)

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

    2006-01-01

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

  2. Aerobic sludge granulation for simultaneous anaerobic decolorization and aerobic aromatic amines mineralization for azo dye wastewater treatment.

    Science.gov (United States)

    Yan, Lawrence K Q; Fung, Ka Y; Ng, Ka M

    2018-06-01

    In this study, the capability of using aerobic granules to undergo simultaneous anaerobic decolorization and aerobic aromatic amines degradation was demonstrated for azo dye wastewater treatment. An integrated acclimation-granulation process was devised, with Mordant Orange 1 as the model pollutant. Performance tests were carried out in a batch column reactor to evaluate the effect of various operating parameters. The optimal condition was to use 1.0-1.7 mm (1.51 ± 0.33 mm) granules, 5 g/L biomass, and 4000 mg/L organics as nutrient; and supplement the wastewater with 1  mg/L dissolved oxygen. This led to a dye mineralization of 61 ± 2%, an anaerobic dye removal of 88 ± 1%, and an aerobic aromatic amines removal of 70 ± 3% within 48 h. This study showed that simultaneous anaerobic/aerobic process by aerobic granules could be a possible alternative to the conventional activated sludge process.

  3. Levels and distribution patterns of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China

    International Nuclear Information System (INIS)

    Zeng Lixi; Wang Thanh; Ruan Ting; Liu Qian; Wang Yawei; Jiang Guibin

    2012-01-01

    Short chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutant candidates in the Stockholm Convention and are receiving more and more attentions worldwide. In general, concentrations of contaminants in sewage sludge can give an important indication on their pollution levels at a local/regional basis. In this study, SCCPs were investigated in sewage sludge samples collected from 52 wastewater treatment plants in China. Concentrations of total SCCPs (ΣSCCPs) in sludge were in the range of 0.80–52.7 μg/g dry weight (dw), with a mean value of 10.7 μg/g dw. Most of SCCPs in the sludge samples showed a similar congener distribution patterns, and C 11 and Cl 7,8 were identified as the dominant carbon and chlorine congener groups. Significant linear relationships were found among different SCCP congener groups (r 2 ≥ 0.9). High concentrations of SCCPs in sewage sludge imply that SCCPs are widely present in China. - Highlights: ► Levels and distribution patterns of SCCPs were studied in sewage sludge in China. ► Concentrations of total SCCPs in sludge ranged from 0.8 to 52.7 μg/g dry weight. ► C 11 and Cl 7,8 were identified as the dominant congener groups within SCCPs. ► Significant linear relationships were found among SCCP congener groups (r 2 ≥ 0.9). ► SCCPs are present in household products and can be exposing to human. - High levels of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China have been found.

  4. Rain events and their effect on effluent quality studied at a full scale activated sludge treatment plant.

    Science.gov (United States)

    Wilén, B M; Lumley, D; Mattsson, A; Mino, T

    2006-01-01

    The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.

  5. Understanding the impact of cationic polyacrylamide on anaerobic digestion of waste activated sludge.

    Science.gov (United States)

    Wang, Dongbo; Liu, Xuran; Zeng, Guangming; Zhao, Jianwei; Liu, Yiwen; Wang, Qilin; Chen, Fei; Li, Xiaoming; Yang, Qi

    2018-03-01

    Previous investigations showed that cationic polyacrylamide (cPAM), a flocculant widely used in wastewater pretreatment and waste activated sludge dewatering, deteriorated methane production during anaerobic digestion of sludge. However, details of how cPAM affects methane production are poorly understood, hindering deep control of sludge anaerobic digestion systems. In this study, the mechanisms of cPAM affecting sludge anaerobic digestion were investigated in batch and long-term tests using either real sludge or synthetic wastewaters as the digestion substrates. Experimental results showed that the presence of cPAM not only slowed the process of anaerobic digestion but also decreased methane yield. The maximal methane yield decreased from 139.1 to 86.7 mL/g of volatile suspended solids (i.e., 1861.5 to 1187.0 mL/L) with the cPAM level increasing from 0 to 12 g/kg of total suspended solids (i.e., 0-236.7 mg/L), whereas the corresponding digestion time increased from 22 to 26 d. Mechanism explorations revealed that the addition of cPAM significantly restrained the sludge solubilization, hydrolysis, acidogenesis, and methanogenesis processes. It was found that ∼46% of cAPM was degraded in the anaerobic digestion, and the degradation products significantly affected methane production. Although the theoretically biochemical methane potential of cPAM is higher than that of protein and carbohydrate, only 6.7% of the degraded cPAM was transformed to the final product, methane. Acrylamide, acrylic acid, and polyacrylic acid were found to be the main degradation metabolites, and their amount accounted for ∼50% of the degraded cPAM. Further investigations showed that polyacrylic acid inhibited all the solubilization, hydrolysis, acidogenesis, and methanogenesis processes while acrylamide and acrylic acid inhibited the methanogenesis significantly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Examination into the gamma irradiation of activated sludge

    International Nuclear Information System (INIS)

    Mustapha, S.; Forster, C.F.

    1985-01-01

    This study has shown that the treatment of activated sludge by gamma irradiation resulted in a deterioration in the filterability, a decrease in the size of the floc particles and an increase in the organic matter present in the sludge supernatant. A significant difference was found between the results obtained for filamentous and non-filamentous sludges in relation to the amount of soluble polysaccharide produced. (author)

  7. Effect of ultrasonic specific energy on waste activated sludge ...

    African Journals Online (AJOL)

    The effect of ultrasonic specific energy on waste activated sludge (WAS) solubilization and enzyme activity was investigated in this study. Experimental results showed that the increase of ultrasonic specific energy in the range of 0 - 90000 kJ/kg dried sludge (DS) benefited WAS particle size reduction and the solubilization ...

  8. Determination of the kinetic and stoichiometric constant in a conventional bioreactor of activated sludge, to scale

    International Nuclear Information System (INIS)

    Rodriguez Chaparro, Tatiana; Perez Navarrete, Eddie Albert; Vivas Mora, Eneydi

    2003-01-01

    The activated sludge process is the one of the most efficient process, when it comes to removal of organic matter. Implementing in the lab is quite easy, economic technically feasible, and simultaneously offers the possibility of using the results obtained in the lab to be applied in field by determining the kinetic and stoichiometric constants. The activated sludge system was designed, built and operated in the water quality lab, at the Military University in Bogota, Colombia. The bioreactor has an aeration chamber, a sedimentation tank and a feeding source with wastewater taken from a meat packing plant in Bogota. The research was carried out for 3 months, in two stages as follows: in the first stage and in order to obtain a high concentration of biomass the acclimatizing process was carried out. This step allows the bioreactor to run in a continuous flow. In the second stage, the bioreactor was taken in to operation and fed with the acclimated sludge at different sludge ages. This would allow us to determine the kinetics, and the stoichiometric constants. The bioreactor was run with a hydraulic retention time of 8 hours and for different sludge ages (5, 10, and 15 days). The system was monitored with a daily grab samples, and pH, temperature as well as the DBO 5 and suspended volatile solids were terminated

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

    International Nuclear Information System (INIS)

    Ragsdale, R.G., Jr.

    1994-12-01

    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. Biodiesel production from the lipid of wastewater sludge using an acidic heterogeneous catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Siddiquee, M.N.; Kazemian, H.; Rohani, S. [University of Western Ontario, Department of Chemical and Biochemical Engineering, London, ON (Canada)

    2011-12-15

    The production of biodiesel from the lipid of wastewater sludge was studied using SBA-15 impregnated with the heteropolyacid H{sub 3}PO{sub 4}.12WO{sub 3}.xH{sub 2}O (PW{sub 12}) as a mesoporous heterogeneous catalyst. X-ray diffraction, Brunauer-Emmett-Teller surface area, thermalgravimetric analysis, and scanning electron microscopy were applied to characterize the prepared catalysts. Catalytic performances were evaluated in a microreactor setup under different experimental conditions. The biodiesel yield for a sample impregnated with 15 % PW{sub 12} was 30.14 wt-% at a temperature of 135 C and a pressure of 135 psi for 3 h reaction time. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Toxicity of di-(2-ethylhexyl) phthalate on the anaerobic digestion of wastewater sludge

    DEFF Research Database (Denmark)

    Alatriste-Mondragon, Felipe; Iranpour, R.; Ahring, Birgitte Kiær

    2003-01-01

    Previous studies on the microbial degradation of individual phthalic acid esters (PAEs) have demonstrated that the compounds with short ester hydrocarbon chains are easily biodegraded and mineralized, but PAEs with long ester chains are less susceptible to degradation and some of them...... Bureau of Sanitation's Hyperion Treatment Plant. Di (2-ethylhexyl) phthalate (DEHP), the most common persistent PAE found in wastewater, and di-n-butyl phthalate (DBP), a common PAE with short ester chains, were sorbed into the sludge fed to a bench-scale digester for a period of 12 weeks. DEHP...... degradation was always poor, and accumulation of DEHP was correlated with inhibition of the microbial degradation of DBP and with process instability of the test digester. Inhibition of the DBP removal was completely reversed after DEHP addition was discontinued, but biogas production never recovered...

  12. Hydrogen sulfide formation control and microbial competition in batch anaerobic digestion of slaughterhouse wastewater sludge: Effect of initial sludge pH.

    Science.gov (United States)

    Yan, Li; Ye, Jie; Zhang, Panyue; Xu, Dong; Wu, Yan; Liu, Jianbo; Zhang, Haibo; Fang, Wei; Wang, Bei; Zeng, Guangming

    2018-07-01

    High sulfur content in excess sludge impacts the production of biomethane during anaerobic digestion, meanwhile leads to hydrogen sulfide (H 2 S) formation in biogas. Effect of initial sludge pH on H 2 S formation during batch mesophilic anaerobic digestion of slaughterhouse wastewater sludge was studied in this paper. The results demonstrated that when the initial sludge pH increased from 6.5 to 8.0, the biogas production increased by 10.1%, the methane production increased by 64.1%, while the H 2 S content in biogas decreased by 44.7%. The higher initial sludge pH inhibited the competition of sulfate-reducing bacteria with methane-producing bacteria, and thus benefitted the growth of methanogens. Positive correlation was found between the relative abundance of Desulfomicrobium and H 2 S production, as well as the relative abundance of Methanosarcina and methane production. More sulfates and organic sulfur were transferred to solid and liquid rather than H 2 S formation at a high initial pH. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. 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.

    2017-03-01

    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

  14. Electro-dewatering of wastewater sludge: influence of the operating conditions and their interactions effects.

    Science.gov (United States)

    Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

    2011-04-01

    Electric field-assisted dewatering, also called electro-dewatering (EDW), is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. The application of these additional fields can be applied to either or both dewatering stages (filtration and/or compression), or as a pre-or post-treatment of the dewatering process. In this study, the performance of the EDW on wastewater sludge was investigated. Experiments were carried out on a laboratory filtration/compression cell, provided with electrodes, in order to apply an electrical field. The chosen operating conditions pressure (200-1200 kPa) and voltage (10-50 V) are sufficient to remove a significant proportion of the water that cannot be removed using mechanical dewatering technologies alone. A response surface methodology (RSM) was used to evaluate the effects of the processing parameters of EDW on (i) the final dry solids content, which is a fundamental dewatering parameter and an excellent indicator of the extent of EDW and (ii) the energy consumption calculated for each additional mass of water removed. A two-factor central composite design was used to establish the optimum conditions for the EDW of wastewater sludge. Experiments showed that the use of an electric field combined with mechanical compression requires less than 10 and 25% of the theoretical thermal drying energy for the low and moderate voltages cases, respectively. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Patel, Hema; Pandey, Suneel

    2012-01-01

    Highlights: ► Stabilization/solidification of chemical sludge from textile wastewater treatment plants using Portland Pozzolona Cement (PPC) containing fly ash. ► Physical engineering (compressive strength and block density) indicates that sludge has potential to be reused for construction purpose after stabilization/solidification. ► Leaching of heavy metals from stabilized/solidified materials were within stipulated limits. ► 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 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.

  16. Removal of odorous materials in carbonization process of dyeing wastewater sludge

    International Nuclear Information System (INIS)

    Bae, Sung-Keun; Woo, Byung-Kyu; Nam, In-Sick; Lee, Joo-Yong; Kim, Gi-Sun

    2010-01-01

    From drying process in a carbonization facility of dyeing wastewater sludge, noxious and odorous materials such as NH 3 , H 2 S, and Volatile Organic Compound (VOCs) contained in the sludge are emitted. In previous studies Regenerative Thermal Oxidizer (RTO) was verified as the most efficient method to eliminate them; nevertheless, it was very expensive to establish and operate because of fuel consumption. To estimate the feasibility of a water spray tower and bio-filter system, laboratory scale experiments for NH 3 , H 2 S, and toluene gas carried out. In case of water spray experiment for the single gas, the removal rate of NH 3 and H 2 S increased as decreasing the concentration, increasing the liquid/ gas ratio, and increasing the retention time. Toluene was eliminated as low as 20% regardless of the above operating parameters. The removal rates of NH 3 and H 2 S were 88∼98% and 80∼83%, respectively. For the mixed gas, the removal rates of NH 3 and toluene was a little dropped, but H 2 S was eliminated slightly more as compared with single gas experiment. Water spray system was not effective for toluene, but it was removed over 90% in bio-filter system. Retention time of gas in bio-filter bed might be an important operating parameter and its optimal condition was considered to 60 seconds. It is experimentally verified that odorous material was very effectively removed by a water spray tower and bio-filter combined system. (author)

  17. A solidification/stabilization process for wastewater treatment sludge from a primary copper smelter

    Directory of Open Access Journals (Sweden)

    Ivšić-Bajčeta Dragana

    2013-01-01

    Full Text Available Wastewater treatment sludge from primary copper smelter is characterized as hazardous waste that requires treatment prior disposal due to significant amount of heavy metals and arsenic. The aim of the presented study was to investigate the feasibility and the effectiveness of solidification/stabilization process of the sludge using fly ash and lime as binders. The effectiveness of the process was evaluated by Unconfined Compressive Strength (UCS testing, leaching tests (EN 12457-4 and Toxicity Characteristic Leaching Procedure (TCLP and Acid Neutralization Capacity (ANC test. All samples reached target UCS of 0.35 MPa. Calcium to silicon concentration ratio (cCa/cSi, determined by X-Ray Fluorescence (XRF analysis, was identified as main factor governing strength development. Inductively coupled plasma-optical emission spectrometry (ICP-OES analyses of solutions after leaching tests showed excellent stabilization of Cu, Ni, Pb and Zn (above 99 % and arsenic (above 90 % in samples with high Ca(OH2 content. Results of ANC test indicated that buffering capacity of solidified material linearly depended on Ca concentration in FA and lime. Sample with 20 % of binder heaving 50 % of FA and 50 % of lime met all requirements to be safely disposed. [Projekat Ministarstva nauke Republike Srbije, br. 34033

  18. Use of lignite fly ash as an additive in alkaline stabilisation and pasteurisation of wastewater sludge

    Energy Technology Data Exchange (ETDEWEB)

    Kocaer, F.O.; Alkan, U.; Baskaya, H.S. [Uludag University, Bursa (Turkey). Faculty of Engineering & Architecture

    2003-10-01

    The possibility of using lignite fly ash in low doses for reducing the pathogen levels in wastewater sludge was investigated. The results showed that using fly ash alone in doses of 40%,80% and 120% (on a dry weight basis), did not produce an alkaline environment for an efficient removal of pathogens. However, using fly ash in conjunction with the minimum amount of quicklime may act as an effective way of fecal coliform removal in both alkaline stabilisation and pasteurisation processes. It was shown that using fly ash in doses of 80% and 120% in alkaline stabilisation and pasteurisation processes prevented the pH decays and regrowth of pathogens during 60 days of storage period. The results of the study confirmed that alkaline pasteurisation process produces a product which is more resistant to pH decays and regrowth of fecal coliforms compared to that of alkaline stabilisation. Consequently, the overall results of this study indicated that the minimum lime and fly ash dosages required to generate a Class B biosolid were 10-15% and 80%, respectively. On the other hand, heating sludge to 50{degree}C prior to the addition of 10-15% quicklime and 80% fly ash followed by further heating to 70{degree}C and then sustaining at this temperature for 30 minutes were sufficient to generate a Class A biosolid.

  19. Seawater-based wastewater accelerates development of aerobic granular sludge: A laboratory proof-of-concept.

    Science.gov (United States)

    Li, Xiling; Luo, Jinghai; Guo, Gang; Mackey, Hamish R; Hao, Tianwei; Chen, Guanghao

    2017-05-15

    This study aimed to develop an aerobic granular sludge process for the efficient treatment of highly saline wastewater and understand the granulation process in a seawater-based multi-ion matrix. Five identical sequencing batch airlift reactors (SBARs) are used to treat synthetic saline sewage with different proportions of real seawater (0%-100%). The results confirm that aerobic granular sludge can be successfully developed with various proportions of seawater up to 100% and show that seawater not only significantly accelerates granulation but also generates stronger granular structures than does freshwater. The increased presence of gel-forming alginate-like exopolysaccharides in the granules explains why a greater proportion of seawater leads to higher density and improves the cohesive strength of the granules. SEM-EDX analysis further revealed substantial presence of both Ca 2+ and Mg 2+ phosphate in the granule core as well as in the outer layers providing extra bridging forces in addition to alginate-like exopolysaccharides for accelerating the granule formation and maintaining the structure. It is hoped that this work could explore another approach for saline sewage treatment and bring some clues for the mystery of granulation mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Influence of different anoxic time exposures on active biomass, protozoa and filamentous bacteria in activated sludge.

    Science.gov (United States)

    Rodriguez-Perez, S; Fermoso, F G; Arnaiz, C

    Medium-sized wastewater treatment plants are considered too small to implement anaerobic digestion technologies and too large for extensive treatments. A promising option as a sewage sludge reduction method is the inclusion of anoxic time exposures. In the present study, three different anoxic time exposures of 12, 6 and 4 hours have been studied to reduce sewage sludge production. The best anoxic time exposure was observed under anoxic/oxic cycles of 6 hours, which reduced 29.63% of the biomass production compared with the oxic control conditions. The sludge under different anoxic time exposures, even with a lower active biomass concentration than the oxic control conditions, showed a much higher metabolic activity than the oxic control conditions. Microbiological results suggested that both protozoa density and abundance of filamentous bacteria decrease under anoxic time exposures compared to oxic control conditions. The anoxic time exposures 6/6 showed the highest reduction in both protozoa density, 37.5%, and abundance of filamentous bacteria, 41.1%, in comparison to the oxic control conditions. The groups of crawling ciliates, carnivorous ciliates and filamentous bacteria were highly influenced by the anoxic time exposures. Protozoa density and abundance of filamentous bacteria have been shown as promising bioindicators of biomass production reduction.

  1. INFLUENCE OF SELECTED PHARMACEUTICALS ON ACTIVATED SLUDGE DEHYDROGENASE ACTIVITY

    Directory of Open Access Journals (Sweden)

    Agnieszka Tomska

    2016-06-01

    The aim of this work was to evaluate the effect of selected antibiotics - sulfanilamide and erythromycin on activated sludge dehydrogenase activity with use of trifenyltetrazolinum chloride (TTC test. Dehydrogenases activity is an indicator of biochemical activity of microorganisms present in activated sludge or the ability to degrade organic compounds in waste water. TTC test is particularly useful for the regularity of the course of treatment, in which the presence of inhibitors of biochemical reactions and toxic compounds are present. It was observed that the dehydrogenase activity decreases with the increase of a antibiotics concentration. The lowest value of the dehydrogenase activity equal to 32.4 μmol TF / gMLSS obtained at sulfanilamide concentration 150mg / l. For this sample, an inhibition of dehydrogenase activity was 31%.

  2. Fate of return activated sludge after ozonation: an optimization study for sludge disintegration.

    Science.gov (United States)

    Demir, Ozlem; Filibeli, Ayse

    2012-09-01

    The effects of ozonation on sludge disintegration should be investigated before the application of ozone during biological treatment, in order to minimize excess sludge production. In this study, changes in sludge and supernatant after ozonation of return activated sludge were investigated for seven different ozone doses. The optimum ozone dose to avoid inhibition of ozonation and high ozone cost was determined in terms of disintegration degree as 0.05 g O3/gTS. Suspended solid and volatile suspended solid concentrations of sludge decreased by 77.8% and 71.6%, respectively, at the optimum ozone dose. Ozonation significantly decomposed sludge flocs. The release of cell contents was proved by the increase of supernatant total nitrogen (TN) and phosphorus (TP). While TN increased from 7 mg/L to 151 mg/L, TP increased from 8.8 to 33 mg/L at the optimum ozone dose. The dewaterability and filterability characteristics of the ozonated sludge were also examined. Capillary suction time increased with increasing ozone dosage, but specific resistance to filtration increased to a specific value and then decreased dramatically. The particle size distribution changed significantly as a result of floc disruption at an optimum dose of 0.05 gO3/gTS.

  3. REDUCTION OF EXCESS SLUDGE PRODUCTION IN AN ACTIVATED SLUDGE SYSTEM BASED ON LYSIS-CRYPTIC GROWTH, UNCOUPLING METABOLISM AND FOLIC ACID ADDITION

    Directory of Open Access Journals (Sweden)

    V. F. Velho

    Full Text Available Abstract The following sludge reduction alternatives were tested in wastewater biological reactors: oxic-settling-anaerobic (OSA-process; ultrasonic disintegration (UD; chlorination (CH; 3,3',4',5-tetrachlorosalicylanilide (TCS; and folic acid (FA. Compared to the control system, UD reduced 55% of the sludge production, and greater substrate and nutrient removal efficiency was achieved. CH worsened the sludge settleability and increased the SVI values; the system achieved 25% of sludge reduction. OSA showed 50% and 60% of sludge reduction after 16 and 10 hours under anaerobic conditions, respectively. The observed sludge yield during TCS addition was decreased by 40%, and the sludge settleability worsened. FA presented the highest sludge reduction (75%, and the system improved the nutrient removal efficiency by 30% compared to the control system and maintained the sludge properties. Acute toxicity conducted with Daphnia magna classified the effluent from the sludge reduction systems as non-toxic for discharge into water sources.

  4. Determination of chiral pharmaceuticals and illicit drugs in wastewater and sludge using microwave assisted extraction, solid-phase extraction and chiral liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Evans, Sian E; Davies, Paul; Lubben, Anneke; Kasprzyk-Hordern, Barbara

    2015-07-02

    This is the first study presenting a multi-residue method allowing for comprehensive analysis of several chiral pharmacologically active compounds (cPACs) including beta-blockers, antidepressants and amphetamines in wastewater and digested sludge at the enantiomeric level. Analysis of both the liquid and solid matrices within wastewater treatment is crucial to being able to carry out mass balance within these systems. The method developed comprises filtration, microwave assisted extraction and solid phase extraction followed by chiral liquid chromatography coupled with tandem mass spectrometry to analyse the enantiomers of 18 compounds within all three matrices. The method was successfully validated for 10 compounds within all three matrices (amphetamine, methamphetamine, MDMA, MDA, venlafaxine, desmethylvenlafaxine, citalopram, metoprolol, propranolol and sotalol), 7 compounds validated for the liquid matrices only (mirtazapine, salbutamol, fluoxetine, desmethylcitalopram, atenolol, ephedrine and pseudoephedrine) and 1 compound (alprenolol) passing the criteria for solid samples only. The method was then applied to wastewater samples; cPACs were found at concentration ranges in liquid matrices of: 1.7 ng L(-1) (metoprolol) - 1321 ng L(-1) (tramadol) in influent, sludge: 0.4 ng g(-1) (metoprolol) - 275 ng g(-1) (citalopram). Enantiomeric profiling revealed that studied compounds were present in analysed samples in non-racemic composition. Furthermore, enantiomeric composition of studied analytes differed in liquid and solid matrices. This demonstrates that not analysing the solid fraction of wastewater may lead to over-estimation of the removal rates of cPACs as well as possible misrepresentation of the enantiomeric fraction of the compounds as they leave the wastewater treatment plant. Consequently risks from cPACs entering the environment might be higher than

  5. Effect of TiO2 nanoparticles on UASB biomass activity and dewatered sludge.

    Science.gov (United States)

    Yadav, Tushar; Mungray, Alka A; Mungray, Arvind K

    2017-02-01

    The accumulation of the nanowastes in the wastewater treatment plants has raised several concerns; therefore, it is an utmost priority to study the nanoparticle (NP) toxicity in such systems. In this work, the effect of TiO 2 NPs on up-flow anaerobic sludge blanket (UASB) microflora and their photocatalytic effect on dewatered sludge were studied. We observed 99.98% removal of TiO 2 NPs by sludge biomass within 24 h, though negligible toxicity was found up to 100 mg/L TiO 2 concentration on extracellular polymeric substances (EPS), volatile fatty acid and biogas generation. The low toxicity corresponds to the agglomeration of TiO 2 NPs in UASB sludge. Alterations in dewatered sludge biochemical composition and increase in cell damage were observed upon exposure to sunlight as evidenced by FTIR and fluorescent microscopy, respectively. Results suggest the negligible toxicity of TiO 2 NPs on UASB biomass activity; however, once exposed to open environment and sunlight, they may exert detrimental effects.

  6. Applicability of industrial wastewater as carbon source for denitrification of a sludge dewatering liquor.

    Science.gov (United States)

    Chen, Jiazhong; Lee, Yoomin; Oleszkiewicz, Jan A

    2013-01-01

    The applicability of four industrial waste streams from potato processing, canola processing and oil refining, biodiesel production (glycerol), and glycol as substitutes to methanol and ethanol in denitrification of anaerobically digested sludge dewatering liquor (centrate) was evaluated in bench-scale sequencing batch reactors. It was found that glycerol was the best substitute with the specific denitrification rate (SDNR) of 13 mg NO3-N/(g VSS x h) followed by potato processing wastewater at 12mg NO3-N/(g VSS x h). Both substrates produced faster SDNR than methanol's 10mg NO3-N/(g VSS x h); however, they were inferior to ethanol's 17 mg NO3-N/(g VSS x h). Glycol had SDNR of 8 mg NO3-N/(g VSS x h) and demonstrated a very fast acclimation rate, i.e. the response in increased denitrification rate was visible in three days following glycol addition. Canola processing and oil refining wastewater was considered an inappropriate carbon source due to a low SDNR of 5 mg NO3-N/(g VSS x h) and apparent inhibitory effect on nitrification.

  7. EFFECT OF STARCH ADDITION ON THE PERFORMANCE AND SLUDGE CHARACTERIZATION OF UASB PROCESS TREATING METHANOLIC WASTEWATER

    Science.gov (United States)

    Yan, Feng; Kobayashi, Takuro; Takahashi, Shintaro; Li, Yu-You; Omura, Tatsuo

    A mesophilic(35℃) UASB reactor treating synthetic wastewater containing methanol with addition of starch was continuously operated for over 430 days by changing the organic loading rate from 2.5 to 120kg-COD/m3.d. The microbial community structure of the granules was analyzed with the molecular tools and its metabolic characteristics were evaluated using specific methanogenic activity tests. The process was successfully operated with over 98% soluble COD removal efficiency at VLR 30kg-COD/m3.d for approximately 300 days, and granulation satisfactory proceeded. The results of cloning and fluorescence in situ hybridization analysis suggest that groups related the genus Methanomethylovorans and the genus Methanosaeta were predominant in the reactor although only the genus Methanomethylovorans was predominant in the reactor treating methanolic wastewater in the previous study. Abundance of the granules over 0.5 mm in diameter in the reactor treating methanolic wastewater with addition of starch was 3 times larger than that in the reactor treating methanolic wastewater. Specific methanogenic activity tests in this study indicate that the methanol-methane pathway and the methanol-H2/CO2-methane pathway were predominant, and however, there was a certain level of activity for acetate-methane pathway unlike the reactor treating methanolic wastewater. These results suggest addition of starch might be responsible for diversifying the microbial community and encouraging the granulation.

  8. Anaerobic granular sludge for simultaneous biomethanation of synthetic wastewater and CO with focus on the identification of CO-converting microorganisms

    DEFF Research Database (Denmark)

    Jing, Yuhang; Campanaro, Stefano; Kougias, Panagiotis

    2017-01-01

    to suspended sludge (less than 0.25 atm) as previously reported. Continuous experiments in upflow anaerobic sludge blanket (UASB) reactors showed AGS could efficiently convert synthetic wastewater and CO into methane by applying gas-recirculation. The addition of CO to UASB reactor enhanced...

  9. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants

    NARCIS (Netherlands)

    Temmink, B.G.; Klapwijk, A.

    2004-01-01

    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg/l and at sludge retention times of 10 and 27

  10. Can aquatic worms enhance methane production from waste activated sludge?

    NARCIS (Netherlands)

    Serrano, Antonio; Hendrickx, Tim L.G.; Elissen, Hellen; Laarhoven, Bob; Buisman, Cees J.N.; Temmink, Hardy

    2016-01-01

    Although literature suggests that aquatic worms can help to enhance the methane production from excess activated sludge, clear evidence for this is missing. Therefore, anaerobic digestion tests were performed at 20 and at 30 °C with sludge from a high-loaded membrane bioreactor, the aquatic worm

  11. Heavy metals and polycyclic aromatic hydrocarbons in sludge from three industrial wastewater treatment plants of the industrial parks of Isfahan province

    Directory of Open Access Journals (Sweden)

    Saeed Mardan

    2015-01-01

    Conclusion: The concentration and composition of PAHs and HMs in sewage sludge varied and depended mainly on the quantity and type of industrial wastewater accepted by the WWTPs. There is a pyrene in sewage samples that is a carcinogenic. The concentration of HMs in sewage sludge was above of standard levels. Finally, we are not recommended the using of industrial sewage sludge in agriculture because of the high value of HMs was found in samples.

  12. Bacterial composition of activated sludge - importance for floc and sludge properties

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Per H.; Thomsen, Trine R.; Nielsen, Jeppe L.

    2003-07-01

    Activated sludge flocs consist of numerous constituents which, together with other factors, are responsible for floc structure and floc properties. These properties largely determine the sludge properties such as flocculation, settling and dewaterability. In this paper we briefly review the present knowledge about the role of bacteria in relation to floc and sludge properties, and we present a new approach to investigate the identity and function of the bacteria in the activated sludge flocs. The approach includes identification of the important bacteria and a characterization of their physiological and functional properties. It is carried out by use of culture-independent molecular biological methods linked with other methods to study the physiology and function maintaining a single cell resolution. Using this approach it was found that floc-forming properties differed among the various bacterial groups, e.g. that different microcolony-forming bacteria had very different sensitivities to shear and that some of them deflocculated under anaerobic conditions. in our opinion, the approach to combine identity with functional analysis of the dominant bacteria in activated sludge by in situ methods is a very promising way to investigate correlations between presence of specific bacteria, and floc and sludge properties that are of interest. (author)

  13. Technical-economical, agronomical, pedological, hygienic and normative aspects of municipal wastewater sludges; Aspetti tecnico-economici, agronomici, pedologici, igienico-sanitari e normativi dei fanghi di depurazione civile

    Energy Technology Data Exchange (ETDEWEB)

    Ottavi, C [ENEA, Rome (Italy). Dip. Ambiente; Ottaviani, M [Istituto Superiore di Sanita, Rome (Italy). Lab. di Igiene Ambientale; Figliolia, A [Istituto Sperimentale per la Nutrizione delle Piante, Rome (Italy)

    1995-12-01

    This review is intended to give an overview on the technical, economical, agronomical, pedological and hygienic aspects of sludges from treatment plants of civil wastewater, Both Italian and European regulations on the sludge disposal are considered.

  14. Characterization of sludges of La Golondrina WWTP: sludges as final containers of the domestic wastewater pollution; Caracterizacion de fangos de la EDAR La Golondrina (EMACSA-Cordoba): su funcion como receptores finales de la contaminacion del agua residual urbana

    Energy Technology Data Exchange (ETDEWEB)

    Marin Galvin, R.; Alonso Perez de siles, L.; Rojas Moreno, F. J.

    2005-07-01

    Treatment of wastewater is to concentrate the original pollution in a by-product: the wastewater sludge or bio-solid. As example, La Golondrina WWTP (Cordoba-spain) promotes the production of 1,3 kg of sludge per m''3 of wastewater, yielding logically a treated water according to laws. Furthermore, the treatment process there applied reduces the levels of nine majority metals (Cu, Fe, Mn, Pb, Cd, Ni, Cr, Zn, Hg) from 2,72 mg/l to 1.42 mg/l in the treated water, generating almost, a sludge agrees with the spanish normative to sludge intended to agricultural use (its main fate). Summarizing, the treatment of wastewater supposes the concentration of the original biodegradable load into the sludge around 340 times, while metals exhibited a different concentration degree for each one (from 10.000 times for Fe, u pto 1-2 times for Cd and Hg). Finally, the concentration degree of a metal in the sludge is mainly led by the removed concentration of metal in the treatment process, and after, by the original concentration of metal in the influent wastewater. (Author) 24 refs.

  15. Modeling effects of DO and SRT on activated sludge decay and production.

    Science.gov (United States)

    Liu, Guoqiang; Wang, Jianmin

    2015-09-01

    The effect of dissolved oxygen (DO) on the endogenous decay of active heterotrophic biomass and the hydrolysis of cell debris were studied. With the inclusion of a hydrolysis process for the cell debris, mathematical models that are capable of quantifying the effects of DO and sludge retention time (SRT) on concentrations of active biomass and cell debris in activated sludge are presented. By modeling the biomass cultivated with unlimited DO, the values of endogenous decay coefficient for heterotrophic biomass, the hydrolysis constant of cell debris, and the fraction of decayed biomass that became cell debris were determined to be 0.38 d(-1), 0.013 d(-1), and 0.28, respectively. Results from modeling the biomass cultivated under different DO conditions suggested that the experimental low DO (∼0.2 mg/L) did not inhibit the endogenous decay of heterotrophic biomass, but significantly inhibited the hydrolysis of cell debris with a half-velocity constant value of 2.1 mg/L. Therefore, the increase in sludge production with low DO was mainly contributed by cell debris rather than the active heterotrophic biomass. Maximizing sludge production during aerobic wastewater treatment could reduce aeration energy consumption and improve biogas energy recovery potential. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    Science.gov (United States)

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Effect of Dissolved Air Flotation Process on Thickening of Activated Sludge

    Directory of Open Access Journals (Sweden)

    Atamaleki A.

    2016-12-01

    Full Text Available Abstract Aims: Sludge is an inescapable component of all wastewaters that originated from their treatment. dissolved air flotation (DAF process as an alternative clarifier is used in treatment of drinking water, pretreatment of wastewater, and as a phase separator in sludge activation processes. This study aimed to calibrated the usage of DAF process in a laboratory scale and under various conditions, to achieve the optimum efficiency in recycling the activated sludge. Instrument & Methods: In this experimental study, of Kashan's Shahid Beheshti hospital and immediately transported to the laboratory. The optimal dose of polyaluminum chloride coagulant and pH was determined and then applied in DAF process. Finally turbidity, electrical conductivity (EC and total solids (TS parameters were measured and compared with control sample. Findings: The optimal pH and optimal dose of coagulant were 6.5 and 25mg/l, respectively. Also Optimal process efficiency to reduce EC, TS and turbidity parameters were 23.4, 44.5 and 88%, respectively. Conclusion: Dissolved air flotation process removes the turbidity, EC and TS effectively; however, it has minimal impact on EC and TS.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cristale, Joyce [Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-2, 08034 Barcelona, Catalonia (Spain); Ramos, Dayana D. [Institute of Chemistry, Federal University of Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, CEP 79074-460 Campo Grande, MS (Brazil); Dantas, Renato F. [Department of Chemical Engineering, University de Barcelona, Marti i Franques 1, 08028 Barcelona, Catalonia (Spain); School of Technology, University of Campinas-UNICAMP, Paschoal Marmo 1888, 13484-332 Limeira, SP (Brazil); Machulek Junior, Amilcar [Institute of Chemistry, Federal University of Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, CEP 79074-460 Campo Grande, MS (Brazil); Lacorte, Silvia [Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-2, 08034 Barcelona, Catalonia (Spain); Sans, Carme; Esplugas, Santiago [Department of Chemical Engineering, University de Barcelona, Marti i Franques 1, 08028 Barcelona, Catalonia (Spain)

    2016-01-15

    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{sup −1} to 150 µg L{sup −1}. During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980 ng g{sup −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/H{sub 2}O{sub 2} and O{sub 3}) 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/H{sub 2}O{sub 2} and O{sub 3}. 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. - Highlights: • OPFRs were detected in wastewater and sludge of all studied WWTPs. • Alkyl and chloroalkyl phosphates were present in secondary treatment effluents. • TBOEP, TNBP and TIBP were degraded by UV/H{sub 2}O{sub 2} and O{sub 3} treatment. • TCEP, TCIPP and TDCPP were

  19. An Evaluation of Reed Bed Technology to Dewater Army Wastewater Treatment Plant Sludge

    Science.gov (United States)

    1993-09-01

    speculated that the plants produced "root exudations" that were active against pathogens , and that the plants specifically showed an affinity for cadmium, zinc...mineralize and for pathogens to be destroyed. This downtime makes multiple beds necessary. The USEPA also reports that the major advantage of the reed...employee to regulate the sludge applications. This employee would also visually assess the beds for possible problems such as weed or insect ( aphid

  20. 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.

    2003-07-01

    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.

  1. A xylanase gene directly cloned from the genomic DNA of alkaline wastewater sludge showing application potential in the paper industry.

    Science.gov (United States)

    Zhao, Yanyu; Luo, Huiying; Meng, Kun; Shi, Pengjun; Wang, Guozeng; Yang, Peilong; Yuan, Tiezheng; Yao, Bin

    2011-09-01

    A xylanase gene, aws-2x, was directly cloned from the genomic DNA of the alkaline wastewater sludge using degenerated PCR and modified TAIL-PCR. The deduced amino acid sequence of AWS-2x shared the highest identity (60%) with the xylanase from Chryseobacterium gleum belonging to the glycosyl hydrolase GH family 10. Recombinant AWS-2x was expressed in Escherichia coli BL21 (DE3) and purified to electrophoretic homogeneity. The enzyme showed maximal activity at pH 7.5 and 55 °C, maintained more than 50% of maximal activity when assayed at pH 9.0, and was stable over a wide pH range from 4.0 to 11.0. The specific activity of AWS-2x towards hardwood xylan (beechwood and birchwood xylan) was significantly higher than that to cereal xylan (oat spelt xylan and wheat arabinoxylan). These properties make AWS-2x a potential candidate for application in the pulp and paper industry.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-14

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

  3. Sewage sludge and wastewater fertilisation of Short Rotation Coppice (SRC) for increased bioenergy production - Biological and economic potential

    International Nuclear Information System (INIS)

    Dimitriou, I.; Rosenqvist, H.

    2011-01-01

    Application of municipal residues, e.g. wastewater or sewage sludge, to Short Rotation Coppice (SRC) is among the most attractive methods for attaining environmental and energy goals set for Europe. At current woodchip prices in Sweden, the gross margin for SRC cultivation is positive only if biomass production is >9 t DM/ha yr. The gross profit margin increases (by 39 and 199 EUR/GJ, respectively) if sewage sludge and wastewater are applied to SRC. Application of residues to SRC has proved to be an acceptable alternative treatment method, and the farmer's profit can be markedly increased if compensation is paid for waste treatment. If all available sludge and wastewater were applied to SRC plantations, they could be grown on large agricultural areas in Europe, and c. 6000 PJ of renewable energy could be produced annually. However, a more economical landuse strategy, e.g. the use of more P-rich residues, appears more rational, and is biologically justifiable. (author)

  4. Agronomic properties of wastewater sludge biochar and bioavailability of metals in production of cherry tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Hossain, Mustafa K; Strezov, Vladimir; Chan, K Yin; Nelson, Peter F

    2010-02-01

    This work presents agronomic values of a biochar produced from wastewater sludge through pyrolysis at a temperature of 550 degrees C. In order to investigate and quantify effects of wastewater sludge biochar on soil quality, growth, yield and bioavailability of metals in cherry tomatoes, pot experiments were carried out in a temperature controlled environment and under four different treatments consisting of control soil, soil with biochar; soil with biochar and fertiliser, and soil with fertiliser only. The soil used was chromosol and the applied wastewater sludge biochar was 10tha(-1). The results showed that the application of biochar improves the production of cherry tomatoes by 64% above the control soil conditions. The ability of biochar to increase the yield was attributed to the combined effect of increased nutrient availability (P and N) and improved soil chemical conditions upon amendment. The yield of cherry tomato production was found to be at its maximum when biochar was applied in combination with the fertiliser. Application of biochar was also found to significantly increase the soil electrical conductivity as well as phosphorus and nitrogen contents. Bioavailability of metals present in the biochar was found to be below the Australian maximum permitted concentrations for food. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  5. Sewage sludge and wastewater fertilisation of Short Rotation Coppice (SRC) for increased bioenergy production - Biological and economic potential

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, I. [Department of Crop Production Ecology, Swedish University of Agricultural Sciences, P.O. Box 7043, SE 750 07 Uppsala (Sweden); Rosenqvist, H. [Department of Agriculture-Farming Systems, Technology and Product Quality, Swedish University of Agricultural Sciences, P.O. Box 17, SE-261 21 Billeberga (Sweden)

    2011-02-15

    Application of municipal residues, e.g. wastewater or sewage sludge, to Short Rotation Coppice (SRC) is among the most attractive methods for attaining environmental and energy goals set for Europe. At current woodchip prices in Sweden, the gross margin for SRC cultivation is positive only if biomass production is >9 t DM/ha yr. The gross profit margin increases (by 39 and 199 EUR/GJ, respectively) if sewage sludge and wastewater are applied to SRC. Application of residues to SRC has proved to be an acceptable alternative treatment method, and the farmer's profit can be markedly increased if compensation is paid for waste treatment. If all available sludge and wastewater were applied to SRC plantations, they could be grown on large agricultural areas in Europe, and c. 6000 PJ of renewable energy could be produced annually. However, a more economical landuse strategy, e.g. the use of more P-rich residues, appears more rational, and is biologically justifiable. (author)

  6. Improving efficiency of transport fuels production by thermal hydrolysis of waste activated sludge

    Science.gov (United States)

    Gulshin, Igor

    2017-10-01

    The article deals with issues of transport biofuels. Transport biofuels are an important element of a system of energy security. Moreover, as part of a system it is inextricably linked to the urban, rural or industrial infrastructure. The paper discusses methods of increasing the yield of biogas from anaerobic digesters at wastewater treatment plants. The thermal hydrolysis method was considered. The main advantages and drawbacks of this method were analyzed. The experimental biomass (from SNDOD-bioreactor) and high-organic substrate have been previously studied by respirometry methods. A biomethane potential of the investigated organic substrate has high rates because of substrate composition (the readily biodegradable substrate in the total composition takes about 85%). Waste activated sludge from SNDOD-bioreactor can be used for biofuel producing with high efficiency especially with pre-treatment like a thermal hydrolysis. Further studies have to consider the possibility of withdrawing inhibitors from waste activated sludge.

  7. Effect of Volatile Fatty Acids and Trimethylamine on Denitrification in Activated Sludge

    DEFF Research Database (Denmark)

    Eilersen, Ann Marie; Henze, Mogens; Kløft, Lene

    1995-01-01

    The effect of volatile fatty acids and trimethylamine on denitrification activity of activated sludge was studied in laboratory batch experiments. Formic acid had no effect on the denitrification rates. Acetic acid, n-butyric acid and trimethylamine all enhanced the rates. Acetate is the compound...... wastewaters from fish, potato and onion industries all stimulated denitrification. Reject water from anaerobic treatment of excess sludge had no significant effect on the denitrification processes. For isobutyric, isovaleric and n-valeric acid the undissociated compounds appear to act as the inhibitor...... with the strongest effect, n-butyric acid has a moderate effect, while TMA only have a small effect in stimulating the rates. Propionic, isobutyric, n-valeric, isovaleric and caproic acid inhibit denitrification, nitrate reduction being more inhibited than nitrite reduction. The inhibitor concentration, KI, at which...

  8. Modeling of Activated Sludge Process Using Sequential Adaptive Neuro-fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Mahsa Vajedi

    2014-10-01

    Full Text Available In this study, an adaptive neuro-fuzzy inference system (ANFIS has been applied to model activated sludge wastewater treatment process of Mobin petrochemical company. The correlation coefficients between the input variables and the output variable were calculated to determine the input with the highest influence on the output (the quality of the outlet flow in order to compare three neuro-fuzzy structures with different number of parameters. The predictions of the neuro-fuzzy models were compared with those of multilayer artificial neural network models with similar structure. The comparison indicated that both methods resulted in flexible, robust and effective models for the activated sludge system. Moreover, the root mean square of the error for neuro-fuzzy and neural network models were 5.14 and 6.59, respectively, which means the former is the superior method.

  9. An activated sludge model for xenobiotic organic micro-pollutants (ASM-X)

    DEFF Research Database (Denmark)

    Plósz, Benedek; Lehnberg, K.; Dott, W.

    2010-01-01

    In this paper, we present an evaluation of the process model developed by Plósz et al. (2010a) to predict the fate of antibiotics xenobiotic organic micro-pollutants (XOMs) in activated sludge systems. Instead of spiking the batch reactors with reference substances, observations were made using...... the XOMs content of pre-clarified municipal sewage. Evaluation of the model structure is carried out in dynamic simulations using data obtained in samples taken in a measuring campaign in a full-scale activated sludge wastewater treatment plant (WWTP). Our results suggest that the sorption...... deteriorate; thereby hindering the effluent quality of secondary treatment step, and thereby increasing the XOM mass load on the tertiary treatment step. Besides the impact of different redox conditions, divalent iron-salt dosing used for enhanced phosphorus removal and pH have been identified as potential...

  10. Photocatalytic Activity of TiO2 Thin Films Obtained by the Sputtering RF in Wastewater

    Science.gov (United States)

    Cardona Bedoya, Jairo Armando; Sanchez Velandia, Wilmer Asmed; Delgado Rosero, Miguel Iban; Florido Cuellar, Alex Enrique; Zelaya Angel, Orlando; Mendoza Alvarez, Julio G.

    2011-03-01

    The photocatalytic activity of Ti O2 thin films in wastewater, under an UV irradiation, is studied. The films were prepared on corning glass substrates by the sputtering RF technique. We present evidence on the photocatalytic degradation, carried out by advanced oxidation processes (AOPs) in domestic wastewater pretreated with UASB (upflow anaerobic sludge blanket) reactors. Ti O2 films were illuminated with ultraviolet light during a time of 4 hours (λ ≅ 264 nm). We could see the effect of degraded operation in the absorbance measurement using UV-VIS spectrophotometry. The results show an increased rate of degradation of the wastewater by 30% compared to the values reflected biologically treated wastewater by anaerobic reactors.

  11. Preparation of thiol-functionalized activated carbon from sewage sludge with coal blending for heavy metal removal from contaminated water.

    Science.gov (United States)

    Li, Juan; Xing, Xing; Li, Jiao; Shi, Mei; Lin, Aijun; Xu, Congbin; Zheng, Jianzhong; Li, Ronghua

    2018-03-01

    Sewage sludge produced from wastewater treatment is a pressing environmental issue. Mismanagement of the massive amount of sewage sludge would threat our valuble surface and shallow ground water resources. Use of activated carbon prepared from carbonization of these sludges for heavy metal removal can not only minimize and stabilize these hazardous materials but also realize resources reuse. In this study, thiol-functionalized activated carbon was synthesized from coal-blended sewage sludge, and its capacity was examined for removing Cu(II), Pb(II), Cd(II) and Ni(II) from water. Pyrolysis conditions to prepare activated carbons from the sludge and coal mixture were examined, and the synthesized material was found to achieve the highest BET surface area of 1094 m 2 /g under 500 °C and 30 min. Batch equilibrium tests indicated that the thiol-functionalized activated carbon had a maximum sorption capacity of 238.1, 96.2, 87.7 and 52.4 mg/g for Pb(II), Cd(II), Cu(II) and Ni(II) removal from water, respectively. Findings of this study suggest that thiol-functionalized activated carbon prepared from coal-blended sewage sludge would be a promising sorbent material for heavy metal removal from waters contaminated with Cu(II), Pb(II), Cd(II) and Ni(II). Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.

    1999-01-01

    The Activated Sludge Model No. 2d (ASM2d) presents a model for biological phosphorus removal with simultaneous nitrification-denitrification in activated sludge systems. ASM2d is based on ASM2 and is expanded to include the denitrifying activity of the phosphorus accumulating organisms (PAOs......). This extension of ASM2 allows for improved modeling of the processes, especially with respect to the dynamics of nitrate and phosphate. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  13. A novel conditioning process for enhancing dewaterability of waste activated sludge by combination of zero-valent iron and persulfate.

    Science.gov (United States)

    Zhou, Xu; Wang, Qilin; Jiang, Guangming; Liu, Peng; Yuan, Zhiguo

    2015-06-01

    Improvement of sludge dewaterability is crucial for reducing the costs of sludge disposal in wastewater treatment plants. This study presents a novel conditioning method for improving waste activated sludge dewaterability by combination of persulfate and zero-valent iron. The combination of zero-valent iron (0-30g/L) and persulfate (0-6g/L) under neutral pH substantially enhanced the sludge dewaterability due to the advanced oxidization reactions. The highest enhancement of sludge dewaterability was achieved at 4g persulfate/L and 15g zero-valent iron/L, with which the capillary suction time was reduced by over 50%. The release of soluble chemical oxygen demand during the conditioning process implied the decomposition of sludge structure and microorganisms, which facilitated the improvement of dewaterability due to the release of bound water that was included in sludge structure and microorganism. Economic analysis showed that the proposed conditioning process with persulfate and ZVI is more economically favorable for improving WAS dewaterability than classical Fenton reagent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system.

    Science.gov (United States)

    Tanikawa, D; Syutsubo, K; Hatamoto, M; Fukuda, M; Takahashi, M; Choeisai, P K; Yamaguchi, T

    2016-01-01

    A pilot-scale experiment of natural rubber processing wastewater treatment was conducted using a combination system consisting of a two-stage up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactor for more than 10 months. The system achieved a chemical oxygen demand (COD) removal efficiency of 95.7% ± 1.3% at an organic loading rate of 0.8 kg COD/(m(3).d). Bacterial activity measurement of retained sludge from the UASB showed that sulfate-reducing bacteria (SRB), especially hydrogen-utilizing SRB, possessed high activity compared with methane-producing bacteria (MPB). Conversely, the acetate-utilizing activity of MPB was superior to SRB in the second stage of the reactor. The two-stage UASB-DHS system can reduce power consumption by 95% and excess sludge by 98%. In addition, it is possible to prevent emissions of greenhouse gases (GHG), such as methane, using this system. Furthermore, recovered methane from the two-stage UASB can completely cover the electricity needs for the operation of the two-stage UASB-DHS system, accounting for approximately 15% of the electricity used in the natural rubber manufacturing process.

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

    Directory of Open Access Journals (Sweden)

    Gouveia R.

    2000-01-01

    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 %.

  16. Effect of process variables on the production of Polyhydroxyalkanoates by activated sludge

    Directory of Open Access Journals (Sweden)

    Mokhtarani Nader

    2012-09-01

    Full Text Available Abstract Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge and determining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogen ratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is much lower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  17. Effect of Process Variables on the Production of Polyhydroxyalkanoates by Activated Sludge

    Directory of Open Access Journals (Sweden)

    Nader Mokhtarani

    2012-09-01

    Full Text Available Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge anddetermining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogenratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is muchlower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  18. Fate and behaviour of ZnO engineered nanoparticles in a simulated domestic wastewater treatment plant

    CSIR Research Space (South Africa)

    Chaúquea, EFC

    2013-08-01

    Full Text Available Wastewater treatment plants (WWTPs) employ activated sludge processes to treat domestic wastewater using a consortium of bacteria essentially to degrade organic matter. However, bacteria activity is inhibited by toxic substances; thus, potentially...

  19. Towards better environmental performance of wastewater sludge treatment using endpoint approach in LCA methodology

    Directory of Open Access Journals (Sweden)

    Isam Alyaseri

    2017-03-01

    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

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

    African Journals Online (AJOL)

    DRINIE

    2003-07-03

    Jul 3, 2003 ... separation, on-site applications of such processes (especially fat traps) are often ... edible oil effluent treatment on sludge settleability, floc structure and activity of .... Poor FOG removal was noted in the MLE system as just 7%.

  1. Evaluation of Control Parameters for the Activated Sludge Process

    Science.gov (United States)

    Stall, T. Ray; Sherrard, Josephy H.

    1978-01-01

    An evaluation of the use of the parameters currently being used to design and operate the activated sludge process is presented. The advantages and disadvantages for the use of each parameter are discussed. (MR)

  2. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal; Lens, Piet Nl L

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether

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

    Science.gov (United States)

    Silva, Cynthia C; Hayden, Helen; Sawbridge, Tim; Mele, Pauline; Kruger, Ricardo H; Rodrigues, Marili Vn; Costa, Gustavo Gl; Vidal, Ramon O; Sousa, Maíra P; Torres, Ana Paula R; Santiago, Vânia Mj; Oliveira, Valéria M

    2012-03-27

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

  4. Distribution of PCDD/Fs and organometallic compounds in sewage sludge of wastewater treatment plants in China

    International Nuclear Information System (INIS)

    Lu Mang; Wu Xuejiao; Zeng Decai; Liao Yong

    2012-01-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), organotin and organolead compounds were measured in sewage sludge samples collected from 24 wastewater treatment plants from 18 cities of 13 provinces in China. Total international toxicity equivalent (I-TEQ) values were evaluated for PCDD/Fs. The total concentration of PCDD/Fs ranged from 104.0 to 1661 pg/g dry weight (d.w.) and 2.51–75.21 pg I-TEQ/g d.w., indicating that all I-TEQs were below Chinese legislation limit value regulated for land application. The concentrations ranged from 258 to 3886, 126 to 1129, and 84–2133 ng/g as Sn d.w., for tributyltin (TBT), dibutyltin (DBT), and diphenyltin (DPhT), respectively. On the other side, organolead concentrations ranged from 85 to 668 with an average of 279 ng/g as lead. High concentrations of organolead compounds in sewage sludge indicated that the environmental impact of organolead compounds remains in China. - Highlights: ► The first study on PCDD/F distribution in sewage sludge in China on a national scale. ► The first study on organometallic compounds distribution in sewage sludge on a national scale. ► The persistence of tetraethyllead deserves attention. - This is the first study on the survey of the distributions of POPs and organometallic compounds in sewage sludge in China on a national scale.

  5. Levels and distribution patterns of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China.

    Science.gov (United States)

    Zeng, Lixi; Wang, Thanh; Ruan, Ting; Liu, Qian; Wang, Yawei; Jiang, Guibin

    2012-01-01

    Short chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutant candidates in the Stockholm Convention and are receiving more and more attentions worldwide. In general, concentrations of contaminants in sewage sludge can give an important indication on their pollution levels at a local/regional basis. In this study, SCCPs were investigated in sewage sludge samples collected from 52 wastewater treatment plants in China. Concentrations of total SCCPs (ΣSCCPs) in sludge were in the range of 0.80-52.7 μg/g dry weight (dw), with a mean value of 10.7 μg/g dw. Most of SCCPs in the sludge samples showed a similar congener distribution patterns, and C(11) and Cl(7,8) were identified as the dominant carbon and chlorine congener groups. Significant linear relationships were found among different SCCP congener groups (r(2) ≥ 0.9). High concentrations of SCCPs in sewage sludge imply that SCCPs are widely present in China. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. 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.

    2003-07-01

    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)

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

    Science.gov (United States)

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

    2014-10-01

    Differential filtration was used to measure silver (>2 nm) entering and leaving nine sewage treatment plants (STPs). The mean concentration of colloidal (2-450 nm) silver, which includes nanosilver, was found to be 12 ng L(-1) in the influent and 6 ng L(-1) in the effluent. For particulate silver (>450 nm) the mean values were 3.3 μg L(-1) for influent and 0.08 μg L(-1) for effluent. Thus, removal was around 50% and 98% for colloidal and particulate silver respectively. There was no significant difference in performance between the different types of STP investigated (three examples each of activated sludge, biological filter and biological filter with tertiary treatment located across England, UK). In addition, treated sewage sludge samples (biosolids) were taken from several STPs to measure the total silver likely to be discharged to soils. Total silver was 3-14 mg kg(-1) DW in the sludge (median 3.6), which if the sludge were added at the recommended rate to soil, would add 11 μg kg(-1) yr(-1) to the top 20 cm soil layer. Predicted concentrations using the LF2000-WQX model for all the rivers of England and Wales for nanosilver were typically in the 0-1 ng L(-1) range but levels up to 4 ng L(-1) are possible in a high discharge and low flow scenario. Predicted concentrations for the total particulate forms were mostly below 50 ng L(-1) except for a high discharge and low flow scenario where concentrations could reach 135 ng L(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. DETERMINATION OF ACTIVATED SLUDGE MODEL ASDM PARAMETERS FOR WASTE WATER TREATMENT PLANT OPERATING IN THE SEQUENTIAL–FLOW TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-01-01

    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.

  9. Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance following Toxic Shock Loading

    KAUST Repository

    Saikaly, Pascal

    2010-12-14

    Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30 min IC50 or the concentration of toxicant that results in a 50% reduction in oxygen utilization rate compared to a referential state represented by a control receiving no toxicant. Biodiversity of dominant bacterial taxa was assessed using polymerase chain reaction-terminal restriction fragment length polymorphism (PCR-T-RFLP) targeting the 16S ribosomal RNA (16S rRNA) gene. Statistical analysis of 30 min IC50 values and PCR-T-RFLP data showed a significant positive correlation (P<0.05) between functional resistance and microbial diversity for each of the three toxicants tested. To our knowledge, this is the first study showing a positive correlation between biodiversity of dominant bacterial taxa in activated sludge and functional resistance. In this system, activated sludge bacterial communities with higher biodiversity are functionally more resistant to disturbance caused by toxic shock loading. © 2010 Springer Science+Business Media, LLC.

  10. Feedforward neural network model estimating pollutant removal process within mesophilic upflow anaerobic sludge blanket bioreactor treating industrial starch processing wastewater.

    Science.gov (United States)

    Antwi, Philip; Li, Jianzheng; Meng, Jia; Deng, Kaiwen; Koblah Quashie, Frank; Li, Jiuling; Opoku Boadi, Portia

    2018-06-01

    In this a, three-layered feedforward-backpropagation artificial neural network (BPANN) model was developed and employed to evaluate COD removal an upflow anaerobic sludge blanket (UASB) reactor treating industrial starch processing wastewater. At the end of UASB operation, microbial community characterization revealed satisfactory composition of microbes whereas morphology depicted rod-shaped archaea. pH, COD, NH 4 + , VFA, OLR and biogas yield were selected by principal component analysis and used as input variables. Whilst tangent sigmoid function (tansig) and linear function (purelin) were assigned as activation functions at the hidden-layer and output-layer, respectively, optimum BPANN architecture was achieved with Levenberg-Marquardt algorithm (trainlm) after eleven training algorithms had been tested. Based on performance indicators such the mean squared errors, fractional variance, index of agreement and coefficient of determination (R 2 ), the BPANN model demonstrated significant performance with R 2 reaching 87%. The study revealed that, control and optimization of an anaerobic digestion process with BPANN model was feasible. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Performance evaluation of a mesophilic (37 deg. C) upflow anaerobic sludge blanket reactor in treating distiller's grains wastewater

    International Nuclear Information System (INIS)

    Gao Mengchun; She Zonglian; Jin Chunji

    2007-01-01

    The performance of a laboratory-scale upflow anaerobic sludge blanket (UASB) reactor treating distiller's grains wastewater was investigated for 420 days at 37 deg. C. After a successful start-up, 80-97.3% chemical oxygen demand (COD) removal efficiencies were achieved at hydraulic retention times (HRT) of 82-11 h with organic loading rates (OLR) of 5-48.3 kg COD m -3 d -1 . The biogas mainly consisted of methane and carbon dioxide, and the methane and carbon dioxide content in the biogas was 57-60 and 38-41%, respectively. The yield coefficient of methane production was 0.3182 l CH 4 g -1 COD removed until OLR at 33.3 kg COD m -3 d -1 , but afterwards began to decrease. The volatile fatty acid (VFA) in the effluent mainly consisted of acetate and propionate, accounting for more than 95% of total VFA as COD, and other VFA was detected at insignificant concentrations. The mesophilic granules developed in this study showed an excellent specific methanogenic activity (SMA) at 0.91 and 1.12 g methane COD g -1 VSS -1 d -1 using sucrose and acetate as individual substrates on day 200, respectively

  12. A novel rotation generator of hydrodynamic cavitation for waste-activated sludge disintegration.

    Science.gov (United States)

    Petkovšek, Martin; Mlakar, Matej; Levstek, Marjetka; Stražar, Marjeta; Širok, Brane; Dular, Matevž

    2015-09-01

    The disintegration of raw sludge is very important for enhancement of the biogas production in anaerobic digestion process as it provides easily degradable substrate for microorganisms to perform maximum sludge treatment efficiency and stable digestion of sludge at lower costs. In the present study the disintegration was studied by using a novel rotation generator of hydrodynamic cavitation (RGHC). At the first stage the analysis of hydrodynamics of the RGHC were made with tap water, where the cavitation extent and aggressiveness was evaluated. At the second stage RGHC was used as a tool for pretreatment of a waste-activated sludge (WAS), collected from wastewater treatment plant (WWTP). In case of WAS the disintegration rate was measured, where the soluble chemical oxygen demand (SCOD) and soluble Kjeldahl nitrogen were monitored and microbiological pictures were taken. The SCOD increased from initial 45 mg/L up to 602 mg/L and 12.7% more biogas has been produced by 20 passes through RGHC. The results were obtained on a pilot bioreactor plant, volume of 400 L. Copyright © 2015. Published by Elsevier B.V.

  13. Influence of cations on the partition behavior of perfluoroheptanoate (PFHpA) and perfluorohexanesulfonate (PFHxS) on wastewater sludge.

    Science.gov (United States)

    Wang, Fei; Shih, Kaimin; Ma, Ruowei; Li, Xiao-yan

    2015-07-01

    The effects of different cations on the sorption behavior of PFHpA and PFHxS on two types of sludge were investigated in this study. The sodium and potassium ions did not significantly affect PFHpA and PFHxS sorption on different sludge. For calcium and magnesium, the sorption amount of PFAS increased with calcium and magnesium concentration increasing from 1 to 30 mM and then decreased with those increasing from 30 to 100 mM. The sorption level of PFHxS or PFHpA greatly increased with increasing Al3+ and Fe3+ cation concentrations due to the strong sorption and coagulation effects by the formation of aluminum hydroxide (or ferric hydroxide) colloids or precipitates. After the organics in sludge has been removed by thermal treatment, the PFAS sorption on sludge was greatly reduced. Such finding indicated that sorption to organic matter is more important for anionic PFASs than adsorption to mineral surfaces. However, due to the higher content of biological organics, a secondary activated sludge has higher affinity toward PFAS species than chemically enhanced primary treatment sludge. It indicated that the organic types in sludge were also crucial to the sorption levels of PFASs by sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. COMPARISON BETWEEN DIFFERENT MODELS FOR RHEOLOGICAL CHARACTERIZATION OF ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    A. H. Khalili Garakani

    2011-09-01

    Full Text Available Activated sludge flow rheology is a very complicated phenomenon. Studies related to activated sludge tend to classify sludge as non-Newtonian fluid. Until now, several theories have been built to describe the complex behavior of activated sludge with varying degrees of success. In this article, seven different models for viscosity of non-Newtonian fluids (i.e., Power law, Bingham plastic, Herschel-Bulkley, Casson, Sisko, Carreau and Cross were considered to evaluate their predictive capability of apparent viscosity of activated sludge. Results showed that although evaluating the constants in the four-parameter models is difficult, they provide the best prediction of viscosity in the whole range of shear rates for activated sludge. For easier prediction of viscosity at different mixed liquor suspended solids (2.74-31g/L, temperature (15-25°C and shear rate (1-1000/s, simple correlations were proposed. Comparing the results with the experimental data revealed that the proposed correlations are in good agreement with real apparent viscosities.

  15. Mesophilic and thermophilic anaerobic co-digestion of winery wastewater sludge and wine lees: An integrated approach for sustainable wine production.

    Science.gov (United States)

    Da Ros, C; Cavinato, C; Pavan, P; Bolzonella, D

    2017-12-01

    In this work, winery wastes generated by a cellar producing approximately 300,000 hL of wine per year was monitored for a period of one year. On average, 196 L of wastewater, 0.1 kg of waste activated sludge (dry matter) and 1.6 kg of wine lees were produced per hectoliter of wine produced. Different winery wastes, deriving from different production steps, namely waste activated sludge from wastewater treatment and wine lees, were co-treated using an anaerobic digestion process. Testing was conducted on a pilot scale for both mesophilic and thermophilic conditions. The process was stable for a long period at 37 °C, with an average biogas production of 0.386 m 3 /kg COD fed . On the other hand, for thermophilic conditions, volatile fatty acids accumulated in the reactor and the process failed after one hydraulic retention time (23 days). In order to fix the biological process, trace elements (iron, cobalt and nickel) were added to the feed of the thermophilic reactor. Metals augmentation improved process stability and yields at 55 °C. The pH ranged between 7.8 and 8.0, and specific gas production was 0.450 m 3 /kg COD fed , which corresponded to dry matter and COD removals of 34% and 88%, respectively. Although the observed performances in terms of biogas production were good, the thermophilic process exhibited some limitations related to both the necessity of metals addition and the worse dewaterability properties. In fact, while the mesophilic digestates reached a good dewatering quality via the addition of 6.5 g of polymer per kg of dry matter, the required dosage for the thermophilic sludge was greater than 10 g/kg of dry matter. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  17. Production and characterization of granular activated carbon from activated sludge

    Directory of Open Access Journals (Sweden)

    Z. Al-Qodah

    2009-03-01

    Full Text Available In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m²/g. The FT-IR analysis depicts the presence of a variety of functional groups which explain its improved adsorption behavior against pesticides. The XRD analysis reveals that the produced activated carbon has low content of inorganic constituents compared with the precursor. The adsorption isotherm data were fitted to three adsorption isotherm models and found to closely fit the BET model with R² equal 0.948 at pH 3, indicating a multilayer of pesticide adsorption. The maximum loading capacity of the produced activated carbon was 110 mg pesticides/g adsorbent and was obtained at this pH value. This maximum loading was found experimentally to steeply decrease as the solution pH increases. The obtained results show that activated sludge is a promising low cost precursor for the production of activated carbon.

  18. Operation performance and granule characterization of upflow anaerobic sludge blanket (UASB) reactor treating wastewater with starch as the sole carbon source.

    Science.gov (United States)

    Lu, Xueqin; Zhen, Guangyin; Estrada, Adriana Ledezma; Chen, Mo; Ni, Jialing; Hojo, Toshimasa; Kubota, Kengo; Li, Yu-You

    2015-03-01

    Long-term performance of a lab-scale UASB reactor treating starch wastewater was investigated under different hydraulic retention times (HRT). Successful start-up could be achieved after 15days' operation. The optimal HRT was 6h with organic loading rate (OLR) 4g COD/Ld at COD concentration 1000mg/L, attaining 81.1-98.7% total COD removal with methane production rate of 0.33L CH4/g CODremoved. Specific methane activity tests demonstrated that methane formation via H2-CO2 and acetate were the principal degradation pathways. Vertical characterizations revealed that main reactions including starch hydrolysis, acidification and methanogenesis occurred at the lower part of reactor ("main reaction zone"); comparatively, at the up converting acetate into methane predominated ("substrate-shortage zone"). Further reducing HRT to 3h caused volatile fatty acids accumulation, sludge floating and performance deterioration. Sludge floating was ascribed to the excess polysaccharides in extracellular polymeric substances (EPS). More efforts are required to overcome sludge floating-related issues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Biosorption of Cd, Cr, Mn, and Pb from aqueous solutions by Bacillus sp strains isolated from industrial waste activate sludge

    OpenAIRE

    García, Rocío; Campos, Juan; Cruz, Julio Alfonso; Calderón, Ma. Elena; Raynal, Ma. Elena; Buitrón, Germán

    2016-01-01

    Abstract The microorganisms are capable of accumulating heavy metal ions from water as biosorbent agents, offering a potential alternative for the detoxification and recovery of toxic/precious metals in industrial wastewater. In the present work, metal-resistant bacterial strains were isolated and identified from activated sludge of a waste treatment plant in the Municipality of Santa Rosa Jauregui, Querétaro. To obtain bacteria tolerant to metals, 37 bacterial strains and two isolates were s...

  20. Response of bacteria in wastewater sludge to moisture loss by evaporation and effect of moisture content on bacterial inactivation by ionizing radiation

    International Nuclear Information System (INIS)

    Ward, R.L.; Yeager, J.G.; Ashley, C.S.

    1981-01-01

    Two studies were carried out to determine the influence of moisture content on the survival of bacteria in raw wastewater sludge. The first study involved the effect of water loss by evaporation on the bacterial population. The second used these dewatered samples to measure the effects of moisture content on the inactivation of bacteria in sludge by ionizing radiation. Both studies involved survival measurements of six representative fecally associated bacteria grown separately in sterilized sludge as well as survival data on bacteria indigenous to sludge. Growth of bacteria was stimulated in sludge during the initial phase of moisture removal by evaporation, but the reduction of moisture content below about 50% by weight caused a proportional decrease in bacterial numbers. The rates of inactivation of bacteria by ionizing radiation in sludge were usually modified to some degree by variations in moisture content. Most bacteria were found to be somewhat protected from ionizing radiation at reduced moisture levels

  1. Modified anaerobic digestion elutriated phased treatment for the anaerobic co-digestion of sewage sludge and food wastewater.

    Science.gov (United States)

    Mo, Kyung; Lee, Wonbae; Kim, Moonil

    2017-02-01

    A modified anaerobic digestion elutriated phased treatment (MADEPT) process was developed for investigating anaerobic co-digestion of sewage sludge and food wastewater. The anaerobic digestion elutriated phased treatment (ADEPT) process is similar to a two-phase system, however, in which the effluent from a methanogenic reactor recycles into an acidogenic reactor to elutriate mainly dissolved organics. Although ADEPT could reduce reactor volume significantly, the unsolubilized solids should be wasted from the system. The MADEPT process combines thermo-alkali solubilization with ADEPT to improve anaerobic performance and to minimize the sludge disposal. It was determined that the optimal volume mixing ratio of sewage sludge and food wastewater was 4 : 1 for the anaerobic co-digestion. The removal efficiencies of total chemical oxygen demand, volatile solids, and volatile suspended solids in the MADEPT process were 73%, 70%, and 64%, respectively. However, those in the ADEPT process were only 48%, 37%, and 40%, respectively, at the same hydraulic retention time (HRT) of 7 days. The gas production of MADEPT was two times higher than that of ADEPT. The thermo-alkali solubilization increased the concentration of dissolved organics so that they could be effectively degraded in a short HRT, implying that MADEPT could improve the performance of ADEPT in anaerobic co-digestion.

  2. Acid Fermentation Process Combined with Post Denitrification for the Treatment of Primary Sludge and Wastewater with High Strength Nitrate

    Directory of Open Access Journals (Sweden)

    Allen Kurniawan

    2016-03-01

    Full Text Available In this study, an anaerobic baffled reactor (ABR, combined with a post denitrification process, was applied to treat primary sludge from a municipal wastewater treatment plant and wastewater with a high concentration of nitrate. The production of volatile fatty acids (VFAs was maximized with a short hydraulic retention time in the acid fermentation of the ABR process, and then the produced VFAs were supplied as an external carbon source for the post denitrification process. The laboratory scale experiment was operated for 160 days to evaluate the VFAs’ production rate, sludge reduction in the ABR type-acid fermentation process, and the specific denitrification rate of the post denitrification process. As results, the overall removal rate of total chemical oxygen demand (TCOD, total suspended solids (TSS, and total nitrogen (TN were found to be 97%, 92%, 73%, respectively, when considering the influent into ABR type-acid fermentation and effluent from post denitrification. We observed the specific VFAs production rate of 0.074 gVFAs/gVSS/day for the ABR type-acid fermentation, and an average specific denitrification rate of 0.166 gNO3−-N/gVSS/day for the post denitrification. Consequently, we observed that a high production of VFAs from a primary sludge, using application of the ABR type acid fermentation process and the produced VFAs were then successfully utilized as an external carbon source for the post denitrification process, with a high removal rate of nitrogen.

  3. 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.

  4. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    NARCIS (Netherlands)

    Leitao, R.; Santaellla, S.T.; Haandel, van A.C.; Zeeman, G.; Lettinga, G.

    2009-01-01

    The effects of hydraulic retention time (HRT) and influent COD concentration (CODInf) on Specific Methanogenic Activity (SMA) and the biodegradability of an anaerobic sludge need to be elucidated because of the discordant results available in literature. This information is important for the

  5. Degradation of typical N-nitrosodimethylamine (NDMA) precursors and its formation potential in anoxic-aerobic (AO) activated sludge system.

    Science.gov (United States)

    Wang, Lin; Li, Yongmei; He, Guodong

    2014-01-01

    N-nitrosodimethylamine (NDMA) is an emerging disinfection byproduct. Removal of its potential precursors is considered as an effective method to control NDMA. In this study, four typical NDMA precursors (dimethylamine (DMA), trimethylamine (TMA), dimethylformamide (DMFA) and dimethylaminobenzene (DMAB)) were selected, and their removal capacities by activated sludge were investigated. Batch experiments indicated that removal of NDMA precursors was better under aerobic condition than anoxic condition; and their specific degradation rates follow the order of DMA > TMA > DMFA > DMAB. In anoxic-aerobic (AO) activated sludge system, the optimal hydraulic retention time and sludge retention time were 10 h and 20 d, respectively, for the removal of both NDMA precursors (four selected NDMA precursors and NDMA formation potential (NDMA FP)) and nutrients. Our results also suggested that there was a positive correlation between NDMA FP and dissolved organic nitrogen (DON) in wastewater. The removal efficiency of NDMA FP was in the range of 46.8-72.5% in the four surveyed wastewater treatment plants except the one which adopted chemically enhanced primary process. The results revealed that the AO system had the advantage of removing NDMA FP. Our results are helpful for the knowledge of the removals of NDMA precursors during activated sludge treatment processes.

  6. The effect of activated carbon addition on membrane bioreactor processes for wastewater treatment and reclamation - A critical review.

    Science.gov (United States)

    Skouteris, George; Saroj, Devendra; Melidis, Paraschos; Hai, Faisal I; Ouki, Sabèha

    2015-06-01

    This review concentrates on the effect of activated carbon (AC) addition to membrane bioreactors (MBRs) treating wastewaters. Use of AC-assisted MBRs combines adsorption, biodegradation and membrane filtration. This can lead to advanced removal of recalcitrant pollutants and mitigation of membrane fouling. The relative contribution of adsorption and biodegradation to overall removal achieved by an AC-assisted MBR process can vary, and "biological AC" may not fully develop due to competition of target pollutants with bulk organics in wastewater. Thus periodic replenishment of spent AC is necessary. Sludge retention time (SRT) governs the frequency of spent AC withdrawal and addition of fresh AC, and is an important parameter that significantly influences the performance of AC-assisted MBRs. Of utmost importance is AC dosage because AC overdose may aggravate membrane fouling, increase sludge viscosity, impair mass transfer and reduce sludge dewaterability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Toxicity evaluation and prediction of toxic chemicals on activated sludge system.

    Science.gov (United States)

    Cai, Bijing; Xie, Li; Yang, Dianhai; Arcangeli, Jean-Pierre

    2010-05-15

    The gaps of data for evaluating toxicity of new or overloaded organic chemicals on activated sludge system resulted in the requirements for methodology of toxicity estimation. In this study, 24 aromatic chemicals typically existed in the industrial wastewater were selected and classified into three groups of benzenes, phenols and anilines. Their toxicity on activated sludge was then investigated. Two indexes of IC(50-M) and IC(50-S) were determined respectively from the respiration rates of activated sludge with different toxicant concentration at mid-term (24h) and short-term (30min) time intervals. Experimental results showed that the group of benzenes was the most toxic, followed by the groups of phenols and anilines. The values of IC(50-M) of the tested chemicals were higher than those of IC(50-S). In addition, quantitative structure-activity relationships (QSARs) models developed from IC(50-M) were more stable and accurate than those of IC(50-S). The multiple linear models based on molecular descriptors and K(ow) presented better reliability than single linear models based on K(ow). Among these molecular descriptors, E(lumo) was the most important impact factor for evaluation of mid-term toxicity. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  8. Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass

    DEFF Research Database (Denmark)

    Domingo-Felez, Carlos; Smets, Barth F.

    A pseudo-mechanistic model describing three biological nitric oxide (NO) and nitrous oxide (N2O) production pathways was calibrated for an activated sludge mixed culture biomass treating municipal wastewater with laboratory-scale experiments. The model (NDHA) comprehensively describes N2O produci...

  9. Energy and nutrient recovery for munipal wastewater treatment : how to design a feasible plant layout?

    NARCIS (Netherlands)

    Khiewwijit, R.; Temmink, B.G.; Rijnaarts, H.H.M.; Keesman, K.J.

    2016-01-01

    Activated sludge systems are commonly used for robust and efficient treatment of municipal wastewater. However, these systems cannot achieve their maximum potential to recover valuable resources from wastewater. This study demonstrates a procedure to design a feasible novel configuration for

  10. Factors influencing suspended solids concentrations in activated sludge settling tanks.

    Science.gov (United States)

    Kim, Y; Pipes, W O

    1999-05-31

    A significant fraction of the total mass of sludge in an activated sludge process may be in the settling tanks if the sludge has a high sludge volume index (SVI) or when a hydraulic overload occurs during a rainstorm. Under those conditions, an accurate estimate of the amount of sludge in the settling tanks is needed in order to calculate the mean cell residence time or to determine the capacity of the settling tanks to store sludge. Determination of the amount of sludge in the settling tanks requires estimation of the average concentration of suspended solids in the layer of sludge (XSB) in the bottom of the settling tanks. A widely used reference recommends averaging the concentrations of suspended solids in the mixed liquor (X) and in the underflow (Xu) from the settling tanks (XSB=0. 5{X+Xu}). This method does not take into consideration other pertinent information available to an operator. This is a report of a field study which had the objective of developing a more accurate method for estimation of the XSB in the bottom of the settling tanks. By correlation analysis, it was found that only 44% of the variation in the measured XSB is related to sum of X and Xu. XSB is also influenced by the SVI, the zone settling velocity at X and the overflow and underflow rates of the settling tanks. The method of averaging X and Xu tends to overestimate the XSB. A new empirical estimation technique for XSB was developed. The estimation technique uses dimensionless ratios; i.e., the ratio of XSB to Xu, the ratio of the overflow rate to the sum of the underflow rate and the initial settling velocity of the mixed liquor and sludge compaction expressed as a ratio (dimensionless SVI). The empirical model is compared with the method of averaging X and Xu for the entire range of sludge depths in the settling tanks and for SVI values between 100 and 300 ml/g. Since the empirical model uses dimensionless ratios, the regression parameters are also dimensionless and the model can be

  11. Screening the possibility for removing cadmium and other heavy metals from wastewater sludge and bio-ashes by an electrodialytic method

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul; Hansen, Henrik K.

    2007-01-01

    in wastewater sludge and bio-ashes (straw and wood) using an electrodialytic method. The waste products were treated as stirred suspensions. During the remediation the suspension was acidified from water splitting at the anion exchange membrane and the acidification mobilized Cd that was removed...... with Cd, and the wood ash had a high initial pH (13.3). The mass of wastewater sludge and bio-ashes decreased during treatment but the concentration of other heavy metals (Pb, Ni, Cu and Zn) was not increased to exceed limiting values in remediated matrix.......Both wastewater sludge and fly ash from combustion of biomass (bio-ash) have traditionally been applied to agricultural land in Denmark. However, Cd concentrations often exceed limiting values. The present study is a preliminary investigation of the possibility for reducing the Cd concentration...

  12. 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

    2001-01-01

    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......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 characterise the changes in floc properties that led to settling and dewatering problems and to find reasons for this taking place, a comprehensive monitoring program was conducted during more than one year. The monitoring program included various measurements of floc settleability, floc strength and sludge...

  13. A critical comparison of systematic calibration protocols for activated sludge models: a SWOT analysis.

    Science.gov (United States)

    Sin, Gürkan; Van Hulle, Stijn W H; De Pauw, Dirk J W; van Griensven, Ann; Vanrolleghem, Peter A

    2005-07-01

    Modelling activated sludge systems has gained an increasing momentum after the introduction of activated sludge models (ASMs) in 1987. Application of dynamic models for full-scale systems requires essentially a calibration of the chosen ASM to the case under study. Numerous full-scale model applications have been performed so far which were mostly based on ad hoc approaches and expert knowledge. Further, each modelling study has followed a different calibration approach: e.g. different influent wastewater characterization methods, different kinetic parameter estimation methods, different selection of parameters to be calibrated, different priorities within the calibration steps, etc. In short, there was no standard approach in performing the calibration study, which makes it difficult, if not impossible, to (1) compare different calibrations of ASMs with each other and (2) perform internal quality checks for each calibration study. To address these concerns, systematic calibration protocols have recently been proposed to bring guidance to the modeling of activated sludge systems and in particular to the calibration of full-scale models. In this contribution four existing calibration approaches (BIOMATH, HSG, STOWA and WERF) will be critically discussed using a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis. It will also be assessed in what way these approaches can be further developed in view of further improving the quality of ASM calibration. In this respect, the potential of automating some steps of the calibration procedure by use of mathematical algorithms is highlighted.

  14. Fate of sulfonamide antibiotics in contact with activated sludge--sorption and biodegradation.

    Science.gov (United States)

    Yang, Sheng-Fu; Lin, Cheng-Fang; Wu, Chien-Ju; Ng, Kok-Kwang; Lin, Angela Yu-Chen; Hong, Pui-Kwan Andy

    2012-03-15

    The sorption and biodegradation of three sulfonamide antibiotics, namely sulfamethoxazole (SMX), sulfadimethoxine (SDM), and sulfamonomethoxine (SMM), in an activated sludge system were investigated. Experiments were carried out by contacting 100 μg/L of each sulfonamide compound individually with 2.56 g/L of MLSS at 25±0.5 °C, pH 7.0, and dissolved oxygen of 3.0±0.1 mg/L in a batch reactor over different periods of 2 d and 14 d. All sulfonamides were removed completely over 11-13 d. Sorptive equilibrium was established well within the first few hours, followed by a lag period of 1-3 days before biodegradation was to deplete the antibiotic compounds linearly in the ensuing 10 days. Apparent zeroth-order rate constants were obtained by regression analysis of measured aqueous concentration vs. time profiles to a kinetic model accounting for sorption and biodegradation; they were 8.1, 7.9, and 7.7 μg/L/d for SDM, SMX, and SMM, respectively, at activated sludge concentration of 2.56 g/L. The measured kinetics implied that with typical hydraulic retention time (e.g. 6 h) provided by WWTP the removal of sulfonamide compounds from the wastewater during the activated sludge process would approximate 2 μg/L. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Response of bacteria in wastewater sludge to moisture loss by evaporation and effect of moisture content on bacterial inactivation by ionizing radiation.

    OpenAIRE

    Ward, R L; Yeager, J G; Ashley, C S

    1981-01-01

    Two studies were carried out to determine the influence of moisture content of the survival of bacteria in raw wastewater sludge. The first study involved the effect of water loss by evaporation on the bacterial population. The second used these dewatered samples to measure the effects of moisture content on the inactivation of bacteria sludge by ionizing radiation. Both studies involved survival measurements of six representative fecally associated bacteria grown separately in sterilized slu...

  16. Solidified structure and leaching properties of metallurgical wastewater treatment sludge after solidification/stabilization process.

    Science.gov (United States)

    Radovanović, Dragana Đ; Kamberović, Željko J; Korać, Marija S; Rogan, Jelena R

    2016-01-01

    The presented study investigates solidification/stabilization process of hazardous heavy metals/arsenic sludge, generated after the treatment of the wastewater from a primary copper smelter. Fly ash and fly ash with addition of hydrated lime and Portland composite cement were studied as potential binders. The effectiveness of the process was evaluated by unconfined compressive strength (UCS) testing, leaching tests (EN 12457-4 and TCLP) and acid neutralization capacity (ANC) test. It was found that introduction of cement into the systems increased the UCS, led to reduced leaching of Cu, Ni and Zn, but had a negative effect on the ANC. Gradual addition of lime resulted in decreased UCS, significant reduction of metals leaching and high ANC, due to the excess of lime that remained unreacted in pozzolanic reaction. Stabilization of more than 99% of heavy metals and 90% of arsenic has been achieved. All the samples had UCS above required value for safe disposal. In addition to standard leaching tests, solidificates were exposed to atmospheric conditions during one year in order to determine the actual leaching level of metals in real environment. It can be concluded that the EN 12457-4 test is more similar to the real environmental conditions, while the TCLP test highly exaggerates the leaching of metals. The paper also presents results of differential acid neutralization (d-AN) analysis compared with mineralogical study done by scanning electron microscopy and X-ray diffraction analysis. The d-AN coupled with Eh-pH (Pourbaix) diagrams were proven to be a new effective method for analysis of amorphous solidified structure.

  17. Screening the possibility for removing cadmium and other heavy metals from wastewater sludge and bio-ashes by an electrodialytic method

    International Nuclear Information System (INIS)

    Ottosen, Lisbeth M.; Pedersen, Anne J.; Hansen, Henrik K.; Ribeiro, Alexandra B.

    2007-01-01

    Both wastewater sludge and fly ash from combustion of biomass (bio-ash) have traditionally been applied to agricultural land in Denmark. However, Cd concentrations often exceed limiting values. The present study is a preliminary investigation of the possibility for reducing the Cd concentration in wastewater sludge and bio-ashes (straw and wood) using an electrodialytic method. The waste products were treated as stirred suspensions. During the remediation the suspension was acidified from water splitting at the anion exchange membrane and the acidification mobilized Cd that was removed to the electrode compartments. Even though the matrices were very different the remediation was successful in all cases. After treatment the Cd concentration in the ashes allowed for spreading at agricultural land and the limiting concentration of 0.8 mg Cd/kg for the wastewater sludge was almost reached (0.84 and 0.88 mg Cd/kg). The main differences of the waste products influencing the remediation process were: the sludges had a high content of organic particles that were mobilized by electrophoresis and fouled the anion exchange membrane; the straw-ash contained a lot of chloride, which formed anionic complexes with Cd, and the wood ash had a high initial pH (13.3). The mass of wastewater sludge and bio-ashes decreased during treatment but the concentration of other heavy metals (Pb, Ni, Cu and Zn) was not increased to exceed limiting values in remediated matrix

  18. ASSESSMENT OF THE POSSIBILITIES OF AGRICULTURAL USE OF SEWAGE SLUDGE FROM WASTEWATER TREATMENT PLANTS IN OLECKO

    Directory of Open Access Journals (Sweden)

    Magdalena Filkiewicz

    2015-03-01

    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.

  19. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-01-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge. PMID:27905538

  20. Optimization and control of the activated sludge process by adaptation of aeration tank volume

    Energy Technology Data Exchange (ETDEWEB)

    Staud, R

    1982-04-01

    Purpose of full scale studies conducted at a municipal wastewater treatment plant at Schwetzingen, Germany, was to optimize the activated sludge treatment process. Influent loading fluctuations were answered by operating a distinct number of the four parallel treatment plant units (aeration tank/clarifier) present. During the intermediate period of time the aerators were also switched off, and the activated sludge was kept anaerobically. The purpose of this particular technique is to equalize the nutrient supply of the microorganisms to gain an improved metabolic potential, as well as to decrease the energy demand for aeration. A mathematical algorithm for process control was developed to accomplish this technique. Initial parameters are inflow rate, MLSS and plateau-BOD to evaluate the substrate concentration. The results of the full scale studies prove the practicability of this concept. Equalization of the F:M ratio fluctuations leads to an increase of the average substrate loading but not to any decrease in the overall process efficiency. Anaerobic sludge storage did not cause any problem. Odor problems could be handled by limitation of the storage period to 24 hours. As far as energy consumption for aeration is concerned a decrease by 47% percent could be achieved.

  1. ACTIVATED SLUDGE PROCESS SIMULATOR ASP-SIM, PART-1 ...

    African Journals Online (AJOL)

    LUCY

    The design of activated process is usually done manually; this is often difficult and susceptible to errors ... Table 1: Typical domestic wastewater characterization parameters for CMAS design. ..... g = 9.81: molarmass = 28.97: zb = 500: za = 0: r.

  2. The compost with the OFMSW as a solution for the sludges from the wastewater purification plants; Compostaje con FORSU como una solucion para los fangos de depuradora

    Energy Technology Data Exchange (ETDEWEB)

    Chica Perez, A.; Diaz Rubio, M. M.; Mohedo Gaton, J. J.; Martin Martin, A. [Universidad de Cardoba (Spain); Revilla Alvarez, J. R.

    2001-07-01

    The correct management of the sludges coming from the municipal wastewater purification plants (mwpp) is an unsolved problem in many cases and its volume is quickly increasing. As a solution for its treatment and disposal the composting process of the sludges combined with the organic fraction of municipal solid wastes (OFMSW) selectively collected is proposed in this work. A suitable compost for agricultural use is obtained. Using respirometer methods better than using other analytical parameters can monitor the stabilisation process of the mixture of sludges from MWPP and OFMSW. The measurement of the maximum oxygen intake specific rate indicates an appropriate stabilisation of the mixture after third treatment month. (Author) 32 refs.

  3. 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)

    2016-09-01

    A preliminary process model and techno-economic analysis (TEA) was completed for fuel produced from hydrothermal liquefaction (HTL) of sludge waste from a municipal wastewater treatment plant (WWTP) and subsequent biocrude upgrading. The model is adapted from previous work by Jones et al. (2014) for algae HTL, using experimental data generated in fiscal year 2015 (FY15) bench-scale HTL testing of sludge waste streams. Testing was performed on sludge samples received from Metro Vancouver’s Annacis Island WWTP (Vancouver, B.C.) as part of a collaborative project with the Water Environment and Reuse Foundation (WERF). The full set of sludge HTL testing data from this effort will be documented in a separate report to be issued by WERF. This analysis is based on limited testing data and therefore should be considered preliminary. In addition, the testing was conducted with the goal of successful operation, and therefore does not represent an optimized process. Future refinements are necessary to improve the robustness of the model, including a cross-check of modeled biocrude components with the experimental GCMS data and investigation of equipment costs most appropriate at the relatively small scales used here. Environmental sustainability metrics analysis is also needed to understand the broader impact of this technology pathway. The base case scenario for the analysis consists of 10 HTL plants, each processing 100 dry U.S. ton/day (92.4 ton/day on a dry, ash-free basis) of sludge waste and producing 234 barrel per stream day (BPSD) biocrude, feeding into a centralized biocrude upgrading facility that produces 2,020 barrel per standard day of final fuel. This scale was chosen based upon initial wastewater treatment plant data collected by PNNL’s resource assessment team from the EPA’s Clean Watersheds Needs Survey database (EPA 2015a) and a rough estimate of what the potential sludge availability might be within a 100-mile radius. In addition, we received

  4. Microscopic Analysis of Activated Sludge. Training Manual.

    Science.gov (United States)

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

    This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

  5. Enhanced treatment of waste frying oil in an activated sludge system by addition of crude rhamnolipid solution.

    Science.gov (United States)

    Zhang, Hongzi; Xiang, Hai; Zhang, Guoliang; Cao, Xia; Meng, Qing

    2009-08-15

    The presence of high-strength oil and grease (O&G) in wastewater poses serious challenges for environment. Addition of surfactant into the activated sludge bioreactor is feasible in reducing high concentrations of O&G via enhancing its bioavailability. In this paper, an aqueous biosurfactant solution of rhamnolipid as a cell-free culture broth of Pseudomonas aeruginosa zju.um1 was added into a batch of aerobic activated sludge system for treatment of the waste frying oil. This treatment was conducted on both bench and pilot-scales, whereas the removal efficiency of frying oil was determined by analyzing the residue concentration of O&G and chemical oxygen demand (COD). In the presence of varying concentrations of rhamnolipid from 22.5 mg/L to 90 mg/L, aerobic treatment for 30 h was enough to remove over 93% of O&G while this biodegradability was only 10% in the control system with the absence of rhamnolipids. The equivalent biodegradability was similarly obtained on COD under addition of rhamnolipid. Compared with bench studies, a higher treatment efficiency with the presence of rhamnolipids was achieved on a pilot-scale of activated sludge system, in which a short time of 12h was required for removing approximately 95% of O&G while the control treatment attained a low efficiency of 17%. Finally, foaming and biodegradability of rhamnolipids in activated sludge system were further examined in the whole treatment process. It seems that the addition of rhamnolipid-containing culture broth showed great potential for treatment of oily wastewater by activated sludge.

  6. Enhanced treatment of waste frying oil in an activated sludge system by addition of crude rhamnolipid solution

    International Nuclear Information System (INIS)

    Zhang Hongzi; Xiang Hai; Zhang Guoliang; Cao Xia; Meng Qing

    2009-01-01

    The presence of high-strength oil and grease (O and G) in wastewater poses serious challenges for environment. Addition of surfactant into the activated sludge bioreactor is feasible in reducing high concentrations of O and G via enhancing its bioavailability. In this paper, an aqueous biosurfactant solution of rhamnolipid as a cell-free culture broth of Pseudomonas aeruginosa zju.um1 was added into a batch of aerobic activated sludge system for treatment of the waste frying oil. This treatment was conducted on both bench and pilot-scales, whereas the removal efficiency of frying oil was determined by analyzing the residue concentration of O and G and chemical oxygen demand (COD). In the presence of varying concentrations of rhamnolipid from 22.5 mg/L to 90 mg/L, aerobic treatment for 30 h was enough to remove over 93% of O and G while this biodegradability was only 10% in the control system with the absence of rhamnolipids. The equivalent biodegradability was similarly obtained on COD under addition of rhamnolipid. Compared with bench studies, a higher treatment efficiency with the presence of rhamnolipids was achieved on a pilot-scale of activated sludge system, in which a short time of 12 h was required for removing approximately 95% of O and G while the control treatment attained a low efficiency of 17%. Finally, foaming and biodegradability of rhamnolipids in activated sludge system were further examined in the whole treatment process. It seems that the addition of rhamnolipid-containing culture broth showed great potential for treatment of oily wastewater by activated sludge.

  7. Ammonia-oxidizing bacteria and archaea in wastewater treatment plant sludge and nearby coastal sediment in an industrial area in China.

    Science.gov (United States)

    Zhang, Yan; Chen, Lujun; Sun, Renhua; Dai, Tianjiao; Tian, Jinping; Wen, Donghui

    2015-05-01

    Under the increasing pressure of human activities, Hangzhou Bay has become one of the most seriously polluted waters along China's coast. Considering the excessive inorganic nitrogen detected in the bay, in this study, the impact of an effluent from a coastal industrial park on ammonia-oxidizing microorganisms (AOMs) of the receiving area was interpreted for the first time by molecular technologies. Revealed by real-time PCR, the ratio of archaeal amoA/bacterial amoA ranged from 5.68 × 10(-6) to 4.79 × 10(-5) in the activated sludge from two wastewater treatment plants (WWTPs) and 0.54-3.44 in the sediments from the effluent receiving coastal area. Analyzed by clone and pyrosequencing libraries, genus Nitrosomonas was the predominant ammonia-oxidizing bacteria (AOB), but no ammonia-oxidizing archaea (AOA) was abundant enough for sequencing in the activated sludge from the WWTPs; genus Nitrosomonas and Nitrosopumilus were the dominant AOB and AOA, respectively, in the coastal sediments. The different abundance of AOA but similar structure of AOB between the WWTPs and nearby coastal area probably indicated an anthropogenic impact on the microbial ecology in Hangzhou Bay.

  8. Adsorption of Heavy Metals on Biologically Activated Brown Coal Sludge

    Directory of Open Access Journals (Sweden)

    Mária Praščáková

    2005-11-01

    Full Text Available Adsorption of cooper (II and zinc (II ions from aqueous solutions on a biologically activated brown coal sludge was investigated. Four families of adsorbents were prepared from the brown coal sludge bya microorganism’s activity. There were used microscopic fungi such as Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride. Prepared sorbents were capable of removing Cu (II and Zn (II. The sorption isotherm has been constructed and the specific metal uptake and the maximum capacity of the adsorbent have been determined.

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

    Science.gov (United States)

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

    2010-01-01

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

  10. Research Advance on Polybrominated Diphenyl Ethers in Wastewater and Sewage Sludge%污水及污泥中多溴联苯醚的研究进展

    Institute of Scientific and Technical Information of China (English)

    孟祥周; 杨超; 潘兆宇; 陈玲

    2011-01-01

    多溴联苯醚是一类溴代阻燃剂,包括三种主要的工业产品,五溴、八溴、十溴联苯醚.该物质曾广泛使用于电子、材料、家具等产品中.研究表明,在这些产品的生产、使用和处理过程中均会释放多溴联苯醚到周边环境中.多溴联苯醚具有持久性、可生物富集和长距离迁移,对人体和身体系统存在潜在危害,是一类新兴污染物.目前,这类物质中的部分化合物已被禁止生产和使用.一方而,人类曾使用的多溴联苯醚会通过工业废水和生活污水的排放汇集于污水和污泥,继而又成为环境介质中多溴联苯醚的重要来源.文章系统综述了国内外污水和污泥中多溴联苯醚的污染浓度水平、同系物分布特征和环境效应,为进一步开发污水处理中多溴联苯醚的去除技术和制定污水和污泥中多溴联苯醚的控制标准奠定了基础.%Polybrominated diphenyl ethers (PBDEs) are one group of flame retardants, including 3 major commercial products such as penta-, octa-and deca-BDE. PBDEs were widely used in electrical, material and furniture products. The previous studies showed that PBDEs can be released to the surroundings during the production, usage and disposal process of the products containing PBDEs. As emerging pollutants, PBDEs which are relatively persistent with potential for long range transport and bioaccumulation in biota have potential toxicity to ecosystem and human beings, thus some compounds of PBDEs were banned by the Stockholm Convention. PBDEs discharged by human activity before can gather in wastewater and sewage sludge, and then entered into environmental media by disposal of wastewater and sewage sludge. The concentrations, distribution and environmental effects of PBDEs were reviewed in order to provide the basis for developing treatment technology and making control standards for PBDEs in wastewater and sewage 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.

    2015-01-01

    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. Codigestion of olive oil mill wastewaters with manure, household waste or sewage sludge

    DEFF Research Database (Denmark)

    Angelidaki, I.; Ahring, B.K.

    1997-01-01

    Combined anaerobic digestion of oil mill effluent (OME) together with manure, household waste (HHW) or sewage sludge was investigated. In batch experiments it was shown that OME could be degraded into biogas when codigested with manure. In codigestion with HHW or sewage sludge, OME dilution...

  13. Effects of moisture content on long-term survival and regrowth of bacteria in wastewater sludge

    Energy Technology Data Exchange (ETDEWEB)

    Yeager, J.G. (BDM Corp., Albuquerque, NM); Ward, R.L.

    1981-05-01

    The effects of moisture content on the survival and regrowth of seeded and indigenous enteric bacteria in raw sludge were determined. Cultures of six strains of fecally associated bacteria grown in sterilized, liquid sludge (5% solids) were all quite stable at this moisture level for over 90 days at 21/sup 0/C. When the moisture content of the sludge containing these organisms was reduced by evaporation and the samples were stored at 21/sup 0/C for extended periods, bacterial inactivation rates were generally proportional to the moisture losses of the samples. A dramatic reversal in this effect was observed in samples containing more than 90% solids. In this dried sludge, every bacterial species studied except Proteus mirabilis was found to be extremely stable. Bacteria indigenous to sludge were also found to survive for long periods in dried sludge. Growth of seeded Salmonella typhimurium was also found to occur in the presence of indigenous organisms in both liquid and dewatered raw sludges. However, the population density attained was well below that found in sterilized samples of the same sludges.

  14. Specific methanogenic activity (SMA of industrial sludge from the aerobic and anaerobic biological treatment

    Directory of Open Access Journals (Sweden)

    Danieli Schneiders

    2013-08-01

    Full Text Available In this study, specific methanogenic activity (SMA tests were performed on textile sludge and food industry sludge. The textile sludge from an activated sludge was collected at the entrance of the secondary biologic clarifier and the food sludge was collected in a UASB reactor. Once collected, the sludges were characterized and tested for SMA. It was found that the microrganisms present in the food sludge had SMA of 0.17 gCOD-CH4 gSSV.d-1 and 337.05 mL of methane production, while the microrganisms of the textile sludge presented 0.10 gCOD-CH4 gSSV.d-1 of SMA and 3.04 mL of methane production. Therefore, the food sludge was more suitable to be used as a starting inoculum in UASB.

  15. Assessment of nutritional value of single-cell protein from waste-activated sludge as a protein supplement in poultry feed.

    Science.gov (United States)

    Nkhalambayausi-Chirwa, Evans M; Lebitso, Moses T

    2012-12-01

    The amount of protein wasted through sludge in Gauteng, South Africa, amounts to 95 000 metric tonne/yr, with the order of magnitude of the national protein requirement of approximately 145 000 metric tonne/yr. Waste-activated sludge (WAS) from wastewater treatment plants (WWTPs) that treat domestic wastewater contains protein in a ratio of 2:1 against fishmeal. This protein source has not been utilized because of the high content of toxic heavy metals and other potential carcinogenic pollutants in the sludge. In this study, a pretreatment method of modified aqua regia dilute acid wash was used to lower the metal content by approximately 60%. However, this resulted in a 33% loss of amino acids in the acid-washed WAS. A feed substitution test in poultry with different fishmeal-sludge ratios (0%, 25%, 50%, 75%, and 100% WAS as percent substitution of fishmeal) showed no impact of sludge single-cell protein (SCP) on mortality rate. However, sludge substitution in the feed yielded weight gains and cost savings up to 46%.

  16. Sensitivity study of reduced models of the activated sludge process ...

    African Journals Online (AJOL)

    2009-08-07

    Aug 7, 2009 ... Sensitivity study of reduced models of the activated sludge process, for the purposes