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Sample records for anaerobic reactor systems

  1. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter;

    2003-01-01

    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  2. Biometanation of Distillery Wastewater in an Anaerobic Baffled Reactor System

    Directory of Open Access Journals (Sweden)

    Lalov I. G.

    2007-12-01

    Full Text Available Anaerobic digestion is an established technology for distillery effluent treatment witch seems to be a promising alternative for Bulgarian industry. In this study the methanogenic activity of two different naturally formed microbial consortiums was compared. The better one was used to start continuous anaerobic digestion of high-strength distillery wastewater (COD 85 520 mgO2 . l-1 in laboratory scale anaerobic baffled reactor system. The average applied organic loading rate and hydraulic retention time were 4.28 kg COD m-3 . d-1 and 20 d respectively. A COD reduction of about 98 % and specific methane production of 0.39 m3 . kg-1 CODremoved were reached. Effects of different inhibitory factors such as low pH and presence of oxygen were investigated. In spite of unfavorable factors were applied simultaneously after an adaptation period the reactor showed stable response. The results obtained show the feasibility of this anaerobic process for distillery effluent treatment, representing a valid option to up-grade the existing wastewater treatment processes.

  3. A bio-electrochemical system for removing inhibitors of anaerobic digestion processes from anaerobic reactors

    DEFF Research Database (Denmark)

    2014-01-01

    Inhibition of anaerobic digestion process by high level of ammonia (NH4 +/I\\IH3) is the most serious problem existing in biogas plants. No viable/applicable method to overcome this problem has been found up to now. This invention proposes an innovative submersible bio-electrochemical membrane...... reactor to recover ammonia from anaerobic digestion reactor, and thereby alleviate or counteract ammonia inhibition and enhance the conversion of ammonia-rich wastes to biogas. The invention may further reduce overall cost, giving synergistic advantages for both ammonia recycling and biogas plants...

  4. A new VFA sensor technique for anaerobic reactor systems

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    to its small size it can be placed in lab-scale reactors without disturbing the process. Using this filtration technique together with commercially available membrane filters we have constructed a VFA sensor system that can perform automatic analysis of animal slurry at a frequency as high as every 15...... to monitor VFA online in one of the most difficult media: animal slurry or manure. A novel in situ filtration technique has made it possible to perform microfiltration inside a reactor system. This filter enables sampling from closed reactor systems without large-scale pumping and filters. Furthermore, due...... filtration technique are being presented is this article....

  5. Advances in high rate anaerobic treatment: staging of reactor systems.

    NARCIS (Netherlands)

    Lier, van J.B.; Zee, van der F.P.; Tan, N.C.G.; Rebac, S.; Kleerebezem, R.

    2001-01-01

    Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide acceptan

  6. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  7. Relationships between chemical oxygen demand (COD) components and toxicity in a sequential anaerobic baffled reactor/aerobic completely stirred reactor system treating Kemicetine.

    Science.gov (United States)

    Sponza, Delia Teresa; Demirden, Pinar

    2010-04-15

    In this study the interactions between toxicity removals and Kemicetine, COD removals, intermediate products of Kemicetine and COD components (CODs originating from slowly degradable organics, readily degradable organics, inert microbial products and from the inert compounds) were investigated in a sequential anaerobic baffled reactor (ABR)/aerobic completely stirred tank reactor (CSTR) system with a real pharmaceutical wastewater. The total COD and Kemicetine removal efficiencies were 98% and 100%, respectively, in the sequential ABR/CSTR systems. 2-Amino-1 (p-nitrophenil)-1,3 propanediol, l-p-amino phenyl, p-amino phenol and phenol were detected in the ABR as the main readily degradable inter-metabolites. In the anaerobic ABR reactor, the Kemicetin was converted to corresponding inter-metabolites and a substantial part of the COD was removed. In the aerobic CSTR reactor the inter-metabolites produced in the anaerobic reactor were completely removed and the COD remaining from the anerobic reactor was biodegraded. It was found that the COD originating from the readily degradable organics did not limit the anaerobic degradation process, while the CODs originating from the slowly degradable organics and from the inert microbial products significantly decreased the anaerobic ABR reactor performance. The acute toxicity test results indicated that the toxicity decreased from the influent to the effluent of the aerobic CSTR reactor. The ANOVA test statistics showed that there was a strong linear correlation between acute toxicity, CODs originating from the slowly degradable organics and inert microbial products. A weak correlation between acute toxicity and CODs originating from the inert compounds was detected.

  8. Evaluation of anaerobic sludge volume for improving azo dye decolorization in a hybrid anaerobic reactor with built-in bioelectrochemical system.

    Science.gov (United States)

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Wang, Ai-Jie; Cheng, Hao-Yi

    2017-02-01

    A hybrid anaerobic reactor with built-in bioelectrochemical system (BES) has been verified for efficiently treating mixed azo dye wastewater, yet still facing many challenges, such as uncertain reactor construction and insufficient electron donors. In this study, an up-flow hybrid anaerobic reactor with built-in BES was developed for acid orange 7 (AO7) containing wastewater treatment. Cathode and real domestic wastewater both served as electron donor for driving azo dye decolorization. The decolorization efficiency (DE) of AO7 (200 mg/L) in the hybrid reactor was 80.34 ± 2.11% with volume ratio between anaerobic sludge and cathode (VRslu:cat) of 0.5:1 and hydraulic retention time (HRT) of 6 h, which was 15.79% higher than that in BES without sludge zone. DE was improved to 86.02 ± 1.49% with VRslu:cat increased to 1:1. Further increase in the VRslu:cat to 1.5:1 and 2:1, chemical oxygen demand (COD) removal efficiency was continuously improved to 28.78 ± 1.96 and 32.19 ± 0.62%, but there was no obvious DE elevation (slightly increased to 87.62 ± 2.50 and 90.13 ± 3.10%). BES presented efficient electron utilization, the electron usage ratios (EURs) in which fluctuated between 11.02 and 13.06 mol e(-)/mol AO7. It was less than half of that in sludge zone of 24.73-32.06 mol e(-)/mol AO7. The present work optimized the volume ratio between anaerobic sludge and cathode that would be meaningful for the practical application of this hybrid system.

  9. Conversion of Methanogenic Substrates in Anaerobic Reactors

    OpenAIRE

    Gonzalez-Gil, G.

    2000-01-01

    The EGSB systems represents an attractive option to extend further the use of anaerobic technology for wastewater treatment, particularly with respect to waste streams originating from chemical industries. Frequently chemical waste streams are unbalanced with respect to nutrients and/or micronutrients and furthermore these streams may contain toxic-biodegradable compounds. To reduce toxicity high recycle ratios may be applied as in the case of EGSB reactors however, this at the same time may ...

  10. Investigation of Anaerobic Fluidized Bed Reactor Aerobic Mov-ing Bed Bio Reactor (AFBR/MMBR System for Treatment of Currant Wastewater

    Directory of Open Access Journals (Sweden)

    Jalil Jafari

    2013-08-01

    Full Text Available Background: Anaerobic treatment methods are more suitable for the treatment of concentrated wastewater streams, offer lower operating costs, the production of usable biogas product. The aim of this study was to investigate the performance of an Anaerobic Fluidized Bed Reactor (AFBR-Aerobic Moving Bed Bio Reactor (MBBR in series arrangement to treat Currant wastewater.Methods: The bed materials of AFBR were cylindrical particles made of PVC with a diameter of 2-2.3 mm, particle density of 1250 kg/m3.The volume of all bed materials was 1.7 liter which expanded to 2.46 liters in fluidized situation. In MBBR, support media was composed of 1.5 liters Bee-Cell 2000 having porosity of 87% and specific surface area of 650m2/m3.Results: When system operated at 35 ºC, chemical oxygen demand (COD removal efficiencies were achieved to 98% and 81.6% for organic loading rates (OLR of 9.4 and 24.2 g COD/l.d, and hydraulic retention times (HRT of 48 and 18 h, in average COD concentration feeding of 18.4 g/l, respectively.Conclusion: The contribution of AFBR in total COD removal efficiency at an organic loading rate (OLR of 9.4 g COD/l.d was 95%, and gradually decreased to 76.5% in OLR of 24.2 g COD/l.d. Also with increasing in organic loading rate the contribution of aerobic reactor in removing COD gradually decreased. In this system, the anaerobic reactor played the most important role in the removal of COD, and the aerobic MBBR was actually needed to polish the anaerobic treated wastewate

  11. Effects of nitrobenzene concentration and hydraulic retention time on the treatment of nitrobenzene in sequential anaerobic baffled reactor (ABR)/continuously stirred tank reactor (CSTR) system.

    Science.gov (United States)

    Kuscu, Ozlem Selcuk; Sponza, Delia Teresa

    2009-04-01

    The effects of increasing nitrobenzene (NB) concentrations and hydraulic retention times (HRT) on the treatment of NB were investigated in a sequential anaerobic baffled reactor (ABR)/aerobic completely stirred tank reactor (CSTR) system. In the first step of the study, the maximum COD removal efficiencies were found as 88% and 92% at NB concentrations varying between 30 mg L(-1) and 210 mg L(-1) in ABR. The minimum COD removal efficiency was 79% at a NB concentration of 700 mg L(-1). The removal efficiency of NB was nearly 100% for all NB concentrations in the ABR reactor. The methane gas production and the methane gas percentage remained stable (1500 mL day(-1) and 48-50%, respectively) as the NB concentration was increased from 30 to 210 mg L(-1). In the second step of the study it was found that as the HRT decreased from 10.38 days to 2.5 days the COD removal efficiencies decreased slightly from 94% to 92% in the ABR. For maximum COD and NB removal efficiencies the optimum HRT was found as 2.5 days in the ABR. The total COD removal efficiency was 95% in sequential anaerobic (ABR)/aerobic (CSTR) reactor system at a minimum HRT of 1 day. When the HRT was decreased from 10.38 days to 1 day, the methane percentage decreased from 42% to 29% in an ABR reactor treating 100 mg L(-1) NB. Nitrobenzene was reduced to aniline under anaerobic conditions while aniline was mineralized to catechol with meta cleavage under aerobic conditions.

  12. Evaluation of marine algae as a source of biogas in a two-stage anaerobic reactor system

    Energy Technology Data Exchange (ETDEWEB)

    Vergara-Fernandez, Alberto; Vargas, Gisela [Escuela de Ingenieria Ambiental, Facultad de Ingenieria, Universidad Catolica de Temuco, Manuel Montt 56, Casilla 15-D, Temuco (Chile); Alarcon, Nelson [Departamento de Ingenieria Quimica, Facultad de Ingenieria y Ciencias Geologicas, Universidad Catolica del Norte (Chile); Velasco, Antonio [Centro Nacional de Investigacion y Capacitacion Ambiental del Instituto Nacional de Ecologia (CENICA-INE), Av. San Rafael Atlixco 186, Col. Vicentina, Del. Iztapalapa, 09340, Mexico, DF (Mexico)

    2008-04-15

    The marine algae are considered an important biomass source; however, their utilization as energy source is still low around the world. The technical feasibility of marine algae utilization as a source of renewable energy was studied to laboratory scale. The anaerobic digestion of Macrocystis pyrifera, Durvillea antarctica and their blend 1:1 (w/w) was evaluated in a two-phase anaerobic digestion system, which consisted of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic filter (UAF). The results show that 70% of the total biogas produced in the system was generated in the UAF, and both algae species have similar biogas productions of 180.4({+-}1.5) mL g{sup -1} dry algae d{sup -1}, with a methane concentration around 65%. The same methane content was observed in biogas yield of algae blend; however, a lower biogas yield was obtained. In conclusion, either algae species or their blend can be utilized to produce methane gas in a two-phase digestion system. (author)

  13. Comparison of the performance of MBBR and SBR systems for the treatment of anaerobic reactor biowaste effluent.

    Science.gov (United States)

    Comett-Ambriz, I; Gonzalez-Martinez, S; Wilderer, P

    2003-01-01

    Anaerobic reactor biowaste effluent was treated with biofilm and activated sludge sequencing batch reactors to compare the performance of both systems. The treatment targets were organic carbon removal and nitrification. The pilot plant was operated in two phases. During the first phase, it was operated like a Moving Bed Biofilm Reactor (MBBR) with the Natrix media, with a specific surface area of 210 m2/m3. The MBBR was operated under Sequencing Batch Reactor (SBR) modality with three 8-hour cycles per day over 70 days. During the second phase of the experiment, the pilot plant was operated over 79 days as a SBR. In both phases the influent was fed to the reactor at a flow rate corresponding to a Hydraulic Retention Time (HRT) of 4 days. Both systems presented a good carbon removal for this specific wastewater. The Chemical Oxygen Demand (COD) total removal was 53% for MBBR and 55% for SBR. MBBR offered a higher dissolved COD removal (40%) than SBR (30%). The limited COD removal achieved is in agreement with the high COD to BOD5 ratio (1/3) of the influent wastewater. In both systems a complete nitrification was obtained. The different efficiencies in both systems are related to the different biomass concentrations.

  14. Design of A solar Thermophilic Anaerobic Reactor for Small Farms

    NARCIS (Netherlands)

    Mashad, El H.; Loon, van W.K.P.; Zeeman, G.; Bot, G.P.A.; Lettinga, G.

    2004-01-01

    A 10 m(3) completely stirred tank reactor has been designed for anaerobic treatment of liquid cow manure under thermophilic conditions (50degreesC), using a solar heating system mounted on the reactor roof. Simulation models for two systems have been developed. The first system consists of loose com

  15. ANAEROBIC DIGESTION AND THE DENITRIFICATION IN UASB REACTOR

    Directory of Open Access Journals (Sweden)

    José Tavares de Sousa

    2008-01-01

    Full Text Available The environmental conditions in Brazil have been contributing to the development of anaerobic systems in the treatment of wastewaters, especially UASB - Upflow Anaerobic Sludge Blanket reactors. The classic biological process for removal of nutrients uses three reactors - Bardenpho System, therefore, this work intends an alternative system, where the anaerobic digestion and the denitrification happen in the same reactor reducing the number of reactors for two. The experimental system was constituted by two units: first one was a nitrification reactor with 35 L volume and 15 d of sludge age. This system was fed with raw sanitary waste. Second unit was an UASB, with 7.8 L and 6 h of hydraulic detention time, fed with ¾ of effluent nitrification reactor and ¼ of raw sanitary waste. This work had as objective to evaluate the performance of the UASB reactor. In terms of removal efficiency, of bath COD and nitrogen, it was verified that the anaerobic digestion process was not affected. The removal efficiency of organic material expressed in COD was 71%, performance already expected for a reactor of this type. It was also observed that the denitrification process happened; the removal nitrate efficiency was 90%. Therefore, the denitrification process in reactor UASB is viable.

  16. Essential metal depletion in an anaerobic reactor.

    Science.gov (United States)

    Osuna, M B; Iza, J; Zandvoort, M; Lens, P N L

    2003-01-01

    The effect of the absence of trace elements on the conversion of a mixture of volatile fatty acids by a distillery anaerobic granular sludge was investigated. Two UASB reactors were operated under identical operational conditions except for the influent trace metal concentrations, during 140 days. Experiments were carried out in three periods, where different organic loading rates (OLR) were applied to the reactors. The total trace metal concentration steadily decreased at a rate of 48 microg metal/g TS.d in the deprived reactor (down to 35% of their initial value). In contrast, trace metals accumulated in granules present in the control reactor. At the end of the experiment, the COD removal efficiencies were 99% and 77% for the control and deprived reactors, respectively, due to the lack of propionate conversion. Cobalt sorption experiments were carried out in order to study its speciation, and its effects on the speciation of other metals as well. A paper mill wastewater treating granular sludge was also included in the study as a comparison. Results obtained showed that the principal metal forms normally associated with any sludge are a function of each soluble metal concentration in the system, and the characteristics of the particular sludge.

  17. Tar water digestion in an upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

    Skibsted Mogensen, A.; Angelidaki, I.; Schmidt, J.E.; Ahring, B.K. [Technical Univ., Dept. of Environmental Science and Engineering, Lyngby (Denmark)

    1998-08-01

    The water from the gasification and wet oxidised tar water has been digested anaerobically in UASB reactors and were digested in respectively 10 and 50% in batches. Though the tar water show inhibition at very low concentrations to aerobic microorganisms, the granular sludge used in UASB reactors degrades tar water in concentrations that reveal total inhibition of e.g. bacteria conducting the nitrification process. The value of waste waters are determined, showing that the tar water produces more biogas in the anaerobic digestion. A wide range of xenobiotics, especially phenolic compounds can be transformed in the anaerobic digestion process. Seven phenolic are followed in batch experiments and UASB reactor experiments, and their particular fate in the anaerobic systems embody large differences in the transformation pattern. (au) 24 refs.

  18. Production of biohythane from food waste via an integrated system of continuously stirred tank and anaerobic fixed bed reactors.

    Science.gov (United States)

    Yeshanew, Martha M; Frunzo, Luigi; Pirozzi, Francesco; Lens, Piet N L; Esposito, Giovanni

    2016-11-01

    The continuous production of biohythane (mixture of biohydrogen and methane) from food waste using an integrated system of a continuously stirred tank reactor (CSTR) and anaerobic fixed bed reactor (AFBR) was carried out in this study. The system performance was evaluated for an operation period of 200days, by stepwise shortening the hydraulic retention time (HRT). An increasing trend of biohydrogen in the CSTR and methane production rate in the AFBR was observed regardless of the HRT shortening. The highest biohydrogen yield in the CSTR and methane yield in the AFBR were 115.2 (±5.3)L H2/kgVSadded and 334.7 (±18.6)L CH4/kgCODadded, respectively. The AFBR presented a stable operation and excellent performance, indicated by the increased methane production rate at each shortened HRT. Besides, recirculation of the AFBR effluent to the CSTR was effective in providing alkalinity, maintaining the pH in optimal ranges (5.0-5.3) for the hydrogen producing bacteria.

  19. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;

    2003-01-01

    control approaches that have been used are comprehensively described. These include simple and adaptive controllers, as well as more recent developments such as fuzzy controllers, knowledge-based controllers and controllers based on neural networks.......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  20. Treatment of petroleum refinery wastewater using a sequential anaerobic-aerobic moving-bed biofilm reactor system based on suspended ceramsite.

    Science.gov (United States)

    Lu, Mang; Gu, Li-Peng; Xu, Wen-Hao

    2013-01-01

    In this study, a novel suspended ceramsite was prepared, which has high strength, optimum density (close to water), and high porosity. The ceramsite was used to feed a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic (A/O) arrangement to treat petroleum refinery wastewater for simultaneous removal of chemical oxygen demand (COD) and ammonium. The hydraulic retention time (HRT) of the anaerobic-aerobic MBBR system was varied from 72 to 18 h. The anaerobic-aerobic system had a strong tolerance to shock loading. Compared with the professional emission standard of China, the effluent concentrations of COD and NH3-N in the system could satisfy grade I at HRTs of 72 and 36 h, and grade II at HRT of 18 h. The average sludge yield of the anaerobic reactor was estimated to be 0.0575 g suspended solid/g CODremoved. This work demonstrated that the anaerobic-aerobic MBBR system using the suspended ceramsite as bio-carrier could be applied to achieving high wastewater treatment efficiency.

  1. Essential metal depletion in an anaerobic reactor

    NARCIS (Netherlands)

    Osuna, M.B.; Iza, J.M.; Zandvoort, M.H.; Lens, P.N.L.

    2003-01-01

    The effect of the absence of trace elements on the conversion of a mixture of volatile fatty acids by a distillery anaerobic granular sludge was investigated. Two UASB reactors were operated under identical operational conditions except for the influent trace metal concentrations, during 140 days. E

  2. Essential metal depletion in an anaerobic reactor.

    NARCIS (Netherlands)

    Osuna, M.B.; Iza, J.M.; Zandvoort, M.H.; Lens, P.N.L.

    2003-01-01

    The effect of the absence of trace elements on the conversion of a mixture of volatile fatty acids by a distillery anaerobic granular sludge was investigated. Two UASB reactors were operated under identical operational conditions except for the influent trace metal concentrations, during 140 days. E

  3. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;

    2003-01-01

    measurements are reviewed in detail. In the sequel, possible manipulated variables, such as the hydraulic retention time, the organic loading rate, the sludge retention time, temperature, pH and alkalinity are evaluated with respect to the two main reactor types: high-rate and low-rate. Finally, the different......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  4. Hydrolytic anaerobic reactor and aerated constructed wetland systems for municipal wastewater treatment - HIGHWET project.

    Science.gov (United States)

    Pascual, A; de la Varga, D; Arias, C A; Van Oirschot, D; Kilian, R; Álvarez, J A; Soto, M

    2017-01-01

    The HIGHWET project combines the hydrolytic up-flow sludge bed (HUSB) anaerobic digester and constructed wetlands (CWs) with forced aeration for decreasing the footprint and improving effluent quality. The HIGHWET plant in A Coruña (NW of Spain) treating municipal wastewater consists of a HUSB and four parallel subsurface horizontal flow (HF) CWs. HF1, HF2 and HF3 units are fitted with forced aeration, while the control HF4 is not aerated. All the HF units are provided with effluent recirculation, but different heights of gravel bed (0.8 m in HF1 and HF2, and 0.5 m in HF3 and HF4) are implemented. Besides, a tobermorite-enriched material was added in the HF2 unit in order to improve phosphorus removal. The HUSB 76-89% of total suspended solids (TSS) and about 40% of chemical oxygen demand (COD) and biological oxygen demand (BOD). Aerated HF units reached above 96% of TSS, COD and BOD at a surface loading rate of 29-47 g BOD5/m(2)·d. An aeration regime ranging from 5 h on/3 h off to 3 h on/5 h off was found to be adequate to optimize nitrogen removal, which ranged from 53% to 81%. Average removal rates of 3.4 ± 0.4 g total nitrogen (TN)/m(2)·d and 12.8 ± 3.7 g TN/m(3)·d were found in the aerated units, being 5.5 and 4.1 times higher than those of the non-aerated system. The tobermorite-enriched HF2 unit showed a distinct higher phosphate (60-67%) and total phosphorus (54%) removal.

  5. Autogenerative high pressure digestion: anaerobic digestion and biogas upgrading in a single step reactor system

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Fermoso, F.G.; Weijma, J.; Zagt, K.; Lier, van J.B.

    2011-01-01

    Conventional anaerobic digestion is a widely applied technology to produce biogas from organic wastes and residues. The biogas calorific value depends on the CH4 content which generally ranges between 55 and 65%. Biogas upgrading to so-called ‘green gas’, with natural gas quality, generally proceeds

  6. Vinasses treatment in anaerobic fludized bed reactor.

    Directory of Open Access Journals (Sweden)

    Francisco J. C. Terán

    2009-03-01

    Full Text Available The agricultural use of vinasse produced by the sugar industry has gone through many changes over the years. Coupled with concern over the increased agronomic efficiency and optimizing the management of the use of such waste, you can highlight the major global ecological awareness, developed after 90s. This study aims at the construction and operation of a reactor anaerobic cracker (RALF on pilot scale to verify the burden of chemical demand of oxygen (DQO of vinasse, under mesophilic. The stillage used for feeding the reactor was from a sugar cane processing plant, located in the city of Regente Feijó, São Paulo State. The inoculum was anaerobic sludge from a reactor and upward flow anaerobic sludge blanket (UASB treating wastewater from a factory of soda. The concentrations of vinasse to be treated ranged 17,239 mg DQO L-1 up to 28,174 mg DQO L-1. The effluent pH was maintained between 6.4 and 8.6 during the research. The productivity of biogas in the reactor has not achieved the expected rates, reaching only 46 mL day-1. Maximum efficiency attained during operation was 51.1 %, corresponding to a 14-day operation time, vinasses organic loading of 19.5 kg DQO m-3 dia-1 and to an hydraulic detention time of one day.

  7. Reduction of the hydraulic retention time at constant high organic loading rate to reach the microbial limits of anaerobic digestion in various reactor systems.

    Science.gov (United States)

    Ziganshin, Ayrat M; Schmidt, Thomas; Lv, Zuopeng; Liebetrau, Jan; Richnow, Hans Hermann; Kleinsteuber, Sabine; Nikolausz, Marcell

    2016-10-01

    The effects of hydraulic retention time (HRT) reduction at constant high organic loading rate on the activity of hydrogen-producing bacteria and methanogens were investigated in reactors digesting thin stillage. Stable isotope fingerprinting was additionally applied to assess methanogenic pathways. Based on hydA gene transcripts, Clostridiales was the most active hydrogen-producing order in continuous stirred tank reactor (CSTR), fixed-bed reactor (FBR) and anaerobic sequencing batch reactor (ASBR), but shorter HRT stimulated the activity of Spirochaetales. Further decreasing HRT diminished Spirochaetales activity in systems with biomass retention. Based on mcrA gene transcripts, Methanoculleus and Methanosarcina were the predominantly active in CSTR and ASBR, whereas Methanosaeta and Methanospirillum activity was more significant in stably performing FBR. Isotope values indicated the predominance of aceticlastic pathway in FBR. Interestingly, an increased activity of Methanosaeta was observed during shortening HRT in CSTR and ASBR despite high organic acids concentrations, what was supported by stable isotope data.

  8. Upflow anaerobic sludge blanket reactor--a review.

    Science.gov (United States)

    Bal, A S; Dhagat, N N

    2001-04-01

    Biological treatment of wastewater basically reduces the pollutant concentration through microbial coagulation and removal of non-settleable organic colloidal solids. Organic matter is biologically stabilized so that no further oxygen demand is exerted by it. The biological treatment requires contact of the biomass with the substrate. Various advances and improvements in anaerobic reactors to achieve variations in contact time and method of contact have resulted in development of in suspended growth systems, attached growth or fixed film systems or combinations thereof. Although anaerobic systems for waste treatment have been used since late 19th century, they were considered to have limited treatment efficiencies and were too slow to serve the needs of a quickly expanding wastewater volume, especially in industrialized and densely populated areas. At present aerobic treatment is the most commonly used process to reduce the organic pollution level of both domestic and industrial wastewaters. Aerobic techniques, such as activated sludge process, trickling filters, oxidation ponds and aerated lagoons, with more or less intense mixing devices, have been successfully installed for domestic wastewater as well as industrial wastewater treatment. Anaerobic digestion systems have undergone modifications in the last two decades, mainly as a result of the energy crisis. Major developments have been made with regard to anaerobic metabolism, physiological interactions among different microbial species, effects of toxic compounds and biomass accumulation. Recent developments however, have demonstrated that anaerobic processes might be an economically attractive alternative for the treatment of different types of industrial wastewaters and in (semi-) tropical areas also for domestic wastewaters. The anaerobic degradation of complex, particulate organic matter has been described as a multistep process of series and parallel reactions. It involves the decomposition of organic and

  9. Plants Growth Rate in Evapotranspiration continuous system reactors as the 2nd Treatment at Anaerobic-evapotranspiration system with High Strength Ammonium in Leachate Influent

    Directory of Open Access Journals (Sweden)

    Badrus Zaman

    2014-05-01

    Full Text Available Ammonium is one of parameter which responsible to leachate toxicity. Preliminary research was shown that the Fimbristylis globulosa (water plant, Alocasia macrorrhiza (terrestrial plant and Eleusine indica (terrestrial grass were potential plants for used as object in evaporation reactor system with high strength ammonium  concentration in leachate treatment. This research was integrated of anaerobic system with evapotranspiration system with continuous influent using ammonium concentration in leachate was 2000 mg/l NH4-N. Plants growth rate was analyzed for 25 days operated. The result shown that average of thallus growth rate of Fimbristylis globulosa was 17,5 cm d-1. The average of leaf and thallus growth rate of Alocasia macrorrhiza was 18,1 cm d-1 and 3,2 cm d-1 respectively. The average of blade and thallus of Eleusine indica were same that was 4,7 cm d-1.This research conclude that integration system of anaerobic and evpotranspiration was be potential used for high strength ammonium in leachate treatment.

  10. Conversion of Methanogenic Substrates in Anaerobic Reactors

    NARCIS (Netherlands)

    Gonzalez-Gil, G.

    2000-01-01

    The EGSB systems represents an attractive option to extend further the use of anaerobic technology for wastewater treatment, particularly with respect to waste streams originating from chemical industries. Frequently chemical waste streams are unbalanced with respect to nutrients and/or micronutrien

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  12. Modeling for Anaerobic Fixed-Bed Biofilm Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B. Y. M.; Pfeffer, J. T.

    1989-06-01

    The specific objectives of this research were: 1. to develop an equilibrium model for chemical aspects of anaerobic reactors; 2. to modify the equilibrium model for non-equilibrium conditions; 3. to incorporate the existing biofilm models into the models above to study the biological and chemical behavior of the fixed-film anaerobic reactors; 4. to experimentally verify the validity of these models; 5. to investigate the biomass-holding ability of difference packing materials for establishing reactor design criteria.

  13. Removal of oxytetracycline (OTC) in a synthetic pharmaceutical wastewater by a sequential anaerobic multichamber bed reactor (AMCBR)/completely stirred tank reactor (CSTR) system: biodegradation and inhibition kinetics.

    Science.gov (United States)

    Sponza, Delia Teresa; Çelebi, Hakan

    2012-01-01

    An anaerobic multichamber bed reactor (AMCBR) was effective in removing both molasses-chemical oxygen demand (COD), and the antibiotic oxytetracycline (OTC). The maximum COD and OTC removals were 99% in sequential AMCBR/completely stirred tank reactor (CSTR) at an OTC concentration of 300 mg L(-1). 51%, 29% and 9% of the total volatile fatty acid (TVFA) was composed of acetic, propionic acid and butyric acids, respectively. The OTC loading rates at between 22.22 and 133.33 g OTC m(-3) d(-1) improved the hydrolysis of molasses-COD (k), the maximum specific utilization of molasses-COD (k(mh)) and the maximum specific utilization rate of TVFA (k(TVFA)). The direct effect of high OTC loadings (155.56 and -177.78 g OTC m(-3) d(-1)) on acidogens and methanogens were evaluated with Haldane inhibition kinetic. A significant decrease of the Haldane inhibition constant was indicative of increases in toxicity at increasing loading rates.

  14. Comparison of the sensitivities of fish, Microtox and Daphnia-magna bioassays to amoxycillin in anaerobic/aerobic sequential reactor systems.

    Science.gov (United States)

    Çelebi, H; Sponza, D T

    2012-01-01

    In this study the anaerobic treatability of amoxycillin (AMX) was investigated in a laboratory-scale anaerobic multi-chamber bed reactor (AMCBR)/aerobic continuously stirred tank reactor (CSTR) system. The chemical oxygen demand (COD) and AMX removal efficiencies were around 94% in the AMCBR reactor at hydraulic retention times (HRTs) between 2.25 and 5.5 days. Decreasing the HRT appeared not to have a significant effect on the performance of the AMCBR up to a HRT of 1.13 days. The maximum methane production rate and methane percentage were around 1,100-1,200 mL/day and 55%, respectively, at HRTs between 2.25 and 5.5 days. The decrease in HRT to 1.5 days decreased slightly the gas productions (1,000 mL/day and 500 mL for total and methane gases) and methane percentage (45%). The AMCBR recovered back to its baseline performance within a couple of days. The acute toxicity of 150 mg/L AMX was monitored with Daphnia magna, Lepistes sp., and Vibrio fischeri acute toxicity tests. The acute toxicity removals were 98, 96 and 96% for V. fischeri, D. magna and Lepistes sp. in the effluent of the sequential system treating 150 mg/L AMX at HRTs of 2.25-5.5 days. Among the trophic organisms used in the acute toxicity tests the most sensitive organism was found to be bacteria (V. fischeri) while the most resistant organism was found to be fish (Lepistes sp.).

  15. Anaerobic degradation of linear alkylbenzene sulfonate in fluidized bed reactor

    OpenAIRE

    2010-01-01

    An anaerobic fluidized bed reactor was used to assess the degradation of the surfactant linear alkylbenzene sulfonate (LAS). The reactor was inoculated with sludge from an UASB reactor treating swine wastewater and was fed with a synthetic substrate supplemented with LAS. Sand was used as support material for biomass immobilization. The reactor was kept in a controlled temperature chamber (30±1 ºC) and operated with a hydraulic retention time (HRT) of 18 h. The LAS concentration was gradually...

  16. Kinetics of propionate conversion in anaerobic continuously stirred tank reactors

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik; Mladenovska, Zuzana; Ahring, Birgitte Kiær

    2008-01-01

    The kinetic parameters of anaerobic propionate degradation by biomass from 7 continuously stirred tank reactors differing in temperature, hydraulic retention time and substrate composition were investigated. In substrate-depletion experiments (batch) the maximum propionate degradation rate, A......-m, was estimated. The results demonstrate that the rate of endogenous substrate (propionate) production should be taken into account when estimating kinetic parameters in biomass from manure-based anaerobic reactors....

  17. Detoxification of tar water by anaerobic treatment in an UASB reactor - A study of the degradation of phenolic compounds in a combined denitrifying and anaerobic UASB reactor

    Energy Technology Data Exchange (ETDEWEB)

    Skibsted Mogensen, A.; Schmidt, J.E.; Ahring, B.K. [Technical Univ., Dept. of Environmental Science and Engineering, Lyngby (Denmark)

    1998-08-01

    The digestion of pyrolysis condensate (PC) in two combined anaerobic and denitrifying upflow anaerobic sludge blanket (UASB) reactors was studied. A COD removal of 80% was achieved with an influent concentration of 1.43% PC{sub pH}. When the reactor was fed with 100% PC during a period of 10 days good reactor operation was observed. Despite less than one retention time of operation, the results indicated clearly, that PC could be used as substrate in the biogas process, even in very high concentrations. A combined anaerobic and denitrifying UASB reactor was successfully digesting 5.5% of wet oxidised PC, but further loading increments deteriorated the anaerobic digestion process. The detoxification of PC was studied by determining the degradation of phenols during reactor operation and the toxicity of PC was decreased more than 77 times witnessed through decreased inhibition of the nitrification process. Phenol, methyl and dimethyl phenols along with methoxyphenols were shown to be degraded within the reactor systems. Degradation rates for phenol and substituted phenols were determined by the reactor experiment indicating that the biomass was selective towards the substrates. Maximum growth rates and half saturation constants for phenol, 4-Methylphenol and 2-Methoxy-4-methylphenol were determined in batch experiments. The degradation rates of phenols determined in batches were significantly higher compared to degradation rates observed in the reactor systems digesting pyrolysis condensate. Determination of the population of methanogens revealed, that Methanosarcina was found only in one reactor, while Methanobacterium and Methanosaeta were found in reactors and inoculum. A UASB reactor was designed for the treatment of pyrolysis condensate at the gasification plant at Harbooere, Denmark. (au) 35 refs.

  18. Optimization of the purification process of wine lees through anaerobic filter reactors. Optimizacion del proceso de depuracion de vinazas de vino mediante reactores tipo filtro anaerobio

    Energy Technology Data Exchange (ETDEWEB)

    Nebot Sanz, E.; Romero Garcia, L.I.; Quiroga Alonso, J.M.; Sales Marquez, D. (Departamento de Ingenieria Quimica, Universidad de Cadiz, Cadiz (Spain))

    1994-01-01

    In this work, the optimization of thermophilic anaerobic process, using Anaerobic Filter technology was studied. Feed of the Anaerobic Filter was wine-distillery wastewaters. The experiments developed were carried out at lab-scale downflow anaerobic filter reactors. Reactors were filled with a high porous plastic media (Flocor-R). The media support entities have a high surface/volume ratio. Test were run to determine the maximum organic load attainable in the system for wich both, the depurative efficiency and the methane production were optimum. Likewise, the effect of organic load on the anaerobic filter performance were studied. (Author) 15 refs. (Author)

  19. Anaerobic protozoa and their growth in biomethanation systems.

    Science.gov (United States)

    Priya, M; Haridas, Ajit; Manilal, V B

    2008-04-01

    This study was to investigate growth of protozoa and its influence on biodegradation in anaerobic treatment systems. It was done by specifically controlling and monitoring growth of protozoa versus degradation in continuous stirred anaerobic reactors and batch anaerobic reactors. Occurrence of a diverse protozoa population such as the ciliates, Prorodon, Vorticella, Cyclidium, Spathidium, Loxodes, Metopus were observed in stable anaerobic systems and the flagellates, Rhynchomonas, Naeglaria, Amoeboflagellates, Tetramitus, Trepomonas and Bodo during increased VFA concentration and affected periods of biomethanation. The abundance of ciliates in the anaerobic system had significant correlation with the reduction of MLSS, increased rate of COD removal and higher methane production. The results of this study thus tend to relate increased anaerobic degradation with the abundance of protozoa, mainly ciliates, which indicate their possible involvement in the process. Present study also reveals that performance of anaerobic process can be assessed by monitoring the protozoa population in the system.

  20. Microbial community structure and diversity in an integrated system of anaerobic-aerobic reactors and a constructed wetland for the treatment of tannery wastewater in Modjo, Ethiopia.

    Directory of Open Access Journals (Sweden)

    Adey Feleke Desta

    Full Text Available A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery wastewater in Modjo town, Ethiopia. The system has been running with removal efficiencies ranging from 94%-96% for COD, 91%-100% for SO4(2- and S(2-, 92%-94% for BOD, 56%-82% for total Nitrogen and 2%-90% for NH3-N. 16S rRNA gene clone libraries were constructed and microbial community assemblies were determined by analysis of a total of 801 unique clone sequences from all the sites. Operational Taxonomic Unit (OTU--based analysis of the sequences revealed highly diverse communities in each of the reactors and the constructed wetland. A total of 32 phylotypes were identified with the dominant members affiliated to Clostridia (33%, Betaproteobacteria (10%, Bacteroidia (10%, Deltaproteobacteria (9% and Gammaproteobacteria (6%. Sequences affiliated to the class Clostridia were the most abundant across all sites. The 801 sequences were assigned to 255 OTUs, of which 3 OTUs were shared among the clone libraries from all sites. The shared OTUs comprised 80 sequences belonging to Clostridiales Family XIII Incertae Sedis, Bacteroidetes and unclassified bacterial group. Significantly different communities were harbored by the anaerobic, aerobic and rhizosphere sites of the constructed wetland. Numerous representative genera of the dominant bacterial classes obtained from the different sample sites of the integrated system have been implicated in the removal of various carbon- containing pollutants of natural and synthetic origins. To our knowledge, this is the first report of microbial community structure in tannery wastewater treatment plant from Ethiopia.

  1. COD fractions of leachate from aerobic and anaerobic pilot scale landfill reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bilgili, M. Sinan [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ahmetd@yildiz.edu.tr; Akkaya, Ebru [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ekoca@yildiz.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: bozkaya@yildiz.edu.tr

    2008-10-01

    One of the most important problems with designing and maintaining a landfill is managing leachate that generated when water passes through the waste. In this study, leachate samples taken from aerobic and anaerobic landfill reactors operated with and without leachate recirculation are investigated in terms of biodegradable and non-biodegradable fractions of COD. The operation time is 600 days for anaerobic reactors and 250 days for aerobic reactors. Results of this study show that while the values of soluble inert COD to total COD in the leachate of aerobic landfill with leachate recirculation and aerobic dry reactors are determined around 40%, this rate was found around 30% in the leachate of anaerobic landfill with leachate recirculation and traditional landfill reactors. The reason for this difference is that the aerobic reactors generated much more microbial products. Because of this condition, it can be concluded that total inert COD/total COD ratios of the aerobic reactors were 60%, whereas those of anaerobic reactors were 50%. This study is important for modeling, design, and operation of landfill leachate treatment systems and determination of discharge limits.

  2. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor.

    Science.gov (United States)

    Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Li, Xu-Dong

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m(3) of biogas per m(3) of POME which was utilized for electricity generation.

  3. Treatment of slaughterhouse wastewater in anaerobic sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Masse, D. I.; Masse, L. [Agriculture and Agri-Food Canada, Lennoxville, PQ (Canada)

    2000-09-01

    Slaughterhouse waste water was treated in anaerobic sequencing batch reactors operated at 30 degrees C. Two of the batch reactors were seeded with anaerobic granular sludge from a milk processing plant reactor; two others received anaerobic non-granulated sludge from a municipal waste water treatment plant. Influent total chemical oxygen demand was reduced by 90 to 96 per cent at organic loading rates ranging from 2.07 kg to 4.93 kg per cubic meter. Reactors seeded with municipal sludge performed slightly better than those containing sludge from the milk processing plant. The difference was particularly noticeable during start-up, but the differences between the two sludges were reduced with time. The reactors produced a biogas containing 75 per cent methane. About 90.5 per cent of the chemical oxygen demand removed was methanized; volatile suspended solids accumulation was determined at 0.068 kg per kg of chemical oxygen demand removed. The high degree of methanization suggests that most of the soluble and suspended organic material in slaughterhouse waste water was degraded during the treatment in the anaerobic sequencing batch reactors. 30 refs., 1 tab., 6 figs.

  4. Effects of shock 2,4-dichlorophenol (DCP) and cod loading rates on the removal of 2,4-DCP in a sequential upflow anaerobic sludge blanket/aerobic completely stirred tank reactor system.

    Science.gov (United States)

    Uluköy, A; Sponza, D T

    2008-04-01

    The treatability of 2,4-dwichlorophenol (DCP) was studied in an anaerobic/aerobic sequential reactor system. Laboratory scale upflow anaerobic sludge blanket (UASB) reactor/completely stirred tank reactors (CSTR) were operated at constant 2,4-DCP concentrations, and increasing chemical oxygen demand (COD) loading rates. The effect of shock organic loading rates on 2,4-DCP, COD removal efficiencies and methane gas production were investigated in the UASB reactor. When the organic loading rate was increased from 3.6 g l(-1) d(-1) to 30.16 g l(-1) d(-1), the COD and 2,4-DCP removal efficiencies decreased from 80 to 25% and from 99 to 60% in the UASB reactor. The optimum organic loading rates for maximum 2,4-DCP (E=99-100%) and COD (E=65-85%) removal efficiencies were 25-30 and 8-20 g-COD l(-1) d(-1), respectively. The percentage of methane of the total gas varied between 70 and 80 while the organic loadings were 18 g-COD l(-1) d(-1) and 20.36 g-COD l(-1) d(-1), respectively. During 80 days of operation, 2,4-DCP concentration was found to be below 0.5 and 0.1 mg l(-1) in aerobic reactor effluent resulting in 78 and 100% removal efficiencies. When the hydraulic retention time (HRT) was 18.72 h, the 2,4-DCP removal efficiency was 97% in the aerobic reactor. The optimum COD removal efficiency was 78.83% in anaerobic reactor effluent at an influent COD loading rate of 7.238 g-COD l(-1) d(-1) while 83.6% maximum COD removal efficiency was obtained in the aerobic reactor, resulting in a total COD removal efficiency of 96.83% in the whole system. The 2,4-DCP removal efficiency was 99% in the sequential anaerobic (UASB)/aerobic (CSTR) reactor system at COD loading rates varying between 11.46 and 30.16 g-COD l(-1) d(-1).

  5. Removal of anaerobic soluble microbial products in a biological activated carbon reactor.

    Science.gov (United States)

    Dong, Xiaojing; Zhou, Weili; He, Shengbing

    2013-09-01

    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L.

  6. Anaerobic biodegradation of linear alkylbenzene sulfonate (LAS) in upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Sanz, José L; Culubret, Elayne; de Ferrer, Juan; Moreno, Alfonso; Berna, José L

    2003-01-01

    The anaerobic biodegradation of Linear Alkylbenzene Sulfonate (LAS) was studied in Upflow Anaerobic Sludge Blanket Reactors (UASB). One reactor was fed with easily degradable substrates and commercial LAS solution during a period of 3 months (Reactor 1), meanwhile a second reactor was fed with a commercial LAS solution without co-substrate (Reactor 2) during 4 months. Both reactors were operated with an organic loading rate of 4-5 mg-LAS/l x day and a hydraulic retention time of one day. The LAS biodegradation was determined by full mass balance. LAS was analysed by HPLC in the liquid phase (influent and effluent streams of the reactors) as well as in the solid phase (granular sludge used as biomass). The results indicate a high level of removal (primary biodegradation: 64-85%). Biodegradation was higher in the absence of external co-substrates than in the presence of additional sources of carbon. This indicates that the surfactant can be partially used as carbon and energy source by anaerobic bacteria. Under the operating conditions used, inhibition of the methanogenic activity or any other negative effects on the biomass due to the presence of LAS were not observed. The methanogenic activity remained high and stable throughout the experiment.

  7. Innovative microbial fuel cell for electricity production from anaerobic reactors

    DEFF Research Database (Denmark)

    Min, Booki; Angelidaki, Irini

    2008-01-01

    A submersible microbial fuel cell (SMFC) was developed by immersing an anode electrode and a cathode chamber in an anaerobic reactor. Domestic wastewater was used as the medium and the inoculum in the experiments. The SMFC could successfully generate a stable voltage of 0.428 ± 0.003 V with a fixed...

  8. Performance of a microbial fuel cell-based biosensor for online monitoring in an integrated system combining microbial fuel cell and upflow anaerobic sludge bed reactor.

    Science.gov (United States)

    Jia, Hui; Yang, Guang; Wang, Jie; Ngo, Huu Hao; Guo, Wenshan; Zhang, Hongwei; Zhang, Xinbo

    2016-10-01

    A hybrid system integrating a microbial fuel cell (MFC)-based biosensor with upflow anaerobic sludge blanket (UASB) was investigated for real-time online monitoring of the internal operation of the UASB reactor. The features concerned were its rapidity and steadiness with a constant operation condition. In addition, the signal feedback mechanism was examined by the relationship between voltage and time point of changed COD concentration. The sensitivity of different concentrations was explored by comparing the signal feedback time point between the voltage and pH. Results showed that the electrical signal feedback was more sensitive than pH and the thresholds of sensitivity were S=3×10(-5)V/(mg/L) and S=8×10(-5)V/(mg/L) in different concentration ranges, respectively. Although only 0.94% of the influent COD was translated into electricity and applied for biosensing, this integrated system indicated great potential without additional COD consumption for real-time monitoring.

  9. Zero valent iron simultaneously enhances methane production and sulfate reduction in anaerobic granular sludge reactors.

    Science.gov (United States)

    Liu, Yiwen; Zhang, Yaobin; Ni, Bing-Jie

    2015-05-15

    Zero valent iron (ZVI) packed anaerobic granular sludge reactors have been developed for improved anaerobic wastewater treatment. In this work, a mathematical model is developed to describe the enhanced methane production and sulfate reduction in anaerobic granular sludge reactors with the addition of ZVI. The model is successfully calibrated and validated using long-term experimental data sets from two independent ZVI-enhanced anaerobic granular sludge reactors with different operational conditions. The model satisfactorily describes the chemical oxygen demand (COD) removal, sulfate reduction and methane production data from both systems. Results show ZVI directly promotes propionate degradation and methanogenesis to enhance methane production. Simultaneously, ZVI alleviates the inhibition of un-dissociated H2S on acetogens, methanogens and sulfate reducing bacteria (SRB) through buffering pH (Fe(0) + 2H(+) = Fe(2+) + H2) and iron sulfide precipitation, which improve the sulfate reduction capacity, especially under deterioration conditions. In addition, the enhancement of ZVI on methane production and sulfate reduction occurs mainly at relatively low COD/ [Formula: see text] ratio (e.g., 2-4.5) rather than high COD/ [Formula: see text] ratio (e.g., 16.7) compared to the reactor without ZVI addition. The model proposed in this work is expected to provide support for further development of a more efficient ZVI-based anaerobic granular system.

  10. Biological sulphide removal from anaerobically treated domestic sewage: reactor performance and microbial community dynamics.

    Science.gov (United States)

    Garcia, Graziella Patrício Pereira; Diniz, Renata Côrtes Oliveira; Bicalho, Sarah Kinaip; Franco, Vitor Araujo de Souza; Gontijo, Eider Max de Oliveira; Toscano, Rodrigo Argolo; Canhestro, Kenia Oliveira; Santos, Merly Rita Dos; Carmo, Ana Luiza Rodrigues Dias; Lobato, Livia Cristina S; Brandt, Emanuel Manfred F; Chernicharo, Carlos A L; Calabria de Araujo, Juliana

    2015-01-01

    We developed a biological sulphide oxidation system and evaluated two reactors (shaped similar to the settler compartment of an up-flow anaerobic sludge blanket [UASB] reactor) with different support materials for biomass retention: polypropylene rings and polyurethane foam. The start-up reaction was achieved using microorganisms naturally occurring on the open surface of UASB reactors treating domestic wastewater. Sulphide removal efficiencies of 65% and 90% were achieved with hydraulic retention times (HRTs) of 24 and 12 h, respectively, in both reactors. However, a higher amount of elemental sulphur was formed and accumulated in the biomass from reactor 1 (20 mg S(0) g(-1) VTS) than in that from reactor 2 (2.9 mg S(0) g(-1) VTS) with an HRT of 24 h. Denaturing gradient gel electrophoresis (DGGE) results revealed that the the pink and green biomass that developed in both reactors comprised a diverse bacterial community and had sequences related to phototrophic green and purple-sulphur bacteria such as Chlorobium sp., Chloronema giganteum, and Chromatiaceae. DGGE band patterns also demonstrated that bacterial community was dynamic over time within the same reactor and that different support materials selected for distinct bacterial communities. Taken together, these results indicated that sulphide concentrations of 1-6 mg L(-1) could be efficiently removed from the effluent of a pilot-scale UASB reactor in two sulphide biological oxidation reactors at HRTs of 12 and 24 h, showing the potential for sulphur recovery from anaerobically treated domestic wastewater.

  11. Transformation of tetrachloroethene in an upflow anaerobic sludgeblanket reactor

    DEFF Research Database (Denmark)

    Christiansen, N.; Christensen, S.R.; Arvin, E.;

    1997-01-01

    Reductive dechlorination of tetrachloroethene was studied in a mesophilic upflow anaerobic sludge blanket reactor. Operating the reactor in batch mode the dynamic transformation of tetrachloroethene, trichloroethene and dichloroethene (DCE) was monitored. Tetrachloroethene was reductively...... dechlorinated to trichloroethene, which again was dechlorinated at the same rate as DCE was produced. DCE showed a lag period of 40 h before transformation was observed. During normal reactor operation trans-1,2-DCE was the major DCE isomer, followed by cis-1,2-DCE. Small amounts of 1,1-DCE but no vinyl...

  12. Use of an anaerobic sequencing batch reactor for parameter estimation in modelling of anaerobic digestion.

    Science.gov (United States)

    Batstone, D J; Torrijos, M; Ruiz, C; Schmidt, J E

    2004-01-01

    The model structure in anaerobic digestion has been clarified following publication of the IWA Anaerobic Digestion Model No. 1 (ADM1). However, parameter values are not well known, and uncertainty and variability in the parameter values given is almost unknown. Additionally, platforms for identification of parameters, namely continuous-flow laboratory digesters, and batch tests suffer from disadvantages such as long run times, and difficulty in defining initial conditions, respectively. Anaerobic sequencing batch reactors (ASBRs) are sequenced into fill-react-settle-decant phases, and offer promising possibilities for estimation of parameters, as they are by nature, dynamic in behaviour, and allow repeatable behaviour to establish initial conditions, and evaluate parameters. In this study, we estimated parameters describing winery wastewater (most COD as ethanol) degradation using data from sequencing operation, and validated these parameters using unsequenced pulses of ethanol and acetate. The model used was the ADM1, with an extension for ethanol degradation. Parameter confidence spaces were found by non-linear, correlated analysis of the two main Monod parameters; maximum uptake rate (k(m)), and half saturation concentration (K(S)). These parameters could be estimated together using only the measured acetate concentration (20 points per cycle). From interpolating the single cycle acetate data to multiple cycles, we estimate that a practical "optimal" identifiability could be achieved after two cycles for the acetate parameters, and three cycles for the ethanol parameters. The parameters found performed well in the short term, and represented the pulses of acetate and ethanol (within 4 days of the winery-fed cycles) very well. The main discrepancy was poor prediction of pH dynamics, which could be due to an unidentified buffer with an overall influence the same as a weak base (possibly CaCO3). Based on this work, ASBR systems are effective for parameter

  13. The efficiency of two anaerobic reactor components; Eficiencias de dos componentes de un reactor anaerobio

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E.; Mendez Novelo, R.; Magana Pietra, A. [Facultad de Ingenieria. Universidad de Yucatan (Mexico); Martinez Pereda, P.; Fernandez Villagomez, G. [Universidad Nacional Autonoma de Mexico. Division de Estudios de posgrado de la Facultad de Ingenieria. Mexico (Mexico)

    1997-09-01

    This study examined the behaviour of an anaerobic digester in treating pig farm sewage. The experimental model consisted of a UASB reactor at the bottom and a high-rate sedimentator at the top with a total capacity of 534 litres. The digester was installed on a pig farm and its performance under different operating conditions was determined, with hydraulic retention time (HRT) as the critical parameter for evaluating the anaerobic system`s efficiency. The results obtained during the experiment to establish the critical operating parameters are reported. The organic loads applied for a HRT of 1 day were 7.3 kg/m``3/day of total DQO and 3 kg/m``3/day of soluble DQO, following organic matter removal rates (as total DQO) of 36% and 49% respectively and removal rates (as soluble DQO) of 74% in the UASB and 8% in the sedimentator. The efficiency of the reactor as a whole at this HRT time was a removal rate of 74% of total DQO and 75% of soluble DQO. (Author) 25 refs.

  14. Anaerobic treatment of wastewater containing methanol in upflow anaerobic sludge bed (UASB) reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The direct conversion of methanol into methane is the main process in anaerobic treatment of methanol containing wastewater.However,acetic acid can also be produced from methanol theoretically,which may probably result in an abrupt pH drop and deteriorate the anaerobic process.Therefore,it is interesting to know what would really happen in an anaerobic reactor treating methanol wastewater.In this study,an up-flow anaerobic sludge bed (UASB) reactor treating methanol wastewater was operated.The chemical oxygen demand (COD),acetic acid and pH of the effluent were monitored at different loadings and influent alkalinity.The results showed that the anaerobic reactor could be operated steadily at as low as 119 mg/L of influent alkalinity and high organic loading rate with no obvious pH drops.Volatile fatty acids accumulation was not observed even at strong shock loadings.The microorganisms in the sludge at the end of the test became homogeneous in morphology,which were mainly spherical or spheroidal in shape.

  15. Adapting Dynamic Mathematical Models to a Pilot Anaerobic Digestion Reactor

    Directory of Open Access Journals (Sweden)

    F. Haugen, R. Bakke, and B. Lie

    2013-04-01

    Full Text Available A dynamic model has been adapted to a pilot anaerobic reactor fed diarymanure. Both steady-state data from online sensors and laboratory analysis anddynamic operational data from online sensors are used in the model adaptation.The model is based on material balances, and comprises four state variables,namely biodegradable volatile solids, volatile fatty acids, acid generatingmicrobes (acidogens, and methane generating microbes (methanogens. The modelcan predict the methane gas flow produced in the reactor. The model may beused for optimal reactor design and operation, state-estimation and control.Also, a dynamic model for the reactor temperature based on energy balance ofthe liquid in the reactor is adapted. This model may be used for optimizationand control when energy and economy are taken into account.

  16. Anaerobic degradation of linear alkylbenzene sulfonate in fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    L. L. Oliveira

    2010-12-01

    Full Text Available An anaerobic fluidized bed reactor was used to assess the degradation of the surfactant linear alkylbenzene sulfonate (LAS. The reactor was inoculated with sludge from an UASB reactor treating swine wastewater and was fed with a synthetic substrate supplemented with LAS. Sand was used as support material for biomass immobilization. The reactor was kept in a controlled temperature chamber (30±1 ºC and operated with a hydraulic retention time (HRT of 18 h. The LAS concentration was gradually increased from 8.2±1.3 to 45.8±5.4 mg.L-1. The COD removal was 91%, on average, when the influent COD was 645±49 mg.L-1. The results obtained by chromatographic analysis showed that the reactor removed 93% of the LAS after 270 days of operation.

  17. Degradation of formaldehyde in anaerobic sequencing batch biofilm reactor (ASBBR).

    Science.gov (United States)

    Pereira, N S; Zaiat, M

    2009-04-30

    The present study evaluated the degradation of formaldehyde in a bench-scale anaerobic sequencing batch reactor, which contained biomass immobilized in polyurethane foam matrices. The reactor was operated for 212 days at 35 degrees C with 8h sequential cycles, under different affluent formaldehyde concentrations ranging from 31.6 to 1104.4 mg/L (formaldehyde loading rates from 0.08 to 2.78 kg/m(3)day). The results indicate excellent reactor stability and over 99% efficiency in formaldehyde removal, with average effluent formaldehyde concentration of 3.6+/-1.7 mg/L. Formaldehyde degradation rates increased from 204.9 to 698.3mg/Lh as the initial concentration of formaldehyde was increased from around 100 to around 1100 mg/L. However, accumulation of organic matter was observed in the effluent (chemical oxygen demand (COD) values above 500 mg/L) due to the presence of non-degraded organic acids, especially acetic and propionic acids. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in the literature. The anaerobic degradation pathway can be associated with the formation of long-chain oligomers from formaldehyde. Such long- or short-chain polymers are probably the precursors of organic acid formation by means of acidogenic anaerobic microorganisms.

  18. Degradation of formaldehyde in anaerobic sequencing batch biofilm reactor (ASBBR)

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, N.S. [Laboratorio de Processos Biologicos (LPB), Departamento de Hidraulica e Saneamento, Escola de Engenharia de Sao Carlos (EESC), Universidade de Sao Paulo - USP, Engenharia Ambiental, Bloco 4-F, Av. Joao Dagnone, 1100 Santa Angelina, 13.563-120 Sao Carlos, SP (Brazil); Zaiat, M. [Laboratorio de Processos Biologicos (LPB), Departamento de Hidraulica e Saneamento, Escola de Engenharia de Sao Carlos (EESC), Universidade de Sao Paulo - USP, Engenharia Ambiental, Bloco 4-F, Av. Joao Dagnone, 1100 Santa Angelina, 13.563-120 Sao Carlos, SP (Brazil)], E-mail: zaiat@sc.usp.br

    2009-04-30

    The present study evaluated the degradation of formaldehyde in a bench-scale anaerobic sequencing batch reactor, which contained biomass immobilized in polyurethane foam matrices. The reactor was operated for 212 days at 35 deg. C with 8 h sequential cycles, under different affluent formaldehyde concentrations ranging from 31.6 to 1104.4 mg/L (formaldehyde loading rates from 0.08 to 2.78 kg/m{sup 3} day). The results indicate excellent reactor stability and over 99% efficiency in formaldehyde removal, with average effluent formaldehyde concentration of 3.6 {+-} 1.7 mg/L. Formaldehyde degradation rates increased from 204.9 to 698.3 mg/L h as the initial concentration of formaldehyde was increased from around 100 to around 1100 mg/L. However, accumulation of organic matter was observed in the effluent (chemical oxygen demand (COD) values above 500 mg/L) due to the presence of non-degraded organic acids, especially acetic and propionic acids. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in the literature. The anaerobic degradation pathway can be associated with the formation of long-chain oligomers from formaldehyde. Such long- or short-chain polymers are probably the precursors of organic acid formation by means of acidogenic anaerobic microorganisms.

  19. Innovative wastewater treatment using reversing anaerobic upflow system (RAUS)

    Energy Technology Data Exchange (ETDEWEB)

    Basu, S.K. [Univ. of Manitoba, Winnipeg, Manitoba (Canada). Environmental Engineering Div.

    1996-11-01

    Anaerobic processes are widely popular in the treatment of a variety of industrial wastewaters since the development of such high rate treatment processes like upflow anaerobic sludge blanket (UASB), anaerobic filter, and the fluidized-bed process. In order to devise a low cost/high technology system so that it would provide an economical solution to environmentally sound pollution control, the Reversing Anaerobic Upflow System (RAUS) was developed. The system consists of two anaerobic reactors connected to each other. At the beginning, one reactor is fed upwards with wastewater while the other acts as a settling tank. After a set interval of time, the flow is reversed such that the second reactor is fed with wastewater and the first one acts as the settler. This particular feeding pattern had shown improved settling characteristics and granulation of methanogenic biomass from research carried out at the Hannover University with different wastewaters. The biological reaction vessels to which wastewater is introduced intermittently functions basically as a sludge blanket type reactor although the costly integrated settling devices present in a typical UASB system are avoided. The RAUS combines three principle reactor configurations: (1) conventional with sludge recycling; (2) fill and draw or sequential batch, inflow maintained constant during feeding; (3) upflow anaerobic sludge blanket. A pilot scale RAUS was operated for 400 days using distillery wastewater consisting of molasses slop and bottle washing water mixed in the ratio 1:1. This paper discusses the results of pilot scale experiments.

  20. ATP content and biomass activity in sequential anaerobic/aerobic reactors

    Institute of Scientific and Technical Information of China (English)

    陈红

    2004-01-01

    Specific ATP content of volatile solids was measured to characterize the sludge activity in a sequential anaerobic/aerobic wastewater treatment system, with an upflow anaerobic sludge blanket (UASB) reactor and a three-phase aerobic fluidized bed (AFB) reactor. The wastewater COD level was 2000(3000 mg/L in simulation of real textile wastewater. The ATP content and the specific ATP contents of volatile solids at different heights of the UASB reactor and those of the suspended and immobilized biomass in the AFB reactor were measured. In the UASB reactor, the maximum value of specific ATP (0.85 mg ATP/g VS) was obtained at a hydraulic retention time (HRT) 7.14 h in the blanket solution. In the AFB reactor, the specific ATP content of suspended biomass was higher than that of immobilized biomass and increased with hydraulic retention time reaching a maximum value of 1.6 mg ATP/g VS at hydraulic retention time 4.35 h. The ATP content of anaerobes in the UASB effluent declined rapidly under aerobic conditions following a 2nd-order kinetic model.

  1. A built-in zero valent iron anaerobic reactor to enhance treatment of azo dye wastewater.

    Science.gov (United States)

    Zhang, Yaobin; Jing, Yanwen; Quan, Xie; Liu, Yiwen; Onu, Pascal

    2011-01-01

    Waste scrap iron was packed into an upflow anaerobic sludge blanket (UASB) reactor to form a zero valent iron (ZVI) - UASB reactor system for treatment of azo dye wastewater. The ZVI acted as a reductant to decrease ORP in the reactor by more than 40 mv and functioned as an acid buffer to increase the pH in the reactor from 5.44 to 6.29, both of which improved the performance of the anaerobic reactor. As a result, the removal of color and COD in this reactor was 91.7% and 53%, respectively, which was significantly higher than that of a reference UASB reactor without ZVI. The UV-visible spectrum demonstrated that absorption bands of the azo dye from the ZVI-UASB reactor were substantially reduced. The ZVI promoted methanogenesis, which was confirmed by an increase in CH(4) content in the biogas from 47.9% to 64.8%. The ZVI bed was protected well from rusting, which allowed it to function stably. The effluent could be further purified only by pH adjustment because the Fe(2+) released from ZVI served as a flocculent.

  2. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor

    Science.gov (United States)

    Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Li, Xu-Dong

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m3 of biogas per m3 of POME which was utilized for electricity generation. PMID:26167485

  3. Characteristics and hydrogen production efficiency in anaerobic baffled reactor (ABR) system%ABR发酵系统运行特性及产氢效能研究

    Institute of Scientific and Technical Information of China (English)

    郑国臣; 李建政; 昌盛; 张照韩; 官涤; 金羽; 郭静波; 卢海凤

    2013-01-01

    To solve the continuous-flow stirred tank reactor (CSTR) hydrogen system has low efficient and waste energy,a 3-compartment anaerobic baffled reactor (ABR), with an effective volume of 27.8L, was adapted and its performing characteristics and hydrogen production efficiency were investigated,using diluted molasses as the material. ABR had higher efficiency and lower energy consumption comparing with CSTR. ABR achieved stable ethanol type fermentation within 26d with 35℃ and initial COD of 5000mg/L, and the specific hydrogen production rate was 0.13L/(gMLVSSd) while that of CSTR under the same conditions was 0.06L/g MLVSS-d. Results showed that ABR was an ideal facility for hydrogen production from organic wastewater fermentation.%为解决连续流搅拌槽式反应器(CSTR)发酵制氢系统存在的不足,如单位基质氢气转化率低、因搅拌带来的耗能,抗负荷冲击能力不强等问题,开展了厌氧折流板反应器(ABR)发酵产氢的研究.结果表明,在35℃和进水COD 5000mg/L等条件下,ABR系统可在26d达到乙醇型发酵,其比产氢速率为0.13L/(gMLVSS.d),而在同样条件下,CSTR达到乙醇型发酵后,比产氢速率仅为0.06L/(gMLVSS.d).ABR通过生物相的分离,使产氢系统梯级利用有机物并达到深度产氢的目的.与CSTR相比,ABR具有较高的产氢活性、较低能源消耗等优点,是一种较为理想的有机废水发酵制氢反应设备.

  4. Anaerobic membrane bio-reactors for severe industrial effluents and urban spill waters: The AMBROSIUS project

    NARCIS (Netherlands)

    Van Lier, J.B.; Ozgun, H.; Ersahin, M.E.; Dereli, R.K.

    2013-01-01

    With growing application experiences from aerobic membrane bioreactors, combination of membrane and anaerobic processes become more and more attractive and feasible. In anaerobic membrane bioreactors (AnMBRs), biomass and particulate organic matter are physically retained inside the reactor, providi

  5. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis

    DEFF Research Database (Denmark)

    Cai, Weiwei; Han, Tingting; Guo, Zechong

    2016-01-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic...... AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070 mL CH4/mL reactor/day, which is 2.59 times higher than AD control reactor (0.027 m3 CH4/m3/d). And COD removal is increased ~15% over AD control. When changing to sludge...... indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid....

  6. Anaerobic wastewater treatment of concentrated sewage using a two-stage upflow anaerobic sludge blanket- anaerobic filter system.

    Science.gov (United States)

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

    2010-01-01

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

  7. Removal of anaerobic soluble microbial products in a biological activated carbon reactor

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Dong; Weili Zhou; Shengbing He

    2013-01-01

    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable.Focusing on the biodegradation of anaerobic SMP,the biological activated carbon (BAC) was introduced into the anaerobic system.The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors.The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2,i.e.,BAC) functioned as a polishing step to remove SMP produced in UASB1.The results showed that 90% of the SMP could be removed before granular activated carbon was saturated.After the saturation,the SMP removal decreased to 60% on the average.Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation.A strain of SMP-degrading bacteria,which was found highly similar to Klebsiella sp.,was isolated,enriched and inoculated back to the BAC reactor.When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3·day),the effluent from the BAC reactor could meet the discharge standard without further treatment.Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective,cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L.

  8. Anaerobic treatment performance and microbial population of thermophilic upflow anaerobic filter reactor treating awamori distillery wastewater.

    Science.gov (United States)

    Tang, Yue-Qin; Fujimura, Yutaka; Shigematsu, Toru; Morimura, Shigeru; Kida, Kenji

    2007-10-01

    Distillery wastewater from awamori making was anaerobically treated for one year using thermophilic upflow anaerobic filter (UAF) reactors packed with pyridinium group-containing nonwoven fabric material. The microbial structure and spatial distribution of microorganisms on the support material were characterized using molecular biological methods. The reactor steadily achieved a high TOC loading rate of 18 g/l/d with approximately 80% TOC removal efficiency when non-diluted wastewater was fed. The maximum TOC loading rate increased to 36 g/l/d when treating thrice-diluted wastewater. However, the TOC removal efficiency and gas evolution rate decreased compared with that when non-diluted wastewater was used. Methanogens closely related to Methanosarcina thermophila and Methanoculleus bourgensis and bacteria in the phyla Firmicutes and Bacteroidetes were predominant methanogens and bacteria in the thermophilic UFA reactor, as indicated by 16S rRNA gene clone analysis. Fluorescence in situ hybridization (FISH) results showed that a large quantity of bacterial cells adhered throughout the whole support, and Methanosarcina-like methanogens existed mainly in the relative outside region while Methanoculleus cells were located in the relative inner part of the support. The support material used proved to be an excellent carrier for microorganisms, and a UAF reactor using this kind of support can be used for high-rate treatment of awamori/shochu distillery wastewater.

  9. Cosmetic wastewater treatment by upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-30

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

  10. Cultivation of nitrite-dependent anaerobic methane-oxidizing bacteria: impact of reactor configuration.

    Science.gov (United States)

    Hu, Baolan; He, Zhanfei; Geng, Sha; Cai, Chen; Lou, Liping; Zheng, Ping; Xu, Xinhua

    2014-09-01

    Nitrite-dependent anaerobic methane oxidation (n-damo) is mediated by bacteria that anaerobically oxidize methane coupled with nitrite reduction and is a potential bioprocess for wastewater treatment. In this work, the effect of reactor configuration on n-damo bacterial cultivation was investigated. A magnetically stirred gas lift reactor (MSGLR), a sequencing batch reactor (SBR), and a continuously stirred tank reactor (CSTR) were selected to cultivate the bacteria. Microbial community was monitored by using quantitative PCR, 16S rRNA gene sequencing, pmoA gene sequencing, and fluorescence in situ hybridization (FISH). The effects of substrate inhibition, methane mass transfer, and biomass washout in the three reactors were focused on. The results indicated that the MSGLR had the best performance among the three reactor systems, with the highest total and specific n-damo activities. Its maximum volumetric nitrogen removal rate was up to 76.9 mg N L(-1) day(-1), which was higher than previously reported values (5.1-37.8 mg N L(-1) d(-1)).

  11. Anaerobic methanethiol degradation in upflow anaerobic sludge bed reactors at high salinity (> 0.5 M Na+)

    NARCIS (Netherlands)

    Leerdam, van R.C.; Bok, de F.A.M.; Lens, P.N.L.; Stams, A.J.M.; Janssen, A.J.H.

    2007-01-01

    The feasibility of anaerobic methanethiol (MT) degradation at elevated sodium concentrations was investigated in a mesophilic (30°C) lab-scale upflow anaerobic sludge bed (UASB) reactor, inoculated with estuarine sediment originating from the Wadden Sea (The Netherlands). MT was almost completely de

  12. A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors.

    Science.gov (United States)

    Robles, A; Latrille, E; Ruano, M V; Steyer, J P

    2017-01-01

    The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability even when operating at high VFA concentrations. Pilot results showed the potential of this control approach to maintain the process working properly under similar conditions to the ones expected at full-scale plants.

  13. Degradation of Reactive Black 5 dye using anaerobic/aerobic membrane bioreactor (MBR) and photochemical membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    You, Sheng-Jie, E-mail: sjyou@cycu.edu.tw [Department of Bioenvironmental Engineering and R and D Center for Membrane Technology, Chung Yuan Christian University, 200 Chung Pei Road, Chungli 32023, Taiwan (China); Damodar, Rahul A. [Department of Bioenvironmental Engineering and R and D Center for Membrane Technology, Chung Yuan Christian University, 200 Chung Pei Road, Chungli 32023, Taiwan (China); Hou, Sheng-Chon [Department of Civil Engineering, Chung Yuan Christian University, 200 Chung Pei Road, Chungli 32023, Taiwan (China)

    2010-05-15

    Three different types of advance treatment methods were evaluated for the degradation of Reactive Black 5 (RB5). The performance of two stage anaerobic SBR-aerobic MBR, anaerobic MBR with immobilized and suspended biocells and an integrated membrane photocatalytic reactor (MPR) using slurry UV/TiO{sub 2} system were investigated. The results suggest that, nearly 99.9% color removal and 80-95% organic COD and TOC removal can be achieved using different reactor systems. Considering the Taiwan EPA effluent standard discharge criteria for COD/TOC, the degree of treatment achieved by combining the anaerobic-aerobic system was found to be acceptable. Anew, Bacilluscereus, high color removal bacterium was isolated from Anaerobic SBR. Furthermore, when this immobilized into PVA-calcium alginate pellets, and suspended in the anaerobic MBR was able to achieve high removal efficiencies, similar to the suspended biocells system. However, the immobilized cell Anaerobic MBR was found to be more advantageous, due to lower fouling rates in the membrane unit. Results from slurry type MPR system showed that this system was capable of mineralizing RB5 dyes with faster degradation rate as compared to other systems. The reactor was also able to separate the catalyst effectively and perform efficiently without much loss of catalyst activity.

  14. Oxygen tolerance capacity of upflow anaerobic solid-state (UASS) with anaerobic filter (AF) system.

    Science.gov (United States)

    Meng, Yao; Jost, Carsten; Mumme, Jan; Wang, Kaijun; Linke, Bernd

    2016-07-01

    In order to investigate the oxygen tolerance capacity of upflow anaerobic solid-state (UASS) with anaerobic filter (AF) system, the effect of microaeration on thermophilic anaerobic digestion of maize straw was investigated under batch conditions and in the UASS with AF system. Aeration intensities of 0-431mL O2/gvs were conducted as pretreatment under batch conditions. Aeration pretreatment obviously enhanced anaerobic digestion and an aeration intensity of 431mL O2/gvs increased the methane yield by 82.2%. Aeration intensities of 0-355mL O2/gvs were conducted in the process liquor circulation of the UASS with AF system. Dissolved oxygen (DO) of UASS and AF reactors kept around 1.39±0.27 and 0.99±0.38mg/L, respectively. pH was relatively stable around 7.11±0.04. Volatile fatty acids and soluble chemical oxygen demand concentration in UASS reactor were higher than those in AF reactor. Methane yield of the whole system was almost stable at 85±7mL/gvs as aeration intensity increased step by step. The UASS with AF system showed good oxygen tolerance capacity.

  15. Design of an anaerobic hybrid reactor for industrial wastewater treatment; Diseno de reactores hibridos anaerobios para el tratamiento de aguas residuales industriales

    Energy Technology Data Exchange (ETDEWEB)

    Soroa del Campo, S.; Lopetegui Garnika, J.; Almandoz Peraita, A.; Garcia de las Heras, J. L.

    2005-07-01

    The application of the European legislation has promoted different strategies aimed at minimizing the biological sludge production during wastewater treatment. Anaerobic biological treatment is the clearest choice from a technical and economical point of view regarding industrial wastewater. In this context, a semi-industrial anaerobic hybrid reactor has been developed as an alternative technology to other anaerobic systems well-established in the market for the treatment of slaughterhouse wastewater. The The results have demonstrated that it is an effective, robust and easy to operate system. The sludge production has been reduced below 0.12 kg VS/kg COD removed, for COD removal efficiencies above 95%. (Author) 12 refs.

  16. Pretreatment of coking wastewater using anaerobic sequencing batch reactor (ASBR)

    Institute of Scientific and Technical Information of China (English)

    LI Bing; SUN Ying-lan; LI Yu-ying

    2005-01-01

    A laboratory-scale anaerobic sequencing batch reactor (ASBR) was used to pretreat coking wastewater. Inoculated anaerobic granular biomass was acclimated for 225 d to the coking wastewater, and then the biochemical methane potential (BMP)of the coking wastewater in the acclimated granular biomass was measured. At the same time, some fundamental technological factors, such as the filling time and the reacting time ratio (tf/tr), the mixing intensity and the intermittent mixing mode, that affect anaerobic pretreatment of coking wastewater with ASBR, were evaluated through orthogonal tests. The COD removal efficiency reached 38%~50% in the stable operation period with the organic loading rate of 0.37~0.54 kg COD/(m3.d) at the optimum conditions of tf/tr, the mixing intensity and the intermittent mixing mode. In addition, the biodegradability of coking wastewater distinctly increased after the pretreatment using ASBR. At the end of the experiment, the microorganism forms on the granulated sludge in the ASBR were observed using SEM (scanning electron microscope) and fluoroscope. The results showed that the dominant microorganism on the granular sludge was Methanosaeta instead of Methanosarcina dominated on the inoculated sludge.

  17. Anaerobic tapered fluidized bed reactor for starch wastewater treatment and modeling using multilayer perceptron neural network

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Anaerobic treatability of synthetic sago wastewater was investigated in a laboratory anaerobic tapered fluidized bed reactor (ATFBR) with a mesoporous granular activated carbon (GAC) as a support material. The experimental protocol was defined to examine the effect of the maximum organic loading rate (OLR), hydraulic retention time (HRT), the efficiency of the reactor and to report on its steady-state performance. The reactor was subjected to a steady-state operation over a range of OLR up to 85.44 kg COD/(m3·d). The COD removal efficiency was found to be 92% in the reactor while the biogas produced in the digester reached 25.38 m3/(m3·d) of the reactor. With the increase of OLR from 83.7 kg COD/(m3·d), the COD removal efficiency decreases. Also an artificial neural network (ANN) model using multilayer perceptron (MLP) has been developed for a system of two input variable and five output dependent variables. For the training of the input-output data, the experimental values obtained have been used. The output parameters predicted have been found to be much closer to the corresponding experimental ones and the model was validated for 30% of the untrained data. The mean square error (MSE) was found to be only 0.0146.

  18. Treatment of linear alkylbenzene sulfonate in a horizontal anaerobic immobilized biomass reactor.

    Science.gov (United States)

    Duarte, I C S; Oliveira, L L; Saavedra, N K; Fantinatti-Garboggini, F; Menezes, C B A; Oliveira, V M; Varesche, M B A

    2010-01-01

    Linear alkylbenzene sulfonate (LAS) is an anionic surfactant widely used to manufacture detergents and found in domestic and industrial wastewater. LAS removal was evaluated in a horizontal anaerobic immobilized biomass reactor. The system was filled with polyurethane foam and inoculated with sludge that was withdrawn from an up flow anaerobic sludge blanket reactor that is used to treat swine wastewater. The reactor was fed with easily degradable substrates and a solution of commercial LAS for 313 days. The hydraulic retention time applied was 12h. The system was initially operated without detergent and resulted to 94% reduction of demand. The mass balance in the system indicated that the LAS removal efficiency was 45% after 18 0days. From the 109 th day to the 254 th day, a removal efficiency of 32% was observed. The removal of LAS was approximately 40% when 1500 mg of LAS were applied in the absence of co-substrates suggesting that the LAS molecules were used selectively. Microscopic analyses of the biofilm revealed diverse microbial morphologies and denaturing gradient gel electrophoresis profiling showed variations in the total bacteria and sulfate-reducing bacteria populations. 16S rRNA sequencing and phylogenetic analyses demonstrated that members of the order Clostridiales were the major components of the bacterial community in the last step of the reactor operation.

  19. A new model for anaerobic processes of up-flow anaerobic sludge blanket reactors based on cellular automata

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Ahring, Birgitte Kiær

    2002-01-01

    characteristics and lead to different reactor behaviour. A dynamic mathematical model has been developed for the anaerobic digestion of a glucose based synthetic wastewater in UASB reactors. Cellular automata (CA) theory has been applied to simulate the granule development process. The model takes...... into consideration that granule diameter and granule microbial composition are functions of the reactor operational parameters and is capable of predicting the UASB performance and the layer structure of the granules....

  20. Grey water treatment in upflow anaerobic sludge blanket (UASB) reactor at different temperatures.

    Science.gov (United States)

    Elmitwalli, Tarek; Otterpohl, Ralf

    2011-01-01

    The treatment of grey water in two upflow anaerobic sludge blanket (UASB) reactors, operated at different hydraulic retention times (HRTs) and temperatures, was investigated. The first reactor (UASB-A) was operated at ambient temperature (14-25 degrees C) and HRT of 20, 12 and 8 h, while the second reactor (UASB-30) was operated at controlled temperature of 30 degrees C and HRT of 16, 10 and 6 h. The two reactors were fed with grey water from 'Flintenbreite' settlement in Luebeck, Germany. When the grey water was treated in the UASB reactor at 30 degrees C, total chemical oxygen demand (CODt) removal of 52-64% was achieved at HRT between 6 and 16 h, while at lower temperature lower removal (31-41%) was obtained at HRT between 8 and 20 h. Total nitrogen and phosphorous removal in the UASB reactors were limited (22-36 and 10-24%, respectively) at all operational conditions. The results showed that at increasing temperature or decreasing HRT of the reactors, maximum specific methanogenic activity of the sludge in the reactors improved. As the UASB reactor showed a significantly higher COD removal (31-64%) than the septic tank (11-14%) even at low temperature, it is recommended to use UASB reactor instead of septic tank (the most common system) for grey water pre-treatment. Based on the achieved results and due to high peak flow factor, a HRT between 8 and 12 h can be considered the suitable HRT for the UASB reactor treating grey water at temperature 20-30 degrees C, while a HRT of 12-24 h can be applied at temperature lower than 20 degrees C.

  1. Hydrogen production from rice winery wastewater in an upflow anaerobic reactor by using mixed anaerobic cultures

    Energy Technology Data Exchange (ETDEWEB)

    Hanqing Yu; Zhenhu Zhu [University of Science and Technology, Hefei, Anhui (China). School of Chemistry and Materials; Wenrong Hu [Shandong Univ., Jinan (China). School of Resources and Environmental Engineering; Haisheng Zhang [Jingzi Wine Distillery Company, Shandong (China)

    2002-12-01

    Continuous production of hydrogen from the anaerobic acidogenesis of a high-strength rice winery wastewater by a mixed bacterial flora was demonstrated. The experiment was conducted in a 3.0-l upflow reactor to investigate individual effects of hydraulic retention time (HRT) (2-24 h), chemical oxygen demand (COD) concentration in wastewater (14-36 g COD/l), pH (4.5-6.0) and temperature (20-55{sup o}C) on bio-hydrogen production from the wastewater. The biogas produced under all test conditions was composed of mostly hydrogen (53-61%) and carbon dioxide (37-45%), but contained no detectable methane. Specific hydrogen production rate increased with wastewater concentration and temperature, but with a decrease in HRT. An optimum hydrogen production rate of 9.33 lH{sub 2}/gVSSd was achieved at an HRT of 2 h, COD of 34 g/l, pH 5.5 and 55{sup o}C. The hydrogen yield was in the range of 1.37-2.14 mol/mol-hexose. In addition to acetate, propionate and butyrate, ethanol was also present in the effluent as an aqueous product. The distribution of these compounds in the effluent was more sensitive to wastewater concentration, pH and temperature, but was less sensitive to HRT. This upflow reactor was shown to be a promising biosystem for hydrogen production from high-strength wastewaters by mixed anaerobic cultures. (Author)

  2. Anaerobic mesophilic treatment of cattle manure in an upflow anaerobic sludge blanket reactor with prior pasteurization.

    Science.gov (United States)

    Marañón, Elena; Castrillón, Leonor; Fernández, Juan José; Fernández, Yolanda; Peláez, Ana Isabel; Sánchez, Jesús

    2006-02-01

    Different autonomous communities located in northern Spain have large populations of dairy cattle. In the case of Asturias, the greatest concentration of dairy farms is found in the areas near the coast, where the elimination of cattle manure by means of its use as a fertilizer may lead to environmental problems. The aim of the present research work was to study the anaerobic treatment of the liquid fraction of cattle manure at mesophilic temperature using an upflow anaerobic sludge blanket (UASB) reactor combined with a settler after a pasteurization process at 70 degrees C for 2 hr. The manure used in this study came from two different farms, with 40 and 200 cows, respectively. The manure from the smaller farm was pretreated in the laboratory by filtration through a 1-mm mesh, and the manure from the other farm was pretreated on the farm by filtration through a separator screw press (0.5-mm mesh). The pasteurization process removed the pathogenic microorganisms lacking spores, such as Enterococcus, Yersinia, Pseudomonas, and coliforms, but bacterial spores are only reduced by this treatment, not removed. The combination of a UASB reactor and a settler proved to be effective for the treatment of cattle manure. In spite of the variation in the organic loading rate and total solids in the influent during the experiment, the chemical oxygen demand (COD) of the effluent from the settler remained relatively constant, obtaining reductions in the COD of approximately 85%.

  3. Microbial community analysis of anaerobic reactors treating soft drink wastewater.

    Directory of Open Access Journals (Sweden)

    Takashi Narihiro

    Full Text Available The anaerobic packed-bed (AP and hybrid packed-bed (HP reactors containing methanogenic microbial consortia were applied to treat synthetic soft drink wastewater, which contains polyethylene glycol (PEG and fructose as the primary constituents. The AP and HP reactors achieved high COD removal efficiency (>95% after 80 and 33 days of the operation, respectively, and operated stably over 2 years. 16S rRNA gene pyrotag analyses on a total of 25 biofilm samples generated 98,057 reads, which were clustered into 2,882 operational taxonomic units (OTUs. Both AP and HP communities were predominated by Bacteroidetes, Chloroflexi, Firmicutes, and candidate phylum KSB3 that may degrade organic compound in wastewater treatment processes. Other OTUs related to uncharacterized Geobacter and Spirochaetes clades and candidate phylum GN04 were also detected at high abundance; however, their relationship to wastewater treatment has remained unclear. In particular, KSB3, GN04, Bacteroidetes, and Chloroflexi are consistently associated with the organic loading rate (OLR increase to 1.5 g COD/L-d. Interestingly, KSB3 and GN04 dramatically decrease in both reactors after further OLR increase to 2.0 g COD/L-d. These results indicate that OLR strongly influences microbial community composition. This suggests that specific uncultivated taxa may take central roles in COD removal from soft drink wastewater depending on OLR.

  4. Sterilization of swine wastewater treated by anaerobic reactors using UV photo-reactors

    Directory of Open Access Journals (Sweden)

    Erlon Lopes Pereira

    2014-09-01

    Full Text Available The use of ultraviolet radiation is an established procedure with growing application forthe disinfection of contaminated wastewater. This study aimed to evaluate the efficiency of artificial UV radiation, as a post treatment of liquid from anaerobic reactors treating swine effluent. The UV reactors were employed to sterilize pathogenic microorganisms. To this end, two photo-reactors were constructed using PVC pipe with100 mm diameter and 1060 mmlength, whose ends were sealed with PVC caps. The photo-reactors were designed to act on the liquid surface, as the lamp does not get into contact with the liquid. To increase the efficiency of UV radiation, photo-reactors were coated with aluminum foil. The lamp used in the reactors was germicidal fluorescent, with band wavelength of 230 nm, power of 30 Watts and manufactured by Techlux. In this research, the HRT with the highest removal efficiency was 0.063 days (90.6 minutes, even treating an effluent with veryhigh turbidity due to dissolved solids. It was concluded that the sterilization method using UV has proved to be an effective and appropriate process, among many other procedures.

  5. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis.

    Science.gov (United States)

    Cai, Weiwei; Han, Tingting; Guo, Zechong; Varrone, Cristiano; Wang, Aijie; Liu, Wenzong

    2016-05-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070 mL CH4/mL reactor/day, which is 2.59 times higher than AD control reactor (0.027 m(3) CH4/m(3)/d). And COD removal is increased ∼15% over AD control. When changing to sludge fermentation liquid, methane production rate has been further increased to 0.247 mL CH4/mL reactor/day (increased by 51.53% comparing with AD control). Energy recovery efficiency presents profitable gains, and economic revenue from increased methane totally self-cover the cost of input electricity. The study indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid.

  6. Strategies for changing temperature from mesophilic to thermophilic conditions in anaerobic CSTR reactors treating sewage sludge.

    Science.gov (United States)

    Bousková, A; Dohányos, M; Schmidt, J E; Angelidaki, I

    2005-04-01

    Thermophilic anaerobic digestion presents an advantageous way for stabilization of sludge from wastewater treatment plants. Two different strategies for changing operational process temperature from mesophilic (37 degrees C) to thermophilic (55 degrees C) were tested using two continuous flow stirred tank reactors operated at constant organic loading rate of 1.38 g VS/l reactor/day and hydraulic retention time of 20 days. In reactor A, the temperature was increased step-wise: 37 degrees C-->42 degrees C-->47 degrees C-->51 degrees C-->55 degrees C. While in reactor B, the temperature was changed in one-step, from 37 degrees C to the desired temperature of 55 degrees C, The results showed that the overall adaptation of the process for the step-wise temperature increment took 70 days in total and a new change was applied when the process was stabilized as indicated by stable methane production and low volatile fatty acids concentrations. Although the one-step temperature increase caused a severe disturbance in all the process parameters, the system reached a new stable operation after only 30 days indicating that this strategy is the best in changing from mesophilic to thermophilic operation in anaerobic digestion plants.

  7. Reator compartimentado anaeróbio/aeróbio: sistema de baixo custo para tratamento de esgotos de pequenas comunidades Anaerobic/aerobic baffled reactor: low cost system for sewage treatment in small communities

    Directory of Open Access Journals (Sweden)

    Gustavo H. R. da Silva

    2005-06-01

    Full Text Available No Brasil são conhecidas e usadas várias técnicas de tratamento de esgoto, desde os mais sofisticados sistemas de tratamento aos mais simples processos. Uma alternativa economicamente viável aos sistemas de tratamento de esgotos sanitários é o processo anaeróbio, o qual tem recebido especial atenção nas pesquisas desenvolvidas no País, notadamente os reatores anaeróbios de alta taxa, unidades compactas e com boa eficiência de tratamento. Dentre as alternativas tecnológicas capazes de proporcionar as referidas variações das condições ambientais necessárias à ocorrência dos processos, está o uso de reatores compartimentados anaeróbio/aeróbio. Este trabalho apresenta, como alternativa, um reator compartimentado anaeróbio/aeróbio, tratando esgoto sanitário, como possibilidade de ser utilizado em pequenas comunidades urbanas e rurais. O desempenho do sistema foi avaliado em diversos tempos de detenção hidráulica (TDH, nos quais os melhores valores de Demanda Química de Oxigênio Total (DQOtotal - 73,7% e Sólidos em Suspensão Totais (SST - 78,8%, foram obtidos com TDHtotal de 8 horas (4 horas para a fase anaeróbia e 4 horas para a fase aeróbia. O reator compartimentado apresentou a característica de estabilidade operacional necessária aos sistemas de baixo custo.Several techniques of sewage treatment, from the most sophisticated to the simplest processes, are known in Brazil. An economically viable alternative for the systems of treatment of sanitary sewage is the anaerobic process, which has been given special attention in Brazilian research programs, mainly in the field of high rate anaerobic reactors as they are compact units and have high efficiency. The use of baffled anaerobic/aerobic reactors is one technological solution to provide the necessary variations in environmental conditions to foster the processes mentioned. In this paper an alternative is presented in the form of a baffled anaerobic

  8. Anaerobic biofilm reactors for dark fermentative hydrogen production from wastewater: A review.

    Science.gov (United States)

    Barca, Cristian; Soric, Audrey; Ranava, David; Giudici-Orticoni, Marie-Thérèse; Ferrasse, Jean-Henry

    2015-06-01

    Dark fermentation is a bioprocess driven by anaerobic bacteria that can produce hydrogen (H2) from organic waste and wastewater. This review analyses a relevant number of recent studies that have investigated dark fermentative H2 production from wastewater using two different types of anaerobic biofilm reactors: anaerobic packed bed reactor (APBR) and anaerobic fluidized bed reactor (AFBR). The effect of various parameters, including temperature, pH, carrier material, inoculum pretreatment, hydraulic retention time, substrate type and concentration, on reactor performances was investigated by a critical discussion of the results published in the literature. Also, this review presents an in-depth study on the influence of the main operating parameters on the metabolic pathways. The aim of this review is to provide to researchers and practitioners in the field of H2 production key elements for the best operation of the reactors. Finally, some perspectives and technical challenges to improve H2 production were proposed.

  9. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    Science.gov (United States)

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-04-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment.

  10. Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiaofeng; Zhu, Shuangyan; Zhong, Delai; Zhu, Jingping, E-mail: jpzhuhust@163.com; Liao, Li, E-mail: liaoli2003@126.com

    2014-11-15

    Highlights: • Anaerobic co-digestion strategy for food waste treatment at OLR 41.8 g VS/L. • A certain amount of raw leachate effectively relieved acidic inhibition. • The study showed that food waste was completely degraded. - Abstract: In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH{sub 4}–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded. We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production.

  11. Experiences with anaerobic treatment of fat-containing food waste liquids: two full scale studies with a novel anaerobic flotation reactor.

    Science.gov (United States)

    Frijters, C T M J; Jorna, T; Hesselink, G; Kruit, J; van Schaick, D; van der Arend, R

    2014-01-01

    Fat-containing food waste can be effectively treated in a new type of reactor, the so-called BIOPAQ-Anaerobic Flotation Reactor or BIOPAQ(®) anaerobic flotation reactor (AFR). In the reactor a flotation unit is integrated to retain the sludge. In this study results from two plants with a 430 and 511 m(3)-AFR, respectively, are presented. In one reactor, which is fed with water originating from different food liquid streams, over 99% of fat and oils were removed. Over 90% of the chemical oxygen demand (COD) was removed. When the last solids were removed from the effluent with a tilted plate settler, 98% COD removal was attained. The effluent concentrations of extractable hydrolysed and non-hydrolysed fats were less than 40 mg/l. Apparently the variations in the liquid streams deriving from the tank cleaning activities did not disturb the system. Only extremely high concentrations of fats could disturb the system, but the inhibition was reversible. In the reactor treating water from an ice-cream factory, which contained fats up to approximately 50% of influent COD, a COD removal efficiency of 90% was achieved. At volumetric loading rates varying from 1 to 8 kg COD/m(3)/d, biogas was produced at an average specific gas production of 0.69 m(3)/kg COD-removed.

  12. Performance comparison between mesophilic and thermophilic anaerobic reactors for treatment of palm oil mill effluent.

    Science.gov (United States)

    Jeong, Joo-Young; Son, Sung-Min; Pyon, Jun-Hyeon; Park, Joo-Yang

    2014-08-01

    The anaerobic digestion of palm oil mill effluent (POME) was carried out under mesophilic (37°C) and thermophilic (55°C) conditions without long-time POME storage in order to compare the performance of each condition in the field of Sumatra Island, Indonesia. The anaerobic treatment system was composed of anaerobic hybrid reactor and anaerobic baffled filter. Raw POME was pretreated by screw decanter to reduce suspended solids and residual oil. The total COD removal rate of 90-95% was achieved in both conditions at the OLR of 15kg[COD]/m(3)/d. The COD removal in thermophilic conditions was slightly better, however the biogas production was much higher than that in the mesophilic one at high OLR. The organic contents in pretreated POME were highly biodegradable in mesophilic under the lower OLRs. The biogas production was 13.5-20.0l/d at the 15kg[COD]/m(3)/d OLR, and the average content of carbon dioxide was 5-35% in both conditions.

  13. [Treatment of landfill leachate using sequential anaerobic/aerobic moving-bed biofilm reactor].

    Science.gov (United States)

    Chen, Sheng; Sun, De-zhi; Chen, Gui-xia; Jong, Shik Chung

    2006-10-01

    A sequential anaerobic-aerobic moving-bed biofilm reactor (MBBR) was employed to treat landfill leachate produced from disposal of municipal solid waste. The affecting operation conditions were investigated, and the affecting mechanism was also analyzed. The results showed that the HRT and organic loading rate (OLR) could greatly influence the treat efficiency. When the influent OLR was in the range of 4.01 - 7.87 kg/(m3 x d), the average total COD removal efficiency was 94.2%, and the contribution of anaerobic stage to total COD removal efficiency was 87.95% - 92.76%; while the influent OLR was in the range of 10.23-16.14 kg/(m3 x d), the average total COD removal efficiency was still 92.64%, and the contribution of anaerobic stage to total COD removal efficiency was 79.05% - 86.56%. As long as HRT of aerobic MBBR was longer than 1.25 d, the total HN4+ -N removal efficiency was persistently more than 97%; while the HRT was 0.75 d, the total HN4+ -N removal efficiency was only about 20%. The sequential anaerobic-aerobic MBBR can endure strong loading impact, even though the OLR was sharply increased 4 times and lasted for 24 h; the system could recover the normal treat efficiency in 3 d.

  14. Decolorization of Orange Ⅱ using an anaerobic sequencing batch reactor with and without co-substrates

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

    We investigated the decolorization of Orange Ⅱ with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor (ASBR).The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange H-containing wastewater enhanced color removal from 27% to 81% to 89%,respectively.In the absence of co-substrates and nutrients,more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange Ⅱ.The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR,which was important for the reduction of the Orange Ⅱ azo bond that caused decolorization.The maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.

  15. Anaerobic digestion performance of vinegar residue in continuously stirred tank reactor.

    Science.gov (United States)

    Li, Lin; Feng, Lu; Zhang, Ruihong; He, Yanfeng; Wang, Wen; Chen, Chang; Liu, Guangqing

    2015-06-01

    Anaerobic digestion (AD) of vinegar residue was investigated in continuously stirred tank reactor (CSTR). The influence of organic loading rate (OLR) and effluent recirculation on AD performance of vinegar residue was tested. Five OLRs, 1.0, 1.5, 2.0, 2.5, and 3.0 g(vs) L(-1) d(-1), were used. The highest volumetric methane productivity of 581.88 mL L(-1) was achieved at OLR of 2.5 g(vs) L(-1) d(-1). Effluent reflux ratio was set as 50%, the results showed that effluent recirculation could effectively neutralize the acidity of vinegar residue, raise the pH of the feedstock, and enhance the buffering capacity of the AD system. Anaerobic digestion of vinegar residue could be a promising way not only for converting this waste into gas energy but also alleviating environmental pollution which might be useful for future industrial application.

  16. The anaerobic baffled reactor (ABR) treating communal wastewater under mesophilic conditions: a review.

    Science.gov (United States)

    Reynaud, N; Buckley, C A

    2016-01-01

    A review concerning the anaerobic baffled reactor (ABR) treating communal wastewater under mesophilic conditions is presented. Existing studies indicate strong resilience of the reactor towards loading variations and shock-loads. The compartmentalisation of the ABR is a strongly stabilising factor with feed fluctuations being evened out across reactor chambers. Significant chemical oxygen demand (COD) reduction occurs almost exclusively in the first three chambers. The hydraulic rather than the organic loading rate is treatment limiting. Laboratory-scale studies show high treatment efficiencies of above 80% COD removal. It was found that most laboratory-scale studies do not factor in important aspects of field operation, such as diurnal fluctuations of feed characteristics, adequate start-up periods and periods of constant loading and optimised chamber outlet design, and never studied the effect of loading on sludge digestion. Performance data on full-scale ABR implementations, however, are extremely scarce, and existing studies are without exception affected by site-specific treatment-limiting factors hindering the extrapolation of generally valid conclusions. In view of a large-scale roll-out, communal ABRs are not sufficiently understood. Current challenges concerning the optimisation of reactor design require numerous well-monitored long-term full-scale reactor investigations. Existing ABR investigations yield encouraging results, supporting that the ABR may be one of the solutions answering the global call for low-maintenance, robust treatment systems.

  17. Application of Box-Wilson experimental design method for 2,4-dinitrotoluene treatment in a sequential anaerobic migrating blanket reactor (AMBR)/aerobic completely stirred tank reactor (CSTR) system.

    Science.gov (United States)

    Kuşçu, Özlem Selçuk; Sponza, Delia Teresa

    2011-03-15

    A sequential aerobic completely stirred tank reactor (CSTR) following the anaerobic migrating blanket reactor (AMBR) was used to treat a synthetic wastewater containing 2,4-dinitrotoluene (2,4-DNT). A Box-Wilson statistical experiment design was used to determine the effects of 2,4-DNT and the hydraulic retention times (HRTs) on 2,4-DNT and COD removal efficiencies in the AMBR reactor. The 2,4-DNT concentrations in the feed (0-280 mg/L) and the HRT (0.5-10 days) were considered as the independent variables while the 2,4-DNT and chemical oxygen demand (COD) removal efficiencies, total and methane gas productions, methane gas percentage, pH, total volatile fatty acid (TVFA) and total volatile fatty acid/bicarbonate alkalinity (TVFA/Bic.Alk.) ratio were considered as the objective functions in the Box-Wilson statistical experiment design in the AMBR. The predicted data for the parameters given above were determined from the response functions by regression analysis of the experimental data and exhibited excellent agreement with the experimental results. The optimum HRT which gave the maximum COD (97.00%) and 2,4-DNT removal (99.90%) efficiencies was between 5 and 10 days at influent 2,4-DNT concentrations 1-280 mg/L in the AMBR. The aerobic CSTR was used for removals of residual COD remaining from the AMBR, and for metabolites of 2,4-DNT. The maximum COD removal efficiency was 99% at an HRT of 1.89 days at a 2,4-DNT concentration of 239 mg/L in the aerobic CSTR. It was found that 280 mg/L 2,4-DNT transformed to 2,4-diaminotoluene (2,4-DAT) via 2-amino-4-nitrotoluene (2-A-4-NT) and 4-amino-2-nitrotoluene (4-A-2-NT) in the AMBR. The maximum 2,4-DAT removal was 82% at an HRT of 8.61 days in the aerobic CSTR. The maximum total COD and 2,4-DNT removal efficiencies were 99.00% and 99.99%, respectively, at an influent 2,4-DNT concentration of 239 mg/L and at 1.89 days of HRT in the sequential AMBR/CSTR.

  18. Design of Upelow Anaerobic Sludge Blanket reactor for treatment of organic wastewaters.

    Science.gov (United States)

    Ghangrekar, M M; Kahalekar, U J; Takalkar, S V

    2003-04-01

    The Upflow Anaerobic Sludge Blanket (UASB) Reactor is widely applied anaerobic wastewater treatment method all over the world. Uniform distribution of wastewater at reactor bottom is necessary to establish proper contact between sludge and wastewater. In addition, proper functioning of Gas-Liquid-Solid (GLS) separator is crucial to ensure maximum sludge retention in the reactor and to achieve maximum COD removal rate in the reactor. Hence, proper design of reactor is necessary for appropriate functioning of various components for a given wastewater flow rate and COD concentration. The design procedure for UASB reactor taking due consideration to the GLS design and design of inlet arrangement is discussed in this paper for various wastewater strength and flow rates. A software is developed to make economical design of UASB reactor for different type of wastewater by adopting maximum loading conditions, based on literature recommendations, and at the same time to satisfy all design recommendation, as far as possible.

  19. Stability of anaerobic reactors under micro-aeration conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Polanco, M.; Perez, S.; Diaz, I.; Fernandez-Polanco, F.

    2009-07-01

    Oxidation of sulphide in anaerobic bioreactors by introducing limited amounts of oxygen provides a relatively simple strategy for reducing the levels of sulphite in anaerobic digesters (biogas and effluent). The introduction of limited amounts of air is a general practice in agricultural anaerobic digesters, it is estimated that worldwide over 3.000 units are operated under such conditions. (Author)

  20. Start up of an anaerobic inverse turbulent bed reactor fed with wine distillery wastewater using pre-colonised bioparticles.

    Science.gov (United States)

    Amaiz, C; Elmaleh, S; Lebrato, J; Moletta, R

    2005-01-01

    The long start-up period of fluidized bed biofilm reactors is a serious obstacle for their wide installation in the anaerobic treatment of industrial wastewater. This paper presents the results of an anaerobic inverse turbulent bioreactor treating distillery wastewater during 117 days of operation at a laboratory scale. The pre-colonized bioparticles for this work were obtained from a similar reactor processing the same wastewater and which had a start-up period of 3 months. The system attained carbon removal efficiency rates between 70 and 92%, at an organic loading rate of 30.6 kg m(-3) d(-1) (chemical oxygen demand) with a hydraulic retention time of 11.1 h. The results obtained showed that the start-up period of this kind of reactors can be reduced by 3 using pre-colonized bioparticles.

  1. A test study on treatment of high-strength polyester wastewater with anaerobic reactor

    Institute of Scientific and Technical Information of China (English)

    韩洪军; 陈秀荣; 徐春艳

    2002-01-01

    The treatment of polyester wastewater using Up-flow activated sludge bed anaerobic filer ( UASB-AF), demonstrated that UASB-AF reactors has a high efficiency, its volume loading is 10 ~ 12 kgCOD/( m3 @d) ,HRT is 22 ~24 h, and the removal of COD is about 80%. The reactor has advantage of fast starting andenduring pulse loading.

  2. Dispersed plug flow model for upflow anaerobic sludge bed reactors with focus on granular sludge dynamics

    NARCIS (Netherlands)

    Kalyuzhnyi, S.V.; Fedorovich, V.V.; Lens, P.N.L.

    2006-01-01

    A new approach to model upflow anaerobic sludge bed (UASB)-reactors, referred to as a one-dimensional dispersed plug flow model, was developed. This model focusses on the granular sludge dynamics along the reactor height, based on the balance between dispersion, sedimentation and convection using on

  3. 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 perf

  4. On-off and PI Control of Methane Gas Production of a Pilot Anaerobic Digestion Reactor

    Directory of Open Access Journals (Sweden)

    Finn Haugen

    2013-07-01

    Full Text Available A proposed feedback control system for methane flow control of a real pilot anaerobic digestion reactor fed with dairy waste is designed and analyzed using the modified Hill model, which has previously been adapted to the reactor. Conditions for safe operation of the reactor are found using steady-state responses of dynamic simulations, taking into account the upper limit of the volatile fatty acids (VFA concentration recommended in the literature. The controllers used are standard process controllers, namely the on-off controller and the PI controller. Several PI controller tuning methods are evaluated using simulations. Two methods are favoured, namely the Skogestad method, which is an open loop method, and the Relaxed Ziegler-Nichols closed loop method. The two methods give approximately the same PI settings. Still, the Skogestad method is ranged first as it requires less tuning time, and because it is easier to change the PI settings at known changes in the process dynamics. Skogestad's method is successfully applied to a PI control system for the real reactor. Using simulations, the critical operating point to be used for safe controller tuning is identified.

  5. Domestic wastewater anaerobic treatment I : Performance of one-step UASB and HUSB reactors; Tratamiento anaerobio de aguas residuales urbanas I : Aplicacion de reactores UASB y HUSB de etapa unica

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Rodriguez, J. A.; Gomez Lopez, M.; Soto Castineira, M.

    2005-07-01

    Domestic wastewater treatment was carried out on a pilot scale anaerobic digester, with an active volume of 25.5 m''3. The digester operated at different conditions: (a) as an UASB reactor (up-flow anaerobic sludge blanket), with the aim of reaching a complete anaerobic treatment of domestic wastewater, and (b) as a HUSB (hydrolytic upflow sludge blanket) reactor, working in this case as a wastewater pre-treatment that removes suspended solid matter and increase the effluent biodegradability. The advantages of these treatment systems are its economic feasibility, no energy consumption and low excess sludge generation. (Author) 17 refs.

  6. Performance analysis of upflow anaerobic sludge blanket reactors in the treatment of swine wastewater

    Directory of Open Access Journals (Sweden)

    Luiz A. V. Sarmento

    2007-07-01

    Full Text Available The adoption of confined systems for swine production have been increased the use of water in these installations and, consequently, an each time greater production of wastewater. Diagnostics have been showed a high level of water pollution due the waste material release on lands without criterions and in waters without previous treatment. The utilization of anaerobic process to reduce the liquid residues pollutant power has been detaching because beyond reducing the environmental pollution they allow to recover the energetic potential as fertilizer and biogas. In this work the performance of two real scale upflow anaerobic sludge blanket reactors treating swine wastewater were evaluated through operational system analysis, physical-chemical parameters of pollution and biogas production measurement. The results permitted to verify upflow rate speeds above of the value for which these reactors were designed and hydraulic residence times under of the design value. These factors affected negatively the treatment and had reflected on the law removal of the physical-chemical parameters and biogas production. The maximum removal efficiencies reached for TSS, BOD and COD were 72,5%, 34,7% and 40,0%, respectively. The mean rate of biogas liberation was 0,011 m-³ m-².h-1.

  7. Modelling Methane Production and Sulfate Reduction in Anaerobic Granular Sludge Reactor with Ethanol as Electron Donor

    Science.gov (United States)

    Sun, Jing; Dai, Xiaohu; Wang, Qilin; Pan, Yuting; Ni, Bing-Jie

    2016-10-01

    In this work, a mathematical model based on growth kinetics of microorganisms and substrates transportation through biofilms was developed to describe methane production and sulfate reduction with ethanol being a key electron donor. The model was calibrated and validated using experimental data from two case studies conducted in granule-based Upflow Anaerobic Sludge Blanket reactors. The results suggest that the developed model could satisfactorily describe methane and sulfide productions as well as ethanol and sulfate removals in both systems. The modeling results reveal a stratified distribution of methanogenic archaea, sulfate-reducing bacteria and fermentative bacteria in the anaerobic granular sludge and the relative abundances of these microorganisms vary with substrate concentrations. It also indicates sulfate-reducing bacteria can successfully outcompete fermentative bacteria for ethanol utilization when COD/SO42‑ ratio reaches 0.5. Model simulation suggests that an optimal granule diameter for the maximum methane production efficiency can be achieved while the sulfate reduction efficiency is not significantly affected by variation in granule size. It also indicates that the methane production and sulfate reduction can be affected by ethanol and sulfate loading rates, and the microbial community development stage in the reactor, which provided comprehensive insights into the system for its practical operation.

  8. Experimental study of hydrodynamic and operation start of a baffled anaerobic reactor treating sewage

    Directory of Open Access Journals (Sweden)

    Ana Carolina Silveira Perico

    2009-12-01

    Full Text Available It is important to provide individual sanitation systems for sewage peri-urban communities or rural areas to minimize impacts on the environment and human health caused by sewage discharge in natura into water resources. In this context, the anaerobic digestion of effluent has been one of the main considered technologies due to easy implementation, material minimization and reduction in waste production. The objective of this work was to study a Baffled Anaerobic Reactor (BAR including its hydrodynamic characteristics, percentile of inoculum to be applied and reactor operation start. It was concluded that the flow is dispersed with 3.84% of dead spaces and that 20% of the cow manure provided best results; however, due to the high fiber content of the manure, its use is not recommended as inoculum. The BAR system, composed of four chambers, presented good performance for sewage treatment of a rural community in terms of organic substance removal (COD, turbidity and solids meeting effluent disposal standards of these parameters considering the Federal and Minas Gerais State legislation, in Brazil, even in a transient phase of operation, at temperatures below 20°C. However, the effluents from the BAR can’t be released into water bodies without other parameters such as nitrogen, phosphorus, fecal coliforms, and others are investigated to be conforming to those standards.

  9. Hydrodynamical modelling of upflow anaerobic sludge blanket reactors; Modelagem hidrodinamica de reatores anaerobios de escoamento ascendente e manta de lodo (UASB)

    Energy Technology Data Exchange (ETDEWEB)

    Hanisch, Werner Siegfried

    1995-12-31

    The increasing need to treat wastewater consuming a minimum amount of energy is a clear indication of the appropriateness of anaerobic processes. One of them, the upflow anaerobic sludge blanket reactor (UASB), has shown to be a feasible option to treat industrial wastewater and domestic sewage. To improve this treatment system the knowledge if of its hydrodynamic behaviour is fundamental. In this work a mathematical model is proposed to describe physical simulations that were performed in bench scale UASB reactors. The results allow to conclude that the proposed mathematical model is adequate to describe the hydrodynamical behaviour of the above mentioned reactors 27 refs., 78 figs., 12 tabs.

  10. State Estimation and Model-Based Control of a Pilot Anaerobic Digestion Reactor

    Directory of Open Access Journals (Sweden)

    Finn Haugen

    2014-01-01

    Full Text Available A state estimator and various model-based control systems have been designed for a real anaerobic digestion (AD pilot reactor fed with dairy manure. The model used is a modified Hill model which is a relatively simple dynamical AD process model. The state estimator is an Unscented Kalman Filter (UKF which uses only methane gas flow measurement to update its states. The model and the state estimates are used in different control systems. One of the control systems aims at controlling the methane gas flow to a setpoint. Simulations indicate that the setpoint tracking performance of a predictive control system is considerably better comparing with PI control, while disturbance compensation is not much better. Consequently, assuming the setpoint is constant, the PI controller competes well with the predictive controller. A successful application of predictive control of the real reactor is presented. Also, three different control systems aiming at retaining the reactor at an operating point where the volatile fatty acids (VFA concentration has a maximum, safe value are designed. A simulation study indicates that the best control solution among the three alternatives is PI control based on feedback from estimated VFA.

  11. Anaerobic degradation of landfill leachate using an upflow anaerobic fixed-bed reactor with microbial sulfate reduction.

    Science.gov (United States)

    Thabet, Olfa Ben Dhia; Bouallagui, Hassib; Cayol, Jean-luc; Ollivier, Bernard; Fardeau, Marie-Laure; Hamdi, Moktar

    2009-08-15

    This study evaluated the anaerobic degradation of landfill leachate and sulfate reduction as a function of COD/(SO(4)(2-)) ratio in an upflow anaerobic fixed-bed reactor. The reactor, which was inoculated with a mixed consortium, was operated under a constant hydraulic retention time (HRT) of 5 days. We investigated the effect of COD/(SO(4)(2-)) ratio variation on the sulfate reduction efficiency, hydrogen sulfide production, chemical oxygen demand (COD) removal, conductivity, and pH variation. The best reactor performance, with significant sulfate reduction efficiency and COD removal efficiency of 91% and 87%, respectively, was reached under a COD/(SO(4)(2-)) ratio of 1.17. Under these conditions, microscopic analysis showed the abundance of vibrios and rod-shaped bacterial cells. Two anaerobic bacteria were isolated from the reactor sludge. Phylogenetic studies performed on these strains identified strain A1 as affiliated to Clostridium genus and strain H1 as a new species of sulfate-reducing bacteria affiliated to the Desulfovibrio genus. The closest phylogenetic relative of strain H1 was Desulfovibrio desulfuricans, at 96% similarity for partial 16S RNA gene sequence data. Physiological and metabolic characterization was performed for this strain.

  12. Anaerobic treatment of a chemical synthesis-based pharmaceutical wastewater in a hybrid upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Oktem, Yalcin Askin; Ince, Orhan; Sallis, Paul; Donnelly, Tom; Ince, Bahar Kasapgil

    2008-03-01

    In this study, performance of a lab-scale hybrid up-flow anaerobic sludge blanket (UASB) reactor, treating a chemical synthesis-based pharmaceutical wastewater, was evaluated under different operating conditions. This study consisted of two experimental stages: first, acclimation to the pharmaceutical wastewater and second, determination of maximum loading capacity of the hybrid UASB reactor. Initially, the carbon source in the reactor feed came entirely from glucose, applied at an organic loading rate (OLR) 1 kg COD/m(3) d. The OLR was gradually step increased to 3 kg COD/m(3) d at which point the feed to the hybrid UASB reactor was progressively modified by introducing the pharmaceutical wastewater in blends with glucose, so that the wastewater contributed approximately 10%, 30%, 70%, and ultimately, 100% of the carbon (COD) to be treated. At the acclimation OLR of 3 kg COD/m(3) d the hydraulic retention time (HRT) was 2 days. During this period of feed modification, the COD removal efficiencies of the anaerobic reactor were 99%, 96%, 91% and 85%, and specific methanogenic activities (SMA) were measured as 240, 230, 205 and 231 ml CH(4)/g TVS d, respectively. Following the acclimation period, the hybrid UASB reactor was fed with 100% (w/v) pharmaceutical wastewater up to an OLR of 9 kg COD/m(3) d in order to determine the maximum loading capacity achievable before reactor failure. At this OLR, the COD removal efficiency was 28%, and the SMA was measured as 170 ml CH(4)/g TVS d. The hybrid UASB reactor was found to be far more effective at an OLR of 8 kg COD/m(3) d with a COD removal efficiency of 72%. At this point, SMA value was 200 ml CH(4)/g TVS d. It was concluded that the hybrid UASB reactor could be a suitable alternative for the treatment of chemical synthesis-based pharmaceutical wastewater.

  13. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Rahayu, Suparni Setyowati, E-mail: suparnirahayu@yahoo.co.id [Doctoral Program in Environmental Science, University of Diponegoro, Semarang (Indonesia); Department of Mechanical Engineering, State Polytechnic of Semarang, Semarang Indonesia (Indonesia); Purwanto,, E-mail: p.purwanto@che.undip.ac.id; Budiyono, E-mail: budiyono@live.undip.ac.id [Doctoral Program in Environmental Science, University of Diponegoro, Semarang (Indonesia); Department of Chemical Engineering, Faculty of Engineering, Diponegoro University, Semarang Indonesia (Indonesia)

    2015-12-29

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH{sub 4}/g COD and produce biogas containing of CH{sub 4}: 81.23% and CO{sub 2}: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature.

  14. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    Science.gov (United States)

    Rahayu, Suparni Setyowati; Purwanto, Budiyono

    2015-12-01

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH4/g COD and produce biogas containing of CH4: 81.23% and CO2: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature.

  15. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  16. Biohydrogen production from diary processing wastewater by anaerobic biofilm reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rios-Gonzalez, L.J.; Moreno-Davila, I.M.; Rodriguez-Martinez, J.; Garza-Garcia, Y. [Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico)]. E-mail: leopoldo.rios@mail.uadec.mx

    2009-09-15

    This article describes biological hydrogen production from diary wastewater via anaerobic fermentation using pretreated heat shock (100 degrees Celsius, 30 min.) and acid (pH 3.0, 24 h) treatment procedures to selectively enrich the hydrogen producing mixed consortia prior to inoculation to batch reactors. Bioreactor used for immobilization consortia was operated at mesophilic (room) temperature (20{+-}3 degrees Celsius), under acidophilic conditions (pH 4.0-4.5), HRT (2h), and a natural support for generate hydrogen producing mixed consortia biofilm: Opuntia imbricata. Reactor was initially operated with sorbitol (5g/L) for 60 days of operation. Batch tests were conducted using 20{+-}0.02g of natural support with biofilm. Batch experiments were conducted to investigate the effect of COD (2.9-21.1 g-COD/L), at initial pH of 7.0, 32{+-}1 degrees Celsius. Maximum hydrogen yield was obtained at 21.1 g-COD/L. Experiments of pH effect were conducted using the optimal substrate concentration (21.2 g-COD/L), at pH 4 to 7 and 11.32 (pH diary wastewater) ,and 32{+-}1 degrees Celsius. Experiments results indicate the optimum initial cultivation was pH 4.0, but we can consider also a stable hydrogen production at pH 11.32 (pH diary wastewater), so we can avoid to fit the pH, and use diary wastewater as it left the process of cheese manufacture. The operational pH of 4.0 is 1.5 units below that of previously reported hydrogen producing organisms. The influence of the effect of temperature were conducted using the optimal substrate concentration (21.2 g-COD/L), two pH levels: 4.0 and 11.32, and four different temperatures: 16{+-}3 degrees Celsius (room temperature), 3 C, 45{+-}1 degrees Celsius y 55{+-}1 degrees Celsius.Optimal temperature for hydrogen production from diary wastewater at pH 4.0 was 55{+-}1 degrees Celsius, and for pH 11.32 was 16{+-}3 degrees Celsius.Therefore, the results suggests biofilm reactors in a natural support like Opuntia imbricata have good potential

  17. Evaluation of reactor anaerobic sludge blanket in the treatment of wastewater slaughterhouse

    Directory of Open Access Journals (Sweden)

    Luciano dos Santos Rodrigues

    2014-10-01

    Full Text Available This study aimed to evaluate the efficiency of a full-scale treatment system effluent slaughterhouse. The full-scale Sewage Treatment Station was designed for a daily flow of 60 m³/d, corresponding to a slaughter of 60 cattle per day. The treatment system consists of a Parshall flume for flow measurement, followed by static sieve, gravimetric fat, sedimentation and anaerobic sludge blanket (UASB box and it was monitored weekly from January to August. The following parameters were analyzed: pH, alkalinity, biochemical oxygen demand (BOD, chemical oxygen demand (COD, total solids (TS, total suspended solids (TSS, ammonia nitrogen, and total nitrogen kjedhall. The average pH, COD and TSS in the UASB reactor effluent values were 6.96, 660 mg/L and 188 mg/L , respectively. The system proved to be efficient, with average removal of 96.40% to 89.92% for COD and TSS. The UASB reactor showed high performance in removing solids and organic load. Thus, this reactor becomes a viable alternative for treating wastewater slaughterhouse, offering good removal results and low cost of deployment.

  18. Feasibility of hydraulic separation in a novel anaerobic-anoxic upflow reactor for biological nutrient removal.

    Science.gov (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Volcke, Eveline I P; Tejero, Iñaki

    2015-01-01

    This contribution deals with a novel anaerobic-anoxic reactor for biological nutrient removal (BNR) from wastewater, termed AnoxAn. In the AnoxAn reactor, the anaerobic and anoxic zones for phosphate removal and denitrification are integrated in a single continuous upflow sludge blanket reactor, aiming at high compactness and efficiency. Its application is envisaged in those cases where retrofitting of existing wastewater treatment plants for BNR, or the construction of new ones, is limited by the available surface area. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. The capability of the AnoxAn configuration to establish two hydraulically separated zones inside the single reactor was assessed by means of hydraulic characterization experiments and model simulations. Residence time distribution (RTD) experiments in clean water were performed in a bench-scale (48.4 L) AnoxAn prototype. The required hydraulic separation between the anaerobic and anoxic zones, as well as adequate mixing in the individual zones, were obtained through selected mixing devices. The observed behaviour was described by a hydraulic model consisting of continuous stirred tank reactors and plug-flow reactors. The impact of the denitrification process in the anoxic zone on the hydraulic separation was subsequently evaluated through model simulations. The desired hydraulic behaviour proved feasible, involving little mixing between the anaerobic and anoxic zones (mixing flowrate 40.2 % of influent flowrate) and negligible nitrate concentration in the anaerobic zone (less than 0.1 mgN L(-1)) when denitrification was considered.

  19. Metal concentrations of simulated aerobic and anaerobic pilot scale landfill reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sinan Bilgili, M. [Yildiz Technical University, Environmental Engineering Department, 34349 Yildiz, Besiktas, Istanbul (Turkey)]. E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Yildiz, Besiktas, Istanbul (Turkey)]. E-mail: ahmetd@yildiz.edu.tr; Ince, Mahir [Department of Environmental Engineering, Gebze Institute of Technology, 41400 Gebze (Turkey)]. E-mail: mahirince@gyte.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Yildiz, Besiktas, Istanbul (Turkey)]. E-mail: bozkaya@yildiz.edu.tr

    2007-06-25

    Leachate and solid waste samples from aerobic and anaerobic simulated landfill reactors operated with and without leachate recirculation were characterized in terms of metals such as Fe, Ca, K, Na, Cd, Cr, Cu, Pb, Ni, and Zn. Metal concentrations of aerobic landfill reactor leachate samples are always below the regulation limits. The higher concentrations in anaerobic landfill leachate samples decreased to regulation limits after the landfill becomes methanogenic. The effect of leachate recirculation is determined in anaerobic landfills more clearly than aerobic landfills. Metal precipitation resulted in a decrease in leachate metal content and an increase in solid waste metal content as expected. Result of the study show that the metal content of landfill leachate samples is not a major concern for both aerobic and anaerobic landfills.

  20. Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2012-01-01

    the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO2 to CH4...... by PCR–DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree......Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO2, biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using...

  1. Central treatment of different emulsion wastewaters by an integrated process of physicochemically enhanced ultrafiltration and anaerobic-aerobic biofilm reactor.

    Science.gov (United States)

    Zhang, Weijun; Xiao, Ping; Wang, Dongsheng

    2014-05-01

    The feasibility of an integrated process of ultrafiltration (UF) enhanced by combined chemical emulsion breaking with vibratory shear and anaerobic/aerobic biofilm reactor for central treatment of different emulsion wastewaters was investigated. Firstly, it was found that calcium chloride exhibited better performance in oil removal than other inorganic salts. Chemical demulsification pretreatment could efficiently improve oil removal and membrane filtration in emulsion wastewater treatment by VSEP. According to aerobic batch bioassay, UF permeate exhibited good biodegradability and could be further treated with biological process. Additionally, pilot test indicated that anaerobic-aerobic biofilm exhibited an excellent ability against rise in organic loading and overall chemical oxygen demand (COD) removal efficiency of biological system was more than 93% of which 82% corresponded to the anaerobic process and 11% to the aerobic degradation. The final effluent of integrated process could meet the "water quality standards for discharge to municipal sewers" in China.

  2. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    Science.gov (United States)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  3. Effects of ferric iron on the anaerobic treatment and microbial biodiversity in a coupled microbial electrolysis cell (MEC)--anaerobic reactor.

    Science.gov (United States)

    Zhang, Jingxin; Zhang, Yaobin; Quan, Xie; Chen, Shuo

    2013-10-01

    Adding Fe(III) into a MEC - anaerobic reactor enhanced the degradation of organic matters. To clarify the respective effects of combining Fe(III) dosage and a MEC and Fe(III) dosage only on strengthening anaerobic digestion, three anaerobic reactors were operated in parallel: a MEC - anaerobic reactor with dosing Fe(OH)3 (R1), an anaerobic reactor with dosing Fe(OH)3 (R2) and a common anaerobic reactor (R3). With increasing influent COD from 1500 to 4000 mg/L, the COD removal in R1 was maintained at 88.3% under a voltage of 0.8 V, which was higher than that in reactor R2 and R3. When the power was cut off, the COD removal in R1 decreased by 5.9%. The addition of Fe(OH)3 enhanced both anaerobic digestion and anodic oxidation, resulting in the effective mineralization of volatile fatty acids (VFAs). The reduced Fe(II) combined with electric field resulted more extracellular polymeric substances (EPS) production. Quantitative real - time PCR showed a higher abundance of bacteria in the anodic biofilm and R1. Pyrosequencing and denaturing gradient gel electrophoresis (DGGE) analysis revealed that the dominant bacteria and archaea communities were richer and more abundant in the anode biofilm and R1.

  4. Enhanced decolorization of azo dye in a small pilot-scale anaerobic baffled reactor coupled with biocatalyzed electrolysis system (ABR-BES): a design suitable for scaling-up.

    Science.gov (United States)

    Cui, Dan; Guo, Yu-Qi; Lee, Hyung-Sool; Wu, Wei-Min; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2014-07-01

    A four-compartment anaerobic baffled reactor (ABR) incorporated with membrane-less biocatalyzed electrolysis system (BES) was tested for the treatment of azo dye (alizarin yellow R, AYR) wastewater (AYR, 200 mg L(-1); glucose, 1000 mg L(-1)). The ABR-BES was operated without and with external power supply to examine AYR reduction process and reductive intermediates with different external voltages (0.3, 0.5 and 0.7 V) and hydraulic retention times (HRT: 8, 6 and 4h). The decolorization efficiency in the ABR-BES (8h HRT, 0.5 V) was higher than that in ABR-BES without electrolysis, i.e. 95.1 ± 1.5% versus 86.9 ± 6.3%. Incorporation of BES with ABR accelerated the consumption of VFAs (mainly acetate) and attenuated biogas (methane) production. Higher power supply (0.7 V) enhanced AYR decolorization efficiency (96.4 ± 1.8%), VFAs removal, and current density (24.1 Am(-3) TCV). Shorter HRT increased volumetric AYR decolorization rates, but decreased AYR decolorization efficiency.

  5. A novel fast mass transfer anaerobic inner loop fluidized bed biofilm reactor for PTA wastewater treatment.

    Science.gov (United States)

    Chen, Yingwen; Zhao, Jinlong; Li, Kai; Xie, Shitao

    In this paper, a fast mass transfer anaerobic inner loop fluidized bed biofilm reactor (ILFBBR) was developed to improve purified terephthalic acid (PTA) wastewater treatment. The emphasis of this study was on the start-up mode of the anaerobic ILFBBR, the hydraulic loadings and the operation stability. The biological morphology of the anaerobic biofilm in the reactors was also analyzed. The anaerobic column could operate successfully for 46 days due to the pre-aerating process. The anaerobic column had the capacity to resist shock loadings and maintained a high stable chemical oxygen demand (COD) and terephthalic acid removal rates at a hydraulic retention time of 5-10 h, even under conditions of organic volumetric loadings as high as 28.8 kg COD·m(-3).d(-1). The scanning electron microscope analysis of the anaerobic carrier demonstrated that clusters of prokaryotes grew inside of pores and that the filaments generated by pre-aeration contributed to the anaerobic biofilm formation and stability.

  6. Extracellular Polymers in Granular Sludge from Different Upflow Anaerobic Sludge Blanket (UASB) Reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1994-01-01

    Thermal extraction was used to quantify extracellular polymers (ECP) in granules from anaerobic upflow reactors. The optimal time for extraction was determined as the time needed before the intracellular material gives a significant contribution to the extracted extracellular material due to cell...... of an upflow anaerobic sludge blanket reactor from a sugar-containing waste-water to a synthetic waste-water containing acetate, propionate and butyrate resulted in a decrease in both the protein and polysaccharide content and an increase in the lipid content of the extracellular material. Furthermore...

  7. Kinetic evaluation and process performance of an upflow anaerobic filter reactor degrading terephthalic acid.

    Science.gov (United States)

    Davutluoglu, Orkun I; Seckin, Galip

    2014-01-01

    The anaerobic degradation of terephthalic acid (TA) as the sole organic carbon source was studied in an upflow anaerobic filter (UAF) reactor. The reactor was seeded with biomass obtained from a full-scale upflow anaerobic sludge bed (UASB) reactor and was used to treat wastewater from a petrochemical facility producing dimethyl terephthalate. The UAF reactor was operated for 252 d with a constant hydraulic retention time of 24 h, and the organic loading rate (OLR) was gradually increased from 1 to 10 g-chemical oxygen demand (COD)/L d. After a lag period of approximately 40 d, the COD removal efficiency increased exponentially and high removal rate values (≈90%) were obtained, except for at highest OLR (10 g-COD/L d). The high removal rates and the robustness of the reactor performance could be attributed to the formation of biofilm as well as granular sludge. The methane production rates (0.22 to 2.15 L/d) correlated well with the removed OLRs (0.3 to 6.8 g-COD/L d) during the various phases of treatment, indicating that the main mechanism of TA degradation occurs via methanogenic reactions. The average methane content of the produced biogas was 70.3%. The modified Stover-Kincannon model was found to be applicable for the anaerobic degradation of TA in UAFs (Umax = 64.5, KB = 69.1 g-COD/L d and Ymax = 0.27 L-CH4/g-CODremoved). These results suggest that UAF reactors are among the most effective reactor configurations for the anaerobic degradation of TA.

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

    Science.gov (United States)

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

    2011-10-15

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

  9. KINETIC MODELLING OF CONTINUOUS-MIX ANAEROBIC REACTORS OPERATING UNDER DIURNALLY CYCLIC TEMPERATURE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    E. A. Echiegu

    2014-01-01

    Full Text Available A two-culture dynamic model which incorporated the effects of diurnally cyclic temperature was developed and used to predict the dynamic response of anaerobic reactors operated on dairy manure under two diurnally cyclic temperature ranges of 20-40°C and 15-25°C which represent the summer and winter in Nigeria. The digesters were operated at various hydraulic retention times and solid concentrations and some useful kinetic parameters were determined. The model predicted biogas production, volatile solid reduction, methane yield and treatment efficiency with reasonable accuracy (R2 = 0.70 to 0.90. The model, however, under-predicted the cell mass concentration in the reactor probably because the Volatile Suspended Solid (VSS, which was used as the estimator of the actual cell mass concentration in the reactor, was not a good indicator of the active cell mass concentration in anaerobic reactors operating on dairy manure.

  10. Two-stage anaerobic fermentation of organic waste in CSTR and UFAF-reactors.

    Science.gov (United States)

    Held, Christof; Wellacher, Martin; Robra, Karl-Heinz; Gübitz, Georg M

    2002-01-01

    The mechanically separated liquid fraction of organic waste from households was used as a substrate for anaerobic fermentation. A two-step system consisting of a 2001 continuously stirred tank reactor (CSTR) and a 501 upflow anaerobic filter filled with glass foam pearls was constructed. The CSTR was operated for 5 months with a loading rate of 9.8 kg CSB m(-3) day(-1). At a resulting hydraulic retention time (HRT) of 24 days, 68% COD was degraded and a gas productivity of 4.0 m3 m(-3) day(-1) was achieved. Further digestion of the CSTR output was separately optimised in a 20 l-UFAF and based on these results a 50 l-UFAF was connected to the CSTR. At a resulting hydraulic retention time (HRT) of 6 days 38% COD was degraded and a gas productivity of 1.8 m3 m(-3) day(-1) was achieved with the 50 l-UFAF. Thus, the overall degradation efficiency of the two-phase system was 80%. The methane content (61%) of the biogas produced in the 50 l-UF

  11. Anaerobic filter reactor performance for the treatment of complex dairy wastewater at industrial scale.

    Science.gov (United States)

    Omil, Francisco; Garrido, Juan M; Arrojo, Belén; Méndez, Ramón

    2003-10-01

    The wastewaters discharged by raw milk quality control laboratories are more complex than the ones commonly generated by dairy factories because of the presence of certain chemicals such as sodium azide or chloramphenicol, which are used for preserving milk before analysis. The treatment of these effluents has been carried out in a full-scale plant comprising a 12 m(3) anaerobic filter (AF) reactor and a 28 m(3) sequential batch reactor (SBR). After more than 2 years of operation, a successful anaerobic treatment of these effluents was achieved, without fat removal prior to the anaerobic reactor. The organic loading rates maintained in the AF reactor were 5-6 kg COD/m(3) d, with COD removal being higher than 90%. No biomass washout was observed, and most of the fat contained in the wastewaters was successfully degraded. The addition of alkalinity is crucial for the maintenance of a proper buffer medium to ensure pH stability. The effluent of the AF reactor was successfully treated in the SBR reactor, and a final effluent with a COD content below 200 mg/l and total nitrogen below 10mg N/l was obtained.

  12. Performance of down-flow hanging sponge (DHS) reactor coupled with up-flow anaerobic sludge blanket (UASB) reactor for treatment of onion dehydration wastewater.

    Science.gov (United States)

    El-Kamah, Hala; Mahmoud, Mohamed; Tawfik, Ahmed

    2011-07-01

    In this study, a promising system consisting of up-flow anaerobic sludge blanket (UASB) reactor followed by down-flow hanging sponge (DHS) reactor was investigated for onion dehydration wastewater treatment. Laboratory experiments were conducted at two different phases, i.e., phase (1) at overall hydraulic retention time (HRT) of 11h (UASB reactor: 6h and DHS reactor: 5h) and phase (2) at overall HRT of 9.4h (UASB reactor: 5.2h and DHS reactor: 4.2h). Long-term operation results of the proposed system showed that its overall TCOD, TBOD, TSS, TKN and NH(4)-N removal efficiencies were 92 ± 5, 95 ± 2, 95 ± 2, 72 ± 6 and 99 ± 1.3%, respectively (phase 1). Corresponding values for the 2nd phase were 85.4 ± 5, 86 ± 3, 87 ± 6, 65 ± 8 and 95 ± 2.8%. Based on the available results, the proposed system could be more viable option for treatment of wastewater generated from onion dehydration industry in regions with tropical or sub-tropical climates and with stringent discharge standards.

  13. Bio-hydrogen production from molasses by anaerobic fermentation in continuous stirred tank reactor

    Science.gov (United States)

    Han, Wei; Li, Yong-feng; Chen, Hong; Deng, Jie-xuan; Yang, Chuan-ping

    2010-11-01

    A study of bio-hydrogen production was performed in a continuous flow anaerobic fermentation reactor (with an available volume of 5.4 L). The continuous stirred tank reactor (CSTR) for bio-hydrogen production was operated under the organic loading rates (OLR) of 8-32 kg COD/m3 reactor/d (COD: chemical oxygen demand) with molasses as the substrate. The maximum hydrogen production yield of 8.19 L/d was obtained in the reactor with the OLR increased from 8 kg COD/m3 reactor/d to 24 kg COD/m3 d. However, the hydrogen production and volatile fatty acids (VFAs) drastically decreased at an OLR of 32 kg COD/m3 reactor/d. Ethanoi, acetic, butyric and propionic were the main liquid fermentation products with the percentages of 31%, 24%, 20% and 18%, which formed the mixed-type fermentation.

  14. COMPARISON OF PHENOL REMOVAL IN ANAEROBIC FLUIDIZED BED REACTORS WITH SAND AND GAC MEDIA

    Directory of Open Access Journals (Sweden)

    A.R. Yazdanbakhsh; A.R. Mesdaghinia; A. Torabian; M. Shariat

    1997-08-01

    Full Text Available In this study two identical anaerobic completely mixed fluidized bed reactors with GAC and sand media were employed for COD & phenol removal. At loading rate of 1.6 g phenol L-1d-1, the efficiency of phenol removal in GAC & sand reactors were 97.7% & 74%, respectively. At high loading rate of phenol (6.09 g phenol I: 1d1 the efficiency of phenol removal in GAC reactor was better than 95%. In GAC reactor, the main mechanism for phenol removal at steady state condition was biological process; this was concluded through balance of gas production and COD removal. Better efficiency of GAC reactor comparing with sand reactor was because of resistance to fluctuations, higher surface for biomass growth and adsorption capacity of activated carbon.

  15. Simultaneous hydrogen utilization and in situ biogas upgrading in an anaerobic reactor

    DEFF Research Database (Denmark)

    Luo, Gang; Johansson, Sara; Boe, Kanokwan;

    2011-01-01

    . The methane production rate of the reactor with H2 addition was 22% higher, compared to the control reactor only fed with manure. The CO2 content in the produced biogas was only 15%, while it was 38% in the control reactor. However, the addition of hydrogen resulted in increase of pH (from 8.0 to 8.3) due......The possibility of converting hydrogen to methane and simultaneous upgrading of biogas was investigated in both batch tests and fully mixed biogas reactor, simultaneously fed with manure and hydrogen. Batch experiments showed that hydrogen could be converted to methane by hydrogenotrophic...... mixing intensity (shaking speed 300 rpm). Continuous addition of hydrogen (flow rate of 28.6 mL/(L/h)) to an anaerobic reactor fed with manure, showed that more than 80% of the hydrogen was utilized. The propionate and butyrate level in the reactor was not significantly affected by the hydrogen addition...

  16. Application of real-time PCR to determination of combined effect of antibiotics on Bacteria, Methanogenic Archaea, Archaea in anaerobic sequencing batch reactors.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2015-06-01

    This study evaluated the long-term effects of erythromycin-tetracycline-sulfamethoxazole (ETS) and sulfamethoxazole-tetracycline (ST) antibiotic combinations on the microbial community and examined the ways in which these antimicrobials impact the performance of anaerobic reactors. Quantitative real-time PCR was used to determine the effect that different antibiotic combinations had on the total and active Bacteria, Archae and Methanogenic Archae. Three primer sets that targeted metabolic genes encoding formylterahydrofolate synthetase, methyl-coenzyme M reductase and acetyl-coA synthetase were also used to determine the inhibition level on the mRNA expression of the homoacetogens, methanogens and specifically acetoclastic methanogens, respectively. These microorganisms play a vital role in the anaerobic degradation of organic waste and targeting these gene expressions offers operators or someone at a treatment plant the potential to control and the improve the anaerobic system. The results of the investigation revealed that acetogens have a competitive advantage over Archaea in the presence of ETS and ST combinations. Although the efficiency with which methane production takes place and the quantification of microbial populations in both the ETS and ST reactors decreased as antibiotic concentrations increased, the ETS batch reactor performed better than the ST batch reactor. According to the expression of genes results, the syntrophic interaction of acetogens and methanogens is critical to the performance of the ETS and ST reactors. Failure to maintain the stability of these microorganisms resulted in a decrease in the performance and stability of the anaerobic reactors.

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

    Science.gov (United States)

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

    2010-02-01

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

  18. Comparison of long-term performances and final microbial compositions of anaerobic reactors treating landfill leachate

    NARCIS (Netherlands)

    Calli, B.; Mertoglu, B.; Roest, C.; Inanc, B.

    2006-01-01

    Laboratory scale anaerobic upflow filter, sludge blanket and hybrid bed reactors were operated for 860 days in the treatment of high ammonia landfill leachate. Organic loading was gradually increased from 1.3 to 23.5 kg COD/m3 day in the start-up period and then fluctuated according to the COD conce

  19. Thermophilic anaerobic digestion of Lurgi coal gasification wastewater in a UASB reactor.

    Science.gov (United States)

    Wang, Wei; Ma, Wencheng; Han, Hongjun; Li, Huiqiang; Yuan, Min

    2011-02-01

    Lurgi coal gasification wastewater (LCGW) is a refractory wastewater, whose anaerobic treatment has been a severe problem due to its toxicity and poor biodegradability. Using a mesophilic (35±2°C) reactor as a control, thermophilic anaerobic digestion (55±2°C) of LCGW was investigated in a UASB reactor. After 120 days of operation, the removal of COD and total phenols by the thermophilic reactor could reach 50-55% and 50-60% respectively, at an organic loading rate of 2.5 kg COD/(m(3) d) and HRT of 24 h; the corresponding efficiencies were both only 20-30% in the mesophilic reactor. After thermophilic digestion, the wastewater concentrations of the aerobic effluent COD could reach below 200 mg/L compared with around 294 mg/L if mesophilic digestion was done and around 375 mg/L if sole aerobic pretreatment was done. The results suggested that thermophilic anaerobic digestion improved significantly both anaerobic and aerobic biodegradation of LCGW.

  20. Psychrophilic anaerobic digestion of swine manure slurry in sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Masse, D.I. [Agriculture Canada, Ottawa, ON (Canada). Food Research Branch; Droste, R.L. [Ottawa Univ., ON (Canada). Dept. of Civil Engineering

    1993-12-31

    This work presents preliminary results of an ongoing laboratory study to evaluate the feasibility of psychrophilic anaerobic digestion in sequencing batch reactors (SBR) for stabilizing, deodorizing and adding value to swine manure. Preliminary results show that the process is feasible. (author). 14 refs., 7 tabs.

  1. Selenate removal in methanogenic and sulfate-reducing upflow anaerobic sludge bed reactors

    NARCIS (Netherlands)

    Lenz, M.; Hullebusch, van E.D.; Hommes, G.; Corvini, P.F.X.; Lens, P.N.L.

    2008-01-01

    This paper evaluates the use of upflow anaerobic sludge bed (UASB) bioreactors (30 degrees C, pH = 7.0) to remove selenium oxyanions from contaminated waters (790 mu g Se L-1) under methanogenic and sulfate-reducing conditions using lactate as electron donor. One UASB reactor received sulfate at dif

  2. Chain elongation in anaerobic reactor microbiomes to recover resources from waste

    NARCIS (Netherlands)

    Spirito, C.M.; Richter, H.; Rabaey, K.; Stams, A.J.M.; Angenent, L.T.

    2014-01-01

    Different microbial pathways can elongate the carbon chains of molecules in open cultures of microbial populations (i.e. reactor microbiomes) under anaerobic conditions. Here, we discuss three such pathways: 1. homoacetogenesis to combine two carbon dioxide molecules into acetate; 2. succinate forma

  3. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    Ammonia is the most common inhibitor of anaerobic digestion (AD) process, resulting in suboptimal exploitation of the biogas potential of the feedstocks, causing significant economic losses to the biogas plants. Ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... of ammonia-rich organic waste in full-scale continuous reactors.......Ammonia is the most common inhibitor of anaerobic digestion (AD) process, resulting in suboptimal exploitation of the biogas potential of the feedstocks, causing significant economic losses to the biogas plants. Ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... methanogens are more robust to ammonia toxicity effect. It has been shown that bioaugmentation of a pure strain of a hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis) in an ammonia inhibited continuous anaerobic reactor can improve methane production more than 30%. Nevertheless, cultivation...

  4. Evaluation of a prereduced anaerobically sterilized medium (PRAS II) system for identification anaerobic microorganisms.

    Science.gov (United States)

    Beaucage, C M; Onderdonk, A B

    1982-09-01

    A prereduced, anaerobically sterilized system of tubed media (PRAS II; Scott Laboratories, Fiskeville, R.I.) was evaluated for accuracy in the identification of anerobic microorganisms. PRAS II was found to be a rapid and accurate identification system for obligate anaerobes which does not require the use of gas cannula inoculation or incubation in a special anaerobic environment.

  5. Evaluation of a prereduced anaerobically sterilized medium (PRAS II) system for identification anaerobic microorganisms.

    OpenAIRE

    Beaucage, C M; Onderdonk, A B

    1982-01-01

    A prereduced, anaerobically sterilized system of tubed media (PRAS II; Scott Laboratories, Fiskeville, R.I.) was evaluated for accuracy in the identification of anerobic microorganisms. PRAS II was found to be a rapid and accurate identification system for obligate anaerobes which does not require the use of gas cannula inoculation or incubation in a special anaerobic environment.

  6. Benefit of sodium hydroxide pretreatment of ensiled sorghum forage on the anaerobic reactor stability and methane production.

    Science.gov (United States)

    Sambusiti, C; Ficara, E; Malpei, F; Steyer, J P; Carrère, H

    2013-09-01

    The assessment of the pretreatment effect on the anaerobic digestion process is generally based on the results of batch tests, which may fail in truly predicting full-scale anaerobic reactors performance. Therefore, in this study, the effect of alkaline pretreatment on the anaerobic digestion of ensiled sorghum forage was evaluated by comparing the results of two semi-continuous CSTR (Continuously Stirred Tank Reactor) anaerobic reactors. Results showed that an alkaline pretreatment step, prior to the anaerobic digestion of ensiled sorghum forage, can have a beneficial effect both in enhancing methane production (an increase of 25% on methane production was observed, if compared to that of untreated sorghum) and in giving more stability to the anaerobic digestion process.

  7. Experimental and modeling study of a two-stage pilot scale high solid anaerobic digester system.

    Science.gov (United States)

    Yu, Liang; Zhao, Quanbao; Ma, Jingwei; Frear, Craig; Chen, Shulin

    2012-11-01

    This study established a comprehensive model to configure a new two-stage high solid anaerobic digester (HSAD) system designed for highly degradable organic fraction of municipal solid wastes (OFMSW). The HSAD reactor as the first stage was naturally separated into two zones due to biogas floatation and low specific gravity of solid waste. The solid waste was retained in the upper zone while only the liquid leachate resided in the lower zone of the HSAD reactor. Continuous stirred-tank reactor (CSTR) and advective-diffusive reactor (ADR) models were constructed in series to describe the whole system. Anaerobic digestion model No. 1 (ADM1) was used as reaction kinetics and incorporated into each reactor module. Compared with the experimental data, the simulation results indicated that the model was able to well predict the pH, volatile fatty acid (VFA) and biogas production.

  8. Application of acidogenic fixed-bed reactor prior to anaerobic membrane bioreactor for sustainable slaughterhouse wastewater treatment.

    Science.gov (United States)

    Saddoud, Ahlem; Sayadi, Sami

    2007-11-19

    High rate anaerobic treatment systems such as anaerobic membrane bioreactors (AMBR) are less popular for slaughterhouse wastewater due to the presence of high fat oil and suspended matters in the effluent. This affects the performance and efficiency of the treatment system. In this work, AMBR has been tried for slaughterhouse wastewater treatment. After the start up period, the reactor was operated with an average organic loading rate (OLR) of 4.37 kg TCODm(-3)d(-1) with gradual increase to an average of 13.27 kg TCODm(-3)d(-1). At stable conditions, the treatment efficiency was high with an average COD and BOD(5) reduction of 93.7 and 93.96%, respectively. However, a reduction in the AMBR performance was shown with the increase of the OLR to 16.32 kg TCODm(-3)d(-1). The removal efficiencies of SCOD and BOD(5) were drastically decreased to below 53.6 and 73.3%, respectively. The decrease of the AMBR performance was due to the accumulation of VFAs. Thus, a new integrated system composed of a FBR for the acidogenesis step followed by the AMBR for methanogenesis step was developed. At high ORL, the integrated system improved the performance of the anaerobic digestion and it successfully overcame the VFA accumulation problem in the AMBR. The anaerobic treatment led to a total removal of all tested pathogens. Thus, the microbiological quality of treated wastewater fits largely with WHO guidelines.

  9. The effects of operational and environmental variations on anaerobic wastewater treatment systems: a review

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R.C. [Embrapa Agroindustria Tropical (Brazilian Agricultural Research Corporation, Inst. of Tropical Agroindustry), Fortaleza (Brazil); Haandel, A.C. van [Federal University of Campina Grande (Brazil); Zeeman, G.; Lettinga, G. [Wageningen Univ. (Netherlands)

    2006-06-15

    With the aim of improving knowledge about the stability and reliability of anaerobic wastewater treatment systems, several researchers have studied the effects of operational or environmental variations on the performance of such reactors. In general, anaerobic reactors are affected by changes in external factors, but the severity of the effect is dependent upon the type, magnitude, duration and frequency of the imposed changes. The typical responses include a decrease in performance, accumulation of volatile fatty acids, drop in pH and alkalinity, change in biogas production and composition, and sludge washout. This review summarises the causes, types and effects of operational and environmental variation on anaerobic wastewater treatment systems. However, there still remain some unclear technical and scientific aspects that are necessary for the improvement of the stability and reliability of anaerobic processes. (author)

  10. Innovative self-powered submersible microbial electrolysis cell (SMEC) for biohydrogen production from anaerobic reactors.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2012-05-15

    A self-powered submersible microbial electrolysis cell (SMEC), in which a specially designed anode chamber and external electricity supply were not needed, was developed for in situ biohydrogen production from anaerobic reactors. In batch experiments, the hydrogen production rate reached 17.8 mL/L/d at the initial acetate concentration of 410 mg/L (5 mM), while the cathodic hydrogen recovery ( [Formula: see text] ) and overall systemic coulombic efficiency (CE(os)) were 93% and 28%, respectively, and the systemic hydrogen yield ( [Formula: see text] ) peaked at 1.27 mol-H(2)/mol-acetate. The hydrogen production increased along with acetate and buffer concentration. The highest hydrogen production rate of 32.2 mL/L/d and [Formula: see text] of 1.43 mol-H(2)/mol-acetate were achieved at 1640 mg/L (20 mM) acetate and 100 mM phosphate buffer. Further evaluation of the reactor under single electricity-generating or hydrogen-producing mode indicated that further improvement of voltage output and reduction of electron losses were essential for efficient hydrogen generation. In addition, alternate exchanging the electricity-assisting and hydrogen-producing function between the two cell units of the SMEC was found to be an effective approach to inhibit methanogens. Furthermore, 16S rRNA genes analysis showed that this special operation strategy resulted same microbial community structures in the anodic biofilms of the two cell units. The simple, compact and in situ applicable SMEC offers new opportunities for reactor design for a microbial electricity-assisted biohydrogen production system.

  11. Anaerobic biodegradation of spent sulphite liquor in a UASB reactor

    DEFF Research Database (Denmark)

    Jantsch, T.G.; Angelidaki, Irini; Schmidt, Jens Ejbye

    2002-01-01

    Anaerobic biodegradation of fermented spent sulphite liquor, SSL, which is produced during the manufacture of sulphite pulp, was investigated. SSL contains a high concentration of lignin products in addition to hemicellulose and has a very high COD load (173 g COD l1). Batch experiments with dilu......Anaerobic biodegradation of fermented spent sulphite liquor, SSL, which is produced during the manufacture of sulphite pulp, was investigated. SSL contains a high concentration of lignin products in addition to hemicellulose and has a very high COD load (173 g COD l1). Batch experiments...... such as incineration. Although the total COD reduction achieved is limited, bioenergy is produced and readily biodegradable matter is removed causing less load on post-treatment installations. 2002 Elsevier Science Ltd. All rights reserved....

  12. 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.

  13. Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor.

    Science.gov (United States)

    Majhi, Bijoy Kumar; Jash, Tushar

    2016-12-01

    Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m(3)kg(-1)VS, at OLR of 1.11-1.585kgm(-3)d(-1), were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation.

  14. Kinetic study of treatment of wastewater contains food preservative agent by anaerobic baffled reactor : An overview

    Science.gov (United States)

    Sumantri, Indro; Purwanto, Budiyono

    2015-12-01

    The characteristic of wastewater of food industries with preservative substances is high content of organic substances, degradable and high total suspended solid. High organic content in this waste forced the treatment is biologically and pointed out to anaerobic treatment. Anaerobic showed the better performance of degradation than aerobic for high content organic and also for toxic materials. During that day the treatment of food wastewater is aerobically which is high consume of energy required and high volume of sludge produced. The advantage of anaerobic is save high energy, less product of sludge, less requirement of nutrients of microorganism and high efficiency reduction of organic load. The high efficiency of reduction will reduce the load of further treatment, so that, the threshold limit based on the regulation would be easy to achieve. Research of treatment of wastewater of food industries would be utilized by both big scale industries and small industries using addition of preservative substances. The type reactor of anaerobic process is anaerobic baffled reactor that will give better contact between wastewater and microorganism in the sludge. The variables conducted in this research are the baffled configuration, sludge height, preservative agent contents, hydralic retention time and influence of micro nutrients. The respons of this research are the COD effluent, remaining preservative agent, pH, formation of volatile fatty acid and total suspended solid. The result of this research is kinetic model of the anaerobic baffled reactor, reaction kinetic of preservative agent degradation and technology of treatment wastewater contains preservative agent. The benefit of this research is to solve the treatment of wastewater of food industries with preservative substance in order to achieve wastewater limit regulation and also to prevent the environmental deterioration.

  15. Kinetic study of treatment of wastewater contains food preservative agent by anaerobic baffled reactor : An overview

    Energy Technology Data Exchange (ETDEWEB)

    Sumantri, Indro; Purwanto,; Budiyono [Chemical Engineering Department, Faculty of Engineering, Diponegoro University Jl. Prof. H. Soedarto, SH, Kampus Baru Tembalang, Semarang (Indonesia)

    2015-12-29

    The characteristic of wastewater of food industries with preservative substances is high content of organic substances, degradable and high total suspended solid. High organic content in this waste forced the treatment is biologically and pointed out to anaerobic treatment. Anaerobic showed the better performance of degradation than aerobic for high content organic and also for toxic materials. During that day the treatment of food wastewater is aerobically which is high consume of energy required and high volume of sludge produced. The advantage of anaerobic is save high energy, less product of sludge, less requirement of nutrients of microorganism and high efficiency reduction of organic load. The high efficiency of reduction will reduce the load of further treatment, so that, the threshold limit based on the regulation would be easy to achieve. Research of treatment of wastewater of food industries would be utilized by both big scale industries and small industries using addition of preservative substances. The type reactor of anaerobic process is anaerobic baffled reactor that will give better contact between wastewater and microorganism in the sludge. The variables conducted in this research are the baffled configuration, sludge height, preservative agent contents, hydralic retention time and influence of micro nutrients. The respons of this research are the COD effluent, remaining preservative agent, pH, formation of volatile fatty acid and total suspended solid. The result of this research is kinetic model of the anaerobic baffled reactor, reaction kinetic of preservative agent degradation and technology of treatment wastewater contains preservative agent. The benefit of this research is to solve the treatment of wastewater of food industries with preservative substance in order to achieve wastewater limit regulation and also to prevent the environmental deterioration.

  16. Anaerobic digestion of dairy wastewater by inverse fluidization: the inverse fluidized bed and the inverse turbulent bed reactors.

    Science.gov (United States)

    Arnaiz, C; Buffiere, P; Elmaleh, S; Lebrato, J; Moletta, R

    2003-11-01

    This paper describes the application of the inverse fluidization technology to the anaerobic digestion of dairy wastewater. Two reactors were investigated: the inverse fluidized bed reactor and the inverse turbulent reactor. In these reactors, a granular floating solid is expanded by a down-flow current of effluent or an up-flow current of gas, respectively. The carrier particles (Extendospheres) were chosen for their large specific surface area (20,000 m2m(-3)) and their low energy requirements for fluidization (gas velocity of 1.5 mm s(-1), 5.4 m h(-1)). Organic load was increased stepwise by reducing hydraulic retention time from more than 60 days to 3 days, while maintaining constant the feed COD concentration. Both reactors achieved more than 90% of COD removal, at an organic loading rate of 10-12 kgCOD m(-3) d(-1), respectively. The performances observed were similar or even higher than that of other previously tested fluidized bed technologies treating the same wastewater. It was found that the main advantages of this system are: low energy requirement, because of the low fluidization velocities required; there is no need of a settling device, because solids accumulate at the bottom of the reactor, so they can be easily drawn out and particles with high-biomass content can be easily recovered. Lipid phosphate concentration has been revealed as a good method for biomass estimation in biofilms since it only includes living biomass.

  17. Coproduction of hydrogen and methane via anaerobic fermentation of cornstalk waste in continuous stirred tank reactor integrated with up-flow anaerobic sludge bed.

    Science.gov (United States)

    Cheng, Xi-Yu; Li, Qian; Liu, Chun-Zhao

    2012-06-01

    A 10 L continuous stirred tank reactor (CSTR) system was developed for a two-stage hydrogen fermentation process with an integrated alkaline treatment. The maximum hydrogen production rate reached 218.5 mL/L h at a cornstalk concentration of 30 g/L, and the total hydrogen yield and volumetric hydrogen production rate reached 58.0 mL/g-cornstalk and 0.55-0.57 L/L d, respectively. A 10 L up-flow anaerobic sludge bed (UASB) was used for continuous methane fermentation of the effluents obtained from the two-stage hydrogen fermentation. At the optimal organic loading rate of 15.0 g-COD/Ld, the COD removal efficiency and volumetric biogas production rate reached 83.3% and 4.6L/Ld, respectively. Total methane yield reached 200.9 mL/g-cornstalk in anaerobic fermentation with the effluents and alkaline hydrolysate. As a result, the total energy recovery by coproduction of hydrogen and methane with anaerobic fermentation of cornstalk reached 67.1%.

  18. Thermochemical reactor systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Lipinski, Wojciech; Davidson, Jane Holloway; Chase, Thomas Richard

    2016-11-29

    Thermochemical reactor systems that may be used to produce a fuel, and methods of using the thermochemical reactor systems, utilizing a reactive cylindrical element, an optional energy transfer cylindrical element, an inlet gas management system, and an outlet gas management system.

  19. Tolerance of the antibiotic tylosin on treatment performance of an up-flow anaerobic stage reactor (UASR).

    Science.gov (United States)

    Chelliapan, S; Wilby, T; Sallis, P J; Yuzir, A

    2011-01-01

    Tylosin has been considered inhibiting COD removal in anaerobic digestion. In this study it is proven that this is not always the case. Accordingly, elevated concentrations of Tylosin (100-800mgL-1) could be tolerated by the anaerobic system. The influence of Tylosin concentrations on an up-flow anaerobic stage reactor (UASR) was assessed using additions of Tylosin phosphate concentrate. Results showed high efficiency for COD removal (average 93%) when Tylosin was present at concentrations ranging from 0 to 400 mg L-1. However, at Tylosin concentrations of 600 and 800 mg L-1 treatment efficiency declined to 85% and 75% removal respectively. The impact of Tylosin concentrations on archaeal activity were investigated and the analysis revealed that archaeal cells dominated the reactor, confirming that there was no detectable inhibition of the methanogens at Tylosin levels between 100 and 400mg L-1. Nevertheless, the investigation showed a slight reduction in the number of methanogens at Tylosin levels of 600 and 800 mg L-1. These results demonstrated that the methanogens were well adapted to Tylosin. It would not be expected that the process performance of the UASR would be affected, not even at a level well in excess of those appearing in real wastewater from a Tylosin production site.

  20. Coupled anaerobic-aerobic treatment of whey wastewater in a sequencing batch reactor: proof of concept.

    Science.gov (United States)

    Frigon, J C; Bruneau, T; Moletta, R; Guiot, S R

    2007-01-01

    A proof of concept was performed in order to verify if the coupling of anaerobic and aerobic conditions inside the same digester could efficiently treat a reconstituted whey wastewater at 21 degrees C. The sequencing batch reactor (SBR) cycles combined initial anaerobic phase and final aerobic phase with reduced aeration. A series of 24 h cycles in 0.5 L digesters, with four different levels of oxygenation (none, 54, 108 and 182 mgO2 per gram of chemical oxygen demand (COD)), showed residual soluble chemical oxygen demand (sCOD) of 683 +/- 46, 720 +/- 33, 581 +/- 45, 1239 +/- 15 mg L(-1), respectively. Acetate and hydrogen specific activities were maintained for the anaerobic digester, but decreased by 10-25% for the acetate and by 20-50% for the hydrogen, in the coupled digesters. The experiment was repeated using 48 h cycles with limited aeration during 6 or 16 hours at 54 and 108 mgO2gCODinitial(-1), displaying residual sCOD of 177 +/- 43, 137 +/- 38, 104 +/- 22 and 112 +/- 9 mgL(-1) for the anaerobic and the coupled digesters, respectively. The coupled digesters recovered after a pH shock with residual sCOD as low as 132 mg L(-1) compared to 636 mg L(-1) for the anaerobic digester. With regard to the obtained results, the feasibility of the anaerobic-aerobic coupling in SBR digesters for the treatment of whey wastewater was demonstrated.

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

    Science.gov (United States)

    Elmitwalli, Tarek

    2013-01-01

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

  2. Reactor vessel support system. [LMFBR

    Science.gov (United States)

    Golden, M.P.; Holley, J.C.

    1980-05-09

    A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

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

    Science.gov (United States)

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

    2015-03-01

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

  4. Trace metal dynamics in methanol fed anaerobic granular sludge bed reactors

    NARCIS (Netherlands)

    Zandvoort, M.H.

    2005-01-01

    Trace metals are essential for anaerobic microorganisms, because they are present as cofactor in many of their enzymes. Therefore anaerobic wastewater treatment systems using these microorganisms to perform biological conversions are dependent on these metals for their (optimal) performance. In prac

  5. Decolorizing and detoxifying textile wastewater, containing both soluble and insoluble dyes, in a full scale combined anaerobic/aerobic system.

    Science.gov (United States)

    Frijters, C T M J; Vos, R H; Scheffer, G; Mulder, R

    2006-03-01

    The wastewater originating from the bleaching and dyeing processes in the textile factory Ten Cate Protect in Nijverdal (the Netherlands) was successfully treated in a sequential anaerobic/aerobic system. In the system, a combination of an anaerobic 70-m3 fluidized bed reactor and a 450-m3 aerobic basin with integrated tilted plate settlers, 80-95% of the color was removed. The color was largely removed in the preacidification basin and the anaerobic reactor. Color, deriving from both reactive as well as disperse, was anaerobically removed, indicating that these type of dyes were reduced to colorless products. Interestingly, the vat dyes, the anthraquinones and indigoids, which were thought to be removed mainly aerobically, were largely anaerobically decolorized. Apparently the anaerobic system is capable of effectively removing the color of both soluble as insoluble dyes. The treated effluent of the sequential anaerobic/aerobic treatment showed no toxicity towards the bioluminescent bacterium Vibrio fisheri (EC20 (95%) > 45%). Partially bypassing the anaerobic stage resulted in increased toxicity (EC20 (95%) of 9% and 14%) in the effluent of the aerobic treatment and caused significant decrease of color removal. The results of this study show a main contribution of anaerobic treatment in decolorizing and detoxifying the textile wastewater in the sequential anaerobic/aerobic system.

  6. Molecular analysis of the biomass of a fluidized bed reactor treating synthetic vinasse at anaerobic and micro-aerobic conditions

    NARCIS (Netherlands)

    Rodriguez, E.; Lopes, A.; Fdz-Polanco, M.; Stams, A.J.M.; Garcia Encina, P.A.

    2012-01-01

    The microbial communities (Bacteria and Archaea) established in an anaerobic fluidized bed reactor used to treat synthetic vinasse (betaine, glucose, acetate, propionate, and butyrate) were characterized by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis. This study was focu

  7. CFD Simulation of an Anaerobic Membrane BioReactor (AnMBR to Treat Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Laura C. Zuluaga

    2015-06-01

    Full Text Available A Computational Fluid Dynamics (CFD simulation has been developed for an Anaerobic Membrane BioReactor (AnMBR to treat industrial wastewater. As the process consists of a side-stream MBR, two separate simulations were created: (i reactor and (ii membrane. Different cases were conducted for each one, so the surrounding temperature and the total suspended solids (TSS concentration were checked. For the reactor, the most important aspects to consider were the dead zones and the mixing, whereas for the ceramic membrane, it was the shear stress over the membrane surface. Results show that the reactor's mixing process was adequate and that the membrane presented higher shear stress in the 'triangular' channel.

  8. Anaerobic digestion of corn stovers for methane production in a novel bionic reactor.

    Science.gov (United States)

    Zhang, Meixia; Zhang, Guangming; Zhang, Panyue; Fan, Shiyang; Jin, Shuguang; Wu, Dan; Fang, Wei

    2014-08-01

    To improve the biogas production from corn stovers, a new bionic reactor was designed and constructed. The bionic reactor simulated the rumen digestion of ruminants. The liquid was separated from corn stovers and refluxed into corn stovers again, which simulated the undigested particles separated from completely digested materials and fed back again for further degradation in ruminant stomach. Results showed that the bionic reactor was effective for anaerobic digestion of corn stovers. The liquid amount and its reflux showed an obvious positive correlation with biogas production. The highest biogas production rate was 21.6 ml/gVS-addedd, and the total cumulative biogas production was 256.5 ml/gVS-added. The methane content in biogas ranged from 52.2% to 63.3%. The degradation of corn stovers were greatly enhanced through simulating the animal digestion mechanisms in this bionic reactor.

  9. STARTUP OF UPELOW ANAEROBIC SLUDGE BLANKET REACTOR FOR INDUSTRIAL WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    A.R. Mesdaghinia

    1994-06-01

    Full Text Available Up flow anaerobic sludge blanket (UASB reactors have been increasingly used for industrial wastewater treatment. Because of existing problems in startup step of these reactors, in this research the startup of a UASB in pilot scale and room temperature condition was studied. The total height of UASB reactor was 270 cm and effective height was 240 cm. Diameter of the reactor in lower part was 20 cm (reaction zone and 40 cm in upper part (solid-gas-liquid separator five sampling ports with interval of 32 cm were provided and the effective volume of the reactor was 100 liters. Septic tank digested sludge and cow manure were used for the seeding of UASB reactor. In the startup step of the reactor, volumetric loading was increased step by step. After 155 days granule formation was observed and after 215 days of the study the removal rate increased to 4.62 kg COD/m/ day. More than 98% of soluble COD removal was achieved in lower 160 cm of reactor.

  10. Biological treatment of phenolic wastewater in an anaerobic continuous stirred tank reactor

    Directory of Open Access Journals (Sweden)

    Firozjaee Taghizade Tahere

    2013-01-01

    Full Text Available In the present study, an anaerobic continuous stirred tank reactor (ACSTR with consortium of mixed culture was operated continuously for a period of 110 days. The experiments were performed with three different hydraulic retention times and by varying initial phenol concentrations between 100 to 1000 mg/L. A maximum phenol removal was observed at a hydraulic retention time (HRT of 4 days, with an organic loading rate (OLR of 170.86 mg/L.d. At this condition, phenol removal rate of 89% was achieved. In addition, the chemical oxygen demand (COD removal corresponds to phenol removal. Additional operating parameters such as pH, MLSS and biogas production rate of the effluents were also measured. The present study provides valuable information to design an anaerobic ACSTR reactor for the biodegradation of phenolic wastewater.

  11. Hydrodynamic characteristics of a four-compartment periodic anaerobic baffled reactor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Periodic anaerobic baffled reactor (PABR) is a novel reactor based on the design concept of anaerobic baffled reactor (ABR).Residence time distribution (RTD) studies on both clean and working reactors at the same hydraulic residence time (HRT) of 2 d were carried out to investigate the dead spaces and mixing patterns in PABRs at different organic loading rates (OLRs) in various switching manners and frequencies. The results showed that the fraction of dead space in PABR was similar to that in ABR, which was low in comparison with other reactor designs. Dead space may be divided into two categories, hydraulic and biological. In RTD studies without biomass, the hydraulic dead space in the PABR run in an "every second" switching manner with T = 2 d was the lowest whereas that in the PABR run in a T = ∞ (ABR) switching manner was the highest. The same trend was obtained with the total dead space in RTD studies with biomass no matter what the OLR was. Biological dead space was the major contributor to dead space but affected decreasingly at higher OLR whichever switching manner the PABR run in. The flow patterns within the PABRs were intermediate between plug-flow and perfectly mixed under all the conditions tested.

  12. Evaluation of Anaerobic Biofilm Reactor Kinetic Parameters Using Ant Colony Optimization.

    Science.gov (United States)

    Satya, Eswari Jujjavarapu; Venkateswarlu, Chimmiri

    2013-09-01

    Fixed bed reactors with naturally attached biofilms are increasingly used for anaerobic treatment of industry wastewaters due their effective treatment performance. The complex nature of biological reactions in biofilm processes often poses difficulty in analyzing them experimentally, and mathematical models could be very useful for their design and analysis. However, effective application of biofilm reactor models to practical problems suffers due to the lack of knowledge of accurate kinetic models and uncertainty in model parameters. In this work, an inverse modeling approach based on ant colony optimization is proposed and applied to estimate the kinetic and film thickness model parameters of wastewater treatment process in an anaerobic fixed bed biofilm reactor. Experimental data of pharmaceutical industry wastewater treatment process are used to determine the model parameters as a consequence of the solution of the rigorous mathematical models of the process. Results were evaluated for different modeling configurations derived from the combination of mathematical models, kinetic expressions, and optimization algorithms. Analysis of results showed that the two-dimensional mathematical model with Haldane kinetics better represents the pharmaceutical wastewater treatment in the biofilm reactor. The mathematical and kinetic modeling of this work forms a useful basis for the design and optimization of industry wastewater treating biofilm reactors.

  13. Rational Basis for Designing Horizontal-Flow Anaerobic Immobilized Sludge (HAIS Reactor for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    M. Zaiat

    1997-03-01

    Full Text Available The conception and development on a rational basis of a new configuration of anaerobic fixed-bed bioreactor for wastewater treatment, the horizontal-flow anaerobic immobilized sludge (HAIS reactor, is presented. Such a reactor containing immobilized sludge in polyurethane foam matrices was first assayed for treating paper industry wastewater. A very short start-up period was observed and the reactor achieved stable operation by the eighth day. Afterwards, fundamental aspects of the process were investigated in order to obtain a rational basis for HAIS reactor design. A sequence of experiments was carried out for evaluating the cell wash-out from polyurethane foam matrices, the liquid-phase mass transfer coefficient and the intrinsic kinetic parameters, besides the hydrodynamic flow pattern of the reactor. The knowledge of such fundamental phenomena is useful for improving the reactor’s design and operation. Besides, these fundamental studies are essential to provide parameters for simulation and optimization of processes that make use of immobilized biomass

  14. Effect of substrate concentration on dark fermentation hydrogen production using an anaerobic fluidized bed reactor.

    Science.gov (United States)

    de Amorim, Eduardo Lucena Cavalcante; Sader, Leandro Takano; Silva, Edson Luiz

    2012-03-01

    The effect of substrate (glucose) concentration on the stability and yield of a continuous fermentative process that produces hydrogen was studied. Four anaerobic fluidized bed reactors (AFBRs) were operated with a hydraulic retention time (HRT) from 1 to 8 h and an influent glucose concentration from 2 to 25 g L(-1). The reactors were inoculated with thermally pre-treated anaerobic sludge and operated at a temperature of 30 °C with an influent pH around 5.5 and an effluent pH of about 3.5. The AFBRs with a HRT of 2 h and a feed strength of 2, 4, and 10 g L(-1) showed satisfactory H(2) production performance, but the reactor fed with 25 g L(-1) of glucose did not. The highest hydrogen yield value was obtained in the reactor with a glucose concentration of 2 g L(-1) when it was operated at a HRT of 2 h. The maximum hydrogen production rate value was achieved in the reactor with a HRT of 1 h and a feed strength of 10 g L(-1). The AFBRs operated with glucose concentrations of 2 and 4 g L(-1) produced greater amounts of acetic and butyric acids, while AFBRs with higher glucose concentrations produced a greater amount of solvents.

  15. Hollow fiber membrane based H-2 diffusion for efficient in situ biogas upgrading in an anaerobic reactor

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2013-01-01

    Bubbleless gas transfer through a hollow fiber membrane (HFM) module was used to supply H2 to an anaerobic reactor for in situ biogas upgrading, and it creates a novel system that could achieve a CH4 content higher than 90 % in the biogas. The increase of CH4 content and pH, and the decrease of b...... also demonstrated that the biofilm formed on the membrane only contributed 22-36 % to the H2 consumption, while most of the H2 was consumed by the microorganisms in the liquid phase....

  16. The degradability of biodegradable plastics in aerobic and anaerobic waste landfill model reactors.

    Science.gov (United States)

    Ishigaki, Tomonori; Sugano, Wataru; Nakanishi, Akane; Tateda, Masafumi; Ike, Michihiko; Fujita, Masanori

    2004-01-01

    Degradabilities of four kinds of commercial biodegradable plastics (BPs), polyhydroxybutyrate and hydroxyvalerate (PHBV) plastic, polycaprolactone plastic (PCL), blend of starch and polyvinyl alcohol (SPVA) plastic and cellulose acetate (CA) plastic were investigated in waste landfill model reactors that were operated as anaerobically and aerobically. The application of forced aeration to the landfill reactor for supplying aerobic condition could potentially stimulate polymer-degrading microorganisms. However, the individual degradation behavior of BPs under the aerobic condition was completely different. PCL, a chemically synthesized BP, showed film breakage under the both conditions, which may have contributed to a reduction in the waste volume regardless of aerobic or anaerobic conditions. Effective degradation of PHBV plastic was observed in the aerobic condition, though insufficient degradation was observed in the anaerobic condition. But the aeration did not contribute much to accelerate the volume reduction of SPVA plastic and CA plastic. It could be said that the recalcitrant portions of the plastics such as polyvinyl alcohol in SPVA plastic and the highly substituted CA in CA plastic prevented the BP from degradation. These results indicated existence of the great variations in the degradability of BPs in aerobic and anaerobic waste landfills, and suggest that suitable technologies for managing the waste landfill must be combined with utilization of BPs in order to enhance the reduction of waste volume in landfill sites.

  17. Cassava Stillage Treatment by Thermophilic Anaerobic Continuously Stirred Tank Reactor (CSTR)

    Science.gov (United States)

    Luo, Gang; Xie, Li; Zou, Zhonghai; Zhou, Qi

    2010-11-01

    This paper assesses the performance of a thermophilic anaerobic Continuously Stirred Tank Reactor (CSTR) in the treatment of cassava stillage under various organic loading rates (OLRs) without suspended solids (SS) separation. The reactor was seeded with mesophilic anaerobic granular sludge, and the OLR increased by increments to 13.80 kg COD/m3/d (HRT 5d) over 80 days. Total COD removal efficiency remained stable at 90%, with biogas production at 18 L/d (60% methane). Increase in the OLR to 19.30 kg COD/m3/d (HRT 3d), however, led to a decrease in TCOD removal efficiency to 79% due to accumulation of suspended solids and incomplete degradation after shortened retention time. Reactor performance subsequently increased after OLR reduction. Alkalinity, VFA and pH levels were not significantly affected by OLR variation, indicating that no additional alkaline or pH adjustment is required. More than half of the SS in the cassava stillage could be digested in the process when HRT was 5 days, which demonstrated the suitability of anaerobic treatment of cassava stillage without SS separation.

  18. Biologic treatment of wastewater from cassava flour production using vertical anaerobic baffled reactor (VABR

    Directory of Open Access Journals (Sweden)

    Gleyce T Correia

    2008-08-01

    Full Text Available The estimate cassava production in Brazil in 2007 was of 25 million tons (= 15% of the world production and most of it is used in the production of flour. During its processing, waste that can cause environmental inequality is generated, if discharged inappropriately. One of the liquid waste generated, manipueira, is characterized by its high level of organic matter. The anaerobic treatment that uses a vertical anaerobic baffled reactor (VABR inoculated with granulated sludge, is one of the ways of treating this effluent. The anaerobic biodigestion phases are separated in this kind of reactor, allowing greater stability and resistance to load shocks. The VABR was built with a width/height rate of 1:2. The pH, acidity, alkalinity, turbidity and COD removal were analyzed in 6 different regions of the reactor, which was operated with an increasing feeding from ? 2000 to ? 10000 mg COD L?¹ and HRT between 6.0 and 2.5 days. The VABR showed decreasing acidity and turbidity, an increase in alkalinity and pH, and 96% efficiency in COD removal with 3-day HRT and feeding of 3800 mg COD L?¹.

  19. Potential for anaerobic conversion of xenobiotics

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Dolfing, J.; Haagensen, Frank;

    2003-01-01

    This review covers the latest research on the anaerobic biodegradation of aromatic xenobiotic compounds, with emphasis on surfactants, polycyclic aromatic hydrocarbons, phthalate esters, polychlorinated biphenyls, halogenated phenols, and pesticides. The versatility of anaerobic reactor systems...

  20. Removal of steroid estrogens from municipal wastewater in a pilot scale expanded granular sludge blanket reactor and anaerobic membrane bioreactor

    Science.gov (United States)

    Ito, Ayumi; Mensah, Lawson; Cartmell, Elise; Lester, John N.

    2016-01-01

    Anaerobic treatment of municipal wastewater offers the prospect of a new paradigm by reducing aeration costs and minimizing sludge production. It has been successfully applied in warm climates, but does not always achieve the desired outcomes in temperate climates at the biochemical oxygen demand (BOD) values of municipal crude wastewater. Recently the concept of ‘fortification' has been proposed to increase organic strength and has been demonstrated at the laboratory and pilot scale treating municipal wastewater at temperatures of 10–17°C. The process treats a proportion of the flow anaerobically by combining it with primary sludge from the residual flow and then polishing it to a high effluent standard aerobically. Energy consumption is reduced as is sludge production. However, no new treatment process is viable if it only addresses the problems of traditional pollutants (suspended solids – SS, BOD, nitrogen – N and phosphorus – P); it must also treat hazardous substances. This study compared three potential municipal anaerobic treatment regimes, crude wastewater in an expanded granular sludge blanket (EGSB) reactor, fortified crude wastewater in an EGSB and crude wastewater in an anaerobic membrane bioreactor. The benefits of fortification were demonstrated for the removal of SS, BOD, N and P. These three systems were further challenged with the removal of steroid estrogens at environmental concentrations from natural indigenous sources. All three systems removed these compounds to a significant degree, confirming that estrogen removal is not restricted to highly aerobic autotrophs, or aerobic heterotrophs, but is also a faculty of anaerobic bacteria. PMID:26212345

  1. Microbial populations of an upflow anaerobic sludge blanket reactor treating wastewater from a gelatin industry.

    Science.gov (United States)

    Vieira, A M; Bergamasco, R; Gimenes, M L; Nakamura, C V; Dias Filho, B P

    2001-12-01

    The microbial populations of an upflow anaerobic sludge blanket reactor, used for treating wastewater from the gelatin industry, were studied by microbiological methods and phase-contrast and electron microscopy. Microscopy examination of the sludge showed a complex mixture of various rod-shaped and coccoid bacterial pluslong filaments and verymobile curved rods. In addition free-living anaerobic ciliates and flagellates were also observed. The trophic group population observed in decreasing order of dominance were hydrolytic and acetogenic at 10(6) and sulfate reducing and methanogenic at 10(5). The rate of methane production in anaerobic granular sludge cultivated in growth medium supplement with formate pressurized with H2:CO2 showed a significant increase in methane yield compared with theseed culture containingthe same substrate and atmosphere of N2:CO2. Similar rates of methane production were observed when the growth medium was supplemented with acetate pressurized either with H2:CO2 or N2:CO2. The number of total anaerobic bacteria at 10(7), fecal coliforms and total coliforms at 10(6), and fecal streptococci at 10(3) is based on colony counts on solid media. The four prevalent species of facultative anaerobic gram-negative bacteria that belong to the family of Enterobacteriaceae were identified as Escherichia coli, Esherichia fergusonii, Klebsiella oxytoca, and Citrobacter freundii. The species Aeromonas hydrophila, Aeromonas veronii, Acinetobacter iwoffi and Stenotrophomonas maltophila were the most frequently isolated glucose fermenting and nonfermenting gram-negative bacilli.

  2. Performance and microbial community analysis of the anaerobic reactor with coke oven gas biomethanation and in situ biogas upgrading

    DEFF Research Database (Denmark)

    Wang, Wen; Xie, Li; Luo, Gang;

    2013-01-01

    (HFM). With pH control at 8.0, the added H2 and CO were fully consumed and no negative effects on the anaerobic degradation of sewage sludge were observed. The maximum CH4 content in the biogas was 99%. The addition of SCOG resulted in enrichment and dominance of homoacetogenetic genus Treponema......A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane...

  3. Mesophilic and thermophilic anaerobic co-digestion of abattoir wastewater and fruit and vegetable waste in anaerobic sequencing batch reactors.

    Science.gov (United States)

    Bouallagui, Hassib; Rachdi, Boutheina; Gannoun, Hana; Hamdi, Moktar

    2009-06-01

    Anaerobic co-digestion of fruit and vegetable waste (FVW) and abattoir wastewater (AW) was investigated using anaerobic sequencing batch reactors (ASBRs). The effects of hydraulic retention time (HRT) and temperature variations on digesters performances were examined. At both 20 and 10 days biogas production for co-digestion was greater thanks to the improved balance of nutrients. The high specific gas productions for the different digestion processes were 0.56, 0.61 and 0.85 l g(-1) total volatile solids (TVS) removal for digesters treating AW, FVW and AW + FVW, respectively. At an HRT of 20 days, biogas production rates from thermophilic digesters were higher on average than from mesophilic AW, FVW and AW + FVW digestion by 28.5, 44.5 and 25%, respectively. However, at 10 days of HRT results showed a decrease of biogas production rate for AW and AW + FVW digestion processes due to the high amount of free ammonia at high organic loading rate (OLR).

  4. Continuous removal and recovery of tellurium in an upflow anaerobic granular sludge bed reactor.

    Science.gov (United States)

    Mal, Joyabrata; Nancharaiah, Yarlagadda V; Maheshwari, Neeraj; van Hullebusch, Eric D; Lens, Piet N L

    2017-04-05

    Continuous removal of tellurite (TeO3(2-)) from synthetic wastewater and subsequent recovery in the form of elemental tellurium was studied in an upflow anaerobic granular sludge bed (UASB) reactor operated at 30°C. The UASB reactor was inoculated with anaerobic granular sludge and fed with lactate as carbon source and electron donor at an organic loading rate of 0.6g CODL(-1)d(-1). After establishing efficient and stable COD removal, the reactor was fed with 10mg TeO3(2-)L(-1) for 42 d before increasing the influent concentration to 20mg TeO3(2-)L(-1). Tellurite removal (98 and 92%, respectively, from 10 and 20mg TeL(-1)) was primarily mediated through bioreduction and most of the removed Te was retained in the bioreactor. Characterization using XRD, Raman spectroscopy, SEM-EDX and TEM confirmed association of tellurium with the granular sludge, typically in the form of elemental Te(0) deposits. Furthermore, application of an extracellular polymeric substances (EPS) extraction method to the tellurite reducing sludge recovered up to 78% of the tellurium retained in the granular sludge. This study demonstrates for the first time the application of a UASB reactor for continuous tellurite removal from tellurite-containing wastewater coupled to elemental Te(0) recovery.

  5. Concerning the role of cell lysis-cryptic growth in anaerobic side-stream reactors: the single-cell analysis of viable, dead and lysed bacteria.

    Science.gov (United States)

    Foladori, P; Velho, V F; Costa, R H R; Bruni, L; Quaranta, A; Andreottola, G

    2015-05-01

    In the Anaerobic Side-Stream Reactor (ASSR), part of the return sludge undergoes alternating aerobic and anaerobic conditions with the aim of reducing sludge production. In this paper, viability, enzymatic activity, death and lysis of bacterial cells exposed to aerobic and anaerobic conditions for 16 d were investigated at single-cell level by flow cytometry, with the objective of contributing to the understanding of the mechanisms of sludge reduction in the ASSR systems. Results indicated that total and viable bacteria did not decrease during the anaerobic phase, indicating that anaerobiosis at ambient temperature does not produce a significant cell lysis. Bacteria decay and lysis occurred principally under aerobic conditions. The aerobic decay rate of total bacteria (bTB) was considered as the rate of generation of lysed bacteria. Values of bTB of 0.07-0.11 d(-1) were measured in anaerobic + aerobic sequence. The enzymatic activity was not particularly affected by the transition from anaerobiosis to aerobiosis. Large solubilisation of COD and NH4(+) was observed only under anaerobic conditions, as a consequence of hydrolysis of organic matter, but not due to cell lysis. The observations supported the proposal of two independent mechanisms contributing equally to sludge reduction: (1) under anaerobic conditions: sludge hydrolysis of non-bacterial material, (2) under aerobic conditions: bacterial cell lysis and oxidation of released biodegradable compounds.

  6. Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Ahring, Birgitte Kiær

    2002-01-01

    Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 mumol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon...

  7. Comparison of the microbial communities in solid-state anaerobic digestion (SS-AD) reactors operated at mesophilic and thermophilic temperatures.

    Science.gov (United States)

    Li, Yueh-Fen; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Li, Yebo; Yu, Zhongtang

    2015-01-01

    The microbiomes involved in liquid anaerobic digestion process have been investigated extensively, but the microbiomes underpinning solid-state anaerobic digestion (SS-AD) are poorly understood. In this study, microbiome composition and temporal succession in batch SS-AD reactors, operated at mesophilic or thermophilic temperatures, were investigated using Illumina sequencing of 16S rRNA gene amplicons. A greater microbial richness and evenness were found in the mesophilic than in the thermophilic SS-AD reactors. Firmicutes accounted for 60 and 82 % of the total Bacteria in the mesophilic and in the thermophilic SS-AD reactors, respectively. The genus Methanothermobacter dominated the Archaea in the thermophilic SS-AD reactors, while Methanoculleus predominated in the mesophilic SS-AD reactors. Interestingly, the data suggest syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis as an important pathway for biogas production during the thermophilic SS-AD. Canonical correspondence analysis (CCA) showed that temperature was the most influential factor in shaping the microbiomes in the SS-AD reactors. Thermotogae showed strong positive correlation with operation temperature, while Fibrobacteres, Lentisphaerae, Spirochaetes, and Tenericutes were positively correlated with daily biogas yield. This study provided new insight into the microbiome that drives SS-AD process, and the findings may help advance understanding of the microbiome in SS-AD reactors and the design and operation of SS-AD systems.

  8. Phenol degradation in an anaerobic fluidized bed reactor packed with low density support materials

    Directory of Open Access Journals (Sweden)

    G. P. Sancinetti

    2012-03-01

    Full Text Available The objective of this research was to study phenol degradation in anaerobic fluidized bed reactors (AFBR packed with polymeric particulate supports (polystyrene - PS, polyethylene terephthalate - PET, and polyvinyl chloride - PVC. The reactors were operated with a hydraulic retention time (HRT of 24 h. The influent phenol concentration in the AFBR varied from 100 to 400 mg L-1, resulting in phenol removal efficiencies of ~100%. The formation of extracellular polymeric substances yielded better results with the PVC particles; however, deformations in these particles proved detrimental to reactor operation. PS was found to be the best support for biomass attachment in an AFBR for phenol removal. The AFBR loaded with PS was operated to analyze the performance and stability for phenol removal at feed concentrations ranging from 50 to 500 mg L-1. The phenol removal efficiency ranged from 90-100%.

  9. Simultaneous Coproduction of Hydrogen and Ethanol in Anaerobic Packed-Bed Reactors

    OpenAIRE

    Cristiane Marques dos Reis; Edson Luiz Silva

    2014-01-01

    This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT) (1–8 h). Two reactors filled with expanded clay and fed with glucose (3136–3875 mg L−1) were operated at different total upflow velocities: 0.30 cm s−1 (R030) and 0.60 cm s−1 (R060). The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3 and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h−1 L−1 in R030 at...

  10. Thermal hygienization of excess anaerobic sludge: a possible self-sustained application of biogas produced in UASB reactors.

    Science.gov (United States)

    Borges, E S M; Godinho, V M; Chernicharo, C A L

    2005-01-01

    The main current trends in final disposal of sludge from Wastewater Treatment Plants (WTP) include: safe use of nutrients and organic matter in agriculture, sludge disinfection and restricted use in landfill. As to sludge hygienization, helminth eggs have been used as a major parameter to determine the effectiveness of such process, and its inactivation can be reached by means of thermal treatment, under varying temperature and other conditions. In such context, the objective of this research was to determine how effectively biogas produced in UASB reactors could be used as a source of calorific energy for the thermal hygienization of excess anaerobic sludge, with Ascaris lumbricoides eggs being used as indicator microorganisms, and whether the system can operate on a self-sustained basis. The experiments were conducted in a pilot-scale plant comprising one UASB reactor, two biogas holders and one thermal reactor. The investigation proved to be of extreme importance to developing countries, since it leads to a simplified and fully self-sustainable solution for sludge hygienization, while making it possible to reuse such material for agricultural purposes. It should be also noted that using biogas from UASB reactors is more than sufficient to accomplish the thermal hygienization of all excess sludge produced by this system, when used for treating domestic sewage.

  11. High-Rate Anaerobic Side-Stream Reactor (ASSR) Processes to Minimize the Production of Excess Sludge.

    Science.gov (United States)

    Park, Chul; Chon, Dong-Hyun

    2015-12-01

    High-rate anaerobic side-stream reactor (ASSR) processes were developed to minimize excess sludge production during wastewater treatment. New ASSRs were operated in 2.5-day solids retention time (SRT), much shorter than 10-day SRT used by the commercial sludge reduction process. The 2.5-day was selected based on literature review and preliminary studies, showing that maximum solublization of key floc components, such as divalent cations, extracellular polymeric substances (EPS), and protease, occur within 2 to 3 days of anaerobic digestion. The laboratory reactor study showed that 2.5-day ASSR systems produced approximately 60 and 20% less sludge than the control (no ASSR) and the 10-day ASSR, respectively. The experimental systems showed acceptable effluent quality, despite minimal sludge wastage. This was possible because sludge EPS were continuously released/degraded and regenerated as sludge underwent recirculation between ASSR and the aerobic basin. The results supported that the activated sludge process incorporating small ASSRs significantly decrease the production of excess sludge during wastewater treatment.

  12. Startup of anaerobic fluidized bed reactors with acetic acid as the substrate.

    Science.gov (United States)

    Hsu, Y; Shieh, W K

    1993-02-05

    The startup of anaerobic fluidized bed reactors, which use Manville R-633 beads as the growth support media, acetate enriched bacterial culture as the inoculum, and acetic acid as the sole substrate, is studied. Tow startup strategies are evaluated: one based on maximum and stable substrate utilization and another based on maximum substrate loading controlled by reactor pH. The startup process is characterized using a number of operational parameters.The reactors again excellent total organic carbon (TOC) removal (i.e., > 97% at a feed concentration of 5000 mg TOC/L) and stable methane production (i.e., 0.90 L CH(4)/g TOC, where TOC(r) is TOC removed) at a early stage of the startup process, regardless of the strategies applied. The loading can be increased rapidly without the danger of being overloaded. Significant losses of growth support media and biomass caused by gas effervescence at higher loadings limits the maximum loading that can be safely applied during startup process.A high reactor immobilized biomass inventory is achievable using the porous growth support media (e.g., Manville 633 beads). A rapid increase in loading creates a substrate rich environment that yields more viable reactor biomass. Both substrate utilization rate (batch and continuous) and immobilized biomass inventory stabilize concomitantly at the late stage of the startup process, indicating the attainment of steady-state conditions in reactors. Therefore, they are better parameters that TOC removal and methane production for characterizing the entire startup process of aerobic fluidized bed reactor.The strategy based on maximum substrate loading controlled by reactor pH significantly shortens the startup time. In this case, the reactor attains steady-state conditions approximately 140 days after startup. On the other hand, a startup time of 200 days is required when the strategy based maximum substrate utilization is adopted.

  13. Simultaneous hydrogen utilization and in situ biogas upgrading in an anaerobic reactor.

    Science.gov (United States)

    Luo, Gang; Johansson, Sara; Boe, Kanokwan; Xie, Li; Zhou, Qi; Angelidaki, Irini

    2012-04-01

    The possibility of converting hydrogen to methane and simultaneous upgrading of biogas was investigated in both batch tests and fully mixed biogas reactor, simultaneously fed with manure and hydrogen. Batch experiments showed that hydrogen could be converted to methane by hydrogenotrophic methanogenesis with conversion of more than 90% of the consumed hydrogen to methane. The hydrogen consumption rates were affected by both P(H₂) (hydrogen partial pressure) and mixing intensity. Inhibition of propionate and butyrate degradation by hydrogen (1 atm) was only observed under high mixing intensity (shaking speed 300 rpm). Continuous addition of hydrogen (flow rate of 28.6 mL/(L/h)) to an anaerobic reactor fed with manure, showed that more than 80% of the hydrogen was utilized. The propionate and butyrate level in the reactor was not significantly affected by the hydrogen addition. The methane production rate of the reactor with H₂ addition was 22% higher, compared to the control reactor only fed with manure. The CO₂ content in the produced biogas was only 15%, while it was 38% in the control reactor. However, the addition of hydrogen resulted in increase of pH (from 8.0 to 8.3) due to the consumption of bicarbonate, which subsequently caused slight inhibition of methanogenesis.

  14. Effects of hydraulic retention time and nitrobenzene concentration on the performance of sequential upflow anaerobic filter and air lift reactors in treating nitrobenzene-containing wastewater

    DEFF Research Database (Denmark)

    Wu, Jinhua; Chen, Guocai; Gu, Jingjing;

    2014-01-01

    Sequential upflow anaerobic filter (UAF)/air lift (ALR) reactors were employed to investigate the effects of hydraulic retention time (HRT) and nitrobenzene (NB) concentration on treatment of NB-containing wastewater. The results showed that NB was effectively reduced to aniline (AN) with glucose...... and the influent NB concentration increased from 400 to 800 mg l super(-1), respectively. The results showed that sequential UAF/ALR system can be operated at low HRTs and high NB concentrations without significantly affecting the removal efficiency of NB in the reactor system. The UAF/ALR system can provide...... an effective yet low cost method for treatment of NB-containing industrial wastewater....

  15. Buoyant Filter Bio-Reactor (BFBR)--a novel anaerobic wastewater treatment unit.

    Science.gov (United States)

    Panicker, Soosan J; Philipose, M C; Haridas, Ajit

    2008-01-01

    The Buoyant Filter Bio-Reactor (BFBR) is a novel and very efficient method for the treatment of complex wastewater. Sewage is a complex wastewater containing insoluble COD contributed by fat and proteins. The fat and proteins present in the domestic sewage cause operational problems and underperformance in the Upflow Anaerobic Sludge Blanket Reactor, used now for treating sewage anaerobically. The biogas yield from the BFBR is 0.36 m3/kg COD reduced and the methane content was about 70-80%. Production of methane by anaerobic digestion of organic waste had the benefit of lower energy costs for treatment and is thus environmentally beneficial to the society by providing a clean fuel from renewable feed stocks. The BFBR achieved a COD removal efficiency of 80-90% for an organic loading rate of 4.5 kg/m3/d at a hydraulic retention time of 3.25 hours. The effluent COD was less than 100 mg/l, thus saving on secondary treatment cost. No pretreatment like sedimentation was required for the influent to the BFBR. The BFBR can produce low turbidity effluent as in the activated sludge process (ASP). The land area required for the BFBR treatment plant is less when compared to ASP plant. Hence the problem of scarcity of land for the treatment plant is reduced. The total expenditure for erecting the unit was less than 50% as that of conventional ASP for the same COD removal efficiency including land cost.

  16. Modeling simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater.

    Science.gov (United States)

    Mendes, Carlos; Esquerre, Karla; Queiroz, Luciano Matos

    2016-07-15

    This paper presents a mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate the effects of nitrate concentration and hydraulic retention time (HRT) on the simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater. The model was calibrated using previously published experimental data obtained from anaerobic batch tests for different COD/ [Formula: see text] ratios. Model simulations were performed to predict the SCNR in a completely mixed reactor (CSTR) operating under mesophilic conditions (35 °C). Six different scenarios were evaluated to investigate the performance of the SCNR based on typical influent characteristics of domestic wastewater. The variables analyzed were chemical oxygen demand (COD) removal, nitrate concentration, methane production, nitrogen gas, volatile fatty acids (VFA) concentration, pH and percentage of COD used by the denitrifying and methanogenic microorganisms. The HRT was decreased stepwise from 15 to 4 h. The results indicate that Scenario (S5) with a COD/ [Formula: see text] ratio equal to 10 and an HRT equal to 15 h ensures the occurrence of the stable SCNR. Furthermore, the accumulation of denitrification intermediates and a significant reduction in the biogas production when the organic matter is limited was verified.

  17. Biodegradation of linear alkylbenzene sulfonate in commercial laundry wastewater by an anaerobic fluidized bed reactor.

    Science.gov (United States)

    Braga, Juliana K; Motteran, Fabrício; Macedo, Thaís Z; Sakamoto, Isabel K; Delforno, Tiago P; Okada, Dagoberto Y; Silva, Edson L; Varesche, Maria Bernadete A

    2015-01-01

    The biodegradation of linear alkylbenzene sulfonate (LAS) from commercial laundry wastewater was evaluated in an anaerobic fluidized bed reactor (FBR) fed with synthetic substrate (598 mg L(-1) to 723 mg L(-1) of organic matter) supplemented with 9.5±3.1 mg L(-1) to 27.9±9.6 mg L(-1) of LAS. The average chemical oxygen demand (COD) removal efficiency was 89% and the biodegradation of LAS was 57% during the 489 days of anaerobic FBR. Higher levels of volatile fatty acids (VFA) were observed in the effluent at the stage with the best LAS removal performance. Increasing the surfactant concentration did not increase the VFA production in the effluent. The predominant VFAs after the addition of LAS were as follows: isovaleric acid and valeric acid, followed by propionic acid, caproic acid and formic acid. The similarities of 64% and 45% to Archaea and Bacteria domains were observed in the samples taken in the operating period of anaerobic FBR fed with 23.6±10 mg L(-1) and 27.9±10 mg L(-1) of LAS. During the operation stages in the reactor, Gemmatimonas, Desulfobulbus and Zoogloea were determined as the most abundant genera related to surfactant degradation using 454-Pyrosequencing.

  18. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source

    OpenAIRE

    Gürtekin, Engin; ŞEKERDAĞ, Nusret

    2015-01-01

    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  19. Effect of the temperature and of the organic load in two-stage up flow anaerobic sludge blanket reactors treating of swine wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Bichuette, Alexandre Abud; Duda, Rose Maria; Oliveira, Roberto Alves de [Universidade Estadual Paulista (UNESP), Jaboticabal, SP (Brazil). Dept. de Engenharia Rural], E-mail: oliveira@fcav.unesp.br

    2008-07-01

    In this work the acting of two-stage up flow anaerobic sludge blanket reactors (UASB) was evaluated, installed in series, in pilot scale (volumes of 908 L and 350 L, respectively) in the treatment swine wastewater, with concentrations of total solids suspended (TSS) around 10000 mg L{sup -1}. The organic loading rates (OLR) applied in first UASB were of 5,2 and of 8,6 g total COD (Ld){sup -1}. The medium efficiencies of removal of the chemical demand of total oxygen (total COD), TSS and TKN were higher than 89; 80 and 55%, respectively, for the system of anaerobic treatment composed by the reactors UASB in two apprenticeships. The rate of volumetric methane production in the system of anaerobic treatment with the reactors UASB were 0,08 and 0,16 m{sup 3}CH{sub 4} (m{sup 3} CH{sub 4} reactor d){sup -1}. The number of total coliforms was reduced to 2,6x10{sup 4} NMP/100 mL. (author)

  20. Mixing characteristics and whey wastewater treatment of a novel moving anaerobic biofilm reactor.

    Science.gov (United States)

    Rodgers, Michael; Zhan, Xin-Min; Dolan, Brian

    2004-01-01

    A novel moving anaerobic biofilm reactor was used to treat whey wastewater. In this process, biofilm was grown on a plastic biofilm media module, which was vertically moved up and down in the bulk fluid. The objectives of the study were to investigate the mixing and performance characteristics of the new process in treating whey wastewater. The mixing efficiency was indicated by a dispersion number, D(L)/uL. D(L)/uL was up to 1.34, showing that the anaerobic reactor can be taken as a completely mixed reactor. At mesophilic conditions (35+/-2 degrees C), the admissible volumetric COD loading rate up to 11.6kg COD m(-3) day(-1) was achieved with the COD removal efficiency of 89% and the hydraulic retention time (HRT) of 1 day. When the HRT was 0.6 days, the volumetric COD loading rate was 15.2 kg COD m(-3) day(-1), but COD removal efficiency decreased to 81%. The percentage of methane (CH4) in the biogas was 63% on average and the yield of methane was 333.4 L CH4 kg(-1) COD removal at ambient conditions.

  1. Effect of temperature on two-phase anaerobic reactors treating slaughterhouse wastewater

    Directory of Open Access Journals (Sweden)

    Simone Beux

    2007-11-01

    Full Text Available The effectiveness of the anaerobic treatment of effluent from a swine and bovine slaughterhouse was assessed in two sets of two-phase anaerobic digesters, operated with or without temperature control. Set A, consisting of an acidogenic reactor with recirculation and an upflow biological filter as the methanogenic phase, was operated at room temperature, while set B, consisting of an acidogenic reactor without recirculation and an upflow biological filter as the methanogenic phase, was maintained at 32°C. The methanogenic reactors showed COD (Chemical Demand of Oxygen removal above 60% for HRT (Hydraulic Retention Time values of 20, 15, 10, 8, 6, 4, and 2 days. When the HRT value in those reactors was changed to 1 day, the COD percentage removal decreased to 50%. The temperature variations did not have harmful effects on the performance of reactors in set A.Avaliou-se a eficiência do tratamento anaeróbio de efluente de matadouro de suínos e bovinos em dois conjuntos de biodigestores anaeróbios de duas fases, operados com e sem controle de temperatura. O conjunto A, formado por um reator acidogênico com recirculação e um filtro biológico de fluxo ascendente, foi operado a temperatura ambiente e o conjunto B, formado por um reator de fluxo ascendente e um filtro biológico de fluxo ascendente, foi mantido a 32°C. Os reatores metanogênicos apresentaram remoção de DQO acima de 60 % para os TRHs de 20, 15, 10, oito, seis, quatro e dois dias. Quando o TRH destes reatores foi mudado para um dia observou-se uma queda da porcentagem de remoção de DQO para 50 %. As variações de temperatura parecem não ter prejudicado o desempenho dos reatores do conjunto A.

  2. Anaerobic digestion of dairy wastewater by inverse fluidization: the inverse fluidized bed and the inverse turbulent bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Buffiere, P.; Elmaleh, S.; Lebrato, J.; Moletta, R.

    2003-11-01

    This paper describes the application of the inverse fluidization technology to the anaerobic digestion of dairy wastewater. Two reactors were investigated: the inverse fluidized bed reactor and the inverse turbulent reactor. In these reactors, a granular floating solid is expanded by a down-flow current of effluent or an up-flow current of gas, respectively. The carrier particles (Extendospheres) were chosen for their large specific surface area (20,000 m{sup 2} m{sup -3}) and their low energy requirements for fluidization (gas velocity of 1.5 mm s{sup -1}, 5.4 m h{sup -1}). Organic load was increased stepwise by reducing hydraulic retention time from more than 60 days to 3 days, while maintaining constant the feed COD concentration. Both reactors achieved more than 90% of COD removal, at an organic loading rate of 10-12 kg{sub COD} m{sup -3} d{sup -1}, respectively. The performances observed were similar or even higher than that of other previously tested fluidized bed technologies treating the same wastewater. It was found that the main advantages of this system are: low energy requirement, because of the low fluidization velocities required; there is no need of a settling device, because solids accumulate at the bottom of the reactor, so they can be easily drawn out and particles with high-biomass content can be easily recovered. Lipid phosphate concentration has been revealed as a good method for biomass estimation in biofilms since it only includes living biomass. (Author)

  3. ATP as an indicator of biomass activity in thermophilic upflow anaerobic sludge blanket reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This work investigated the biomass activity in a thermophilic upflow anaerobic sludge blanket (UASB) reactor of wastewater treatment. Synthetic textile wastewater with pH 10-11, COD level of 2000-3000 mg/L was tested. Cellular adenosine triphosphate (ATP) in volatile solids (VS; mg ATP/gVS) was measured and expressed as specific ATP content to compare the biomass activity in up zone and lower zone in UASB reactor. The result shows that the specific ATP content based on total volatile solids (VS)in lower zone (0. 046 mgATP/gVS average) is much lower than that in up zone (0.62 mgATP/gVS average) due to high content of inactive biomass and high pH in lower zone. The SATP in up zone increases as HRT increases and approaches to a maximum value of 0.85 mgATP/gVS at HRT of 7h, then decreases. It shows most of the total VS in up zone represent active bacterial biomass at HRT of 7h. Rate of subtract utilization is directly related to the activity of microorganisms in the reactor. The effect of HRT on SATP in lower zone is not as significant as on SATP in up zone. The buffer capacity of the thermophilic UASB reactor is very good. It is the activity of sludge granules in lower zone that give the UASB reactor such a good buffer capacity to the inlet high pH.

  4. Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions.

    Science.gov (United States)

    Mogensen, A S; Ahring, B K

    2002-03-05

    Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 micromol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon atoms. The reactor was operated with a hydraulic retention time of 12 h with effluent recirculation in an effluent to influent ratio of 5 to 1. A sterile reactor operated in parallel revealed that sorption to sludge particles initially accounted for a major LAS removal. After 8 days of reactor operation, the removal of LAS in the reactor inoculated with active granular biomass exceeded the removal in the sterile reactor inoculated with sterile granular biomass. The effect of sorption ceased after 185 to 555 h depending on the LAS homologs. 40% of the LAS was biodegraded, and the removal rate was 0.5 x 10(-6) mol/h/mL granular biomass. Acidified effluent from the reactor was subjected to dichloromethane extraction followed by gas chromatography/mass spectrometry. Benzenesulfonic acid and benzaldehyde were detected in the reactor effluent from the reactor with active granular biomass but not in the sterile and unamended reactor effluent. Benzenesulfonic acid and benzaldehyde are the first identified degradation products in the anaerobic degradation of LAS.

  5. Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture.

    Science.gov (United States)

    Luo, Gang; Angelidaki, Irini

    2012-11-01

    Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO(2) , biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO(2) to CH(4) by addition of H(2) . Enrichment at thermophilic temperature (55°C) resulted in CO(2) and H(2) bioconversion rate of 320 mL CH(4) /(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed by PCR-DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree of biogas upgrading was achieved. The produced biogas had a CH(4) content, around 95% at steady-state, at gas (mixture of biogas and hydrogen) injection rate of 6 L/(L day). The increase of gas injection rate to 12 L/(L day) resulted in the decrease of CH(4) content to around 90%. Further study showed that by decreasing the gas-liquid mass transfer by increasing the stirring speed of the mixture the CH(4) content was increased to around 95%. Finally, the CH(4) content around 90% was achieved in this study with the gas injection rate as high as 24 L/(L day).

  6. Biological treatment of anaerobically digested palm oil mill effluent (POME) using a Lab-Scale Sequencing Batch Reactor (SBR).

    Science.gov (United States)

    Chan, Yi Jing; Chong, Mei Fong; Law, Chung Lim

    2010-08-01

    The production of highly polluting palm oil mill effluent (POME) has resulted in serious environmental hazards. While anaerobic digestion is widely accepted as an effective method for the treatment of POME, anaerobic treatment of POME alone has difficulty meeting discharge limits due to the high organic strength of POME. Hence, subsequent post-treatment following aerobic treatment is vital to meet the discharge limits. The objective of the present study is to investigate the aerobic treatment of anaerobically digested POME by using a sequencing batch reactor (SBR). The SBR performance was assessed by measuring Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) removal as well as Sludge Volume Index (SVI). The operating pH and dissolved oxygen concentrations were found to be 8.25-9.14 and 1.5-6.4 mg/L, respectively, throughout the experiment. The experimental results demonstrate that MLVSS, OLR and sludge loading rate (SLR) play a significant role in the organic removal efficiency of SBR systems and therefore, further investigation on these parameters was conducted to attain optimum SBR performance. Maximum COD (95-96%), BOD (97-98%) and TSS (98-99%) removal efficiencies were achieved at optimum OLR, SLR and MLVSS concentration ranges of 1.8-4.2 kg COD/m(3)day, 2.5-4.6 kg TSS/m(3)day and 22,000-25,000 mg/L, respectively. The effluent quality remained stable and complied with the discharge limit. At the same time, the sludge showed good settling properties with average SVI of 65. It is envisaged that the SBR process could complement the anaerobic treatment to produce final treated effluent which meets the discharge limit.

  7. Biodegradation kinetics during different start up of the anaerobic tapered fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    Rangasamy Parthiban

    2011-10-01

    Full Text Available Kinetic study for different start up conditions of the anaerobic digestion of wastewater derived from the sago processingfrom tubers of tapioca (Mannihot utillisema is discussed. The experiment is carried out with synthetic waste water usinga tapered fluidized bed reactor. Mesoporous granulated activated carbon is used as a bacterial support. The kinetic modelfollows half order kinetics for substrate utilization and for methane formation and it exhibits an order of 0.20 during thestart up of the reactor without acclimatization. For the remaining start up with acclimatized sludge, kinetic parameters areexpressed in terms of Langmuir-Hinshelwood kinetics for the substrate utilization. The methane formation kinetics followsan order of the reaction as 0.30. The values of the kinetic constants are in the range of 0.13–0.21.

  8. [Characteristics of anaerobic sequencing batch reactor for the treatment of high-solids-content waste].

    Science.gov (United States)

    Wang, Zhi-jun; Wang, Wei; Zhang, Xi-hui

    2006-06-01

    Based on the experiments of digestion of thermo-hydrolyzed sewage sludge in both mesophilic and thermophilic anaerobic sequencing batch reactors (ASBRs) with 20, 10, 7.5, 5d hydraulic retention time (HRT), operating characteristics of ASBR for treatment of high-solids-content waste were investigated. ASBR can efficiently accumulates suspended solids and keep high concentration solids, however there exists a "critical point" of ASBR, which means the maximum capability to accumulate suspended solids without negative effects on ASBR stability, and beyond which the performance deteriorates. Under steady condition, ASBR can sustains high solid retention time (SRT) and mean cell retention time (MCRT), the SRT and MCRT is 2.53 approximately 3.73 and 2.03 approximately 3.14 times of hydraulic retention time (HRT) when treating thermo-hydrolyzed sludge, respectively. Therefore, compared to traditional continuous-flow stirred tank reactor (CSTR), the efficiency of ASBR enhances about 7.13% approximately 34.68%.

  9. Computer-aided design model for anaerobic-phased-solids digester system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.; Zhang, R. [University of California, Davis, CA (United States); Tiangco, V. [California Energy Commission, Sacramento, CA (United States)

    1999-07-01

    The anaerobic-phased-solids (APS) digester system is a newly developed anaerobic digestion system for converting solid wastes, such as crop residues and food wastes, into biogas for power and heat generation. A computer-aided engineering design model has been developed to design the APS-digester system and study the heat transfer from the reactors and energy production of the system. Simulation results of a case study are presented by using the model to predict the heating energy requirement and biogas energy production for anaerobic digestion of garlic waste. The important factors, such as environmental conditions, insulation properties, and characteristics of the wastes, on net energy production are also investigated. (author)

  10. Kinetic analysis of microbial sulfate reduction by desulfovibrio desulfuricans in an anaerobic upflow porous media biofilm reactor.

    Science.gov (United States)

    Chen, C I; Mueller, R F; Griebe, T

    1994-02-20

    An anaerobic upflow porous media biofilm reactor was designed to study the kinetics and stoichiometry of hydrogen sulfide production by the sulfate-reducing bacterium (SRB) Desulfovibrio desulfuricans (ATCC 5575) as the first step for the modeling and control of formation souring (H(2)S) in oil field porous media. The reactor was a packed bed (50 x 5.5 cm) tubular reactor. Sea sand (140 to 375 mum) was used as the porous media. The initial indication of souring was the appearance of well-separated black spots (precipitates of iron sulfide) in the sand bed. The blackened zones expanded radially and upward through the column. New spots also appeared and expanded into the cone shapes. Lactate (substrate) was depleted and hydrogen sulfide appeared in the effluent.Analysis of the pseudo-steady state column shows that there were concentration gradients for lactate and hydrogen sulfide along the column. The results indicate that most of the lactate was consumed at the front part of the column. Measurements of SRB biomass on the solid phase (sand) and in the liquid phase indicate that the maximum concentration of SRB biomass resided at the front part of the column while the maximum in the liquid phase occurred further downstream. The stoichiometry regarding lactate consumption and hydrogen sulfide production observed in the porous media reactor was different from that in a chemostat. After analyzing the radial dispersion coefficient for the SRB in porous media and kinetics of microbial growth, it was deduced that transport phenomena dominate the souring process in our porous media reactor system. (c) 1994 John Wiley & Sons, Inc.

  11. Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Liao Dexiang; Li Xiaoming; Yang Qi; Zeng Guangming; Guo Liang; Yue Xiu

    2008-01-01

    The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon (sodium bicarbonate) on anaerobic ammonium oxidation. The enrichment of anammox bacteria was carried out in a 7.0-L SBR and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR. Research results , especially the biomass, showed first signs of anammox activity after 54 d cultivation with synthetic wastewater, when the pH was controlled between 7.5 and 8.3, the temperature was 35℃. The anammox activity increased as the influent bicarbonate concentration increased from 1.0 to 1.5 g/L and then, was inhibited as the bicarbonate concentration approached 2.0 g/L. However, the activity could be restored by the reduction of bicarbonate concentration to 1.0 g/L, as shown by rapid conversion of ammonium, and nitrite and nitrate production with normal stoichiometry. The optimization of the bicarbonate concentration in the reactor could increase the anammox rate up to 66.4 mgN/(L·d).

  12. Biological Phosphorus Release and Uptake Under Alternating Anaerobic and Anoxic Conditions In a Fixed-Film Reactor

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens; Strube, Rune

    1994-01-01

    Biological phosphorus removal was investigated in a fixed-film reactor with alternating anaerobic and anoxic conditions. The tests showed that biological phosphorus removal can be obtained in a fixed-film reactor with nitrate as oxidising agent. In the anaerobic period, 0.52 mg of PO4-P...... potassium taken up and phosphate taken up in the anoxic phase was determined to be 0.36 mg K/mg P. The phosphorus concentration in the sludge was determined at 8–10% of dry solids....

  13. Performance evaluation of cigarette filter rods as a biofilm carrier in an anaerobic moving bed biofilm reactor.

    Science.gov (United States)

    Sabzali, Ahmad; Nikaeen, Mahnaz; Bina, Bijan

    2012-01-01

    Biocarriers are an important component of anaerobic moving bed biofilm reactors (AMBBRs). In this study, the capability of cigarette filter rods (CFRs) as a biocarrier in an anaerobic moving bed biofilm reactor was evaluated. Two similar lab-scale anaerobic moving bed biofilm reactors were undertaken using Kaldnes-K3 plastic media and cigarette filter rods (wasted filters from tobacco factories) as biofilm attachment media for wastewater treatment. Organic substance and total posphours (TP) removal was investigated over 100 days. Synthetic wastewater was prepared with ordinary water and glucose as the main sources of carbon and energy, plus balanced macro- and micro-nutrients. Process performance was studied by increasing the organic loading rate (OLR) in the range of 1.6-4.5 kg COD/m3 x d. The COD average removal efficiency were 61.3% and 64.5% for AMBBR with cigarette filter rods (Reactor A) and AMBBR with Kaldnes plastic media (Reactor B), respectively. The results demonstrate that the performance of the AMBBR containing 0.25 litres of cigarette filters was comparable with a similar reactor containing 1.5 litres of Kaldnes plastic media. An average phosphorus removal of 67.7% and 72.9% was achieved by Reactors A and B, respectively.

  14. Sulfamethoxazole and ciprofloxacin removal using a horizontal-flow anaerobic immobilized biomass reactor.

    Science.gov (United States)

    Chatila, Sami; Amparo, Maura R; Carvalho, Lucas S; Penteado, Eduardo D; Tomita, Inês N; Santos-Neto, Álvaro J; Lima Gomes, Paulo C F; Zaiat, Marcelo

    2016-01-01

    The antibiotics sulfamethoxazole (SMTX) and ciprofloxacin (CIP) are commonly used in human and veterinary medicine, which explains their occurrence in wastewater. Anaerobic reactors are low-cost, simple and suitable technology to wastewater treatment, but there is a lack of studies related to the removal efficiency of antibiotics. To overcome this knowledge gap, the objective of this study was to evaluate the removal kinetics of SMTX and CIP using a horizontal-flow anaerobic immobilized biomass reactor. Two different concentrations were evaluated, for SMTX 20 and 40 μg L(-1); for CIP 2.0 and 5.0 μg L(-1). The affluent and effluent analysis was carried out in liquid chromatography/tandem mass spectrometry (LC-MS/MS) with the sample preparation procedure using an off-line solid-phase extraction. This method was developed, validated and successfully applied for monitoring the affluent and effluent samples. The removal efficiency found for both antibiotics at the two concentrations studied was 97%. Chemical oxygen demand (COD) exhibited kinetic constants that were different from that observed for the antibiotics, indicating the absence of co-metabolism. Also, though the antibiotic concentration was increased, there was no inhibitory effect in the removal of COD and antibiotics.

  15. Innovative bioelectrochemical-anaerobic-digestion integrated system for ammonia recovery and bioenergy production from ammonia-rich residues

    OpenAIRE

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production (Figure 1). In batch experiment, th...

  16. Plasma reactor waste management systems

    Science.gov (United States)

    Ness, Robert O., Jr.; Rindt, John R.; Ness, Sumitra R.

    1992-01-01

    The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems.

  17. Application of IC Anaerobic Reactor in Wastewater Treatment%内循环(IC)厌氧反应器在废水处理中的应用

    Institute of Scientific and Technical Information of China (English)

    钟启俊

    2014-01-01

    The paper introduces the basic principle of inner circulating (IC) anaerobic reactor, analyzes the technology characteristic of IC anaerobic reactor, namely IC anaerobic reactor is an anaerobic reactor with new type and high efifciency, and explains the application development and prospect of the IC anaerobic reactor in wastewater treatment.%介绍了内循环(IC)厌氧反应器的基本原理,分析了IC厌氧反应器的工艺特点,即IC厌氧反应器是新型高效厌氧生物反应器,扼述了IC厌氧反应器在废水处理中的应用进展及前景。

  18. Performance of an Anaerobic Baffled Filter Reactor in the Treatment of Algae-Laden Water and the Contribution of Granular Sludge

    OpenAIRE

    Yaqin Yu; Xiwu Lu; Yifeng Wu

    2014-01-01

    This study investigated the performance and stability of an anaerobic baffled filter reactor in the treatment of algae-laden water from Taihu Lake at several organic loading rates. The study also evaluated the capability of soft filler to train granule sludge and improve the anaerobic environment and sludge activity in the anaerobic baffled reactor (ABR), thereby enhancing the treatment efficiency. The ABR consisted of five rectangular compartments, each of which was 120 cm long, 80 cm wide, ...

  19. Anaerobic digestion of hemicellulose hydrolysate produced after hydrothermal pretreatment of sugarcane bagasse in UASB reactor.

    Science.gov (United States)

    Ribeiro, Fernanda Resende; Passos, Fabiana; Gurgel, Leandro Vinícius Alves; Baêta, Bruno Eduardo Lobo; de Aquino, Sérgio Francisco

    2017-04-15

    In the context of a sugarcane biorefinery, sugarcane bagasse produced may be pretreated generating a solid and liquid fraction. The solid fraction may be used for 2G bioethanol production, while the liquid fraction may be used to produce biogas through anaerobic digestion. The aim of this study consisted in evaluating the anaerobic digestion performance of hemicellulose hydrolysate produced after hydrothermal pretreatment of sugarcane bagasse. For this, hydrothermal pretreatment was assessed in a continuous upflow anaerobic sludge blanket (UASB) reactor operated at a hydraulic retention time (HRT) of 18.4h. Process performance was investigated by varying the dilution of sugarcane bagasse hydrolysate with a solution containing xylose and the inlet organic loading rate (OLR). Experimental data showed that an increase in the proportion of hydrolysate in the feed resulted in better process performance for steps using 50% and 100% of real substrate. The best performance condition was achieved when increasing the organic loading rate (OLR) from 1.2 to 2.4gCOD/L·d, with an organic matter removal of 85.7%. During this period, the methane yield estimated by the COD removal would be 270LCH4/kg COD. Nonetheless, when further increasing the OLR to 4.8gCOD/L·d, the COD removal decreased to 74%, together with an increase in effluent concentrations of VFA (0.80gCOD/L) and furans (115.3mg/L), which might have inhibited the process performance. On the whole, the results showed that anaerobic digestion of sugarcane bagasse hydrolysate was feasible and may improve the net energy generation in a bioethanol plant, while enabling utilization of the surplus sugarcane bagasse in a sustainable manner.

  20. Improvement of hydrogen production via ethanol-type fermentation in an anaerobic down-flow structured bed reactor.

    Science.gov (United States)

    Anzola-Rojas, Mélida del Pilar; Zaiat, Marcelo; De Wever, Heleen

    2016-02-01

    Although a novel anaerobic down-flow structured bed reactor has shown feasibility and stable performance for a long-term compared to other anaerobic fixed bed systems for continuous hydrogen production, the volumetric rates and yields have so far been too low. In order to improve the performance, an operation strategy was applied by organic loading rate (OLR) variation (12-96 g COD L(-1) d(-1)). Different volumetric hydrogen rates, and yields at the same OLR indicated that the system was mainly driven by the specific organic load (SOL). When SOL was kept between 3.8 and 6.2 g sucrose g(-1) VSS d(-1), the volumetric rates raised from 0.1 to 8.9 L H2 L(-1) d(-1), and the yields were stable around 2.0 mol H2 mol(-1) converted sucrose. Furthermore, hydrogen was produced mainly via ethanol-type fermentation, reaching a total energy conversion rate of 23.40 kJ h(-1) L(-1) based on both hydrogen and ethanol production.

  1. Nitrate removal by organotrophic anaerobic ammonium oxidizing bacteria with C2/C3 fatty acid in upflow anaerobic sludge blanket reactors.

    Science.gov (United States)

    Liang, Yuhai; Li, Dong; Zhang, Xiaojing; Zeng, Huiping; Yang, Yin; Zhang, Jie

    2015-10-01

    In anaerobic ammonium oxidation (Anammox) process, a harsh ratio of nitrite to ammonia in influent was demanded, and the max nitrogen removal efficiency could only achieve to 89%, both of which limited the development of Anammox. The aim of this work was to study the nitrate removal by organotrophic anaerobic ammonium oxidizing bacteria (AAOB) with C2/C3 fatty acid in upflow anaerobic sludge blanket (UASB) reactors. In this study, organotrophic AAOB was successfully enriched by adding acetate and propionate with the total organic carbon to nitrogen (TOC/N) ratio of 0.1. In the condition of low substrate, the TN removal efficiency reached 90%, with the effluent TN of around 11.8 mg L(-1). After the addition of acetate and propionate, the predominant species in Anammox granular sludge transformed to Candidatus Jettenia that belonging to organotrophic AAOB from the Candidatus Kuenenia relating to general AAOB.

  2. Steady performance of a zero valent iron packed anaerobic reactor for azo dye wastewater treatment under variable influent quality

    Institute of Scientific and Technical Information of China (English)

    Yaobin Zhang; Yiwen Liu; Yanwen Jing; Zhiqiang Zhao; Xie Quan

    2012-01-01

    Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment.Based on this idea,a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality.The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI.The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV.Iron ion dissolution from the ZVI could buffer acidity in the reactor,the amount of which was related to the COD concentration.Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one.Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.

  3. Steady performance of a zero valent iron packed anaerobic reactor for azo dye wastewater treatment under variable influent quality.

    Science.gov (United States)

    Zhang, Yaobin; Liu, Yiwen; Jing, Yanwen; Zhao, Zhiqiang; Quan, Xie

    2012-01-01

    Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment. Based on this idea, a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality. The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI. The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV. Iron ion dissolution from the ZVI could buffer acidity in the reactor, the amount of which was related to the COD concentration. Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one. Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.

  4. Modelling of slaughterhouse solid waste anaerobic digestion: determination of parameters and continuous reactor simulation.

    Science.gov (United States)

    López, Iván; Borzacconi, Liliana

    2010-10-01

    A model based on the work of Angelidaki et al. (1993) was applied to simulate the anaerobic biodegradation of ruminal contents. In this study, two fractions of solids with different biodegradation rates were considered. A first-order kinetic was used for the easily biodegradable fraction and a kinetic expression that is function of the extracellular enzyme concentration was used for the slowly biodegradable fraction. Batch experiments were performed to obtain an accumulated methane curve that was then used to obtain the model parameters. For this determination, a methodology derived from the "multiple-shooting" method was successfully used. Monte Carlo simulations allowed a confidence range to be obtained for each parameter. Simulations of a continuous reactor were performed using the optimal set of model parameters. The final steady-states were determined as functions of the operational conditions (solids load and residence time). The simulations showed that methane flow peaked at a flow rate of 0.5-0.8 Nm(3)/d/m(reactor)(3) at a residence time of 10-20 days. Simulations allow the adequate selection of operating conditions of a continuous reactor.

  5. Simultaneous Coproduction of Hydrogen and Ethanol in Anaerobic Packed-Bed Reactors

    Directory of Open Access Journals (Sweden)

    Cristiane Marques dos Reis

    2014-01-01

    Full Text Available This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT (1–8 h. Two reactors filled with expanded clay and fed with glucose (3136–3875 mg L−1 were operated at different total upflow velocities: 0.30 cm s−1 (R030 and 0.60 cm s−1 (R060. The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3 and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h−1 L−1 in R030 at HRT of 1 h. Furthermore, the highest hydrogen yield of 2.39 mol H2 mol−1 glucose was obtained in R060. No clear trend was observed by doubling the upflow velocities at this experiment. High ethanol production was also observed, indicating that the ethanol-pathway prevailed throughout the experiment.

  6. Simultaneous coproduction of hydrogen and ethanol in anaerobic packed-bed reactors.

    Science.gov (United States)

    dos Reis, Cristiane Marques; Silva, Edson Luiz

    2014-01-01

    This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT) (1-8 h). Two reactors filled with expanded clay and fed with glucose (3136-3875 mg L(-1)) were operated at different total upflow velocities: 0.30 cm s(-1) (R030) and 0.60 cm s(-1) (R060). The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3 and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h(-1) L(-1) in R030 at HRT of 1 h. Furthermore, the highest hydrogen yield of 2.39 mol H2 mol(-1) glucose was obtained in R060. No clear trend was observed by doubling the upflow velocities at this experiment. High ethanol production was also observed, indicating that the ethanol-pathway prevailed throughout the experiment.

  7. Anaerobic degradation of linear alkylbenzene sulfonate (LAS) in fluidized bed reactor by microbial consortia in different support materials.

    Science.gov (United States)

    de Oliveira, Lorena Lima; Costa, Rachel Biancalana; Okada, Dagoberto Yukio; Vich, Daniele Vital; Duarte, Iolanda Cristina Silveira; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2010-07-01

    Four anaerobic fluidized bed reactors filled with activated carbon (R1), expanded clay (R2), glass beads (R3) and sand (R4) were tested for anaerobic degradation of LAS. All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with approximately 20 mg l(-1) of LAS, on average. To 560 mg l(-1) COD influent, the maximum COD and LAS removal efficiencies were mean values of 97+/-2% and 99+/-2%, respectively, to all reactors demonstrating the potential applicability of this reactor configuration for treating LAS. The reactors were kept at 30 degrees C and operated with a hydraulic retention time (HRT) of 18h. The use of glass beads and sand appear attractive because they favor the development of biofilms capable of supporting LAS degradation. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of samples from reactors R3 and R4 revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria, indicating the role of microbial consortia in degrading the surfactant LAS.

  8. Simultaneous enrichment of denitrifying anaerobic methane-oxidizing microorganisms and anammox bacteria in a hollow-fiber membrane biofilm reactor.

    Science.gov (United States)

    Ding, Zhao-Wei; Lu, Yong-Ze; Fu, Liang; Ding, Jing; Zeng, Raymond J

    2017-01-01

    In this study, the coculture system of denitrifying anaerobic methane oxidation (DAMO) microbes and anaerobic ammonium oxidation (anammox) bacteria was successfully enriched in a hollow-fiber membrane biofilm reactor (HfMBR) using freshwater sediment as the inoculum. The maximal removal rates of nitrate and ammonium were 78 mg N/L/day (131 mg N/m(2)/day) and 26 mg N/L/day (43 mg N/m(2)/day), respectively. Due to the high rate of methane mass transfer in HfMBR, the activity of DAMO archaea continued to increase during the enrichment period, indicating that HfMBR could be a powerful tool to enrich DAMO microorganisms. Effects of partial methane pressure, temperature, and pH on the cocultures were obvious. However, the microbial activity in HfMBR could be recovered quickly after the shock change of environmental factors. Furthermore, the result also found that DAMO bacteria likely had a stronger competitive advantage than anammox bacteria under the operating conditions in this study. High-throughput sequencing 16S rRNA genes illustrated that the dominant microbes were NC10, Euryarchaeota, Proteobacteria, Planctomycetes, and Chlorobi with relative abundance of 38.8, 26.2, 13.78, 6.2, and 3.6 %, respectively.

  9. Fermentative hydrogen production from beet sugar factory wastewater treatment in a continuous stirred tank reactor using anaerobic mixed consortia

    Institute of Scientific and Technical Information of China (English)

    Gefu ZHU; Chaoxiang LIU; Jianzheng LI; Nanqi REN; Lin LIU; Xu HUANG

    2013-01-01

    A low pH, ethanol-type fermentation process was evaluated for wastewater treatment and bio-hydrogen production from acidic beet sugar factory wastewater in a continuous stirred tank reactor (CSTR) with an effective volume of 9.6 L by anaerobic mixed cultures in this present study. After inoculating with aerobic activated sludge and operating at organic loading rate (OLR) of 12 kgCOD·m-3·d-1, HRT of 8h, and temperature of 35℃ for 28 days, the CSTR achieved stable ethanol-type fermentation. When OLR was further increased to 18 kgCOD·m-3·d-1, on the 53rd day, ethanol-type fermentation dominant microflora was enhanced. The liquid fermentation products, including volatile fatty acids (VFAs) and ethanol, stabilized at 1493mg·L-1 in the bioreactor. Effluent pH, oxidation-reduction potential (ORP), and alkalinity ranged at 4.1-4.5, -250-(-290) mV, and 230-260mgCaCO3·L-1. The specific hydrogen production rate of anaerobic activated sludge was 0.1 L'gMLVSS-1· d-1 and the COD removal efficiency was 45%. The experimental results showed that the CSTR system had good operation stability and microbial activity, which led to high substrate conversion rate and hydrogen production ability.

  10. Bacterial community dynamics in a swine wastewater anaerobic reactor revealed by 16S rDNA sequence analysis.

    Science.gov (United States)

    Liu, An-Chi; Chou, Chu-Yang; Chen, Ling-Ling; Kuo, Chih-Horng

    2015-01-20

    Anaerobic digestion is a microbiological process of converting organic wastes into digestate and biogas in the absence of oxygen. In practice, disturbance to the system (e.g., organic shock loading) may cause imbalance of the microbial community and lead to digester failure. To examine the bacterial community dynamics after a disturbance, this study simulated an organic shock loading that doubled the chemical oxygen demand (COD) loading using a 4.5L swine wastewater anaerobic completely stirred tank reactor (CSTR). Before the shock (loading rate=0.65gCOD/L/day), biogas production rate was about 1-2L/L/day. After the shock, three periods representing increased biogas production rates were observed during days 1-7 (∼4.0L/L/day), 13 (3.3L/L/day), and 21-23 (∼6.1L/L/day). For culture-independent assessments of the bacterial community composition, the 454 pyrosequencing results indicated that the community contained >2500 operational taxonomic units (OTUs) and was dominated by three phyla: Bacteroidetes, Firmicutes, and Proteobacteria. The shock induced dynamic changes in the community composition, which was re-stabilized after approximately threefold hydraulic retention time (HRT). Intriguingly, upon restabilization, the community composition became similar to that observed before the shock, rather than reaching a new equilibrium.

  11. Biogas production in an anaerobic sequencing batch reactor by using tequila vinasses: effect of pH and temperature.

    Science.gov (United States)

    Arreola-Vargas, J; Jaramillo-Gante, N E; Celis, L B; Corona-González, R I; González-Álvarez, V; Méndez-Acosta, H O

    2016-01-01

    In recent years, anaerobic digestion has been recognized as a suitable alternative for tequila vinasses treatment due to its high energy recovery and chemical oxygen demand (COD) removal efficiency. However, key factors such as the lack of suitable monitoring schemes and the presence of load disturbances, which may induce unstable operating conditions in continuous systems, have limited its application at full scale. Therefore, the aim of this work was to evaluate the anaerobic sequencing batch reactor (AnSBR) configuration in order to provide a low cost and easy operation alternative for the treatment of these complex effluents. In particular, the AnSBR was evaluated under different pH-temperature combinations: 7 and 32 °C; 7 and 38 °C; 8 and 32 °C and 8 and 38 °C. Results showed that the AnSBR configuration was able to achieve high COD removal efficiencies (around 85%) for all the tested conditions, while the highest methane yield was obtained at pH 7 and 38 °C (0.29 L/g COD added). Furthermore, high robustness was found in all the AnSBR experiments. Therefore, the full-scale application of the AnSBR technology for the treatment of tequila vinasses is quite encouraging, in particular for small and medium size tequila industries that operate under seasonal conditions.

  12. Transformation of carbon tetrachloride in an anaerobic packed-bed reactor without addition of another electron donor

    NARCIS (Netherlands)

    Best, J.H. de; Hunneman, P.; Doddema, H.J.; Janssen, D.B.; Harder, W.

    1999-01-01

    Carbon tetrachloride (52 μM) was biodegraded for more than 72% in an anaerobic packed-bed reactor without addition of an external electron donor. The chloride mass balance demonstrated that all carbon tetrachloride transformed was completely dechlorinated. Chloroform and dichloromethane were sometim

  13. Effects of phosphate addition on methane fermentation in the batch and upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Suzuki, Sho; Shintani, Masaki; Sanchez, Zoe Kuizon; Kimura, Kohei; Numata, Mitsuru; Yamazoe, Atsushi; Kimbara, Kazuhide

    2015-12-01

    Ammonia inhibition of methane fermentation is one of the leading causes of failure of anaerobic digestion reactors. In a batch anaerobic digestion reactor with 429 mM NH3-N/L of ammonia, the addition of 25 mM phosphate resulted in an increase in methane production rate. Similar results were obtained with the addition of disodium phosphate in continuous anaerobic digestion using an upflow anaerobic sludge blanket (UASB) reactor. While methane content and production rate decreased in the presence of more than 143 mM NH3-N/L of ammonium chloride in UASB, the addition of 5 mM disodium phosphate suppressed ammonia inhibition at 214 mM NH3-N/L of ammonium chloride. The addition prevented acetate/propionate accumulation, which might be one of the effects of the phosphate on the ammonia inhibition. The effects on the microbial community in the UASB reactor was also assessed, which was composed of Bacteria involved in hydrolysis, acidogenesis, acetogenesis, and dehydrogenation, as well as Archaea carrying out methanogenesis. The change in the microbial community was observed by ammonia inhibition and the addition of phosphate. The change indicates that the suppression of ammonia inhibition by disodium phosphate addition could stimulate the activity of methanogens, reduce shift in bacterial community, and enhance hydrogen-producing bacteria. The addition of phosphate will be an important treatment for future studies of methane fermentation.

  14. Transformation of carbon tetrachloride in an anaerobic packed-bed reactor without addition of another electron donor

    NARCIS (Netherlands)

    de Best, JH; Hunneman, P; Doddema, HJ; Janssen, DB; Harder, W; Doddema, Hans J.

    1999-01-01

    Carbon tetrachloride (52 mu M) was biodegraded for more than 72% in an anaerobic packed-bed reactor without addition of an external electron donor. The chloride mass balance demonstrated that all carbon tetrachloride transformed was completely dechlorinated. Chloroform and dichloromethane were somet

  15. Degradation of Methanethiol by Methylotrophic Methanogenic Archaea in a Lab-Scale Upflow Anaerobic Sludge Blanket Reactor

    NARCIS (Netherlands)

    Bok, de F.A.M.; Leerdam, van R.C.; Lomans, B.P.; Smidt, H.; Lens, P.N.L.; Janssen, A.J.H.; Stams, A.J.M.

    2006-01-01

    In a lab-scale upflow anaerobic sludge blanket reactor inoculated with granular sludge from a full-scale wastewater treatment plant treating paper mill wastewater, methanethiol (MT) was degraded at 30°C to H2S, CO2, and CH4. At a hydraulic retention time of 9 h, a maximum influent concentration of 6

  16. Stimulation of Methanol Degradation in UASB Reactors: In Situ Versus Pre-Loading Cobalt on Anaerobic Granular Sludge

    NARCIS (Netherlands)

    Zandvoort, M.H.; Gieteling, J.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    The effect of pre-loading and in situ loading of cobalt onto a cobalt-limited granular sludge on the performance of methanol fed bioreactors was investigated. One upflow anaerobic sludge bed (UASB) reactor was inoculated with cobalt pre-loaded sludge (24h; 30degreesC; 1 mM CoCl2) and a second UASB w

  17. Operational strategies for thermophilic anaerobic digestion of organic fraction of municipal solid waste in continuously stirred tank reactors

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Cui, J.; Chen, X.;

    2006-01-01

    Three operational strategies to reduce inhibition due to ammonia during thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste (SS-OFMSW) rich in proteins were investigated. Feed was prepared by diluting SS-OFMSW (ratio of 1:4) with tap water or reactor proces...

  18. Modelling the rheological properties of sludge during anaerobic digestion in a batch reactor by using electrical measurements.

    Science.gov (United States)

    Dieudé-Fauvel, E; Héritier, P; Chanet, M; Girault, R; Pastorelli, D; Guibelin, E; Baudez, J C

    2014-03-15

    Anaerobic digestion is a significant process leading to biogas production and waste management. Despite this double interest, professionals still face a lack of efficient tools to monitor and manage the whole procedure. This is especially true for rheological properties of the material inside the reactor, which are of major importance for anaerobic digestion management. However, rheological properties can hardly be determined in-situ and it would be very helpful to determine indicators of their evolution. To solve this problem, this paper investigates the evolution of sewage sludge rheological and electrical properties during the anaerobic digestion in a batch reactor. We especially focus on apparent viscosity and complex impedance, measured by electrical impedance spectroscopy. Both of them can be modelled by a linear combination of raw sludge and inoculum properties, weighted by time-dependent coefficients. Thus, by determining digested sludge electrical signature, it is possible to obtain those coefficients and model sludge apparent viscosity. This work offers many theoretical and practical prospects.

  19. Production of bio-hydrogen by mesophilic anaerobic fermentation in an acid-phase sequencing batch reactor.

    Science.gov (United States)

    Cheong, Dae-Yeol; Hansen, Conly L; Stevens, David K

    2007-02-15

    The pH and hydraulic retention time (HRT) of an anaerobic sequencing batch reactor (ASBR) were varied to optimize the conversion of carbohydrate-rich synthetic wastewater into bio-hydrogen. A full factorial design using evolutionary operation (EVOP) was used to determine the effect of the factors and to find the optimum condition of each factor required for high hydrogen production rate. Experimental results from 20 runs indicate that a maximum hydrogen production rate of 4,460-5,540 mL/L/day under the volumetric organic loading rate (VOLR) of 75 g-COD/L/day obtained at an observed design point of HRT = 8 h and pH = 5.7. The hydrogen production rate was strongly dependent on the HRT, and the effect was statistically significant (P 0.05) was found for the pH on the hydrogen production rate. When the ASBR conditions were set for a maximum hydrogen production rate, the hydrogen production yield and specific hydrogen production rate were 60-74 mL/g-COD and 330-360 mL/g-VSS/day, respectively. The hydrogen composition was 43-51%, and no methanogenesis was observed. Acetate, propionate, butyrate, valerate, caproate, and ethanol were major liquid intermediate metabolites during runs of this ASBR. The dominant fermentative types were butyrate-acetate or ethanol-acetate, representing the typical anaerobic pathway of Clostridium species. This hydrogen-producing ASBR had a higher hydrogen production rate, compared with that produced using continuous-flow stirred tank reactors (CSTRs). This study suggests that the hydrogen-producing ASBR is a promising bio-system for prolonged and stable hydrogen production.

  20. Relationships between anaerobic consortia and removal efficiencies in an UASB reactor degrading 2,4 dichlorophenol (DCP).

    Science.gov (United States)

    Sponza, Delia Teresa; Cigal, Canan

    2008-04-01

    To gain more insight into the interactions between anaerobic bacteria and reactor performances (chemical oxygen demand-COD, 2,4 dichlorophenol-2,4 DCP removals, volatile fatty acid-VFA, and methane gas productions) and how they depended on operational conditions the microbial variations in the anaerobic granular sludge from an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 DCP was studied. The study was composed of two parts. In the first part, the numbers of methanogens and acedogens in the anaerobic granular sludge were counted at different COD removal efficiencies. The relationships between the numbers of methanogens, the methane gas production and VFA production were investigated. The COD removal efficiencies increased to 74% from 30% while the number of total acedogens decreased to 10 from 30 cfu ml(-1). The number of total methanogens and acedogens varied between 11 x 10(3) and 10 x 10(9)MPN g(-1) and 10 and 30 cfu ml(-1) as the 2,4 DCP removal efficiencies were obtained between 60% and 99%, respectively. It was seen that, as the number of total acedogens decreased, the COD removal efficiencies increased. However, the number of total methanogens increased as the COD removal efficiencies increased. Correlations between the bacterial number and with the removal efficiencies obtained in different operational conditions were investigated. From the results presented in this paper a high correlation between the number of bacteria, COD removals, methane gas percentage, 2,4 DCP removals and VFA was observed. In the second part, methanogen bacteria in the anaerobic granular sludge were identified. Microbial observations and biochemical tests were applied to identify the anaerobic microorganisms from the anaerobic granular sludge. In the reactor treating 2,4 DCP, Methanobacterium bryantii, Methanobacterium formicicum, Methanobrevibacter smithii, Methanococcus voltae, Methanosarcina mazei, Methanosarcina acetivorans, Methanogenium bourgense and

  1. Uso de lagoa aerada facultativa como polimento do reator anaeróbio de manta de lodo UASB no tratamento de dejetos de suínos em escala laboratorial The efficiency of an aerated pond used for treating the effluent of an UASB reactor (upflow anaerobic sludge blanket reactor treating swine manure in a lab-scale system

    Directory of Open Access Journals (Sweden)

    Fernanda Ribeiro do Carmo

    2004-06-01

    Full Text Available As atividades agroindustriais têm se voltado não somente para o aumento da produtividade, mas também para a conservação do meio ambiente. A suinocultura é, sem dúvida, uma das atividades agroindustriais mais poluidoras, principalmente no Estado de Minas Gerais. Sendo assim, objetivou-se desenvolver e operar uma Lagoa Aerada Facultativa (LAF em escala de bancada (laboratorial, e como polimento de um Reator Anaeróbio de Manta de Lodo (UASB, visando a tratar os dejetos de suínos com máxima eficiência e custo mínimo. O experimento foi conduzido no Laboratório de Análise de Água do Departamento de Engenharia (LAADEG da Universidade Federal de Lavras (UFLA, sendo composto por um tanque de acidificação e equalização (TAE, um reator anaeróbio de manta de lodo (UASB e uma lagoa aerada facultativa (LAF para polimento. As análises fisico-químicas realizadas foram: pH, DBO5, DQO T, Sólidos Totais (fixos e voláteis, Temperatura, Nitrogênio, Fósforo, Alcalinidade e Acidez Total. A unidade LAF mostrou uma eficiência média de 83 e 42% de DQO T e Nitrogênio Total, respectivamente. O sistema proporcionou remoção média de 93, 84 e 85% de DQO T, DBO5 e Sólidos Totais Voláteis, respectivamente.Nowadays the agro-industry activities have not only focused its direction to the production increasing, but also, to the environmental preservation. The swine production is amo doubt, an activity, which can be considered, one of the most pollutants, mainly in the Minas Gerais State (BRAZIL. Therefore, this research aimed at developing and operating an Upflow Anaerobic Sludge Blanket Reactor (UASB, followed by an Aerobic Facultative Pound (AFP (Lab-Scale, with the objective of treating the liquid effluent originated from swine with the maximum efficiency and lower costs. The experiment was carried out in the Laboratory of Water Analysis of the Engineering Department of the Federal University of Lavras (UFLA. The system was assembled with an

  2. Evaluation of integrated anaerobic-aerobic biofilm reactor for degradation of azo dye methyl orange.

    Science.gov (United States)

    Murali, V; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian

    2013-09-01

    This study was to investigate the mineralization of wastewater containing methyl orange (MO) in integrated anaerobic-aerobic biofilm reactor with coconut fiber as bio-material. Different aeration periods (3h in phase 1 and 2; 3, 6 and 15 h in phase 3; 24 h in phase 4 and 5) in aerobic chamber were studied with different MO concentration 50, 100, 200, 200 and 300 mg/L as influent from phase 1-5. The color removals estimated from the standard curve of dye versus optical density at its maximum absorption wavelength were 97%, 96%, 97%, 97%, and 96% and COD removals were 75%, 72%, 63%, 81%, and 73% in phase 1-5, respectively. The MO decolorization and COD degradation followed first-order kinetic model and second-order kinetic model, respectively. GC-MS analysis indicated the symmetrical cleavage of azo bond and the reduction in aromatic peak ensured the partial mineralization of MO.

  3. ANAEROBIC-AEROBIC TREATMENT OF TEXTILE WASTEWATER IN A SEQUENCING BATCH REACTOR

    Directory of Open Access Journals (Sweden)

    IBTISSAM KANBOUCHI

    2014-04-01

    Full Text Available In this work, the treatment of synthetic textile wastewater using sequential batch reactor (SBR was studied. This in order to predict the effectiveness of biological treatment on wastewater containing dyes while minimizing the aeration cost. Laboratory tests were performed on synthetic wastewater containing filtered urban wastewater (source of bacteria and dyes solutions. This promotes the biomass development in the mixture, capable of degrading organic matter properly. The results indicate that the increasing of anaerobic phase (16 hours allows removal of 77 % and 80 % of COD and colour, respectively. The sludge age did not affect markedly dyes biodegradability. However, the biodegradability is strongly influenced by the dyes concentration. Indeed, for the lowest dyes contents, improved biodegradability was observed, while it decreases when the dyes concentration increases.

  4. Kinetics of psychrophilic anaerobic sequencing batch reactor treating flushed dairy manure.

    Science.gov (United States)

    Ma, Jingwei; Yu, Liang; Frear, Craig; Zhao, Quanbao; Li, Xiujin; Chen, Shulin

    2013-03-01

    In this study, a new strategy, improving biomass retention with fiber material present within the dairy manure as biofilm carriers, was evaluated for treating flushed dairy manure in a psychrophilic anaerobic sequencing batch reactor (ASBR). A kinetic study was carried out for process control and design by comparing four microbial growth kinetic models, i.e. first order, Grau, Monod and Chen and Hashimoto models. A volumetric methane production rate of 0.24L/L/d of and a specific methane productivity of 0.19L/gVSloaded were achieved at 6days HRT. It was proved that an ASBR using manure fiber as support media not only improved methane production but also reduced the necessary HRT and temperature to achieve a similar treating efficiency compared with current technologies. The kinetic model can be used for design and optimization of the process.

  5. Fermentative hydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor

    Science.gov (United States)

    Wu, Xiao

    2009-12-01

    The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant

  6. Understanding the removal mechanisms of PPCPs and the influence of main technological parameters in anaerobic UASB and aerobic CAS reactors

    Energy Technology Data Exchange (ETDEWEB)

    Alvarino, T., E-mail: teresa.alvarino@usc.es; Suarez, S., E-mail: Sonia.suarez@usc.es; Lema, J.M., E-mail: juan.lema@usc.es; Omil, F., E-mail: francisco.omil@usc.es

    2014-08-15

    Highlights: • Removals of 16 PPCPs under aerobic and anaerobic conditions were quantified. • Operation conditions (HRT, v{sub up}, biomass activity and conformation) influenced removal. • Highest removals associated to aerobic biodegradation. • Sorption was only relevant for lipophilic compounds in the UASB reactor. - Abstract: The removal of 16 Pharmaceutical and Personal Care Products (PPCPs) were studied in a conventional activated sludge (CAS) unit and an upflow anaerobic sludge blanket (UASB) reactor. Special attention was paid to each biomass conformation and activity as well as to operational conditions. Biodegradation was the main PPCP removal mechanism, being higher removals achieved under aerobic conditions, except in the case of sulfamethoxazole and trimetrophim. Under anaerobic conditions, PPCP biodegradation was correlated with the methanogenic rate, while in the aerobic reactor a relationship with nitrification was found. Sorption onto sludge was influenced by biomass conformation, being only significant for musk fragrances in the UASB reactor, in which an increase of the upward velocity and hydraulic retention time improved this removal. Additionally, PPCP sorption increased with time in the UASB reactor, due to the granular biomass structure which suggests the existence of intra-molecular diffusion.

  7. Evaluation of Anaerobic Fluidized Bed Reactor for treating Sugar mill effluent - a Case Study

    Directory of Open Access Journals (Sweden)

    R. Mathiyazhagan

    2014-07-01

    Full Text Available Anaerobic treatment processes are credible options for providing sustainable treatment to biodegradable waste streams. The Anaerobic Fluidized Bed Reactor (AFBR is an evolving process that requires waste specific design methodologies based on kinetics of the specific process. The research was precisely an experimental study on AFBR having23.56 litres of effective volume to evaluate its treatment performance and gas recovery in terms of Chemical Oxygen Demand (COD, Hydraulic Retention Time(HRTand Organic Loading Rate (OLR. The synthetic sugar influent COD was variedfrom 1500 to 4000 mg/lit. The OLR for the operating flow rates were ranged from 1.36 to 28.8 Kg COD/m3 .day for HRT varied from 3.2 to 24 hrs. The maximum COD removal efficiency is 90.06 at an operating OLR of 3.42 Kg COD/m3 .day. The maximum biogas yield was observed at 0.28 m 3 /kg COD removed.

  8. Membrane distillation combined with an anaerobic moving bed biofilm reactor for treating municipal wastewater.

    Science.gov (United States)

    Kim, Hyun-Chul; Shin, Jaewon; Won, Seyeon; Lee, Jung-Yeol; Maeng, Sung Kyu; Song, Kyung Guen

    2015-03-15

    A fermentative strategy with an anaerobic moving bed biofilm reactor (AMBBR) was used for the treatment of domestic wastewater. The feasibility of using a membrane separation technique for post-treatment of anaerobic bio-effluent was evaluated with emphasis on employing a membrane distillation (MD). Three different hydrophobic 0.2 μm membranes made of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polypropylene (PP) were examined in this study. The initial permeate flux of the membranes ranged from 2.5 to 6.3 L m(-2) h(-1) when treating AMBBR effluent at a temperature difference between the feed and permeate streams of 20 °C, with the permeate flux increasing in the order PP distillation, while a flux decline in MD with either the PVDF or PP membrane was not found under the identical distillation conditions. During long-term distillation with the PVDF membrane, total phosphorus was completely rejected and >98% rejection of dissolved organic carbon was also achieved. The characterization of wastewater effluent organic matter (EfOM) using an innovative suite of analytical tools verified that almost all of the EfOM was rejected via the PVDF MD treatment.

  9. Simultaneous degradation of cyanide and phenol in upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Kumar, M Suresh; Mishra, Ram Sushil; Jadhav, Shilpa V; Vaidya, A N; Chakrabarti, T

    2011-07-01

    Coal coking, precious metals mining and nitrile polymer industries generate over several billion liters of cyanide-containing waste annually. Economic and environmental considerations make biological technologies attractive for treatment of wastes containing high organic content, in which the microbial cultures can remove concentrations of organics and cyanide simultaneously. For cyanide and phenol bearing waste treatment, an upflow anaerobic sludge blanket reactor has been developed, which successfully removed free cyanide 98% (with feed concentration of 20 mg 1(-1)) in presence of phenol. The effect of cyanide on phenol degradation was studied with varying concentrations of phenol as well as cyanide under anaerobic conditions. This study revealed that the methanogenic degradation of phenol can occur in the presence of cyanide concentration 30-38 mg 1(-1). Higher cyanide concentration inhibited the phenol degradation rate. The inhibition constant Ki was found to be 38 mg 1(-1) with phenol removal rate of 9.09 mg 1(-1.) x h.

  10. Monitoring anaerobic sequential batch reactors via fractal analysis of pH time series.

    Science.gov (United States)

    Méndez-Acosta, H O; Hernandez-Martinez, E; Jáuregui-Jáuregui, J A; Alvarez-Ramirez, J; Puebla, H

    2013-08-01

    Efficient monitoring and control schemes are mandatory in the current operation of biological wastewater treatment plants because they must accomplish more demanding environmental policies. This fact is of particular interest in anaerobic digestion processes where the availability of accurate, inexpensive, and suitable sensors for the on-line monitoring of key process variables remains an open problem nowadays. In particular, this problem is more challenging when dealing with batch processes where the monitoring strategy has to be performed in finite time, which limits the application of current advanced monitoring schemes as those based in the proposal of nonlinear observers (i.e., software sensors). In this article, a fractal time series analysis of pH fluctuations in an anaerobic sequential batch reactor (AnSBR) used for the treatment of tequila vinasses is presented. Results indicated that conventional on-line pH measurements can be correlated with off-line determined key process variables, such as COD, VFA and biogas production via some fractality indexes.

  11. Methane Emission from Digestion of Palm Oil Mill Effluent (POME in a Thermophilic Anaerobic Reactor

    Directory of Open Access Journals (Sweden)

    I Irvan

    2012-04-01

    Full Text Available As the issue of global warming draws increasing concern, many studies to reduce CO2 and CH4 gases (greenhouse gases, GHG have been implemented in several countries, including in Indonesia. Considering that Indonesia has a huge numbers of palm oil mills, no doubt if their waste water treatment as one of the major sources in GHG.  This paper presents the results from a research project between Metawater Co., Ltd.-Japan and University of Sumatera Utara-Indonesia. The objective of the research is to study the methane emission of thermophilic fermentation in the treatment of palm oil mill effluent (POME on a laboratory scale. Anaerobic digestion was performed in two-litre water jacketed biodigester type continuous stirred tank reactor (CSTR and operated at a thermophilic temperature (55 oC. As raw material, a real liquid waste (POME from palm oil mill was used. Fresh POME was obtained from seeding pond of PTPN II waste water treatment facility which has concentration of 39.7 g of VS/L and COD value of 59,000 mg/L. To gain precise results, complete recording and reliable equipment of reactor was employed. As the experimental results, for hydraulic retention time (HRT 8 days, VS decomposition rate of 63.5% and gas generation of 6.05-9.82 L/day were obtained, while for HRT 6 and 4 days, VS decomposition rate of 61.2, 53.3% and gas generation of  6.93-8.94  and  13.95-16.14 L/day were obtained respectively. Keywords—methane (CH4, palm oil mill effluent (POME, anaerobic digestion, thermophilic, green house gases (GHG

  12. Evaluation of A Novel Split-Feeding Anaerobic/Oxic Baffled Reactor (A/OBR) For Foodwaste Anaerobic Digestate: Performance, Modeling and Bacterial Community

    Science.gov (United States)

    Wang, Shaojie; Peng, Liyu; Jiang, Yixin; Gikas, Petros; Zhu, Baoning; Su, Haijia

    2016-10-01

    To enhance the treatment efficiency from an anaerobic digester, a novel six-compartment anaerobic/oxic baffled reactor (A/OBR) was employed. Two kinds of split-feeding A/OBRs R2 and R3, with influent fed in the 1st, 3rd and 5th compartment of the reactor simultaneously at the respective ratios of 6:3:1 and 6:2:2, were compared with the regular-feeding reactor R1 when all influent was fed in the 1st compartment (control). Three aspects, the COD removal, the hydraulic characteristics and the bacterial community, were systematically investigated, compared and evaluated. The results indicated that R2 and R3 had similar tolerance to loading shock, but the R2 had the highest COD removal of 91.6% with a final effluent of 345 mg/L. The mixing patterns in both split-feeding reactors were intermediate between plug-flow and completely-mixed, with dead spaces between 8.17% and 8.35% compared with a 31.9% dead space in R1. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed that the split-feeding strategy provided a higher bacterial diversity and more stable bacterial community than that in the regular-feeding strategy. Further analysis indicated that Firmicutes, Bacteroidetes, and Proteobacteria were the dominant bacteria, among which Firmicutes and Bacteroidetes might be responsible for organic matter degradation and Proteobacteria for nitrification and denitrification.

  13. Anaerobic digestion of kitchen wastes in a single-phased anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; HE Zheng-guang; ZHANG Li-li; XU Jian-bo; SHI Hong-zhuan; CAI Wei-min

    2005-01-01

    The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2. The ASBR was operated at four chemical oxygen demand(COD) loading rates, 2.8,respectively. The operation of the reactor with gas-phased absorb of CO2 was stable in spite of the low pH (2.6-3.9) and high concentration of TS(142 g/L) of input mixture. The output volatile fatty acid(VFA) concentration was between 2.7-4.7 g/L and had no inhibition on the methanogenic microorganism. The reactor without gas-phased absorb of CO2 became acidified when the total COD alkaline will be required to keep pH in the appropriate range for the methanogenic microorganism based on theoretical calculation. Gasphased absorb of CO2 effectively reduced the alkaline consumption, hence avoided excessive cation into the reactor.

  14. Study of thermophilic anaerobic cleaning systems; Studier av termofila anaeroba reningssystem

    Energy Technology Data Exchange (ETDEWEB)

    Boman, B.; Davisson, G.

    1994-11-01

    The aim of this study was to indicate how mesophile and thermophilic anaerobic systems differ in their capacity to degrade persistent organic compounds. The experiments were carried out in semi-batch lab.scale reactors working at 35, 55 and 70 degrees C and were evaluated by recording pH, COD, TSS, redox potential, fatty acids, gas production, methane concentration and the concentration of specific organic compounds. Totally, seven different reactors and four different specific organic compounds were used in this study. The microbial activity within the semi-batch reactors showed a pronounced tendency to oscillate in an irregular and unpredictable way. This behaviour stressed the difficulties in running the decided experiments. These experiences are unfortunately confirmed by many other investigators within the present field. The results do not indicate differences between mesophile and thermophilic anaerobic reactors in terms of `not degradable-degradable` but only as differences in degree of degradation rates. 6-chlorovanillin and 3,5-dinitrobenzoic acid showed increasing degradation rate in the thermophilic range while no differences could be detected for 4,5-dichloroguaiacol. In the case of {beta}-sitosterol the mesophile reference reactor crash. 14 refs, 6 figs, 3 tabs

  15. Start-up of a thermophilic upflow anaerobic sludge bed (UASB) reactor with mesophilic granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lier, J.B. van; Grolle, K.C.F.; Lettinga, G. (Wageningen Agricultural Univ. (Netherlands). Dept. of Environmental Technology); Stams, A.J.M. (Wageningen Agricultural Univ. (Netherlands). Dept. of Microbiology); Conway de Macario, E. (New York State Dept. of Health, Albany, NY (United States). Wadsworth Center for Laboratories and Research State Univ. of New York, Albany, NY (United States). School of Public Health)

    1992-04-01

    Fast start-up of thermophilic upflow anaerobic sludge bed (UASB) reactors was achieved at process temperatures of 46, 55 and 64deg C, using mesophilic granular sludge as inoculum and fatty acid mixtures as feed. The start-up was brought about by increasing the temperature of mesophilic UASB reactors in a single step, which initially led to a sharp drop in the methane-production rate. Thereafter, stable thermophilic methanogenesis was achieved within a period of 1 or 2 weeks depending on the temperature of operation. Mesophilic granules functioned initially as effective carrier material for thermophilic organisms. However, long-term operation led to disintegration of the granules, resulting in wash-out of thermophilic biomass. The temperature optima for acetotrophic methanogenic activity of the sludges cultivated at 46, 55 and 64deg C, were similar, but differed significantly from the temperature optimum of the mesophilic inoculum. All the sludges examined were dominated by Methanothrix-like rods. These could be distinguished by antigenic fingerprinting into two subpopulations, one predominant at 36deg C and the other predominant at 46deg C and above. (orig.).

  16. Effects of the antimicrobial tylosin on the microbial community structure of an anaerobic sequencing batch reactor.

    Science.gov (United States)

    Shimada, Toshio; Li, Xu; Zilles, Julie L; Morgenroth, Eberhard; Raskin, Lutgarde

    2011-02-01

    The effects of the antimicrobial tylosin on a methanogenic microbial community were studied in a glucose-fed laboratory-scale anaerobic sequencing batch reactor (ASBR) exposed to stepwise increases of tylosin (0, 1.67, and 167 mg/L). The microbial community structure was determined using quantitative fluorescence in situ hybridization (FISH) and phylogenetic analyses of bacterial 16S ribosomal RNA (rRNA) gene clone libraries of biomass samples. During the periods without tylosin addition and with an influent tylosin concentration of 1.67 mg/L, 16S rRNA gene sequences related to Syntrophobacter were detected and the relative abundance of Methanosaeta species was high. During the highest tylosin dose of 167 mg/L, 16S rRNA gene sequences related to Syntrophobacter species were not detected and the relative abundance of Methanosaeta decreased considerably. Throughout the experimental period, Propionibacteriaceae and high GC Gram-positive bacteria were present, based on 16S rRNA gene sequences and FISH analyses, respectively. The accumulation of propionate and subsequent reactor failure after long-term exposure to tylosin are attributed to the direct inhibition of propionate-oxidizing syntrophic bacteria closely related to Syntrophobacter and the indirect inhibition of Methanosaeta by high propionate concentrations and low pH.

  17. Microbial community structure and performance of an anaerobic reactor digesting cassava pulp and pig manure.

    Science.gov (United States)

    Panichnumsin, P; Ahring, B; Nopharatana, A; Chaiprasert, P

    2012-01-01

    Microbial community dynamics in response to changes in substrate types (i.e. pig manure (PM), cassava pulp (CP) and mixtures of PM and CP) were investigated in an anaerobic continuously stirred tank reactor (CSTR). Molecular identification of bacterial and archaeal domains were performed, using a 16S rDNA clone library with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) screening and phylogenetic analysis. Analysis of bacterial clone libraries revealed that the differences in the community structure corresponded to the substrate types. However, the Bacteroidetes were the most abundant group in all substrates, followed by the Clostridia. With pure PM, the dominant bacterial groups were Bacteroidales, Clostridia and Paludibacter. With a co-substrate, at CP to PM (CP:PM) ratio of 50:50, the sequences analysis revealed the greatest diversity of bacterial communities at class level, and the sequences affiliated with Cytophaga sp. became an exclusive predominant. With CP alone, Bacteroides sp. was the dominant species and this reactor had the lowest diversity of bacteria. Archaea observed in the CSTR fed with all substrate types were Methanosaeta sp., Methanosaeta concilii and Methanospirillum hungatei. Among the Archaea, Methanosaeta sp. was the exclusive predominant. The relative distribution of Archaea also changed regarding to the substrate types.

  18. Biohydrogen production from cassava wastewater in an anaerobic fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    N. C. S. Amorim

    2014-09-01

    Full Text Available The effect of hydraulic retention time (HRT and organic loading rate (OLR on biological hydrogen production was assessed using an anaerobic fluidized bed reactor fed with cassava wastewater. The HRT of this reactor ranged from 8 to 1 h (28 to 161 kg COD/m³-d. The inoculum was obtained from a facultative pond sludge derived from swine wastewater treatment. The effluent pH was approximately 5.00, while the influent chemical oxygen demand (COD measured 4000 mg COD/L. The hydrogen yield production increased from 0.13 to 1.91 mol H2/mol glucose as the HRT decreased from 8 to 2 h. The hydrogen production rate significantly increased from 0.20 to 2.04 L/h/L when the HRT decreased from 8 to 1 h. The main soluble metabolites were ethanol (1.87-100%, acetic acid (0.00-84.80%, butyric acid (0.00-66.78% and propionic acid (0.00-50.14%. Overall, we conclude that the best hydrogen yield production was obtained at an HRT of 2 h.

  19. A two-stage anaerobic system for biodegrading wastewater containing terephthalic acid and high strength easily degradable pollutants

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The high strength easily biodegradable pollutants(represented by CODE) are strong inhibitors of terephthalic acid(TA) anaerobic biodegradation. At the same time, TA can inhibiteasily biodegradable pollutants removal under anaerobic conditionsto a limited extent. This mutual inhibition could happen and causea low removal efficiency of both TA and CODE, when the effluentfrom TA workshops containing TA and easily biodegradable pollutantsare treated by a single anaerobic reactor system. Based upon thetreatment kinetics analysis of both TA degradation and CODEremoval, a two-stage up-flow anaerobic sludge blanket and up-flowfixed film reactor(UASB-UAFF) system for dealing with this kind ofwastewater was developed and run successfully at laboratory scale.An UASB reactor with the methanogenic consortium as the first stageremoves the easily biodegradable pollutants(CODE). An UAFF reactor as the second stage is mainly in charge of TA degradation. At aHRT 18.5h, the CODE and TA removal rate of the system reached 89.2% and 71.6%, respectively.

  20. Fast breeder reactor protection system

    Science.gov (United States)

    van Erp, J.B.

    1973-10-01

    Reactor protection is provided for a liquid-metal-fast breeder reactor core by measuring the coolant outflow temperature from each of the subassemblies of the core. The outputs of the temperature sensors from a subassembly region of the core containing a plurality of subassemblies are combined in a logic circuit which develops a scram alarm if a predetermined number of the sensors indicate an over temperature condition. The coolant outflow from a single subassembly can be mixed with the coolant outflow from adjacent subassemblies prior to the temperature sensing to increase the sensitivity of the protection system to a single subassembly failure. Coherence between the sensors can be required to discriminate against noise signals. (Official Gazette)

  1. NMR and MALDI-TOF MS based characterization of exopolysaccharides in anaerobic microbial aggregates from full-scale reactors

    KAUST Repository

    Gonzalez-Gil, Graciela

    2015-09-22

    Anaerobic granular sludge is composed of multispecies microbial aggregates embedded in a matrix of extracellular polymeric substances (EPS). Here we characterized the chemical fingerprint of the polysaccharide fraction of EPS in anaerobic granules obtained from full-scale reactors treating different types of wastewater. Nuclear magnetic resonance (NMR) signals of the polysaccharide region from the granules were very complex, likely as a result of the diverse microbial population in the granules. Using nonmetric multidimensional scaling (NMDS), the 1H NMR signals of reference polysaccharides (gellan, xanthan, alginate) and those of the anaerobic granules revealed that there were similarities between the polysaccharides extracted from granules and the reference polysaccharide alginate. Further analysis of the exopolysaccharides from anaerobic granules, and reference polysaccharides using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that exopolysaccharides from two of the anaerobic granular sludges studied exhibited spectra similar to that of alginate. The presence of sequences related to the synthesis of alginate was confirmed in the metagenomes of the granules. Collectively these results suggest that alginate-like exopolysaccharides are constituents of the EPS matrix in anaerobic granular sludge treating different industrial wastewater. This finding expands the engineered environments where alginate has been found as EPS constituent of microbial aggregates.

  2. Digestion of frozen/thawed food waste in the hybrid anaerobic solid-liquid system.

    Science.gov (United States)

    Stabnikova, O; Liu, X Y; Wang, J Y

    2008-01-01

    The hybrid anaerobic solid-liquid (HASL) system, which is a modified two-phase anaerobic digester, is to be used in an industrial scale operation to minimize disposal of food waste at incineration plants in Singapore. The aim of the present research was to evaluate freezing/thawing of food waste as a pre-treatment for its anaerobic digestion in the HASL system. The hydrolytic and fermentation processes in the acidogenic reactor were enhanced when food waste was frozen for 24h at -20 degrees C and then thawed for 12h at 25 degrees C (experiment) in comparison with fresh food waste (control). The highest dissolved COD concentrations in the leachate from the acidogenic reactors were 16.9 g/l on day 3 in the control and 18.9 g/l on day 1 in the experiment. The highest VFA concentrations in the leachate from the acidogenic reactors were 11.7 g/l on day 3 in the control and 17.0 g/l on day 1 in the experiment. The same volume of methane was produced during 12 days in the control and 7 days in the experiment. It gave the opportunity to diminish operational time of batch process by 42%. The effect of freezing/thawing of food waste as pre-treatment for its anaerobic digestion in the HASL system was comparable with that of thermal pre-treatment of food waste at 150 degrees C for 1h. However, estimation of energy required either to heat the suspended food waste to 150 degrees C or to freeze the same quantity of food waste to -20 degrees C showed that freezing pre-treatment consumes about 3 times less energy than thermal pre-treatment.

  3. Model-Based Feasibility Assessment of Membrane Biofilm Reactor to Achieve Simultaneous Ammonium, Dissolved Methane, and Sulfide Removal from Anaerobic Digestion Liquor

    Science.gov (United States)

    Chen, Xueming; Liu, Yiwen; Peng, Lai; Yuan, Zhiguo; Ni, Bing-Jie

    2016-04-01

    In this study, the membrane biofilm reactor (MBfR) is proposed to achieve simultaneous removal of ammonium, dissolved methane, and sulfide from main-stream and side-stream anaerobic digestion liquors. To avoid dissolved methane stripping, oxygen is introduced through gas-permeable membranes, which also from the substratum for the growth of a biofilm likely comprising ammonium oxidizing bacteria (AOB), anaerobic ammonium oxidation (Anammox) bacteria, denitrifying anaerobic methane oxidation (DAMO) microorganisms, aerobic methane oxidizing bacteria (MOB), and sulfur oxidizing bacteria (SOB). A mathematical model is developed and applied to assess the feasibility of such a system and the associated microbial community structure under different operational conditions. The simulation studies demonstrate the feasibility of achieving high-level (>97.0%), simultaneous removal of ammonium, dissolved methane, and sulfide in the MBfRs from both main-stream and side-stream anaerobic digestion liquors through adjusting the influent surface loading (or hydraulic retention time (HRT)) and the oxygen surface loading. The optimal HRT was found to be inversely proportional to the corresponding oxygen surface loading. Under the optimal operational conditions, AOB, DAMO bacteria, MOB, and SOB dominate the biofilm of the main-stream MBfR, while AOB, Anammox bacteria, DAMO bacteria, and SOB coexist in the side-stream MBfR to remove ammonium, dissolved methane, and sulfide simultaneously.

  4. A reactor system combining reductive dechloirnation with cometabolic oxidation for complete degradation of tetrachloroentylene

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A laboratory sequential anaerobic-aerobic bioreactor system,which consisted of an anaerobic fixed film reactor and twoaerobic chemostats, was set up to degrade tetrachloroethylene (PCE)without accumulating highly toxic degradation intermediates. A soil(ca. 150 mg/liter) of PCE stoichiometrically intocis-1,2-dichloroethylene (cis-DCE), was attached to ceramic mediain the anaerobic fixed film reactor. A phenol degrading strain,Alcaligenes sp. R5, which can efficiently degrade cis-DCE byco-metabolic oxidation, was used as inoculum for the aerobicchemostats consisted of a transformation reactor and a growthreactor. The anaerobic fixed film bioreactor showed more than 99 %of PCE transformation into cis-DCE in the range of influent PCE48h. On the other hand, efficient degradation of the resultantcis-DCE by strain R5 in the following aerobic system could not beachieved due to oxygen limitation. However, 54% of the maximum(H2O2) was supplemented to the transformation reactor as anadditional oxygen source. Further studies are needed to achievemore efficient co-metabolic degradation of cis-DCE in the aerobic reactor.

  5. Anaerobic digestion of manure and mixture of manure with lipids: biogas reactor performance and microbial community analysis

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Dabrowski, Slawomir; Ahring, Birgitte Kiær

    2003-01-01

    Anaerobic digestion of cattle manure and a mixture of cattle manure with glycerol trioleate (GTO) was studied in lab-scale, continuously stirred tank reactors (CSTR) operated at 37degreesC. The reactor. codigesting manure and lipids exhibited a significantly higher specific methane yield...... and a higher removal of VS than the reactor treating manure. Microbial population analysis done by cultivation - most probable number (MPN) test and specific methanogenic activity (SMA) measurement, revealed higher MPN and increased SMA of methanogenic populations of biomass from the reactor codigesting manure...... and lipids. Spatial microbial distribution and activity was studied in digested materials fractionated into size of particles > 200 mum, 50-200 mum and 0.45-50 mum. With manure, the main pool of methanogenic activity from propionate, butyrate and hydrogen was associated with the particles > 200 mum, while...

  6. Anaerobic co-digestion of biodiesel waste glycerin with municipal wastewater sludge: microbial community structure dynamics and reactor performance.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2015-04-01

    Two 10 L completely mixed reactors operating at 37°C and 20 days SRT were used to evaluate the relationships between reactor performance and microbial community dynamics during anaerobic co-digestion of biodiesel waste glycerin (BWG) with municipal wastewater sludge (MWS). The addition of up to 1.35% (v/v) BWG to reactor feeds yielded increased VS and COD removal together with enhanced the biogas production and methane yield. This represented 50% of the MWS feed COD. Pyrosequencing analysis showed Methanosaeta (acetoclastic) and Methanomicrobium (hydrogenotrophic) to be the methanogenic genera present in greatest diversity during stable reactor operation. Methanosaeta sequences predominated at the lowest BWG loading while those of Methanomicrobium were present in greatest abundance at the higher BWG loadings. Genus Candidatus cloacamonas was present in the greatest number of bacterial sequences at all loadings. Alkalinity, pH, biogas production and methane yield declined and VFA concentrations (especially propionate) increased during the highest BWG loading.

  7. Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors.

    Science.gov (United States)

    Robles, A; Latrille, E; Ribes, J; Bernet, N; Steyer, J P

    2016-01-01

    The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitoring the start-up period of anaerobic fixed-bed reactors due to its reliability, robustness, easy operation, low cost, and minimum maintenance compared with the currently used sensors.

  8. Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia...... recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7g-N/L during 30days, resulting in an average recovery rate of 80g-N/m2/d. Meanwhile, a maximum power density of 0.71±0.5W/m2 was generated at 2.85A/m2. Both current driven NH4+ migration...

  9. Anaerobic treatment of wastewater with high suspended solids from a bulk drug industry using fixed film reactor (AFFR).

    Science.gov (United States)

    Gangagni Rao, A; Venkata Naidu, G; Krishna Prasad, K; Chandrasekhar Rao, N; Venkata Mohan, S; Jetty, Annapurna; Sarma, P N

    2005-01-01

    Studies were carried out on the treatment of wastewater from a bulk drug industry using an anaerobic fixed film reactor (AFFR) designed and fabricated in the laboratory. The chemical oxygen demand (COD) and total dissolved solids (TDS) of the wastewater were found to be very high with low biochemical oxygen demand (BOD) to COD ratio and high total suspended solid (TSS) concentration. Acclimatization of seed consortia and startup of the reactor was carried out by directly using the wastewater, which resulted in reducing the period of startup to 30 days. The reactor was studied at different organic loading rates (OLR) and it was found that the optimum OLR was 10 kg COD/m(3)/day. The wastewater under investigation, which had a considerable quantity of SS, was treated anaerobically without any pretreatment. COD and BOD of the reactor outlet wastewater were monitored and at steady state and optimum OLR 60-70% of COD and 80-90% of BOD were removed. The reactor was subjected to organic shock loads at two different OLR and the reaction could withstand the shocks and performance could be restored to normalcy at that OLR. The results obtained indicated that AFFR could be used efficiently for the treatment of wastewater from a bulk drug industry having high COD, TDS and TSS.

  10. Influence of support material on the immobilization of biomass for the degradation of linear alkylbenzene sulfonate in anaerobic reactors.

    Science.gov (United States)

    Lima de Oliveira, Lorena; Silveira Duarte, Iolanda Cristina; Sakamoto, Isabel Kimiko; Amâncio Varesche, Maria Bernadete

    2009-02-01

    Two horizontal-flow anaerobic immobilized biomass reactors (HAIB) were used to study the degradation of the LAS surfactant: one filled with charcoal (HAIB1) and the other with a mixed bed of expanded clay and polyurethane foam (HAIB2). The reactors were fed with synthetic substrate supplemented with 14 mg l(-1)of LAS, kept at 30+/-2 degrees C and operated with a hydraulic retention time (HRT) of 12h. The surfactant was quantified by HPLC. Spatial variation analyses were done to quantify organic matter and LAS consumption along the reactor length. The presence of the surfactant in the load did not affect the removal of organic matter (COD), which was close to 90% in both reactors for an influent COD of 550 mg l(-1). The results of a mass balance indicated that 28% of all LAS added to HAIB1 was removed by degradation. HAIB2 presented 27% degradation. Molecular biology techniques revealed microorganisms belonging the uncultured Holophaga sp., uncultured delta Proteobacterium, uncultured Verrucomicrobium sp., Bacteroides sp. and uncultured gamma Proteobacterium sp. The reactor with biomass immobilized on charcoal presented lower adsorption and a higher kinetic degradation coefficient. So, it was the most suitable support for LAS anaerobic treatment.

  11. Ethanol Production from Wet-Exploded Wheat Straw Hydrolysate by Thermophilic Anaerobic Bacterium Thermoanaerobacter BG1L1 in a Continuous Immobilized Reactor

    Science.gov (United States)

    Georgieva, Tania I.; Mikkelsen, Marie J.; Ahring, Birgitte K.

    Thermophilic ethanol fermentation of wet-exploded wheat straw hydrolysate was investigated in a continuous immobilized reactor system. The experiments were carried out in a lab-scale fluidized bed reactor (FBR) at 70°C. Undetoxified wheat straw hydrolysate was used (3-12% dry matter), corresponding to sugar mixtures of glucose and xylose ranging from 12 to 41 g/1. The organism, thermophilic anaerobic bacterium Thermoanaerobacter BG1L1, exhibited significant resistance to high levels of acetic acid (up to 10 g/1) and other metabolic inhibitors present in the hydrolysate. Although the hydrolysate was not detoxified, ethanol yield in a range of 0.39-0.42 g/g was obtained. Overall, sugar efficiency to ethanol was 68-76%. The reactor was operated continuously for approximately 143 days, and no contamination was seen without the use of any agent for preventing bacterial infections. The tested microorganism has considerable potential to be a novel candidate for lignocellulose bioconversion into ethanol. The work reported here also demonstrates that the use of FBR configuration might be a viable approach for thermophilic anaerobic ethanol fermentation.

  12. Proteolytic bacterial dominance in a full-scale municipal solid waste anaerobic reactor assessed by 454 pyrosequencing technology.

    Science.gov (United States)

    Cardinali-Rezende, Juliana; Rojas-Ojeda, Patricia; Nascimento, Andréa M A; Sanz, José L

    2016-03-01

    Biomethanization entails a good means to reduce the organic fraction (OF) derived from municipal solid wastes (MSW). The bacterial diversity of a full scale MSW anaerobic reactor located in Madrid (Spain) was investigated using high-throughput 454 pyrosequencing. Even though the proteolytic bacteria prevailed throughout all of the process, community shifts were observed from the start-up to the steady-state conditions, with an increasing biodiversity displayed over time. The Bacteroidetes and the Firmicutes were the majority phyla: 55.1 and 40.2% (start-up) and 18.7 and 78.7 (steady-state) of the total reads. The system's lack of evenness remains noteworthy as the sequences affiliated to the proteolytic non-saccharolytic Proteiniphylum, Gallicola and Fastidiosipila genera, together with the saccharolytic Saccharofermentans, were predominant on the system and this predominance appears to correlate with the presence of a high ammonium concentration. The 454 pyrosequencing revealed a great diversity of rare organisms which seemingly do not sustain any metabolic roles in the course of the OF-MSW degradation. However, this scarce and unique microbiota can confer great resilience to the system as a buffer against nutritional and environmental changing conditions, thus opening the door to increase the current knowledge about the bacterial community dynamics taking place during MSW treatment processes.

  13. Spatial Abundance and Distribution of Potential Microbes and Functional Genes Associated with Anaerobic Mineralization of Pentachlorophenol in a Cylindrical Reactor

    Science.gov (United States)

    Li, Zhi-Ling; Nan, Jun; Huang, Cong; Liang, Bin; Liu, Wen-Zong; Cheng, Hao-Yi; Zhang, Chunfang; Zhang, Dongdong; Kong, Deyong; Kanamaru, Kyoko; Kobayashi, Tetsuo; Wang, Ai-Jie; Katayama, Arata

    2016-01-01

    Functional interplays of microbial activity, genetic diversity and contaminant transformation are poorly understood in reactors for mineralizing halogenated aromatics anaerobically. Here, we investigated abundance and distribution of potential microbes and functional genes associated with pentachlorophenol (PCP) anaerobic mineralization in a continuous-flow cylindrical reactor (15 cm in length). PCP dechlorination and the metabolite (phenol) were observed at segments 0–8 cm from inlet, where key microbes, including potential reductive dechlorinators (Dehalobacter, Sulfurospirillum, Desulfitobacterium and Desulfovibrio spp.) and phenol degraders (Cryptanaerobacter and Syntrophus spp.), as well as putative functional genes, including putative chlorophenol reductive dehalogenase (cprA) and benzoyl-CoA reductase (bamB), were highly enriched simultaneously. Five types of putative cprAs, three types of putative bamBs and seven types of putative nitrogenase reductase (nifHs) were determined, with their copy numbers decreased gradually from inlet to outlet. Distribution of chemicals, bacteria and putative genes confirmed PCP dechlorination and phenol degradation accomplished in segments 0–5 cm and 0–8 cm, respectively, contributing to a high PCP mineralization rate of 3.86 μM d‑1. Through long-term incubation, dechlorination, phenol degradation and nitrogen fixation bacteria coexisted and functioned simultaneously near inlet (0–8 cm), verified the feasibility of anaerobic mineralization of halogenated aromatics in the compact reactor containing multiple functional microbes.

  14. Performance comparison of a continuous-flow stirred-tank reactor and an anaerobic sequencing batch reactor for fermentative hydrogen production depending on substrate concentration.

    Science.gov (United States)

    Kim, S-H; Han, S-K; Shin, H-S

    2005-01-01

    This study was conducted to compare the performance of a continuous-flow stirred-tank reactor (CSTR) and an anaerobic sequencing batch reactor (ASBR) for fermentative hydrogen production at various substrate concentrations. Heat-treated anaerobic sludge was utilized as an inoculum, and hydraulic retention time (HRT) for each reactor was maintained at 12 h. At the influent sucrose concentration of 5 g COD/L, start-up was not successful in both reactors. The CSTR, which was started-up at 10 g COD/L, showed stable hydrogen production at the influent sucrose concentrations of 10-60 g COD/L during 203 days. Hydrogen production was dependent on substrate concentration, resulting in the highest performance at 30 g COD/L. At the lower substrate concentration, the hydrogen yield (based on hexose consumed) decreased with biomass reduction and changes in fermentation products. At the higher substrate concentration, substrate inhibition on biomass growth caused the decrease of carbohydrate degradation and hydrogen yield (based on hexose added). The ASBR showed higher biomass concentration and carbohydrate degradation efficiency than the CSTR, but hydrogen production in the ASBR was less effective than that in the CSTR at all the substrate concentrations.

  15. Assessment of active methanogenic archaea in a methanol-fed upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Cerrillo, Míriam; Morey, Lluís; Viñas, Marc; Bonmatí, August

    2016-12-01

    Methanogenic archaea enrichment of a granular sludge was undertaken in an upflow anaerobic sludge blanket (UASB) reactor fed with methanol in order to enrich methylotrophic and hydrogenotrophic methanogenic populations. A microbial community assessment, in terms of microbial composition and activity-throughout the different stages of the feeding process with methanol and acetate-was performed using specific methanogenic activity (SMA) assays, quantitative real-time polymerase chain reaction (qPCR), and high-throughput sequencing of 16S ribosomal RNA (rRNA) genes from DNA and complementary DNA (cDNA). Distinct methanogenic enrichment was revealed by qPCR of mcrA gene in the methanol-fed community, being two orders of magnitude higher with respect to the initial inoculum, achieving a final mcrA/16S rRNA ratio of 0.25. High-throughput sequencing analysis revealed that the resulting methanogenic population was mainly composed by methylotrophic archaea (Methanomethylovorans and Methanolobus genus), being also highly active according to the RNA-based assessment. SMA confirmed that the methylotrophic pathway, with a direct conversion of methanol to CH4, was the main step of methanol degradation in the UASB. The biomass from the UASB, enriched in methanogenic archaea, may bear great potential as additional inoculum for bioreactors to carry out biogas production and other related processes.

  16. Microalgal growth in municipal wastewater treated in an anaerobic moving bed biofilm reactor.

    Science.gov (United States)

    Hultberg, Malin; Olsson, Lars-Erik; Birgersson, Göran; Gustafsson, Susanne; Sievertsson, Bertil

    2016-05-01

    Nutrient removal from the effluent of an anaerobic moving bed biofilm reactor (AnMBBR) treated with microalgae was evaluated. Algal treatment was highly efficient in removal of nutrients and discharge limits were met after 3days. Extending the cultivation time from 3 to 5days resulted in a large increase in biomass, from 233.3±49.3 to 530.0±72.1mgL(-1), despite nutrients in the water being exhausted after 3days (ammonium 0.04mgL(-1), orthophosphate <0.05mgL(-1)). Biomass productivity, lipid content and quality did not differ in microalgal biomass produced in wastewater sampled before the AnMBBR. The longer cultivation time resulted in a slight increase in total lipid concentration and a significant decrease in linolenic acid concentration in all treatments. Differences were observed in chemical oxygen demand, which decreased after algal treatment in wastewater sampled before the AnMBBR whereas it increased after algal treatment in the effluent from the AnMBBR.

  17. Removal of Organic Load in Communal Wastewater by using the Six Stage Anaerobic Baffle Reactor (ABR

    Directory of Open Access Journals (Sweden)

    Trilita Minarni Nur

    2016-01-01

    Full Text Available The reduction of water quality in the urban drainage is a crucial problem to overcome because it can affect the health of community. This fact encouraged the researcher to conduct the research in efforts to increase the water quality in the drainage. One of the solutions to increase the water quality in the drainage is that the domestic wastewater must be treated at first before it is flown through the drainage. Furthermore, the wastewater treatment was conducted by employing the communal wastewater processor. The research was aimed at knowing the capability of Anaerobic Baffle Reactor with the six-stage design in communal wastewater processor in efforts to decrease the organic load. This research was conducted in a laboratory scale. Meanwhile, the sort of waste used was taken from the domestic wastewater of settlement by varying its discharge and waste concentration flowing into the waste processor. Finally, the research result showed that the reduction of organic load of COD was reaching up to 92%, N was 85% and Phosphate was 50%.

  18. Anaerobic baffled reactor coupled with chemical precipitation for treatment and toxicity reduction of industrial wastewater.

    Science.gov (United States)

    Laohaprapanona, Sawanya; Marquesa, Marcia; Hogland, William

    2014-01-01

    This study describes the reduction of soluble chemical oxygen demand (CODs) and the removal of dissolved organic carbon (DOC), formaldehyde (FA) and nitrogen from highly polluted wastewater generated during cleaning procedures in wood floor manufacturing using a laboratory-scale biological anaerobic baffled reactor followed by chemical precipitation using MgCI2 .6H20 + Na2HPO4. By increasing the hydraulic retention time from 2.5 to 3.7 and 5 days, the reduction rates of FA, DOC and CODs of nearly 100%, 90% and 83%, respectively, were achieved. When the Mg:N:P molar ratio in the chemical treatment was changed from 1:1:1 to 1.3:1:1.3 at pH 8, the NH4+ removal rate increased from 80% to 98%. Biologically and chemically treated wastewater had no toxic effects on Vibrio fischeri and Artemia salina whereas chemically treated wastewater inhibited germination of Lactuca sativa owing to a high salt content. Regardless of the high conductivity of the treated wastewater, combined biological and chemical treatment was found to be effective for the removal of the organic load and nitrogen, and to be simple to operate and to maintain. A combined process such as that investigated could be useful for on-site treatment of low volumes of highly polluted wastewater generated by the wood floor and wood furniture industries, for which there is no suitable on-site treatment option available today.

  19. Two stage anaerobic baffled reactors for bio-hydrogen production from municipal food waste.

    Science.gov (United States)

    Tawfik, A; Salem, A; El-Qelish, M

    2011-09-01

    A two-step anaerobic baffled reactor (ABR-1 and ABR-2) for H2 production from municipal food waste (MFW) was investigated at a temperature of 26 °C. In ABR-1, the average yield of H2 at an HRT of 26 h and OLR of 58 kg COD/m3 d was 250 ml H2/g VS removed. As unexpected; the H2 production in the ABR-2 was further increased up to 370 ml H2/gVS removed at a HRT of 26 h and OLR of 35 kg COD/m3 d. The total H2 yield in the two-step process was estimated to be 4.9 mol H2/mol hexose. The major part of H2 production in the ABR-1 was due to the conversion of COD(particulate) (36%). In the ABR-2 the H2 yield was mainly due to the conversion of COD in the soluble form (76%). Based on these results MFW could be ideal substrate for H2 production in a two-step ABR processes.

  20. Effect of operational pH on biohydrogen production from food waste using anaerobic batch reactors.

    Science.gov (United States)

    Lee, Chaeyoung; Lee, Sewook; Han, Sun-Kee; Hwang, Sunjin

    2014-01-01

    This study was performed to investigate the influence of operational pH on dark H(2) fermentation of food waste by employing anaerobic batch reactors. The highest maximum H(2) yield was 1.63 mol H(2)/mol hexoseadded at operational pH 5.3, whereas the lowest maximum H(2) yield was 0.88 mol H(2)/mol hexoseadded at operational pH 7.0. With decreasing operational pH values, the n-butyrate concentration tended to increase and the acetate concentration tended to decrease. The highest hydrogen conversion efficiency of 11.3% was obtained at operational pH 5.3, which was higher than that (8.3%) reported by a previous study (Kim et al. (2011) 'Effect of initial pH independent of operational pH on hydrogen fermentation of food waste', Bioresource Technology 102 (18), 8646-8652). The new result indicates that the dark fermentation of food waste was stable and efficient in this study. Fluorescence in situ hybridization (FISH) analysis showed that Clostridium species Cluster I accounted for 84.7 and 13.3% of total bacteria at operational pH 5.3 and pH 7.0, respectively, after 48 h operation.

  1. A biodegradation and treatment of palm oil mill effluent (POME using a hybrid up-flow anaerobic sludge bed (HUASB reactor

    Directory of Open Access Journals (Sweden)

    S. A. Habeeb, AB. Aziz Abdul Latiff, Zawawi Daud, Zulkifli Ahmad

    2011-07-01

    Full Text Available Generally, anaerobic treatment has become a viable alternative in support of industrial wastewater treatment. Particularly, it is used in common to treat the palm oil mill effluent (POME. This study was carried out to assess the start-up performance of a bioreactor hybrid up-flow anaerobic sludge blanket (HUASB. Whereby, three identical reactors of 7.85-l capacity R1, R2, and R3 were operated for 57 days in order to provide two alienated comparisons. Identical operation conditions of organic loading rate (OLR and hydraulic retention time (HRT of 1.85 kg.m-3.day-1, and 2.6 day, respectively. R1 was operated in room temperature of 28±2°C, and packed with palm oil shell as filter medium support. R2 was set with room temperature but packed with course gravel. R3 was provided with water bath system to adjust its temperature at 37±1°C mesophilic, while its filter material had to be palm oil shell. During the whole operation period R3 was more efficient for organic materials, where a chemical oxygen demand (COD removal efficiency of 82% was registered, while R1 and R2 were relatively less efficient of 78%, and 76%, respectively. Furthermore, TSS removal of R3 was also higher than R1, and R2 as registered 80%, 77% and 76%, respectively. On the other hand, turbidity and colour removal were not efficient and needed a post treatment. The seeded sludge was developed in each reactor as illustrated in this paper. Therefore, all reactors show favorable performance of anaerobic treatability of POME as well as good response of microbial species development.

  2. Comparison of two mathematical models for correlating the organic matter removal efficiency with hydraulic retention time in a hybrid anaerobic baffled reactor treating molasses

    OpenAIRE

    Ghaniyari-Benis, Saeid; Martín, Antonio; Borja Padilla, Rafael; M. A. Martín; Hedayat, N.

    2012-01-01

    A modelling of the anaerobic digestion process of molasses was conducted in a 70-L multistage anaerobic biofilm reactor or hybrid anaerobic baffled reactor with six compartments at an operating temperature of 26 °C. Five hydraulic retention times (6, 16, 24, 72 and 120 h) were studied at a constant influent COD concentration of 10,000 mg/L. Two different kinetic models (one was based on a dispersion model with first-order kinetics for substrate consumption and the other based on a modificati...

  3. Early warning indicators for monitoring the process failure of anaerobic digestion system of food waste.

    Science.gov (United States)

    Li, Lei; He, Qingming; Wei, Yunmei; He, Qin; Peng, Xuya

    2014-11-01

    To determine reliable state parameters which could be used as early warning indicators of process failure due to the acidification of anaerobic digestion of food waste, three mesophilic anaerobic digesters of food waste with different operation conditions were investigated. Such parameters as gas production, methane content, pH, concentrations of volatile fatty acid (VFA), alkalinity and their combined indicators were evaluated. Results revealed that operation conditions significantly affect the responses of parameters and thus the optimal early warning indicators of each reactor differ from each other. None of the single indicators was universally valid for all the systems. The universally valid indicators should combine several parameters to supply complementary information. A combination of total VFA, the ratio of VFA to total alkalinity (VFA/TA) and the ratio of bicarbonate alkalinity to total alkalinity (BA/TA) can reflect the metabolism of the digesting system and realize rapid and effective early warning.

  4. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

    van Lier, J.B.; Tilche, A.; Ahring, Birgitte Kiær;

    2001-01-01

    The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern...... requirements. In fact, most advances were achieved during the last three decades, when high-rate reactor systems were developed and a profound insight was obtained in the microbiology of the anaerobic communities. This insight led to a better understanding of anaerobic treatment and, subsequently, to a broader...

  5. The Buoyant Filter Bioreactor: a high-rate anaerobic reactor for complex wastewater--process dynamics with dairy effluent.

    Science.gov (United States)

    Haridas, Ajit; Suresh, S; Chitra, K R; Manilal, V B

    2005-03-01

    A novel high-rate anaerobic reactor, called "Buoyant Filter Bioreactor" (BFBR), has been developed for treating lipid-rich complex wastewater. The BFBR is able to decouple the biomass and insoluble COD retention time from the hydraulic retention time by means of a granular filter bed made of buoyant polystyrene beads. Filter clogging is prevented by an automatic backwash driven by biogas release, which fluidizes the granular filter bed in a downward direction. During filter backwash, the solids captured in the filter are reintroduced into the reaction zone of the reactor. The reaction zone is provided with a mixing system, which is independent of the hydraulic retention time. The performance of a laboratory-scale BFBR was studied for the treatment of dairy effluent, chosen as a model complex wastewater. The dairy effluent was not pre-treated for fat removal. The BFBR was operated over 400 d and showed greater than 85% COD removal at 10 kg COD/(m3/d). The COD conversion to methane in the BFBR was essentially complete. The BFBR performance improved with age, and with feed containing 3200 mg COD/l, the treated effluent had 120 mg COD/l and no turbidity. The hold-up of degradable biosolids, including scum, inside the BFBR was estimated using starvation tests. When load is increased, scum accumulates inside the BFBR and then decays after undergoing change from hydrophobic to hydrophilic. This is explained as the accumulation of fat solids, its conversion to insoluble long chain fatty acids and its further solubilization and degradation.

  6. Kinetics, mass transfer and hydrodynamics in a packed bed aerobic reactor fed with anaerobically treated domestic sewage.

    Science.gov (United States)

    Fazolo, A; Pasotto, M B; Foresti, E; Zaiat, M

    2006-10-01

    This study presents an assessment of the kinetic, mass transfer and hydrodynamic parameters of a pilot-scale fixed bed reactor containing immobilized biomass in polyurethane matrices and fed with the effluent of a horizontal-flow fixed bed anaerobic reactor, which was used to treat domestic sewage. It was found that the liquid-solid and intra-particle mass transfer resistances significantly affected the overall oxygen consumption rate and that mechanical agitation could minimize such resistances. The volumetric oxygen transfer coefficient (kLa) values for superficial air velocities between 8.4 cm min(-1) and 57.0 cm min(-1) varied from 20.8 h(-1) to 58.8 h(-1) for tap water, and 16.8 h(-1) to 53.0 h(-1) for the anaerobic pre-treated effluent. The intrinsic oxygen uptake rate was estimated to be 19.9 mgO2 gVSS(-1) h(-1). A first-order kinetic model with residual concentration was considered to adequately represent the COD removal rate, whereas nitrogen conversion was considered to be well represented by a model of pseudo-first-order reaction in series. It was also found that the ammonium conversion to nitrite was the limiting step of the overall nitrogen conversion rate. The hydrodynamic behavior of the reactor was represented by three to four completely mixed reactors in series.

  7. Removal of benzene and toluene in horizontal-flow anaerobic immobilized biomass reactor (HAIBR) in the presence of sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Cattony, E.B.M.; Chinalia, F.A.; Adorno, M.A.T.; Moraes, E.M.; Zaiat, M.; Foresti, E.; Varesche, M.B.A. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Biological Processes Laboratory

    2004-07-01

    The removal of toluene and benzene from organic waste by microorganisms was tested in two bioreactors. Two horizontal-flow anaerobic immobilized biomass (HAIB) reactors were fed with Zinder medium to stimulate anaerobic sulfate-reducing bacteria (SRB). The chemical oxygen demand (COD) and sulfate analysis were assessed and acetic acid, toluene and benzene were analyzed in gas chromatography. Microbial communities were characterized by fluorescence, optical electron microscopy and molecular biology analysis. The HAIB reactors achieved steady state within 2 weeks following hydrocarbon compound amendments. Depletion of sulfate was achieved after this time, along with removal of toluene and benzene. The inflow COD for both reactors was more than 95 per cent. The HAIB reactor operated under sulfidogenic conditions. It was concluded that the use of benzene and toluene is an efficient and cost-effective method for treating contaminated water, particularly for tropical developing countries. The study emphasized the importance of SRB populations in bioreactors to degrade organic aromatics under oxygen reduced conditions. 10 refs., 4 figs.

  8. Reactor performance of a 750 m(3) anaerobic digestion plant: varied substrate input conditions impacting methanogenic community.

    Science.gov (United States)

    Wagner, Andreas Otto; Malin, Cornelia; Lins, Philipp; Gstraunthaler, Gudrun; Illmer, Paul

    2014-10-01

    A 750 m(3) anaerobic digester was studied over a half year period including a shift from good reactor performance to a reduced one. Various abiotic parameters like volatile fatty acids (VFA) (formic-, acetic-, propionic-, (iso-)butyric-, (iso-)valeric-, lactic acid), total C, total N, NH4 -N, and total proteins, as well as the organic matter content and dry mass were determined. In addition several process parameters such as temperature, pH, retention time and input of substrate and the concentrations of CH4, H2, CO2 and H2S within the reactor were monitored continuously. The present study aimed at the investigation of the abundance of acetogens and total cell numbers and the microbial methanogenic community as derived from PCR-dHPLC analysis in order to put it into context with the determined abiotic parameters. An influence of substrate quantity on the efficiency of the anaerobic digestion process was found as well as a shift from a hydrogenotrophic in times of good reactor performance towards an acetoclastic dominated methanogenic community in times of reduced reactor performance. After the change in substrate conditions it took the methano-archaeal community about 5-6 weeks to be affected but then changes occurred quickly.

  9. Combined anaerobic digestion and photocatalytic treatment of distillery effluent in fluidized bed reactors focusing on energy conservation.

    Science.gov (United States)

    Apollo, Seth; Aoyi, Ochieng

    2016-09-01

    Anaerobic digestion (AD) can remove substantial amount of organic load when applied in treating distillery effluent but it is ineffective in colour reduction. Conversely, photodegradation is effective in colour reduction but has high energy requirement. A study on the synergy of a combined AD and ultra violet (UV) photodegradation treatment of distillery effluent was carried out in fluidized bed reactors to evaluate pollution reduction and energy utilization efficiencies. The combined process improved colour removal from 41% to 85% compared to that of AD employed as a stand-alone process. An overall corresponding total organic carbon (TOC) reduction of 83% was achieved. The bioenergy production by the AD step was 14.2 kJ/g total organic carbon (TOC) biodegraded while UV lamp energy consumption was 0.9 kJ/mg TOC, corresponding to up to 100% colour removal. Electrical energy per order analysis for the photodegradation process showed that the bioenergy produced was 20% of that required by the UV lamp to photodegrade 1 m(3) of undiluted pre-AD treated effluent up to 75% colour reduction. It was concluded that a combined AD-UV system for treatment of distillery effluent is effective in organic load removal and can be operated at a reduced cost.

  10. Wastewater treatment using integrated anaerobic baffled reactor and Bio-rack wetland planted with Phragmites sp. and Typha sp.

    Science.gov (United States)

    Jamshidi, Shervin; Akbarzadeh, Abbas; Woo, Kwang-Sung; Valipour, Alireza

    2014-01-01

    The purpose of this study is to examine the potential use of anaerobic baffled reactor (ABR) followed by Bio-rack wetland planted with Phragmites sp. and Typha sp. for treating domestic wastewater generated by small communities (751 mg COD/L, 500 SCOD mg/L, 348 mg BOD5/L). Two parallel laboratory-scale models showed that the process planted with Phragmites sp. and Typha sp. are capable of removing COD by 87% & 86%, SCOD by 90% & 88%, BOD5 by 93% & 92%, TSS by 88% & 86%, TN by 79% & 77%, PO4-P by 21% & 14% at an overall HRT of 21 (843 g COD/m(3)/day & 392 g BOD5/m(3)/day) and 27 (622 g COD/m(3)/day & 302 g BOD5/m(3)/day) hours, respectively. Microbial analysis indicated a high reduction in the MPN of total coliform and TVC as high as 99% at the outlet end of the processes. The vegetated system using Phragmites sp. showed significantly greater (p Phragmites sp. indicated a higher relative growth rate (3.92%) than Typha sp. (0.90%). Microorganisms immobilized on the surface of the Bio-rack media (mean TVC: 2.33 × 10(7) cfu/cm(2)) were isolated, identified and observed using scanning electron microscopy (SEM). This study illustrated that the present integrated processes could be an ideal approach for promoting a sustainable decentralization, however, Phragmites sp. would be more efficient rather than Typha sp.

  11. Bioaugmentation of an acetate-oxidising anaerobic consortium in up-flow sludge blanket reactor subjected to high ammonia loads

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Karakashev, Dimitar Borisov; Angelidaki, Irini

    was tested. The co-cultivation in fed-batch of a fast-growing hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis) with the SAO culture was also investigated. Results obtained clearly demonstrated that bioaugmentation of SAO culture in a UASB reactor was not possible most probably due to the slow....... in association with Methanoculleus spp. strain MAB1), is an acetate oxidising methanogenic consortium that can produce methane (CH4) at high ammonia levels. In the current study the bioaugmentation of the SAO culture in a mesophilic up-flow anaerobic sludge blanket (UASB) reactor subjected to high ammonia loads...... growth of the culture. The incubation period (duration of lag+exponential phase) of SAO culture was reduced more than 30% when it was cocultivated with Methanoculleus bourgensis, in fed-batch reactors. Therefore, the bioaugmentation of the SAO culture along with Methanoculleus bourgensis in a UASB...

  12. Development and evaluation of a radial anaerobic/aerobic reactor treating organic matter and nitrogen in sewage

    Directory of Open Access Journals (Sweden)

    L. H. P. Garbossa

    2005-12-01

    Full Text Available The design and performance of a radial anaerobic/aerobic immobilized biomass (RAAIB reactor operating to remove organic matter, solids and nitrogen from sewage are discussed. The bench-scale RAAIB was divided into five concentric chambers. The second and fourth chambers were packed with polyurethane foam matrices. The performance of the reactor in removing organic matter and producing nitrified effluent was good, and its configuration favored the transfer of oxygen to the liquid mass due to its characteristics and the fixed polyurethane foam bed arrangement in concentric chambers. Partial denitrification of the liquid also took place in the RAAIB. The reactor achieved an organic matter removal efficiency of 84%, expressed as chemical oxygen demand (COD, and a total Kjeldahl nitrogen (TKN removal efficiency of 96%. Average COD, nitrite and nitrate values for the final effluent were 54 mg.L-1, 0.3 mg.L-1 and 22.1 mg.L-1, respectively.

  13. Effect of Mixing Driven by Siphon Flow: Parallel Experiments Using the Anaerobic Reactors with Different Mixing Modes

    Directory of Open Access Journals (Sweden)

    Kai-Qin Xu

    2013-08-01

    Full Text Available The effect of mixing by siphon flow on anaerobic digestion, sludge distribution and microbial community were examined in parallel experiments using a siphon-mixed reactor (SMR, an unmixed reactor (UMR and a continuously mixed reactor (CMR. The SMR performed well without the accumulation of fatty acids under COD loading rates varying from 3 to 18 kg/m3/day, while the UMR was totally acidified when the loading rate increased to 10 kg/m3/day. The methane yield of the SMR was at least 10% higher than that of the UMR, and comparable to that of the CMR. Furthermore, the SMR was found to markedly improve the dispersion of solids and reduce deposit formation compared to the UMR. Besides, during stable operation, the fatty acids level in the effluent of the SMR and UMR was lower than that in the CMR, and the archaeal community structure of the SMR was similar to that of the UMR.

  14. Temperature-based control of an anaerobic reactor using a multi-model observer-based estimator.

    Science.gov (United States)

    Morel, Emmanuel; Tartakovsky, Boris; Perrier, Michel; Guiot, Serge R

    2007-02-01

    This study presents a temperature-based control strategy for the stabilization of an anaerobic reactor during organic overloads. To prove feasibility of the proposed approach the rate of methane production was followed in batch activity tests and reactor runs during mesophilic-thermophilic transitions. Within the first 0.25-6 h of temperature augmentation, an increase in the rate of methane production was observed with higher rates measured under thermophilic (above 40 degrees C) conditions. However, 24 h after startup both in batch tests and reactor runs, the rate of methane production under thermophilic conditions was inferior to that under optimal mesophilic conditions (35 degrees C). Following these results, a control strategy based on short-term augmentation of the reactor temperature was proposed and tested in a 10 L UASB reactor. The control strategy employed a multi-model observer-based estimator to stabilize the effluent COD concentration during organic overloads. The temperature-based control resulted in an increased methanization rate and improved reactor stability overall.

  15. Evaluation of a hybrid anaerobic biofilm reactor treating winery effluents and using grape stalks as biofilm carrier.

    Science.gov (United States)

    Wahab, Mohamed Ali; Habouzit, Frédéric; Bernet, Nicolas; Jedidi, Naceur; Escudié, Renaud

    2016-01-01

    Wine production processes generate large amount of both winery wastewater and solid wastes. Furthermore, working periods, volumes and pollution loads greatly vary over the year. Therefore, it is recommended to develop a low-cost treatment technology for the treatment of winery effluents taking into account the variation of the organic loading rate (OLR). Accordingly, we have investigated the sequential operation of an anaerobic biofilm reactor treating winery effluents and using grape stalks (GSs) as biofilm carrier with an OLR ranging from 0.65 to 27 gCOD/L/d. The result showed that, during the start-up with wastewater influent, the chemical oxygen demand (COD) removal rate ranged from 83% to 93% and was about 91% at the end of the start-up period that lasted for 40 days. After 3 months of inactivity period of the reactor (no influent feeding), we have succeeded in restarting-up the reactor in only 15 days with a COD removal of 82% and a low concentration of volatile fatty acids (1 g/L), which confirms the robustness of the reactor. As a consequence, GSs can be used as an efficient carrier support, allowing a fast reactor start-up, while the biofilm conserves its activity during a non-feeding period. The proposed hybrid reactor thus permits to treat both winery effluents and GSs.

  16. Evaluating enhanced sulfate reduction and optimized volatile fatty acids (VFA) composition in anaerobic reactor by Fe (III) addition.

    Science.gov (United States)

    Liu, Yiwen; Zhang, Yaobin; Ni, Bing-Jie

    2015-02-17

    Anaerobic reactors with ferric iron addition have been experimentally demonstrated to be able to simultaneously improve sulfate reduction and organic matter degradation during sulfate-containing wastewater treatment. In this work, a mathematical model is developed to evaluate the impact of ferric iron addition on sulfate reduction and organic carbon removal as well as the volatile fatty acids (VFA) composition in anaerobic reactor. The model is successfully calibrated and validated using independent long-term experimental data sets from the anaerobic reactor with Fe (III) addition under different operational conditions. The model satisfactorily describes the sulfate reduction, organic carbon removal and VFA production. Results show Fe (III) addition induces the microbial reduction of Fe (III) by iron reducing bacteria (IRB), which significantly enhances sulfate reduction by sulfate reducing bacteria (SRB) and subsequently changes the VFA composition to acetate-dominating effluent. Simultaneously, the produced Fe (II) from IRB can alleviate the inhibition of undissociated H2S on microorganisms through iron sulfide precipitation, resulting in further improvement of the performance. In addition, the enhancement on reactor performance by Fe (III) is found to be more significantly favored at relatively low organic carbon/SO4(2-) ratio (e.g., 1.0) than at high organic carbon/SO4(2-) ratio (e.g., 4.5). The Fe (III)-based process of this work can be easily integrated with a commonly used strategy for phosphorus recovery, with the produced sulfide being recovered and then deposited into conventional chemical phosphorus removal sludge (FePO4) to achieve FeS precipitation for phosphorus recovery while the required Fe (III) being acquired from the waste ferric sludge of drinking water treatment process, to enable maximum resource recovery/reuse while achieving high-rate sulfate removal.

  17. Waste activated sludge treatment based on temperature staged and biologically phased anaerobic digestion system.

    Science.gov (United States)

    Yu, Jingwen; Zheng, Mingxia; Tao, Tao; Zuo, Jiane; Wang, Kaijun

    2013-10-01

    The concept of temperature staged and biological phased (TSBP) was proposed to enhance the performance of waste-activated sludge anaerobic digestion. Semi-continuous experiments were used to investigate the effect of temperature (35 to 70 degrees C) as well as the hydraulic retention time (HRT) (2, 4 and 6 days) on the acidogenic phase. The results showed that the solubilization degree of waste-activated sludge increased from 14.7% to 30.1% with temperature increasing from 35 to 70 degrees C, while the acidification degree was highest at 45 degrees C (17.6%), and this was quite different from the temperature impact on hydrolysis. Compared with HRT of 2 and 6 days, 4 days was chosen as the appropriate HRT because of its relatively high solubilization degree (24.6%) and acidification degree (20.1%) at 45 degrees C. The TSBP system combined the acidogenic reactor (45 degrees C, 4 days) with the methanogenic reactor (35 degrees C, 16 days) and the results showed 84.8% and 11.4% higher methane yield and volatile solid reduction, respectively, compared with that of the single-stage anaerobic digestion system with HRT of 20 days at 35 degrees C. Moreover, different microbial morphologies were observed in the acidogenic- and methanogenic-phase reactors, which resulted from the temperature control and HRT adjustment. All the above results indicated that 45 degrees C was the optimum temperature to inhibit the activity of methanogenic bacteria in the acidogenic phase, and temperature staging and phase separation was thus accomplished. The advantages of the TSBP process were also confirmed by a full-scale waste-activated sludge anaerobic digestion project which was an energy self-sufficient system.

  18. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    OpenAIRE

    Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia c...

  19. Biodegradation of high concentrations of phenol by baker’s yeast in anaerobic sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Ali Asghar Najafpoor

    2015-06-01

    Full Text Available Background: Phenol, as a pure substance, is used in many fields because of its disinfectant, germicidal, local anesthetic, and peptizing properties. Aqueous solutions of phenol are produced as waste in industries and discharged into the environment. Therefore, elevated concentrations of phenol may be found in air or water because of industrial discharge or the use of phenolic products. Method: The strains of Saccharomyces cerevisiae used in this project were natural strains previously purchased from Razavy company. They were grown at 30°C on Petri plates containing yeast extract glucose (YGC and then purified by being spread onto new plates, and isolated colonies were obtained. These colonies provided the basis of selection. Prepared strains were applied in anaerobic sequencing batch reactors (ASBRs as first seed. The experiment conditions were optimized using response surface methodology (RSM. After the determined runs were performed using Design-Expert software, data were analyzed using mentioned software as well. Results: This study evaluated the capability of baker’s yeast to remove phenol in high concentrations. The tested strains showed excellent tolerance to phenol toxicity at concentrations up to 6100 mg/L. Study of the batch degradation process showed that the phenol removal rate could exceed 99.9% in 24 hours at a concentration of 1000 mg/L. The results showed catechol is the first intermediate product of phenol degradation. In survey results of the Design–Expert software, R2 and Adeq precision were 0.97 and 25.65, respectively. Conclusion: The results demonstrated that ASBR performs robustly under variable influent concentrations of inhibitory compounds. The high removal performance despite the high phenol concentration may be a result of reactor operating strategies. Based on the progressive increase of inlet phenol concentration, allowing for an enhanced biomass acclimation in a short time, results at the microbiological levels

  20. Enhanced Biological Phosphorus Removal in Anaerobic/Aerobic Sequencing Batch Reactor Supplied with Glucose as Carbon Source

    Institute of Scientific and Technical Information of China (English)

    LIU Yanan; YU Shui-li; JING Guo-lin; ZHAO Bing-jie; GUO Si-yuan

    2005-01-01

    Phosphorus removal performance in an aerobic/aerobic sequencing batch reactor (SBR) supplied with glucose as carbon source was investigated. It was found that there was no phosphate release concomitant with the storing of poly-β-hydroxyalkanoate (PHA) during the anaerobic phase. Whereas, glycogen was soon built up followed by rapid consumption, at the same time, glucose was depleted rapidly. Based on the analysis of different fractions of phosphorus in activated sludge, the relative ratio of organically bound phosphorus in sludge changed at the end of anaerobic and aerobic phases. The ratios were 45.3% and51.8% respectively. This showed that the polyphosphate broke down during the anaerobic phase to supply part of energy for PHA synthesis. The reason why there was no phosphate release might be the biosorption effect of extracellular exopolymers (EPS). It was also proved by the analysis of EPS with scanning electron microscopy (SEM)combined with energy dispersive spectrometry (EDS). The phosphorus weight percentage of EPS at the end of anaerobic phase was 9.22%.

  1. Acetate conversion in anaerobic biogas reactors: Traditional and molecular tools for studying this important group of anaerobic microorganisms

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Mladenovska, Zuzana; Lange, Marianne;

    2000-01-01

    Different methods were applied to study the role of aceticlastic methanogens in biogas reactors treating solid waste and wastewater. We used traditional microbiological methods, immunological and 16S rRNA ribosomal probes for detection of the methanogens. Using this approach we identified the met...

  2. Anaerobic treatment of poultry mortality in a temperature-phased leachbed-UASB system.

    Science.gov (United States)

    Chen, Ten-Hong; Huang, Jiun-Lin

    2006-08-01

    Anaerobic digestion has been proposed as an alternative to the conventional disposal methods of burial, incineration, rendering and aerobic composting. A temperature-phased system consisting of one UASB (at 55 degrees C) and three leach-bed reactors (at ambient temperatures) was tested for its efficiencies in treating poultry mortality. The thermophilic UASB was difficult to start-up. It also showed signs of inhibited methanogenesis. Chemical parameters such as long chain fatty acids, volatile fatty acids and ammonia concentrations were all very high for the thermophilic UASB. Lowering its temperature to 35 degrees C enhanced its stability and improved its performances. Lowering the pH of the 55 degrees C UASB also improved its chemical oxygen demand (COD) reduction efficiency as well as its methane production rate. The results were compared to that of another similar system where the UASB reactor was maintained at 35 degrees C instead of at 55 degrees C.

  3. 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.

  4. Impact of high external circulation ratio on the performance of anaerobic reactor treating coal gasification wastewater under thermophilic condition.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Li, Kun

    2015-09-01

    A laboratory-scale external circulation anaerobic reactor (ECAR) was developed to treat actual coal gasification wastewater. The external circulation ratio (R) was selected as the main operating variable for analysis. From the results, with the hydraulic retention time of 50h, pH > 8.0 and R of 3, the COD, total phenols, volatile phenol and NH4(+)-N removal efficiencies were remarkably increased to 10 ± 2%, 22 ± 5%, 18 ± 1%, and -1 ± 2%, respectively. Besides, increasing R resulted in more transformation from bound extracellular polymeric substances (EPS) to free EPS in the liquid and the particle size distribution of anaerobic granular sludge accumulated in the middle size range of 1.0-2.5mm. Results showed the genus Saccharofermentans dominanted in the ECAR and the bacterial community shift was observed at different external circulation ratio, influencing the pollutants removal profoundly.

  5. Startup and operation of anaerobic EGSB reactor treating palm oil mill effluent

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yejian; YAN Li; CHI Lina; LONG Xiuhua; MEI Zhijian; ZHANG Zhenjia

    2008-01-01

    A bench-scale expanded granular sludge bed (EGSB) reactor was applied to the treatment of palm oil mill ettluent (POME).The reactor had been operated continuously at 35℃ for 514 d,with organic loading rate (OLR) increased from 1.45 to 17.5 kg COD/(m3·d).The results showed that the EGSB reactor had good performance in terms of COD removal on the one hand,high COD removal of 91% Was obtained at two days’ of hydraulic retention time (HRT),and the highest OLR of 17.5 kg COD/(m3·d).On the other hand,only 46% COD in raw POME Was transformed into biogas in which the methane content was about 70% (v/v).A 30-d intermittent experiment indicated that the maximum transformation potential of organic matter in raw POME into methane Was 56%.Volatile fatty acid (VFA) accumulation was observed in the later operation stage,and this Was settled by supplementing trace metal elements.On the whole,the system exhibited good stability in terms of acidity and alkalinity.Finally, the operational problems inherent in the laboratory scale experiment and the corresponding countermeasures were also discussed.

  6. Performance of an Anaerobic Baffled Filter Reactor in the Treatment of Algae-Laden Water and the Contribution of Granular Sludge

    Directory of Open Access Journals (Sweden)

    Yaqin Yu

    2014-01-01

    Full Text Available This study investigated the performance and stability of an anaerobic baffled filter reactor in the treatment of algae-laden water from Taihu Lake at several organic loading rates. The study also evaluated the capability of soft filler to train granule sludge and improve the anaerobic environment and sludge activity in the anaerobic baffled reactor (ABR, thereby enhancing the treatment efficiency. The ABR consisted of five rectangular compartments, each of which was 120 cm long, 80 cm wide, 80 cm high, and packed with soft filler. The anaerobic baffled filter reactor was found to be an efficient reactor configuration for the treatment of algae-laden water. The reactor was operated at an organic loading rate of 1.5 kg chemical oxygen demand (COD/(m3d and an ambient temperature of 30 °C; under these conditions, the COD removal efficiency was 80% and the biogas production rate was 293 mL/(Ld. Moreover, the soft filler increased the biomass retention time and decreased the rate at which solids were washed out from the reactor, promoting an improved spatial distribution of the microbial communities within the compartments. Methanoregula, Methanobacteriaceae, Methanosaeta, Methanoculleu, and Thermogymnomonas were the dominant archaeal species in each compartment during an operational period of approximately 100 days. The protease activity in the reactor decreased longitudinally down the reactor from Compartments 1 to 5, whereas the activity of coenzyme F420 increased. The soft filler played a key role in successfully treating algae-laden water with the anaerobic baffled filter reactor.

  7. The effect of pH and operation mode for COD removal of slaughterhouse wastewater with Anaerobic Batch Reactor (ABR

    Directory of Open Access Journals (Sweden)

    Maria Octoviane Dyan

    2015-01-01

    Full Text Available Disposal of industrial wastes in large quantities was not in accordance with today's standards of waste into environmental issues that must be overcome with proper treatment. Similarly, the abattoir wastewater that contains too high organic compounds and suspended solids. The amount of liquid waste disposal Slaughterhouse (SW with high volume also causes pollution. The research aim to resolve this problem by lowering the levels of BOD-COD to comply with effluent quality standard. Anaerobic process is the right process for slaughterhouse wastewater treatment because of high content of organic compounds that can be utilized by anaerobic bacteria as a growth medium. Some research has been conducted among abattoir wastewater treatment using anaerobic reactors such as ABR, UASB and ASBR. Our research focuses on the search for the optimum results decline effluent COD levels to match the quality standards limbah and cow rumen fluid with biodigester ABR (Anaerobic Batch Reactor. The variables used were PH of 6, 7, and 8, as well as the concentration ratio of COD: N is 400:7; 450:7, and 500:7. COD value is set by the addition of N derived from urea [CO(NH2 2]. COD levels will be measured daily by water displacement technique. The research’s result for 20 days seen that optimum PH for biogas production was PH 7,719 ml. The optimum PH for COD removal is PH 6, 72.39 %. The operation mode COD:N for biogas production and COD removal is 500:7, with the production value is 601 ml and COD removal value is 63.85 %. The research’s conclusion, the PH optimum for biogas production was PH 7, then the optimum PH for COD removal is PH 6. The optimum operation mode COD:N for biogas production and COD removal was 500:7

  8. Modelling anaerobic digestion in a biogas reactor: ADM1 model development with lactate as an intermediate (Part I).

    Science.gov (United States)

    Satpathy, Preseela; Biernacki, Piotr; Uhlenhut, Frank; Cypionka, Heribert; Steinigeweg, Sven

    2016-12-05

    The Anaerobic Digestion Model No. 1 (ADM1) was extended to include lactate, a crucial metabolic product during sugar fermentation. This study tests the validity of the modified ADM1 model in improving the predictions of a standard biogas reactor. This reactor was prepared in the laboratory with simple organic substrates with an intention to represent an 'average biogas plant'. Kinetic parameters were determined from a lactic acid enriched steady-state reactor. The parameters were adjusted further in order to acquire satisfying simulation results systematically with the batch experiments and then against the standard biogas reactor. Arresting methanogenesis revealed that lactate degradation occurred majorly via acetate followed by propionate, and a non-negligible proportion of butyrate too was found, which were further updated in the model. The modified ADM1 provided a successful correlation with the experimental results for the batch and continuous experiments. We justified that inclusion of lactate in the model resulted in optimized simulation for both biogas and methane content in the standard biogas reactor.

  9. Anaerobic digestion of olive oil mill effluents together with swine manure in UASB reactors

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Ahring, Birgitte Kiær; Deng, H.

    2002-01-01

    Combined anaerobic digestion of olive oil mill effluent (OME) with swine manure, was investigated. In batch experiments was shown that for anaerobic degradation of OME alone nitrogen addition was needed. A COD:N ratio in the range of 65:1 to 126:1 was necessary for the optimal degradation process...

  10. Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors

    DEFF Research Database (Denmark)

    Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

    2011-01-01

    In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/g......VS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380mL-CH4/gVS-added at the organic loading rate of 3.2gCOD/(L-reactor.d). In a UASB reactor, higher organic loading rate of 5.1gCOD/(L-reactor.d) could be tolerated, however, it resulted in a lower methane yield of 240m...

  11. Innovative method for increased methane recovery from two-phase anaerobic digestion of food waste through reutilization of acidogenic off-gas in methanogenic reactor.

    Science.gov (United States)

    Yan, Bing Hua; Selvam, Ammaiyappan; Wong, Jonathan W C

    2016-10-01

    In this study, the performance of a two-phase anaerobic digestion reactor treating food waste with the reutilization of acidogenic off-gas was investigated with the objective to improve the hydrogen availability for the methanogenic reactor. As a comparison a treatment without off-gas reutilization was also set up. Results showed that acidogenic off-gas utilization in the upflow anaerobic sludge blanket (UASB) reactor increased the methane recovery up to 38.6%. In addition, a 27% increase in the production of cumulative chemical oxygen demand (COD) together with an improved soluble microbial products recovery dominated by butyrate was observed in the acidogenic leach bed reactor (LBR) with off-gas reutilization. Of the increased methane recovery, ∼8% was contributed by the utilization of acidogenic off-gas in UASB. Results indicated that utilization of acidogenic off-gas in methanogenic reactor is a viable technique for improving overall methane recovery.

  12. Granulation of Anaerobic Sludge in Anaerobic Baffled Reactor Treating Livestock Wastewater%ABR反应器处理畜禽养殖废水中厌氧污泥颗粒化的研究

    Institute of Scientific and Technical Information of China (English)

    赵金安; 雷英春

    2015-01-01

    为了研究厌氧污泥颗粒形成过程中各因素的影响规律,本文采用厌氧折流板反应器(ABR)-改良序批式反应器(MSBR)联合工艺处理畜禽污水,通过单因素研究了影响规律,并对污泥形貌进行了表征.结果表明:有机负荷、有机底物浓度、pH 值等因素的合理控制可以促进污泥颗粒化,进而加快系统的启动. CODCr浓度为10000 mg/L 时,颗粒污泥的粒径分布为0.2~4.5 mm,显微镜低倍镜下观察到边缘非常整齐的菌团,主要菌种符合丝状产甲烷菌特征;扫描电镜清晰显示出颗粒污泥的形貌,呈球形、椭球形,表面有孔隙.启动达到设计负荷后,获得72%的CODCr去除率,产甲烷活性达到0.36 m3 CH4/kgVS.%In order to study the influence law of various factors at the formation process of anaerobic sludge granules,the anaerobic sludge granulation in anaerobic unit of the livestock wastewater was trea-ted by the combined process of anaerobic baffled reactor(ABR)and modified sequencing batch reactor (MSBR),and single factor was studied,and sludge morphology was characterized.The results show that,the granulation can be promoted by control the factors of organic loading rate(OLR),chemical ox-ygen demand(COD)concentration in the influent and pH value,and accelerate to start the ABR system. On the basis of high CODCr strength of 10 000 mg/L,the granules comprising of predominant filamen-tous methanogens present outstanding CODCr removal rate of 72% with size ranging of 0.2~4.5 mm and near spherical and ellipsoidal shape,surface porosity,and the methanogens exhibit methane yielding property of 0.36 m3 CH4/kgVS at designed organic loading rate.

  13. ANAEROBIC COMPOST CONSTRUCTED WETLANDS SYSTEM TECHNOLOGY - SITE TECHNOLOGY CAPSULE

    Science.gov (United States)

    In fall 1994, anaerobic compost wetlands in both upflow and down flow configurations were constructed adjacent to and received drainage from the Burleigh tunnel, which forms part of the Clear Creek/Central City Superfund site. The systems were operated over a 3 year period. The ...

  14. ANAEROBIC COMPOST CONSTRUCTED WETLANDS SYSTEM TECHNOLOGY - SITE ITER

    Science.gov (United States)

    In Fall 1994, anaerobic compost wetlands in both upflow and downflow configurations were constructed adjacent to and received drainage from the Burleigh Tunnel, which forms part of the Clear Creek/Central City Superfund site. The systems were operated over a 3 year period. The e...

  15. Degradation of phenol in an upflow anaerobic sludge blanket(UASB) reactor at ambient temperatureKE

    Institute of Scientific and Technical Information of China (English)

    KE Shui-zhou1; SHI Zhou; ZHANG Tong; Herbert H. P. FANG

    2004-01-01

    A synthetic wastewater containing phenol as sole substrate was treated in a 2.8 L upflow anaerobic sludge blanket(UASB) reactor at ambient temperature. The operation conditions and phenol removal efficiency were discussed, microbial population in the UASB sludge was identified based on DNA cloning, and pathway of anaerobic phenol degradation was proposed. Phenol in wastewater was degraded in an UASB reactor at loading rate up to 18 gCOD/(L·d), With a 1:1 recycle ratio, at 26(1℃, pH 7.0-7.5. An UASB reactor was able to remove 99% of phenol up to 1226 mg/L in wastewater with 24 h of hydraulic retention time(HRT). For HRT below 24 h, phenol degradation efficiency decreased with HRT, from 95.4% at 16 h to 93.8% at 12 h. It further deteriorated to 88.5% when HRT reached 8 h. When the concentration of influent phenol of the reactor was 1260 mg/L(corresponding COD 3000 mg/L), with the HRT decreasing(from 40 h to 4 h, corresponding COD loading increasing), the biomass yields tended to increase from 0.265 to 3.08 g/(L·d). While at 12 h of HRT, the biomass yield was lower. When HRT was 12 h, the methane yield was 0.308 L/(gCOD removed), which was the highest. Throughout the study, phenol was the sole organic substrate. The effluent contained only residual phenol without any detectable intermediates, such as benzoate, 4-hydrobenzoate or volatile fatty acids(VFAs). Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H2/CO2. Methanogens lastly converted acetate and H2/CO2 to methane. The role of epsilon-Proteobacteria was, however, unsure.

  16. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  17. Effects of Temperature and Hydraulic Residence Time (HRT) on Treatment of Dilute Wastewater in a Carrier Anaerobic Baffled Reactor

    Institute of Scientific and Technical Information of China (English)

    HUA-JUN FENG; LI-FANG HU; DAN SHAN; CHENG-RAN FANG; DONG-SHENG SHEN

    2008-01-01

    To examine the effect of hydraulic residence time (HRT) on the performance and stability,to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor (CABR),and hence to gain a deeper insight into microbial responses to hydraulic shocks on the base of the relationships among macroscopic performance,catabolic intermediate,and microcosmic alternation.Methods COD,VFAs,and microbial activity were detected with constant feed strength (300 mg/L) at different HRTs (9-18 h) and temperatures (10℃-28℃) in a CABR.Results The removal efficiencies declined with the decreases of HRTs and temperatures.However,the COD removal load was still higher at short HRT than at long HRT.Devastating reactor performance happened at temperature of 10℃ and at HRT of 9 h.HRTs had effect on the VFAs in the reactor slightly both at high and low temperatures,but the reasons differed from each other.Microbial activity was sensitive to indicate changes of environmental and operational parameters in the reactor.Conclusion The CABR offers to certain extent an application to treat dilute wastewater under a hydraulic-shock at temperatures from 10℃ to 28℃.

  18. First-order kinetics of landfill leachate treatment in a pilot-scale anaerobic sequence batch biofilm reactor.

    Science.gov (United States)

    Contrera, Ronan Cleber; da Cruz Silva, Katia Cristina; Morita, Dione Mari; Domingues Rodrigues, José Alberto; Zaiat, Marcelo; Schalch, Valdir

    2014-12-01

    This paper reports the kinetics evaluation of landfill leachate anaerobic treatment in a pilot-scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR). The experiment was carried out at room temperature (23.8 ± 2.1 °C) in the landfill area in São Carlos-SP, Brazil. Biomass from the bottom of a local landfill leachate stabilization pond was used as inoculum. After acclimated and utilizing leachate directly from the landfill, the AnSBBR presented efficiency over 70%, in terms of COD removal, with influent COD ranging from 4825 mg L(-1) to 12,330 mg L(-1). To evaluate the kinetics of landfill leachate treatment, temporal profiles of CODFilt. concentration were performed and a first-order kinetics model was adjusted for substrate consumption, obtaining an average k1 = 4.40 × 10(-5) L mgTVS(-1) d(-1), corrected to 25 °C. Considering the temperature variations, a temperature-activity coefficient θ = 1.07 was obtained. Statistical "Randomness" and "F" tests were used to successfully validate the model considered. Thus, the results demonstrate that the first-order kinetic model is adequate to model the anaerobic treatment of the landfill leachate in the AnSBBR.

  19. Anaerobic Treatment of Agricultural Residues and Wastewater - Application of High-Rate Reactors

    OpenAIRE

    Parawira, Wilson

    2004-01-01

    The production of methane via anaerobic digestion of agricultural residues and industrial wastewater would benefit society by providing a clean fuel from renewable feedstocks. This would reduce the use of fossil-fuel-derived energy and reduce environmental impact, including global warming and pollution. Limitation of carbon dioxide and other emissions through emission regulations, carbon taxes, and subsidies on biomass energy is making anaerobic digestion a more attractive and competitive tec...

  20. Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2015-02-01

    High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L during 30 days, resulting in an average recovery rate of 80 g-N/m(2)/d. Meanwhile, a maximum power density of 0.71±0.5 W/m(2) was generated at 2.85 A/m(2). Both current driven NH4(+) migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMDC performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation.

  1. External fuel thermionic reactor system.

    Science.gov (United States)

    Mondt, J. F.; Peelgren, M. L.

    1971-01-01

    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  2. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Neil Todreas; Pavel Hejzlar

    2008-06-30

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  3. Factors affecting biological denitrifying dephosphatation in anaerobic/anoxic/aerobic sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor ( SBR ).The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anacrobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.

  4. Biocatalytic methanation of hydrogen and carbon dioxide in an anaerobic three-phase system.

    Science.gov (United States)

    Burkhardt, M; Koschack, T; Busch, G

    2015-02-01

    A new type of anaerobic trickle-bed reactor was used for biocatalytic methanation of hydrogen and carbon dioxide under mesophilic temperatures and ambient pressure in a continuous process. The conversion of gaseous substrates through immobilized hydrogenotrophic methanogenic archaea in a biofilm is a unique feature of this type of reactor. Due to the formation of a three-phase system on the carrier surface and operation as a plug flow reactor without gas recirculation, a complete reaction could be observed. With a methane concentration higher than c(CH4) = 98%, the product gas exhibits a very high quality. A specific methane production of P(CH4) = 1.49 Nm(3)/(m(3)(SV) d) was achieved at a hydraulic loading rate of LR(H2) = 6.0 Nm(3)/(m(3)(SV) d). The relation between trickle flow through the reactor and productivity could be shown. An application for methane enrichment in combination with biogas facilities as a source of carbon dioxide has also been positively proven.

  5. Simultaneous biohydrogen production and wastewater treatment in biofilm configured anaerobic periodic discontinuous batch reactor using distillery wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Venkata Mohan, S.; Mohanakrishna, G.; Ramanaiah, S.V.; Sarma, P.N. [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India)

    2008-01-15

    Biohydrogen (H{sub 2}) production with simultaneous wastewater treatment was studied in anaerobic sequencing batch biofilm reactor (AnSBBR) using distillery wastewater as substrate at two operating pH values. Selectively enriched anaerobic mixed consortia sequentially pretreated with repeated heat-shock (100{sup o}C; 2 h) and acid (pH -3.0; 24 h) methods, was used as parent inoculum to startup the bioreactor. The reactor was operated at ambient temperature (28{+-}2 {sup circle} C) with detention time of 24 h in periodic discontinuous batch mode. Experimental data showed the feasibility of hydrogen production along with substrate degradation with distillery wastewater as substrate. The performance of the reactor was found to be dependent on the operating pH. Adopted acidophilic microenvironment (pH 6.0) favored H{sub 2} production (H{sub 2} production rate - 26 mmol H{sub 2}/day; specific H{sub 2} production - 6.98 mol H{sub 2}/kg COD{sub R}-day) over neutral microenvironment (H{sub 2} production rate - 7 mmol H{sub 2}/day; specific H{sub 2} production - 1.63 mol H{sub 2}/kg COD{sub R}-day). However, COD removal efficiency was found to be effective in operated neutral microenvironment (pH 7 - 69.68%; pH 6.0 - 56.25%). The described process documented the dual benefit of renewable energy generation in the form of H{sub 2} with simultaneous wastewater treatment utilizing it as substrate. (author)

  6. Combined carbon and nitrogen removal in integrated anaerobic/anoxic sludge bed reactors for the treatment of domestic sewage

    NARCIS (Netherlands)

    Kassab, G.

    2009-01-01

    The main objective of this research is to assess the applicability and effectiveness of integrating anaerobic digestion and denitrification processes in a single sludge system. The integrated concept is of particular interest for the treatment of highstrength domestic wastewater and is accomplished

  7. Utilization of high-strength wastewater for the production of biogas as a renewable energy source using hybrid upflow anaerobic sludge blanket (HUASB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shivayogimath, C.B.; Ramanujam, T.K.

    1998-07-01

    Anaerobic digestion of distillery spentwash, a high-strength wastewater, was studied using a hybrid upflow anaerobic sludge blanket (HUASB) reactor for 240 days under ambient conditions. The HUASB reactor combined an open volume in the bottom two-thirds of the reactor for sludge blanket and polypropylene pall rings packing in the upper one-third of the reactor. The aim of the study was to achieve optimum biogas production and waste treatment. Using non-granular anaerobic sewage sludge as seed, the start-up of the HUASB reactor was successfully completed, with the production of active bacterial granules of 1--2 mm size, within 90 days. Examination of the bacterial granules under scanning electron microscope (SEM) revealed that Methanothrix like microorganisms were the dominant species besides Methanosarcina. An organic loading of 24 kg COD/m{sup 3}d at a low hydraulic retention time (HRT) of 6 hours was achieved with 82% reduction in COD. Biogas with high methane content (80%) was produced at these loadings. The specific biogas yield was 0.36 m{sup 3} CH{sub 4}/kg COD. Packing in the upper third of the reactor was very efficient as a gas-solid separator (GSS); and in addition it retained the biomass.

  8. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2013-06-01

    Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.

  9. Morphological study of biomass during the start-up period of a fixed-bed anaerobic reactor treating domestic sewage

    Directory of Open Access Journals (Sweden)

    Cláudio Antonio Andrade Lima

    2005-09-01

    Full Text Available This work focused on a morphological study of the microorganisms attached to polyurethane foam matrices in a horizontal-flow anaerobic immobilized biomass (HAIB reactor treating domestic sewage. The experiments consisted of monitoring the biomass colonization process of foam matrices in terms of the amount of retained biomass and the morphological characteristics of the cells attached to the support during the start-up period. Non-fluorescent rods and cocci were found to predominate in the process of attachment to the polyurethane foam surface. From the 10th week of operation onwards, an increase was observed in the morphological diversity, mainly due to rods, cocci, and Methanosaeta-like archaeal cells. Hydrodynamic problems, such as bed clogging and channeling occurred in the fixed-bed reactor, mainly due to the production of extracellular polymeric substances and their accumulation in the interstices of the bed causing a gradual deterioration of its performance, which eventually led to the system's collapse. These results demonstrated the importance and usefulness of monitoring the dynamics of the formation of biofilm during the start-up period of HAIB reactors, since it allowed the identification of operational problems.Este trabalho apresenta um estudo morfológico de microrganismos aderidos à espuma de poliuretano em reator anaeróbio horizontal de leito fixo (RAHLF, aplicado ao tratamento de esgoto sanitário. O processo de colonização do suporte pela biomassa anaeróbia e as características morfológicas das células aderidas foram monitorados durante o período de partida do reator. Bacilos e cocos não fluorescentes foram predominantes no processo de aderência direta à espuma de poliuretano. Aumento na diversidade biológica foi observado a partir da 10ª semana de operação do reator, com predominância de bacilos, cocos e arqueas metanogênicas semelhantes a Methanosaeta. Problemas hidrodinâmicos, tais como formação de

  10. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1988-01-01

    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  11. Kraft pulp and paper mill wastewater treatment using fixed bed anaerobic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Damianovic, M. H. R. Z; Ruas, D.; Pires, E. C.; Foresti, E.

    2009-07-01

    The effluents of pulp mills contain a myriad of toxic compounds, biodegradable organic matter and sulfur compounds. to decrease the amount of fresh water required for pulp and paper production closed circuits are in use, however, higher concentrations of slat, as oxidized sulfur compounds, are encountered in the wastewaters. energy costs and new environmental concerns are motivating the use of anaerobic pretreatment as a way to decrease energy expenditure in the treatment plant together with lower sludge production. In anaerobic environment, the organic matter removal can follow methanogenic or sulfidogenic paths and with the latter simultaneous reduction of the oxidized sulfur compounds also occurs. (Author)

  12. 16S ribosomal DNA clone libraries to reveal bacterial diversity in anaerobic reactor-degraded tetrabromobisphenol A.

    Science.gov (United States)

    Peng, Xingxing; Zhang, Zaili; Zhao, Ziling; Jia, Xiaoshan

    2012-05-01

    Microorganisms able to rapidly degrade tetrabromobisphenol A (TBBPA) were domesticated in an anaerobic reactor and added to gradually increased concentrations of TBBPA. After 240 days of domestication, the degradation rate reached 96.0% in cultivated batch experiments lasting 20 days. The optimum cultivating temperature and pH were 30°C and 7.0. The bacterial community's composition and diversity in the reactor was studied by comparative analysis with 16S ribosomal DNA clone libraries. Amplified rDNA restriction analysis of 200 clones from the library indicate that the rDNA richness was high (Coverage C 99.5%) and that evenness was not high (Shannon-Weaver index 2.42). Phylogenetic analysis of 63 bacterial sequences from the reactor libraries demonstrated the presence of Betaproteobacteria (33.1%), Gammaproteobacteria (18.7%), Bacteroidetes (13.9%), Firmicutes (11.4%), Chloroflexi (3.6%), Actinobacteria (0.6%), the candidate division TM7 (4.2%) and other unknown, uncultured bacterial groups (14.5%). Comamonas, Achromobacter, Pseudomonas and Flavobacterium were the dominant types.

  13. Assessment of anaerobic bacterial diversity and its effects on anaerobic system stability and the occurrence of antibiotic resistance genes.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2016-05-01

    This study evaluated the link between anaerobic bacterial diversity and, the biodegradation of antibiotic combinations and assessed how amending antibiotic combination and increasing concentration of antibiotics in a stepwise fashion influences the development of resistance genes in anaerobic reactors. The biodegradation, sorption and occurrence of the known antibiotic resistance genes (ARGs) of erythromycin and tetracycline were investigated using the processes of UV-HPLC and qPCR analysis respectively. Ion Torrent sequencing was used to detect microbial community changes in response to the addition of antibiotics. The overall results indicated that changes in the structure of a microbial community lead to changes in biodegradation capacity, sorption of antibiotics combinations and occurrence of ARGs. The enhanced biodegradation efficiency appeared to generate variations in the structure of the bacterial community. The results suggested that controlling the ultimate Gram-negative bacterial community, especially Acinetobacter-related populations, may promote the successful biodegradation of antibiotic combinations and reduce the occurrence of ARGs.

  14. Transients in reactors for power systems compensation

    Science.gov (United States)

    Abdul Hamid, Haziah

    This thesis describes new models and investigations into switching transient phenomena related to the shunt reactors and the Mechanically Switched Capacitor with Damping Network (MSCDN) operations used for reactive power control in the transmission system. Shunt reactors and MSCDN are similar in that they have reactors. A shunt reactor is connected parallel to the compensated lines to absorb the leading current, whereas the MSCDN is a version of a capacitor bank designed as a C-type filter for use in the harmonic-rich environment. In this work, models have been developed and transient overvoltages due to shunt reactor deenergisation were estimated analytically using MathCad, a mathematical program. Computer simulations used the ATP/EMTP program to reproduce both single-phase and three-phase shunt reactor switching at 275 kV operational substations. The effect of the reactor switching on the circuit breaker grading capacitor was also examined by considering various switching conditions.. The main original achievement of this thesis is the clarification of failure mechanisms occurring in the air-core filter reactor due to MSCDN switching operations. The simulation of the MSCDN energisation was conducted using the ATP/EMTP program in the presence of surge arresters. The outcome of this simulation shows that extremely fast transients were established across the air-core filter reactor. This identified transient event has led to the development of a detailed air-core reactor model, which accounts for the inter-turn RLC parameters as well as the stray capacitances-to-ground. These parameters are incorporated into the transient simulation circuit, from which the current and voltage distribution across the winding were derived using electric field and equivalent circuit modelling. Analysis of the results has revealed that there are substantial dielectric stresses imposed on the winding insulation that can be attributed to a combination of three factors. (i) First, the

  15. Effect of redox mediator, AQDS, on the decolourisation of a reactive azo dye containing triazine group in a thermophilic anaerobic EGSB reactor

    NARCIS (Netherlands)

    Bezerra Dos Santos, A.; Cervantes-Carillo, F.J.; Yaya Beas, R.E.; Lier, van J.B.

    2003-01-01

    The feasibility of thermophilic (55 degreesC) anaerobic treatment applied to colour removal of a triazine contained reactive azo dye was investigated in two 0.531 expanded granular sludge blanket (EGSB) reactors in parallel at a hydraulic retention time (HRT) of 10 h. Generally, this group of azo dy

  16. Anaerobic digestion of cassava wastewater in fixed bed reactor using bamboo medium support; Digestao anaerobica de agua residuaria de fecularia em reator de leito fixo utilizando meio suporte de aneis de bambu

    Energy Technology Data Exchange (ETDEWEB)

    Watthier, Elisangela; Andreani, Cristiane L.; Silva, Jefferson L.G. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil)], E-mail: eliswa@hotmail.com; Gomes, Simone D. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Dept. de Recursos Hidricos e Saneamento Ambiental

    2012-11-01

    Cassava wastewater causes damage to the environment due to high organic loads and presence of cyanide and hydrocyanic acid. An alternative treatment anaerobic which add value for biogas production. To allow use of higher load sand reducing the TDH support means are used. This study aimed to evaluate the performance of the anaerobic treatment of liquid effluent of cassava industry, using bamboo as support media. The wastewater used was derived from starch factory located in Toledo. Was used PVC reactor with a diameter of 15 cm and length 90 cm. Were used as support means 52 bamboo rings and useful reactor volume 61. A total of 13 load increasing, from 1,675 to 15.158 g.L{sup -1}.d{sup -1}, until reaching the maximum load bearable. For each load data was collected for 15 days by daily samples at entrance and exit of the reactors. The samples were analyzed: DQO, alkalinity, volatile acidity and biogas production. There was a system instability in 12,394 g.L{sup -1}.d{sup -1}, with values of AV/AT above 0.5, but the system began to show signs of stability in the next load. The reactor showed biogas production up 1.57 L.L{sup -1}.d{sup -1}. (author)

  17. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue

    2016-01-01

    of interaction, which have not been sufficiently studied so far. It is therefore important to understand how choosing operational parameters can influence reactor performances. The current study highlights the interaction offermentative bacteria and exoelectrogens in the integrated system....... in an integrated system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) for waste activated sludge (WAS). Microbial communities in integrated system would build a thorough energetic and metabolic interaction network regarding fermentation communities and electrode respiring communities...... investigated the interaction of fermentation communities and electrode respiring communities in an integrated system of WAS fermentation and MEC for hydrogen recovery. A high energy recovery was achieved in the MECs feeding WAS fermentation liquid through alkaline pretreatment. Some anaerobes belonging...

  18. Effects of pH, acidity and alkalinity on the microbiota activity of an anaerobic sludge blanket reactor (UASB treating pigmanure effluents

    Directory of Open Access Journals (Sweden)

    Fabricio Moterani

    2009-12-01

    Full Text Available The anaerobic processes used for treating wastewater have been often applied mainly for optimizing treatment systems. Among many of these systems, the UASB is one of the most successfully used. This type of reactor presents a good condition for microorganisms development, and therefore, for organic matter degradation. As a result, the goal of this research was to evaluate the effect of parameters, such as: temperature, pH, acidity and alkalinity on the microorganisms consortia, acclimatized in an UASB reactor, and simultaneously, observing the sludge morphology through a scanning electronic microscopy (SEM, in order to identify the response of the bacteria consortia under this environmental circumstances. The biomass operated under a mesophilic temperature, varying from 190C to 210C. The maximum concentration of volatile acids was 100 mg L-1, and the volumetric organic loading rate was 59 kgCOD m-3d-1. The total alkalinity concentration values were between 2500 and 5550 mgCaCO3 L-1. The average pH value of the sludge was 7.3. Under these conditions it was observed the development of a well acclimatized granular biomass, composed mainly of filamentous bacteria.

  19. Enzymatic Antioxidant Systems in Early Anaerobes: Theoretical Considerations

    Science.gov (United States)

    Ślesak, Ireneusz; Ślesak, Halina; Zimak-Piekarczyk, Paulina; Rozpądek, Piotr

    2016-05-01

    It is widely accepted that cyanobacteria-dependent oxygen that was released into Earth's atmosphere ca. 2.5 billion years ago sparked the evolution of the aerobic metabolism and the antioxidant system. In modern aerobes, enzymes such as superoxide dismutases (SODs), peroxiredoxins (PXs), and catalases (CATs) constitute the core of the enzymatic antioxidant system (EAS) directed against reactive oxygen species (ROS). In many anaerobic prokaryotes, the superoxide reductases (SORs) have been identified as the main force in counteracting ROS toxicity. We found that 93% of the analyzed strict anaerobes possess at least one antioxidant enzyme, and 50% have a functional EAS, that is, consisting of at least two antioxidant enzymes: one for superoxide anion radical detoxification and another for hydrogen peroxide decomposition. The results presented here suggest that the last universal common ancestor (LUCA) was not a strict anaerobe. O2 could have been available for the first microorganisms before oxygenic photosynthesis evolved, however, from the intrinsic activity of EAS, not solely from abiotic sources.

  20. Microbial characterization and degradation of linear alkylbenzene sulfonate in an anaerobic reactor treating wastewater containing soap powder.

    Science.gov (United States)

    Carosia, Mariana Fronja; Okada, Dagoberto Yukio; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2014-09-01

    The aim of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) in an anaerobic fluidized bed reactor (AFBR) treating wastewater containing soap powder as LAS source. At Stage I, the AFBR was fed with a synthetic substrate containing yeast extract and ethanol as carbon sources, and without LAS; at Stage II, soap powder was added to this synthetic substrate obtaining an LAS concentration of 14 ± 3 mg L(-1). The compounds of soap powder probably inhibited some groups of microorganisms, increasing the concentration of volatile fatty acids (VFA) from 91 to 143 mg HAc L(-1). Consequently, the LAS removal rate was 48 ± 10% after the 156 days of operation. By sequencing, 16S rRNA clones belonging to the phyla Proteobacteria and Synergistetes were identified in the samples taken at the end of the experiment, with a remarkable presence of Dechloromonas sp. and Geobacter sp.

  1. The role of acid incubation in rapid immobilization of hydrogen-producing culture in anaerobic upflow column reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhen-Peng; Tay, Joo-Hwa [School of Civil and Environmental Engineering, Nanyang Technological University (Singapore); Institute of Environmental Science and Engineering, Nanyang Technological University (Singapore); Show, Kuan-Yeow [Faculty of Science, Engineering and Technology, University Tunku Abdul Rahman, 31900 Kampar, Perak (Malaysia); Liang, David Tee [Institute of Environmental Science and Engineering, Nanyang Technological University (Singapore); Lee, Duu-Jong [Department of Chemical Engineering, National Taiwan University, Taipei 10617 (China); Su, Ay [Department of Mechanical Engineering, Fuel Cell Center, Yuan-Ze University, Taoyuan 320 (China)

    2008-10-15

    An approach of acidification was examined on formation of hydrogen-producing granules and biofilms in upflow column-shaped reactors. The reactors were fed with synthetic glucose wastewater and operated at 37 C and pH 5.5. The acclimated anaerobic culture was inoculated in four reactors designated R1, R2, R3 and R4, with R3 and R4 filled with granular activated carbon as support medium. To unveil the roles of acidification, microbial culture in R2 and R3 was subject to an acid incubation for 24 h by shifting the culture pH from 5.5 to 2.0. The experimental results suggested that the acidification substantially accelerated microbial granulation, but not biofilm formation. Microbial activities were inhibited by the acid incubation for about 78 h, resulting in the retarded formation of biofilms of the acidified culture. Reducing culture pH resulted in improvement in cell surface physicochemical properties favoring microbial adhesion and immobilization. Zeta potential increased from -25.3 mV to 11.9 mV, hydrophobicity in terms of contact angle improved from 31 to 38 and production of extracellular polymers increased from 66 mg/g-VSS to 136 mg/g-VSS. As a result of the formation of granules and biofilms, high hydrogen production rates of 6.98 and 7.49 L/L h were achieved in granule-based and biofilm-based reactors, respectively. It is concluded that acid incubation is an efficient means to initiate the rapid formation of granules by regulating the surface characteristics of microbial culture. The use of support media as starting nuclei may result in rapid formation of biofilms without the acidification. (author)

  2. Evaluation of the microbial diversity in a horizontal-flow anaerobic immobilized biomass reactor treating linear alkylbenzene sulfonate.

    Science.gov (United States)

    Duarte, I C S; Oliveira, L L; Saavedra, N K D; Fantinatti-Garboggini, F; Oliveira, V M; Varesche, M B A

    2008-06-01

    The purpose of this work was to assess the degradation of linear alkylbenzene sulfonate (LAS) in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor. The reactor was filled with polyurethane foam where the sludge from a sanitary sewage treatment was immobilized. The hydraulic detention time (HDT) used in the experiments was of 12 h. The reactor was fed with synthetic substrate (410 mg l(-1) of meat extract, 115 mg l(-1) of starch, 80 mg l(-1) of saccharose, 320 mg l(-1) of sodium bicarbonate and 5 ml l(-1) of salt solution) in the following stages of operation: SI-synthetic substrate, SII-synthetic substrate with 7 mg l(-1) of LAS, SIII-synthetic substrate with 14 mg l(-1) of LAS and SIV-synthetic substrate containing yeast extract (substituting meat extract) and 14 mg l(-1) of LAS, without starch. At the end of the experiment (313 days) a degradation of approximately 35% of LAS was achieved. The higher the concentration of LAS, the greater the amount of foam for its adsorption. This is necessary because the isotherm of LAS adsorption in the foam is linear for the studied concentrations (2 to 50 mg l(-1)). Microscopic analyses of the biofilm revealed diverse microbial morphologies, while Denaturing Gradient Gel Eletrophoresis (DGGE) profiling showed variations in the population of total bacteria and sulphate-reducing bacteria (SRB). The 16S rRNA gene sequencing and phylogenetic analyses revealed that the members of the order Clostridiales were the major components of the bacterial community in the last reactor operation step.

  3. Biotic and abiotic dynamics of a high solid-state anaerobic digestion box-type container system.

    Science.gov (United States)

    Walter, Andreas; Probst, Maraike; Hinterberger, Stephan; Müller, Horst; Insam, Heribert

    2016-03-01

    A solid-state anaerobic digestion box-type container system for biomethane production was observed in 12 three-week batch fermentations. Reactor performance was monitored using physico-chemical analysis and the methanogenic community was identified using ANAEROCHIP-microarrays and quantitative PCR. A resilient community was found in all batches, despite variations in inoculum to substrate ratio, feedstock quality, and fluctuating reactor conditions. The consortia were dominated by mixotrophic Methanosarcina that were accompanied by hydrogenotrophic Methanobacterium, Methanoculleus, and Methanocorpusculum. The relationship between biotic and abiotic variables was investigated using bivariate correlation analysis and univariate analysis of variance. High amounts of biogas were produced in batches with high copy numbers of Methanosarcina. High copy numbers of Methanocorpusculum and extensive percolation, however, were found to negatively correlate with biogas production. Supporting these findings, a negative correlation was detected between Methanocorpusculum and Methanosarcina. Based on these results, this study suggests Methanosarcina as an indicator for well-functioning reactor performance.

  4. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, L. C.; Campos, R.; Pinheiro, H. M.; Lopes, A.; Ferra, M. I.

    2009-07-01

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  5. Decoloration of textile wastewater by means of a fluidized-bed loop reactor and immobilized anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Georgiou, D. [Department of Environmental Engineering, Demokritos University of Thrace, 67100 Xanthi (Greece)]. E-mail: dgeorgio@env.duth.gr; Aivasidis, A. [Department of Environmental Engineering, Demokritos University of Thrace, 67100 Xanthi (Greece)

    2006-07-31

    Textile wastewater was treated by means of a fluidized-bed loop reactor and immobilized anaerobic bacteria. The main target of this treatment was decoloration of the wastewater and transformation of the non-biodegradable azo-reactive dyes to the degradable, under aerobic biological conditions, aromatic amines. Special porous beads (Siran'' (registered)) were utilized as the microbial carriers. Acetic acid solution, enriched with nutrients and trace elements, served both as a pH-regulator and as an external substrate for the growth of methanogenic bacteria. The above technique was firstly applied on synthetic wastewater (an aqueous solution of a mixture of different azo-reactive dyes). Hydraulic residence time was gradually decreased from 24 to 6 h over a period of 3 months. Full decoloration of the wastewater could be achieved even at such a low hydraulic residence time (6 h), while methane-rich biogas was also produced. The same technique was then applied on real textile wastewater with excellent results (full decoloration at a hydraulic residence time of 6 h). Furthermore, the effluent proved to be highly biodegradable by aerobic microbes (activated-sludge). Thus, the above-described anaerobic/aerobic biological technique seems to be a very attractive method for treating textile wastewater since it is cost-effective and environment-friendly.

  6. Optimizing the performance of a reactor by reducing the retention time and addition of glycerin for anaerobically digesting manure.

    Science.gov (United States)

    Timmerman, Maikel; Schuman, Els; van Eekert, Miriam; van Riel, Johan

    2015-01-01

    Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on manure (>90%); however, the methane yields of manure are less compared to coproducts, which is one of the reasons for manure-based biogas plants often being economically non-viable. Therefore, it is essential to begin increasing the efficiency of these biogas plants. This study investigated the effect of decreasing retention time and introducing a moderate amount of glycerin on the biogas production as methods to improve efficiency. An experiment has been conducted with two different manure types in four biogas reactors. The results of the study demonstrated that, first, it was possible to decrease the retention time to 10-15 days; however, the effect on biogas production varied per manure type. Secondly, the biogas production almost triples at a retention time of 15.6 days with an addition of 4% glycerin. The relative production-enhancing effect of glycerin did not vary significantly with both manure types. However, the absolute production-enhancing effect of glycerin differed per manure type since the biogas production per gram VS differed per manure type. Thirdly, the positive effect of the glycerin input declines with shorter retention times. Therefore, the effect of glycerin addition depends on the manure type and retention time.

  7. Combination of batch experiments with continuous reactor data for ADM1 calibration: application to anaerobic digestion of pig slurry.

    Science.gov (United States)

    Girault, R; Rousseau, P; Steyer, J P; Bernet, N; Béline, F

    2011-01-01

    Modelling anaerobic digestion processes is a key aspect of studying and optimizing digesters and related waste streams. However, for the satisfactory prediction of biogas production and effluent characteristics, some parameters have to be calibrated according to the characteristics of the substrates. This article describes a calibration procedure for the IWA 'Anaerobic Digestion Model no. 1' applied to the modelling of a digester for treatment of pig slurry. The most sensitive parameters were selected and calibrated combining results from a continuous digester and from batch trials run with the sludge sampled from the digester and the addition of specific substrates. According to the sensitivity analysis, acetoclastic methanogenesis, acetogenesis of propionate and acidogenesis of sugars were identified as the main sensitive steps in our case. The calibration procedure led us to modify slightly acetogenesis of propionate kinetic. However, acetoclastic methanogenesis and acidogenesis of sugars kinetics were significantly reduced by decreasing km and increasing Ks. Indeed, for instance, a decrease of km_ac from 8 to 7 day(-1) combined with an increase of Ks_ac from 0.15 to 1.5 kgCOD/m3 was necessary. After calibration, ADM1 provides an accurate simulation of the continuous reactor results.

  8. Monitoring bacterial and archaeal community shifts in a mesophilic anaerobic batch reactor treating a high-strength organic wastewater.

    Science.gov (United States)

    Lee, Changsoo; Kim, Jaai; Shin, Seung Gu; Hwang, Seokhwan

    2008-09-01

    Shifts in bacterial and archaeal communities, associated with changes in chemical profiles, were investigated in an anaerobic batch reactor treating dairy-processing wastewater prepared with whey permeate powder. The dynamics of bacterial and archaeal populations were monitored by quantitative real-time PCR and showed good agreement with the process data. A rapid increase in bacterial populations and a high rate of substrate fermentation were observed during the initial period. Growth and regrowth of archaeal populations occurred with biphasic production of methane, corresponding to the diauxic consumption of acetate and propionate. Bacterial community structure was examined by denaturing gel gradient electrophoresis (DGGE) targeting 16S rRNA genes. An Aeromonas-like organism was suggested to be mainly responsible for the rapid fermentation of carbohydrate during the initial period. Several band sequences closely related to the Clostridium species, capable of carbohydrate fermentation, lactate or ethanol fermentation, and/or homoacetogenesis, were also detected. Statistical analyses of the DGGE profiles showed that the bacterial community structure, as well as the process performance, varied with the incubation time. Our results demonstrated that the bacterial community shifted, reflecting the performance changes and, particularly, that a significant community shift corresponded to a considerable process event. This suggested that the diagnosis of an anaerobic digestion process could be possible by monitoring bacterial community shifts.

  9. Analysis of methanogenic activity in a thermophilic-dry anaerobic reactor: use of fluorescent in situ hybridization.

    Science.gov (United States)

    Montero, B; García-Morales, J L; Sales, D; Solera, R

    2009-03-01

    Methanogenic activity in a thermophilic-dry anaerobic reactor was determined by comparing the amount of methane generated for each of the organic loading rates with the size of the total and specific methanogenic population, as determined by fluorescent in situ hybridization. A high correlation was evident between the total methanogenic activity and retention time [-0.6988Ln(x)+2.667] (R(2) 0.8866). The total methanogenic activity increased from 0.04x10(-8) mLCH(4) cell(-1)day(-1) to 0.38x10(-8) mLCH(4) cell(-1)day(-1) while the retention time decreased, augmenting the organic loading rates. The specific methanogenic activities of H(2)-utilizing methanogens and acetate-utilizing methanogens increased until they stabilised at 0.64x10(-8) mLCH(4) cell(-1)day(-1) and 0.33x10(-8) mLCH(4) cell(-1)day(-1), respectively. The methanogenic activity of H(2)-utilizing methanogens was higher than acetate-utilizing methanogens, indicating that maintaining a low partial pressure of hydrogen does not inhibit the acetoclastic methanogenesis or the anaerobic process.

  10. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste.

    Science.gov (United States)

    Xu, Suyun; Selvam, Ammaiyappan; Wong, Jonathan W C

    2014-02-01

    Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35°C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21-27% and 38-64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH4/g VS(added) in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO2 respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.

  11. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become m

  12. Performance and characterization of a newly developed self-agitated anaerobic reactor with biological desulfurization.

    Science.gov (United States)

    Kobayashi, Takuro; Li, Yu-You

    2011-05-01

    The continuous operation of a newly developed methane fermentation reactor, which requires no electricity for the agitation of the fermentation liquid was investigated, and the extent of the biological desulfurization was monitored. Inside the reactor, the continual change in the liquid level and the self-agitation, occurring between 5 and 16 times every day, distributed the organic load near the inlet port of the reactor, as well as providing a nutrient supply to the hydrogen sulfide oxidizing bacteria. At different COD(Cr) loading rates (5, 7, 10 kg m(3)d(-1)), the reactor achieved a biogas production yield of 0.72-0.82 m(3)g(-1)-TS, a COD(Cr) reduction of 79.4-85.5% and an average of 99% hydrogen sulfide removal. This investigation demonstrated that the self-agitated reactor is comparable in digestion performance to the completely stirred tank reactor (CSTR) investigated in a previous study, and that the desulfurization performance was significantly enhanced compared to the CSTR.

  13. Effect of organic loading rate on methane and volatile fatty acids productions from anaerobic treatment of palm oil mill effluent in UASB and UFAF reactors

    Directory of Open Access Journals (Sweden)

    Sumate Chaiprapat

    2007-05-01

    Full Text Available Anaerobic treatment of palm oil mill effluent (POME with the separation of the acidogenic and methanogenic phase was studied in an up-flow anaerobic sludge blanket (UASB reactor and an up-flowanaerobic filter (UFAF reactor. Furthermore, the effect of OLR on methane and volatile fatty acid productions in UASB and UFAF reactors was investigated. In this research, UASB as acidogenic reactor wasused for volatile fatty acid production and UFAF as methanogenic reactor was used for methane production. Therefore, POME without pH adjustment was used as influent for the UASB reactor. Moreover, the syntheticwastewater with pH adjustment to 6.00 was fed into the UFAF reactor. The inoculum source for both reactors was the combination of POME sludge collected from the CSTR of a POME treatment plant and granulesludge collected from the UASB reactor of a frozen sea food industry treatment plant. During experimental operation, the organic loading rate (OLR was gradually increased from 2.50 to 17.5 g COD/l/day in theUASB reactor and 1.10 to 10.0 g COD/l/day in the UFAF reactor. Consequently, hydraulic retention time (HRT ranged from 20.0 to 2.90 days in the UASB reactor and from 13.5 to 1.50 days in the UFAF reactor.The result showed that the COD removal efficiency from both reactors was greater than 60.0%. In addition, the total volatile fatty acids increased with the increasing OLR. The total volatile fatty acids and acetic acidproduction in the UASB reactor reached 5.50 g/l and 4.90 g/l, respectively at OLR of 17.5 g COD/l/day and HRT of 2.90 days before washout was observed. In the UFAF reactor, the methane and biogas productionincreased with increasing OLR until an OLR of 7.50 g COD/l/day. However, the methane and biogas production significantly decreased when OLR increased up to 10.0 g COD/l/day. Therefore, the optimum OLR inthe laboratory-scale UASB and UFAF reactors were concluded to be 15.5 and 7.50 g COD/l/day, respectively.

  14. Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system

    Institute of Scientific and Technical Information of China (English)

    PENG Yongzhen; HOU Hongxun; WANG Shuying; CUI Youwei; Zhiguo Yuan

    2008-01-01

    To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal(SNDPR),a whole course of SNDPR damage and recovery was studied in a pilot-scale,anaerobicanoxic oxidation ditch(OD),where the volumes of anaerobic zone,anoxic zone,and ditches zone of the OD system were 7,21,and 280L,respectively.The reactor was fed with municipal wastewater with a flow rate of 336 L/d.The concept of simultaneous nitrification and denitrification (SND)rate(rSND) was put forward to quantify SND.The results indicate that:(1)high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase,total nitrogen (TN) and total phosphate(TP) removal rates were 80%and 85%,respectively;(2)when the system was aerated excessively,the stability of SND was damaged,and rSND dropped from 80% to 20%or less;(3)the natural logarithm of the ratio of NOx to MJ4+ in the effluent had a linear correlation to oxidation-reduction potential (ORP);(4)when NO3- was less than 6 mg/L.high phosphorus removal efficiency could be achieved;(5)denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system.The major innovation was that the SND rate was devised and quantified.

  15. Artificial intelligence based model for optimization of COD removal efficiency of an up-flow anaerobic sludge blanket reactor in the saline wastewater treatment.

    Science.gov (United States)

    Picos-Benítez, Alain R; López-Hincapié, Juan D; Chávez-Ramírez, Abraham U; Rodríguez-García, Adrián

    2017-03-01

    The complex non-linear behavior presented in the biological treatment of wastewater requires an accurate model to predict the system performance. This study evaluates the effectiveness of an artificial intelligence (AI) model, based on the combination of artificial neural networks (ANNs) and genetic algorithms (GAs), to find the optimum performance of an up-flow anaerobic sludge blanket reactor (UASB) for saline wastewater treatment. Chemical oxygen demand (COD) removal was predicted using conductivity, organic loading rate (OLR) and temperature as input variables. The ANN model was built from experimental data and performance was assessed through the maximum mean absolute percentage error (= 9.226%) computed from the measured and model predicted values of the COD. Accordingly, the ANN model was used as a fitness function in a GA to find the best operational condition. In the worst case scenario (low energy requirements, high OLR usage and high salinity) this model guaranteed COD removal efficiency values above 70%. This result is consistent and was validated experimentally, confirming that this ANN-GA model can be used as a tool to achieve the best performance of a UASB reactor with the minimum requirement of energy for saline wastewater treatment.

  16. Long-term stability of thermophilic co-digestion submerged anaerobic membrane reactor encountering high organic loading rate, persistent propionate and detectable hydrogen in biogas.

    Science.gov (United States)

    Qiao, Wei; Takayanagi, Kazuyuki; Niu, Qigui; Shofie, Mohammad; Li, Yu You

    2013-12-01

    The performance of thermophilic anaerobic co-digestion of coffee grounds and sludge using membrane reactor was investigated for 148 days, out of a total research duration of 263 days. The OLR was increased from 2.2 to 33.7 kg-COD/m(3)d and HRT was shortened from 70 to 7 days. A significant irreversible drop in pH confirmed the overload of reactor. Under a moderately high OLR of 23.6 kg-COD/m(3)d, and with HRT and influent total solids of 10 days and 150 g/L, respectively, the COD removal efficiency was 44.5%. Hydrogen in biogas was around 100-200 ppm, which resulted in the persistent propionate of 1.0-3.2g/L. The VFA consumed approximately 60% of the total alkalinity. NH4HCO3 was supplemented to maintain alkalinity. The stability of system relied on pH management under steady state. The 16SrDNA results showed that hydrogen-utilizing methanogens dominates the archaeal community. The propionate-oxidizing bacteria in bacterial community was insufficient.

  17. Hydrodynamic behavior of a combined anaerobic-aerobic system employed in the treatment of vinasse

    Directory of Open Access Journals (Sweden)

    Fátima Resende Luiz Fia

    Full Text Available ABSTRACT The understanding of reactor hydrodynamics is essential for improving the performance of a reactor and biogas production. This study sought to evaluate the hydrodynamic behavior of a combined anaerobic-aerobic system at a laboratory scale for treating vinasse. The experiment was conducted in a system using two UASB reactors connected in series, followed by an Aerated Submerged Biological Filter (ASBF. The flow rates applied to the system and the corresponded theoretical HRTs in the UASB1, UASB2 and ASBF were respectively: 15.6 L d-1 and 1.2 d, 1.2 d and 1.0 d (Phase I - first year; 8.5 L d-1 and 2.1 d; 2.1 d and 1.8 d (Phase II - first year, 14.6 L d-1 and 1.1 d, 1.1 d and 1.0 d (Phase III - second year; 29.5 L d-1 and 0.6 d, 0.6 d and 0.5 d (Phase IV - second year. The hydrodynamic studies were carried out using pulse type stimulus-response tests, employing LiCl as a tracer. The coefficients of determination for the dispersion models (R2 indicate a close approximation of a continuous stirred tank reactor in series (multi-CSTR model, with an average of 2.5, 2.3 and 1.2 (first year, and 1.1, 1.4 and 0.9 (second year multi-CSTR for UASB1, UASB2 and ASBF, respectively. Results of the hydrodynamic tests carried out in UASB1, UASB2 and ASBF indicated strong tendency for flow in the complete mixture hydraulic regime, detecting a wide dispersion in the units, in addition to the presence of short circuits and dead zones.

  18. Biological reactor for anaerobic digestion of organic materials to produce methane gas by fermentation by enzymes. Bioreaktor fuer anaerobe Ausfaulung organischer Stoffe zur Methangaserzeugung mittels Fermentierung durch Enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, R.W.

    1981-11-12

    In order to make undisturbed development of the methane bacteria possible, the biomass (organic waste of all kinds, e.g. sewage sludge, manure, organic industrial waste) is first pre-fermented by adding enzymes. The methane bacteria, which are used to inject the biomass in the fermentation reactor, are fermented separately in feeding solutions. The biological reactor is a system heated by a thermostatically controlled waterbath, with at least 12 individual digestion chambers, which are filled in sequence with biomass. Circulation and therefore destruction of the floating sludge layer is done with biogas produced under pressure in the system. By adding lime solution, a pH value of 7 is set in the chambers. The advantages of the invention consist of a shortened digestion time (6 days) and a reduced CO/sub 2/ consist at a gas yield of 80%.

  19. 废水厌氧处理反应器功能拓展研究进展%Multifunctional role of anaerobic reactors in wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    徐恒; 汪翠萍; 王凯军

    2014-01-01

    废水厌氧处理技术自从1860年左右开始得到快速发展,尤其是高效厌氧反应器的研发,使得其应用范围逐步由传统温和的环境和水质条件转向各种极端条件。然而,一般认为厌氧反应器的目标主要还停留在实现废水中有机污染物的甲烷化与高效去除层面,功能比较单一。在实际厌氧反应器中,其他污染物如氮、硫等同样得到不同程度的去除;此外,厌氧反应器的其他新型功能拓展研究也逐步受到关注。然而,目前这些研究大多数围绕着某一个特定研究点展开,相对独立,其研究现状和应用效果缺乏系统的汇总与梳理。该文一方面对厌氧处理技术的发展和厌氧反应器传统功能研究现状进行归纳;另一方面着重对其实现脱硫、脱氮、除磷、除钙软化以及原位沼气提纯等拓展功能的作用原理和过程特点进行综述,以达到系统解析厌氧反应器在废水处理中多重功能作用的目的。同时,该文在综述过程中发现目前多功能厌氧反应器在构型、运行参数、耦合模型构建与调控等方面的研究存在严重不足,难以保证反应器整体性能最优化。通过综述废水厌氧处理反应器功能拓展研究进展可能会对厌氧处理技术进一步发展以及新型多功能厌氧反应器研发有着一定的借鉴意义。%Since 1860, anaerobic technology has undergone rapid development, particularly with the invention of the high-rate anaerobic reactors, and has been widely applied in treating different types of wastewater under extreme environmental conditions. However, the major functional role of anaerobic reactors is generally considered to be removing organic pollutants via methanogenesis. In fact, the actual reactions involved in anaerobic reactors are extremely complex, which also have positive effects on removing inorganic pollutants (N, P, S, etc.). The performance of the removal of

  20. Biodegradation of Reactive blue 13 in a two-stage anaerobic/aerobic fluidized beds system with a Pseudomonas sp. isolate.

    Science.gov (United States)

    Lin, Jun; Zhang, Xingwang; Li, Zhongjian; Lei, Lecheng

    2010-01-01

    Pseudomonas sp. strain L1 capable of degrading the azo textile dye Reactive blue 13, was isolated from activated sludge in a sequencing batch reactor. A continuous two-stage anaerobic/aerobic biological fluidized bed system was used to decolorize and mineralize Reactive blue 13. The key factors affecting decolorization were investigated and the efficiency of degradation was also optimized. An overall color removal of 83.2% and COD removal of 90.7% was achieved at pH 7, a residence time of 70 h and a glucose concentration of 2 g/L, HRT=70 h and C(glucose)=2000 mg/L. Oxygen was contributing to blocking the azo bond cleavage. Consequently, decolorization occurred in the anaerobic reactor while partial mineralization was achieved in the aerobic reactor. A possible degradation pathway based on the analysis of intermediates and involving azoreduction, desulfonation, deamination and further oxidation reactions is presented.

  1. Tolerance response to in situ ammonia stress in a pilot-scale anaerobic digestion reactor for alleviating ammonia inhibition.

    Science.gov (United States)

    Gao, Shumei; Zhao, Mingxing; Chen, Yang; Yu, Meijuan; Ruan, Wenquan

    2015-12-01

    The anaerobic digestion (AD) of protein-rich substrates is generally inhibited by ammonia. In this study, ammonia-tolerant acclimation was exposed to a stepwise in situ ammonia stress during the continuous AD of solid residual kitchen waste by using a continuous stirred tank reactor with a 50 L active volume. The reactor worked well during the acclimation process, with an average daily biogas production of 58 L/d, an effluent soluble chemical oxygen demand of 7238 mg/L, a volatile fatty acid (VFA) content of 578 mg/L, and a VFA/alkalinity ratio of less than 0.4. Moreover, ammonia stress enhanced the activity of Coenzyme F420. The results of high-throughput 16S rDNA sequencing showed that ammonia stress increased the relative abundance of Firmicutes bacteria and hydrogenotrophic methanogens but decreased the abundance of acetotrophic methanogens. This microbial community shift was proposed to be an in situ response strategy for ammonia stress adaptation.

  2. Anaerobic co-digestion of vegetable waste and swine wastewater in high-rate horizontal reactors with fixed bed.

    Science.gov (United States)

    Mazareli, Raissa Cristina da Silva; Duda, Rose Maria; Leite, Valderi Duarte; Oliveira, Roberto Alves de

    2016-06-01

    Considering the high waste generation that comes from agriculture and livestock farming, as well as the demand for natural gas, it is necessary to develop sustainable technologies which can reduce environmental impact. There is no available literature on the use of high-rate horizontal anaerobic reactors with fixed bed (HARFB) and continuous feed for the co-digestion of vegetable wastes (VW) and swine wastewater (SW). The aim of this work was to evaluate the reactor performance in terms of methane production, organic matter consumption, and removal of total and thermotolerant coliforms under different proportions of SW and VW, and organic loading rates (OLR) of 4.0, 5.2 and 11.0g COD (Ld)(-)(1). The mixture of SW and VW in the proportions of 90:10, 80:20 and 70:30 (SW:VW) with those OLRs provided great buffering capacity, with partial alkalinity reaching 3552mgL(-1), thereby avoiding the inhibition of methane production by volatile fatty acids produced during the fermentation process. Higher proportions of VW and higher OLR improved volumetric methane production with a maximum value of 1.08LCH4 (Ld)(-)(1), organic matter removal rates up to 98% and total and thermotolerant coliform removal rates of 99% were also observed.

  3. Treatment of anaerobic digester effluents of nylon wastewater through chemical precipitation and a sequencing batch reactor process.

    Science.gov (United States)

    Huang, Haiming; Song, Qianwu; Wang, Wenjun; Wu, Shaowei; Dai, Jiankun

    2012-06-30

    Chemical precipitation, in combination with a sequencing batch reactor (SBR) process, was employed to remove pollutants from anaerobic digester effluents of nylon wastewater. The effects of the chemicals along with various Mg:N:P ratios on the chemical precipitation (struvite precipitation) were investigated. When brucite and H(3)PO(4) were applied at an Mg:N:P molar ratio of 3:1:1, an ammonia-removal rate of 81% was achieved, which was slightly more than that (80%) obtained with MgSO(4)·7H(2)O and Na(2)HPO(4)·12H(2)O at Mg:N:P molar ratios greater than the stoichiometric ratio. To further reduce the ammonia loads of the successive biotreatment, an overdose of phosphate with brucite and H(3)PO(4) was applied during chemical precipitation. The ammonia-removal rate at the Mg:N:P molar ratio of 3.5:1:1.05 reached 88%, with a residual PO(4)-P concentration of 16 mg/L. The economic analysis showed that the chemical cost of chemical precipitation could be reduced by about 41% when brucite and H(3)PO(4) were used instead of MgSO(4)·7H(2)O and Na(2)HPO(4)·12H(2)O. The subsequent biological process that used a sequencing batch reactor showed high removal rates of contaminants. The quality of the final effluent met the requisite effluent-discharging standards.

  4. Trichloroethylene removal and bacterial variations in the up-flow anaerobic sludge blanket reactor in response to temperature shifts.

    Science.gov (United States)

    Zhang, Ying; Hu, Miao; Li, Pengfei; Wang, Xin; Meng, Qingjuan

    2015-07-01

    Trichloroethylene (TCE) degradation and the variations of bacteria composition and structure in the up-flow anaerobic sludge blanket (UASB) reactor were investigated by increasing the operating temperature from 20 to 40 °C. The influent was supplemented with 36.5 mg/L of TCE. There was a rise in the chemical oxygen demand (COD) removal efficiency from 20 to 35 °C and a decline when temperature enhanced to 40 °C. It reached maximum at 35 °C. In addition, TCE removal efficiency increased with temperature varying from 20 to 35 °C, and it dropped dramatically to 78.38 % at 40 °C, which presumably because the genus of Dehalobacter, a kind of bacteria with the ability to dechlorinate TCE to the corresponding chlorinated products, was not detected at 40 °C according to sequencing results. The Illumina MiSeq platform was adopted to explore the bacteria composition and structure in response to temperature shifts. The results indicated that temperature impacted greatly on the dominance and presence of specific populations at different taxonomic levels. Importantly, the class Dehalococcoidia was detected from 25 to 40 °C, in which there were many well-known Dehalococcoides sp. strains that were capable of complete dechlorination of TCE to ethene. It also suggested the potential function of the dominant genera (non-dechlorinating bacteria and dechlorinating bacteria) in the reactor.

  5. The biorotor system for posttreatment of anaerobically treated domestic sewage

    NARCIS (Netherlands)

    Tawfik, A.I.

    2002-01-01

    This thesis describes the evaluation of the applicability of biorotor system for post-treatment (polishing) of different effluent qualities of an UASB reactor treating raw domestic sewage, with emphasis on the elimination of various COD fractions, ammonia and E.Coli.The removal mechanism of E.Coli f

  6. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    tolerant methanogenic culture as potential bioaugmentation inoculum in a continuous stirred tank reactor (CSTR) operating under “inhibited steady-state”, triggered by high ammonia levels (5 g NH4+-N L-1). The results of the current study established for the first time that bioaugmentation of an enriched...... ammonia tolerant methanogen in a CSTR reactor could completely alleviate the ammonia inhibitory effect. Furthermore, it was found that bioaugmentation with the enriched culture resulted in 25% higher methane production compared to when the bioaugmentation was achieved with pure methanogenic strains....... The bioaugmentation was performed without pausing the continuous operation of the CSTR reactor and without excluding the ammonia-rich substrate from the feedstock. Thus, bioaugmentation with mixed methanogenic cultures could potentially support the development of an efficient and cost-effective biomethanation process...

  7. Gaseous fuel reactor systems for aerospace applications

    Science.gov (United States)

    Thom, K.; Schwenk, F. C.

    1977-01-01

    Research on the gaseous fuel nuclear rocket concept continues under the programs of the U.S. National Aeronautics and Space Administration (NASA) Office for Aeronautics and Space Technology and now includes work related to power applications in space and on earth. In a cavity reactor test series, initial experiments confirmed the low critical mass determined from reactor physics calculations. Recent work with flowing UF6 fuel indicates stable operation at increased power levels. Preliminary design and experimental verification of test hardware for high-temperature experiments have been accomplished. Research on energy extraction from fissioning gases has resulted in lasers energized by fission fragments. Combined experimental results and studies indicate that gaseous-fuel reactor systems have significant potential for providing nuclear fission power in space and on earth.

  8. Reactor control rod timing system. [LMFBR

    Science.gov (United States)

    Wu, P.T.K.

    1980-03-18

    A fluid driven jet-edge whistle timing system is described for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

  9. Performance evaluation of a completely stirred anaerobic reactor treating pig manure at a low range of mesophilic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jianbin, E-mail: jianbinguo@gmail.com [Department of Environmental Engineering, Tsinghua University, Beijing 100084 (China); Dong, Renjie [College of Engineering, China Agricultural University, P.O. Box 184, Beijing 100083 (China); Clemens, Joachim [Institute of Crop Science and Resource Reservation (INRES), University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115 Bonn (Germany); Wang, Wei [Department of Environmental Engineering, Tsinghua University, Beijing 100084 (China)

    2013-11-15

    Highlights: • The biogas process can run stably at 20 °C at extremely low OLR after long-term acclimation of bacteria. • A biogas plant running at 28 °C seems as efficient as that operated at 38 °C at low OLR of 1.3 g ODM L{sup −1} d{sup −1}. • Lower temperature operation is inadvisable for the commercial biogas plant running at rather high OLR. • The estimated sludge yield at 28 °C is higher than that at 38 °C. - Abstract: Many Chinese biogas plants run in the lower range of mesophilic conditions. This study evaluated the performance of a completely stirred anaerobic reactor treating pig manure at different temperatures (20, 28 and 38 °C). The start-up phase of the reactor at 20 °C was very long and extremely poor performance was observed with increasing organic loading rate (OLR). At an OLR of 4.3 g ODM L{sup −1} d{sup −1}, methane production at 28 °C was comparable (3% less) with that at 38 °C, but the risk of acidification was high at 28 °C. At low OLR (1.3 g ODM L{sup −1} d{sup −1}), the biogas process appeared stable at 28 °C and gave same methane yields as compared to the reactor operating at 38 °C. The estimated sludge yield at 28 °C was 0.065 g VSS g{sup −1} COD{sub removed,} which was higher than that at 38 °C (0.016 g VSS g{sup −1} COD{sub removed})

  10. The performance enhancements of upflow anaerobic sludge blanket (UASB) reactors for domestic sludge treatment--a state-of-the-art review.

    Science.gov (United States)

    Chong, Siewhui; Sen, Tushar Kanti; Kayaalp, Ahmet; Ang, Ha Ming

    2012-07-01

    Nowadays, carbon emission and therefore carbon footprint of water utilities is an important issue. In this respect, we should consider the opportunities to reduce carbon footprint for small and large wastewater treatment plants. The use of anaerobic rather than aerobic treatment processes would achieve this aim because no aeration is required and the generation of methane can be used within the plant. High-rate anaerobic digesters receive great interests due to their high loading capacity and low sludge production. Among them, the upflow anaerobic sludge blanket (UASB) reactors have been most widely used. However, there are still unresolved issues inhibiting the widespread of this technology in developing countries or countries with climate temperature fluctuations (such as subtropical regions). A large number of studies have been carried out in order to enhance the performance of UASB reactors but there is a lack of updated documentation. In face of the existing limitations and the increasing importance of this technology, the authors present an up-to-date review on the performance enhancements of UASB reactors over the last decade. The important aspects of this article are: (i) enhancing the start-up and granulation in UASB reactors, (ii) coupling with post-treatment unit to overcome the temperature constraint, and (iii) improving the removal efficiencies of the organic matter, nutrients and pathogens in the final effluent. Finally the authors have highlighted future research direction based on their critical analysis.

  11. Strategies for recovering inhibition caused by long chain fatty acids on anaerobic thermophilic biogas reactors

    DEFF Research Database (Denmark)

    Palatsi, J.; Laureni, M.; Andres, M.V.

    2009-01-01

    Long chain fatty acids (LCFA) concentrations over 1.0 g L1 were inhibiting manure thermophilic digestion, in batch and semi-continuous experiments, resulting in a temporary cease of the biogas production. The aim of the work was to test and evaluate several recovery actions, such as reactor feedi...

  12. Innovative self-powered submersible microbial electrolysis cell (SMEC) for biohydrogen production from anaerobic reactors

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2012-01-01

    . Furthermore, 16S rRNA genes analysis showed that this special operation strategy resulted same microbial community structures in the anodic biofilms of the two cell units. The simple, compact and in situ applicable SMEC offers new opportunities for reactor design for a microbial electricity...

  13. Tratamiento de las excretas de cerdo mediante un reactor anaeróbico SCFBR a nivel de banco Treatment of pig excreta using an SCFBR anaerobic reactor

    Directory of Open Access Journals (Sweden)

    Caicedo Luis A.

    1999-06-01

    Full Text Available Un nuevo reactor anaeróbico denominado Sludge Central Fixed Bed Reactor (SCFBR fue construido y evaluado para tratar los residuos líquidos de las granjas porcícolas. El SCFBR está constituido por tres zonas principales. Una zona inferior de lodos, seguida por un módulo empacado ubicado en forma concéntrica y, en la parte superior, una zona de separación sólido, líquido y gas. El reactor de 28,5 1 de volumen de reacción fue evaluado durante 210 días para tres cargas orgánicas de 0,548, 0,421 y 1,239 g DQO/ 1 día. El SCFBR fue alimentado inicialmente en forma discontinua con tiempos de retención hidráulicos (TRH de 10 y 10,7 días. Posteriormente el TRH fue disminuido a 3,87 días con una alimentación en continuo. Para las tres cargas orgánicas de 0,548, 0,421 y 1,239 g DQO/1 día se obtuvieron remociones en la demanda química de oxígeno (DQO de 68%, 81% y 73% y en los sólidos volátiles (SV, de 53,5%, 55,8% y 50,1%, respectivamente. El SCFBR presentó un buen desempeño, re-presentado en las eficiencias de remoción y en la estabilidad observada. Se presenta una microfotografía tomada de una muestra de lodo de la zona inferior del SCFBR, observándose una gran presencia de microorganismos del género Methanosaeta (Methanothrix.

    A new anaerobic reactor called the Sludge Central Fixed Bed Reactor (SCFBR was built and evaluated for the treatment of liquid residue from the pig farms. The SCFBR has three main parts. The lower area is for sludge, the middle part consists of a concentrically

  14. Polyurethane rotating disc system for post-treatment of anaerobically pre-treated sewage

    NARCIS (Netherlands)

    Tawfik, A.; Klapwijk, A.

    2010-01-01

    The performance of polyurethane rotating discs (RBC-1) versus polystyrene rotating discs (RBC-2) for the treatment of an up-flow anaerobic sludge blanket (UASB) reactor effluent fed with domestic wastewater was investigated. Both RBC units were operated at the same organic loading rate (OLR) of 10.5

  15. Evaluating a model of anaerobic digestion of organic wastes through system identification

    Energy Technology Data Exchange (ETDEWEB)

    Anex, R.P.; Kiely, G.

    1999-07-01

    Anaerobic digestion of the organic fraction of municipal solid waste (MSW), on its own or co-digested with primary sewage sludge (PSS), produces high quality biogas, suitable as renewable energy. Parameter estimation and evaluation of a two-stage mathematical model of the anaerobic co-digestion of the organic fraction of MSW and PSS are described. Measured data are from a bench scale laboratory experiment using a continuously stirred tank reactor and operated at 36 C for 115 days. The two-stage model simulates acidogenesis and methanogenesis, including ammonia inhibition. Model parameters are estimated using an output error, Levenberg-Marquardt (LM) algorithm. Sensitivity of the estimated parameter values and the model outputs to non-estimated model parameters and measurement errors are evaluated. The estimated mathematical model successfully predicts the performance of the anaerobic reactor. Sensitivity results provide guidance for improving the model structure and experimental procedures.

  16. Thermophilic sulfate reduction and methanogenesis with methanol in a high rate anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Weijma, J.; Stams, A.J.M.; Pol, L.W.H.; Lettinga, G.

    2000-02-05

    Sulfate reduction outcompeted methanogenesis at 65 C and pH 7.5 in methanol and sulfate-fed expanded granular sludge bed reactors operated at hydraulic retention times (HRT) of 14 and 2.5 h, both under methanol-limiting and methanol-overloading conditions. After 100 and 50 days for the reactors operated at 14 and 3.5 h, respectively, sulfide production accounted for 80% of the methanol-COD consumed by the sludge. The specific methanogenic activity on methanol of the sludge from a reactor operated at HRTs of down to 3.5 h for a period of 4 months gradually decreased from 0.83 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} at the start to a value of less than 0.05 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1}, showing that the relative number of methanogens decreased and eventually became very low. By contrast, the increase of the specific sulfidogenic activity of sludge from 0.22 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} to a final value of 1.05 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} showed that sulfate reducing bacteria were enriched. Methanol degradation by a methanogenic culture obtained from a reactor by serial dilution of the sludge was inhibited in the presence of vancomycin, indicating that methanogenesis directly from methanogenic culture obtained from a reactor by serial dilution of the sludge was inhibited in the presence of vancomycin, indicating that methanogenesis directly from methanol was not important. H{sub 2}/CO{sub 2} and formate, but not acetate, were degraded to methane in the presence of vancomycin. These results indicated that methanol degradation to methane occurs via the intermediates H{sub 2}/CO{sub 2} and formate. The high and low specific methanogenic activity of sludge on H{sub 2}/CO{sub 2} and formate, respectively, indicated that the former substrate probably acts as the main electron donor for the methanogens during methanol degradation. As

  17. Anaerobic digestion of blackwater from vacuum toilets and kitchen refuse in a continuous stirred tank reactor (CSTR).

    Science.gov (United States)

    Wendland, C; Deegener, S; Behrendt, J; Toshev, P; Otterpohl, R

    2007-01-01

    The objective of this research was mesophilic anaerobic digestion of blackwater from vacuum toilets (BW) and kitchen refuse (KR) in a CSTR within an ecological sanitation system. A detailed investigation of the BW characteristics was carried out. Research on anaerobic digestion was performed with CSTR of 101 volume at HRT of 10, 15 and 20 days. The digestion of BW at 20 days HRT showed stable performance without inhibition effects, in spite of relatively high ammonium concentrations. The removal of total and particulate COD was 61% and 53%, respectively, and the methane yield 10/CH4/cap/day. The addition of kitchen refuse (KR) improved the performance of the CSTR in terms of COD removal efficiency and methane yield. At 20 days HRT the removal of total and particulate COD increased up to 71% and 67%, respectively, and the methane yield to 27/CH4/cap/day. The results at 15 days HRT showed similar performance. At HRT of 10 days, the anaerobic treatment was limited but reached steady state conditions at higher VFA concentrations in the effluent, with a decrease of COD removal of 30 to 33% and of methane yields of 19 to 21%.

  18. Integral reactor system and method for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Neil Edward; Brown, Michael S.; Cheekatamaria, Praveen; Deng, Thomas; Dimitrakopoulos, James; Litka, Anthony F.

    2017-03-07

    A reactor system is integrated internally within an anode-side cavity of a fuel cell. The reactor system is configured to convert higher hydrocarbons to smaller species while mitigating the lower production of solid carbon. The reactor system may incorporate one or more of a pre-reforming section, an anode exhaust gas recirculation device, and a reforming section.

  19. Integral reactor system and method for fuel cells

    Science.gov (United States)

    Fernandes, Neil Edward; Brown, Michael S; Cheekatamarla, Praveen; Deng, Thomas; Dimitrakopoulos, James; Litka, Anthony F

    2013-11-19

    A reactor system is integrated internally within an anode-side cavity of a fuel cell. The reactor system is configured to convert hydrocarbons to smaller species while mitigating the lower production of solid carbon. The reactor system may incorporate one or more of a pre-reforming section, an anode exhaust gas recirculation device, and a reforming section.

  20. High-rate anaerobic hydrolysis and acidogenesis of sewage sludge in a modified upflow reactor.

    Science.gov (United States)

    Yu, H Q; Zheng, X J; Hu, Z H; Gu, G W

    2003-01-01

    Continuous experiments were conducted to study the hydrolysis and acidogenesis of sewage sludge in an upflow reactor with an agitator and a gas-liquid-solid separator. Results of this study showed that 34-78% of volatile suspended solids (VSS) in sewage sludge was hydrolyzed at pH in the range 4.0-6.5, 35 degrees C and 4-24 hours of hydraulic retention time (HRT). About 31-65% of carbohydrate in sewage sludge, 20-45% of protein and 14-24% of lipid were acidified in this reactor. Hydrogen production was favored in lower pH and HRT, whereas methane production was encouraged at higher pH and HRT. Acetate, propionate, butyrate, and i-butyrate were the main aqueous acidogenic products. The distribution of these compounds in the effluent was more sensitive to pH, but was less sensitive to HRT. The maximu specific COD solubilization rate and specific volatile fatty acids production rate were 126 mg-COD/g-VSS x d and 102 mg-VFAIg-VSS x d, respectively. Compared with a CSTR, this modified upflow reactor was shown to be a more promising biosystem for the hydrolysis and acidogenesis of sewage sludge.

  1. High-calorific biogas production from anaerobic digestion of food waste using a two-phase pressurized biofilm (TPPB) system.

    Science.gov (United States)

    Li, Yeqing; Liu, Hong; Yan, Fang; Su, Dongfang; Wang, Yafei; Zhou, Hongjun

    2017-01-01

    To obtain high calorific biogas via anaerobic digestion without additional upgrading equipment, a two-phase pressurized biofilm system was built up, including a conventional continuously stirred tank reactor and a pressurized biofilm anaerobic reactor (PBAR). Four different pressure levels (0.3, 0.6, 1.0 and 1.7MPa) were applied to the PBAR in sequence, with the organic loading rate maintained at 3.1g-COD/L/d. Biogas production, gas composition, process stability parameters were measured. Results showed that with the pressure increasing from 0.3MPa to 1.7MPa, the pH value decreased from 7.22±0.19 to 6.98±0.05, the COD removal decreased from 93.0±0.9% to 79.7±1.2% and the methane content increased from 80.5±1.5% to 90.8±0.8%. Biogas with higher calorific value of 36.2MJ/m(3) was obtained at a pressure of 1.7MPa. Pressure showed a significant effect on biogas production and gas quality in methanogenesis reactor.

  2. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suyun [Department of Environmental and Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai (China); Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong); Selvam, Ammaiyappan [Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong); Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk [Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong)

    2014-02-15

    Highlights: • Effect of micro-aeration on acidogenesis and hydrolysis of food waste was investigated. • Micro-aeration at 258 L-air/kg TS/d increased the VFAs production 3-fold. • High aeration leads to loss of substrate through microbial biomass and respiration. • Optimum aeration increased methane recovery while high aeration intensity reduced methane yield. - Abstract: Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH{sub 4}/g VS{sub added} in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO{sub 2} respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.

  3. Effects of cycle-frequency and temperature on the performance of anaerobic sequencing batch reactors (ASBRs) treating swine waste.

    Science.gov (United States)

    Ndegwa, P M; Hamilton, D W; Lalman, J A; Cumba, H J

    2008-04-01

    Anaerobic digestion of animal waste is a technically viable process for the abatement of adverse environmental impacts caused by animal wastes; however, widespread acceptance has been plagued by poor economics. This situation is dismal if the technology is adapted for treating low strength animal slurries because of large digester-volume requirements and a corresponding high energy input. A possible technology to address these constraints is the anaerobic sequencing batch reactor (ASBR). The ASBR technology has demonstrated remarkable potential to improve the economics of treating dilute animal waste effluents. This paper presents preliminary data on the effects of temperature and frequency-cycle on the operation of an ASBR at a fixed hydraulic retention time (HRT). The results suggest that within the parameter range under consideration, temperature did not affect the biogas yield significantly, however, higher cycle-frequency had a negative effect. The biogas quality (%CH(4)) was not significantly affected by temperature nor by the cycle-frequency. The operating principle of the ASBR follows four phases: feed, react, settle, and decant in a cyclic mode. To improve the biogas production in an ASBR, one long react-phase was preferable compared to three shorter react-phases. Treatment of dilute manure slurries in an ASBR at 20 degrees C was more effective than at 35 degrees C; similarly more bio-stable effluents were obtained at low cycle-frequency. The treatment of dilute swine slurries in an ASBR at the lower temperature (20 degrees C) and lower cycle-frequency is, therefore, recommended for the bio-stabilization of dilute swine wastewaters. The results also indicate that significantly higher VFA degradation occurred at 20 degrees C than at 35 degrees C, suggesting that the treatment of dilute swine slurries in ASBRs for odor control might be more favorable at the lower than at the higher temperatures examined in this study. Volatile fatty acid reduction at the two

  4. ABR处理大豆蛋白废水产氢效能的研究%Performance of hydrogen production in anaerobic baffled reactor (ABR) treating soy protein wastewater

    Institute of Scientific and Technical Information of China (English)

    王帅; 李博; 赵倩; 姜力行; 曹莉; 李永峰

    2011-01-01

    Anaerobic Baffled Reactor (ABR) is a class derived from multi-phase anaerobic reactor stages (Staged Multi -Phase Anaerobic Reactor, SMPA) theory of the third generation of a new anaerobic reactor. To study of anaerobic baffled reactor (ABR) soy protein wastewater treatment efficiency and operating characteristics of the 4 cell room operation of the system of ABR control measures were studied using the effective volume of 42 L four -room frame ABR, MLVSS in the sludge inoculum for the 18.0 g/ L, influent COD concentration of 2 000 mg/L , HRT 48 h, (35 ± 1) ℃ and other conditions (ie OLR1. 0 kg/( m3 · d) ) , running through a period of 80 d of the study based on the influent COD concentration was increased organic load ( OLR) to change the impact of its processing power, can successfully started in 31 d and reached the initial ABR and stable operation. In addition, rate of 96% , studied different organic load, ABR reactor COD removal efficiency and gas production. On this basis, for the efficient development of ABR equipment, and successfully applied to fermentation technology and bio-hydrogen production of soy protein wastewater treatment under study was provided.%厌氧折流板反应器(ABR)是一类源于分阶段多相厌氧反应器(Staged Multi -Phase Anaerobic Reactor,SMPA)理论的第三代新型厌氧反应器.为考察厌氧折流板反应器(ABR)处理大豆蛋白生产废水的效能及其运行特征,对4格室ABR反应系统的运行控制对策进行了研究,采用有效容积为42L的四格室ABR,在污泥接种量MLVSS为18.0 g/L、进水COD质量浓度2 000 mg/L、HRT 48 h、(35±1)℃等条件下(即OLR 1.0 kg/(m3·d)),通过为期80 d的运行,研究了基于进水COD质量浓度提高的有机负荷(OLR)改变对其处理效能的影响,可在31 d内成功启动ABR并达到初步稳定运行,研究不同有机负荷下,ABR反应器的COD去除效率及产气量.为在此基础上研发高效的ABR反应设备,并成功将其应用到发

  5. Advanced anaerobic bioconversion of lignocellulosic waste for the melissa life support system

    Science.gov (United States)

    Lissens, G.; Verstraete, W.; Albrecht, T.; Brunner, G.; Creuly, C.; Dussap, G.; Kube, J.; Maerkl, H.; Lasseur, C.

    The feasibility of nearly-complete conversion of lignocellulosic waste (70% food crops, 20% faecal matter and 10% green algae) into biogas was investigated in the context of the MELiSSA loop (Micro-Ecological Life Support System Alternative). The treatment comprised a series of processes, i.e. a mesophilic laboratory scale CSTR (continuously stirred tank reactor), an upflow biofilm reactor, a fiber liquefaction reactor employing the rumen bacterium Fibrobacter succinogenes and a hydrothermolysis system in near-critical water. By the one-stage CSTR, a biogas yield of 75% with a specific biogas production of 0.37 l biogas g-1 VSS (volatile suspended solids) added at a RT (hydraulic retention time) of 20-25 d was obtained. Biogas yields could not be increased considerably at higher RT, indicating the depletion of readily available substrate after 25 d. The solids present in the CSTR-effluent were subsequently treated in two ways. Hydrothermal treatment (T ˜ 310-350C, p ˜ 240 bar) resulted in effective carbon liquefaction (50-60% without and 83% with carbon dioxide saturation) and complete sanitation of the residue. Application of the cellulolytic Fibrobacter succinogenes converted remaining cellulose contained in the CSTR-effluent into acetate and propionate mainly. Subsequent anaerobic digestion of the hydrothermolysis and the Fibrobacter hydrolysates allowed conversion of 48-60% and 30%, respectively. Thus, the total process yielded biogas corresponding with conversions up to 90% of the original organic matter. It appears that particularly mesophilic digestion in conjunction with hydrothermolysis offers interesting features for (nearly) the MELiSSA system. The described additional technologies show that complete and hygienic carbon and energy recovery from human waste within MELiSSA is technically feasible, provided that the extra energy needed for the thermal treatment is guaranteed.

  6. Microchannel Reactor System for Catalytic Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Adeniyi Lawal; Woo Lee; Ron Besser; Donald Kientzler; Luke Achenie

    2010-12-22

    We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 – 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.

  7. Passive compact molten salt reactor (PCMSR), modular thermal breeder reactor with totally passive safety system

    Energy Technology Data Exchange (ETDEWEB)

    Harto, Andang Widi [Engineering Physics Department, Faculty of Engineering, Gadjah Mada University (Indonesia)

    2012-06-06

    Design Study Passive Compact Molten Salt Reactor (PCMSR) with totally passive safety system has been performed. The term of Compact in the PCMSR name means that the reactor system is designed to have relatively small volume per unit power output by using modular and integral concept. In term of modular, the reactor system consists of three modules, i.e. reactor module, turbine module and fuel management module. The reactor module is an integral design that consists of reactor, primary and intermediate heat exchangers and passive post shutdown cooling system. The turbine module is an integral design of a multi heating, multi cooling, regenerative gas turbine. The fuel management module consists of all equipments related to fuel preparation, fuel reprocessing and radioactive handling. The preliminary calculations show that the PCMSR has negative temperature and void reactivity coefficient, passive shutdown characteristic related to fuel pump failure and possibility of using natural circulation for post shutdown cooling system.

  8. Effects of feeding time and organic loading in an anaerobic sequencing batch biofilm reactor (ASBBR) treating diluted whey.

    Science.gov (United States)

    Damasceno, Leonardo H S; Rodrigues, José A D; Ratusznei, Suzana M; Zaiat, Marcelo; Foresti, Eugênio

    2007-12-01

    An investigation was carried out on the performance of an anaerobic sequencing batch biofilm reactor (ASBBR) treating diluted cheese whey when submitted to different feed strategies and volumetric organic loads (VOL). Polyurethane foam cubes were used as support for biomass immobilization and stirring was provided by helix impellers. The reactor with a working volume of 3 L treated 2 L of wastewater in 8-h cycles at 500 rpm and 30 degrees C. The organic loads applied were 2, 4, 8 and 12 g COD L(-1) d(-1), obtained by increasing the feed concentration. Alkalinity was supplemented at a ratio of 50% NaHCO(3)/COD. For each organic load applied three feed strategies were tested: (a) batch operation with 8-h cycle; (b) 2-h fed-batch operation followed by 6-h batch; and (c) 4-h fed-batch followed by 4-h batch. The 2-h fed-batch operation followed by 6-h batch presented the best results for the organic loads of 2 and 4 g COD L(-1) d(-1), whereas the 4-h fed-batch operation followed by 4-h batch presented results slightly inferior for the same organic loads and the best results at organic loads of 8 and 12 g COD L(-1) d(-1). The concentration of total volatile acids varied with fill time. For the higher fill times maximum concentrations were obtained at the end of the cycle. Moreover, no significant difference was detected in the maximum concentration of total volatile acids for any of the investigated conditions. However, the maximum values of propionic acid tended to decrease with increasing fill time considering the same organic load. Microbiological analyses revealed the presence of Methanosaeta-like structures and methanogenic hydrogenotrophic-like fluorescent bacilli. No Methanosarcina-like structures were observed in the samples.

  9. Staged membrane oxidation reactor system

    Science.gov (United States)

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2013-04-16

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  10. Anaerobic digestion technology in livestock manure treatment for biogas production: a review

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, Ismail M. [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, Selangor (Malaysia); Mohd Ghazi, Tinia I.; Omar, Rozita

    2012-06-15

    This article reviews the potential of anaerobic digestion (AD) for biogas production from livestock manure wastes and compares the operating and performance data for various anaerobic process configurations. It examines different kinds of manure waste treatment techniques and the influence of several parameters on biogas and methane yield. The comparison indicates that a variety of different operational conditions, various reactor configurations such as batch reactors, continuously stirred tank reactor (CSTR), plug flow reactor (PFR), up-flow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), temperature phased anaerobic digestion (TPAD), and continuous one- and two-stage systems, present a suitable technology for the AD of livestock manure waste. Main performance indicators are biogas and methane yield, degradation of volatile solids (VS), higher loading, and process stability with a short retention time. (copyright 2012 WILEY-VCH Verlag GmbH 8 Co. KGaA, Weinheim)

  11. Decolourization of anaerobically digested and polyaluminium chloride treated distillery spentwash in a fungal stirred tank aerobic reactor.

    Science.gov (United States)

    Singh, S S; Dikshit, A K

    2011-11-01

    Decolourization of anaerobically digested and polyaluminium chloride treated distillery spentwash was studied in a fungal stirred tank aerobic reactor without dilution of wastewater. Aspergillus niger isolate IITB-V8 was used as the fungal inoculum. The main objectives of the study were to optimize the stirrer speed for achieving maximum decolourization and to determine the kinetic parameters. A mathematical model was developed to describe the batch culture kinetics. Volumetric oxygen transfer coefficient (k (L) a) was obtained using dynamic method. The maximum specific growth rate and growth yield of fungus were determined using Logistic equation and using Luedeking-Piret equation. 150 rpm was found to be optimum stirrer speed for overall decolourization of 87%. At the optimum stirrer speed, volumetric oxygen transfer coefficient (k (L) a) was 0.4957 min(-1) and the maximum specific growth rate of fungus was 0.224 h(-1). The values of yield coefficient (Y ( x/s)) and maintenance coefficient (m (s)) were found to be 0.48 g cells (g substrate)(-1) and 0.015 g substrate (g cells)(-1) h(-1).

  12. Microbial diversity analysis of long term operated biofilm configured anaerobic reactor producing biohydrogen from wastewater under diverse conditions

    Energy Technology Data Exchange (ETDEWEB)

    Venkata Mohan, S.; Raghavulu, S. Veer; Goud, R. Kannaiah; Srikanth, S.; Babu, V. Lalit; Sarma, P.N. [Bioengineering and Environmental Centre (BEEC), Indian Institute of Chemical Technology (IICT), Hyderabad 500 607 (India)

    2010-11-15

    This communication provides an insight into the composition of the microbial community survived in the biofilm configured anaerobic reactor operated for biohydrogen (H{sub 2}) production using wastewater as substrate under diverse conditions for past four years. PCR amplified 16S rDNA product (at variable V3 region using universal primers 341F and 517R) was separated by using denaturing gradient gel electrophoresis (DGGE) to identify the diversity in microbial population survived. The phyologenetic profile of the bioreactor showed significant diversity in the microbial community where major nucleotide sequences were affiliated to Class Clostridia followed by Bacteroidetes, Deltaproteobacteria and Flavobacteria. Clostridium were found to be dominant in the microbial community observed. The controlled growth conditions, application of pre-treatment to biocatalyst, operation with specific pH and variation in substrate composition are reasoned for the robust acidogenic culture identified in the bioreactor. Most of the operational taxonomic units (OTUs) observed in the bioreactor are capable to undergo acetate producing pathway, feasible for effective H{sub 2} production. (author)

  13. Impact of organic loading rate on biohydrogen production in an up-flow anaerobic packed bed reactor (UAnPBR).

    Science.gov (United States)

    Ferraz, Antônio Djalma Nunes; Zaiat, Marcelo; Gupta, Medhavi; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George

    2014-07-01

    This study assesses the impact of organic loading rate on biohydrogen production from glucose in an up-flow anaerobic packed bed reactor (UAnPBR). Two mesophilic UAPBRs (UAnPBR1 and 2) were tested at organic loading rates (OLRs) ranging from 6.5 to 51.4 g COD L(-1)d(-1). To overcome biomass washout, design modifications were made in the UAnPBR2 to include a settling zone to capture the detached biomass. The design modifications in UAnPBR2 increased the average hydrogen yield from 0.98 to 2.0 mol-H2 mol(-1)-glucose at an OLR of 25.7 g COD L(-1)d(-1). Although, a maximum hydrogen production rate of 23.4 ± 0.9 L H2 L(-1)d(-1) was achieved in the UAnPBR2 at an OLR of 51.4 g COD L(-1)d(-1), the hydrogen yield dropped by 50% to around 1 mol-H2 mol(-1)-glucose. The microbiological analysis (PCR/DGGE) showed that the biohydrogen production was due to the presence of the hydrogen and volatile acid producers such as Clostridium beijerinckii, Clostridium butyricum, Megasphaera elsdenii and Propionispira arboris.

  14. Performance, kinetic, and biodegradation pathway evaluation of anaerobic fixed film fixed bed reactor in removing phthalic acid esters from wastewater

    Science.gov (United States)

    Ahmadi, Ehsan; Yousefzadeh, Samira; Ansari, Mohsen; Ghaffari, Hamid Reza; Azari, Ali; Miri, Mohammad; Mesdaghinia, Alireza; Nabizadeh, Ramin; Kakavandi, Babak; Ahmadi, Peyman; Badi, Mojtaba Yegane; Gholami, Mitra; Sharafi, Kiomars; Karimaei, Mostafa; Ghoochani, Mahboobeh; Brahmand, Masoud Binesh; Mohseni, Seyed Mohsen; Sarkhosh, Maryam; Rezaei, Soheila; Asgharnia, Hosseinali; Dehghanifard, Emad; Jafari, Behdad; Mortezapour, Alireza; Moghaddam, Vahid Kazemi; Mahmoudi, Mohammad Molla; Taghipour, Nader

    2017-01-01

    Emerging and hazardous environmental pollutants like phthalic acid esters (PAEs) are one of the recent concerns worldwide. PAEs are considered to have diverse endocrine disrupting effects on human health. Industrial wastewater has been reported as an important environment with high concentrations of PAEs. In the present study, four short-chain PAEs including diallyl phthalate (DAP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and phthalic acid (PA) were selected as a substrate for anaerobic fixed film fixed bed reactor (AnFFFBR). The process performances of AnFFFBR, and also its kinetic behavior, were evaluated to find the best eco-friendly phthalate from the biodegradability point of view. According to the results and kinetic coefficients, removing and mineralizing of DMP occurred at a higher rate than other phthalates. In optimum conditions 92.5, 84.41, and 80.39% of DMP, COD, and TOC were removed. DAP was found as the most bio-refractory phthalate. The second-order (Grau) model was selected as the best model for describing phthalates removal. PMID:28216654

  15. Anaerobic acidogenic digestion of olive mill wastewaters in biofilm reactors packed with ceramic filters or granular activated carbon.

    Science.gov (United States)

    Bertin, Lorenzo; Lampis, Silvia; Todaro, Daniela; Scoma, Alberto; Vallini, Giovanni; Marchetti, Leonardo; Majone, Mauro; Fava, Fabio

    2010-08-01

    Four identically configured anaerobic packed bed biofilm reactors were developed and employed in the continuous acidogenic digestion of olive mill wastewaters to produce volatile fatty acids (VFAs), which can be exploited in the biotechnological production of polyhydroxyalkanoates. Ceramic porous cubes or granular activated carbon were used as biofilm supports. Aside packing material, the role of temperature and organic loading rate (OLR) on VFA production yield and mixture composition were also studied. The process was monitored through a chemical, microbiological and molecular biology integrated procedure. The highest wastewater acidification yield was achieved with the ceramic-based technology at 25 degrees C, with an inlet COD and an OLR of about 17 g/L and 13 g/L/day, respectively. Under these conditions, about the 66% of the influent COD (not including its VFA content) was converted into VFAs, whose final amount represented more than 82% of the influent COD. In particular, acetic, propionic and butyric acids were the main VFAs by composing the 55.7, 21.5 and 14.4%, respectively, of the whole VFA mixture. Importantly, the relative concentrations of acetate and propionate were affected by the OLR parameter. The nature of the packing material remarkable influenced the process performances, by greatly affecting the biofilm bacterial community structure. In particular, ceramic cubes favoured the immobilization of Firmicutes of the genera Bacillus, Paenibacillus and Clostridium, which were probably involved in the VFA producing process.

  16. Performance, kinetic, and biodegradation pathway evaluation of anaerobic fixed film fixed bed reactor in removing phthalic acid esters from wastewater

    Science.gov (United States)

    Ahmadi, Ehsan; Yousefzadeh, Samira; Ansari, Mohsen; Ghaffari, Hamid Reza; Azari, Ali; Miri, Mohammad; Mesdaghinia, Alireza; Nabizadeh, Ramin; Kakavandi, Babak; Ahmadi, Peyman; Badi, Mojtaba Yegane; Gholami, Mitra; Sharafi, Kiomars; Karimaei, Mostafa; Ghoochani, Mahboobeh; Brahmand, Masoud Binesh; Mohseni, Seyed Mohsen; Sarkhosh, Maryam; Rezaei, Soheila; Asgharnia, Hosseinali; Dehghanifard, Emad; Jafari, Behdad; Mortezapour, Alireza; Moghaddam, Vahid Kazemi; Mahmoudi, Mohammad Molla; Taghipour, Nader

    2017-02-01

    Emerging and hazardous environmental pollutants like phthalic acid esters (PAEs) are one of the recent concerns worldwide. PAEs are considered to have diverse endocrine disrupting effects on human health. Industrial wastewater has been reported as an important environment with high concentrations of PAEs. In the present study, four short-chain PAEs including diallyl phthalate (DAP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and phthalic acid (PA) were selected as a substrate for anaerobic fixed film fixed bed reactor (AnFFFBR). The process performances of AnFFFBR, and also its kinetic behavior, were evaluated to find the best eco-friendly phthalate from the biodegradability point of view. According to the results and kinetic coefficients, removing and mineralizing of DMP occurred at a higher rate than other phthalates. In optimum conditions 92.5, 84.41, and 80.39% of DMP, COD, and TOC were removed. DAP was found as the most bio-refractory phthalate. The second-order (Grau) model was selected as the best model for describing phthalates removal.

  17. Effects of operational factors on soluble microbial products in a carrier anaerobic baffled reactor treating dilute wastewater

    Institute of Scientific and Technical Information of China (English)

    FENG Huajun; HU Lifang; SHAN Dan; FANG Chengran; HE Yonghua; SHEN Dongsheng

    2008-01-01

    The effects of feed strength,hydraulic residence time(HRT),and operational temperatures on soluble microbial product(SMP) production were investigated,to gain insights into the production mechanism.A carrier anaerobic batfled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions,namely,feed strengths of 300-600 mg/L,HRTs of 9-18 h,and temperatures of 10-28℃.Generally, SMP production increased with increasing feed strength and decreasing temperature.At high temperature (28℃),SMP production increased with decreasing HRT. As the temperature Was decreased to 18 and 10℃.the SMP production was at its peak for 12 h HRT Therefore,temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio Was found at high temperature and long HRT because of complete volatile fatty acid degradation.SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR.As a secondary metabolite.some SMP could be consumed at lower feed strength.

  18. Anaerobic co-digestion of chicken manure and corn stover in batch and continuously stirred tank reactor (CSTR).

    Science.gov (United States)

    Li, Yeqing; Zhang, Ruihong; He, Yanfeng; Zhang, Chenyu; Liu, Xiaoying; Chen, Chang; Liu, Guangqing

    2014-03-01

    Anaerobic co-digestion of chicken manure and corn stover in batch and CSTR were investigated. The batch co-digestion tests were performed at an initial volatile solid (VS) concentration of 3gVS/L, carbon-to-nitrogen (C/N) ratio of 20, and retention time of 30d. The methane yield was determined to be 281±12mL/gVSadded. Continuous reactor was carried out with feeding concentration of 12% total solids and C/N ratio of 20 at organic loading rates (OLRs) of 1-4gVS/L/d. Results showed that at OLR of 4gVS/L/d, stable and preferable methane yield of 223±7mL/gVSadded was found, which was equal to energy yield (EY) of 8.0±0.3MJ/kgVSadded. Post-digestion of digestate gave extra EY of 1.5-2.6MJ/kgVSadded. Pyrolysis of digestate provided additional EY of 6.1MJ/kgVSadded. Pyrolysis can be a promising technique to reduce biogas residues and to produce valuable gas products simultaneously.

  19. Organic loading rate impact on biohydrogen production and microbial communities at anaerobic fluidized thermophilic bed reactors treating sugarcane stillage.

    Science.gov (United States)

    Santos, Samantha Christine; Rosa, Paula Rúbia Ferreira; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

    2014-05-01

    This study aimed to evaluate the effect of high organic loading rates (OLR) (60.0-480.00 kg COD m(-3)d(-1)) on biohydrogen production at 55°C, from sugarcane stillage for 15,000 and 20,000 mg CODL(-1), in two anaerobic fluidized bed reactors (AFBR1 and AFBR2). It was obtained, for H2 yield and content, a decreasing trend by increasing the OLR. The maximum H2 yield was observed in AFBR1 (2.23 mmol g COD added(-1)). The volumetric H2 production was proportionally related to the applied hydraulic retention time (HRT) of 6, 4, 2 and 1h and verified in AFBR1 the highest value (1.49 L H2 h(-1)L(-1)). Among the organic acids obtained, there was a predominance of lactic acid (7.5-22.5%) and butyric acid (9.4-23.8%). The microbial population was set with hydrogen-producing fermenters (Megasphaera sp.) and other organisms (Lactobacillus sp.).

  20. Reduction of COD and Turbidity of Effluent in the Swine Productions Unit Employing Anaerobic Baffled Reactor (ABR Followed by Biological Filters and Sand Filter

    Directory of Open Access Journals (Sweden)

    Euzebio Beli

    2010-04-01

    Full Text Available The growing swine production is constantly in conflict with the environment due to the lack of environmental management directed to the cycle of animal production and the industrial sector, mainly due to the mishandling of slurry produced. In association with large concentrations of confined animals appear huge dumps of organic matter, inorganic nutrients and gaseous emissions, which require special care for its disposal to the environment. The aim of this study was to evaluate the use of an anaerobic baffled reactor (ABR in series with two downflow biological filters, followed by a sand filter as a polishing treatment. It were analyzed the reduction of COD and turbidity, and the behavior of pH in all phases of treatment. The removal of COD in the conjugated system, which occurred during treatment ranged from 74.55% to 94.41% with an average removal of 84.24%. In turn, the removal of turbidity from the period ranged from 53.07% to 96.11% with an average removal of 85.49%. In the studied period the pH changed from 5,6 to 8,4. This system was efficient in the removal of COD and turbidity of swine wastewater.

  1. Development of a system model for advanced small modular reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tom Goslee,; Holschuh, Thomas Vernon,

    2014-01-01

    This report describes a system model that can be used to analyze three advance small modular reactor (SMR) designs through their lifetime. Neutronics of these reactor designs were evaluated using Monte Carlo N-Particle eXtended (MCNPX/6). The system models were developed in Matlab and Simulink. A major thrust of this research was the initial scoping analysis of Sandias concept of a long-life fast reactor (LLFR). The inherent characteristic of this conceptual design is to minimize the change in reactivity over the lifetime of the reactor. This allows the reactor to operate substantially longer at full power than traditional light water reactors (LWRs) or other SMR designs (e.g. high temperature gas reactor (HTGR)). The system model has subroutines for lifetime reactor feedback and operation calculations, thermal hydraulic effects, load demand changes and a simplified SCO2 Brayton cycle for power conversion.

  2. Production of hydrogen in a granular sludge-based anaerobic continuous stirred tank reactor

    Energy Technology Data Exchange (ETDEWEB)

    Show, Kuan-Yeow [Faculty of Engineering and Science, University of Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur (Malaysia); Zhang, Zhen-Peng; Tay, Joo-Hwa [School of Civil and Environmental Engineering, Nanyang Technological University, 639798 (Singapore); Institute of Environmental Science and Engineering, Nanyang Technological University, 637723 (Singapore); Tee Liang, David [Institute of Environmental Science and Engineering, Nanyang Technological University, 637723 (Singapore); Lee, Duu-Jong [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan, RO (China); Jiang, Wen-Ju [Department of Environmental Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2007-12-15

    An investigation on biohydrogen production was conducted in a granular sludge-based continuous stirred tank reactor (CSTR). The reactor performance was assessed at five different glucose concentrations of 2.5, 5, 10, 20 and 40 g/L and four hydraulic retention times (HRTs) of 0.25, 0.5, 1 and 2 h, resulting in the organic loading rates (OLRs) ranged between 2.5 and 20 g-glucose/L h. Carbon flow was traced by analyzing the composition of gaseous and soluble metabolites as well as the cell yield. Butyrate, acetate and ethanol were found to be the major soluble metabolite products in the biochemical synthesis of hydrogen. Carbon balance analysis showed that more than half of the glucose carbon was converted into unidentified soluble products at an OLR of 2.5 g-glucose/L h. It was found that high hydrogen yields corresponded to a sludge loading rate in between 0.6 and 0.8 g-glucose/g-VSS h. Substantial suppression in hydrogen yield was noted as the sludge loading rate fell beyond the optimum range. It is deduced that decreasing the sludge loading rate induced the metabolic shift of biochemical reactions at an OLR of 2.5 g-glucose/L h, which resulted in a substantial reduction in hydrogen yield to 0.36-0.41 mol-H{sub 2}/mol-glucose. Optimal operation conditions for peak hydrogen yield (1.84 mol-H{sub 2}/mol-glucose) and hydrogen production rate (3.26 L/L h) were achieved at an OLR of 20 g-glucose/L h, which corresponded to an HRT of 0.5 h and an influent glucose concentration of 10 g/L. Influence of HRT and substrate concentration on the reactor performance was interrelated and the adverse impact on hydrogen production was noted as substrate concentration was higher than 20 g/L or HRT was shorter than 0.5 h. The experimental study indicated that a higher OLR derived from appropriate HRTs and substrate concentrations was desirable for hydrogen production in such a granule-based CSTR. (author)

  3. Microbial succession within an anaerobic sequencing batch biofilm reactor (ASBBR treating cane vinasse at 55ºC

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Ferreira Ribas

    2009-08-01

    Full Text Available The aim of this work was to investigate the anaerobic biomass formation capable of treating vinasse from the production of sugar cane alcohol, which was evolved within an anaerobic sequencing batch biofilm reactor (ASBBR as immobilized biomass on cubes of polyurethane foam at the temperature of 55ºC. The reactor was inoculated with mesophilic granular sludge originally treating poultry slaughterhouse wastewater. The evolution of the biofilm in the polyurethane foam matrices was assessed during seven experimental phases which were thus characterized by the changes in the organic matter concentrations as COD (1.0 to 20.0 g/L. Biomass characterization proceeded with the examination of sludge samples under optical and scanning electron microscopy. The reactor showed high microbial morphological diversity along the trial. The predominance of Methanosaeta-like cells was observed up to the organic load of 2.5 gCOD/L.d. On the other hand, Methanosarcinalike microorganisms were the predominant archaeal population within the foam matrices at high organic loading ratios above 3.3 gCOD/L.d. This was suggested to be associated to a higher specific rate of acetate consumption by the later organisms.Este trabalho investigou a formação de um biofilme anaeróbio capaz de tratar vinhaça da produção de álcool de cana-de-açúcar, que evoluiu dentro de um reator operado em bateladas seqüenciais com biofilme (ASBBR tendo a biomassa imobilizada em cubos de espuma de poliuretano na temperatura de 55ºC. O reator foi inoculado com lodo granular mesofílico tratando água residuária de abatedouro de aves. A evolução do biofilme nas matrizes de espuma de poliuretano foi observada durante sete fases experimentais que foram caracterizadas por mudanças nas concentrações de matéria orgânica como DQO (1,0 a 20,0 g/L. A caracterização da biomassa foi feita por exames de amostras do lodo em microscopia ótica e eletrônica de varredura. O reator apresentou

  4. ADAPTIVE CONTROL SYSTEM OF INDUSTRIAL REACTORS

    Directory of Open Access Journals (Sweden)

    Vyacheslav K. Mayevski

    2014-01-01

    Full Text Available This paper describes a mathematical model of an industrial chemical reactor for production of synthetic rubber. During reactor operation the model parameters vary considerably. To create a control algorithm performed transformation of mathematical model of the reactor in order to obtain a dependency that can be used to determine the model parameters are changing during reactor operation.

  5. Characterization and treatment of Denizli landfill leachate using anaerobic hybrid/aerobic CSTR systems.

    Science.gov (United States)

    Ağdağ, Osman Nuri

    2011-01-01

    Leachate generated in municipal solid waste landfill contains large amounts of organic and inorganic contaminants. In the scope of the study, characterization and anaerobic/aerobic treatability of leachate from Denizli (Turkey) Sanitary Landfill were investigated. Time-based fluctuations in characteristics of leachate were monitored during a one-year period. In characterization study; chemical oxygen demand (COD), biochemical oxygen demand (BOD) dissolved oxygen, temperature, pH, alkalinity, volatile fatty acids, total nitrogen, NH4-N, BOD5/COD ratio, suspended solid, inert COD, anaerobic toxicity assay and heavy metals concentrations in leachate were monitored. Average COD, BOD and NH4-N concentration in leachate were measured as 18034 mg/l, 11504 mg/l and 454 mg/l, respectively. Generally, pollution parameters in leachate were higher in summer and relatively lower in winter due to dilution by precipitation. For treatment of leachate, two different reactors, namely anaerobic hybrid and aerobic completely stirred tank reactor (CSTR) having effective volumes of 17.7 and 10.5 litres, respectively, were used. After 41 days of start-up period, leachate was loaded to hybrid reactor at 10 different organic loading rates (OLRs). OLR was increased by increasing COD concentrations. COD removal efficiency of hybrid reactor was carried out at a maximum of 91%. A percentage of 96% of residual COD was removed in the aerobic reactor. NH4-N removal rate in CSTR was quite high. In addition, high methane content was obtained as 64% in the hybrid reactor. At the end of the study, after 170 operation days, it can be said that the hybrid reactor and CSTR were very effective for leachate treatment.

  6. Recovery of gastrointestinal swine parasites in anaerobic biodigester systems.

    Science.gov (United States)

    Cañon-Franco, William Alberto; Henao-Agudelo, Ricardo Andrés; Pérez-Bedoya, José Leandro

    2012-01-01

    Solid and liquid wastes from livestock operations represent important challenges for animal production regarding their impact in the environment and public health. Parasitological tests performed on 80 samples of affluent and effluent waters from three anaerobic biodigestors with flexible structure from swine farms of Caldas - Colombia, showed the presence of Isospora suis (45%), Eimeria suis (42.5%), E. espinosa (35%), Strongyloides ransomi (28.8%), E. perminuta (12.5%), E. cerdonis (3.8%), and E. porci (2.5%). The additional finding of eggs of Taenia spp. in 10% of the samples was probably caused by a connection between the human sewage system and the biodigester. Although we observed a mean decrease of 65.6% of parasites, these levels were insufficient to meet the minimum requirement set by Engelberg's guidelines regarding water quality. This study demonstrates the serious environmental impact that an inadequately treated animal wastewater represents, and has important implications for water resources and human health.

  7. Enhancement of the performance of an anaerobic sequencing batch reactor treating low-strength wastewater through implementation of a variable stirring rate program

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, J.A.D.; Pinto, A.G.; Ratusznei, S.M.; Gedraite, R. [Instituto Maua de Tecnologia (IMT), Sao Caetano do Sul, SP (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica e de Alimentos]. E-mail: rodrigues@maua.br; Zaiat, M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Hidraulica e Saneamento

    2004-09-01

    This work focuses on enhancement of the performance of an anaerobic sequencing batch reactor with a six-vertical-blade-disk-turbine impeller, containing granulated biomass treating low-strength synthetic wastewater, through a study of the feasibility of implementing a variable stirring rate program. The reactor was operated at 30 deg C and a six-hour cycle was used to treat approximately 2.0 L of the synthetic substrate with a chemical oxygen demand (COD) of nearly 500 mg/L. Two different stirring rate program were implemented: a constant rate of 50 rpm and a variable rate consisting of 75 rpm for one hour, 50 rpm for four hours and 25 rpm for 0.5 hour. The last 0.5 hour of the cycle was used for the settling step. In both cases, a very short start-up period and unfiltered and filtered substrate removal efficiencies of 81% and 88%, respectively, were attained. However, use of the variable stirring rate enhanced efficiency of the reactor dynamics without impairing biomass morphology, thus resulting in a reduction in the total cycle time and a possible decrease in energy consumption. Additionally, a simplified model of the anaerobic metabolic activity, using apparent kinetic parameters, was proposed as a consecutive first-order kinetic model with substrate and total volatile acid residual concentrations in order to analyze how the variable stirring rate affects reactor performance. (author)

  8. Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production.

    Science.gov (United States)

    Barros, Aruana Rocha; Adorno, Maria Angela Tallarico; Sakamoto, Isabel Kimiko; Maintinguer, Sandra Imaculada; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

    2011-02-01

    This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30°C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8h. The reactor R1 operating with a HRT of 2h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2)mol(-1) glucose with 1.3mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter.

  9. Kinetics and dynamic modelling of batch anaerobic digestion of municipal solid waste in a stirred reactor.

    Science.gov (United States)

    Nopharatana, Annop; Pullammanappallil, Pratap C; Clarke, William P

    2007-01-01

    A series of batch, slurry anaerobic digestion experiments were performed where the soluble and insoluble fractions, and unwashed MSW were separately digested in a 200l stirred stainless steel vessel at a pH of 7.2 and a temperature of 38 degrees C. It was found that 7% of the total MSW COD was readily soluble, of which 80% was converted to biogas; 50% of the insoluble fraction was solubilised, of this only 80% was converted to biogas. The rate of digesting the insoluble fraction was about four times slower than the rate of digesting the soluble fraction; 48% of the total COD was converted to biogas and 40% of the total nitrogen was converted to ammonia. Soluble and insoluble fractions were broken down simultaneously. The minimum time to convert 95% of the degradable fraction to biogas was 20 days. The lag phase for the degradation of insoluble fraction of MSW can be overcome by acclimatising the culture with the soluble fraction. The rate of digestion and the methane yield was not affected by particle size (within the range of 2-50mm). A dynamic model was developed to describe batch digestion of MSW. The parameters of the model were estimated using data from the separate digestion of soluble and insoluble fractions and validated against data from the digestion of unwashed MSW. Trends in the specific aceticlastic and formate-utilising methanogenic activity were used to estimate initial methanogenic biomass concentration and bacterial death rate coefficient. The kinetics of hydrolysis of insoluble fraction could be adequately described by a Contois equation and the kinetics of acidogenesis, and aceticlastic and hydrogen utilising methanogenesis by Monod equations.

  10. Physical-chemical and operational performance of an anaerobic baffled reactor (ABR treating swine wastewater - 10.4025/actascitechnol.v32i4.7203

    Directory of Open Access Journals (Sweden)

    Erlon Lopes Pereira

    2010-12-01

    Full Text Available Since hog raising concentrates a huge amount of swine manure in small areas, it is considered by the environmental government organizations to be one of the most potentially pollutant activities. Therefore the main objective of this research was to evaluate by operational criteria and removal efficiency, the performance of a Anaerobic Baffled Reactor (ABR, working as a biological pre-treatment of swine culture effluents. The physical-chemical analyses carried out were: total COD, BOD5, total solids (TS, fix (TFS and volatiles (TVS, temperature, pH, total Kjeldahl nitrogen, phosphorus, total acidity and alkalinity. The ABR unit worked with an average efficiency of 65.2 and 76.2%, respectively, concerning total COD and BOD5, with a hydraulic retention time (HRT about 15 hours. The results for volumetric organic loading rate (VOLR, organic loading rate (OLR and hydraulic loading rate (HLR were: 4.46 kg BOD m-3 day-1; 1.81 kg BOD5 kg TVS-1 day-1 and 1.57 m3 m-3 day-1, respectively. The average efficiency of the whole treatment system for total COD and BOD5 removal were 66.5 and 77.8%, showing an adequate performance in removing the organic matter from swine wastewater.

  11. Anaerobic digester for treatment of organic waste

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V. K. [Indian Insitute of Technology, Delhi (India)]|[ENEA, Centro Ricerche Trisaia, Matera (Italy); Fortuna, F.; Canditelli, M.; Cornacchia, G. [ENEA, Centro Ricerche Trisaia, Matera (Italy). Dipt. Ambiente; Farina, R. [ENEA, centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Ambiente

    1997-09-01

    The essential features of both new and more efficient reactor systems and their appropriate applications for various organic waste management situations, description of several working plants are discussed in the present communication. It is hoped that significant development reported here would be useful in opening a new vista to the application of anaerobic biotechnology for the waste treatment of both low/high organic strength and specialized treatment for toxic substances, using appropriate anaerobic methods.

  12. Evaluation Of Communal Wastewater Treatment Plant Operating Anaerobic Baffled Reactor And Biofilter

    Directory of Open Access Journals (Sweden)

    Evy Hendriarianti

    2016-02-01

    Full Text Available Construction of communal Waste Water Treatment Plant, WWTP in city of Malang since 1998 but until recently had never done an evaluation the performance. Communal WWTP performance evaluation is needed to see how far the efficiency of processing result. Until now, Environmental Agency Malang City only measure effluent from WWTP Communal  to know the suitability  with domestic wastewater quality standards. Effluent quality data in 2014 showed value above the quality standard of domestic wastewater from East Java Governor Regulation No. 72 in 2013 for parameters BOD and COD. WWTP Communal USRI research objects are on a six (6 locations by involving the user community during the planning, construction, operation and maintenance. Technology choice of ABR followed by a biofilter reactor with the stone media proved capable of processing organic matter of BOD and COD with the removal levels respectively by 78% -99% and 71% -99%. As for the parameters of TSS, NO3 and PO4 have the ranges of removal respectively by 56% -100%, (43% - 72%, (2% - 13%. Ratio BOD and COD in influent are low and ranged from 0.22 to 0.41. From the evaluation shows that high organic matter concentrations in influent along with the HRT and operation time high will result in a higher removal level

  13. Inoculum composition determines microbial community and function in an anaerobic sequential batch reactor.

    Science.gov (United States)

    Perrotta, Allison R; Kumaraswamy, Rajkumari; Bastidas-Oyanedel, Juan R; Alm, Eric J; Rodríguez, Jorge

    2017-01-01

    The sustainable recovery of resources from wastewater streams can provide many social and environmental benefits. A common strategy to recover valuable resources from wastewater is to harness the products of fermentation by complex microbial communities. In these fermentation bioreactors high microbial community diversity within the inoculum source is commonly assumed as sufficient for the selection of a functional microbial community. However, variability of the product profile obtained from these bioreactors is a persistent challenge in this field. In an attempt to address this variability, the impact of inoculum on the microbial community structure and function within the bioreactor was evaluated using controlled laboratory experiments. In the course of this work, sequential batch reactors were inoculated with three complex microbial inocula and the chemical and microbial compositions were monitored by HPLC and 16S rRNA amplicon analysis, respectively. Microbial community dynamics and chemical profiles were found to be distinct to initial inoculate and highly reproducible. Additionally we found that the generation of a complex volatile fatty acid profile was not specific to the diversity of the initial microbial inoculum. Our results suggest that the composition of the original inoculum predictably contributes to bioreactor community structure and function.

  14. Inoculum composition determines microbial community and function in an anaerobic sequential batch reactor

    Science.gov (United States)

    Perrotta, Allison R.; Kumaraswamy, Rajkumari; Bastidas-Oyanedel, Juan R.; Alm, Eric J.

    2017-01-01

    The sustainable recovery of resources from wastewater streams can provide many social and environmental benefits. A common strategy to recover valuable resources from wastewater is to harness the products of fermentation by complex microbial communities. In these fermentation bioreactors high microbial community diversity within the inoculum source is commonly assumed as sufficient for the selection of a functional microbial community. However, variability of the product profile obtained from these bioreactors is a persistent challenge in this field. In an attempt to address this variability, the impact of inoculum on the microbial community structure and function within the bioreactor was evaluated using controlled laboratory experiments. In the course of this work, sequential batch reactors were inoculated with three complex microbial inocula and the chemical and microbial compositions were monitored by HPLC and 16S rRNA amplicon analysis, respectively. Microbial community dynamics and chemical profiles were found to be distinct to initial inoculate and highly reproducible. Additionally we found that the generation of a complex volatile fatty acid profile was not specific to the diversity of the initial microbial inoculum. Our results suggest that the composition of the original inoculum predictably contributes to bioreactor community structure and function. PMID:28196102

  15. Successful treatment of high azo dye concentration wastewater using combined anaerobic/aerobic granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR): simultaneous adsorption and biodegradation processes.

    Science.gov (United States)

    Hosseini Koupaie, E; Alavi Moghaddam, M R; Hashemi, S H

    2013-01-01

    The application of a granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR) for treatment of wastewater containing 1,000 mg/L Acid Red 18 (AR18) was investigated in this research. The treatment system consisted of a sequencing batch reactor equipped with moving GAC as biofilm support. Each treatment cycle consisted of two successive anaerobic (14 h) and aerobic (8 h) reaction phases. Removal of more than 91% chemical oxygen demand (COD) and 97% AR18 was achieved in this study. Investigation of dye decolorization kinetics showed that the dye removal was stimulated by the adsorption capacity of the GAC at the beginning of the anaerobic phase and then progressed following a first-order reaction. Based on COD analysis results, at least 77.8% of the dye total metabolites were mineralized during the applied treatment system. High-performance liquid chromatography analysis revealed that more than 97% of 1-naphthyalamine-4-sulfonate as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase. According to the scanning electron microscopic analysis, the microbial biofilms grew in most cavities and pores of the GAC, but not on the external surfaces of the GAC.

  16. Anaerobic co-culture of mesenchymal stem cells and anaerobic pathogens - a new in vitro model system.

    Directory of Open Access Journals (Sweden)

    Katja Kriebel

    Full Text Available BACKGROUND: Human mesenchymal stem cells (hMSCs are multipotent by nature and are originally isolated from bone marrow. In light of a future application of hMSCs in the oral cavity, a body compartment with varying oxygen partial pressures and an omnipresence of different bacterial species i.e. periodontitis pathogens, we performed this study to gain information about the behavior of hMSC in an anaerobic system and the response in interaction with oral bacterial pathogens. METHODOLOGY/PRINCIPAL FINDINGS: We established a model system with oral pathogenic bacterial species and eukaryotic cells cultured in anaerobic conditions. The facultative anaerobe bacteria Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were studied. Their effects on hMSCs and primary as well as permanent gingival epithelial cells (Ca9-22, HGPEC were comparatively analyzed. We show that hMSCs cope with anoxic conditions, since 40% vital cells remain after 72 h of anaerobic culture. The Ca9-22 and HGPEC cells are significantly more sensitive to lack of oxygen. All bacterial species reveal a comparatively low adherence to and internalization into hMSCs (0.2% and 0.01% of the initial inoculum, respectively. In comparison, the Ca9-22 and HGPEC cells present better targets for bacterial adherence and internalization. The production of the pro-inflammatory chemokine IL-8 is higher in both gingival epithelial cell lines compared to hMSCs and Fusobacterium nucleatum induce a time-dependent cytokine secretion in both cell lines. Porphyromonas gingivalis is less effective in stimulating secretion of IL-8 in the co-cultivation experiments. CONCLUSIONS/SIGNIFICANCE: HMSCs are suitable for use in anoxic regions of the oral cavity. The interaction with local pathogenic bacteria does not result in massive pro-inflammatory cytokine responses. The test system established in this study allowed further investigation of parameters prior to set up of

  17. Remoción anaerobia del colorante azul directo brl en Reactor Anaerobio de Flujo Ascendente UASB (Upflow Anaerobic Sludge Blanket con carbón activado

    Directory of Open Access Journals (Sweden)

    Christian Zavala-Rivera

    2015-11-01

    Full Text Available In this research the brl direct blue dye was used for anaerobic removal with a bacterial consortium of industrial effluents from Industrial Park Río Seco (IPRS, Arequipa, Peru; in an anaerobic reactor of UASB Upflow with activated carbon. The reactor had a capacity of 14.4 L with sludge and activated carbon of 40% of volume, with an organic load of 6 Kg COD/m3•dia and a hydraulic retention time of 1 day with an upward flow. The objective was to measure the efficiency of the anaerobic removal of coloring in a time of 28 days. The results showed an increase of 41% of the solids suspended volatile (SSV 12894 mg•L-1 up to 21546 mg•L-1 under the conditions of the experiment, with a removal of 57% of the chemical demand of oxygen (COD from 484 mg•L-1 to 122 mg•L-1 and a removal of 87% of the dye Blue direct the 69.61 brl mg•L-1 to 9 mg•L-1. Results with activated charcoal granular only, they showed a removal of 61% of the dye Blue direct 70.67 brl mg•L-1 to 27.83 mg•L-1 at 28 days.

  18. Integrated systems analysis of the PIUS reactor

    Energy Technology Data Exchange (ETDEWEB)

    Fullwood, F.; Kroeger, P.; Higgins, J. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1993-11-01

    Results are presented of a systems failure analysis of the PIUS plant systems that are used during normal reactor operation and postulated accidents. This study was performed to provide the NRC with an understanding of the behavior of the plant. The study applied two diverse failure identification methods, Failure Modes Effects & Criticality Analysis (FMECA) and Hazards & Operability (HAZOP) to the plant systems, supported by several deterministic analyses. Conventional PRA methods were also used along with a scheme for classifying events by initiator frequency and combinations of failures. Principal results of this study are: (a) an extensive listing of potential event sequences, grouped in categories that can be used by the NRC, (b) identification of support systems that are important to safety, and (c) identification of key operator actions.

  19. Effect of pentachlorophenol and chemical oxygen demand mass concentrations in influent on operational behaviors of upflow anaerobic sludge blanket (UASB) reactor.

    Science.gov (United States)

    Shen, Dong-Sheng; He, Ruo; Liu, Xin-Wen; Long, Yan

    2006-08-25

    Upflow anaerobic sludge blanket (UASB) reactor that was seeded with anaerobic sludge acclimated to chlorophenols was used to investigate the feasibility of anaerobic biotreatment of synthetic wastewater containing pentachlorophenol (PCP) with additional sucrose as carbon source. Two sets of UASB reactors were operated at one time. But the seeded sludge for the two reactors was different and Reactor I was seeded with the sludge that was acclimated to PCP completely for half a year, and Reactor II was seeded with the mixed sludge that was acclimated for half a year to PCP, 4-CP, 3-CP or 2-CP, respectively. The degradation of PCP and the operation fee treating the wastewater are affected by the concentration of MEDS (microorganism easily degradable substrate). So the confirmation of the suitable ratio of [COD] and [PCP] was the key factor of treating the wastewater containing PCP economically and efficiently. During the experiment, the synthetic wastewater with 180.0 mg L(-1) PCP and 1250-10000 mg L(-1) COD could be treated steadily in the experimental Reactor I. The removal efficiency of PCP was more than 99.5% and the removal efficiency of COD was up to 90%. [PCP] (concentration of PCP) in effluent was less than 0.5 mg L(-1). [PCP] in influent could affect proper [COD] (concentration of COD) range in influent that was required for maintenance of steady running of the experimental reactor with a hydraulic retention time (HRT) from 20 to 22 h. [PCP] in influent would directly affect the necessary [COD] in influent when the UASB reactor ran normally and treated the wastewater containing PCP. When [PCP] was 100.4, 151.6 and 180.8 mg L(-1) in influent, respectively, [COD] in influent had to be controlled about 1250-7500, 2500-5000 and 5000 mg L(-1) to maintain the UASB reactor steady running normally and contemporarily ensure that [COD] and [PCP] in effluent were less than 300 and 0.5 mg L(-1), respectively. With the increase of [PCP] in influent, the range of variation

  20. Kinetics of para-nitrophenol and chemical oxygen demand removal from synthetic wastewater in an anaerobic migrating blanket reactor.

    Science.gov (United States)

    Kuşçu, Ozlem Selçuk; Sponza, Delia Teresa

    2009-01-30

    A laboratory scale anaerobic migrating blanket reactor (AMBR) was operated at different HRTs (1-10.38 days) in order to determine the para-nitrophenol (p-NP) and COD removal kinetic constants. The reactor was fed with 40 mg L(-1)p-NP and 3000 mg L(-1) glucose-COD. Modified Stover-Kincannon and Grau second-order kinetic models were applied to the experimental data. The predicted p-NP and COD concentrations were calculated using the kinetic constants. It was found that these data were in better agreement with the observed ones in the modified Stover-Kincannon compared to Grau second-order model. The kinetic constants calculated according to Stover-Kincannon model are as follows: the saturation value constant (K(B)) and maximum utilization rate constants (R(max)) were found as 31.55 g CODL(-1)day(-1), 29.49 g CODL(-1)day(-1) for COD removal and 0.428 g p-NPL(-1)day(-1), 0.407 g p-NPL(-1)day(-1) for p-NP removal, respectively (R(2)=1). The values of (a) and (b) were found to be 0.096 day and 1.071 (dimensionless) with high correlation coefficients of R(2)=0.85 for COD removal. Kinetic constants for specific gas production rate were evaluated using modified Stover-Kincannon, Van der Meer and Heerrtjes and Chen and Hasminoto models. It was shown that Stover-Kincannon model is more appropriate for calculating the effluent COD, p-NP concentrations in AMBR compared to the other models. The maximum specific biogas production rate, G(max), and proportionality constant, G(B), were found to be 1666.7 mL L(-1) day(-1) and 2.83 (dimensionless), respectively in modified Stover-Kincannon gas model. The bacteria had low Haldane inhibition constants (K(ID)=14 and 23 mg L(-1)) for p-NP concentrations higher than 40 mg L(-1) while the half velocity constant (K(s)) increased from 10 to 60 and 118 mg L(-1) with increasing p-NP concentrations from 40 to 85 and 125 mg L(-1).

  1. Structural materials challenges for advanced reactor systems

    Science.gov (United States)

    Yvon, P.; Carré, F.

    2009-03-01

    Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials

  2. Production of bioenergy in anaerobic baffled reactor (ABR) and sludge blanket (UASB) in the treatment os swine waste water; Producao de bioenergia em reatores anaerobios compartimentado (RAC) e de manta de lodo (UASB) no tratamento de efluentes de suinocultura

    Energy Technology Data Exchange (ETDEWEB)

    Moterani, Fabricio; Pereira, Erlon Lopes; Campos, Claudio M.M. [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia], email: fabricio_moterani@yahoo.com.br

    2011-07-01

    The biogas is obtained in the processes of degradation of organic matter by the action of bacterial consortium in the environment. The aim of this study was to evaluate the biogas production in anaerobic UASB and ABR in swine wastewater treatment. For this we used the theoretical estimated and actual production of biogas measured by anaerobic gasometers installed in the units. Methane was determined by gas chromatography (GC) and its theoretical output was 66 LCH4 kgSVT d{sup -1} and 11.9 LCH4 kgSVT d{sup -1} and 24.7 m{sup 3} d{sup -1} and 5.4 m{sup 3} d{sup -1} to ABR and UASB, respectively. Regarding the actual production of biogas in the reactor provided by the gas tank, found the values of 1,166.4 m{sup 3}; 0.1 m{sup 3}; 27.4 m{sup 3} and 12,598.5 m{sup 3} of biogas for compartments 1, 2 and 3 and ABR for the UASB reactor, respectively, totaling, production of 13,792.4 m{sup 3} in the units together, with an average of 113 m{sup 3} of biogas per day. But, it concludes with this research that the use of effluent from produce energy through biogas in swine farming is effective, which can be used in rural productive system itself. (author)

  3. Nanoscale zero-valent iron/persulfate enhanced upflow anaerobic sludge blanket reactor for dye removal: Insight into microbial metabolism and microbial community

    Science.gov (United States)

    Pan, Fei; Zhong, Xiaohan; Xia, Dongsheng; Yin, Xianze; Li, Fan; Zhao, Dongye; Ji, Haodong; Liu, Wen

    2017-03-01

    This study investigated the efficiency of nanoscale zero-valent iron combined with persulfate (NZVI/PS) for enhanced degradation of brilliant red X-3B in an upflow anaerobic sludge blanket (UASB) reactor, and examined the effects of NZVI/PS on anaerobic microbial communities during the treatment process. The addition of NZVI (0.5 g/L) greatly enhanced the decolourization rate of X-3B from 63.8% to 98.4%. The Biolog EcoPlateTM technique was utilized to examine microbial metabolism in the reactor, and the Illumina MiSeq high-throughput sequencing revealed 22 phyla and 88 genera of the bacteria. The largest genera (Lactococcus) decreased from 33.03% to 7.94%, while the Akkermansia genera increased from 1.69% to 20.23% according to the abundance in the presence of 0.2 g/L NZVI during the biological treatment process. Meanwhile, three strains were isolated from the sludge in the UASB reactors and identified by 16 S rRNA analysis. The distribution of three strains was consistent with the results from the Illumina MiSeq high throughput sequencing. The X-ray photoelectron spectroscopy results indicated that Fe(0) was transformed into Fe(II)/Fe(III) during the treatment process, which are beneficial for the microorganism growth, and thus promoting their metabolic processes and microbial community.

  4. Anaerobic degradation of azo dye Drimaren blue HFRL in UASB reactor in the presence of yeast extract a source of carbon and redox mediator.

    Science.gov (United States)

    Baêta, B E L; Aquino, S F; Silva, S Q; Rabelo, C A

    2012-04-01

    This paper presents results on anaerobic degradation of the azo dye blue HFRL in a bench scale Upflow anaerobic sludge blanket (UASB) reactor operated at ambient temperature. The results show that the addition of yeast extract (500 mg/L) increased color removal (P dye removal increased along the operational phases and depended on the presence of yeast extract, suggesting progressive biomass acclimatization. Analysis of bacterial diversity by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) method showed there was biomass selection along the bioreactor operation and no evidence of azo dye degrading bacteria predominance. This strengthens the hypothesis that color removal happens extracellularly by the reduction of azo bond by reduced redox mediators, such as riboflavin, which is present in high amount in the yeast extract.

  5. A modular diagnosis system based on fuzzy logic for UASB reactors treating sewage.

    Science.gov (United States)

    Borges, R M; Mattedi, A; Munaro, C J; Franci Gonçalves, R

    A modular diagnosis system (MDS), based on the framework of fuzzy logic, is proposed for upflow anaerobic sludge blanket (UASB) reactors treating sewage. In module 1, turbidity and rainfall information are used to estimate the influent organic content. In module 2, a dynamic fuzzy model is used to estimate the current biogas production from on-line measured variables, such as daily average temperature and the previous biogas flow rate, as well as the organic load. Finally, in module 3, all the information above and the residual value between the measured and estimated biogas production are used to provide diagnostic information about the operation status of the plant. The MDS was validated through its application to two pilot UASB reactors and the results showed that the tool can provide useful diagnoses to avoid plant failures.

  6. Optimizing the performance of a reactor by reducing the retention time and addition of glycerin for anaerobically digesting manure

    NARCIS (Netherlands)

    Timmerman, M.; Schuman, E.; Eekert, M.; Riel, van J.W.

    2015-01-01

    Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on

  7. A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

    DEFF Research Database (Denmark)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2014-01-01

    A new technology for in-situ biogas upgrading and recovery of CH4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO2 from the liquid phase of a biogas reactor. The degassing membrane was submerged into a dega......A new technology for in-situ biogas upgrading and recovery of CH4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO2 from the liquid phase of a biogas reactor. The degassing membrane was submerged......, the COD removal efficiency and CH4 yield were not obviously affected by the gas desorption....

  8. System assessment of helical reactors in comparison with tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, K.; Imagawa, S.; Muroga, T.; Sagara, A.; Okamura, S.

    2002-10-01

    A comparative assessment of tokamak and helical reactors has been performed using equivalent physics/engineering model and common costing model. Higher-temperature plasma operation is required in tokamak reactors to increase bootstrap current fraction and to reduce current-drive (CD) power. In helical systems, lower-temperature operation is feasible and desirable to reduce helical ripple transport. The capital cost of helical reactor is rather high, however, the cost of electricity (COE) is almost same as that of tokamak reactor because of smaller re-circulation power (no CD power) and less-frequent blanket replacement (lower neutron wall loading). The standard LHD-type helical reactor with 5% beta value is economically equivalent to the standard tokamak with 3% beta. The COE of lower-aspect ratio helical reactor is on the same level of high-{beta}{sub N} tokamak reactors. (author)

  9. Coupled anaerobic/aerobic biodegradation of 2,4,6 trichlorophenol

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Degradation of 2, 4, 6-trichlorophenol(TCP) with co-immobilizing anaerobic granular sludge and isolated aerobic bacterial specieswas studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co-immobilized granule mightfacilitate degrading the TCP and exchange of anaerobic metabolites 4-CP, which promoted system organic removal efficiency and recovered fromorganic shock-loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over thecourse of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co-immobilized granule layers,while the interior was characterized by anaerobic activity. The co-immobilized granule could thus enable both aerobic and anaerobic microbesfunction in the same reactor and thereby integrate the oxidative and reductive catabolism.

  10. DNA-Based Enzyme Reactors and Systems

    Directory of Open Access Journals (Sweden)

    Veikko Linko

    2016-07-01

    Full Text Available During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular cargo into cells. In this review, we focus on the latest enzyme systems based on novel DNA nanostructures: enzyme reactors, regulatory devices and carriers that can find uses in various biotechnological and nanomedical applications.

  11. A novel application of red mud-iron on granulation and treatment of palm oil mill effluent using upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Ahmad, Anwar

    2014-01-01

    The performance of the upflow anaerobic sludge blanket reactor that used red mud-iron (RM-Fe) for methane production for the treatment of palm oil mill effluent (POME) at various hydraulic retention time (HRT) was determined. POME was used as the substrate carbon source. The biogas production rate was 1.7 l biogas/h with a methane yield of 0.78 l CH4/g CODremoved and chemical oxygen demand (COD) removal was 85% at POME concentration of 30 g COD/l at HRT 16 h. The reactor R2 showed average methane content of biogas and COD reduction of 78% and 85% at 400 mg/l RM-Fe. Significant increase in the granule diameter (up to 2900 μm) in R2 was compared to control R1 (up to 86 μm) at end of the experiment.

  12. High rate treatment of terephthalic acid production wastewater in a two-stage anaerobic bioreactor

    NARCIS (Netherlands)

    Kleerebezem, R.; Beckers, J.; Pol, L.W.H.; Lettinga, G.

    2005-01-01

    The feasibility was studied of anaerobic treatment of wastewater generated during purified terephthalic acid (PTA) production in two-stage upflow anaerobic sludge blanket (UASB) reactor system. The artificial influent of the system contained the main organic substrates of PTA-wastewater: acetate, be

  13. Microbial decolorization of reactive black-5 in a two-stage anaerobic-aerobic reactor using acclimatized activated textile sludge.

    Science.gov (United States)

    Mohanty, Sagarika; Dafale, Nishant; Rao, Nageswara Neti

    2006-10-01

    A two-stage anaerobic-aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l(-1). The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by > 90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l(-1 )and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV-VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic-aerobic treatment after a reaction period of 2 days.

  14. High Performance Photocatalytic Oxidation Reactor System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Pioneer Astronautics proposes a technology program for the development of an innovative photocatalytic oxidation reactor for the removal and mineralization of...

  15. Investigation of decolorization of textile wastewater in an anaerobic/aerobic biological activated carbon system (A/A BAC).

    Science.gov (United States)

    Pasukphun, N; Vinitnantharat, S; Gheewala, S

    2010-04-01

    The aim of this study is to investigate the decolorization in anaerobic/aerobic biological activated carbon (A/A BAC) system. The experiment was divided into 2 stages; stage I is batch test for preliminary study of dye removal equilibrium time. The preliminary experiment (stage I) provided the optimal data for experimental design of A/A BAC system in SBR (stage II). Stage II is A/A BAC system imitated Sequencing Batch Reactor (SBR) which consist of 5 main periods; fill, react, settle, draw and idle. React period include anaerobic phase followed by aerobic phase. The BAC main media; Granular Activated Carbon (GAC), Mixed Cultures (MC) and Biological Activated Carbon (BAC) were used for dye and organic substances removal in three different solutions; Desizing Agent Solution (DAS), dye Solution (DS) and Synthetic Textile Wastewater (STW). Results indicate that GAC adsorption plays role in dye removal followed by BAC and MC activities, respectively. In the presence desizing agent, decolorization by MC was improved because desizing agent acts as co-substrates for microorganisms. It was found that 50% of dye removal efficiency was achieved in Fill period by MC. GC/MS analysis was used to identify dye intermediate from decolorization. Dye intermediate containing amine group was found in the solution and on BAC surfaces. The results demonstrated that combination of MC and BAC in the system promotes decolorization and dye intermediate removal. In order to improve dye removal efficiency in an A/A BAC system, replacement of virgin GAC, sufficient co-substrates supply and the appropriate anaerobic: aerobic period should be considered.

  16. Biogas production from chicken manure at different organic loading rates in a mesophilic-thermopilic two stage anaerobic system.

    Science.gov (United States)

    Dalkılıc, Kenan; Ugurlu, Aysenur

    2015-09-01

    This study investigates the biogas production from chicken manure at different organic loading rates (OLRs), in a mesophilic-thermophilic two stage anaerobic system. The system was operated on semi continuous mode under different OLRs [1.9 g volatile solids (VS)/L·d - 4.7 g VS/L·d] and total solid (TS) contents (3.0-8.25%). It was observed that the anaerobic bacteria acclimatized to high total ammonia nitrogen concentration (>3000 mg/L) originated as a result of the degradation of chicken manure. High volatile fatty acid concentrations were tolerated by the system due to high pH in the reactors. The maximum average biogas production rate was found as 554 mL/g VSfeed while feeding 2.2 g VS/L-d (2.3% VS - 3.8% TS) to the system. Average methane content of produced biogas was 74% during the study.

  17. Effect of sulfide inhibition and organic shock loading on anaerobic biofilm reactors treating a low-temperature, high-sulfate wastewater.

    Science.gov (United States)

    McDonald, Heather B; Parkin, Gene F

    2009-03-01

    To assess the long-term treatment of sulfate- and carbon-rich wastewater at low temperatures, anaerobic biofilm reactors were operated for over 900 days at 20 degrees C and fed wastewater containing lactate and sulfate. Results showed the reactors could be operated at 20 degrees C with a load rate of 1.3 g-chemical oxygen demand (COD)/L x d or less and a sulfur loading rate (SLR) of 0.2 g-S/L x d, with no significant deterioration in performance. With acclimation periods, load rates of 3.4 g-COD/L x d and SLR of 0.3 g/L x d could be tolerated. Effluent dissolved sulfide and hydrogen sulfide levels were approximately 600 and 150 mg-S/L, respectively, during this period. The effect of organic shock loading was also assessed. Reactors appeared to recover from one, but not two, lactate spikes of approximately 5000 mg-COD/L. Long-term stability was achieved in reactors containing large, stable populations of lactate- and propionate-degrading sulfate-reducing bacteria and aceticlastic methanogens.

  18. Impact of aluminum chloride on process performance and microbial community structure of granular sludge in an upflow anaerobic sludge blanket reactor for natural rubber processing wastewater treatment.

    Science.gov (United States)

    Thanh, Nguyen Thi; Watari, Takahiro; Thao, Tran Phuong; Hatamoto, Masashi; Tanikawa, Daisuke; Syutsubo, Kazuaki; Fukuda, Masao; Tan, Nguyen Minh; Anh, To Kim; Yamaguchi, Takashi; Huong, Nguyen Lan

    In this study, granular sludge formation was carried out using an aluminum chloride supplement in an upflow anaerobic sludge blanket (UASB) reactor treating natural rubber processing wastewater. Results show that during the first 75 days after the start-up of the UASB reactor with an organic loading rate (OLR) of 2.65 kg-COD·m(-3)·day(-1), it performed stably with a removal of 90% of the total chemical oxygen demand (COD) and sludge still remained in small dispersed flocs. However, after aluminum chloride was added at a concentration of 300 mg·L(-1) and the OLR range was increased up to 5.32 kg-COD·m(-3)·day(-1), the total COD removal efficiency rose to 96.5 ± 2.6%, with a methane recovery rate of 84.9 ± 13.4%, and the flocs began to form granules. Massively parallel 16S rRNA gene sequencing of the sludge retained in the UASB reactor showed that total sequence reads of Methanosaeta sp. and Methanosarcina sp., reported to be the key organisms for granulation, increased after 311 days of operation. This indicates that the microbial community structure of the retained sludge in the UASB reactor at the end of the experiment gave a good account of itself in not only COD removal, but also granule formation.

  19. Efficient anaerobic treatment of synthetic textile wastewater in a UASB reactor with granular sludge enriched with humic acids supported on alumina nanoparticles.

    Science.gov (United States)

    Cervantes, Francisco J; Gómez, Rafael; Alvarez, Luis H; Martinez, Claudia M; Hernandez-Montoya, Virginia

    2015-07-01

    A novel technique to co-immobilize humus-reducing microorganisms and humic substances (HS), supported on γ-Al2O3 nanoparticles (NP), by a granulation process in an upflow anaerobic sludge bed (UASB) reactor is reported in the present work. Larger granules (predominantly between 1 and 1.7 mm) were produced using NP coated with HS compared to those obtained with uncoated NP (mostly between 0.25 and 0.5 mm). The HS-enriched granular biomass was then tested for its capacity to achieve the reductive decolorization of the recalcitrant azo dye, reactive red 2 (RR2), in the same UASB reactor operated with a hydraulic residence time of 12 h and with glucose as electron donor. HS-enriched granules achieved higher decolorization and COD removal efficiencies, as compared to the control reactor operated in the absence of HS, in long term operation and applying high concentrations of RR2 (40-400 mg/L). This co-immobilizing technique could be attractive for its application in UASB reactors for the reductive biotransformation of several contaminants, such as nitroaromatics, poly-halogenated compounds, metalloids, among others.

  20. Impact of the substrate loading regime and phosphoric acid supplementation on performance of biogas reactors and microbial community dynamics during anaerobic digestion of chicken wastes.

    Science.gov (United States)

    Belostotskiy, Dmitry E; Ziganshina, Elvira E; Siniagina, Maria; Boulygina, Eugenia A; Miluykov, Vasili A; Ziganshin, Ayrat M

    2015-10-01

    This study evaluates the effects of increasing organic loading rate (OLR) and decreasing hydraulic retention time (HRT) as well as phosphoric acid addition on mesophilic reactors' performance and biogas production from chicken wastes. Furthermore, microbial community composition in reactors was characterized by a 16S rRNA gene-based pyrosequencing analysis. Each step of increasing OLR impacted on the activity of microorganisms what caused a temporary decrease in biogas production. The addition of phosphoric acid resulted in the increased biogas production with values between 361 and 447 mL g(VS)(-1) from day 61 to day 74 compared to control reactor (309-350 mL g(VS)(-1)). With reactors' operation, Bacteroidetes phylotypes were noticeably replaced with Firmicutes representatives, and significant increase of Clostridium sp. was identified. Within Euryarchaeota, Methanosarcina sp. dominated in all analyzed samples, in which high ammonium levels were detected (3.4-4.9 NH4(+)-N g L(-1)). These results can help in better understanding the anaerobic digestion process of simultaneously ammonium/phosphate-rich substrates.

  1. Effect of thermal pre-treatment on inoculum sludge to enhance bio-hydrogen production from alkali hydrolysed rice straw in a mesophilic anaerobic baffled reactor.

    Science.gov (United States)

    El-Bery, Haitham; Tawfik, Ahmed; Kumari, Sheena; Bux, Faizal

    2013-01-01

    The effect of thermal pre-treatment on inoculum sludge for continuous H2 production from alkali hydrolysed rice straw using anaerobic baffled reactor (ABR) was investigated. Two reactors, ABR1 and ABR2, were inoculated with untreated and thermally pre-treated sludge, respectively. Both reactors were operated in parallel at a constant hydraulic retention time of 20 h and organic loading rate ranged from 0.5 to 2.16 g COD/L d. The results obtained indicated that ABR2 achieved a better hydrogen conversion rate and hydrogen yield as compared with ABR1. The hydrogen conversion rates were 30% and 24%, while the hydrogen yields were 1.19 and 0.97 mol H2/mol glucose for ABR2 and ABR1, respectively. Similar trend was observed for chemical oxygen demand (COD) and carbohydrate removal, where ABR2 provided a removal efficiency of 53 +/- 2.3% for COD and 46 +/- 2% for carbohydrate. The microbial community analysis using 16S rRNA phylogeny revealed the presence of different species of bacteria, namely Clostridium, Prevotella, Paludibacter, Ensifer, and Petrimonas within the reactors. Volatile fatty acids generated from ABR1 and ABR2 were mainly in the form of acetate and butyrate and a relatively low fraction ofpropionate was detected in ABR1. Based on these results, thermal pre-treatment ofinoculum sludge is preferable for hydrogen production from hydrolysed rice straw.

  2. LMFBR type reactor and power generation system using the same

    Energy Technology Data Exchange (ETDEWEB)

    Otsubo, Akira.

    1994-02-25

    A reactor core void reactivity of a reactor main body is set to negative or zero. A heat insulation structure is disposed on the inner wall surface of a reactor container. Oxide fuels or nitride fuels are used. A fuel pin cladding tube has a double walled structure having an outer side of stainless steel and an inner side of niobium alloy. Upon imaginary event, boiling is allowed. Even if boiling of coolants should occur by temperature elevation of fuels upon imaginary event, since reactor core fuels comprises oxides or nitrides, they have a heat resistance, further, and since the fuel pin cladding tube has super heat resistance, it has a high temperature strength, so that it is not ruptured and durable to the coolant boiling temperature. Since the reactor core void reactivity is negative or zero, the reactor core is in a subcritical state by the boiling, and the reactor core power is reduced to several % of the rated power. Accordingly, boiling and non-boiling are repeated substantially permanently in the reactor core, during which safety can be kept with no operator's handling. Further, heat generated in the reactor core is gradually removed by an air cooling system for the reactor container. (N.H.).

  3. Evaluation of the impact of organic material on the anaerobic methane and ammonium removal in a membrane aerated biofilm reactor (MABR) based on the multispecies biofilm modeling.

    Science.gov (United States)

    Wu, Jun; Zhang, Yue

    2017-01-01

    The simultaneous nitrogen and methane removal by the combined nitritation, anaerobic ammonium oxidation (anammox), and nitrite dependent anaerobic methane oxidation (n-damo) processes in the membrane aerated biofilm reactor (MABR) offers clear advantages in term of energy saving and greenhouse gas emission mitigation. The rejected water from sludge digestion usually contained high ammonium, COD, and dissolved methane. The impact of influent COD on the anaerobic methane and ammonium removal in an MABR was evaluated in the model based study. The results indicated that the influent COD did not reduce the methane and ammonium removal efficiency at C/N ratio (influent COD/NH4(+)-N) less than 0.1. At high C/N ratio, the oxygen transfer coefficient needed to be increased to achieve high methane and nitrogen removal. Substrate flux analysis indicated that heterotrophic denitrification in the outside layer of biofilm reduced the impact of influent COD. Heterotrophic growth needed to be limited at the outside layer by using NO3(-) as electron acceptor; otherwise, the heterotrophic bacteria would compete NO2(-) and space with anammox and n-damo bacteria in the inner layers and reduce the nitrogen and methane removal efficiency.

  4. REACTOR - a Concept for establishing a System-of-Systems

    Science.gov (United States)

    Haener, Rainer; Hammitzsch, Martin; Wächter, Joachim

    2014-05-01

    REACTOR is a working title for activities implementing reliable, emergent, adaptive, and concurrent collaboration on the basis of transactional object repositories. It aims at establishing federations of autonomous yet interoperable systems (Systems-of-Systems), which are able to expose emergent behaviour. Following the principles of event-driven service-oriented architectures (SOA 2.0), REACTOR enables adaptive re-organisation by dynamic delegation of responsibilities and novel yet coherent monitoring strategies by combining information from different domains. Thus it allows collaborative decision-processes across system, discipline, and administrative boundaries. Interoperability is based on two approaches that implement interconnection and communication between existing heterogeneous infrastructures and information systems: Coordinated (orchestration-based) communication and publish/subscribe (choreography-based) communication. Choreography-based communication ensures the autonomy of the participating systems to the highest possible degree but requires the implementation of adapters, which provide functional access to information (publishing/consuming events) via a Message Oriented Middleware (MOM). Any interconnection of the systems (composition of service and message cascades) is established on the basis of global conversations that are enacted by choreographies specifying the expected behaviour of the participating systems with respect to agreed Service Level Agreements (SLA) required by e.g. national authorities. The specification of conversations, maintained in commonly available repositories also enables the utilisation of systems for purposes (evolving) other than initially intended. Orchestration-based communication additionally requires a central component that controls the information transfer via service requests or event processing and also takes responsibility of managing business processes. Commonly available transactional object repositories are

  5. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

    Energy Technology Data Exchange (ETDEWEB)

    John R. Gallagher

    2001-07-31

    During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the

  6. Ethanol production from wet-exploded wheat straw hydrolysate by thermophilic anaerobic bacterium Thermoanaerobacter BG1L1 in a continuous immobilized reactor

    DEFF Research Database (Denmark)

    Georgieva, Tania I.; Mikkelsen, Marie Just; Ahring, Birgitte Kiær

    2008-01-01

    Thermophilic ethanol fermentation of wet-exploded wheat straw hydrolysate was investigated in a continuous immobilized reactor system. The experiments were carried out in a lab-scale fluidized bed reactor (FBR) at 70C. Undetoxified wheat straw hydrolysate was used (3-12% dry matter), corresponding...

  7. 厌氧发酵反应器内温度场的数值模拟%Numerical Simulation of Anaerobic Fermentation Reactor Temperature Field

    Institute of Scientific and Technical Information of China (English)

    杜越; 刘建禹; 王尚坤; 朱坤展; 贺佳贝

    2017-01-01

    厌氧发酵反应器是沼气发酵工程的重要装置,由于其内部反应十分复杂,因此发酵反应器内的局部流动和传热过程的研究一直是一个颇具研究价值的问题。掌握反应器内的温度分布是厌氧发酵过程控制工艺优化的基础,对反应器的温度控制起着至关重要的作用。为此,采用 CFD (计算流体力学)的数值模拟方法对发酵料液内的温度场、速度场进行模拟,分析了反应器内料液的流动和换热情况。由于发酵料液的流动速度非常微小,基本可以忽略不计,因此反应器内部料液与反应器侧壁和地面之间热量传递方式以导热为主,可以忽略对流换热作用。由此为今后进一步研究提供理论依据。%Anaerobic fermentation reactor is an important means of biogas projects. Because of its internal reaction is very complex, therefore, studying the local flow and heat transfer process of fermentation in the reactor has been a considera-ble research with great value. Grasping the temperature distribution in the reactor is the basis for the anaerobic fermenta-tion process to optimize the technology. It plays a vital role in controlling the temperature of reactor. In this paper, CFD ( computational fluid dynamics) numerical simulation method is adopted at the temperature field, velocity field within the fermentation liquid simulation. The liquid flow and heat transfer are analyzed. Since fermentation liquid flow rate is very small, basically negligible. Thus, the inside of the reactor with the reactor feed liquid heat transfer between the sidewall and the ground-based approach to the thermal conductivity, convective heat transfer effect can be ignored. It can provide a theoretical basis for further study in the future.

  8. Anaerobic lipid degradation through acidification and methanization.

    Science.gov (United States)

    Kim, Ijung; Kim, Sang-Hyoun; Shin, Hang-Sik; Jung, Jin-Young

    2010-01-01

    In biological wastewater treatment high lipid concentration is known to inhibit microorganisms and cause active biomass flotation. To reduce lipid inhibition, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor, was applied to synthetic dairy wastewater. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid and volatile fatty acid (VFA) removal efficiencies were more than 80%, 70% and 95%, respectively, up to organic loading rate 6.5 g COD/L/day. There were no operational problems such as serious scum formation or sludge washout. Protein degradation occurred prior to degradation during acidogenesis.

  9. 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.

  10. Application of Hastelloy X in Gas-Cooled Reactor Systems

    DEFF Research Database (Denmark)

    Brinkman, C. R.; Rittenhouse, P. L.; Corwin, W.R.

    1976-01-01

    Hastelloy X, an Ni--Cr--Fe--Mo alloy, may be an important structural alloy for components of gas-cooled reactor systems. Expected applications of this alloy in the High-Temperature Gas-Cooled Reactor (HTGR) are discussed, and the development of interim mechanical properties and supporting data...

  11. Study on secondary shutdown systems in Tehran research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jalali, H.R.; Fadaei, A.H., E-mail: Fadaei_amir@aut.ac.ir; Gharib, M.

    2015-09-15

    Highlights: • A study was undertaken to summarize the techniques for secondary shutdown systems (SSS). • Neutronic calculation performed for proposed systems as SSS. • Dumping the heavy water stored in the reflector vessel is capable to shut down reactor. • Neutronic and transient calculation was done for validating the selected SSS. • All calculation shown that this system has advantages in safety and neutron economy. - Abstract: One important safety aspect of any research reactor is the ability to shut down the reactor. Usually, research reactors, currently in operation, have a single shutdown system based on the simultaneous insertion of the all control rods into the reactor core through gravity. Nevertheless, the International Atomic Energy Agency currently recommends use of two shutdown systems which are fully independent from each other to guarantee secure shutdown when one of them fails. This work presents an investigative study into secondary shutdown systems, which will be an important safety component in the research reactor and will provide another alternative way to shut down the reactor emergently. As part of this project, a study was undertaken to summarize the techniques that are currently used at world-wide research reactors for recognizing available techniques to consider in research reactors. Removal of the reflector, removal of the fuels, change in critical shape of reactor core and insertion of neutron absorber between the core and reflector are selected as possible techniques in mentioned function. In the next step, a comparison is performed for these methods from neutronic aspects. Then, chosen method is studied from the transient behavior point of view. Tehran research reactor which is a 5 MW open-pool reactor selected as a case study and all calculations are carried out for it. It has 5 control rods which serve the purpose of both reactivity control and shutdown of reactor under abnormal condition. Results indicated that heavy

  12. Roles of microorganisms other than Clostridium and Enterobacter in anaerobic fermentative biohydrogen production systems--a review.

    Science.gov (United States)

    Hung, Chun-Hsiung; Chang, Yi-Tang; Chang, Yu-Jie

    2011-09-01

    Anaerobic fermentative biohydrogen production, the conversion of organic substances especially from organic wastes to hydrogen gas, has become a viable and promising means of producing sustainable energy. Successful biological hydrogen production depends on the overall performance (results of interactions) of bacterial communities, i.e., mixed cultures in reactors. Mixed cultures might provide useful combinations of metabolic pathways for the processing of complex waste material ingredients, thereby supporting the more efficient decomposition and hydrogenation of biomass than pure bacteria species would. Therefore, understanding the relationships between variations in microbial composition and hydrogen production efficiency is the first step in constructing more efficient hydrogen-producing consortia, especially when complex and non-sterilized organic wastes are used as feeding substrates. In this review, we describe recent discoveries on bacterial community composition obtained from dark fermentation biohydrogen production systems, with emphasis on the possible roles of microorganisms that co-exist with common hydrogen producers.

  13. Coupling System for Food Wastes Anaerobic Digestion and Polyhydroxyalkanoates Production with Ralstonia eutropha

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new technology was developed to couple the anaerobic digestion of food wastes with production of polyhydroxyalkanoates (PHAs). Acetic, propionic, butyric and lactic acids were produced during food wastes anaerobic digestion and their concentrations reached 5.5, 1.8, 27.4 and 32.7 g/L, respectively under appropriate digestion conditions. The fermentative acids were transferred through a dialysis membrane to an air-lift reactor for PHA synthesis by Ralstonia eutropha. Dry cell concentration and PHA content reached 22.7 g/L and 72.6%, respectively. The obtained PHA was a copolymer of (-hydroxybutyrate (HB) and (-hydroxyvalerate (HV) with 2.8% (mole ratio) of HV units in polymer.

  14. COD removal and biogas production at the manipueira treatment in anaerobic one-stage reactor with different supporting media; Remocao de DQO e producao de biogas no tratamento de manipueira em reator anaerobico monofasico com diferentes meios de suporte

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Douglas Guedes Batista; Kunzler, Kathia Regina; Gomes, Simone Damasceno; Tavares, Maria Herminia Ferreira; Assis, Tatiane Martins de [Universidade Estadual do Oeste do Parana (UNIOESTE), PR (Brazil)], Emails: simoned@unioeste.br, mhstavar@certto.com.br

    2009-07-01

    This study aims at evaluating the efficiency for organic load removal and biogas production for the manipueira treatment in two anaerobic reactors using as supporting media bamboo rings and polyurethane. The manipueira loads added to the systems were 0.548, 1.156, 1.471 and 3.049 g COD/ L{sub reactorday}, gradually increased. With bamboo as supporting media, the load increasing carried the greatest biogas production, with 3.049 g COD/ L{sub reactorday}. Using polyurethane, the greatest production occurred with the 1.471 g CODL{sub reactorday} {sup -1}load. Therefore, it was shown that the supporting media use allowed greater loads and biogas productions, comparatively to the literature data. (author)

  15. The Effect of Enzyme Addition on Anaerobic Digestion of Jose Tall Wheat Grass

    Science.gov (United States)

    The effects of the addition of enzyme products containing cellulase, hemicellulase, and Beta-glucosidase to anaerobic digestion systems were studied. Anaerobic digestion tests were performed using batch reactors operated at 35°C. The application of enzyme products in three digestion configurations w...

  16. Improved dechlorinating performance of upflow anaerobic sludge blanket reactors by incorporation of Dehalospirillum multivorans into granular sludge

    DEFF Research Database (Denmark)

    Hörber, Christine; Christiansen, Nina; Arvin, Erik

    1998-01-01

    was compared to the reference 1 (R1) reactor, where the granules were autoclaved to remove all dechlorinating abilities before inoculation, and to the reference 2 (R2) reactor, containing only living granular sludge. All three reactors were fed mineral medium containing 3 to 57 mu M PCE, 2 mM formate, and 0...... to DCE, even at HRTs much lower than the reciprocal maximum specific growth rate of D. multivorans, indicating that this bacterium was immobilized in the living and autoclaved granular sludge. In contrast, the R2 reactor, with no inoculation of D. multivorans, only converted PCE to TCE under the same...

  17. Development of antibiotic resistance genes in microbial communities during long-term operation of anaerobic reactors in the treatment of pharmaceutical wastewater.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2015-10-15

    Biological treatment processes offer the ideal conditions in which a high diversity of microorganisms can grow and develop. The wastewater produced during these processes is contaminated with antibiotics and, as such, they provide the ideal setting for the acquisition and proliferation of antibiotic resistance genes (ARGs). This research investigated the occurrence and variation in the ARGs found during the one-year operation of the anaerobic sequencing batch reactors (SBRs) used to treat pharmaceutical wastewater that contained combinations of sulfamethoxazole-tetracycline-erythromycin (STE) and sulfamethoxazole-tetracycline (ST). The existence of eighteen ARGs encoding resistance to sulfamethoxazole (sul1, sul2, sul3), erythromycin (ermA, ermF, ermB, msrA, ereA), tetracycline (tetA, tetB, tetC, tetD, tetE, tetM, tetS, tetQ, tetW, tetX) and class Ι integron gene (intΙ 1) in the STE and ST reactors was investigated by quantitative real-time PCR. Due to the limited availability of primers to detect ARGs, Illumina sequencing was also performed on the sludge and effluent of the STE and ST reactors. Although there was good reactor performance in the SBRs, which corresponds to min 80% COD removal efficiency, tetA, tetB, sul1, sul2 and ermB genes were among those ARGs detected in the effluent from STE and ST reactors. A comparison of the ARGs acquired from the STE and ST reactors revealed that the effluent from the STE reactor had a higher number of ARGs than that from the ST reactor; this could be due to the synergistic effects of erythromycin. According to the expression of genes results, microorganisms achieve tetracycline and erythromycin resistance through a combination of three mechanisms: efflux pumping protein, modification of the antibiotic target and modifying enzymes. There was also a significant association between the presence of the class 1 integron and sulfamethoxazole resistance genes.

  18. Materials degradation in fission reactors: Lessons learned of relevance to fusion reactor systems

    Science.gov (United States)

    Was, Gary S.

    2007-08-01

    The management of materials in power reactor systems has become a critically important activity in assuring the safe, reliable and economical operation of these facilities. Over the years, the commercial nuclear power reactor industry has faced numerous 'surprises' and unexpected occurrences in materials. Mitigation strategies have sometimes solved one problem at the expense of creating another. Other problems have been solved successfully and have motivated the development of techniques to foresee problems before they occur. This paper focuses on three aspects of fission reactor experience that may benefit future fusion systems. The first is identification of parameters and processes that have had a large impact on the behavior of materials in fission systems such as temperature, dose rate, surface condition, gradients, metallurgical variability and effects of the environment. The second is the development of materials performance and failure models to provide a basis for assuring component integrity. Last is the development of proactive materials management programs that identify and pre-empt degradation processes before they can become problems. These aspects of LWR experience along with the growing experience with materials in the more demanding advanced fission reactor systems form the basis for a set of 'lessons learned' to aid in the successful management of materials in fusion reactor systems.

  19. Aerobic vs anaerobic exercise training effects on the cardiovascular system.

    Science.gov (United States)

    Patel, Harsh; Alkhawam, Hassan; Madanieh, Raef; Shah, Niel; Kosmas, Constantine E; Vittorio, Timothy J

    2017-02-26

    Physical exercise is one of the most effective methods to help prevent cardiovascular (CV) disease and to promote CV health. Aerobic and anaerobic exercises are two types of exercise that differ based on the intensity, interval and types of muscle fibers incorporated. In this article, we aim to further elaborate on these two categories of physical exercise and to help decipher which provides the most effective means of promoting CV health.

  20. Aerobic vs anaerobic exercise training effects on the cardiovascular system

    Science.gov (United States)

    Patel, Harsh; Alkhawam, Hassan; Madanieh, Raef; Shah, Niel; Kosmas, Constantine E; Vittorio, Timothy J

    2017-01-01

    Physical exercise is one of the most effective methods to help prevent cardiovascular (CV) disease and to promote CV health. Aerobic and anaerobic exercises are two types of exercise that differ based on the intensity, interval and types of muscle fibers incorporated. In this article, we aim to further elaborate on these two categories of physical exercise and to help decipher which provides the most effective means of promoting CV health. PMID:28289526

  1. Remoção de matéria orgânica, de nutrientes e de coliformes no processo anaeróbio em dois estágios (reator compartimentado seguido de reator UASB para o tratamento de águas residuárias de suinocultura Organic matter, nutrients and coliforms removal in two-stage anaerobic process (anaerobic baffled reactor followed by UASB reactor for swine wastewater treatment

    Directory of Open Access Journals (Sweden)

    Mário S. de Abreu Neto

    2009-03-01

    5.4 h in the UASB reactor. The mean CODtotal removal efficiency varied from 69 to 84% in the ABR reactor and from 39 to 58% in the UASB reactor, resulting in average values ranging from 87 to 94% for the two-stage anaerobic treatment system under organic loading rate (OLR of 11.5 to 18.0 g total COD (L d-1 in the ABR reactor and 4.2 to 13.4 g total COD (L d -1 in the UASB reactor. The maximum volumetric methane production of 0.227 m³ CH4 (m³ reactor d-1 occurred in the UASB reactor with OLR of 10.6 g total COD (L d-1 and HDT of 5.4 h. The most removal efficiencies of thermotolerant coliforms (99.7, diss COD (94%, TSS (96%, NTK (71%, P-total (61% and other minerals in the two-stage anaerobic treatment system was obtained with HDT of 73.6 h and medium air temperature of 24.6 °C, applying the minor OLR of 11.5 g total COD (L d -1 in the ABR reactor and 4.2 g total COD (L d-1 in the UASB reactor with the biggest affluent TSS (13.001 mg L-1.

  2. Effect of hydraulic retention time on up-flow anaerobic stage reactor performance at constant loading in the presence of antibiotic tylosin

    Directory of Open Access Journals (Sweden)

    S. Chelliapan

    2011-03-01

    Full Text Available The present investigation was aimed at determining the impact of the macrolide antibiotic Tylosin in reduced HRT at constant organic loading rate (OLR by varying feed substrate concentration in an up-flow anaerobic stage reactor (UASR. The antibiotic concentration was maintained at 200 mg.L-1, at constant OLR of 1.88 kg COD.m-3.d-1, by varying feed substrate concentration to the UASR and the HRT was decreased gradually from 4 to 1 d. Throughout the operation period, brewery wastewater was used as simple feed substrate to elevate the concentration of easily biodegradable carbon in comparison with the concentrations of more recalcitrant Tylosin substrate. The reactor alkalinity was controlled in all the stages of UASR by adding 1000 - 2000 mg.L-1 CaCO3. Results showed the total COD removal efficiency at 4 d HRT was around 92%, after which point there was a slight decrease at 3 and 2 d HRT (average 82%, and this was reduced further (average 77% at a HRT of 1 d. The UASR showed stable operation with effluent volatile fatty acid (VFA less than 300 mg.L-1 throughout the experimental period (HRT 4 - 1 d. Moreover, the average methane yield (CH4.kg CODr-1 showed a relatively constant profile and was largely unaffected by HRT in all the stages of UASR. These results show that bacteria were readily adapted to wastewater containing Tylosin at lower HRTs and did not affect the reactor performance substantially.

  3. Back propagation neural network modelling of biodegradation and fermentative biohydrogen production using distillery wastewater in a hybrid upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Sridevi, K; Sivaraman, E; Mullai, P

    2014-08-01

    In a hybrid upflow anaerobic sludge blanket (HUASB) reactor, biodegradation in association with biohydrogen production was studied using distillery wastewater as substrate. The experiments were carried out at ambient temperature (34±1°C) and acidophilic pH of 6.5 with constant hydraulic retention time (HRT) of 24h at various organic loading rates (OLRs) (1-10.2kgCODm(-3)d(-1)) in continuous mode. A maximum hydrogen production rate of 1300mLd(-1) was achieved. A back propagation neural network (BPNN) model with network topology of 4-20-1 using Levenberg-Marquardt (LM) algorithm was developed and validated. A total of 231 data points were studied to examine the performance of the HUASB reactor in acclimatisation and operation phase. The statistical qualities of BPNN models were significant due to the high correlation coefficient, R(2), and lower mean absolute error (MAE) between experimental and simulated data. From the results, it was concluded that BPNN modelling could be applied in HUASB reactor for predicting the biodegradation and biohydrogen production using distillery wastewater.

  4. Organic loading rate and food-to-microorganism ratio shape prokaryotic diversity in a demo-scale up-flow anaerobic sludge blanket reactor treating domestic wastewater.

    Science.gov (United States)

    Cardinali-Rezende, Juliana; Araújo, Juliana C; Almeida, Paulo G S; Chernicharo, Carlos A L; Sanz, José L; Chartone-Souza, Edmar; Nascimento, Andréa M A

    2013-12-01

    We investigated the microbial community in an up-flow anaerobic sludge blanket (UASB) reactor treating domestic wastewater (DW) during two different periods of organic loading rate (OLR) and food-to-microorganism (F/M) ratio. 16S rDNA clone libraries were generated, and quantitative real-time PCR (qPCR) analyses were performed. Fluctuations in the OLR and F/M ratio affected the abundance and the composition of the UASB prokaryotic community, mainly at the species level, as well as the performance of the UASB reactor. The qPCR analysis suggested that there was a decrease in the bacterial cell number during the rainy season, when the OLR and F/M ratio were lower. However, the bacterial diversity was higher during this time, suggesting that the community degraded more diversified substrates. The diversity and the abundance of the archaeal community were higher when the F/M ratio was lower. Shifts in the methanogenic community composition might have influenced the route of methane production, with methane produced by acetotrophic methanogens (dry season), and by hydrogenotrophic, methylotrophic and acetotrophic methanogens (rainy season). This study revealed higher levels of bacterial diversity, metabolic specialization and chemical oxygen demand removal efficiency of the DW UASB reactor during the rainy season.

  5. Biogenic hydrogen conversion of de-oiled jatropha waste via anaerobic sequencing batch reactor operation: process performance, microbial insights, and CO2 reduction efficiency.

    Science.gov (United States)

    Kumar, Gopalakrishnan; Lin, Chiu-Yue

    2014-01-01

    We report the semicontinuous, direct (anaerobic sequencing batch reactor operation) hydrogen fermentation of de-oiled jatropha waste (DJW). The effect of hydraulic retention time (HRT) was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L ∗ d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d) with a DJW concentration of 200 g/L, temperature 55 °C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L ∗ d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30 °C, and pH 7.0. PCR-DGGE analysis revealed that combination of cellulolytic and fermentative bacteria were present in the hydrogen producing ASBR.

  6. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Kumar

    2014-01-01

    Full Text Available We report the semicontinuous, direct (anaerobic sequencing batch reactor operation hydrogen fermentation of de-oiled jatropha waste (DJW. The effect of hydraulic retention time (HRT was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L*d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L*d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR.

  7. Slaughterhouse wastewater treatment: evaluation of a new three-phase separation system in a UASB reactor.

    Science.gov (United States)

    Caixeta, Cláudia E T; Cammarota, Magali C; Xavier, Alcina M F

    2002-01-01

    The anaerobic treatment of the wastewater from the meat processing industry was studied using a 7.2 1 UASB reactor. The reactor was equipped with an unconventional configuration of the three-phase separation system. The effluent was characterized in terms of pH (6.3-6.6), chemical oxygen demand (COD) (2,000-6,000 mg l(-1)), biochemical oxygen demand BOD5 (1,300-2,300 mg 1(-1)), fats (40-600 mg l(-1)) and total suspended solids (TSS) (850-6,300 mg l(-1)) The reactor operated continuously throughout 80 days with hydraulic retention time of 14, 18 and 22 h. The wastewater from Rezende Industrial was collected after it had gone through pretreatment (screening, flotation and equalization). COD, BOD and TSS reductions and the biogas production rate were the parameters considered in analyzing the efficiency of the process. The average production of biogas was 111 day(-1) (STP) for the three experimental runs. COD removal varied from 77% to 91% while BOD removal was 95%. The removal of total suspended solids varied from 81% to 86%. This fact supports optimal efficiency of the proposed three-phase separation system as well as the possibility of applying it to the treatment of industrial effluents.

  8. Hydrogen production in anaerobic reactors during shock loads--influence of formate production and H2 kinetics.

    Science.gov (United States)

    Voolapalli, R K; Stuckey, D C

    2001-05-01

    In this article the role of hydrogen as a process monitoring tool in methanogenic systems was studied by considering the influence of several key system parameters. Hydrogen production was found to be influenced mainly by the inocula's source pH, and varied only slightly with external pH and HCO3- levels. When an inoculum adapted to above neutral conditions (pH > 7) was shocked, reducing equivalents were selectively channelled through formate, while high hydrogen production was noticed with acidically (pH production of hydrogen or formate during shock loads was not strongly associated with microbial morphology (granules or flocs) as high electron fluxes were possible through either during acidogenesis. Shock load experiments in continuous reactors revealed that neither hydrogen nor formate accumulated to any significant degree, nevertheless digester recovery took a long time due to the slow kinetics of volatile fatty acid degradation. Selective formate production under neutral pH environments, coupled with high hydrogenotrophic activity, was found to be responsible for the dampened hydrogen response during the early phases of gradually shocked systems (step change). Based on these results it appears that the role of hydrogen as a process monitoring tool has been overemphasised in the literature.

  9. Microprocessor tester for the treat upgrade reactor trip system

    Energy Technology Data Exchange (ETDEWEB)

    Lenkszus, F.R.; Bucher, R.G.

    1984-01-01

    The upgrading of the Transient Reactor Test (TREAT) Facility at ANL-Idaho has been designed to provide additional experimental capabilities for the study of core disruptive accident (CDA) phenomena. In addition, a programmable Automated Reactor Control System (ARCS) will permit high-power transients up to 11,000 MW having a controlled reactor period of from 15 to 0.1 sec. These modifications to the core neutronics will improve simulation of LMFBR accident conditions. Finally, a sophisticated, multiply-redundant safety system, the Reactor Trip System (RTS), will provide safe operation for both steady state and transient production operating modes. To insure that this complex safety system is functioning properly, a Dedicated Microprocessor Tester (DMT) has been implemented to perform a thorough checkout of the RTS prior to all TREAT operations.

  10. Kinetic analysis of phenol, thiocyanate and ammonia-nitrogen removals in an anaerobic-anoxic-aerobic moving bed bioreactor system

    Energy Technology Data Exchange (ETDEWEB)

    Sahariah, Biju Prava [Centre for the Environment, Indian Institute of Technology Guwahati, Assam 781039 (India); Chakraborty, Saswati, E-mail: chakraborty_saswati@hotmail.com [Department of Civil Engineering, Indian Institute of Technology Guwahati, Assam 781039 (India)

    2011-06-15

    A simulated wastewater containing phenol (2500 mg/L), thiocyanate and ammonia-nitrogen (500 mg/L) was treated in an anaerobic (R1)-anoxic (R2)-aerobic (R3) moving bed biofilm reactor system at different hydraulic retention time (HRT) intervals (total HRT 3-8 days, R1: 1.5-4 days; R2: 0.75-2 days and R3: 0.75-2 days) and feed thiocyanate (SCN{sup -}) concentrations (110-600 mg/L) to determine substrate removal kinetics. In R1, phenol and COD reduction and specific methanogenic activity were inhibited due to the increase of SCN{sup -} in feed. Bhatia et al. model having inbuilt provision of process inhibition described the kinetics of COD and phenol utilization with maximum utilization rates of 0.398 day{sup -1} and 0.486 day{sup -1}, respectively. In R2 and R3 modified Stover-Kincannon model was suitable to describe substrate utilization. In R2 respective maximum SCN{sup -}, phenol, COD and NO{sub 3}{sup -}N utilization rates were 0.23, 5.28, 37.7 and 11.82 g/L day, respectively. In aerobic reactor R3, COD, SCN{sup -} and NH{sub 4}{sup +}-N removal rates were, respectively, 10.53, 1.89, and 2.17 g/L day. The minimum total HRT of three-stage system was recommended as 4 days.

  11. Army Gas-Cooled Reactor Systems Program. Operation of ML-1 reactor skid in GCRE: safety evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1964-10-01

    The operation of the ML-1 reactor skid in the modified GCRE facility, utilizing the GCRE reactor coolant circulating and heat removal systems, is described. An evaluation of the safety considerations associated with this mode of operation indicates that the consequences of the maximum credible accident are less severe than those previously approved for operation of the ML-1 reactor at the ML-1 test site or for operation of the GCRE-I reactor in the GCRE facility.

  12. Modelling hydraulic transport and anaerobic uptake by PAOs and GAOs during wastewater feeding in EBPR granular sludge reactors.

    Science.gov (United States)

    Weissbrodt, David G; Holliger, Christof; Morgenroth, Eberhard

    2017-03-21

    New-generation bioprocesses using granular sludge aim for a high-rate removal of nutrients from wastewater with low footprint. Achieving enhanced biological phosphorus removal (EBPR) relies on the design of sludge beds and wastewater feeding conditions to optimally load the biomass and to select for polyphosphate- (PAOs) over glycogen-accumulating organisms (GAOs) and other heterotrophs. A hydraulic-metabolic mathematical model was developed to elucidate the impact of hydraulic transport patterns and environmental conditions on the PAO/GAO competition during up-flow feeding through an EBPR granular sludge bed. Tracer experiments highlighted plug-flow regimes with dispersion under both rapid (9 m h(-1) , Rebed  = 1.6, Pez  = 7.2, Pet  = 4.6) and slow (0.9 m h(-1) , Rebed  = 0.2, Pez  = 21.3, Pet  = 3.4) feeding. Non-turbulent regimes (Rebed Feeding time, pH, and temperature significantly impacted bacterial competition for carbon uptake under anaerobic slow feeding. Feeding duration should be designed to avoid full depletion of intracellular storage polymers within static granules. PAOs bear twice longer feeding than GAOs by using both polyphosphate and glycogen hydrolysis to sustain anaerobic C-uptake. Alkaline conditions (pH 7.25-8.0) by, e.g., dosing lime in the feed select for PAOs independently of temperature (10 - 30°C). A twice higher bed is required for full anaerobic conversions at 10 rather than 20 °C. Biosystem responses for anaerobic C-uptake can be anticipated using the model toward designing robust anaerobic selectors to manage the microbial resource in EBPR granular sludge. This article is protected by copyright. All rights reserved.

  13. Passive Decay Heat Removal System for Micro Modular Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jangsik; Lee, Jeong Ik; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    Dry cooling system is applied as waste heat removal system therefore it is able to consider wide construction site. Schematic figure of the reactor is shown in Fig. 1. In safety features, the reactor has double containment and passive decay heat removal (PDHR) system. The double containment prevents leakage from reactor coolant system to be emitted into environment. The passive decay heat removal system copes with design basis accidents (DBAs). Micros Modular Reactor (MMR) which has been being developed in KAIST is S-CO{sub 2} gas cooled reactor and shows many advantages. The S-CO{sub 2} power cycle reduces size of compressor, and it makes small size of power plant enough to be transported by trailer.The passive residual heat removal system is designed and thermal hydraulic (TH) analysis on coolant system is accomplished. In this research, the design process and TH analysis results are presented. PDHR system is designed for MMR and coolant system with the PDHR system is analyzed by MARS-KS code. Conservative assumptions are applied and the results show that PDHR system keeps coolant system under the design limitation.

  14. Effects of hydraulic retention time (HRT) and sludge retention time (SRT) on the treatment of nitrobenzene in AMBR/CSTR reactor systems.

    Science.gov (United States)

    Kuscu, O S; Sponza, D T

    2007-03-01

    The effect of hydraulic retention time (HRT) and solid retention time (SRT) on the biodegradation of a synthetic wastewater containing nitrobenzene was investigated in a sequential anaerobic migrating blanket reactor (AMBR) and aerobic completely stirred tank reactor (CSTR) system. Reactor performance was evaluated at six different HRTs (1,1.5,2,2.5,3.5,5.19 and 10.38 days) and at six different SRTs (32,53,76,217,415 and 932 days). The influent COD and nitrobenzene concentration were kept constant at 3000 mg l(-1) and 60 mg l(-1), respectively, during continuous operation. The maximum COD removal efficiency was found to be 92% at a HRT of 10.38 days and a SRT of 932 days in AMBR reactor. However, nitrobenzene removal efficiencies were found to be 99.9% through all HRTs and SRTs in AMBR reactor. Most of the influent COD and nitrobenzene concentrations were removed in first compartment of AMBR. The total and methane gas production rates increased from 2760 ml day(-1) to 11760 ml day(-1) and from 1300 ml day(-1) to 3331 ml day(-1), respectively, as the HRT was decreased from 10.38 to 1 day in AMBR. However, methane percentage decreased from 47% to 28% with decreased HRTs and SRTs. The methanogens inhibition was observed at lower HRTs. pH values in the compartments and the effluent of AMBR was between optimum values. TVFA concentrations in effluent of AMBR were measured as zero until a HRT of 3.5 days. In the aerobic CSTR reactor, the COD removal efficiency decreased from 79% to 68% with decreased HRT from 6.79 to 0.67 days. It was found that the nitrobenzene transformed to aniline under anaerobic phase, and then the aniline mineralized in the oxidative stage, with efficiencies varying between 79% to 99.9%, in anaerobic/aerobic reactor system.

  15. Autonomous Control of Space Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Belle R. Upadhyaya; K. Zhao; S.R.P. Perillo; Xiaojia Xu; M.G. Na

    2007-11-30

    Autonomous and semi-autonomous control is a key element of space reactor design in order to meet the mission requirements of safety, reliability, survivability, and life expectancy. Interrestrial nuclear power plants, human operators are avilable to perform intelligent control functions that are necessary for both normal and abnormal operational conditions.

  16. Intermittent vs continuous operation of upflow anaerobic sludge bed reactors for dairy wastewater and related microbial changes.

    Science.gov (United States)

    Nadais, H; Capela, I; Arroja, L

    2006-01-01

    This work compares continuous vs intermittent UASB reactors inoculated with flocculent sludge for the treatment of dairy effluents. The effects of effluent recirculation on the performance of intermittent reactors were assessed as well as the differences in specific methanogenic activity (SMA) with different substrates for the biomass from continuous and intermittent UASB reactors. Compared to the continuous operation the intermittent operation resulted in higher methanization of the removed COD (64-78% and 65-88%, respectively) whilst the effluent recirculation presented beneficial effects when applied during the stabilization period and was clearly detrimental when applied during the feed period of the intermittent operation. The SMA tests showed that the intermittent operation causes a shift in the microbial populations towards a better adaptation for the degradation of complex substrates confirmed by the meaningfull contribution of methane production through a pathway other than acetoclastic methanogenesis observed in the biomass taken from intermittent UASB reactors.

  17. 厌氧/缺氧SBR反硝化除磷过程的研究%Denitrification and Dephosphatation by Anaerobic/Anoxic Sequencing Batch Reactor

    Institute of Scientific and Technical Information of China (English)

    彭永臻; 李勇智; 王淑莹; 王亚宜

    2004-01-01

    Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than 1 mg·L-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg· L-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus removal decreased with 8 days SRT. When the SRT was restored to 16 days, however, the efficiency of phosphorus removal was higher than 90%.

  18. Ecology of SRB in anaerobic biotreatment reactor%厌氧处理构筑物中SRB的生态学

    Institute of Scientific and Technical Information of China (English)

    任南琪; 王爱杰; 甄卫东

    2001-01-01

    对处理硫酸盐废水过程中,硫酸盐还原菌(SRB)在处理构筑物中的生态学研究进行了综述。着重论述了影响SRB代谢的重要生态因子包括pH值、温度、底物资源、抑制剂等),SRB与MPB和AB对H2和乙酸、VFA等共同底物的竞争利用,并介绍了不同SRB种群对底物的竞争,指出对SRB生态学研究的深入和完善可使硫酸盐废水的处理水平和技术不断提高。%Sums up the ecology of sulfate-reducing-bacteriaSRB in anaerobic biotreatment reactor which includes 9 genus and over 100 species detected and widely distributed in the anaerobic treatment set and depends on its biological diversity and nourishment variety describes the important ecological factors having effect on the behavior of SRB such as pH temperature substrate inhibitor intermediate metabolite the competition for cosubstrate such as H2 VFA acetate and the competition for acetate between SRB and MPB in particular which is affected by temperature immobilization of bacteria concentration of sulfate and the acclimation of sludge and the competition for substrate between different SRB population as well.

  19. Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Shropshire

    2009-01-01

    The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program’s understanding of the cost drivers that will determine nuclear power’s cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-iradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

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

    OpenAIRE

    Roest, C.

    2007-01-01

    The need for clean water is increasing and anaerobic wastewater treatment can be used as a cost-effective solution for purification of organically polluted industrial waste streams. This thesis presents results from microbiological investigations of several full-scale and lab-scale anaerobic wastewater treatments systems. Anaerobic wastewater treatment has gained popularity and is now one of the key technologies in environmental biotechnology. However, knowledge of the microbial community str...

  1. Model Based Cyber Security Analysis for Research Reactor Protection System

    Energy Technology Data Exchange (ETDEWEB)

    Sho, Jinsoo; Rahman, Khalil Ur; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Son, Hanseong [Joongbu Univ., Geumsan (Korea, Republic of)

    2013-07-01

    The study on the qualitative risk due to cyber-attacks into research reactors was performed using bayesian Network (BN). This was motivated to solve the issues of cyber security raised due to digitalization of instrumentation and control (I and C) system. As a demonstrative example, we chose the reactor protection system (RPS) of research reactors. Two scenarios of cyber-attacks on RPS were analyzed to develop mitigation measures against vulnerabilities. The one is the 'insertion of reactor trip' and the other is the 'scram halt'. The six mitigation measures are developed for five vulnerability for these scenarios by getting the risk information from BN.

  2. New reactor technology: safety improvements in nuclear power systems.

    Science.gov (United States)

    Corradini, M L

    2007-11-01

    Almost 450 nuclear power plants are currently operating throughout the world and supplying about 17% of the world's electricity. These plants perform safely, reliably, and have no free-release of byproducts to the environment. Given the current rate of growth in electricity demand and the ever growing concerns for the environment, nuclear power can only satisfy the need for electricity and other energy-intensive products if it can demonstrate (1) enhanced safety and system reliability, (2) minimal environmental impact via sustainable system designs, and (3) competitive economics. The U.S. Department of Energy with the international community has begun research on the next generation of nuclear energy systems that can be made available to the market by 2030 or earlier, and that can offer significant advances toward these challenging goals; in particular, six candidate reactor system designs have been identified. These future nuclear power systems will require advances in materials, reactor physics, as well as thermal-hydraulics to realize their full potential. However, all of these designs must demonstrate enhanced safety above and beyond current light water reactor systems if the next generation of nuclear power plants is to grow in number far beyond the current population. This paper reviews the advanced Generation-IV reactor systems and the key safety phenomena that must be considered to guarantee that enhanced safety can be assured in future nuclear reactor systems.

  3. 厌氧发酵反应器一维稳态传热模型的建立与验证%Development and verification of one-dimensional model of steady-state heat transfer for anaerobic fermentation reactor

    Institute of Scientific and Technical Information of China (English)

    刘建禹; 陈泽兴; 李文涛

    2012-01-01

    在北方高寒地区,采取适当的加热及保温措施,确保沼气厌氧发酵所需的稳定温度,是关系到沼气工程冬季能否正常运行的关键所在.厌氧发酵反应器传热耗热量是沼气发酵料液加热系统设计的最基本的数据,它直接影响着加热系统方案的选择、供热管道管径和加热器等主要设备的确定.该文在稳态传热理论的基础上,通过对集厌氧发酵和沼气收集为一体式的全地上反应器传热过程的理论分析,建立了一维稳态传热模型,并通过试验对传热模型进行了修正和验证.结果表明,通过模型计算得到的模拟值与实际值在统计上没有明显差异,传热模型可用于反应器耗热量的计算.这为今后大型沼气工程中厌氧发酵反应器热负荷的计算和反应器能耗的预测提供了依据.%In order to ensure normal operation of the biogas engineering in the alpine regions of northern of China in winter, it is a key factor to keep the stable temperature in the biogas anaerobic fermentation process by means of measurements of proper heating and warming preservation. Thermal consumption of heat transfer in the anaerobic fermentation reactor is the basis for the design of fermentation liquid heating system. It has obvious effect on the selection of heating scheme and determination of major equipments, such as heating system, diameter of heating pipes and heater. Basic on steady state heat transfer theory, a one-dimensional steady heat transfer model was developed by the heat transfer analysis for an integral and overground collection of anaerobic fermentation reactor and methane. This model was modified and validated. The results show that there is no significant difference between the simulation value and the actual value. Therefore, the heat transfer model is feasible for the calculation of thermal consumption of rector. This model can be used for the calculation of heat load and prediction of energy consumption

  4. High organic loading rate on thermophilic hydrogen production and metagenomic study at an anaerobic packed-bed reactor treating a residual liquid stream of a Brazilian biorefinery.

    Science.gov (United States)

    Ferraz Júnior, Antônio Djalma Nunes; Etchebehere, Claudia; Zaiat, Marcelo

    2015-06-01

    This study evaluated the influence of a high organic loading rate (OLR) on thermophilic hydrogen production at an up-flow anaerobic packed-bed reactor (APBR) treating a residual liquid stream of a Brazilian biorefinery. The APBR, filled with low-density polyethylene, was operated at an OLR of 84.2 kg-COD m(-3) d(-1). This value was determined in a previous study. The maximum values of hydrogen production and yield were 5,252.6 mL-H2 d(-1) and 3.7 mol-H2 mol(-1)(total carbohydrates), respectively. However, whereas the OLR remained constant, the specific organic load rate (sOLR) decreased throughout operation from 1.38 to 0.72 g-Total carbohydratesg-VS(-1) h(-1), this decrease negatively affected hydrogen production. A sOLR of 0.98 g-Total carbohydratesg-VS(-1) h(-1) was optimal for hydrogen production. The microbial community was studied using 454-pyrosequencing analysis. Organisms belonging to the genera Caloramator, Clostridium, Megasphaera, Oxobacter, Thermoanaerobacterium, and Thermohydrogenium were detected in samples taken from the reactor at operation days 30 and 60, suggesting that these organisms contribute to hydrogen production.

  5. Anaerobic treatment of pre-hydrolysate liquor (PHL) from a rayon grade pulp mill: pilot and full-scale experience with UASB reactors.

    Science.gov (United States)

    Rao, A Gangagni; Bapat, A N

    2006-12-01

    Pilot studies were carried out for the treatment of pre-hydrolysate liquor (PHL), a high strength effluent (COD: 70,000-80,000 mg/l) emanating from a rayon grade pulp mill using up-flow anaerobic sludge blanket reactor (UASB). Substrate inhibition was avoided with optimum COD feed of around 25,000 mg/l. This was achieved by diluting the PHL with a low strength effluent stream known as alkali back wash (ABW) available in the plant and also by partially recycling the reactor liquid outlet. An optimum organic loading rate (OLR) of 10 could be achieved with a COD reduction of 70-75%, a BOD reduction of 85-90% and a methane yield of 0.31-0.33 m3/kg of COD reduced. The pilot scale studies also revealed that addition of milk of lime (MOL) was essential for neutralization and buffering and DAP and urea to supplement the nutrients in the PHL. Based on the pilot studies, a full-scale high rate biomethanation plant was designed and erected for treating the PHL, which after some modification showed similar performance for COD, BOD reduction and methane yield.

  6. Influence of temperature and pretreatments on the anaerobic digestion of wastewater grown microalgae in a laboratory-scale accumulating-volume reactor.

    Science.gov (United States)

    Kinnunen, Viljami; Craggs, Rupert; Rintala, Jukka

    2014-06-15

    This laboratory-scale study investigated the performance of a low-cost anaerobic digester for microalgae. Low (∼2%) solids content wastewater-grown microalgal biomass (MB) was digested in an unmixed, accumulating-volume reactor (AVR) with solid and liquid separation that enabled a long solids retention time. AVRs (2 or 20 L) were operated at 20 °C, 37 °C or ambient temperature (8-21 °C), and the influence of two pretreatments - low-temperature thermal (50-57 °C) and freeze-thaw - on algal digestion were studied. The highest methane yield from untreated MB was in the 37 °C AVR with 225 L CH4 kg volatile solids (VS)(-1), compared with 180 L CH4 kg VS(-1)added in a conventional, 37 °C completely stirred tank reactor (CSTR), and 101 L CH4 kg VS(-1)added in the 20 °C AVR. Freeze-thaw and low-temperature thermal pretreatments promoted protein hydrolysis and increased methane yields by 32-50% at 20 °C, compared with untreated MB. Pretreatments also increased the mineralisation of nitrogen (41-57%) and phosphorus (76-84%) during digestion. MB digestion at ambient temperature was comparable with digestion at 20 °C, until temperature dropped below 16 °C.

  7. Anaerobic treatment of cassava stillage for hydrogen and methane production in continuously stirred tank reactor (CSTR) under high organic loading rate (OLR)

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Gang; Xie, Li; Zou, Zhonghai; Wang, Wen; Zhou, Qi [Key Laboratory of Yangtze River Water Environment, Ministry of Education (Tongji University), UNEP-Tongji, Tongji University, Siping Road No. 1239, Shanghai 200092 (China); Shim, Hojae [Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078 (China)

    2010-11-15

    Anaerobic hydrogen and methane production from cassava stillage in continuously stirred tank reactor (CSTR) were investigated in this study. Results showed that the heat-pretreatment of inoculum did not enhance hydrogen yield compared to raw inoculum under mesophilic condition after continuous operation. However, the hydrogen yield increased from about 14 ml H{sub 2}/gVS under mesophilic condition to 69.6 ml H{sub 2}/gVS under thermophilic condition due to the decrease of propionate concentration and inhibition of homoacetogens. Therefore, temperature was demonstrated to be more important than pretreatment of inoculum to enhance the hydrogen production. Under high organic loading rate (OLR) (>10 gVS/(L.d)), the two-phase thermophilic CSTR for hydrogen and methane production was stable with hydrogen and methane yields of 56.6 mlH{sub 2}/gVS and 249 mlCH{sub 4}/gVS. The one-phase thermophilic CSTR for methane production failed due to the accumulation of both acetate and propionate, leading to the pH lower than 6. Instead of propionate alone, the accumulations of both acetate and propionate were found to be related to the breakdown of methane reactor. (author)

  8. Analysis of trichloroethylene removal and bacterial community function based on pH-adjusted in an upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Zhang, Ying; Hu, Miao; Li, Pengfei; Wang, Xin; Meng, Qingjuan

    2015-11-01

    The study reported the upflow anaerobic sludge blanket (UASB) reactor performance in treating wastewater containing trichloroethylene (TCE) and characterized variations of bacteria composition and structure by changing the pH from 6.0 to 8.0. A slightly acidic environment (pH < 7.0) had a greater impact on the TCE removal. Illumina pyrosequencing was applied to investigate the bacterial community changes in response to pH shifts. The results demonstrated that pH greatly influenced the dominance and presence of specific populations. The potential TCE degradation pathway in the UASB reactor was proposed. Importantly, the genus Dehalobacter which was capable of reductively dechlorinating TCE was detected, and it was not found at pH of 6.0, which presumably is the reason why the removal efficiency of TCE was the lowest (80.73 %). Through Pearson correlation analyses, the relative abundance of Dehalobacter positively correlated with TCE removal efficiency (R = 0.912). However, the relative abundance of Lactococcus negatively correlated with TCE removal efficiency according to the results from Pearson correlation analyses and redundancy analysis (RDA).

  9. Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina.

    Science.gov (United States)

    Yin, Qi; Zhu, Xiaoyu; Zhan, Guoqiang; Bo, Tao; Yang, Yanfei; Tao, Yong; He, Xiaohong; Li, Daping; Yan, Zhiying

    2016-04-01

    The anaerobic digestion (AD) and microbial electrolysis cell (MEC) coupled system has been proved to be a promising process for biomethane production. In this paper, it was found that by co-cultivating Geobacter with Methanosarcina in an AD-MEC coupled system, methane yield was further increased by 24.1%, achieving to 360.2 mL/g-COD, which was comparable to the theoretical methane yield of an anaerobic digester. With the presence of Geobacter, the maximum chemical oxygen demand (COD) removal rate (216.8 mg COD/(L·hr)) and current density (304.3A/m(3)) were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter, resulting in overall energy efficiency reaching up to 74.6%. Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm, and the electrochemical activities of both were confirmed by cyclic voltammetry. Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter, suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane. Taken together, Geobacter not only can improve the performance of the MEC system, but also can enhance methane production.

  10. Design of virtual SCADA simulation system for pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wijaksono, Umar, E-mail: umar.wijaksono@student.upi.edu; Abdullah, Ade Gafar; Hakim, Dadang Lukman [Electrical Power System Research Group, Department of Electrical Engineering Education, Jl. Dr. Setiabudi No. 207 Bandung, Indonesia 40154 (Indonesia)

    2016-02-08

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles of energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor.

  11. Design of virtual SCADA simulation system for pressurized water reactor

    Science.gov (United States)

    Wijaksono, Umar; Abdullah, Ade Gafar; Hakim, Dadang Lukman

    2016-02-01

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles of energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor.

  12. Small space reactor power systems for unmanned solar system exploration missions

    Energy Technology Data Exchange (ETDEWEB)

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model.

  13. 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.

  14. Anaerobic bioprocessing of sewage sludge, focusing on degradation of linear alkylbenzene sulfonates (LAS)

    Energy Technology Data Exchange (ETDEWEB)

    Angelidaki, I.; Toraeng, L.; Waul, C.M.; Schmidt, J.E.

    2003-07-01

    Anaerobic degradation of sludge amended with linear alkylbenzene sulfonates (LAS) was tested in one stage continuous stirred tank reactor (CSTR) and a two stages reactor system consisting by a CSTR as first step and upflow anaerobic sludge bed (UASB) reactor in the second step. Anaerobic removal of LAS was only observed at the second step but not at the first step. Removal of LAS in the UASB reactors was approx. 80% where half was due to absorption and the other half was apparently due to biological removal as shown from the LAS mass balance. At the end of the experiment the reactors were spiked with {sup 14}C-LAS which resulted in 5.6% {sup 14}CO{sub 2} in the produced gas. Total mass balance of the radioactivity was however not achieved. In batch experiments it was found that LAS at concentrations higher than 50 mg/l is inhibitory for the most microbial groups of the anaerobic process. Therefore, low initial LAS concentration is a prerequisite for successful LAS degradation. The results from the present study suggest that anaerobic degradation of LAS is possible in UASB reactors when the concentration of LAS is low enough to avoid inhibition of microorganisms active in the anaerobic process. (author)

  15. Data acquisition system for segmented reactor antineutrino detector

    Science.gov (United States)

    Hons, Z.; Vlášek, J.

    2017-01-01

    This paper describes the data acquisition system used for data readout from the PMT channels of a segmented detector of reactor antineutrinos with active shielding. Theoretical approach to the data acquisition is described and two possible solutions using QDCs and digitizers are discussed. Also described are the results of the DAQ performance during routine data taking operation of DANSS. DANSS (Detector of the reactor AntiNeutrino based on Solid Scintillator) is a project aiming to measure a spectrum of reactor antineutrinos using inverse beta decay (IBD) in a plastic scintillator. The detector is located close to an industrial nuclear reactor core and is covered by passive and active shielding. It is expected to have about 15000 IBD interactions per day. Light from the detector is sensed by PMT and SiPM.

  16. Reactor technology assessment and selection utilizing systems engineering approach

    Science.gov (United States)

    Zolkaffly, Muhammed Zulfakar; Han, Ki-In

    2014-02-01

    The first Nuclear power plant (NPP) deployment in a country is a complex process that needs to consider technical, economic and financial aspects along with other aspects like public acceptance. Increased interest in the deployment of new NPPs, both among newcomer countries and those with expanding programs, necessitates the selection of reactor technology among commercially available technologies. This paper reviews the Systems Decision Process (SDP) of Systems Engineering and applies it in selecting the most appropriate reactor technology for the deployment in Malaysia. The integrated qualitative and quantitative analyses employed in the SDP are explored to perform reactor technology assessment and to select the most feasible technology whose design has also to comply with the IAEA standard requirements and other relevant requirements that have been established in this study. A quick Malaysian case study result suggests that the country reside with PWR (pressurized water reactor) technologies with more detailed study to be performed in the future for the selection of the most appropriate reactor technology for Malaysia. The demonstrated technology assessment also proposes an alternative method to systematically and quantitatively select the most appropriate reactor technology.

  17. Hybrid Plasma Reactor/Filter for Transportable Collective Protection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Josephson, Gary B.; Tonkyn, Russell G.; Frye, J. G.; Riley, Brian J.; Rappe, Kenneth G.

    2011-04-06

    Pacific Northwest National Laboratory (PNNL) has performed an assessment of a Hybrid Plasma/Filter system as an alternative to conventional methods for collective protecti