WorldWideScience

Sample records for anaerobic baffled reactor

  1. Mathematical Modelling of Cassava Wastewater Treatment Using Anaerobic Baffled Reactor

    OpenAIRE

    A.O. Ibeje

    2013-01-01

    The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater as a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35°C was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000mg L-1. The objective of the study was to formulate an improved mathematical model to describe cassava wastewater treatment without taking into account its inhibition ch...

  2. Investigation of Nitrogen Removal Efficiency from Wastewater using Modified Anaerobic Baffled Reactor (MABR

    Directory of Open Access Journals (Sweden)

    H Ganjidoust

    2010-02-01

    Full Text Available "n "nBackgrounds and Objectives : Nitrogen compounds in wastewater are mainly in four types of organic, am- monia, nitrite and nitrate. Total nitrogen concentration in municipal wastewater is usually within 25 to 45 mg/L as nitrogen. The most important problem with nitrogen is its oxygen demand and human health effect."nMaterials and Methods: Anaerobic Baffled Reactor (ABR is a system in which baffles are used to direct  wastewater flow. During 9 months study, a 15 liter modified ABR (104*30*15 cm with eight baffled com- partments was used for nitrification-denitrification processes. In the seventh compartment, the wastewater was aerated to oxidize ammonia to nitrite and nitrate."nResults : Denitrification was done in the first four compartments with removal efficiency from 60 to 84 per- cent for nitrite and nitrate, respectively. During the shock loading study (4 times of the last influent, a sharp decrease in nitrogen removal rate was observed which was then returned to the previous efficiency after 11 days. Artificial neural network was used to evaluate and process the data in which the observed error in 10 patterns was less than 15 percent."nConclusion : Anaerobic baffled reactor with an influent of up to 200 mg/L has capability to remove total  nitrogen concentration to less than the standard level of Iranian Department of Environment of 50 mg/L as nitrate and 10 mg/L as nitrogen.

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

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. 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.

  6. Modeling the performance of an anaerobic baffled reactor with the variation of hydraulic retention time.

    Science.gov (United States)

    Li, Jianzheng; Shi, En; Antwi, Philip; Leu, Shao-Yuan

    2016-08-01

    Anaerobic baffled reactors (ABRs) have been widely used in engineering but very few models have been developed to simulate its performance. Based on the integration of biomass retention and liquid-gas mass transfer of biogas into the biochemical process derived in the International Water Association (IWA) Anaerobic Digestion Model No.1 (ADM1), a mathematical model was developed to predict volatile fatty acids (VFAs), chemical oxygen demand (CODCr) and biogas in a 4-compartment ABR operated with variable hydraulic retention time (HRT). The model was calibrated and validated with the experimental data obtained from the reactor when the HRT decreased from 2.0 to 1.0d by stages. It was found that the predicted VFAs, CODCr and biogas agreed well with the experimental data. Consequently, the developed model was a reliable tool to enhance the understanding among the mechanisms of the anaerobic digestion in ABRs, as well as to reactor's designing and operation. PMID:27174615

  7. 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.

  8. Pilot scale application of anaerobic baffled reactor for biologically enhanced primary treatment of raw municipal wastewater.

    Science.gov (United States)

    Hahn, Martha J; Figueroa, Linda A

    2015-12-15

    A four-cell anaerobic baffled reactor (ABR) was operated for two years treating raw municipal wastewater at ambient water and air temperatures of 12-23 °C and -10 to 35 °C, respectively. The 1000-L pilot reactor operated at a 12-h hydraulic residence time and was located in the Headworks building of the Plum Creek Water Reclamation Authority. The average influent was TSS = 510 ± 400 mg/L, BOD5 = 320 ± 80 mg/L and the average removal of TSS and BOD5 was 83 ± 10% and 47 ± 15%, respectively. The TSS and BOD removal exceeded that of conventional primary clarification, with no wasting of the settled solids over the two-years and stoichiometric production of methane. The estimated energy content of the biogas produced per unit volume of wastewater treated averaged 0.45 kWh/m(3). The TSS and total COD removal in the first cell averaged 75 ± 15% and 43 ± 14%, respectively, but methane production was only 20% of the total observed for the full ABR. The performance of the ABR relative to the extent of solids hydrolysis and methane production can be varied by the number of cells and hydraulic residence time. The anaerobic baffled reactor is an energy-positive technology that can be used for biologically enhanced primary treatment of raw municipal wastewater in cold climates. PMID:26414605

  9. 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.

  10. Anaerobic wastewater treatment using anaerobic baffled bioreactor: a review

    Science.gov (United States)

    Hassan, Siti; Dahlan, Irvan

    2013-09-01

    Anaerobic wastewater treatment is receiving renewed interest because it offers a means to treat wastewater with lower energy investment. Because the microorganisms involved grow more slowly, such systems require clever design so that the microbes have sufficient time with the substrate to complete treatment without requiring enormous reactor volumes. The anaerobic baffled reactor has inherent advantages over single compartment reactors due to its circulation pattern that approaches a plug flow reactor. The physical configuration of the anaerobic baffled reactor enables significant modifications to be made; resulting in a reactor which is proficient of treating complex wastewaters which presently require only one unit, ultimately significant reducing capital costs. This paper also concerns about mechanism, kinetic and hydrodynamic studies of anaerobic digestion for future application of the anaerobic baffled reactor for wastewater treatment.

  11. 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. PMID:26877027

  12. 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.

  13. Simultaneous denitrification and anaerobic digestion in GRAnular Bed Baffled Reactor (GRABBR)

    International Nuclear Information System (INIS)

    This study elucidates the characteristics of compartmentalised anaerobic system seeded with UASB granules, called GRAanular Bed Baffled Reactor (GRABBR), for combined denitrification and anaerobic digestion processes. The reactor was used for the treatment of glucose enriched synthetic wastewater with various nitrate concentrations. The study was carried out with a 10 litre working volume GRABBR divided into 5 equal compartments operating at organic loading rate (OLR) of 20 kg COD/m3.d with a hydraulic retention time (HRT) of 6 hours. At these conditions, phase separation (between acidogenesis and methanogenesis) was created in the system and then the effect of varying nitrate concentrations (50-200 mg/l NO3-N) in the acidogenic zone (i.e. first compartment) was studied. Due to its unique compartmentalised design, denitrification was the major pathway for nitrate reduction with no noticeable dissimilatory nitrate reduction to ammonia (DNRA). More than 84% of all added nitrates were removed in the acidogenic zone, showing that acidogens possess high denitrifying capabilities. The denitrification rate increased with increase in nitrate concentration, with maximum value estimated as 175 mg NO3-N/l.h at influent nitrate concentration of 200 mg/l NO3-N in the acidogenic zone. Although nitrate addition resulted in lower methane production, COD removal efficiencies improved by up to 8% when compared with the reactor performance before nitrate addition. Furthermore, the alkalinity produced during denitrification improved the stability of the system by controlling the decrease in pH resulting from acidogenesis. The system encouraged simultaneous denitrification and anaerobic digestion in a single unit by accommodating denitrifiers in the early compartments and allowing methanogenesis to flourish in the downstream compartments of the system, thus minimising inhibition to methane producing bacteria by nitrates. (author)

  14. 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%.

  15. Perbandingan Desain IPAL Proses Atached Growth Anaerobic Filter dengan Suspended Grwoth Anaerobic Baffled Reactor untuk Pusat Pertokoan di Kota Surabaya

    Directory of Open Access Journals (Sweden)

    Abdul Hamid

    2014-09-01

    Full Text Available Perencanaan IPAL dilakukan dengan mengidentifikasi karakteristik dan kuantitas limbah dari pusat pertokoan X di Surabaya. Selanjutnya ditetapkan baku mutu dan kriteria desain. Perhitungan desain meliputi dimensi dan rencana anggaran biaya. Dari hasil perhitungan desain didapatkan desain rinci IPAL unit Anaerobic Filter meliputi dimensi bak ekualisasi (2,2 m x 1,1 m x 1,3 m, Bak Pengendap kompartemen I (7 m x 2,5 m x 1,25 kompartemen II (3,5 m x 2,5 m x 1,25 m, AF tiap kompartemen (1,25 m x 0,56 m x 1,25 m sebanyak 6 buah. Desain rinci Unit IPAL Anaerobic Baffled Reactor meliputi dimensi bak ekualisasi (2,2 m x 1,1 m x 1,3 m, Bak Pengendap (8 m x 2 m x 1,5 m, ABR tiap kompartemen (0,75 m x 4 m x 1,5m sebanyak 7 buah. Biaya konstruksi unit AF sebesar Rp 178.383.868,- dan Rp 4.688.912,-/ bulan untuk OM. Sedangkan biaya konstruksi unit ABR Rp 239.247.347,- serta Rp 4.677.801,-/bulan untuk OM.

  16. RESEARCH ADVANCES IN ANAEROBIC BAFFLED REACTOR (ABR)%折流式厌氧反应器(ABR)的研究进展

    Institute of Scientific and Technical Information of China (English)

    王建龙; 韩英健; 钱易

    2000-01-01

    Anaerobic baffled reactor (ABR) is a new high efficient anaerobic treatmen t system. ABR has some advantages over other anaerobic reactors, such as sim ple design,inexpensive to construct,stable to hydraulic and organic shock load ings, and high treatment efficiency. Different types of ABR are described, the study progress and application situation are summarized, and the future development is prospected in this paper. Fig 2, Tab 2, Ref 45

  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. Microbiological studies of an anaerobic baffled reactor: microbial community characterisation and deactivation of health-related indicator bacteria.

    Science.gov (United States)

    Lalbahadur, T; Pillay, S; Rodda, N; Smith, M; Buckley, C; Holder, F; Bux, F; Foxon, K

    2005-01-01

    This WRC funded project has studied the appropriateness of the ABR (anaerobic baffled reactor) for on-site primary sanitation in low-income communities. A 3,000 L pilot reactor was located at the Kingsburgh wastewater treatment plant south of Durban, South Africa. Feed to the reactor was raw domestic wastewater containing a significant proportion of particulate organic matter. The compartments of the ABR were routinely monitored for pH, COD, and gas production, among other physical-chemical determinants. The microbial population in each compartment was analysed by fluorescent in situ hybridisation, using general oligonucleotide probes for eubacteria and archeae and a suite of 10 genera or family specific probes. Scanning electron microscopy was conducted on the sludge fraction of each compartment. Mixed fractions from each compartment were also analysed for health-related indicator bacteria (total coliforms and E. coli). Results indicated that methanogenesis was not occurring to the expected extent in the latter compartments, and that this was probably due to a hydraulic load limitation. This contrasted with earlier studies on industrial effluent, for which the organic load was exclusively in soluble form. Inactivation of health-related indicator bacteria was less than 1 log, indicating the need for an additional post-treatment of the effluent to protect community health. PMID:16104417

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

    International Nuclear Information System (INIS)

    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.

  20. EFFECT OF SULFATE LOADING RATE AND ORGANIC LOADING RATE ON ANAEROBIC BAFFLED REACTORS USED FOR TREATMENT OF SANITARY LANDFILL LEACHATES

    Directory of Open Access Journals (Sweden)

    O. Burbano-Figueroa

    2015-06-01

    Full Text Available AbstractThis study investigated the effect of organic loading rate (OLR and sulfate loading rate (SLR on landfill leachate treatment by a lab-scale anaerobic baffled reactor (ABR. Landfill leachate contained a concentration of organic matter between 3966 and 5090 mg COD.L-1 and no detectable amounts of sulfate. Reactors were started-up by feeding them with iron-sulfate at a SLR of 0.05 g SO42-.L-1.day-1 (4 weeks. Factorial design and response surface techniques were used to evaluate and optimize the effects of these operating variables on COD removal. ABRs were operated at OLRs ranging from 0.30 up to 6.84 g COD.L-1.day-1 by changes in influent volumetric flow. SO42- was added to the influent at a SRL from 0.06 to 0.13 g SO42-.L-1.day-1. The highest value of COD removal (66% was reached at an OLR of 3.58 g COD.L-1.day-1 and SLR of 0.09 g SO4-2.L-1.day-1 with a COD/SO4-2 ratio of 40. Under these conditions sulfate is mainly used for molecular hydrogen consumption while organic matter is preferentially degraded via methanogesis.

  1. Biomethanation of vegetable market waste in an anaerobic baffled reactor: Effect of effluent recirculation and carbon mass balance analysis.

    Science.gov (United States)

    Gulhane, Madhuri; Khardenavis, Anshuman A; Karia, Sneha; Pandit, Prabhakar; Kanade, Gajanan S; Lokhande, Satish; Vaidya, Atul N; Purohit, Hemant J

    2016-09-01

    In the present study, feasibility of biomethanation of vegetable market waste in a 4-chambered anaerobic baffled reactor (ABR) was investigated at 30d hydraulic retention time and organic loading rate of 0.5gVS/L/d for one year. Indicators of process stability viz., butyrate/acetate and propionate/acetate ratios were consistent with phase separation in the different chambers, which remained unaltered even during recirculation of effluent. Chemical oxygen demand (COD) and volatile solids (VS) removal efficiencies were observed to be consistently high (above 90%). Corresponding biogas and methane yields of 0.7-0.8L/g VS added/d and 0.42-52L/g VS added/d respectively were among the highest reported in case of AD of vegetable waste in an ABR. Process efficiency of the ABR for vegetable waste methanation, which is indicated by carbon recovery factor showed that, nearly 96.7% of the input carbon considered for mass balance was accounted for in the product. PMID:27133362

  2. The energy-saving anaerobic baffled reactor membrane bioreactor (EABR-MBR) system for recycling wastewater from a high-rise building.

    Science.gov (United States)

    Ratanatamskul, Chavalit; Charoenphol, Chakraphan

    2015-01-01

    A novel energy-saving anaerobic baffled reactor-membrane bioreactor (EABR-MBR) system has been developed as a compact biological treatment system for reuse of water from a high-rise building. The anaerobic baffled reactor (ABR) compartment had five baffles and served as the anaerobic degradation zone, followed by the aerobic MBR compartment. The total operating hydraulic retention time (HRT) of the EABR-MBR system was 3 hours (2 hours for ABR compartment and very short HRT of 1 hour for aerobic MBR compartment). The wastewater came from the Charoen Wisawakam building. The results showed that treated effluent quality was quite good and highly promising for water reuse purposes. The average flux of the membrane was kept at 30 l/(m2h). The EABR-MBR system could remove chemical oxygen demand, total nitrogen and total phosphorus from building wastewater by more than 90%. Moreover, it was found that phosphorus concentration was rising in the ABR compartment due to the phosphorus release phenomenon, and then the concentration decreased rapidly in the aerobic MBR compartment due to the phosphorus uptake phenomenon. This implies that phosphorus-accumulating organisms inside the EABR-MBR system are responsible for biological phosphorus removal. The research suggests that the EABR-MBR system can be a promising system for water reuse and reclamation for high-rise building application in the near future. PMID:26067504

  3. 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

  4. Perbandingan Desain IPAL Proses Atached Growth Anaerobic Filter dengan Suspended Grwoth Anaerobic Baffled Reactor untuk Pusat Pertokoan di Kota Surabaya

    OpenAIRE

    Abdul Hamid; Mohammad Razif

    2014-01-01

    Perencanaan IPAL dilakukan dengan mengidentifikasi karakteristik dan kuantitas limbah dari pusat pertokoan X di Surabaya. Selanjutnya ditetapkan baku mutu dan kriteria desain. Perhitungan desain meliputi dimensi dan rencana anggaran biaya. Dari hasil perhitungan desain didapatkan desain rinci IPAL unit Anaerobic Filter meliputi dimensi bak ekualisasi (2,2 m x 1,1 m x 1,3 m), Bak Pengendap kompartemen I (7 m x 2,5 m x 1,25) kompartemen II (3,5 m x 2,5 m x 1,25 m), AF tiap kompartemen (1,25 ...

  5. 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.

  6. 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.

  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. Farklı Hidrolik Bekletme Sürelerinin Anaerobik Perdeli Reaktörde Sülfat İndirgenmesi Üzerine Etkisi / Effect of Different Hydraulic Retention Time (HRT on Sulfate Reduction in Anaerobic Baffled Reactor

    Directory of Open Access Journals (Sweden)

    Şebnem ÖZDEMİR

    2012-12-01

    üresinin 2 gün olduğu çalışma koşullarında çıkış suyundaki KOİ ve SO4-2 verimleri %84 ile %88 olarak gözlemlenirken bekleme süresinin 0,5 gün olduğu çalışma koşullarında ise bu değer %80 ve %75 olarak gözlemlenmiştir. Ayrıca bekleme süresinin 2 gün olduğu çalışma koşullarında son bölmedeki sülfür oluşum verimi % 75 iken, bekleme süresi 0,5 güne indirildiğinde aynı bölmedeki sülfür oluşum veriminin %96’a çıktığı gözlemlenmiştir. Çıkarımlar ve Özgün Değer: Yapılan bu çalışma ile yüksek sülfat konsantrasyona sahip atıksuların arıtımında anaerobik perdeli reaktörün iyi bir alternatif olabileceği kanıtlanmıştır. Ayrıca çıkış sülfat ve sülfür konsantrasyonlarının değişen HBS’den etkilenmediği gözlenmiştir. Effect of Different Hydraulic Retention Time (HRT on Sulfate Reduction in Anaerobic Baffled Reactor Design and Method: The anaerobic baffled reactor (ABR is a modification of up-flow anaerobic sludge blanket (UASB reactor. A laboratory scale ABR was inoculated with an effluent of a full scale anaerobic digester located in Kayseri Wastewater Treatment Plant, Turkey. Before inoculation, the sludge was sieved to remove coarse materials. The ABR was 20 cm wide, 80 cm long, 20 cm deep and constructed from glass, with a working volume of 19 L. Reactor was divided into four equal 4.75 L compartments by vertical baffles, each compartment having down-comer and riser regions created by further vertical baffle. The lower parts of down-comer baffles were angled at 450 in order to direct the flow evenly through the riser. Ethanol and sulfate are consumed as electron donor and electron acceptor, respectively. Sulfate, dissolved sulfide, pH, alkalinity and chemical oxygen demand (COD have measured three times a week. Aim: There are varying structures and concentrations of sulfate compounds in natural waters. In addition, the amount of sulfate is higher in some industrial wastewaters In addition, some

  9. Uso de leitos cultivados de fluxo vertical por batelada no pós-tratamento de efluente de reator anaeróbio compartimentado Post-treatment of effluent of anaerobic baffled reactor using batchwise vertical flow constructed wetland beds

    Directory of Open Access Journals (Sweden)

    Marcelo Mazzola

    2005-06-01

    Full Text Available Neste trabalho avaliou-se o desempenho de um Reator Anaeróbio Compartimentado (RAC de duas câmaras em série, seguido de três leitos cultivados (constructed wetlands de fluxo vertical por batelada. A unidade experimental, em escala piloto, foi instalada na Faculdade de Engenharia Agrícola - UNICAMP, Campinas, SP, Brasil. O volume total do reator era de 2,3 m³ (TDH de 12 h. O efluente do RAC foi tratado em três leitos, dois cultivados com macrófitas (gêneros Typha sp. e Eleocharis sp. e um utilizado como controle (não cultivado. Os leitos, com 2,0 m³ cada um e brita #2 (24 - 35 mm como meio suporte, operaram com fluxo vertical por batelada (com tempos de reação de 24, 48, 72 e 96 h. Na avaliação do RAC, observou-se tendência de estabilização dos parâmetros pH, alcalinidade, ácidos voláteis, sólidos sedimentáveis e suspensos totais, porém a remoção de DQO revelou-se limitada (50%. Nos leitos cultivados o aumento do tempo de reação (até 72 h foi acompanhado pelo aumento de remoção de turbidez, DQO, fósforo e nitrato. O melhor desempenho de remoção de fósforo total foi obtido no leito vegetado com Typha sp para os tempos de 72 e 96 h, respectivamente, de 30 e 25%.This study evaluated the performance of vertical constructed wetlands treating effluent of anaerobic baffled reactor. The anaerobic reactor volume was 2.3 m³; it was operated with daily flow of 4.6 m³ (12 hours Hydraulic Retention Time. The reactor effluent was split into three wetlands beds, two of them cultivated with macrophytes (Typha sp. and Eleocharis sp., and one control. The wetlands were operated as a batch reactor. The medium utilized was gravel, the size ranging from 7 to 12 mm. The reaction time for each cycle (filling - reaction - drainage was 24, 48, 72, and 96 h. The anaerobic reactor achieved the following removal rates: settable solids, 93%; suspended solids, 80%; and COD 39%. The increase in reaction time (up to 72 h for the constructed

  10. Valuation and modelling of helminth eggs removal in baffled and unbaffled ponds treating anaerobic effluent.

    Science.gov (United States)

    von Sperling, M; Chernicharo, C A L; Soares, A M E; Zerbini, A M

    2003-01-01

    The paper evaluates and models helminth eggs removal in a combined UASB (Upflow Anaerobic Sludge Blanket) reactor-maturation pond system (one baffled and one unbaffled pond in parallel). The system is comprised of demonstration-scale units, treating actual domestic sewage from Itabira city, Brazil. The paper addresses the following points: (i) removal of helminth eggs from the wastewater in the system; (ii) comparison of the observed removal efficiency with the predictions using the Ayres et al. model; (iii) accumulation of helminth eggs in the sludge; (iv) viability of eggs in the sludge; (v) distribution of helminth species in the sludge. The removal efficiency of helminth eggs from the wastewater in both ponds was 100% for most of the time (0 counts in the final effluent). The predictions of helminth eggs removal according to the Ayres et al. model can be considered reasonable. After one year of operation, 88% of the eggs in the sludge remained viable. Helminth eggs counts in the sludge tended to decrease along the baffled pond length (from first to last compartment). The prevailing helminth species found in the sludge from both ponds was Ascaris lumbricoides. PMID:14510201

  11. Treatment of Molasses Alcohol Wastewater by Anaerobic Baffled Reactor%厌氧折流板反应器处理糖蜜酒精废水的研究

    Institute of Scientific and Technical Information of China (English)

    赵宸艺; 陈源龙; 蒋永荣; 韦添尹

    2012-01-01

    Removal efficiency of anaerobic baffled reactor (ABR) treating molasses alcohol industrial wastewater was investigated, which had succeeded in treating simulated molasses alcohol wastewater. During the experiments of 30 days, chemical oxygen demand (COD) and sulfate (SO4 2-) removal efficiency, volatile fatty acid (VFA).pH and sulfide(S2-) distribution in each compartment were studied. Experimental results showed that under the conditions of the load of COD and SO4 2- as 4.8 kg/(m3·d) and 0.32 kg/(m3·d),the removal efficiency of COD and SO4 2- were 83% and 98% respectively. The change of VFA concentration and pH in each compartment were basically identical. S2- concentration in each compartment was low, and S2- concentrations in Compartment 4 and 5 were less than 40 mg/L. Multi-phase separation characteristics (acidogenic phase and methanogenic phase, sulfate-reducing phase and sulfur-producing phase) that had formed during simulated molasses alcohol wastewater treatment were remained, which would ensure the removal efficiency of ABR treating molasses alcohol industrial wastewater.%为探究厌氧折流板反应器(ABR)对糖蜜酒精实际废水的处理效果,该实验采用已成功处理人工模拟糖蜜酒精废水的ABR,研究了该反应器处理糖蜜酒精工业废水过程中COD和SO42-的去除效果,以及各隔室VFA、pH和S2-的分布规律.实验结果表明,反应器处理糖蜜酒精工业废水,在30d内达到稳定,COD和SO42-负荷分别为4.8 kg/(m3·d)和0.32 kg/(m3 ·d),COD和SO42-的去除率分别为83%和98%.反应器内各隔室挥发性脂肪酸(VFA)浓度变化规律与pH值变化规律一致,各隔室硫化物(S2-)浓度较低,其中第4、5隔室的S2-浓度低于40 mg/L.反应器内微生物菌群仍能保持处理模拟废水时形成的多相(产酸硫酸盐还原相和生成硫单质产甲烷相)分离特征,保证了ABR对实际工业废水的处理效率.

  12. Wastewater treatment in a hybrid activated sludge baffled reactor

    International Nuclear Information System (INIS)

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

  13. 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)

  14. Rapid production of biodiesel in mesoscale oscillatory baffled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Phan, A.N.; Harvey, A.P.; Eze, V. [School of Chemical Engineering and Advanced Materials, Newcastle Upon Tyne (United Kingdom)

    2012-07-15

    Continuous alkali-catalyzed transesterification of rapeseed oil with methanol was carried out in three mesoreactor designs. The induction time decreased with oscillatory Reynolds number for all three reactors. Stable steady states were achieved within induction times of 1.5, 2.5, and 4.0 residence times for the integral, wire wool, and helical baffle designs, respectively. Both experimental and simulated results indicated that under the given conditions there is an optimal residence time for homogeneous transesterification. Higher residence times resulted in reduced fatty acid methyl ester content due to the saponification side reaction. The results demonstrate that biodiesel can be produced at an industrially acceptable level of conversion (> 95 %) in < 5 min residence time. This requires a combination of high catalyst concentration and good mixing. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Biological processing in oscillatory baffled reactors: operation, advantages and potential.

    Science.gov (United States)

    Abbott, M S R; Harvey, A P; Perez, G Valente; Theodorou, M K

    2013-02-01

    The development of efficient and commercially viable bioprocesses is essential for reducing the need for fossil-derived products. Increasingly, pharmaceuticals, fuel, health products and precursor compounds for plastics are being synthesized using bioprocessing routes as opposed to more traditional chemical technologies. Production vessels or reactors are required for synthesis of crude product before downstream processing for extraction and purification. Reactors are operated either in discrete batches or, preferably, continuously in order to reduce waste, cost and energy. This review describes the oscillatory baffled reactor (OBR), which, generally, has a niche application in performing 'long' processes in plug flow conditions, and so should be suitable for various bioprocesses. We report findings to suggest that OBRs could increase reaction rates for specific bioprocesses owing to low shear, good global mixing and enhanced mass transfer compared with conventional reactors. By maintaining geometrical and dynamic conditions, the technology has been proved to be easily scaled up and operated continuously, allowing laboratory-scale results to be easily transferred to industrial-sized processes. This is the first comprehensive review of bioprocessing using OBRs. The barriers facing industrial adoption of the technology are discussed alongside some suggested strategies to overcome these barriers. OBR technology could prove to be a major aid in the development of commercially viable and sustainable bioprocesses, essential for moving towards a greener future. PMID:24427509

  16. Inactivation of Escherichia coli in a baffled pond with attached growth: treating anaerobic effluent under the Sahelian climate.

    Science.gov (United States)

    Moumouni, D A; Andrianisa, H A; Konaté, Y; Ndiaye, A; Maïga, A H

    2016-01-01

    This study aimed to investigate and understand the zero-level detection of Escherichia coli (E. coli) at the outlet of an improved waste stabilization pond. Wastewaters were collected from the International Institute for Water and Environmental Engineering (2iE) campus and were subjected to biological treatment. The system included two-stage Anaerobic Reactors followed by a Baffled Pond (AR-BP) with recycled plastic media as a medium for attached growth and a control pond (CP). Three vertical baffles were installed, giving four compartments in the baffled pond (BP). The research was conducted on the pilot scale from March to July 2014, by monitoring E. coli, pH, temperature, dissolved oxygen (DO) and chlorophyll-a in each compartment and at different depths. The results show that E. coli concentrations were lower in top layers of all compartments with an undetectable level in the last compartment up to 0.60 m deep. E. coli mean removal efficiencies and decay rates were achieved by significant difference in BP (4.5 log-units, 9.1 day(-1)) and CP (1.1 log-units, 1.1 day(-1)). Higher values of pH (≥9), temperature (≥32°C), DO (≥ 8 mg/L) and chlorophyll-a (≥ 1000 µg/L) were observed at the surface of BP, whereas lower values were shown at the bottom. Sedimentation combined with the synergetic effects of the physicochemical parameters and environmental factors would be responsible for the inactivation of E. coli in BP. It was concluded that the AR-BP could be applied as an alternative low-cost wastewater treatment technology for developing countries and recommended for reuse of their effluent for restricted peri-urban irrigation. PMID:26496019

  17. Microfluidic characteristics of a multi-holed baffle plate micro-reactor

    International Nuclear Information System (INIS)

    As part of a larger project aiming at development of a miniaturized hydrogen generator for small mobile/onboard fuel cell applications, a series of experiments was conducted on a novel micro-reactor to examine the effectiveness of its design in promoting the mixing of reactant agents. The reactor is essentially a tubular vessel fitted with a multi-holed baffle plate mounted on a central tube. The mixing phenomenon within the micro-reactor was studied using the micro-PIV (micro-particle image velocimetry) flow visualization technique. Experiments were conducted on a 1:1 scale replica of the reactor. Results indicate that the application of the multi-holed baffle plate considerably improves the mixing performance of the reactor when compared with a simpler co-axial jet tubular reactor. However, the geometrical characteristics of the baffle plate and central tube are found to have dramatic impacts upon the flow structure and mixing patterns within the reactor. Hence, the optimization of the reactor geometry is required to achieve the desirable mixing performance. For the range of Reynolds numbers studied here, the optimum reactor geometry is achieved when the central tube and baffle holes are of similar diameters and baffle holes are located half way between the stream-wise axis and the reactor wall

  18. Desempenho de processo anaeróbio em dois estágios (reator compartimentado seguido de reator UASB para tratamento de águas residuárias de suinocultura Performance of two-stage anaerobic process (baffled reactor (ABR followed by an upflow sludge blanket reactor (UASB treating swine wastewater

    Directory of Open Access Journals (Sweden)

    Gracie F. R. Fernandes

    2006-04-01

    Full Text Available Avaliou-se o efeito das águas residuárias de suinocultura com concentrações de sólidos suspensos totais em torno de 6.000 mg L-1 (DQOtotal variando de 7.557 a 11.640 mg L-1 no desempenho de processo anaeróbio em dois estágios compostos por reator compartimentado (ABR e reator de fluxo ascendente com manta de lodo (UASB, instalados em série, em escala-piloto (volumes de 530 e 120 L, respectivamente, submetidos a tempos de detenção hidráulica (TDH de 56 a 18 h no primeiro reator e de 13 a 4 h no segundo reator. As eficiências médias de remoção de DQOtotal variaram de 71,1 a 87,5% no reator ABR e de 41,5 a 50,1% no reator UASB, resultando em valores médios de 86,8 a 94,9% para o sistema de tratamento anaeróbio em dois estágios com carga orgânica volumétrica (COV, na faixa de 5,05 a 10,12 kg DQOtotal (m³ d-1, no reator ABR, e de 2,83 a 9,63 kg DQOtotal (m³ d-1, no reator UASB. As eficiências de remoção de SST e SSV foram da ordem de 95,6%. O teor de metano no biogás manteve-se acima de 70% para os dois reatores. A produção volumétrica de metano máxima de 0,755 m³ CH4 (m³ d-1 ocorreu no reator 1, com COV de 10,12 kg DQOtotal (m³ d-1 e TDH de 18 h. Os valores médios de pH variaram na faixa de 7,2 a 8,0 para os efluentes dos reatores 1 e 2. Os ácidos voláteis totais mantiveram-se estáveis com concentrações abaixo de 200 mg L-1. Com variações abruptas e acentuadas de concentrações de SST e DQOtotal do afluente, os reatores mantiveram as eficiências de remoção de DQO e sólidos suspensos, em torno de 70%, e a qualidade do biogás, com 80% de CH4.In this work it was evaluated the effect of swine wastewater with total suspended solid (TSS concentration around 6000 mg L-1 (CODtotal from 7557 to 11640 mg L-1 on the performance of two stage anaerobic process constituted of anaerobic baffled reactors (ABR and an upflow sludge blanket reactor (UASB installed in series, in pilot scale testing (volumes of 530 L and

  19. 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

    Full Text Available Neste trabalho, avaliou-se o efeito das águas residuárias de suinocultura, com concentrações médias de sólidos suspensos totais variando de 4.591 a 13.001 mg L-1, no desempenho de processo anaeróbio, em dois estágios, compostos por reator compartimentado (ABR e reator de fluxo ascendente com manta de lodo (UASB, instalados em série, em escala- -piloto (volumes de 530 e 120 L, respectivamente, submetidos a tempos de detenção hidráulica (TDH de 60; 36 e 24 h no primeiro reator, e de 13,6; 8,2 e 5,4 h no segundo reator. As eficiências médias de remoção de DQOtotal variaram de 69 a 84% no reator ABR e de 39 a 58% no reator UASB, resultando em valores médios de 87 a 94% para o sistema de tratamento anaeróbio em dois estágios, com carga orgânica volumétrica (COV na faixa de 11,5 a 18,0 g DQOtotal (L d-1 no reator ABR, e de 4,2 a 13,4 g DQOtotal (L d-1 no reator UASB. A produção volumétrica máxima de metano de 0,227 m³ CH4 (m³ reator d-1 ocorreu no reator UASB, com COV de 10,6 g DQOtotal (L d-1 e TDH de 5,4 h. As maiores eficiências de remoção de coliformes totais e termotolerantes (99,7%, DQOdiss (94%, SST (96%, NTK (71%, P-total (61% e outros nutrientes, no sistema de tratamento anaeróbio em dois estágios, foram obtidas com o TDH de 73,6 h e temperatura climatológica média de 24,6 °C, aplicando-se a menor COV (de 11,5 g DQOtotal (L d-1 no reator ABR, e de 4,2 g DQOtotal (L d-1 no reator UASB com a maior concentração de SST do afluente (13.001 mg L-1.In this work it was evaluated the effect of swine wastewater with mean total suspended solid (TSS concentration ranging from 4.591 to 13.001 mg L-1 on the performance of the anaerobic process in two stages composed of anaerobic baffled reactors (ABR and an upflow sludge blanket reactor (UASB, installed in series, in pilot scale testing (volumes of 530 and 120 L, respectively and with hydraulic detention times (HDT of 60; 36 and 24 h in the ABR reactor and 13.6; 8.2 and

  20. Membrane fouling behavior in anaerobic baffled membrane bioreactor under static operating condition.

    Science.gov (United States)

    Liu, Jiadong; Jia, Xiaolan; Gao, Bo; Bo, Longli; Wang, Lei

    2016-08-01

    A novel AnMBR combined with ABR as the anaerobic baffled membrane bioreactor (ABMBR) was developed for membrane fouling mitigation without any turbulence intensifying strategy to reduce the energy consumption further. The filtration time of this system lasted 14-25days under stable condition only with back-flushing every 48h. The polysaccharide accounted for 6.85±3.1% amount of total filter cake and the protein accounted for 4.12±2.1%, which took 79.12% and 11.12% of total area in laser scanning confocal microscope (CLSM) image. After filtration, 83.72±10.97% of turbidity, 59.28±16.46% of polysaccharide, 16.51% of tryptophan and 37.61% of humic-like substrates were rejected, respectively. The total membrane resistance at the end of each cycle was (4.47±0.99)×10(13)m(-1). And the resistance from filter cake was (4.15±1.00)×10(13)m(-1), which accounted for of 92.6±3.4% of total membrane resistance. PMID:27179954

  1. Irradiation-Induced Degradation Effects on Baffle-Former-Barrel Assembly of Reactor Vessel Internal

    International Nuclear Information System (INIS)

    Components of RVI are consisted of austenitic stainless steel materials which are known to have good strength, ductility, toughness and corrosion resistance. However, when placed in a PWR environment, these properties undergo changes due to long-term exposure to neutron irradiation, high temperature, reactor water, and loading. Especially irradiation aging in the reactor vessel internal components is characterized by a decrease in ductility and fracture toughness, increase in yield and ultimate tensile strength, and potential volume changes due to void formation. It is very important to determine when and where irradiation susceptibility may occur for the continued operation. This paper introduces the aging management strategy for the pressurized water reactor internal and investigates the effects of the irradiation-induced degradation of the baffle-former-barrel (BFB) assembly of the pressurized water reactor operating in Korea. This paper provides the methodologies and results for the functionality analysis on the baffle-former-barrel assembly. The highest temperatures are yielded from EOC of high leakage loading. The most highly irradiated areas are also closed to the core such as internal corners of the baffle plates. Coincidentally, the largest distortion occurs between these baffle plates. The distortion is carried by the bolts holding these plates. Characteristic to void swelling is the exponential growth with time. Void swelling predictions are therefore highly sensitive to the assumed fuel cycle management

  2. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter; Ahring, Birgitte Kiær; Raskin, L.

    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 for these ...... specific nucleic acid probes are discussed and exemplified by studies of anaerobic granular sludge, biofilm and digester systems...... malfunctions of anaerobic digesters occasionally experienced, leading to sub-optimal methane production and wastewater treatment. Using a variety of molecular techniques, we are able to determine which microorganisms are active, where they are active, and when they are active, but we still need to determine...... 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...

  3. Inspection and replacement of baffle assembly screws inside American reactor vessels

    International Nuclear Information System (INIS)

    The baffle assembly inside the vessel of a 900 MWe reactor designed by Framatome, is made up of 44 plates fixed on 8 horizontal supports by a system of about 1000 screws. These plates undergo high neutron flux and the problem of screw cracking appeared at the end of the eighties in the first-generation reactors. The first operation on a large scale concerning the screws of a Westinghouse type reactor, was performed on the Tihange-1 power plant where Framatome controlled 960 screws and replaced 91. In 1997 as a consequence of the Belgian and French feedback experience, American plant operators launched a vast program of preventive actions: material analysis, inspection of baffle plate screws and replacement of defective screws. This program was held in cooperation with EPRI (electric power research institute) and under the control of NRC (nuclear regulatory commission). Framatome Technologies Inc (FTI) was in charge of the in-situ inspection and replacement of the screws. FTI designed special tools and equipment adapted to the 2-loop American reactors but the basis ideas were those applied on the Tihange reactor. The successful experience of FTI has allowed the firm to be commissioned for 6 2-loops American reactors. (A.C.)

  4. 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...... and malfunctions of anaerobic digesters occasionally experienced, leading to sub-optimal methane production and wastewater treatment. Using a variety of molecular techniques, we are able to determine which microorganisms are active, where they are active, and when they are active, but we still need to determine...

  5. Physical-chemical and operational performance of an anaerobic baffled reactor (ABR treating swine wastewater = Desempenho físico-químico e operacional de um reator anaeróbio compartimentado (RAC como tratamento biológico preliminar de efluentes de suinocultura

    Directory of Open Access Journals (Sweden)

    Erlon Lopes Pereira

    2010-10-01

    Full Text Available Since hog raising concentrates a huge amount of swine manure in smallareas, 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 andhydraulic 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 performancein removing the organic matter from swine wastewater.A suinocultura por ser uma atividade pecuária concentradora de dejetos em pequenas áreas é considerada, pelos órgãos de gerência ambiental, como uma das atividades mais degradadoras do meio ambiente. Nesta pesquisa objetivou-se, por conseguinte, avaliar a utilização de um reator anaeróbio compartimentado (RAC, como unidade de prétratamento de um reator tipo UASB, em escala piloto, na adequação ambiental dos efluentes de suinocultura, avaliando critérios operacionais e a eficiência. As análises físico-químicasrealizadas foram: DQOtotal, DBO5, sólidos totais (ST, fixos (SF e voláteis (SV, temperatura, pH, nitrogênio total Kjeldahl, fósforo, acidez total e alcalinidade. A unidade RAC trabalhou com eficiência de 65,2 e 76,2% para a remoção de DQOtotal e DBO5

  6. Design of an Electrical Impedance Tomography Sensor for Flow Measurement in an Oscillatory Baffled Reactor

    Science.gov (United States)

    Vilar, G.; Williams, R. A.; Wang, M.

    2007-06-01

    In this paper, a new application of electrical impedance tomography (EIT) for an advanced on-line measurement is presented. This application involves the design, manufacture and adaptation of an EIT sensor for the measurement in an oscillatory baffled reactor (OBR). The main goal is to develop of a novel measurement and modeling method for control of the OBR. The reactor itself enables the production of water-in-oil/oil-in water emulsions along with the use of chemical reagents for a variety of manufacturing processes. Use of electrical tomography facilitates detailed measurement of the concentration and flow of components in the reactor. The paper reports on design philosophy of the EIT for this application that has not, to our knowledge, been reported previously.

  7. DECOLORIZATION AND BIOLOGICAL DEGRADATION OF AZO DYE REACTIVE RED2 BY ANAEROBIC/AEROBIC SEQUENTIAL PROCESS

    OpenAIRE

    A. Naimabadi ، H. Movahedian Attar ، A. Shahsavani

    2009-01-01

    This study investigates the anaerobic treatability of reactive Red2 in an anaerobic/aerobic sequential process. Laboratory scale anaerobic baffled reactor and fixed activated sludge reactor were operated at different organic loadings and hydraulic retention times. The effects of shock dye concentration on the chemical oxygen demand and color removal efficiencies were investigated in the anaerobic baffled reactor. The effect of hydraulic retention time on the color and chemical oxygen demand r...

  8. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

    The long retention time of the active biomass in the high-rate anaerobic digesters is the key factor for the successful application of the high rate anaerobic wastewater treatment. The long solids retention time is achieved due to the specific reactor configuration and it is enhanced...... 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...... of the role of the anaerobic digestion in the wastewater treatment plants from a pre-treatment method to the main biological treatment method. The application of staged high-rate anaerobic digesters has shown the larger potential among the recent developments in this direction. The most common high...

  9. Experimental study on the disinfection efficiencies of a continuous-flow ultrasound/ultraviolet baffled reactor.

    Science.gov (United States)

    Zhou, Xiaoqin; Guo, Hao; Li, Zifu; Zhao, Junyuan; Yun, Yupan

    2015-11-01

    A self-designed continuous-flow ultrasound/ultraviolet (US/UV) baffled reactor was tested in this work, and the disinfection efficiency of secondary effluent from a wastewater treatment plant (WWTP) was investigated in terms of the different locations of ultrasonic transducers inside the reactor under similar input power densities and specific energy consumptions. Results demonstrated that the two-stage simultaneous US/UV irradiation in both chambers 2 and 3 at a flow rate of 1200 L/h performed excellent disinfection efficiency. It achieved an average feacal coliforms concentration of 201±78 colony forming unit (CFU)/L in the effluent and an average of (4.24±0.26) log10 reduction. Thereafter, 8 days of continuous operation was performed under such a condition. A total of 31 samples were taken, and all the samples were analyzed in triplicate for feacal coliforms analysis. Experimental results showed that feacal coliforms concentrations remained at about 347±174 CFU/L under the selected optimum disinfection condition, even if the influent concentrations fluctuated from 3.97×10(5) to 3.57×10(6) CFU/L. This finding implied that all effluents of continuous-flow-baffled-reactor with simultaneous US/UV disinfection could meet the requirements of the discharge standard of pollutants for municipal WWTP (GB 18918-2002) Class 1-A (1000 CFU/L) with a specific energy consumption of 0.219 kWh/m(3). Therefore, the US/UV disinfection process has great potential for practical applications. PMID:26186823

  10. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær; Stamatelatou, K.; Lyberatos, G.

    2003-01-01

    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...... 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....

  11. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær; Stamatelatou, K.; Lyberatos, G.

    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...... 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....

  12. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... 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...

  13. Prediction of void swelling in the baffle ring of WWER-1000 reactors for service life of 30-60 years

    Science.gov (United States)

    Kalchenko, A. S.; Bryk, V. V.; Lazarev, N. P.; Voyevodin, V. N.; Garner, F. A.

    2013-06-01

    Major internal components of WWER-type nuclear reactors are made from annealed 18Cr10NiTi steel, a close analog to AISI 321. Void swelling of the baffle ring in particular could be a major factor limiting operation of the reactor beyond the current 30 years license. A predictive swelling equation is needed to forecast the spatial variation of swelling so as to identify those areas requiring additional attention. Available data on the swelling of this steel arising from irradiation in the BOR-60 fast reactor was combined with data from a heavy ion accelerator at higher displacement rates to formulate a predictive equation of swelling for the WWER-relevant range of temperature, irradiation dose and dose rates. This equation was used to estimate the swelling distribution over a cross-section of the baffle ring of a WWER reactor during a service life up to 60 years, reaching a local maximum of ˜30% swelling. It was shown that void swelling extends over a larger portion of the baffle ring than previously expected and exhibits a very complex and irregular distribution in response to complex distributions of temperature and dpa rate. Most importantly, as operation is extended beyond 30 years several areas of the ring may experience swelling in excess of 10% where void-induced embrittlement begins and one area may exceed 20% after 45 years, a swelling level where a complete loss of ductility is known to occur.

  14. DECOLORIZATION AND BIOLOGICAL DEGRADATION OF AZO DYE REACTIVE RED2 BY ANAEROBIC/AEROBIC SEQUENTIAL PROCESS

    Directory of Open Access Journals (Sweden)

    A. Naimabadi ، H. Movahedian Attar ، A. Shahsavani

    2009-04-01

    Full Text Available This study investigates the anaerobic treatability of reactive Red2 in an anaerobic/aerobic sequential process. Laboratory scale anaerobic baffled reactor and fixed activated sludge reactor were operated at different organic loadings and hydraulic retention times. The effects of shock dye concentration on the chemical oxygen demand and color removal efficiencies were investigated in the anaerobic baffled reactor. The effect of hydraulic retention time on the color and chemical oxygen demand removal efficiencies were also investigated in the aerobic reactor. The studies were carried out in continuous mode and the effluent of the anaerobic baffled reactor was used as feed for the fixed activated sludge reactor. Chemical oxygen demand removal efficiency of 54.5% was obtained at HRT =1 day in the anaerobic reactor. The average color removal was 89.5%. Chemical oxygen demand removal efficiency of 69% was obtained at HRT =7 h in the aerobic fixed activated sludge reactor. A slight decrease of the color was also observed in the aerobic reactor. This investigation has shown that successful treatment of a highly colored wastewater is possible in the anaerobic baffled reactor. Also the results showed that, anaerobic biological system has higher efficiency in dye removal than fixed activated sludge system, while aerobic system has higher efficiency in chemical oxygen demand removal comparing with the anaerobic baffled reactor.

  15. 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...... for electricity production from existing anaerobic reactors or other anaerobic environments such as sediments. The advantage of the SMFC is that no special anaerobic chamber (anode chamber) is needed, as existing anaerobic reactors can be used, where the cathode chamber and anode electrode are immersed....

  16. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... 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...... 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....

  17. Coliform and helminth eggs removal in a combined UASB reactor-baffled pond system in Brazil: performance evaluation and mathematical modelling.

    Science.gov (United States)

    von Sperling, M; Chernicharo, C A L; Soares, A M E; Zerbini, A M

    2002-01-01

    The paper presents the monitoring results of a pilot UASB reactor followed by a baffled polishing pond treating domestic sewage in Brazil. Longitudinal profiles of E coli and helminth eggs along the baffled pond have been undertaken. The experimental results have been compared with von Sperling's model for coliform removal and Ayres' model for helminth eggs removal, and the fitting was considered satisfactory in both cases. The distribution of the helminth species along the system is also presented. PMID:12188551

  18. Evaluation of neutron fluence in nuclear reactor internal structures due to IASCC (Focused on the baffle structure for Kori Unit 2 reactor)

    International Nuclear Information System (INIS)

    Neutron fluence evaluation has been currently performed on the reactor vessel itself in an operating nuclear power plant in order to evaluate the radiation embrittlement which is directly related to plant safety as well as plant operating licence and has never been done on reactor internal structures such as baffle former bolt based on the operating history, However, as the operating year increases, damages may occur in the internal structures and resulting in the shutdown of the plant and the replacement of the structure causing economic disadvantage as well as severe effect in the integrity of the plant. Neutron flux and fluences on the baffle area for thr Kori unit 2 has been performed from the start of the reactor until 21st fuel cycle using real plant operating conditions such as operating temperature, pressure and fuel loading pattern and the maximum fluence in the baffle area was evaluated as about 4.3 x 1022 [n/cm2] at the 21st cycle and about 6.8 x 1022 [n/cm2] at the end of life (32EFPY) when assuming the average plant performance to be 80%

  19. 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.

  20. Control of calcium carbonate precipitation in anaerobic reactors.

    OpenAIRE

    Langerak, van, B.

    1998-01-01

    Anaerobic treatment of waste waters with a high calcium content may lead to excessive precipitation of calcium carbonate. So far, no proper methods were available to predict or reduce the extent of precipitation in an anaerobic treatment system. Moreover, it also was not clear to what extent precipitation in an anaerobic reactor can be tolerated because adequate knowledge on the structure and quality of methanogenic sludges with high calcium carbonate content was lacking. In this thesis, the ...

  1. Solids removal in upflow anaerobic reactors, a review

    NARCIS (Netherlands)

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

    2003-01-01

    This desk study deals with the mechanisms and parameters affecting particles separation from wastewater in mainly upflow anaerobic reactors. Despite the fact that the functioning of upflow anaerobic sludge blanket (UASB) systems depends on both physical parameters and biological processes, the physi

  2. Methanol conversion in high-rate anaerobic reactors

    NARCIS (Netherlands)

    Weijma, J.; Stams, A.J.M.

    2001-01-01

    An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens inter

  3. 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.

  4. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

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

    2003-01-01

    role of the anaerobic digestion in the wastewater treatment plants from a pre-treatment method to the main biological treatment method. The application of staged high-rate anaerobic digesters has shown the larger potential among the recent developments in this direction. The most common high...

  5. 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. PMID:26167485

  6. Treatment of domestic sewage in a two-step system anaerobic filter/anaerobic hybrid reactor at low temperature

    NARCIS (Netherlands)

    Elmitwalli, T.A.; Zeeman, G.; Oahn, K.L.T.; Lettinga, G.

    2002-01-01

    The treatment of domestic sewage at low temperature of 13 degrees Celsius was investigated in a two-step system consisting of an anaerobic filter (AF) + an anaerobic hybrid (AH) reactor operated at different hydraulic retention times (HRTs)

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

    OpenAIRE

    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 ...

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

    DEFF Research Database (Denmark)

    2014-01-01

    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......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...

  9. Evaluation Of Communal Wastewater Treatment Plant Operating Anaerobic Baffled Reactor And Biofilter

    OpenAIRE

    Evy Hendriarianti; Nieke Karnaningroem

    2016-01-01

    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 wastewat...

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

    OpenAIRE

    Trilita Minarni Nur; Hendrasarie Novirina; Wahjudijanto Iwan

    2016-01-01

    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 was...

  11. 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.

  12. 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.......(max), and the half saturation constant, K-m, were initially estimated by applying the integrated Michaelis-Menten equation. A(max) was in the range from 22.8 to 29.1 mu mol gVS(-1) h(-1) while K-m, was in the range from 0.46-0.95 mM. In general, A(max) gave a good reflection of the reactor performances. Secondly...

  13. 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...

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

    International Nuclear Information System (INIS)

    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/m3 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

  15. 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

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

    Directory of Open Access Journals (Sweden)

    Jin Wang

    2015-01-01

    Full Text Available 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.

  17. Anaerobic treatment of natural tannin extracts in UASB reactors.

    Science.gov (United States)

    López-Fluza, J; Omil, F; Méndez, R

    2003-01-01

    Tannin extracts are substances commonly used in leather production processes. Since most of the steps of tannery manufacturing processes are carried out in aqueous environments, the presence of these compounds in the wastewaters is important. The aim of this work is to study the feasibility of the anaerobic degradation of three natural tannin extracts in three Upflow Anaerobic Sludge Blanket (UASB) reactors, which were fed with increasing concentrations of two condensed (quebracho and wattle) and one hydrolysable tannin extract (chestnut). Concentrations of applied extracts were 100, 200, 400, 800 and 1,000 mg/l, and 5 g/l of glucose was used as cosubstrate. Reactors were operated during 210 days and their performance was evaluated from the values of total and soluble COD, total and intermediate alkalinity, volatile fatty acids, pH and UV absorption at 280 nm. COD removal efficiencies higher than 85% were achieved in all cases. However, tannin extract removal efficiencies (based on UV-280 nm absorption measurements) were significantly lower, around 20% for condensed extracts and 60% for the hydrolysable one, when the reactors operated with the highest tannin extract concentration. The operation of the reactors was stable, commonly with alkalinity ratios below 0.30. Mass balances carried out indicate that most of the COD removal efficiencies are due to the removal of the readily biodegradable organic matter (glucose), whereas the tannin extracts are hardly anaerobically biodegradable, especially condensed extracts (wattle and quebracho). PMID:14640213

  18. 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.

  19. PCB dechlorination in anaerobic soil slurry reactors

    International Nuclear Information System (INIS)

    Many industrial locations, including the US Department of Energy's, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges, including mixed wastes; however, a practical remediation technology has not yet been demonstrated. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River have been used to obtain anaerobic dechlorination of PCBS. The onset of dechlorination activity can be accelerated by addition of nutritional amendments and inducers. After 15 weeks of incubation with PCB-contaminated soil and nutrient solution, dechlorination has been observed under several working conditions. The best results show that the average chlorine content steadily dropped from 4.3 to 3.5 chlorines per biphenyl over a 15-week period

  20. Device to measure underwater the hardness of a vertical wall of the core baffle assembly of a pressurized water nuclear reactor

    International Nuclear Information System (INIS)

    The device comprises a hollow vertical rod handled from the edge of the pool. A body integral with the rod at its lower end, has a mobile piston, housed in a first chamber, provided with bearing means to fit against two perpendicular walls; a second piston housed in the second chamber carries a hardness measuring head to make a mark on the wall opposite to one of the two perpendicular walls. A source of hydraulic fluid communicates with the chambers through the rod. The invention applies, more particularly, to the determination of influence of irradiation on the walls of the core baffle assembly of a nuclear reactor, after a certain operating period

  1. TREATMENT OF POME BY PILOT PLANT ANAEROBIC FLUIDISED BED REACTOR

    OpenAIRE

    Abdullah Al-Mamun; Azni Idris

    2010-01-01

    A pilot scale anaerobic fluidised bed reactor (AnFBR) of 2000 L capacity was studied to determine its performance to treat palm oil mill effluent (POME). The pilot plant was operated at ambient temperature with diluted POME as substrate. It took 17 days for the start-up of the reactor with pre-seeded sand media. The AnFBR was capable to remove a large portion of organics at relatively shorter retention time. Maximum and minimum COD removal efficiency of 85% and 65% were attained at a ...

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

    OpenAIRE

    Erlon Lopes Pereira; Claudio Milton Montenegro Campos; Cristine Serafine Neves; Regina Batista Vilas Boas

    2014-01-01

    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. T...

  3. 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

    with diluted SSL and pretreated SSL indicated a potential of 12–22 l methane per litre SSL, which corresponds to 0.13–0.22 l methane ðg VSÞ1 and COD removal of up to 37%. COD removal in a mesophilic upflow anaerobic sludge blanket, UASB, reactor ranged from10% to 31% at an organic loading rate, OLR, of 10–51 g...... ðl dÞ1 and hydraulic retention time from 3.7 to 1.5 days. The biogas productivity was 3 l ðlreactor dÞ1, with a yield of 0.05 l gas ðg VSÞ1. These results suggest that anaerobic digestion in UASB reactors may provide a new alternative for the treatment of SSL to other treatment strategies......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...

  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

    A key parameter for understanding and controling the anaerobic biogas process is the concentration of volatile fatty acids (VFA). However, this information has so far been limited to off-line measurements using labor-intensive methods. We have developed a new technique that has made it possible...... 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...... 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...

  5. Cosmetic wastewater treatment by upflow anaerobic sludge blanket reactor

    International Nuclear Information System (INIS)

    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-1 day-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.

  6. Anaerobic biogranulation in a hybrid reactor treating phenolic waste

    International Nuclear Information System (INIS)

    Granulation was examined in four similar anaerobic hybrid reactors 15.5 L volume (with an effective volume of 13.5 L) during the treatment of synthetic coal wastewater at the mesophilic temperature of 27 ± 5 deg. C. The hybrid reactors are a combination of UASB unit at the lower part and an anaerobic filter at the upper end. Synthetic wastewater with an average chemical oxygen demand (COD) of 2240 mg/L, phenolics concentration of 752 mg/L and a mixture of volatile fatty acids was fed to three hybrid reactors. The fourth reactor, control system, was fed with a wastewater containing sodium acetate and mineral nutrients. Coal waste water contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3 mg/L) as major phenolic compounds. A mixture of anaerobic digester sludge and partially granulated sludge (3:1) were used as seed materials for the start up of the reactors. Granules were observed after 45 days of operation of the systems. The granules ranged from 0.4 to 1.2 mm in diameter with good settling characteristics with an SVI of 12 mL/g SS. After granulation, the hybrid reactor performed steadily with phenolics and COD removal efficiencies of 93% and 88%, respectively at volumetric loading rate of 2.24 g COD/L d and hydraulic retention time of 24 h. The removal efficiencies for phenol and m/p-cresols reached 92% and 93% (corresponding to 450.8 and 153 mg/L), while o-cresol was degraded to 88% (corresponding to 51.04 mg/L). Dimethyl phenols could be removed completely at all the organic loadings and did not contribute much to the residual organics. Biodegradation of o-cresol was obtained in the hybrid-UASB reactors

  7. TREATMENT OF POME BY PILOT PLANT ANAEROBIC FLUIDISED BED REACTOR

    Directory of Open Access Journals (Sweden)

    Abdullah Al-Mamun

    2010-09-01

    Full Text Available A pilot scale anaerobic fluidised bed reactor (AnFBR of 2000 L capacity was studied to determine its performance to treat palm oil mill effluent (POME. The pilot plant was operated at ambient temperature with diluted POME as substrate. It took 17 days for the start-up of the reactor with pre-seeded sand media. The AnFBR was capable to remove a large portion of organics at relatively shorter retention time. Maximum and minimum COD removal efficiency of 85% and 65% were attained at a loading rate of 4.0 and 13.8 kgCOD/m3.d. BOD and TSS removal rates varied within the range of 64% - 91% and 68% - 89%, respectively. The AnFBR exhibited low sludge production with lower sludge volume indices (SVI. Maximum and minimum effluent indices for the effluent were 35 mL/g and 11 mL/g, respectively. Low SVI values indicated that, anaerobic fluidised bed reactors generate less sludge with fast settling properties. Promising performance at ambient temperature and for detention time shorter than the present practices supported the possibility of AnFBR to treat POME to meet the new requirement set by the DOE Malaysia.

  8. Effect of increasing nitrobenzene loading rates on the performance of anaerobic migrating blanket reactor and sequential anaerobic migrating blanket reactor/completely stirred tank reactor system

    International Nuclear Information System (INIS)

    A laboratory scale anaerobic migrating blanket reactor (AMBR) reactor was operated at nitrobenzene (NB) loading rates increasing from 3.33 to 66.67 g NB/m3 day and at a constant hydraulic retention time (HRT) of 6 days to observe the effects of increasing NB concentrations on chemical oxygen demand (COD), NB removal efficiencies, bicarbonate alkalinity, volatile fatty acid (VFA) accumulation and methane gas percentage. Moreover, the effect of an aerobic completely stirred tank reactor (CSTR) reactor, following the anaerobic reactor, on treatment efficiencies was also investigated. Approximately 91-94% COD removal efficiencies were observed up to a NB loading rate of 30.00 g/m3 day in the AMBR reactor. The COD removal efficiencies decreased from 91% to 85% at a NB loading rate of 66.67 g/m3 day. NB removal efficiencies were approximately 100% at all NB loading rates. The maximum total gas, methane gas productions and methane percentage were found to be 4.1, 2.6 l/day and 59%, respectively, at a NB loading rate of 30.00 g/m3 day. The optimum pH values were found to be between 7.2 and 8.4 for maximum methanogenesis. The total volatile fatty acid (TVFA) concentrations in the effluent were 110 and 70 mg/l in the first and second compartments at NB loading rates as high as 66.67 and 6.67 g/m3 day, respectively, while they were measured as zero in the effluent of the AMBR reactor. In this study, from 180 mg/l NB 66 mg/l aniline was produced in the anaerobic reactor while aniline was completely removed and transformed to 2 mg/l of cathechol in the aerobic CSTR reactor. Overall COD removal efficiencies were found to be 95% and 99% for NB loading rates of 3.33 and 66.67 g/m3 day in the sequential anaerobic AMBR/aerobic CSTR reactor system, respectively. The toxicity tests performed with Photobacterium phosphoreum (LCK 480, LUMIStox) and Daphnia magna showed that the toxicity decreased with anaerobic/aerobic sequential reactor system from the influent, anaerobic and to

  9. 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.

  10. TREATMENT OF METHANOLIC WASTEWATER BY ANAEROBIC DOWN-FLOW HANGING SPONGE (ANDHS) REACTOR AND UASB REACTOR

    Science.gov (United States)

    Sumino, Haruhiko; Wada, Keiji; Syutsubo, Kazuaki; Yamaguchi, Takashi; Harada, Hideki; Ohashi, Akiyoshi

    Anaerobic down-flow hanging sponge (AnDHS) reactor and UASB reactor were operated at 30℃ for over 400 days in order to investigate the process performance and the sludge characteristics of treating methanolic wastewater (2 gCOD/L). The settings OLR of AnDHS reactor and of UASB reactor were 5.0 -10.0 kgCOD/m3/d and 5.0 kgCOD/m3/d. The average of the COD removal demonstrated by both reactors were over 90% throughout the experiment. From the results of methane producing activities and the PCR-DGGE method, most methanol was directly converted to methane in both reactors. The conversion was carried out by different methanogens: one closely related to Methanomethylovorans hollandica in the AnDHS retainted sludge and the other closely related to Methanosarcinaceae and Metanosarciales in the UASB retainted sludge.

  11. Extracellular Polymeric Substances (EPS) in Upflow Anaerobic Sludge Blanket (UASB) Reactors Operated under High Salinity Conditions

    NARCIS (Netherlands)

    Ismail, S.; Parra, de la C.J.; Temmink, B.G.; Lier, van J.B.

    2010-01-01

    Considering the importance of stable and well–functioning granular sludge in anaerobic high rate reactors, a series of experiments were conducted to determine the production and composition of EPS in high sodium concentrations wastewaters pertaining to anaerobic granule properties. The UASB reactors

  12. Experimental and theoretical investigation of anaerobic fluidized bed biofilm reactors

    Directory of Open Access Journals (Sweden)

    M. Fuentes

    2009-09-01

    Full Text Available This work presents an experimental and theoretical investigation of anaerobic fluidized bed reactors (AFBRs. The bioreactors are modeled as dynamic three-phase systems. Biochemical transformations are assumed to occur only in the fluidized bed zone. The biofilm process model is coupled to the system hydrodynamic model through the biofilm detachment rate; which is assumed to be a first-order function of the energy dissipation parameter and a second order function of biofilm thickness. Non-active biomass is considered to be particulate material subject to hydrolysis. The model includes the anaerobic conversion for complex substrate degradation and kinetic parameters selected from the literature. The experimental set-up consisted of two mesophilic (36±1ºC lab-scale AFBRs (R1 and R2 loaded with sand as inert support for biofilm development. The reactor start-up policy was based on gradual increments in the organic loading rate (OLR, over a four month period. Step-type disturbances were applied on the inlet (glucose and acetic acid substrate concentration (chemical oxygen demand (COD from 0.85 to 2.66 g L-1 and on the feed flow rate (from 3.2 up to 6.0 L d-1 considering the maximum efficiency as the reactor loading rate switching. The predicted and measured responses of the total and soluble COD, volatile fatty acid (VFA concentrations, biogas production rate and pH were investigated. Regarding hydrodynamic and fluidization aspects, variations of the bed expansion due to disturbances in the inlet flow rate and the biofilm growth were measured. As rate coefficients for the biofilm detachment model, empirical values of 3.73⋅10(4 and 0.75⋅10(4 s² kg-1 m-1 for R1 and R2, respectively, were estimated.

  13. 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.

  14. Metal supplementation to anaerobic granular sludge bed reactors: an environmental engineering approach

    OpenAIRE

    Gonzalez Fermoso, F.

    2008-01-01

    The objective of this research is the optimization of essential metal dosing in upflow anaerobic sludge bed (UASB) reactors used for methanogenic wastewater treatment. Optimization of essential metal dosing in UASB reactors is a compromise between achieving the maximal biological activity of the biomass present in the reactor, while minimizing the costs of the supplied metal and the metal losses into the environment. The fate of metals in the anaerobic granular sludge is studied. The boundary...

  15. Structure and Dynamics of Anaerobic Bacterial Aggregates in a Gas-Lift Reactor

    OpenAIRE

    Beeftink, H.H.; Staugaard, P

    1986-01-01

    Anaerobic mixed-culture aggregates, which converted glucose to acetic, propionic, butyric, and valeric acids, were formed under controlled conditions of substrate feed (carbon limitation) and hydraulic regimen. The continuous-flow system used (anaerobic gas-lift reactor) was designed to retain bacterial aggregates in a well-mixed reactor. Carrier availability (i.e., liquid-suspended sand grains) proved necessary for bacterial aggregate formation from individual cells during reactor start-up. ...

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

    OpenAIRE

    ZAIAT M.; L.G.T. Vieira; A.K.A. Cabral; I.R. de Nardi; F.J. Vela; E. Foresti

    1997-01-01

    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 w...

  17. Energy recovery from municipal solid waste in an anaerobic reactor.

    Science.gov (United States)

    Jeyapriya, S P; Saseetharan, M K

    2008-07-01

    Anaerobic digestion of municipal solid waste was carried out in the laboratory at room temperature to assess the bio-energy production from municipal solid waste (MSW) with high total solids content. The total biogas production from the municipal garbage was found to be 3.2 L in 120 days. The results from the biomethanation process showed that an increase in gas production was observed with increase in digestion period when the bioconversion parameters were found to be favorable for the production of gas. Changes in the parameters, such as pH, affected the production of gas significantly. Samples taken from the reactor at definite interval of time during the degradation process showed considerable reduction in total volatile solids, total carbon, total nitrogen and COD, etc. indicating the waste stabilization. PMID:19552079

  18. 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. PMID:25746594

  19. Hydraulic optimization of membrane bioreactor via baffle modification using computational fluid dynamics.

    Science.gov (United States)

    Yan, Xiaoxu; Xiao, Kang; Liang, Shuai; Lei, Ting; Liang, Peng; Xue, Tao; Yu, Kaichang; Guan, Jing; Huang, Xia

    2014-11-01

    Baffles are a key component of an airlift membrane bioreactor (MBR), which could enhance membrane surface shear for fouling control. In order to obtain an optimal hydraulic condition of the reactor, the effects of baffle location and size were systematically explored in this study. Computational fluid dynamics (CFD) was used to investigate the hydrodynamics in a bench-scale airlift flat sheet MBR with various baffle locations and sizes. Validated simulation results showed that side baffles were more effective in elevating membrane surface shear than front baffles. The maximum average shear stress was achieved by adjusting baffle size when both front and side baffles were installed. With the optimized baffle configuration, the shear stress was 10-30% higher than that without baffles at a same aeration intensity (specific air demand per membrane area in the range of 0-0.45m(3)m(-2)h(-1)). The effectiveness of baffles was particularly prominent at lower aeration intensities. PMID:25465790

  20. Study of vibration analysis method for fluid-structure interaction of a top-entry loop type FBR; experiment and analysis of the thermal baffle in the reactor vessel

    International Nuclear Information System (INIS)

    This paper presents the results of vibration experiments and analyses using a finite element method (FEM) performed on a thermal baffle of the reactor vessel wall in a top-entry loop type fast breeder reactor (FBR). Two types of tests and analyses were carried out. The first 'Multiple Cylinder Test' was to understand the fluid-structure interacting vibration of thin multiple cylinders (flexible thermal baffle), using a 1/5-scale model of the reactor vessel and the thermal baffle of the top-entry loop type FBR reactor structure. The second 'Non-linear Effect Test' was to understand the basic phenomena of fluid-structure interacting vibration under non-linear fluid pressure conditions, using a rigid double cylindrical basic model. The results of the multiple cylinder test showed that in the beam vibration including oval mode, the natural frequency can be well estimated by FEM analysis code FINAS. The results of the non-linear effect tests showed that virtual mass is constant even under non- linear pressure conditions, and virtual mass can be well estimated by a formulation based on potential flow theory. (author)

  1. Employment of anaerobic reactors in real scale and polishing ponds for removal of eggs Ascaris suum of swine effluent

    Directory of Open Access Journals (Sweden)

    Ana Cristina Araujo Pinto

    2014-02-01

    Full Text Available The swine confinement farms and the improper disposal of their wastes carry result in contamination of water and soil. On many farms is common slurry application to soil as a means of fertilization, but without any control over the quality of the effluent being released. What is a parasite Ascaris suum from pigs can infect humans, but is not given due importance to the presence of this contaminant as soil and water. In this work the effluent of a pig was treated in a system composed of anaerobic baffled reactor (ABR and a UASB followed by polishing ponds for removal of helminthes eggs. The experiment was conducted at the Hélio Barbosa Experimental Farm pig in the city of Igarapé / MG. Values found in the influent of helminthes eggs in the range from 2891 to 88,848 eggs L-1, while the effluent showed absence of eggs, showing the high efficiency of the treatment system. While the sludge ponds, it showed high concentration of viable eggs ranged from 10.1% to 59.8%, not being in conformity with the requirements for reuse in agriculture.

  2. Stability of anaerobic reactors under micro-aeration conditions

    International Nuclear Information System (INIS)

    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)

  3. Baffle construction notes

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1998-01-01

    The design process for multi-stage high performance straylight suppression baffles for star trackers are described. Furthermore details for manufacturing are given......The design process for multi-stage high performance straylight suppression baffles for star trackers are described. Furthermore details for manufacturing are given...

  4. REMOVAL EFFICIENCY OF NITROGEN AND PHOSPHORUS FROM DAIRY WASTEWATER ANAEROBIC REACTOR WITH CAGE MIXING SYSTEM

    OpenAIRE

    Anna Hajduk; Marcin Dębowski; Marcin Zieliński; Agnieszka Ligus

    2016-01-01

    An alternative to aerobic wastewater treatment systems are anaerobic reactors. When designing anaerobic reactors attention is paid to the appropriate filling, pumping systems, or mixing systems, enabling the re-duction of technological limitations, which contribute to the improvement of end effects such as, quantity and quality of the resulting biogas and the quality of treated wastewater. Described experiment related to researches on the evaluation of the efficiency of removing contamina-tio...

  5. 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.

  6. ANAEROBIC/AEROBIC BIODEGRADATION OF PENTACHLOROPHENOL USING GAC FLUIDIXED BED REACTORS: OPTIMIZATION OF THE EMPTY BED CONTACT TIME

    Science.gov (United States)

    An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to approximately equimolar concentrations (>99%) of chlorophenol (CP) in a granular activa...

  7. 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

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

    International Nuclear Information System (INIS)

    This study evaluated the anaerobic degradation of landfill leachate and sulfate reduction as a function of COD/(SO42-) 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/(SO42-) 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/(SO42-) 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.

  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

    . Using upflow anaerobic sludge blanket (UASB) reactors, it was shown that codigestion of OME with swine manure (up to 50% OME) was successful with a COD reduction up to 75%. The process was adapted for degradation of OME with stepwise increase of the OME load to the UASB reactor. The results showed...... that the high content of ammonia in swine manure, together with content of other nutrients, make it possible to degrade OME without addition of external alkalinity and without addition of external nitrogen source. Anaerobic treatment of OME in UASB reactors resulted in reduction of simple phenolic compounds......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. Control of calcium carbonate precipitation in anaerobic reactors.

    NARCIS (Netherlands)

    Langerak, van E.P.A.

    1998-01-01

    Anaerobic treatment of waste waters with a high calcium content may lead to excessive precipitation of calcium carbonate. So far, no proper methods were available to predict or reduce the extent of precipitation in an anaerobic treatment system. Moreover, it also was not clear to what extent precipi

  11. Celebrating 40 years anaerobic sludge bed reactors for industrial wastewater treatment

    NARCIS (Netherlands)

    Van Lier, J.B.; Van der Zee, F.P.; Frijters, C.T.M.J.; Ersahin, M.E.

    2015-01-01

    In the last 40 years, anaerobic sludge bed reactor technology evolved from localized lab-scale trials to worldwide successful implementations at a variety of industries. High-rate sludge bed reactors are characterized by a very small foot print and high applicable volumetric loading rates. Best perf

  12. Metal supplementation to anaerobic granular sludge bed reactors: an environmental engineering approach

    NARCIS (Netherlands)

    Gonzalez Fermoso, F.

    2008-01-01

    The objective of this research is the optimization of essential metal dosing in upflow anaerobic sludge bed (UASB) reactors used for methanogenic wastewater treatment. Optimization of essential metal dosing in UASB reactors is a compromise between achieving the maximal biological activity of the bio

  13. 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.

  14. 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

  15. 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......The advantageous performance of the UASB reactors is due to the immobilisation of the active biomass, since bacteria coagulate forming aggregates usually called granules. Changes in organic loading rate, hydraulic loading rate or influent substrate composition usually result in changes in granule...... 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....

  16. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

    OpenAIRE

    Meiqing Lu; Xiaojun Niu; Wei Liu; Jun Zhang; Jie Wang; Jia Yang; Wenqi Wang; Zhiquan Yang

    2016-01-01

    The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment...

  17. 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.

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

    International Nuclear Information System (INIS)

    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

  19. 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.

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

    OpenAIRE

    Laura C. Zuluaga; Luz N. Naranjo; Jan Svojitka; Thomas Wintgens; Manuel Rodriguez; Nicolas Ratkovich

    2015-01-01

    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, wher...

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

    OpenAIRE

    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, providing optimal conditions for organic matter degradation. AnMBRs offer high quality effluents free of solids and complete retention of biomass, regardless its settling and/or granulation properties. Th...

  2. Monitoring Methanotrophic Bacteria in Hybrid Anaerobic-Aerobic Reactors with PCR and a Catabolic Gene Probe

    OpenAIRE

    Miguez, Carlos B; Shen, Chun F; Bourque, Denis; Guiot, Serge R; Groleau, Denis

    1999-01-01

    We attempted to mimic in small upflow anaerobic sludge bed (UASB) bioreactors the metabolic association found in nature between methanogens and methanotrophs. UASB bioreactors were inoculated with pure cultures of methanotrophs, and the bioreactors were operated by using continuous low-level oxygenation in order to favor growth and/or survival of methanotrophs. Unlike the reactors in other similar studies, the hybrid anaerobic-aerobic bioreactors which we used were operated synchronously, not...

  3. Performance of anaerobic sequencing batch reactors (pilot-scale in domestic sewage treatment

    Directory of Open Access Journals (Sweden)

    Eugenio Foresti

    2005-02-01

    Full Text Available This study shows the results obtained during 70 days using four pilot scale anaerobic sequencing batch reactors, for sewage system treatment of the campus of the University of São Paulo in São Carlos – SP. Each reactor system with 1.2 m³ of total volume, was designed for the treatment of 1.95 m³d³ of domestic sewage, with geometrical conceptions (ratio H-height/D-diameter, mechanical conceptions (mechanical mixing or liquid re-circulation and different biomass retention type. Three of them were ASBR (AnaerobicSequencing Batch Reactor with granular biomass and another one was an ASBBR (Anaerobic Sequencing Batch Biofilm Reactor with biomass consisting of cubic matrices of polyurethane foam. The reactors were inoculated and operated within an 8-hour batch cycle. The reactors monitoring included the oxygen chemical demand (OCD, pH, total suspended solids (TSS and volatile suspended solids, volatile fatty acids, alkalinity to bicarbonate and methane concentration. Both ASBR reactors with liquid re-circulation did not show a satisfactory performance. The average values of OCD and TSS removal were close to 40% and 60% respectively. In the ASBR reactors with mechanical mixing and ASBBR with immobilized biomass, showed better results. The ASBBR reactor reached average efficiency of 61% and 75% in OCD and TSS removal, while in the ASBR with mechanical mixing, it reached 60% and 79%, respectively.

  4. 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

  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. PMID:24520716

  6. 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...

  7. 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.

  8. 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...

  9. 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 was...

  10. 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...

  11. Anaerobic degradation of aircraft deicing fluid (ADF) in upflow anaerobic sludge blanket (UASB) reactors and the fate of ADF additives

    Science.gov (United States)

    Pham, Thi Tham

    2002-11-01

    A central composite design was employed to methodically investigate anaerobic treatment of aircraft deicing fluid (ADF) in bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactors. A total of 23 runs at 17 different operating conditions were conducted in continuous mode. The development of four empirical models describing process responses (i.e., chemical oxygen demand (COD) removal efficiency, biomass specific acetoclastic activity, methane production rate, and methane production potential) as functions of ADF concentration, hydraulic retention time (HRT), and biomass concentration is presented. Model verification indicated that predicted responses (COD removal efficiencies, biomass specific acetoclastic activity, and methane production rates and potential) were in good agreement with experimental results. Biomass specific acetoclastic activity was improved by almost two-fold during ADF treatment in UASB reactors. For the design window, COD removal efficiencies were higher than 90%. Predicted methane production potentials were close to theoretical values, and methane production rates increased as the organic loading rate (OLR) was increased. ADF toxicity effects were evident for 1.6% ADF at medium specific organic loadings (SOLR above 0.5 g COD/g VSS/d). In contrast, good reactor stability and excellent removal efficiencies were achieved at 1.2% ADF for reactor loadings approaching that of highly loaded systems (0.73 g COD/g VSS/d). Acclimation to ADF resulted in an initial reduction in the biomass settling velocity. The fate of ADF additives was also investigated. There was minimal sorption of benzotriazole (BT), 5-methyl-1 H-benzotriazole (MeBT), and 5,6-dimethyl-1 H-benzotriazole (DiMeBT) to anaerobic granules. A higher sorption capacity was measured for NP. Active transport may be one of the mechanisms for NP sorption. Ethylene glycol degradation experiments indicated that BT, MeBT, DiMeBT, and the nonionic surfactant Tergitol NP-4 had no significant

  12. 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...

  13. 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.

  14. A Downflow Hanging Sponge (DHS) reactor for faecal coliform removal from an Upflow Anaerobic Sludge Bed (UASB) effluent

    NARCIS (Netherlands)

    Yaya Beas, R.E.; Kujawa-Roeleveld, K.; Lier, van J.B.; Zeeman, G.

    2015-01-01

    This research was conducted to study the faecal coliforms removal capacity of Downflow Hanging Sponge (DHS) reactors as a post-treatment for an Upflow Anaerobic Sludge Blanket (UASB) reactor. Three long-term continuous lab-scale DHS reactors i.e. a reactor with cube type sponges without recirculatio

  15. Effect of internal recirculation velocity in an anaerobic sequencing batch reactor (ASBR)

    OpenAIRE

    G. Z. Maurina; L. M. Rosa; L. L. Beal; C. Baldasso; J. R. Gimenez; Torres, A.P. (Asvin Pérez); M.P. Sousa

    2014-01-01

    This paper discusses the effect of different internal recirculation velocities on the mixture and shear stress on the flocs in an anaerobic sequencing batch reactor (ASBR). Thus, simulations are performed using a computational fluid dynamics (CFD) tool to evaluate this dependency. The analysis of velocities and turbulent kinetic energy indicates that the highest flow evaluated (0.003 m³/s) results in better mixing within the reactor. However, care must be taken with the recycling pipe size, i...

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.; Ma, W.C.; Han, H.J.; Li, H.Q.; Yuan, M. [Harbin Institute of Technology, Harbin (China)

    2011-02-15

    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{sup o}C) reactor as a control, thermophilic anaerobic digestion (55 {+-} 2{sup o}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{sup 3} d) and HRT of 24h: 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 pre-treatment was done. The results suggested that thermophilic anaerobic digestion improved significantly both anaerobic and aerobic biodegradation of LCGW.

  17. 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. PMID:21112778

  18. 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.

  19. Improving the cyanide toxicity tolerance of anaerobic reactor: Microbial interactions and toxin reduction.

    Science.gov (United States)

    Gupta, Pragya; Ahammad, S Z; Sreekrishnan, T R

    2016-09-01

    Anaerobic biological treatment of high organics containing wastewater is amongst the preferred treatment options but poor tolerance to toxins makes its use prohibitive. In this study, efforts have been made to understand the key parameters for developing anaerobic reactor, resilient to cyanide toxicity. A laboratory scale anaerobic batch reactor was set up to treat cyanide containing wastewater. The reactor was inoculated with anaerobic sludge obtained from a wastewater treatment plant and fresh cow dung in the ratio of 3:1. The focus was on acclimatization and development of cyanide-degrading biomass and to understand the toxic effects of cyanide on the dynamic equilibrium between various microbial groups. The sludge exposed to cyanide was found to have higher bacterial diversity than the control. It was observed that certain hydrogenotrophic methanogens and bacterial groups were able to grow and produce methane in the presence of cyanide. Also, it was found that hydrogen utilizing methanogens were more cyanide tolerant than acetate utilizing methanogens. So, effluents from various industries like electroplating, coke oven plant, petroleum refining, explosive manufacturing, and pesticides industries which are having high concentrations of cyanide can be treated by favoring the growth of the tolerant microbes in the reactors. It will provide much better treatment efficiency by overcoming the inhibitory effects of cyanide to certain extent. PMID:27179200

  20. 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

  1. Feasibility of treating partially soluble wastewater in anaerobic sequencing batch biofilm reactor (ASBBR) with mechanical stirring.

    Science.gov (United States)

    Pinho, Samantha Cristina; Ratusznei, Suzana Maria; Rodrigues, José Alberto Domingues; Foresti, Eugenio; Zaiat, Marcelo

    2005-03-01

    This work reports on the treatment of partially soluble wastewater in an anaerobic sequencing batch biofilm reactor, containing biomass immobilized on polyurethane matrices and stirred mechanically. The results showed that agitation provided optimal mixing and improved the overall organic matter consumption rates. The system showed to be feasible to enhance the treatment of partially soluble wastewaters. PMID:15491835

  2. 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.

  3. Performance and methanogenic community of rotating disk reactor packed with polyurethane during thermophilic anaerobic digestion

    International Nuclear Information System (INIS)

    A newly developed anaerobic rotating disk reactor (ARDR) packed with polyurethane was used in continuous mode for organic waste removal under thermophilic (55 oC) anaerobic conditions. This paper reports the effects of the rotational speed on the methanogenic performance and community in an ARDR supplied with acetic acid synthetic wastewater as the organic substrate. The best performance was obtained from the ARDR with the rotational speed (ω) of 30 rpm. The average removal of dissolved organic carbon was 98.5%, and the methane production rate was 393 ml/l-reactor/day at an organic loading rate of 2.69 g/l-reactor/day. Under these operational conditions, the reactor had a greater biomass retention capacity and better reactor performance than those at other rotational speeds (0, 5 and 60 rpm). The results of 16S rRNA phylogenetic analysis indicated that the major methanogens in the reactor belonged to the genus Methanosarcina spp. The results of real-time polymerase chain reaction (PCR) analysis suggested that the cell density of methanogenic archaea immobilized on the polyurethane foam disk could be concentrated more than 2000 times relative to those in the original thermophilic sludge. Scanning electron microphotographs showed that there were more immobilized microbes at ω of 30 rpm than 60 rpm. A rotational speed on the outer layer of the disk of 6.6 m/min could be appropriate for anaerobic digestion using the polyurethane ARDR

  4. Performance evaluation of a novel anaerobic-anoxic sludge blanket reactor for biological nutrient removal treating municipal wastewater.

    Science.gov (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Herrero, María; Tejero, Iñaki

    2016-06-01

    A novel anaerobic-anoxic sludge blanket reactor, AnoxAn, unifies the non-aerated zones of the biological nutrient removal treatment train in a single upflow reactor, aimed at achieving high compactness and efficiency. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. This contribution presents the performance evaluation of the novel reactor in the removal of organic matter and nutrients from municipal wastewater, coupled with an aerobic hybrid MBR. The overall system achieved total nitrogen and phosphorus removal with average efficiencies of 75% and 89%, respectively. Separate anoxic and anaerobic conditions were maintained in AnoxAn, allowing anaerobic phosphate release and nearly complete anoxic denitrification in the single reactor operating with an HRT of 4.2h. Biomass was retained in the reactor achieving TSS concentration up to 10gL(-1) and partial hydrolysis of influent particulate organic matter. PMID:26970922

  5. Influence of inoculum on performance of anaerobic reactors for treating municipal solid waste.

    Science.gov (United States)

    Lopes, Wilton Silva; Leite, Valderi Duarte; Prasad, Shiva

    2004-09-01

    The influence of bovine rumen fluid inoculum during anaerobic treatment of the organic fraction of municipal solid waste (MSW) was studied in this work. The parameters adopted for evaluation were the biostabilization constant of total volatile solids (TVS) and the biostabilization time of the chemical oxygen demand (COD) applied to the reactors. The work was realized in four anaerobic batch reactors of 20 l capacity each, during a period of 365 days. The proportions between MSW/inoculum loaded in the reactors were Reactor A (100%/0%), Reactor B (95%/5%), Reactor C (90%/10%) and Reactor D (85%/15%). The necessary time for biostabilization of half of the applied COD was 459, 347, 302 and 234 days and the average of methane concentration in the biogas produced was 3.6%, 13.0%, 25.0% and 42.6% for Reactors A, B, C and D, respectively. The data obtained affirm that the inoculum used substantially improved the performance of the process. PMID:15182832

  6. Integrated anaerobic-aerobic fixed-film reactor for slaughterhouse wastewater treatment.

    Science.gov (United States)

    Del Pozo, R; Diez, V

    2005-03-01

    An integrated anaerobic-aerobic fixed-film pilot-scale reactor with arranged media was fed during 166 days with slaughterhouse wastewater. Operation temperature was 25 degrees C and the anaerobic-aerobic volume ratio was decreased from 4:1 to 3:2 and finally to 2:3. Overall organic matter removal efficiencies of 93% were achieved for an average organic loading rate of 0.77 kg COD/m3 d, and nitrogen removal efficiencies of 67% were achieved for nitrogen loading rates of 0.084 kg N/m3 d. The high internal recirculation associated to the air-lift effect linked to the aeration of a part of the reactor section caused high mixing between the anaerobic and aerobic zones, so that most organic matter was removed aerobically. The nitrification process achieved an efficiency of 91% for nitrogen loads of 0.15 kg N/m3 d when the anaerobic-aerobic volume ratio was 2:3 and was limited by dissolved oxygen concentration below 3 mg/l. The influence of the heterotrophic biomass growing in the outer biofilm was checked. Denitrification only implied the 12-34% of the total nitrogen removal and was limited by dissolved oxygen concentration in the anaerobic zone above 0.5 mg/l caused by the mixing regime. Most removed nitrogen was employed in synthesis of heterotrophic bacteria. PMID:15766966

  7. 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

    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 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....... 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...

  8. 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.

  9. 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.

  10. 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.

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

    OpenAIRE

    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 (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for CODtotal; 51-73% for CODcolloidal and 20-55% for CODsoluble was found at a total HRT of 5-10 h, respectively. By prolonging the HRT...

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

    OpenAIRE

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

    2014-01-01

    A coupling process of anaerobic methanogenesis and electromethanogenesis was proposed to treat high organic load rate (OLR) wastewater. During the start-up stage, acetate removal efficiency of the electric-biological reactor (R1) reached the maximization about 19 percentage points higher than that of the control anaerobic reactor without electrodes (R2), and CH4 production rate of R1 also increased about 24.9% at the same time, while additional electric input was 1/1.17 of the extra obtained ...

  13. A granulation model using diosgenin wastewater in an upflow anaerobic sludge blanket reactor

    Institute of Scientific and Technical Information of China (English)

    Jianguo BAO; Hui LIU; Yanxin WANG; Lijun ZHANG

    2009-01-01

    An enhanced start-up of an upfiow anaerobic sludge blanket (UASB) reactor for diosgenin wastewater treatment was designed and experimentally tested. Gran-ular sludge was formed on day 35 in the reactor with high concentrations of chloride (4000-7000 mg/L) and COD (5000-13000mg/L) as substrate. A new model for the granulation was proposed which divides the formation of anaerobic granules into six consecutive stages; they include semi-embryonic granule formation, embryonic granule formation, single-nucleus granule formation, multi-nuclei granule formation, granule growth and granule maturation. A model of the granule structure was also proposed based on scanning electron microscope observation. The microspores occurring on the surface and further leading into the interior of the granules were considered as the channels and the passage of the materials and the products of the microorganisms' metabolism inside the granules.

  14. 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

    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......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...... 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...

  15. 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.

  16. Anaerobic Removal of Ammonia Nitrogen by an Autotrophic Reactor with Fixed Film Opering in a Sequential Batch

    OpenAIRE

    Murilo C. Lucas; José H. A. Vasconcelos; Francisco Javier Cuba Téran; Carla Eloísa Diniz dos Santos

    2010-01-01

    This study presents results of ammonia nitrogen oxidation in absence of molecular oxygen. They were obtained after the operation of a sequential batch anaerobic reactor with fixed film. After the inoculation with sludge from an anaerobic stabilization pond of a slaughterhouse wastewater treatment plant, the reactor was fed with a synthetic culture media, as described by Martins (2007), in order to establish ideal conditions for growth and development of Anammox culture. The duration of the ba...

  17. Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater

    International Nuclear Information System (INIS)

    The objective of this study was to examine the effects of organic loading rate and hydraulic retention time on volatile fatty acid composition and treatment efficiency of high rate thermophilic anaerobic contact reactor (TACR) treating potato-chips wastewaters. The operational performance of TACR was monitored from start-up by assessing chemical oxygen demand (COD) removal efficiencies, volatile fatty acid (VFA) production and biogas composition. The reactor was studied at different organic loading rates (OLRs) ranging from 0.6 to 8 kg COD/m3 d. The COD removal efficiencies were found to be 86-97% and the methane percentage of the biogas produced was 68-89% during the OLRs studied. The approximate methane yield was found to be 0.42 m3 CH4/kg CODremoved. The major intermediate products of anaerobic digestion were acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, iso-caproate and caproate. The use of thermophilic anaerobic contact reactor offers a sustainable technology for the treatment of potato-chips wastewaters since high COD removal efficiencies and high methane percentage in the biogas produced can be attained even at high OLRs.

  18. Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sentuerk, E.; Ince, M. [Gebze Institute of Technology, Department of Environmental Engineering, Gebze, 41400, Kocaeli (Turkey); Onkal Engin, G., E-mail: guleda@gyte.edu.tr [Gebze Institute of Technology, Department of Environmental Engineering, Gebze, 41400, Kocaeli (Turkey)

    2010-04-15

    The objective of this study was to examine the effects of organic loading rate and hydraulic retention time on volatile fatty acid composition and treatment efficiency of high rate thermophilic anaerobic contact reactor (TACR) treating potato-chips wastewaters. The operational performance of TACR was monitored from start-up by assessing chemical oxygen demand (COD) removal efficiencies, volatile fatty acid (VFA) production and biogas composition. The reactor was studied at different organic loading rates (OLRs) ranging from 0.6 to 8 kg COD/m{sup 3} d. The COD removal efficiencies were found to be 86-97% and the methane percentage of the biogas produced was 68-89% during the OLRs studied. The approximate methane yield was found to be 0.42 m{sup 3} CH{sub 4}/kg COD{sub removed}. The major intermediate products of anaerobic digestion were acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, iso-caproate and caproate. The use of thermophilic anaerobic contact reactor offers a sustainable technology for the treatment of potato-chips wastewaters since high COD removal efficiencies and high methane percentage in the biogas produced can be attained even at high OLRs.

  19. 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.

  20. Effect of internal recirculation velocity in an anaerobic sequencing batch reactor (ASBR

    Directory of Open Access Journals (Sweden)

    G. Z. Maurina

    2014-12-01

    Full Text Available This paper discusses the effect of different internal recirculation velocities on the mixture and shear stress on the flocs in an anaerobic sequencing batch reactor (ASBR. Thus, simulations are performed using a computational fluid dynamics (CFD tool to evaluate this dependency. The analysis of velocities and turbulent kinetic energy indicates that the highest flow evaluated (0.003 m³/s results in better mixing within the reactor. However, care must be taken with the recycling pipe size, in order to maintain the shear stress inside the range of optimal values.

  1. Performance of anaerobic sequencing batch reactors (pilot-scale) in domestic sewage treatment

    OpenAIRE

    Eugenio Foresti; Marcelo Zaiat; Arnaldo Sarti

    2005-01-01

    This study shows the results obtained during 70 days using four pilot scale anaerobic sequencing batch reactors, for sewage system treatment of the campus of the University of São Paulo in São Carlos – SP. Each reactor system with 1.2 m³ of total volume, was designed for the treatment of 1.95 m³d³ of domestic sewage, with geometrical conceptions (ratio H-height/D-diameter), mechanical conceptions (mechanical mixing or liquid re-circulation) and different biomass retention type. Three of them ...

  2. 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. PMID:24065871

  3. 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.

  4. 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. PMID:24923659

  5. Hydraulics of laboratory and full-scale upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Batstone, D J; Hernandez, J L A; Schmidt, J E

    2005-08-01

    Laboratory-scale upflow anaerobic sludge blanket (UASB) reactors are often used as test platforms to evaluate full-scale applications. However, for a given volume specific hydraulic loading rate and geometry, the gas and liquid flows increase proportionally with the cube root of volume. In this communication, we demonstrate that a laboratory-scale reactor had plug-flow hydraulics, while a full-scale reactor had mixed flow hydraulics. The laboratory-scale reactor could be modeled using an existing biochemical model, and parameters identified, but because of computational speed with plug-flow hydraulics, mixed systems are instead recommended for parameter identification studies. Because of the scaling issues identified, operational data should not be directly projected from laboratory-scale results to the full-scale design. PMID:15977253

  6. 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.

  7. 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

    Dechlorination of tetrachloroethene, also known as perchloroethylene (PCE), was investigated in an upflow anaerobic sludge blanket (UASB) reactor after incorporation of the strictly anaerobic, reductively dechlorinating bacterium Dehalospirillum multivorans into granular sludge. This reactor...... 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.......5 mM acetate and were operated under sterile conditions. In the test reactor, an average of 93% (mole/mole) of the effluent chloroethenes was dichloroethene (DCE), compared to 99% (mole/mole) in the Ri reactor. The R2 reactor, with no inoculation, produced only trichloroethene (TCE), averaging 43...

  8. 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

    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...... (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...

  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. 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...... 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...

  11. 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 0.070mLCH4/mL reactor/day, which is 2.59times higher than AD control reactor (0.027m(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 0.247mLCH4/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. PMID:26913643

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

    International Nuclear Information System (INIS)

    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 mgNH4–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

  13. 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.

  14. 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. PMID:22097038

  15. 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. PMID:27088208

  16. Anaerobic reactor/high rate pond combined technology for sewage treatment in the Mediterranean area.

    Science.gov (United States)

    El Hafiane, F; El Hamouri, B

    2005-01-01

    Two high-rate, anaerobic/aerobic units were used to treat the sewage of the Institut Agronomique st Vétérinaire Hassan II (Morocco) campus in a 1,100 m2-plant designed for 1,500 e.p. and receiving 63 m3 per day. The anaerobic pre-treatment consisted of a two-step up-flow anaerobic reactor (TSUAR) comprising two reactors and one external settler all in series. The aerobic line, or post-treatment, consisted of a high-rate algal pond (HRAP) and one maturation pond in series. The system totalized a hydraulic retention time (HRT) of 9 days. A gravel filter (GF) was constructed behind the TSUAR to trap low-density particles. The TSUAR removed 80% of COD and 90% of SS within 48 h. Solids retention time in the reactors averaged 32 d with a specific sludge production of 0.28 g SS g(-1) COD removed. Almost 93% of the sludge evacuated from the settler was stabilized. Specific biogas production from both reactors was 0.25m3 kg(-1) COD removed. Used in this configuration, the HRAP lost its BOD removal activity and increased its nutrients and pathogens removal capabilities (tertiary treatment). Results showed that 85% of total nitrogen and 48% of total phosphorus were removed by the HRAP. Land area requirement of this combination was less than 1 m2 per capita and filtered final effluent was of excellent quality (COD, 82 mg/l; TKN, 8.3 mg/l; total P, 2.7 mg/l, faecal coliforms, 2.4 10(3)/100 ml and zero helminths eggs). PMID:16114674

  17. 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...

  18. 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%.

  19. 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

    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 m...... and buffer concentration. The highest hydrogen production rate of 32.2 mL/L/d and YH2 of 1.43 mol-H2/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....... 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...

  20. Anaerobic Treatment of Concentrated Black Water in a UASB Reactor at a Short HRT

    Directory of Open Access Journals (Sweden)

    Cees J. N. Buisman

    2010-02-01

    Full Text Available This research describes the feasibility of applying a UASB reactor for the treatment of concentrated black (toilet water at 25 °C. On average 78% of the influent load of COD at an HRT of 8.7 days was removed. Produced methane can be converted to 56 MJ/p/y as electricity and 84 MJ/p/y as heat by combined heat and power (CHP. Minimum reactor volume at full scale was calculated to be 63L per person (for black water containing 16 gCOD/L produced at 5 L/p/d and this is more than two times smaller than other type of reactors for anaerobic treatment of concentrated black water.

  1. 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

    OpenAIRE

    Sumate Chaiprapat; Poonsuk Prasertsan; Piyarat Boonsawang; Ronnachai Chaisri

    2007-01-01

    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 produc...

  2. 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.

  3. Optimization and control of a novel upflow anaerobic solid-state (UASS) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mumme, J.; Linke, B. [Leibniz Inst. for Agricultural Engineering, Potsdam (Germany); Tolle, R. [Humboldt Univ., Berlin (Germany). Dept. of Biosystems Technology

    2010-07-01

    Optimization and control strategies for a newly developed upflow anaerobic solid-state (UASS) reactor equipped with liquor recirculation were investigated. The UASS reactor converts solid biomass into biogas while the particulate organic matter (POM) ascends in the form of a solid-state bed (SSB) driven by the adherence of self-produced micro gas bubbles. Performance data and technical characteristics were obtained from a technical scale semi-automatic 400 L UASS reactor that operated for 117 days with maize silage under thermophilic conditions at 55 degrees C. The process liquor was continuously recirculated through separate methanogenic reactors in order to prevent an accumulation of volatile fatty acids. Emphasis was placed on determining the gas and metabolite production. The volatile solids (VS) loading rate was fixed at 5 g per litre per day. The methane production rate of the UASS reactor stabilized between 1.5 and 2.0 L per litre per day. The average volatile solids (VS) methane yield of the maize silage was 380 L per kg. The liquor exchange was found to play an important role in the performance and stability of the digestion process. Although low exchange rates can cause process failure by acidification, high exchange rates have the risk of clogging inside the SSB. It was concluded that the UASS reactor is a viable solution for the digestion of various organic matter.

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

    OpenAIRE

    Gürtekin, Engin; Nusret ŞEKERDAĞ

    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.

  5. 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.

  6. The Temperature Influence to Biogas Production on Anaerobic Reactor at Ponggol Singapore

    International Nuclear Information System (INIS)

    Temperature is one of the important factor which is influence the fermentation process, but in tropical country like Singapore or Indonesia heating process is not necessary, so it is needed to observe the benefit of heater installation. The observation of temperature influence to biogas production of 1500 m3, Totally mix anaerobic reactor with hydraulic retention time 10 days with and without heating process is 13% higher than without heating process. Gas quality is not influence the process during the observation time, while the degradation of total volatile solid with heating process is 75.8% and without heating process is 57.3%. (author)

  7. Performance of anaerobic fixed film down-flow reactor for spent wash treatment

    International Nuclear Information System (INIS)

    The performance of a bench scale 'anaerobic fixed-film down-flow bioreactor' with glass bead as a packing material for treatment of high strength wastewater (spent wash) in terms of percent Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) removal at various temperatures has been studied. The reactor is operated at temperatures ranging from 35 deg. C to 51 deg. for hydraulic retention time (HRT) of 15 days. For this hydraulic retention time, experimental results show that COD removal is 60-64.8 % and BOD removal is 65.3 - 70%. The maximum percent COD and BOD removal is observed at 41 deg. C. (author)

  8. Start-up phase of an anaerobic full-scale farm reactor - Appearance of mesophilic anaerobic conditions and establishment of the methanogenic microbial community.

    Science.gov (United States)

    Goux, Xavier; Calusinska, Magdalena; Fossépré, Marie; Benizri, Emile; Delfosse, Philippe

    2016-07-01

    The goal of this study was to investigate how the microbial community structure establishes during the start-up phase of a full-scale farm anaerobic reactor inoculated with stale and cold cattle slurry. The 16S/18S high-throughput amplicon sequencing results showed an increase of the bacterial, archaeal and eukaryotic diversity, evenness and richness during the settlement of the mesophilic anaerobic conditions. When a steady performing digestion process was reached, the microbial diversity, evenness and richness decreased, indicating the establishment of a few dominant microbial populations, best adapted to biogas production. Interestingly, among the environmental parameters, the temperature, alkalinity, free-NH3, total solids and O2 content were found to be the main drivers of microbial dynamics. Interactions between eukaryotes, characterized by a high number of unknown organisms, and the bacterial and archaeal communities were also evidenced, suggesting that eukaryotes might play important roles in the anaerobic digestion process. PMID:27099947

  9. Scandinavian baffle boiler design revisited

    OpenAIRE

    Stepanov Borivoj Lj.; Pešenjanski Ivan K.; Spasojević Momčilo Đ.

    2015-01-01

    The aim of this paper is to examine whether the use of baffles in a combustion chamber, one of the well-known low-cost methods for the boiler performance improvement, can be enhanced. Modern day tools like computational fluid dynamics were not present at the time when these measures were invented, developed and successfully applied. The objective of this study is to determine the influence of location and length of a baffle in a furnace, for different mass ...

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

    International Nuclear Information System (INIS)

    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/TiO2 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.

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

    Science.gov (United States)

    Liao, Xiaofeng; Zhu, Shuangyan; Zhong, Delai; Zhu, Jingping; Liao, Li

    2014-11-01

    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 mgNH4-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. PMID:25062938

  12. 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).

  13. Pyrosequencing reveals microbial community profile in anaerobic bio-entrapped membrane reactor for pharmaceutical wastewater treatment.

    Science.gov (United States)

    Ng, Kok Kwang; Shi, Xueqing; Ong, Say Leong; Ng, How Yong

    2016-01-01

    In this study, pharmaceutical wastewater with high salinity and total chemical oxygen demand (TCOD) was treated by an anaerobic membrane bioreactor (AnMBR) and an anaerobic bio-entrapped membrane reactor (AnBEMR). The microbial populations and communities were analyzed using the 454 pyrosequencing method. The hydraulic retention time (HRT), membrane flux and mean cell residence time (MCRT) were controlled at 30.6h, 6L/m(2)h and 100d, respectively. The results showed that the AnBEMR achieved higher TCOD removal efficiency and greater biogas production compared to the AnMBR. Through DNA pyrosequencing analysis, both the anaerobic MBRs showed similar dominant groups of bacteria and archaea. However, phylum Elusimicrobia of bacteria was only detected in the AnBEMR; the higher abundance of dominant archaeal genus Methanimicrococcus found in the AnBEMR could play an important role in degradation of the major organic pollutant (i.e., trimethylamine) present in the pharmaceutical wastewater. PMID:26577579

  14. 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.

  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. 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 feeding...... patterns, dilution and addition of adsorbents, in order to determine the most appropriate strategy for fast recovery of the reactor activity in manure based plants inhibited by LCFA. Dilution with active inoculum for increasing the biomass/LCFA ratio, or addition of adsorbents for adsorbing the LCFA...... and reducing the bioavailable LCFA concentration, were found to be the best recovery strategies, improving the recovery time from 10 to 2 days, in semi-continuously fed systems. Moreover, acclimatization was introduced by repeated inhibition and process recovery. The subsequent exposure of the anaerobic...

  17. 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.

  18. Hydrogen production from anaerobic treatment of vinasse using a UASB reactor

    International Nuclear Information System (INIS)

    Production of hydrogen in a UASB reactor is assessed in the laboratory through anaerobic fermentation of vinasses. Physico-chemical characterization of vinasse was made, through which it was determined that the same has an acid pH, high concentration of dissolved solids, low amount of total suspended solids and high organic load; likewise, potassium, nitrogen, calcium and iron contained within of the macro and micronutrients with higher concentrations, while copper and zinc are found in low concentrations. All these features have made the vinasse a substrate feasible for hydrogen fermentative production. The sulfate was found as the second compound in higher concentration, which can promote the growth of sulfate-reducing bacteria, which consume H2 and generate hydrogen sulfide (H2S). Heat treatment was conducted to the anaerobic sludges in a water bath at 100 degrees for 30 minutes, which was achieved inhibit the growth of methanogenic bacteria. Likewise, total nonviable or viable matter growth curves were generated, with which it was determined that the exponential growth phase of bacteria in mixed culture thermally pretreated was found between 20 and 120 h. A CSTR reactor was used to decrease the time of formation of Hydrogen Producing Granules (GPH), which has resulted successful. Granules with an average size of 1,28 mm long and 1,18 mm wide after 7 days of operation were obtained. Under mesophilic conditions, operating pH of about 5,50 and substrate concentration of 20,000 mg COD/L, the hydrogen quantity produced in the UASB reactor was influenced by Hydraulic retention time (HRT). HRT for 12 hours was obtained a maximum of 2,31 mL/h of H2 (0,789 mL/h/Lreaccion) whereas for HRT of 6 hours the maximum amount of hydrogen obtained has been 12,0 mL/h (13,4 mL/h/Lreaction); however, without possibility to assert that the average values of these variables has been statistically different. After 45 days of operation GHP were achieved with an average size of 0,50 mm

  19. 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.

  20. A robust fuzzy-logic-based controller for bio-methane production in anaerobic fixed-film reactors

    OpenAIRE

    Robles Martinez, Angel; Latrille, Eric; Ruano, M.V.; Steyer, Jean-Philippe

    2015-01-01

    The main objective of this work was to develop a robust controller for bio-methane production in continuous anaerobic fixed-bed reactors. 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 raw winery wastewater. The proposed controller regulated the flow-rate of wastewater entering the system as a function of the gaseous outflow rate of methane and the effluent Volatile Fatty Acids (VFA) concentratio...

  1. Stress evaluation of baffle former bolt for IASCC failure prediction

    International Nuclear Information System (INIS)

    Baffle structure in PWRs Reactor is quite important assembly for the core safety, and Baffle Former Bolts (BFBs) are fastener members for maintaining Baffle structure. It has been reported worldwide that some of BFBs were cracked due to IASCC (Irradiation Assisted Stress Corrosion Cracking) because BFBs are located at core region under severe environments, high neutron flux, high temperature and high stress. According to the material studies of IASCC on austenitic stainless steel, a crack initiation of IASCC is strongly related with the stress and the neutron fluence. For this reason, it is very important for IASCC failure prediction to simulate the stress of BFBs. However, the stress of BFBs are considered to be influenced by several factors and to be changed complexly as operational time increases, by irradiation creep of Bolt itself, swelling of Baffle structure, and so on. Therefore, it is difficult to estimate the stress histories of BFBs (Bolt stress as a function of operational time) precisely. Then, the author has developed the calculation method of the stress histories of BFBs considering irradiation effects (swelling and irradiation creep). In this method, the stress histories of BFBs are calculated by combining two kinds of FE models, Global model (modeled whole Baffle structure which consists of Baffle plates, Former plates and Core Barrel) and Local model (modeled around BFB finely). The whole Baffle structure deformation changes as a function of heat, swelling and irradiated creep are calculated by Global model, and the stress histories of BFBs are calculated by Local model using the outputs (deformations on driving nodes) of Global model. In the FE analysis of Local model, the stress of BFBs are calculated considering irradiation effects and elastic-plastic characteristics depending on neutron fluence, so this method enables to calculate precisely the stress of extreme small area of BFBs surface. This paper shows the outline of the calculation method

  2. Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies

    KAUST Repository

    Shoener, B. D.

    2014-01-01

    The negative energy balance of wastewater treatment could be reversed if anaerobic technologies were implemented for organic carbon oxidation and phototrophic technologies were utilized for nutrient recovery. To characterize the potential for energy positive wastewater treatment by anaerobic and phototrophic biotechnologies we performed a comprehensive literature review and analysis, focusing on energy production (as kJ per capita per day and as kJ m-3 of wastewater treated), energy consumption, and treatment efficacy. Anaerobic technologies included in this review were the anaerobic baffled reactor (ABR), anaerobic membrane bioreactor (AnMBR), anaerobic fluidized bed reactor (AFB), upflow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), microbial electrolysis cell (MEC), and microbial fuel cell (MFC). Phototrophic technologies included were the high rate algal pond (HRAP), photobioreactor (PBR), stirred tank reactor, waste stabilization pond (WSP), and algal turf scrubber (ATS). Average energy recovery efficiencies for anaerobic technologies ranged from 1.6% (MFC) to 47.5% (ABR). When including typical percent chemical oxygen demand (COD) removals by each technology, this range would equate to roughly 40-1200 kJ per capita per day or 110-3300 kJ m-3 of treated wastewater. The average bioenergy feedstock production by phototrophic technologies ranged from 1200-4700 kJ per capita per day or 3400-13000 kJ m-3 (exceeding anaerobic technologies and, at times, the energetic content of the influent organic carbon), with usable energy production dependent upon downstream conversion to fuels. Energy consumption analysis showed that energy positive anaerobic wastewater treatment by emerging technologies would require significant reductions of parasitic losses from mechanical mixing and gas sparging. Technology targets and critical barriers for energy-producing technologies are identified, and the role of integrated anaerobic and phototrophic

  3. Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies.

    Science.gov (United States)

    Shoener, B D; Bradley, I M; Cusick, R D; Guest, J S

    2014-05-01

    The negative energy balance of wastewater treatment could be reversed if anaerobic technologies were implemented for organic carbon oxidation and phototrophic technologies were utilized for nutrient recovery. To characterize the potential for energy positive wastewater treatment by anaerobic and phototrophic biotechnologies we performed a comprehensive literature review and analysis, focusing on energy production (as kJ per capita per day and as kJ m(-3) of wastewater treated), energy consumption, and treatment efficacy. Anaerobic technologies included in this review were the anaerobic baffled reactor (ABR), anaerobic membrane bioreactor (AnMBR), anaerobic fluidized bed reactor (AFB), upflow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), microbial electrolysis cell (MEC), and microbial fuel cell (MFC). Phototrophic technologies included were the high rate algal pond (HRAP), photobioreactor (PBR), stirred tank reactor, waste stabilization pond (WSP), and algal turf scrubber (ATS). Average energy recovery efficiencies for anaerobic technologies ranged from 1.6% (MFC) to 47.5% (ABR). When including typical percent chemical oxygen demand (COD) removals by each technology, this range would equate to roughly 40-1200 kJ per capita per day or 110-3300 kJ m(-3) of treated wastewater. The average bioenergy feedstock production by phototrophic technologies ranged from 1200-4700 kJ per capita per day or 3400-13 000 kJ m(-3) (exceeding anaerobic technologies and, at times, the energetic content of the influent organic carbon), with usable energy production dependent upon downstream conversion to fuels. Energy consumption analysis showed that energy positive anaerobic wastewater treatment by emerging technologies would require significant reductions of parasitic losses from mechanical mixing and gas sparging. Technology targets and critical barriers for energy-producing technologies are identified, and the role of integrated anaerobic and

  4. [Achievement of Sulfate-Reducing Anaerobic Ammonium Oxidation Reactor Started with Nitrate-Reducting Anaerobic Ammonium Oxidation].

    Science.gov (United States)

    Liu, Zheng-chuan; Yuan, Lin-jiang; Zhou, Guo-biao; Li, Jing

    2015-09-01

    The transformation of nitrite-reducing anaerobic ammonium oxidation to sulfate-reducing anaerobic ammonium oxidation in an UASB was performed and the changes in microbial community were studied. The result showed that the sulfate reducing anaerobic ammonium oxidation process was successfully accomplished after 177 days' operation. The removal rate of ammonium nitrogen and sulfate were up to 58. 9% and 15. 7%, the removing load of ammonium nitrogen and sulfate were 74. 3 mg.(L.d)-1 and 77. 5 mg.(L.d)-1 while concentration of ammonium nitrogen and sulfate of influent were 130 mg.(L.d)-1 and 500 mg.(L.d)-1, respectively. The lost nitrogen and sulphur was around 2 in molar ratio. The pH value of the effluent was lower than that of the influent. Instead of Candidatus brocadia in nitrite reducing anaerobic ammonium oxidation granular sludge, Bacillus benzoevorans became the dominant species in sulfate reducing anaerobic ammonium oxidation sludge. The dominant bacterium in the two kinds of anaerobic ammonium oxidation process is different. Our results imply that the two anaerobic ammonium oxidation processes are carried out by different kind of bacterium. PMID:26717697

  5. 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。

  6. Landfill Leachate Treatment Using Hybrid Up-Flow Anaerobic Sludge Blanket (HUASB Reactor

    Directory of Open Access Journals (Sweden)

    Mohd Bharudin Ridzuan

    2013-11-01

    Full Text Available Abstract: The Effect of the development process in the country would lead the increment of the solid wastes production. Malaysia as a developing country is also could not escape from the problem in its solid waste management. An important problem that associated to landfill is the production of leachate. Leachate contains dangerous substances such as organic matters, heavy metals, Nitrogen Ammonia and other materials that could pollute underground water source. The aim of the paper was to study landfill leachate treatment efficiency using Hybrid Upflow Anaerobic Sludge Blanket (HUASB reactor in lab-scale. This research was investigate the pollutant content in landfill leachate and determines the percentage of nutrient removal. Parameters used for this research, were Biochemical Oxygen Demand (BOD, Chemical Oxygen Demand (COD, Suspended Solid (SS, Total Nitrogen (TN, and Total Phosphorus (TP. The experiments were carried out in lab scaled constructed reactor,  30 days duration which samples for test had been taken each 3 days intervals. The results showed that HUASB reactor were capable in removal several parameters. It has great ability in removal of Total Phosphorus and Suspended Solid with 90.60% and 80.70% each. The result of COD removal showed an encouraging removal graph, with average percentage removal 73.70%. Average percentage removal for BOD is 64%. Total Nitrogen was less remove nutrient with average percentage removal 50.32%. From the results, it showed that HUASB reactor capable to remove organic pollutants from landfill leachate.

  7. Scale-up and design optimisation of anaerobic immobilised cell reactors for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Melidis, P.; Georgiou, D.; Aivasidis, A. [Department of Environmental Engineering, Demokritos University of Thrace, Xanthi (Greece)

    2003-07-01

    The legitimacy of model transfer in process technology has to date found no noteworthy influence on the design and dimensioning of immobilized cell bioreactors for anaerobic wastewater treatment. The latter still takes place solely on the basis of purely empirical rather than scientific considerations. However, it is possible to carry out design dimensioning on the basis of model theory considerations founded on process technology, as the examples of the design of fixed-bed-loop reactors and that of fluidized-bed reactors demonstrate. Together with the spatial separation of fermentative acid formation and methanogenesis (through a two-stage biology with two different microbial populations), a multi-stage design of methanisation through cascade connection of fixed-bed-loop reactors (for the narrowing of the residence time distribution) has proved particularly advantageous when applied to highly loaded and complex constituted wastewater. Technical reaction investigations on appropriately configured variants showed that for a COD conversion of 80-90% (wastewater from the foodstuffs industry), the reactor volume of the two-stage methanisation cascade could be reduced by 40-50% compared to that of the simply performed methanisation stage. (author)

  8. Biomethane production from vinasse in upflow anaerobic sludge blanket reactors inoculated with granular sludge.

    Science.gov (United States)

    Barros, Valciney Gomes de; Duda, Rose Maria; Oliveira, Roberto Alves de

    2016-01-01

    The main objective of this study was to evaluate the anaerobic conversion of vinasse into biomethane with gradual increase in organic loading rate (OLR) in two upflow anaerobic sludge blanket (UASB) reactors, R1 and R2, with volumes of 40.5 and 21.5L in the mesophilic temperature range. The UASB reactors were operated for 230 days with a hydraulic detection time (HDT) of 2.8d (R1) and 2.8-1.8d (R2). The OLR values applied in the reactors were 0.2-7.5gtotalCOD (Ld)(-1) in R1 and 0.2-11.5gtotalCOD (Ld)(-1) in R2. The average total chemical oxygen demand (totalCOD) removal efficiencies ranged from 49% to 82% and the average conversion efficiencies of the removed totalCOD into methane were 48-58% in R1 and 39-65% in R2. The effluent recirculation was used for an OLR above 6gtotalCOD (Ld)(-1) in R1 and 8gtotalCOD (Ld)(-1) in R2 and was able to maintain the pH of the influent in R1 and R2 in the range from 6.5 to 6.8. However, this caused a decrease for 53-39% in the conversion efficiency of the removed totalCOD into methane in R2 because of the increase in the recalcitrant COD in the influent. The largest methane yield values were 0.181 and 0.185 (L) CH4 (gtotalCOD removed)(-1) in R1 and R2, respectively. These values were attained after 140 days of operation with an OLR of 5.0-7.5gtotalCOD (Ld)(-1) and totalCOD removal efficiencies around 70 and 80%. PMID:27289246

  9. Efficacies of inocula on the startup of anaerobic reactors treating dairy manure under stirred and unstirred conditions

    International Nuclear Information System (INIS)

    Inocula play an important role in anaerobic reactor startup by balancing the populations of Syntrophobacter and methanogens. Such balances make syntrophic metabolism thermodynamically feasible in anaerobic digestion. In this study, the effect of inocula on the performance of dairy manure digestion was investigated by analyzing the change in volatile fatty acids (VFA), total solids (TS), volatile solids (VS), specific biogas production (SGPR), and specific methane production (SPMP) as well as scanning and transmission electron micrographs. The study was performed at four treatments. Treatment one was granular sludge (GM); treatment two was non-granular sludge (SM); treatment three was mixed culture from an anaerobic lagoon (LM); while the fourth treatment (the control denoted MM) did not receive any exogenous inocula. In addition, stirred and unstirred conditions were maintained in the reactors to determine their effect on reactor startup. Performance ranking based on the SGPR and SPMP of treatments (in descending order) was: GM, SM, LM and MM under stirred conditions. Under unstirred conditions, performance ranking (also in descending order) was: SM, GM, LM, and MM. Results of the examination of microcolonies in the granular, non-granular sludge, and dairy manure suggest that syntrophic juxtaposition of methanogens and Syntrophobacter in granular inoculum was common while it was less visible in non-granular sludge, and completely absent in dairy manure. -- Highlights: → We investigated impacts of inocula on anaerobic reactor startup period. → Reactor performance was evaluated under stirred and unstirred conditions at 35 oC. → In stirred conditions, granular sludge performance was better than other inocula. → In unstirred conditions, municipal sludge performance was better than other inocula. → Anaerobic lagoon's slurry did not improve reactor performance significantly.

  10. Feasibility of a Pulsed Sequencing Batch reactor with anaerobic aggregated biomass for the treatment of low strength wastewaters

    OpenAIRE

    Brito, A. G.; Rodrigues, A.C.; Melo, L. F.

    1997-01-01

    This study concerns an assessment of a SBR operation that associates anaerobic aggregated biomass with a pulsed action during the reaction phase, a system named Pulsed Sequencing Batch Reactor (P-SBR). The system uses a diaphragm pump as a pulsator unit to increase the liquid-solid contact, in order to avoid dead zones and possible external mass transfer resistance. A preliminary study of the operation of the reactor was performed with a low strength synthetic wastewater with a COD near 1000 ...

  11. Methane Production from Solid Potatoes by a Procedure Simulating a Bench-Scale Sequencing Batch Reactor Anaerobic Process

    OpenAIRE

    Colussi, I.; Cortesi, A.; Gallo, V; Rubesa Fernandez, A. S.; Vitanza, R.

    2014-01-01

    In this study, an experimental setup for the evaluation of a two-stage anaerobic digestion has been developed: a laboratory-scale apparatus was assembled employing solid potatoes as energy crops. Two coupled 5-litre batch-fed stirred reactors, one for the hydrolytic-acidogenic step and one for the acetogenic-methanogenic step, kept at mesophilic temperature (308.1 K), were adopted. Evaluated in the first acidogenic reactor was the influence of fermentative yeast (Saccharomyces cerevisiae) on ...

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

    OpenAIRE

    L. H. P. Garbossa; K. R. Lapa; ZAIAT M.; E. Foresti

    2005-01-01

    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 ...

  13. 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

  14. 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...... was released per mg of acetate taken up on an average. In the anoxic period, 2.0 mg of PO4-P was taken up per mg of NO3-N reduced on an average. The relationship between potassium released and phosphate released in the anaerobic phase was determined to be 0.37 mg K/mg P, while the relationship between...

  15. Anaerobic treatment of sulfate-containing wastewater from distilleries

    International Nuclear Information System (INIS)

    Bioprocess evaluation of a staged arrangement of a Pulse Driven Loop Reaktor (PDLR) and a Pulsed Anaerobic Filter (PAF) using highly polluted cherry slops as industrial wastewater shows a COD removal efficiency of 80-90% at loading rates of 8-4 kg COD/(M3.d). Contamination of cherry slops by sulfate (2 g/l) and copper (150-200 mg/l) reduces COD degradation to 40-50 percent. A pulsed anaerobic baffled reactor was envisaged as a corrective tool to improve mineralisation in the presence of sulfate-rich substrates by confining sulfate reducing bacteria to the first 4 chambers of the reactor. Phasing slightly improves COD degradation yield, but is not sufficient for stable process performance. Consequently, the use of lactic acid in stead of sulfuric acid in cherry-fermentation was suggested as a preventive method to avoid sulphide-induced digester failure. (orig.)

  16. 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

    into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH4...... in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH4 concentration in the effluent decreased from higher than 0.94mM to around 0.13mM, and thus efficient recovery of CH4 from the anaerobic effluent was achieved. In the whole operational period......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...

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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. PMID:20303732

  2. 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.

  3. 厌氧生物处理技术应用研究与展望%Application and Prospect of Anaerobic Biological Treatment Technologies

    Institute of Scientific and Technical Information of China (English)

    吴鹏; 沈耀良

    2012-01-01

    综述了厌氧处理工艺应用于工业废水处理的研究进展,并对厌氧工艺与好氧工艺进行了对比,总结了厌氧工艺的特性;阐释了厌氧工艺的应用现状及未来的发展趋势,重点介绍了厌氧流化床反应器(AFBR).上流式厌氧滤池、上流式厌氧污泥床反应器(UASB),厌氧折流板反应器(ABR)、颗粒污泥膨胀床反应器(EGSB),复合厌氧反应器。%The research progress on application of anaerobic processes for industrial wastewater treatment was reviewed, and a comparison between anaerobic treatment technologies and aerobic ones was conducted. The characteristics of the anaerobic treatment technologies were summarized by illustrating current status and future tendency of their application, and introducing several major processes including anaerobic fluidised bed reactor (AFBR), upflow anaerobic sludge blanket reactor (UASB), upflow anaerobic filter, anaerobic baffled reactor (ABR), expanded granular sludge bed reactor (EGSB), hybrid anaerobic reactors, and etc.

  4. Development of Volumetric Methane Measurement Instrument for Laboratory Scale Anaerobic Reactors

    Directory of Open Access Journals (Sweden)

    Abdul Razaque Sahito

    2015-07-01

    Full Text Available In the present study, a newly developed VMMI (Volumetric Methane-Measuring Instrument for laboratory scale anaerobic reactors is presented. The VMMI is a reliable, inexpensive, easy to construct, easy to use, corrosion resistant device that does not need maintenance, can measure a wide flow range of gas at varying pressure and temperature. As per the results of the error analysis, the accuracy of the VMMI is unilateral, i.e. -6.91%. The calibration of VMMI was investigated and a linear variation was found; hence, in situ calibration is recommended for this type of instrument. As per chromatographic analysis, it absorbs almost 100% of the carbon dioxide present in the biogas, results only the methane, and thus eliminates the need of cost intensive composition analysis of biogas through gas chromatograph

  5. 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.

  6. 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

  7. Recirculation of reverse osmosis concentrate in lab-scale anaerobic and aerobic landfill simulation reactors.

    Science.gov (United States)

    Morello, Luca; Cossu, Raffaello; Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina

    2016-10-01

    Leachate treatment is a major issue in the context of landfill management, particularly in view of the consistent changes manifested over time in the quality and quantity of leachate produced, linked to both waste and landfill characteristics, which renders the procedure technically difficult and expensive. Leachate recirculation may afford a series of potential advantages, including improvement of leachate quality, enhancement of gas production, acceleration of biochemical processes, control of moisture content, as well as nutrients and microbe migration within the landfill. Recirculation of the products of leachate treatment, such as reverse osmosis (RO) concentrate, is a less common practice, with widespread controversy relating to its suitability, potential impacts on landfill management and future gaseous and leachable emissions. Scientific literature provides the results of only a few full-scale applications of concentrate recirculation. In some cases, an increase of COD and ammonium nitrogen in leachate was observed, coupled with an increase of salinity; which, additionally, might negatively affect performance of the RO plant itself. In other cases, not only did leachate production not increase significantly but the characteristics of leachate extracted from the well closest to the re-injection point also remained unchanged. This paper presents the results of lab-scale tests conducted in landfill simulation reactors, in which the effects of injection of municipal solid waste (MSW) landfill leachate RO concentrate were evaluated. Six reactors were managed with different weekly concentrate inputs, under both anaerobic and aerobic conditions, with the aim of investigating the short and long-term effects of this practice on landfill emissions. Lab-scale tests resulted in a more reliable identification of compound accumulation and kinetic changes than full-scale applications, further enhancing the development of a mass balance in which gaseous emissions and waste

  8. Efficiency influence of exogenous betaine on anaerobic sequencing batch biofilm reactor treating high salinity mustard tuber wastewater.

    Science.gov (United States)

    He, Qiang; Kong, Xiang-Juan; Chai, Hong-Xiang; Fan, Ming-Yu; Du, Jun

    2012-01-01

    When treating a composite mustard tuber wastewater with high concentrations of salt (about 20 g Cl(-) L(-1)) and organics (about 8000 mg L(-1) COD) by an anaerobic sequencing batch biofilm reactor (ASBBR) in winter, both high salinity and low temperature will inhibit the activity of anaerobic microorganisms and lead to low treatment efficiency. To solve this problem, betaine was added to the influent to improve the activity of the anaerobic sludge, and an experimental study was carried to investigate the influence of betaine on treating high salinity mustard tuber wastewater by the ASBBR. The results show that, when using anaerobic acclimated sludge in the ASBBR, and controlling biofilm density at 50% and water temperature at 8-12 degrees C, the treatment efficiency of the reactor could be improved by adding the betaine at different concentrations. The efficiency reached the highest when the optimal dosage ofbetaine was 0.5 mmol L(-1). The average effluent COD, after stable acclimation, was 4461 mg L(-1). Relative to ASBBR without adding betaine, the activity of the sludge increased significantly. Meanwhile, the dehydrogenase activity of anaerobic microorganisms and the COD removal efficiency were increased by 18.6% and 18.1%, respectively. PMID:22988630

  9. 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.

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

    International Nuclear Information System (INIS)

    Highlights: • Removals of 16 PPCPs under aerobic and anaerobic conditions were quantified. • Operation conditions (HRT, vup, 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

  11. Study of an anaerobic - aerobic reactor of alternate phases for the removal of organic matter and nutritious, nitrogen and phosphorus

    International Nuclear Information System (INIS)

    In this article the results of the behavior from a reactor to laboratory scale with half fixed and anaerobic-aerobic alternate phases, for the organic and nutritious simultaneous removal of matter is presented. The laboratory assembly it makes with two reactors, of 2,2 l (litre) of capacity each one, connected in series, low continuous feeding, and the control of a system of solenoids valves that it allowed to automatically program of anaerobic-aerobic alternate phases in each reactor. Under this outline efficiency was obtained in removal of COD (Chemical Oxygen Demand) between 88 and 92%, of phosphorus of 87% and nitrogen of 77 to 60%, and lower volumetric loads between 2,5 and 0,38 g COD/l-d. The process generates a low sludge production, presenting economic advantages in front of aerobic traditional systems and to the removal technologies of nutritious

  12. 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.

  13. Modelling of baffled stirred tanks

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, H.; Lahtinen, M. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1996-12-31

    The three-dimensional flow field of a baffled stirred tank has been calculated using four different turbulence models. The tank is driven by a Rushton-type impeller. The boundary condition for the impeller region has been given as a source term or by calculating the impeller using the sliding mesh technique. Calculated values have been compared with measured data. (author)

  14. 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 process...... water with or without stripping ammonia. Three continuously stirred tank reactors were operated at 55 degrees C with 11.4 gVS d(-1) loading rate and 15 d retention time. Total ammonia nitrogen (TAN) level in the reactor fed with recirculated water alone was spiked to 3.5 and 5.5 g-N l(-1) through...

  15. Benzene and ethylbenzene removal by denitrifying culture in a horizontal fixed bed anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gusmao, V.R.; Chinalia, F.A.; Sakamoto, I.K.; Varesche [Univ. de Sao Paulo (Brazil). Dept. de Hidraulica e Saneamento; Thiemann, O.H. [Univ. de Sao Paulo (Brazil). Inst. de Fisica de Sao Carlos

    2004-07-01

    Benzene, ethylbenzene, toluene, and xylene are toxic and are important constituents of gasoline and other petroleum fuels. These compounds are potential health hazards because of their high solubility and hence their ability to contaminate groundwater. Anaerobic immobilized biomass is a way of treating wastewater contaminated with the above compounds. The performance of a specially adapted biofilm is critical in the viability of this idea. In this investigation, an especially adapted biofilm was obtained using a denitrifying bacterial strain isolated from a slaughterhouse wastewater treatment plant. The strain was cultured in a liquid medium with added ethanol, nitrate, ethylbenzene, and benzene. To assess the viability of the strain for the purposes of degradation of ethylbenzene, and benzene two separate horizontal reactors were prepared with polyurethane foam in order to immobilize the biomass. Various concentrations of the two compounds were admitted. At high concentrations chemical oxygen demand decreased dramatically and benzene and ethylbenzene removal almost 100 per cent. DNA sequencing of the biofilm showed that Paracoccus versutus was the dominant species in the ethylbenzene reactor. 7 refs., 6 figs.

  16. Application of horizontal-flow anaerobic immobilized biomass reactor for bioremediation of acid mine drainage.

    Science.gov (United States)

    Rodriguez, R P; Vich, D V; Garcia, M L; Varesche, M B A; Zaiat, M

    2016-06-01

    The production of low-pH effluent with sulfate and metals is one of the biggest environmental concerns in the mining industry. The biological process for sulfate reduction has the potential to become a low-cost solution that enables the recovery of interesting compounds. The present study analyzed such a process in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor, employing ethanol as the carbon and energy source. Results showed that a maximal efficiency in the removal of sulfate and ethanol could only be obtained by reducing the applied sulfate load (225.1 ± 38 g m(-3) d(-1)). This strategy led to over 75% of chemical oxygen demand (COD) and sulfate removal. Among the COD/SO4(2-) studied ratios, 0.67 showed the most promising performance. The effluent's pH has naturally remained between 6.8 and 7.0 and the complete oxidation of the organic matter has been observed. Corrections of the influent pH or effluent recirculation did not show any significant effect on the COD and sulfate removal efficiency. Species closely related to strains of Clostridium sp. and species of Acidaminobacter hydrogenomorfans and Fusibacter paucivorans that can be related to the process of sulfate reduction were found in the HAIB reactors when the initial pH was 5 and the COD/SO4(2-) ratio increased to 1.0. PMID:27280606

  17. 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.

  18. Performances and microbial features of an aerobic packed-bed biofilm reactor developed to post-treat an olive mill effluent from an anaerobic GAC reactor

    Directory of Open Access Journals (Sweden)

    Marchetti Leonardo

    2006-04-01

    Full Text Available Abstract Background Olive mill wastewater (OMW is the aqueous effluent of olive oil producing processes. Given its high COD and content of phenols, it has to be decontaminated before being discharged. Anaerobic digestion is one of the most promising treatment process for such an effluent, as it combines high decontamination efficiency with methane production. The large scale anaerobic digestion of OMWs is normally conducted in dispersed-growth reactors, where however are generally achieved unsatisfactory COD removal and methane production yields. The possibility of intensifying the performance of the process using a packed bed biofilm reactor, as anaerobic treatment alternative, was demonstrated. Even in this case, however, a post-treatment step is required to further reduce the COD. In this work, a biological post-treatment, consisting of an aerobic biological "Manville" silica bead-packed bed aerobic reactor, was developed, tested for its ability to complete COD removal from the anaerobic digestion effluents, and characterized biologically through molecular tools. Results The aerobic post-treatment was assessed through a 2 month-continuous feeding with the digested effluent at 50.42 and 2.04 gl-1day-1 of COD and phenol loading rates, respectively. It was found to be a stable process, able to remove 24 and 39% of such organic loads, respectively, and to account for 1/4 of the overall decontamination efficiency displayed by the anaerobic-aerobic integrated system when fed with an amended OMW at 31.74 and 1.70 gl-1day-1 of COD and phenol loading rates, respectively. Analysis of 16S rRNA gene sequences of biomass samples from the aerobic reactor biofilm revealed that it was colonized by Rhodobacterales, Bacteroidales, Pseudomonadales, Enterobacteriales, Rhodocyclales and genera incertae sedis TM7. Some taxons occurring in the influent were not detected in the biofilm, whereas others, such as Paracoccus, Pseudomonas, Acinetobacter and Enterobacter

  19. Immobilization patterns and dynamics of acetate-utilizing methanogens in sterile granular sludge from upflow anaerobic sludge blanket (UASB) reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1999-01-01

    Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After...... several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing ill. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only ill. mazeii S-6 immobilized, while...... the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (K-s and mu(max)) of immobilized M. concilii GP-6 or ill, mazeii S-6 compared with suspended cultures, indicating...

  20. Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1999-01-01

    Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After...... several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing ill. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only ill. mazeii S-6 immobilized, while...... the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (K-s and mu(max)) of immobilized M. concilii GP-6 or ill, mazeii S-6 compared with suspended cultures, indicating...

  1. Stabilization of fine fraction from landfill mining in anaerobic and aerobic laboratory leach bed reactors.

    Science.gov (United States)

    Mönkäre, Tiina J; Palmroth, Marja R T; Rintala, Jukka A

    2015-11-01

    Fine fraction (FF, mined landfill was stabilized in four laboratory-scale leach bed reactors (LBR) over 180 days. The aim was to study feasibility of biotechnological methods to treat FF and if further stabilization of FF is possible. Four different stabilization methods were compared and their effects upon quality of FF were evaluated. Also during the stabilization experiment, leachate quality as well as gas composition and quantity were analyzed. The methods studied included three anaerobic LBRs (one without water addition, one with water addition, and one with leachate recirculation) and one aerobic LBR (with water addition). During the experiment, the most methane was produced in anaerobic LBR without water addition (18.0 L CH4/kg VS), while water addition and leachate recirculation depressed methane production slightly, to 16.1 and 16.4 L CH4/kg VS, respectively. Organic matter was also removed via the leachate and was measured as chemical oxygen demand (COD). Calculated removal of organic matter in gas and leachate was highest in LBR with water addition (59 g COD/kg VS), compared with LBR without water addition or with leachate recirculation (51 g COD/kg VS). Concentrations of COD, ammonium nitrogen and anions in leachate decreased during the experiment, indicating washout mechanism caused by water additions. Aeration increased sulfate and nitrate concentrations in leachate due to oxidized sulfide and ammonium. Molecular weight distributions of leachates showed that all the size categories decreased, especially low molecular weight compounds, which were reduced the most. Aerobic stabilization resulted in the lowest final VS/TS (13.1%), lowest respiration activity (0.9-1.2 mg O2/g TS), and lowest methane production after treatment (0.0-0.8 L CH4/kg VS), with 29% of VS being removed from FF. Anaerobic stabilization methods also reduced organic matter by 9-20% compared with the initial amount. Stabilization reduced the quantity of soluble nitrogen in FF and did

  2. Development of a dynamic model of a Upflow Anaerobic Sludge Blanket (UASB) reactor

    International Nuclear Information System (INIS)

    'Full text:' The Upflow Anaerobic Sludge Blanket Reactor has been modeled in this paper using a semi-empirical correlation. The main objective of the modeling exercise was to examine the dynamics (hydrodynamics and transformation) of critical variables that are important for the reactor process design, performance and operation. These factors include some microbiological variables such as soluble (as COD) and biodegradable organics (as BOD), suspended solids (SS), and biomass concentration (as VSS). The hydraulic variables such as the upflow velocity of the liquid and by extension, upflow velocity of the solids and the volumetric fractions of the liquid (voidage) are also given considerations. The dynamics of external mass transfer of organics and inorganics and the transformation reactions within the reactor are modeled by five non-linear partial differential equations (PDE's), which define dependent variables in one-dimensional temporal and spatial planes, one integrand equation for the gas rate of flow and six algebraic equations that define the reactor performance (conversion rates and removal efficiencies). The PDE's are solved using backward finite differencing method. The discretized equations are computed using a simulation program that was written in the Borland C++ programming language. The model defines the dynamics of the UASB in a simplistic way but which, nonetheless, can be useful for engineering designs where the interest is in qualitative results and not quantitative outcomes. The simulation was validated with data derived from the operation of a pilot model UASB. The pilot model was operated using raw domestic wastewater as substrate, which had an average total COD of 492 mg/L, soluble COD of 172 mg/L, BOD of 220 mg/L, suspended solid of 0.235 g/L and a high sulphate content of 108 mg/L. The average nutrient concentrations were, NH3-N 20 mg/L and PO4 15 mg/L. The UASB was operated at HRT's of 10.968, 8.326 and 5.51 hours The average removal

  3. 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

  4. 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. PMID:27148733

  5. 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

    . 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......Ammonia is the major inhibitor of anaerobic digestion (AD) process leading to suboptimal utilisation of the biogas potential of the feedstocks and causing economical losses to the biogas plants. However, ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... 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...

  6. Nitrogen removal from on-site treated anaerobic effluents using intermittently aerated moving bed biofilm reactors at low temperature.

    Science.gov (United States)

    Luostarinen, Sari; Luste, Sami; Valentín, Lara; Rintala, Jukka

    2006-05-01

    On-site post-treatment of anaerobically pre-treated dairy parlour wastewater (DPWWe; 10 degrees C) and mixture of kitchen waste and black water (BWKWe; 20 degrees C) was studied in moving bed biofilm reactors (MBBR). The focus was on removal of nitrogen and of residual chemical oxygen demand (COD). Moreover, the effect of intermittent aeration and continuous vs. sequencing batch operation was studied. All MBBRs removed 50-60% of nitrogen and 40-70% of total COD (CODt). Complete nitrification was achieved, but denitrification was restricted by lack of carbon. Nitrogen removal was achieved in a single reactor by applying intermittent aeration. Continuous and sequencing batch operation provided similar nitrogen and COD removal, wherefore simpler continuous feeding may be preferred for on-site applications. Combination of pre-treating upflow anaerobic sludge blanket (UASB) -septic tank and MBBR removed over 92% of CODt, 99% of biological oxygen demand (BOD7), and 65-70% of nitrogen. PMID:16647521

  7. Bio Hydrogen Production from Pharmaceutical Waste Water Treatment by a Suspended Growth Reactor Using Environmental Anaerobic Technology

    OpenAIRE

    Krishna, R. Hema; Mohan, S. Venkata; Swamy, A. V. V. S.

    2013-01-01

    Hydrogen (H2) is considered as the future fuel. The present work on “Bio Hydrogen Production from Pharmaceutical Waste Water Treatment by a Suspended Growth Reactor Using Environmental Anaerobic Technology. This is an appreciated approach at wealth generation through value addition to wastes. The optimization process included the selection of ideal co-substrate (sucrose) and nitrogen source (DAP) to examine the feasibility of hydrogen production from industrial effluent in a 50%-50% mix...

  8. 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.

  9. 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. PMID:26750760

  10. Feasibility of a pulsed sequencing batch reactor with anaerobic aggregated biomass for the treatment of low strenght wastewaters

    OpenAIRE

    Brito, A. G.; Rodrigues, A.C.; Melo, L. F.

    1997-01-01

    This study concerns an assessment of a SBR operation that associates anaerobic aggregated biomass with a pulsed action during the reaction phase, a system named Pulsed Sequencing Batch Reactor (P-SBR). The system uses a diaphragm pump as a pulsator unit to increase the liquid-solid contact, in order to avoid dead zones and possible external mass transfer resistance. A preliminary study of the operation of the reactor was performed with a low strenght synthetic wastewater with a COD near 1000m...

  11. 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 methanogenic spp. and their activity. In biofilm systems, such as the UASB reactors the presence of the two aceticlastic methanogens could be correlated to the difference in the kinetic properties of the two species. In biogas reactors treating solid wastes, such as manure or mixture of manure and organic...... industrial waste, only Methanosarcina spp. were identified.Methanosarcina spp. isolated from different plants had different kinetics depending on their origin. Relating the reactor performance data to measurement of the activity by conventional microbiological methods gave a good indication of the microbial...

  12. 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

  13. Start-up of an anaerobic hybrid (UASB/filter) reactor treating wastewater from a coffee processing plant.

    Science.gov (United States)

    Bello-Mendoza, R; Castillo-Rivera, M F

    1998-10-01

    The ability of an anaerobic hybrid reactor, treating coffee wastewater, to achieve a quick start-up was tested at pilot scale. The unacclimatized seed sludge used showed a low specific methanogenic activity of 26.47 g CH4 as chemical oxygen demand (COD)/kg volatile suspended solids (VSS) x day. This strongly limited the reactor performance. After a few days of operation, a COD removal of 77.2% was obtained at an organic loading rate (OLR) of 1.89 kg COD/m3 x day and a hydraulic retention time (HRT) of 22 h. However, suddenly increasing OLR above 2.4 kg COD/m3 x day resulted in a deterioration in treatment efficiency. The reactor recovered from shock loads after shutdowns of 1 week. The hybrid design of the anaerobic reactor prevented the biomass from washing-out but gas clogging in the packing material was also observed. Wide variations in wastewater strength and flow rates prevented stable reactor operation in the short period of the study. PMID:16887646

  14. 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. PMID:25678409

  15. Post-treatment of anaerobic reactor effluent using coagulation/oxidation followed by double filtration.

    Science.gov (United States)

    Cavallini, Grasiele Soares; de Sousa Vidal, Carlos Magno; de Souza, Jeanette Beber; de Campos, Sandro Xavier

    2016-04-01

    This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90 % and close to 100 % removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65 % recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing. PMID:26611629

  16. High rate psychrophilic anaerobic digestion of high solids (35%) dairy manure in sequence batch reactor.

    Science.gov (United States)

    Saady, Noori M Cata; Massé, Daniel I

    2015-06-01

    Zero liquid discharge is increasingly adopted as an objective for waste treatment process. The objective of this study was to increase the feed total solids (TS) and the organic loading rate (OLR) fed to a novel psychrophilic (20°C) dry anaerobic digestion (PDAD). Duplicate laboratory-scale bioreactors were fed cow feces and wheat straw (35% TS in feed) at OLR of 6.0 g TCOD kg(-1) inoculum d(-1) during long-term operation (147 days consisting of 7 successive cycles). An overall average specific methane yield (SMY) of 151.8±7.9 N L CH4 kg(-1) VS fed with an averaged volatile solids removal of 42.4±4.3% were obtained at a volatile solids-based inoculum-to-substrate ratio (ISR) of 2.13±0.2. The operation was stable as indicated by biogas and VFAs profiles and the results were reproducible in successive cycles; a maximum SMY of 163.3±5.7 N L CH4 kg(-1) VS fed was obtained. Hydrolysis was the reaction limiting step. High rate PDAD of 35% TS dairy manure is possible in sequential batch reactor within 21 days treatment cycle length. PMID:25804501

  17. Modeling of Nitrous Oxide Production from Nitritation Reactors Treating Real Anaerobic Digestion Liquor.

    Science.gov (United States)

    Wang, Qilin; Ni, Bing-Jie; Lemaire, Romain; Hao, Xiaodi; Yuan, Zhiguo

    2016-01-01

    In this work, a mathematical model including both ammonium oxidizing bacteria (AOB) and heterotrophic bacteria (HB) is constructed to predict N2O production from the nitritation systems receiving the real anaerobic digestion liquor. This is for the first time that N2O production from such systems was modeled considering both AOB and HB. The model was calibrated and validated using experimental data from both lab- and pilot-scale nitritation reactors. The model predictions matched the dynamic N2O, ammonium, nitrite and chemical oxygen demand data well, supporting the capability of the model. Modeling results indicated that HB are the dominant contributor to N2O production in the above systems with the dissolved oxygen (DO) concentration of 0.5-1.0 mg O2/L, accounting for approximately 75% of N2O production. The modeling results also suggested that the contribution of HB to N2O production decreased with the increasing DO concentrations, from 75% at DO = 0.5 mg O2/L to 25% at DO = 7.0 mg O2/L, with a corresponding increase of the AOB contribution (from 25% to 75%). Similar to HB, the total N2O production rate also decreased dramatically from 0.65 to 0.25 mg N/L/h when DO concentration increased from 0.5 to 7.0 mg O2/L. PMID:27125491

  18. Modeling of Nitrous Oxide Production from Nitritation Reactors Treating Real Anaerobic Digestion Liquor

    Science.gov (United States)

    Wang, Qilin; Ni, Bing-Jie; Lemaire, Romain; Hao, Xiaodi; Yuan, Zhiguo

    2016-01-01

    In this work, a mathematical model including both ammonium oxidizing bacteria (AOB) and heterotrophic bacteria (HB) is constructed to predict N2O production from the nitritation systems receiving the real anaerobic digestion liquor. This is for the first time that N2O production from such systems was modeled considering both AOB and HB. The model was calibrated and validated using experimental data from both lab- and pilot-scale nitritation reactors. The model predictions matched the dynamic N2O, ammonium, nitrite and chemical oxygen demand data well, supporting the capability of the model. Modeling results indicated that HB are the dominant contributor to N2O production in the above systems with the dissolved oxygen (DO) concentration of 0.5–1.0 mg O2/L, accounting for approximately 75% of N2O production. The modeling results also suggested that the contribution of HB to N2O production decreased with the increasing DO concentrations, from 75% at DO = 0.5 mg O2/L to 25% at DO = 7.0 mg O2/L, with a corresponding increase of the AOB contribution (from 25% to 75%). Similar to HB, the total N2O production rate also decreased dramatically from 0.65 to 0.25 mg N/L/h when DO concentration increased from 0.5 to 7.0 mg O2/L. PMID:27125491

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

    International Nuclear Information System (INIS)

    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 TCOD m-3 d-1 with gradual increase to an average of 13.27 kg TCOD m-3 d-1. At stable conditions, the treatment efficiency was high with an average COD and BOD5 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 TCOD m-3 d-1. The removal efficiencies of SCOD and BOD5 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

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

    International Nuclear Information System (INIS)

    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-1 dry algae d-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

  1. 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)

  2. 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%.

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

    Science.gov (United States)

    Wang, Wen; Xie, Li; Luo, Gang; Zhou, Qi; Angelidaki, Irini

    2013-10-01

    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 (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 and hydrogenotrophic genus Methanoculleus in the liquid, which indicated that H2 were converted to methane by both direct (hydrogenotrophic methanogenesis) and indirect (homoacetogenesis+aceticlastic methanogenesis) pathways in the liquid. However, the aceticlasitic genus Methanosaeta was dominant for archaea in the biofilm on the HFM, which indicated indirect (homoacetogenesis+aceticlastic methanogenesis) H2 conversion pathway on the biofilm. PMID:23941705

  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. 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.; Schmidt, Jens Ejbye

    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...

  6. 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.

  7. 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.

  8. Study on the Characteristics of Anaerobic Granular Sludge by Internal Circulation Anaerobic Reactor%内循环厌氧反应器厌氧颗粒污泥的特性研究

    Institute of Scientific and Technical Information of China (English)

    王英

    2015-01-01

    Anaerobic granular sludge anaerobic reactor is the basis and key to the efficient and stable operation.This paper presents an improved internal circulation anaerobic reactor,to overcome the traditional internal circulation anaerobic reactor complex structure,easy to cause blockage and other shortcomings.To study the characteristics of anaerobic granular sludge,the study on the characteristics of anaerobic granular sludge to the production practice has important guiding significance.This experimental research is circulate in the modified on the basis of the stable operation of anaerobic reactor,particle size distribution of granular sludge,sludge methane-producing activity and DGGE analysis.%厌氧颗粒污泥是厌氧反应器高效稳定运行的基础和关键。试验研究利用了一种改进型的内循环厌氧反应器,克服了传统内循环厌氧反应器结构复杂易引起堵塞等缺点,对厌氧颗粒污泥的特性进行研究,研究厌氧颗粒污泥的特性对生产实践具有重要的指导意义。该试验研究是在改进型内循环厌氧反应器稳定运行的基础上,对颗粒污泥的粒径分布、污泥产甲烷活性、DGGE 等特性进行分析。

  9. 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

  10. 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.

  11. 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

  12. Tratamiento del Colorante Azo Rojo Directo 23 mediante Reactores Discontinuos Secuenciados Anaerobios/Aerobios Treatment of Direct Red 23 Azo Dye by Anaerobic/Aerobic Sequencing Batch Reactors

    Directory of Open Access Journals (Sweden)

    Fernanda Morales-Guzmán

    2009-01-01

    Full Text Available Se evaluó el tratamiento del colorante azo Rojo Directo 23 mediante un proceso anaerobio/aerobio integrado en un sólo reactor. Se utilizaron dos reactores: uno de lecho expandido con carbón activado granular como mediador redox y otro conteniendo la biomasa suspendida, ambos operados en discontinuo. Se evaluó la eficiencia del proceso mediante la reducción y transformación del colorante a aminas aromáticas totales en la fase anaerobia y la degradación de éstas en la fase aerobia. La eliminación del colorante fue por microorganismos y no por adsorción en el carbón activado granular. Las concentraciones de colorante utilizadas fueron de 25 a 100 mg L-1. En el reactor de lecho expandido la eficiencia de degradación global del colorante fue del 90 % y la eliminación de las aminas formadas fue del 100 %.The treatment of the azo dye Direct Red 23 was evaluated by an anaerobic/aerobic process done in a single reactor. Two reactors were used: one was an expanded-bed with granular activated carbon as redox mediator and the other containing the suspended biomass, both operated in batch mode. The efficiency of the process was evaluated by the reduction and transformation of the azo dye to total aromatic amines in the anaerobic phase and the degradation of these in the aerobic phase. The elimination of azo dye direct red was by microorganisms and not by adsorption in the granular activated carbon. The concentration of azo dye used was of 25 to 100 mg L-¹. In the expanded-bed reactor the removal efficiency of the dye was 90 % and the elimination of the amines formed was of 100 %.

  13. Mixed convection in a baffled grooved channel

    Indian Academy of Sciences (India)

    Aayush K Sharma; Pallab S Mahapatra; Nirmal K Manna; Koushik Ghosh

    2015-05-01

    In the present numerical work, flow structure and heat transfer characteristics are investigated in a baffled grooved channel, differentially heated from the sides. The baffle is placed vertically downward from the top wall of grooved channel geometry, with the motive of diverting outside forced flow towards the inside of the square cavity. In-house CFD code based on finite volume method has been used to solve the 2D equations of continuity, momentum and energy. The effect of change in baffle position and height is investigated in the range of Richardson numbers 0.1 to 10. For the present study, external flow from both left and right of the grooved channel are considered. A remarkable enhancement of heat transfer is observed in presence of baffle. The study has also pointed out that for optimal performance, the position and height of the baffle need to be adjusted depending on the direction of external flow.

  14. 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

    2016-07-01

    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. PMID:26652186

  15. Start-Up Characteristics of a Granule-Based Anammox UASB Reactor Seeded with Anaerobic Granular Sludge

    Directory of Open Access Journals (Sweden)

    Lei Xiong

    2013-01-01

    Full Text Available The granulation of anammox sludge plays an important role in the high nitrogen removal performance of the anammox reactor. In this study, anaerobic granular sludge was selected as the seeding sludge to start up anammox reactor in order to directly obtain anammox granules. Results showed that the anammox UASB reactor was successfully started up by inoculating anaerobic granular sludge, with substrate capacity of 4435.2 mg/(L·d and average ammonium and nitrite removal efficiency of 90.36% and 93.29%, respectively. During the start-up course, the granular sludge initially disintegrated and then reaggregated and turned red, suggesting the high anammox performance. Zn-Fe precipitation was observed on the surface of granules during the operation by SEM-EDS, which would impose inhibition to the anammox activity of the granules. Accordingly, it is suggested to relatively reduce the trace metals concentrations, of Fe and Zn in the conventional medium. The findings of this study are expected to be used for a shorter start-up and more stable operation of anammox system.

  16. The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expanded granular sludge bed reactor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The integration of methanogenesis with denitrification and anaerobic ammonium oxidation(ANAMMOX) was studied in an expanded granular sludge bed(EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, demonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9 g COD/(L@d) of COD volumetric loading rate. More than 97% to 100% of nitrite was denitrified at up to about 0.8g NO2-N/(L@d), which is 16 times higher than that in a conventional activated sludge system with nitrification/denitrification(0.05g N/((L@d). No dissimilatory reduction of nitrite to ammonium occurred in the process. However, maximum of about 40% ammonium was found to be lost. Batch tests of 15 days with sludge from the reactor showed that 100% of nitrite was denitrified completely, and about 3% of ammonium was removed when only ammonium (34.3 mg/L) and nitrite(34.3 mg/L) were added into the sludge suspension medium. Furthermore, about 15% of ammonium amounts were lost with organic COD addition. It suggested that the methanogenesis in the system could enhance ANAMMOX because of intermediate hydrogen produced during methanogenesis.

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

    International Nuclear Information System (INIS)

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

  18. Eficiência de um sistema de reatores anaeróbios no tratamento de efluentes líquidos de suinocultura =The efficiency of a sistem of anaerobic reactors treating swine wastewater.

    Directory of Open Access Journals (Sweden)

    Erlon Lopes Pereira

    2011-07-01

    Full Text Available Grande atenção tem sido dada pelos órgãos de fiscalização ambiental à produção confinada de suínos, pelo elevado potencial poluidor desse tipo de atividade. O grande desafio do suinocultor brasileiro é produzir, de forma intensiva, alimento com qualidade e ao mesmo tempo, ambientalmente sustentável. Por isso, sistemas anaeróbios de tratamento, como os que foram pesquisados neste trabalho, vêm se tornando merecedores de atenção na suinocultura em grande escala. Neste trabalho, as unidades de tratamento instaladas foram: caixa de retenção de sólidos (CRS, peneira estática (PE, tanque de acidificação e equalização (TAE, reator anaeróbio compartimentado (RAC, reator de manta de lodo (UASB e decantador. O sistema de tratamento apresentou os seguintes valores de eficiência: 91,50; 85,24; 80,46; 81,34; 79,15; 23,20 e 70,28% na remoção de DBO5, DQOtotal, sólidos totais, sólidos fixos, sólidos voláteis, fósforo total e óleos & graxas, respectivamente. Os reatores RAC e UASB operaram com tempo de detenção hidráulica de 15,4 e 9,7h, respectivamente; carga hidráulica de 1,57 m3 m-3 dia-1 para o RAC e 2,5 m3 m-3 dia-1 para o UASB; carga orgânica volumétrica de 4,46 kg m3 m-3 dia-1 para o RAC e 1,77 kg m3 m-3 dia-1 para o UASB. A produção média de biogás referente ao reator UASB, medida por meio de um gasômetro, foi de 437,08 L dia-1.Great attention has been given by environmental agencies concerning swine raising, due to the high pollutant potential of this type of activity. The challenge of Brazilian farmers is to produce, in an intensive form, high quality meat that is environmentally sustainable at the same time. Therefore, anaerobic treatment systems, such as those surveyed in this work, have gained attention in large-scale production. In this research, the installed units were: static screen (SS, equalization acidification tank (EAT, anaerobic baffled reactor (ABR, an upflow anaerobic sludge blanket reactor

  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. An integrated anaerobic--physico-chemical treatment concept for wool scouring wastewater.

    Science.gov (United States)

    Peláez, H; Gutiérrez, S; Castro, G; Hernández, A; Viñas, M

    2001-01-01

    The strong flow wastewater from a wool scouring industry is treated by a combination of anaerobic digestion and physico-chemical postreatment. Based on previous laboratory results (Gutiérrez et al., 1999), three anaerobic baffled reactors (ABR) of 300 m3 each were built, processing 60% of the strong flow of a wool scouring mill for about two years. COD and grease removal in the anaerobic reactors were 47-50% and 50-55% respectively, with an organic load between 8.9 and 6.7 kg COD/m3 d. The effluent of the anaerobic reactors was assayed with additives in an industrial decanter centrifuge. As results of these assays, all the effluent of the three reactors was sent to the decanter centrifuge after dosing additives. Overall COD and grease removal of the integrated system were 87% and 93% respectively. Dosage of coagulation-flocculation additives was optimized in a continuous flocculation device. The proposed treatment is cheaper and easier to control than others alternatives with COD removal higher than 93%. PMID:11575099

  1. Anaerobic ammonium oxidation by Nitrosomonas spp. and anammox bacteria in a sequencing batch reactor.

    Science.gov (United States)

    Lek Noophan, Pongsak; Sripiboon, Siriporn; Damrongsri, Mongkol; Munakata-Marr, Junko

    2009-02-01

    A sequencing batch reactor (SBR) was inoculated with mixed nitrifying bacteria from an anoxic tank at the conventional activated sludge wastewater treatment plant in Nongkhaem, Bangkok, Thailand. This enriched nitrifying culture was maintained under anaerobic conditions using ammonium (NH(4)(+)) as an electron donor and nitrite (NO(2)(-)) as an electron acceptor. Autotrophic ammonium oxidizing bacteria survived under these conditions. The enrichment period for anammox culture was over 100 days. Both ammonium and nitrite conversion rates were proportional to the biomass of ammonium oxidizing bacteria; rates were 0.08 g N/gV SS/d and 0.05 g N/g VSS/d for ammonium and nitrite, respectively, in a culture maintained for 3 months at 42 mg N/L ammonium. The nitrogen transformation rate at a ratio of NH(4)(+)-N to NO(2)(-)-N of 1:1.38 was faster, and effluent nitrogen levels were lower, than at ratios of 1:0.671, 1:2.18, and 1:3.05. Fluorescent in situ hybridization (FISH) was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis). The ammonium oxidizing culture maintained at 42 mg N/L ammonium was enriched for Nitrosomonas spp. (30%) over Candidati B. anammoxidans and K. stuttgartiensis (2.1%) while the culture maintained at 210 mg N/L ammonium was dominated by Candidati B. anammoxidans and K. stuttgartiensis (85.6%). The specific nitrogen removal rate of anammox bacteria (0.6 g N/g anammox VSS/d) was significantly higher than that of ammonium oxidizing bacteria (0.4 g N/g Nitrosomonas VSS/d). Anammox bacteria removed up to 979 mg N/L/d of total nitrogen (ammonium:nitrite concentrations, 397:582 mg N/L). These results suggest significant promise of this approach for application to wastewater with high nitrogen but low carbon content, such as that found in Bangkok. PMID:18423965

  2. Treatment of wastewater from coffee bean processing in anaerobic fixed bed reactors with different support materials: performance and kinetic modeling.

    Science.gov (United States)

    Fia, Fátima R L; Matos, Antonio T; Borges, Alisson C; Fia, Ronaldo; Cecon, Paulo R

    2012-10-15

    An evaluation was performed of three upflow anaerobic fixed bed reactors for the treatment of wastewater from coffee bean processing (WCP). The supports used were: blast furnace cinders, polyurethane foam and crushed stone with porosities of 53, 95 and 48%, respectively. The testing of these 139.5 L reactors consisted of increasing the COD of the influent (978; 2401 and 4545 mg L(-1)), while maintaining the retention time of 1.3 days. For the maximum COD applied, the reactor filled with foam presented removals of 80% (non-filtered samples) and 83% (filtered samples). The greater performance of the reactor filled with foam is attributed to its porosity, which promoted greater collection of biomass. From the results, it could be concluded that the reactors presented satisfactory performance, especially when using the foam as a support. Furthermore, the modified Stover-Kincannon and second order for multicomponent substrate degradation models were successfully used to develop a model of the experimental data. PMID:22609965

  3. 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

  4. Study of the diversity of microbial communities in a sequencing batch reactor oxic-settling-anaerobic process and its modified process.

    Science.gov (United States)

    Sun, Lianpeng; Chen, Jianfan; Wei, Xiange; Guo, Wuzhen; Lin, Meishan; Yu, Xiaoyu

    2016-05-01

    To further reveal the mechanism of sludge reduction in the oxic-settling-anaerobic (OSA) process, the polymerase chain reaction - denaturing gradient gel electrophoresis protocol was used to study the possible difference in the microbial communities between a sequencing batch reactor (SBR)-OSA process and its modified process, by analyzing the change in the diversity of the microbial communities in each reactor of both systems. The results indicated that the structure of the microbial communities in aerobic reactors of the 2 processes was very different, but the predominant microbial populations in anaerobic reactors were similar. The predominant microbial population in the aerobic reactor of the SBR-OSA belonged to Burkholderia cepacia, class Betaproteobacteria, while those of the modified process belonged to the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. These 3 types of microbes had a cryptic growth characteristic, which was the main cause of a greater sludge reduction efficiency achieved by the modified process. PMID:27021584

  5. 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. PMID:27039352

  6. 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.

  7. 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. PMID:25600011

  8. Mesophilic anaerobic digestion of pulp and paper industry biosludge-long-term reactor performance and effects of thermal pretreatment.

    Science.gov (United States)

    Kinnunen, V; Ylä-Outinen, A; Rintala, J

    2015-12-15

    The pulp and paper industry wastewater treatment processes produce large volumes of biosludge. Limited anaerobic degradation of lignocellulose has hindered the utilization of biosludge, but the processing of biosludge using anaerobic digestion has recently regained interest. In this study, biosludge was used as a sole substrate in long-term (400 d) mesophilic laboratory reactor trials. Nine biosludge batches collected evenly over a period of one year from a pulp and paper industry wastewater treatment plant had different solid and nutrient (nitrogen, phosphorus, trace elements) characteristics. Nutrient characteristics may vary by a factor of 2-11, while biomethane potentials (BMPs) ranged from 89 to 102 NL CH4 kg(-1) VS between batches. The BMPs were enhanced by 39-88% with thermal pretreatments at 105-134 °C. Despite varying biosludge properties, stable operation was achieved in reactor trials with a hydraulic retention time (HRT) of 14 d. Hydrolysis was the process limiting step, ceasing gas production when the HRT was shortened to 10 days. However, digestion with an HRT of 10 days was feasible after thermal pretreatment of the biosludge (20 min at 121 °C) due to enhanced hydrolysis. The methane yield was 78 NL CH4 kg(-1) VS for untreated biosludge and was increased by 77% (138 NL CH4 kg(-1) VS) after pretreatment. PMID:26397452

  9. Flotation technique with coagulant and polymer application applied to the post-treatment of effluents from anaerobic reactor treating sewage.

    Science.gov (United States)

    Reali, A P; Penetra, R G; de Carvalho, M E

    2001-01-01

    This paper presents the results of a study performed with a lab-scale batch DAF unit fed with previously coagulated (with FeCl3 and/or cationic polymer) effluent from a pilot-scale expanded bed anaerobic reactor treating domestic sewage. The association between ferric chloride and polymers was studied, aimed at sludge reduction. Ferric chloride dosages ranging from 15 to 65 mg.l-1, and polymer dosages from 0.25 to 7.0 mg.l-1 were investigated. Flocculation conditions were kept constant: 20 min of time (Tf) and 80 s-1 of mean velocity gradient (Gf). Air requirement was kept to 19.0 g of air.m-3 wastewater, using 20% recycle ratio and saturation pressure at 450 kPa. When the anaerobic reactor was operating at steady state conditions, it was possible to reduce the FeCl3 dosage from 65 to 30 mg.l-1 after applying 0.4 mg.l-1 of non-ionic polymer, before the DAF process. For these dosages, 79% COD removal (residual of 23 mg.l-1), 86% total phosphate removal (residual of 0.9 mg.l-1) and 98% turbidity removal (residual of 2.6 NTU) were observed. Furthermore, the use of adequate polymer together with 30 mgFeCl3.l-1 leads to the production of high rising rate flocs. PMID:11575086

  10. 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 bicarbonate concentration were related with the increase of the H2 flow rate. The CH4 content increased from 78.4 % to 90.2 % with the increase of the H2 flow rate from 930 to 1,440 ml/(l  day), while the pH in the reactor remained below 8.0. An even higher CH4 content (96.1 %) was achieved when the H2 flow...... rate was increased to 1,760 ml/(l  day); however, the pH increased to around 8.3 due to bicarbonate consumption which hampered the anaerobic process. The biofilm formed on the HFM was found not to be beneficial for the process since it increased the resistance of H2 diffusion to the liquid. The study...

  11. Enrichment of specific electro-active microorganisms and enhancement of methane production by adding granular activated carbon in anaerobic reactors.

    Science.gov (United States)

    Lee, Jung-Yeol; Lee, Sang-Hoon; Park, Hee-Deung

    2016-04-01

    Direct interspecies electron transfer (DIET) via conductive materials can provide significant benefits to anaerobic methane formation in terms of production amount and rate. Although granular activated carbon (GAC) demonstrated its applicability in facilitating DIET in methanogenesis, DIET in continuous flow anaerobic reactors has not been verified. Here, evidences of DIET via GAC were explored. The reactor supplemented with GAC showed 1.8-fold higher methane production rate than that without GAC (35.7 versus 20.1±7.1mL-CH4/d). Around 34% of methane formation was attributed to the biomass attached to GAC. Pyrosequencing of 16S rRNA gene demonstrated the enrichment of exoelectrogens (e.g. Geobacter) and hydrogenotrophic methanogens (e.g. Methanospirillum and Methanolinea) from the biomass attached to GAC. Furthermore, anodic and cathodic currents generation was observed in an electrochemical cell containing GAC biomass. Taken together, GAC supplementation created an environment for enriching the microorganisms involved in DIET, which increased the methane production rate. PMID:26836607

  12. 新型厌氧反应器UBF的发展及应用%Development and Application of New Anaerobic Reactor UBF

    Institute of Scientific and Technical Information of China (English)

    孙根行; 王丹

    2011-01-01

    The development process of anaerobic biological treatment technology was introduced, and the disadvantages of Up-flow Anaerobic Sludge Blanket were analyzed,the operating principle and application situation of the UBF reactor which was invented based on the UASB reactor were emphasized.%回顾了厌氧生物处理技术的发展历程,分析了UASB反应器的不足之处,重点阐述了在其基础上改进的UBF反应器的工作原理及应用现状.

  13. Simulasi Performansi Heat Exchanger Type Shell And Tube Dengan Double Segmental Baffle Terhadap Helical Baffle

    OpenAIRE

    Anggareza Adhitiya; Djatmiko Ichsani

    2013-01-01

    Pada heat exchanger type shell and tube, selain pengunaan baffle yang bertujuan untuk mengarahkan aliran pada sisi shell juga bertujuan untuk meningkatkan laju perpindahan panas yang terjadi antara fluida kerja dengan cara menimbulkan olakan aliran di sisi shell. Olakan –olakan ini nantinya yang akan mempengaruhi besarnya perpindahan panas dalam sisi shell. Pada kondisi standart baffle yang digunakan pada tugas akhir ini adalah jenis double segmental. Double segmental baffle mempunyai tingkat...

  14. The baffle-barrel-bolting analysis program: evolution and technical accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Schwirian, R.E.; Forsyth, D.R.; Snyder, M.D.; Bhandari, D.R.; Barsic, J.A.; Rabenstein, W.D. [Westinghouse Electric Company, Pittsburgh, Pennsylvania (United States)

    2001-07-01

    In Westinghouse pressurized water reactors (PWR) the reactor core is surrounded by baffle plates, which provide lateral restraint for the fuel assemblies at the core boundary. Baffle plates are attached to horizontal supports called former plates by baffle-former bolts. The formers are attached to the core barrel which also provides vertical support for the core. The B3 analysis program addresses the possibility of reduced baffle-former bolting in Westinghouse U.S. domestic plant designs with respect to the relevant design criteria. Since safety is the overriding motivation for the program, faulted events have received the most in-depth attention. This focus has been reinforced by the fact that the loads produced by the loss-of-coolant-accident (LOCA) have usually been the most limiting of all those considered. Consequently, much of the presentation below deals with the development of analysis techniques and acceptance criteria to demonstrate that LOCA-induced loads on the bolts and the fuel assemblies will be acceptable with significantly reduced baffle-former bolting. A discussion of the other faulted, normal, and upset analyses performed as part of the program will also be presented. (author)

  15. 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...... as co-substrate in the UAF reactor. The AN and the remaining intermediates after the UAF reactor were then efficiently degraded in the ALR reactor. A removal efficiency of 100% and 96% was obtained for NB and chemical oxygen demand (COD), respectively, using sequential UAF/ALR reactors with an HRT of 8......-72 h in the UAF reactor and 2-18 h in the ALR reactor. The corresponding optimal influent NB concentration varied between 100 and 400 mg l super(-1) to achieve the optimal NB and COD removal. The NB removal efficiency decreased to 90% and to 97% if the HRT in the UAF reactor decreased from 8 to 2 h...

  16. Comparison of heat transfer performances of helix baffled heat exchangers with different baffle configurations

    Institute of Scientific and Technical Information of China (English)

    Cong Dong; Yaping Chen; Jiafeng Wu

    2015-01-01

    Numerical simulations were performed on flow and heat transfer performances of heat exchangers having six helical baffles of different baffle shapes and assembly configurations, i.e., two trisection baffle schemes, two quadrant baffle schemes, and two continuous helical baffle schemes. The temperature contour or the pressure contour and velocity contour plots with superimposed velocity vectors on meridian, transverse and unfolded concentric hexagonal slices are presented to obtain a full angular view. For the six helix baffled heat exchangers, the different patterns of the single vortex secondary flow and the shortcut leakage flow were depicted as wel as the heat transfer properties were compared. The results show that the optimum scheme among the six configurations is a circumferential overlap trisection helix baffled heat exchanger with a baffle incline angle of 20° (20°TCO) scheme with an anti-shortcut baffle structure, which exhibits the second highest pressure dropΔpo, the highest overal heat transfer coefficient K, shel-side heat transfer coefficient ho and shel-side average comprehensive index ho/Δpo.

  17. A downflow hanging sponge (DHS) reactor for faecal coliform removal from an upflow anaerobic sludge blanket (UASB) effluent.

    Science.gov (United States)

    Yaya Beas, Rosa Elena; Kujawa-Roeleveld, Katarzyna; van Lier, Jules B; Zeeman, Grietje

    2015-01-01

    This research was conducted to study the faecal coliforms removal capacity of downflow hanging sponge (DHS) reactors as a post-treatment for an upflow anaerobic sludge blanket (UASB) reactor. Three long-term continuous laboratory-scale DHS reactors, i.e. a reactor with cube type sponges without recirculation, a similar one with recirculation and a reactor with curtain type sponges, were studied. The porosities of the applied medium were 91%, 87% and 47% respectively. The organic loading rates were 0.86 kgCOD m(-3) d(-1), 0.53 kgCOD m(-3) d(-1) and 0.24 kgCOD m(-3) d(-1) correspondingly at hydraulic loading rates of 1.92 m3 m(-2) d(-1), 2.97 m3 m(-2) d(-1) and 1.32 m3 m(-2) d(-1), respectively (COD: chemical oxygen demand). The corresponding averages for faecal coliform removal were 99.997%, 99.919% and 92.121% respectively. The 1989 WHO guidelines standards, in terms of faecal coliform content for unrestricted irrigation (category A), was achieved with the effluent of the cube type DHS (G1) without recirculation. Restricted irrigation, category B and C, is assigned to the effluent of the cube type with recirculation and the curtain type, respectively. Particularly for organic compounds, the effluent of evaluated DHS reactors complies with USEPA standards for irrigation of so called non-food crops like pasture for milking animals, fodder, fibre, and seed crops. PMID:26606098

  18. Preliminary evaluation of biosolids characteristics for anaerobic membrane reactors treating municipal wastewaters.

    Science.gov (United States)

    Dong, Qirong; Dagnew, Martha; Cumin, Jeff; Parker, Wayne

    2015-01-01

    This study assessed the characteristics of biosolids of a pilot-scale anaerobic membrane bioreactor (AnMBR) treating municipal wastewater. The production of total solids (TS) and volatile solids (VS) was comparable to that reported for the extended aeration system at solids residence time (SRT) longer than 40 days. The yields of TS and VS were reduced as SRT increased from 40 to 100 days and increased with the addition of 26 mg/L of FeCl3. The AnMBR destroyed 60-82% of the VS loading in feed wastewater and hence it was concluded the biosolids met the requirements for vector attraction reduction for land application. The concentrations of volatile suspended solids and total suspended solids in the sludge were less than those reported after anaerobic digestion of conventional primary and secondary sludge mixtures, and hence dewatering of the waste stream may be required for some applications. The nutrient content in terms of total Kjeldahl nitrogen and total phosphorus was similar to that of anaerobically digested municipal sludges. The dewaterability of the biosolids was poorer than that reported for sludges from aerobic treatment and anaerobically digested sludges. Dewaterability was improved by addition of FeCl3 and reduced SRT. The biosolids met standards for land application with regards to the concentration of heavy metals but would need further treatment to meet Class B pathogen indicator criteria. PMID:26465317

  19. Selective separation of anaerobic sludge by means of hydrocyclones; Selektive Abtrennung von Anaerobschlamm mit Hydrozyklonen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.; Bohnet, M. [Technische Univ. Braunschweig (Germany). Inst. fuer Verfahrens- und Kerntechnik

    1999-07-01

    In anaerobic waste water cleaning, biomass concentration constitutes a central problem because of long generating times and low biomass sinking speeds. In order to decouple hydraulic retention time from biomass retention time, biomass must be fed back into the reactor. The fact that separation by means of common gravitational separators such as sedimentation tanks and baffle plate thickeners is unspecific results in the enrichment in the reactor of inorganic solids, whose presence is corollary to the anaerobic sludge process. Hence, industry has a great interest in separating anaerobic sludge into organic and inorganic constituents as a means of safeguarding high operating stability and degradation efficiency of anaerobic reactors. Hydrocyclones, permitting selective separation, are an obvious approach. (orig.) [German] Bei der anaeroben Abwasserreinigung ist die Biomassekonzentrierung aufgrund langer Generationszeiten und geringer Sinkgeschwindigkeiten der Biomasse ein zentrales Problem. Zur Entkopplung der hydraulischen Verweilzeit von der Verweilzeit der Biomasse ist eine Rueckfuehrung der Biomasse erforderlich. Da bisher eingesetzte Schwerkraftabscheider, wie Absetzbecken und Lamellenklaerer, unspezifisch trennen, kommt es zu einer Anreicherung anorganischer Feststoffe im Reaktor, die sich prozessbedingt im Anaerobschlamm befinden. So hat die Industrie ein grosses Interesse an einer Auftrennung des Anaerobschlamms in organische und anorganische Bestandteile, um eine hohe Betriebsstabilitaet und Abbauleistung der Anaerobreaktoren zu gewaehrleisten. Hierzu bieten sich Hydrozyklone an, weil mit ihnen eine selektive Trennung moeglich ist. (orig.)

  20. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial stage

  1. Simulasi Performansi Heat Exchanger Type Shell And Tube Dengan Double Segmental Baffle Terhadap Helical Baffle

    Directory of Open Access Journals (Sweden)

    Anggareza Adhitiya

    2013-12-01

    Full Text Available Pada heat exchanger type shell and tube, selain pengunaan baffle yang bertujuan untuk mengarahkan aliran pada sisi shell juga bertujuan untuk meningkatkan laju perpindahan panas yang terjadi antara fluida kerja dengan cara menimbulkan olakan aliran di sisi shell. Olakan –olakan ini nantinya yang akan mempengaruhi besarnya perpindahan panas dalam sisi shell. Pada kondisi standart baffle yang digunakan pada tugas akhir ini adalah jenis double segmental. Double segmental baffle mempunyai tingkat pressure drop yang cukup besar. sehingga perlu di ganti dengan baffle jenis helical yang mempunyai pressure drop yang lebih kecil. Untuk mengetahui performansi heat exchanger maka perlu adanya penelitian lebih lanjut simulasi numerik pada baffle heat exchanger type shell and tube. agar didapat pengaruh jenis baffle yang di gunakan terhadap karakteristik aliran dan perpindahan panas dari suatu heat exchanger type shell and tube. Tugas Akhir ini menggunakan program GAMBIT 2.4.6 untuk penggambaran geometri secara tiga dimensi dan program FLUENT 6.3.26 untuk mensimulasi aliran yang terjadi di dalam shell and tube heat exchanger. Pada software FLUENT 6.3.26 digunakan permodelan 3D Steady Flow dengan  memilih k – Epsilon RNG sebagai turbulence modeling serta mengaktifkan persamaan energy. Penelitian dilakukan dengan menggunakan dua variasi heat exchanger dengan jenis baffle yang berbeda .Heat exchanger type shell and tube dengan jenis double segmental baffle mempunyai nilai koefisien konveksi rata-rata = 218.408 w/m2.K. Sedangkan untuk helical baffle sebesar = 171.122 w/m2.K. Temperature outflow pada heat exchanger type shell and tube dengan jenis double segmental baffle = 306.7450K. Di ikuti dengan pressure drop sebesar = 2100 pascal Sedangkan untuk helical baffle mempunyai temperatur outflow sebesar = 307.0220K dengan pressure drop sebesar = 500 pascal.

  2. Reactor performance and microbial community dynamics during anaerobic co-digestion of municipal wastewater sludge with restaurant grease waste at steady state and overloading stages.

    Science.gov (United States)

    Razaviarani, Vahid; Buchanan, Ian D

    2014-11-01

    Linkage between reactor performance and microbial community dynamics was investigated during mesophilic anaerobic co-digestion of restaurant grease waste (GTW) with municipal wastewater sludge (MWS) using 10L completely mixed reactors and a 20day SRT. Test reactors received a mixture of GTW and MWS while control reactors received only MWS. Addition of GTW to the test reactors enhanced the biogas production and methane yield by up to 65% and 120%, respectively. Pyrosequencing revealed that Methanosaeta and Methanomicrobium were the dominant acetoclastic and hydrogenotrophic methanogen genera, respectively, during stable reactor operation. The number of Methanosarcina and Methanomicrobium sequences increased and that of Methanosaeta declined when the proportion of GTW in the feed was increased to cause an overload condition. Under this overload condition, the pH, alkalinity and methane production decreased and VFA concentrations increased dramatically. Candidatus cloacamonas, affiliated within phylum Spirochaetes, were the dominant bacterial genus at all reactor loadings. PMID:25265327

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

    Science.gov (United States)

    Kato, M T; Field, J A; Versteeg, P; Lettinga, G

    1994-08-01

    The application of the expanded granular sludge bed (EGSB) reactor for the anaerobic treatment of low-strength soluble wastewaters using ethanol as a model substrate was investigated in laboratory-scale reactors at 30oC. Chemical oxygen demand (COD) removal efficiency was above 80% at organic loading rates up to12 g COD/L . d with influent concentrations as low as 100 to 200 mg COD/L. These results demonstrate the suitability of the EGBS reactor for the anaerobic treatment of low-strength wastewaters. The high treatment performance can be attributed to the intense mixing regime obtained by high hydraulic and organic loads. Good mixing of the bulk liquid phase for the substrate-biomass contact and adequate expansion of the substrate-biomass contact and adequate expansion of the sludge bed for the degassing were obtained when the liquid upflow velocity (V(up)) was greater than 2.5 m/h. Under such conditions, an extremely low apparent K(s) value for acetoclastic methanogenesis of 9.8 mg COD/L was observed. The presence of dissolved oxygen in the wastewater had no detrimental effect on the treatment performance. Sludge piston flotation from pockets of biogas accumulating under the sludge bed occurred at V(up) lower than 2.5 m/h due to poor bed expansion. This problem is expected only in small diameter laboratory-scale reactors. A. more important restriction of the EGSB reactor was the sludge washout occurring at V(up) higher than 5.5 m/h and which was intensified at organic loads higher than 7 g COD/L. d due to buoyancy forces from the gas production. To achieve an equilibrium between the mixing intensity and the sludge hold-up, the operation should be limited to an organic loading rate of 7 g COD/L d. and to a liquid up-flow velocity between 2.5 and 5.5 m/h (c) 1994 John Wiley & Sons, Inc. PMID:18618781

  4. Numerical investigation on baffle configuration improvement of the heat exchanger with helical baffles

    International Nuclear Information System (INIS)

    Highlights: • Fluid flow and heat transfer was numerically investigated in STHXsHB. • Ladder-type fold baffle was proposed to block triangle leakage zones. • The shell-side tangential velocity and radial velocity increase significantly. • The optimum configuration of ladder-type fold baffle was obtained. • The comprehensive performance of the improved heat exchanger is enhanced. - Abstract: An improved structure of ladder-type fold baffle is proposed to block the triangular leakage zones in original heat exchangers with helical baffles. The numerical results showed that the shell-side tangential velocity and radial velocity in improved heat exchanger increase significantly and the shell-side fluid becomes approximately continuous spiral flow. And the configuration of ladder-type fold baffles was optimized. The numerical results showed that the shell-side heat transfer coefficient of the improved heat exchanger increases by 82.8–86.1%, when the folding ratio φ is 0.3, the baffle height ω is 60%, and the folding angle α is 37°. The associated pumping power penalty is about 21–549 W due to the increased shell-side pressure drop. The thermal performance factor TEF enhances by 28.4–30.7%, which demonstrates that the ladder-type fold baffle effectively improves the heat transfer performance of heat exchangers with helical baffles. The results of this paper are of great significance in the optimal design of heat exchanger

  5. OPTIMIZATION OF HYDRAULIC RETENTION TIME (HRT FOR RAW SUGARMILL WASTEWATER USING ANAEROBIC SEQUENTIAL BATCH REACTOR (AnSBR

    Directory of Open Access Journals (Sweden)

    Dr. S. JAYANTHI

    2013-04-01

    Full Text Available Sugar Industries in India generate about 1000 litres of wastewater for every tonne of sugarcane crushed during the manufacturing process of white crystals i.e. Sugar. There are various biological treatments for treating the wastewater of which here AnSBR is used. Anaerobic Sequential Batch Reactor (AnSBR was operated in mesophillic condition (27°C - 35°C for the treatment of Sugar mill wastewater. The study was initiated by studying the characteristics of the wastewater for the parameters such as pH, Chlorides, Acidity, Alkalinity, Total Solids, Suspended Solids, Total Dissolve Solids, Volatile Solids, Chemical Oxygen Demand (COD and Volatile Fatty Acids. The treatment of the sugar mill wastewater for the production of bio-methane gas is to be carried out in AnSBR at lab scale at room temperature with a volume of 3.5 Litres. The reactors are to be operated in 8 hours cyclic steps for different Hydraulic Retention Time (HRT such as 36, 48 and 72. Four steps involved during the 8 hours operation a Feeding Time (10 mins b Decanting time (10 mins c Reaction time (5.6 hours d Settling time (2 hours. AnSBR was operated in 8hr cyclic steps for 36, 48, 72 hrs HRT. The efficiency of the reactor was determined on basis of the maximum gas production by varying sequence lengths.OLR and HRTs. After 30 days, the AnSBR reactor could able to start with successful granulation. Optimum HRT was found to be 48 hrs at optimum HRT the COD removal % of 92 with a gas yield of 6.7828 L/L.day. The performance of reactor was considerably increased to a tune of 92%.

  6. Performance evaluation of a completely stirred anaerobic reactor treating pig manure at a low range of mesophilic conditions.

    Science.gov (United States)

    Guo, Jianbin; Dong, Renjie; Clemens, Joachim; Wang, Wei

    2013-11-01

    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 4.3g ODML(-1)d(-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 (1.3g ODML(-1)d(-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 0.065g VSSg(-1) CODremoved, which was higher than that at 38°C (0.016g VSSg(-1) CODremoved). PMID:23842452

  7. 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.

  8. Influence of the agitation rate on the treatment of partially soluble wastewater in anaerobic sequencing batch biofilm reactor.

    Science.gov (United States)

    Pinho, Samantha Cristina; Ratusznei, Suzana Maria; Rodrigues, José Alberto Domingues; Foresti, Eugenio; Zaiat, Marcelo

    2004-11-01

    This work reports on the influence of the agitation rate on the organic matter degradation in an anaerobic sequencing batch reactor, containing biomass immobilized on 3 cm cubic polyurethane matrices, stirred mechanically and fed with partially soluble soymilk substrate with mean chemical oxygen demand (COD) of 974+/-70 mg l(-1). Hydrodynamic studies informed on the homogenization time under agitagion rates from 500 to 1100 rpm provided by three propeller impellers. It occurred very quickly compared to the total cycle time. The results showed that agitation provided good mixing and improved the overall organic matter consumption rates. A modified first-order kinetic model represented adequately the data in the entire range of agitation rate. The apparent first-order kinetic constant for suspended COD rose approximately 360% when the agitation rate was changed from 500 to 900 rpm, whereas the apparent first-order kinetic constant for soluble COD did not vary significantly. PMID:15491659

  9. Anaerobic co-digestion of sewage sludge and sugar beet pulp lixiviation in batch reactors: effect of temperature.

    Science.gov (United States)

    Montañés, Rocío; Solera, Rosario; Pérez, Montserrat

    2015-03-01

    The feasibility of anaerobic co-digestion of sewage sludge (SS) and sugar beet pulp lixiviation (SBPL) was assessed. Mesophilic and thermophilic batch assays of five different SS/SBPL ratios were used to investigate the effect of temperature, providing basic data on methane yield and reduction in total volatiles. Microbe concentrations (Eubacteria and methanogenic Archaea) were linked to traditional parameters, namely biogas production and removal of total volatile solids (TVS). The relationship between Eubacteria and Archaea was analysed. Given equal masses of organic matter, net methane generation was higher in the mesophilic range on the biochemical methane potential (BMP) test. Methane yield, TVS removal data and high levels of volatile fatty acids provided further evidence of the best behaviour of the mesophilic range. At the end of testing the microbial population under of the reactors consisted of Eubacteria and Archaea, with Eubacteria predominant in all cases. PMID:25600010

  10. Combined carbon and nitrogen removal in integrated anaerobic/anoxic sludge bed reactors for the treatment of domestic sewage

    OpenAIRE

    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 by means of a sequential anaerobic-aerobic system. The anaerobic pre-treatment can consist of a single anaerobic stage or two anaerobic stages, conditioned mainly by the wastewater characteristics,...

  11. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

    Science.gov (United States)

    Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

    2016-06-01

    The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97–67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach.

  12. 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

  13. The role of acid incubation in rapid immobilization of hydrogen-producing culture in anaerobic upflow column reactors

    International Nuclear Information System (INIS)

    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)

  14. Characterization of the biomass of a hybrid anaerobic reactor (HAR) with two types of support material during the treatment of the coffee wastewater

    OpenAIRE

    Vivian Galdino da Silva; Cláudio Milton Montenegro Campos; Erlon Lopes Pereira; Júlia Ferreira da Silva

    2013-01-01

    This study investigated the microbiology of a hybrid anaerobic reactor (HAR) in the removal of pollutant loads. This reactor had the same physical structure of an UASB reactor, however with minifilters inside containing two types of support material: expanded clay and gravel. Two hydraulic retention times (HRT) of 24h and 18h were evaluated at steady-state conditions, resulting in organic loading rates (OLR) of 0.032 and 0.018 kgDBO5m-3d-1 and biological organic loading rates (BOLR) of 0,0015...

  15. 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. PMID:21398119

  16. A directional spotlight baffle for control cabins

    Science.gov (United States)

    Anderson, K. W.; Clark, B. A. J.

    1980-10-01

    Direct overhead lighting in control cabins frequently gives rise to unwanted bright images of the luminaries in the windows and these images may degrade the cabin operator's view of the external world. A directional baffle incorporating light traps which allow a high ratio of wanted to unwanted illumination from a specific conventional spotlamp is described. In practical tests, images from the spotlamp baffle combination were practically inconspicuous both in day and night conditions. A general method of design is described for extension of the principle to other types of spotlamps.

  17. 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......L-CH4/gVS-added. The treatment of reactor effluent was also investigated. By acidification with sulfuric acid to pH lower than 5, almost 100% of the ammonia content in the effluent could be retained during the successive up-concentration process step. The reactor effluent could be up...

  18. Thermophilic degradation of phenolic compounds in lab scale hybrid up flow anaerobic sludge blanket reactors

    International Nuclear Information System (INIS)

    This Study describes the feasibility of anaerobic degradation of United States Environmental Protection Agency (USEPA) listed 4-chloro-2-nitrophenol (4C-2-NP), 2-chloro-4-nitrophenol (2C-4-NP), 2-chloro-5-methylphenol (2C-5-MP) from a simulated wastewater using four identical 7L bench scale hybrid up flow anaerobic sludge blankets (HUASBs) at five different hydraulic retention times (HRTs) under thermophilic condition (55 ± 3 deg. C). The substrate to co-substrate ratios were maintained between 1:33.3 and 1:166.6. Continuous monitoring of parameters like pH, volatile fatty acids (VFAs) accumulation, oxidation reduction potential, chemical oxygen demand (COD), alkalinity, gas productions, methane percentages were carried out along with compound reduction to asses the efficiency of biodegradation. The compound reduction was estimated by using spectrophotometric methods and further validated with high-performance liquid chromatography (HPLC). Optimum HRT values were observed at 24 h. Optimum ratio of substrate (phenolic compounds) to co-substrate (glucose) was 1:100. Scanning electron micrographs show that the granules were composed of thermophilic Methanobrevibacter and thermophilic Methanothrix like bacteria.

  19. 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. PMID:27055364

  20. PENGARUH PENGGUNAAN BAFFLE PADA SHELL-AND-TUBE HEAT EXCHANGER

    OpenAIRE

    Ekadewi Anggraini Handoyo

    2001-01-01

    Shell-and-tube heat exchanger is a device commonly used to transfer heat. To enhance the heat transfer occurred and to support the tubes inside the shell, baffles are installed. Better heat transfer is obviously expected in a heat exchanger. A research is done to find out the effect of baffle used toward the effectiveness and pressure drop in heat exchanger. The result is that the effectiveness increases when the baffles are installed. Effectiveness increases as the spacing between the baffle...

  1. Anaerobic workout

    OpenAIRE

    McAdam, Ewan J.

    2010-01-01

    Anaerobic technology cannot directly replace current wastewater treatment processes exclusively. The UASB reactor configuration removes slightly less organic carbon by comparison as the process relies on lamella separation for passive clarification rather than using fine pores like anMBR. By contrast, whilst anMBR can operate as a single unit process for organic carbon removal, the membrane surface has to be cleaned using gas sparging to limit surface deposition, which requires extra energy. ...

  2. 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)

  3. Fate of parasites and pathogenic bacteria in an anaerobic hybrid reactor followed by downflow hanging sponge system treating domestic wastewater.

    Science.gov (United States)

    Tawfik, A; El-Zamel, T; Herrawy, A; El-Taweel, G

    2015-08-01

    Treatment of domestic wastewater in a pilot-scale upflow anaerobic hybrid (AH) reactor (0.9 m(3)) in combination with downflow hanging sponge (DHS) system (1.3 m(3)) was investigated. The combined system was operated at a hydraulic retention time (HRT) of 6.0 h for AH and 3.2 h for DHS system. The total process achieved a substantial reduction of COD(total) resulting in an average effluent concentration of only 39 ± 12 mg/l. Moreover, 90 ± 7% of ammonia was eliminated in the DHS system. Nitrate and nitrite data revealed that 49 ± 3.2% of the ammonia removal occurred through nitrification process. The removal efficiency of total coliform (TC), fecal coliform (FC), and fecal streptococci (FS) was relatively low in the AH reactor. The major portion of TC, FC, and FS was removed in the DHS system resulting to an average count of 1.7 × 10(5) ± 1.1 × 10(2)/100 ml for TC, 7.1 × 10(4) ± 1.2 × 10(2)/100 ml for FC, and 7.5 × 10(4) ± 1.3 × 10(2)/100 ml for FS in the final effluent. Likely, the combined system was very efficient for the removal of protozoological species such as sarcodins (Entamoeba cysts), flagellates (Giardia cysts), and ciliates (Balantidium cysts). This was not the case for coccidia (Cryptosporidium oocysts), where 36.4 and 27.3% were detected in the effluent of AH and DHS system, respectively. Only 10% of intestinal nematode and cestode ova were recorded in the effluent of AH reactor and were completely removed in the DHS system. PMID:25893628

  4. 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})

  5. 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.

  6. Dry anaerobic digestion of high solids content dairy manure at high organic loading rates in psychrophilic sequence batch reactor.

    Science.gov (United States)

    Massé, Daniel I; Saady, Noori M Cata

    2015-05-01

    Cow manure with bedding is renewable organic biomass available around the year on dairy farms. Developing efficient and cost-effective psychrophilic dry anaerobic digestion (PDAD) processes could contribute to solving farm-related environmental, energy, and manure management problems in cold-climate regions. This study was to increase the organic loading rate (OLR), fed to a novel psychrophilic (20 °C) dry anaerobic digestion of 27% total solid dairy manure (cow feces and wheat straw) in sequence batch reactor (PDAD-SBR), by 133 to 160%. The PDAD-SBR process operated at treatment cycle length of 21 days and OLR of 7.0 and 8.0 g total chemical oxygen demand (TCOD) kg(-1) inoculum day(-1) (5.2 ± 0.1 and 5.8 ± 0.0 g volatile solids (VS) kg(-1) inoculum day(-1)) for four successive cycles (84 days) produced average specific methane yields (SMYs) of 147.1 ± 17.2 and 143.2 ± 11.7 normalized liters (NL) CH4 kg(-1) VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.45 at OLR of 8.0 g TCOD kg(-1) inoculum day(-1). Hydrolysis was the limiting step reaction. The VS removal averaged around 57.4 ± 0.5 and 60.5 ± 5.7% at OLR 7.0 and 8.0 g TCOD kg(-1) inoculum day(-1), respectively. PMID:25773978

  7. Performance evaluation of the sulfur-redox-reaction-activated up-flow anaerobic sludge blanket and down-flow hanging sponge anaerobic/anoxic sequencing batch reactor system for municipal sewage treatment.

    Science.gov (United States)

    Hatamoto, Masashi; Ohtsuki, Kota; Maharjan, Namita; Ono, Shinya; Dehama, Kazuya; Sakamoto, Kenichi; Takahashi, Masanobu; Yamaguchi, Takashi

    2016-03-01

    A sulfur-redox-reaction-activated up-flow anaerobic sludge blanket (UASB) and down-flow hanging sponge (DHS) system, combined with an anaerobic/anoxic sequencing batch reactor (A2SBR), has been used for municipal sewage treatment for over 2years. The present system achieved a removal rate of 95±14% for BOD, 74±22% for total nitrogen, and 78±25% for total phosphorus, including low water temperature conditions. Sludge conversion rates during the operational period were 0.016 and 0.218g-VSSg-COD-removed(-1) for the UASB, and DHS, respectively, which are similar to a conventional UASB-DHS system, which is not used of sulfur-redox-reaction, for sewage treatment. Using the sulfur-redox reaction made advanced treatment of municipal wastewater with minimal sludge generation possible, even in winter. Furthermore, the occurrence of a unique phenomenon, known as the anaerobic sulfur oxidation reaction, was confirmed in the UASB reactor under the winter season. PMID:26773951

  8. The Status and Development of High-Rate Anaerobic Reactor%高速厌氧反应器的现状与发展

    Institute of Scientific and Technical Information of China (English)

    汪艳霞

    2014-01-01

    对厌氧反应器的研究进展和技术现状进行了全面总结,着重对比UASB反应器、EGSB反应器及微氧EGSB反应器的特点、结构特征及应用现状,结果表明:微氧EGSB反应器具有污泥产量少、出水COD低、高产甲烷活性及强抗冲击负荷能力的优点,是厌氧反应器的发展趋势。%This article systematically summarizes the advance in research and current status of anaerobic reactors, especially comparing the characteristics, structure characteristics and application status of UASB reactor with EGSB reactor and microaerobic EGSB reactor. The results show that, the microaerobic EGSB reactor is the trend of development of anaerobic reactors because of less sludge production, low effluent COD, high methanogenic activity and strong anti-shock loading capacity.

  9. 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...

  10. Anaerobic biodegradability of mixtures of pesticides in an expanded granular sludge bed reactor.

    Science.gov (United States)

    Monsalvo, V M; Garcia-Mancha, N; Puyol, D; Mohedano, A F; Rodriguez, J J

    2014-01-01

    The biodegradability and toxicity of three commercial pesticides containing 2-methyl-4-chlorophenoxyacetic acid (MCPA), imidacloprid and dimethoate were evaluated individually, and a complex mixture of these pesticides was treated in an expanded granular sludge bed (EGSB) reactor. MCPA was partially biodegraded, while imidacloprid and dimethoate remained almost unaltered during the individual biodegradability tests. Cyclohexanone was identified as the major solvent in the dimethoate-bearing insecticide, which was completely removed regardless of the presence of other pesticides. The analysis of the inhibition over the acetoclastic methanogenesis showed IC(50) (half maximal inhibitory concentration) values of 474 and 367 mg/L for imidacloprid and dimethoate, respectively. The effect on the methanogenesis was negligible in the case of MCPA and cyclohexanone. Pesticides caused a dramatic decrease of the EGSB reactor performance. After 30 d acclimation, the EGSB reactor achieved a stable chemical oxygen demand (COD) removal efficiency and methane production of around 85% and 0.9 g CH(4)-COD/g COD, respectively, for MCPA, imidacloprid, dimethoate and cyclohexanone feed concentrations of 57, 20, 25 and 27 mg/L, respectively. The presence of complex pesticide mixtures led to synergistic/antagonistic responses, reducing the MCPA biodegradation and improving the removal of the insecticides' active ingredients, which were completely removed in the EGSB reactor. PMID:24552724

  11. A comparison study on the high-rate co-digestion of sewage sludge and food waste using a temperature-phased anaerobic sequencing batch reactor system.

    Science.gov (United States)

    Kim, Hyun-Woo; Nam, Joo-Youn; Shin, Hang-Sik

    2011-08-01

    Assessing contemporary anaerobic biotechnologies requires proofs on reliable performance in terms of renewable bioenergy recovery such as methane (CH(4)) production rate, CH(4) yield while removing volatile solid (VS) effectively. This study, therefore, aims to evaluate temperature-phased anaerobic sequencing batch reactor (TPASBR) system that is a promising approach for the sustainable treatment of organic fraction of municipal solid wastes (OFMSW). TPASBR system is compared with a conventional system, mesophilic two-stage anaerobic sequencing batch reactor system, which differs in operating temperature of 1st-stage. Results demonstrate that TPASBR system can obtain 44% VS removal from co-substrate of sewage sludge and food waste while producing 1.2m(3)CH(4)/m(3)(system)/d (0.2m(3)CH(4)/kgVS(added)) at organic loading rate of 6.1gVS/L/d through the synergy of sequencing-batch operation, co-digestion, and temperature-phasing. Consequently, the rapid and balanced anaerobic metabolism at thermophilic stage makes TPASBR system to afford high organic loading rate showing superior performance on OFMSW stabilization. PMID:21600764

  12. 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

  13. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

    International Nuclear Information System (INIS)

    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 CH4/g VSadded 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

  14. Biodegradation of phenol with chromium(VI) reduction in an anaerobic fixed-biofilm process-Kinetic model and reactor performance

    International Nuclear Information System (INIS)

    A mathematical model system was derived to describe the simultaneous removal of phenol biodegradation with chromium(VI) reduction in an anaerobic fixed-biofilm reactor. The model system incorporates diffusive mass transport and double Monod kinetics. The model was solved using a combination of the orthogonal collocation method and Gear's method. A laboratory-scale column reactor was employed to validate the kinetic model system. Batch kinetic tests were conducted independently to evaluate the biokinetic parameters used in the model simulation. The removal efficiencies of phenol and chromium(VI) in an anaerobic fixed-biofilm process were approximately 980 mg/g and 910 mg/g, respectively, under a steady-state condition. In the steady state, model-predicted biofilm thickness reached up to 350 μm and suspended cells in the effluent were 85 mg cell/l. The experimental results agree closely with the results of the model simulations.

  15. Buckling behaviour of PFBR main vessel and its thermal baffles under seismic loadings

    International Nuclear Information System (INIS)

    The special feature of pool type fast breeder reactor is the usage of very large sized thin shell structures for its reactor vessels. Due to the large diameter to thickness ratio (around 700 to 900), design of these vessels poses challenging structural mechanics problems particularly under seismic loading. An important threat to structural integrity of reactor vessels is the buckling risk during seismic events. The buckling design involves determination of critical buckling load and comparing it with operating load, to ensure that enough safety factors recommended by RCC-MR are available at all loading levels (RCC-MR 1985). The determination of critical buckling load particularly under seismic loading is a complicated task due to dynamic effects, non-axisymmetric nature of loading, material and geometrical nonlinearities, effect of geometric imperfections and boundary conditions and the interaction of different modes of buckling. Based on literature survey and extensive benchmark studies, the above complexities involved in the buckling analysis have been resolved and subsequent analysis is done for the main vessel and its thermal baffle of Prototype Fast Breeder Reactor (PFBR). The integrity of main vessel is very important since it forms an important part of primary containment and also carries around 1250 t of radioactive sodium. The integrity of thermal baffles is not very important during Safe Shutdown Earthquake (SSE) (level D) loading. However, for the operational basis earthquake (OBE) (Level-B loading), thermal baffles should be designed for meeting buckling criteria since either the loss of their integrity or large displacements may affect the cooling passage for the cold sodium flow and in turn, the temperature of main vessel may rise above the creep temperature. While the straight portion of main vessel is subjected to shear and bending mode of buckling, its dished end is subjected to shell mode buckling during seismic events. The dynamic pressure

  16. 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.

  17. Co-fermentation of oil palm lignocellulosic residue with pig manure in anaerobic leach bed reactor for fatty acid production

    International Nuclear Information System (INIS)

    Highlights: • Pig manure helped stimulate degradation of EFB in the co-fermentation in ALBR. • High manure mixing and long fermentation time favored VFA production. • Derived quadratic model could satisfactorily explain the relationship of parameters. • Species of fatty acids produced were influenced by flooding interval of reactor bed. - Abstract: Batch experiments were performed to investigate the co-fermentation of palm oil empty fruit bunch (EFB) and pig manure (PM) at various PM mixing ratios (%PM) and flushing intervals (FI) over 60-day fermentation time (FT) using anaerobic leach bed reactors. Addition of PM promoted hydrolysis yield (ηh) and acidification yield (ηa) due to the more degradable and soluble nature of PM that gave out organic acids, and nutrients it supplemented. The highest ηh and ηa found were 27.9 ± 0.3% and 51.7 ± 2.6%, respectively. Longer FI that delayed bed flushing prolonged the dry condition where hydrolytic reaction could be enhanced. The developed multiple regression model with R2 = 0.87 and p < 0.0001 suggested a good fit to the data and able to describe the interactive relationship of the parameters on total volatile fatty acids (VFA) production. The longer chain acids, i.e. propionic (C3), butyric (C4), and valeric (C5) acids, were found in higher concentrations with longer FI and higher pig manure mixing ratios. The mixing of an easier biodegradable pig manure as co-substrate could help induce higher degree of fermentation of the recalcitrant EFB

  18. 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. PMID:26853042

  19. Characterization of the biomass of a hybrid anaerobic reactor (HAR with two types of support material during the treatment of the coffee wastewater

    Directory of Open Access Journals (Sweden)

    Vivian Galdino da Silva

    2013-06-01

    Full Text Available This study investigated the microbiology of a hybrid anaerobic reactor (HAR in the removal of pollutant loads. This reactor had the same physical structure of an UASB reactor, however with minifilters inside containing two types of support material: expanded clay and gravel. Two hydraulic retention times (HRT of 24h and 18h were evaluated at steady-state conditions, resulting in organic loading rates (OLR of 0.032 and 0.018 kgDBO5m-3d-1 and biological organic loading rates (BOLR of 0,0015 and 0.001 kgDBO5kgSVT- 1d¹, respectively. The decrease in concentration of organic matter in the influent resulted an endogenous state of the biomass in the reactor. The expanded clay was the best support material for biofilm attachment.

  20. Anaerobic side-stream reactor for excess sludge reduction: 5-year management of a full-scale plant.

    Science.gov (United States)

    Velho, V F; Foladori, P; Andreottola, G; Costa, R H R

    2016-07-15

    The long-term performances of a full-scale anaerobic side-stream reactor (ASSR) aimed at sludge reduction have been monitored for the first time, in comparison with a conventional activated sludge process (CAS). The plant was integrated with an ASSR treatment of 2293-3293 m(3). Operational parameters in the ASSR were: ORP -250 mV, interchange ratio of 7-10%, hydraulic retention time of 7 d. No worsening of effluent quality was observed in the ASSR configuration and removal efficiency of COD and NH4 was above 95%. A slight increase in the Sludge Volume Index did not cause worsening in effluent solids concentration. The observed sludge yield (Yobs) passed from 0.44 kgTSS/kgCOD in the CAS to 0.35 in the ASSR configuration. The reduction of Yobs by 20% is lower than expected from the literature where sythetic wastewater is used, indicating that sludge reduction efficiency is largely affected by inert mass fed with influent real wastewater. An increase by 45% of the ASSR volume did not promote a further reduction of Yobs, because sludge reduction is affected not solely by endogenous decay but also by other factors such as interchange ratio and aerobiosis/anaerobiosis alternation. PMID:27107390

  1. Semi-continuous solid substrate anaerobic reactors for H{sub 2} production from organic waste: Mesophilic versus thermophilic regime

    Energy Technology Data Exchange (ETDEWEB)

    Valdez-Vazquez, Idania; Rios-Leal, Elvira; Esparza-Garcia, Fernando; Poggi-Varaldo, Hector M. [CINVESTAV-IPN, Department Biotechnology and Bioengineering, Environmental Biotechnology, P.O. Box 14-740, Mexico D.F. 07000 (Mexico); Cecchi, Franco [Universita degli Studi di Verona, Verona (Italy)

    2005-11-01

    We evaluated the influence of the operation temperature (mesophilic vs. thermophilic regime) of semicontinuous, acidogenic solid substrate anaerobic digestion (A-SSAD) of the organic fraction of municipal solid waste (OFMSW) at lab scale. The H{sub 2} percentage was higher in the thermophilic regime than in the mesophilic operation (58% and 42%, respectively). The H{sub 2} yield of thermophilic A-SSAD was significantly higher than in our mesophilic reactors (360 vs. 165NmL H{sub 2}/g VS{sub rem}) and other studies reported in the literature (range of 62-180mL/g VS). Mesophilic A-SSAD showed a yield of 37% of the maximum yield based on 4molH{sub 2}/mol hexose, while thermophilic A-SSAD exhibited a yield of 80% of the maximum yield. This result is similar to works with pure cultures of extremophile microorganisms where H{sub 2} yields of 83% of the maximum were reported. We found higher concentrations of acetic acid in the digestates of thermophilic A-SSAD, while butyrate was in higher proportion in mesophilic A-SSAD spent solids. The moderate-to-high yields obtained with the semicontinuous process used in this work are in disagreement with previous reports claiming that batch and semicontinuous processes are less efficient than continuous ones. (author)

  2. Anaerobic mesophilic co-digestion of sugar-beet processing wastewater and beet-pulp in batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Alkaya, Emrah; Demirer, Goeksel N. [Department of Environmental Engineering, Middle East Technical University, Inonu Bulvari, 06531 Ankara (Turkey)

    2011-03-15

    In this study, biochemical methane potential (BMP) assay was conducted to investigate the effect of waste mixing and F/M ratio on the co-digestion of wastewater and beet-pulp, in addition to the digestion of the wastes separately. In the studied F/M range (0.51-2.56 g COD/g VSS), observed treatment efficiencies (63.7-87.3% COD removal and 69.6-89.3% VS reduction) were indications of high biodegradability for both wastewater and beet-pulp, which decreased with increasing F/M. It was evident that the extent of biomethanation of wastewater was higher than beet-pulp, owing to the inherent soluble carbohydrates in wastewater. When the co-digestion of the wastes was evaluated, it came up with the result that, major outcome of wastewater addition was to increase methane production rate of beet-pulp, rather than increasing its ultimate biodegradability. Indeed, modeled first-order rate functions indicated that rate constants (k values) differentiated in the ranges between 0.081 and 0.143 day{sup -1} and 0.028-0.050 day{sup -1} respectively for wastewater added and non-added reactors. These results indicated that anaerobic co-digestion of wastewater and beet-pulp is promising since wastewater addition significantly increases the rate of biomethanation of beet-pulp. (author)

  3. 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. PMID:26824301

  4. 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. PMID:16797956

  5. Assessing the effects of municipal solid waste incinerator bottom ash on the decomposition of biodegradable waste using a completely mixed anaerobic reactor.

    Science.gov (United States)

    Banks, Charles J; Lo, Huang-Mu

    2003-06-01

    Experimental lab scale anaerobic reactors were used to assess the effect of municipal solid waste incinerator (MSWI) bottom ash on the process of biodegradation of organic materials typical of those found in municipal solid waste (MSW). Three reactors were used in the trial and each of these received the same daily organic load of simulated MSW but varying loads of MSWI bottom ash. The reactors were monitored over a period of 200 days for pH, alkalinity, volatile acids, total organic carbon (TOC), biogas production, gas composition and heavy metals. The addition of ash appeared to have beneficial effects on the degradation process as there was an increase in gas production, alkalinity, and pH, coupled with a decrease in the TOC concentration of leachate when compared with a control reactor without MSWI ash addition. After 200 days operation, the alkalinity and gas production in the anaerobic reactor receiving 6g ash per day was twice that of the reactor receiving 3g of ash per day and four times that of the control reactor. A number of tests were carried out on the ash sample to investigate the possible reasons for enhancement of the biodegradative process. These included a shake flask batch leaching test using distilled water, determination of the acid neutralising capacity by titration curve, and the quantification of six heavy metals and four light metals. In the reactors receiving ash the concentrations of Ca, Na, K, Mg ions were found to be significantly higher and these may provide a higher alkalinity which could promote the digestion process. Soluble concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were in the range of 0.02-0.2, 0.01-2.5, 0.01-0.3, 0.01-1, 0.01-1.2, and 0.01-1 mgl(-1) respectively and at these concentrations it is unlikely that they would prove inhibitory to the digestion process. PMID:12870642

  6. 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

  7. One- and two-stage upflow anaerobic sludge-bed reactor pretreatment of winery wastewater at 4-10 degreesC.

    Science.gov (United States)

    Kalyuzhnyi, S V; Gladchenko, M A; Sklyar, V I; Kizimenko, Y S; Shcherbakov, S S

    2001-02-01

    The operating performance of a single and two (in series) laboratory upflow anaerobic sludge-bed (UASB) reactors (2.7-L working volume, recycle ratio varied from 1:1 to 1:18) treating diluted wine vinasse was investigated under psychrophilic conditions (4-10 degreesC). For a single UASB reactor seeded with granular sludge, the average organic loading rates (OLRs) applied were 4.7, 3.7, and 1.7 g of chemical oxygen demand (COD)/(L.d) (hydraulic retention times [HRTs] were about 1 d) at 9-11, 6 to 7, and 4 to 5 degreesC, respectively. The average total COD removal for preacidified vinasse wastewater was about 60% for all the temperature regimes tested. For two UASB reactors in series, the average total COD removal for treatment of non-preacidified wastewater exceeded 70% (the average OLRs for a whole system were 2.2, 1.8, and 1.3 g of COD/[L.d] under HRTs of 2 d at 10, 7, and 4 degreesC, respectively). In situ determinations of kinetic sludge characteristics (apparent Vm and Km) revealed the existence of substantial mass transfer limitations for the soluble substrates inside the reactor sludge bed. Therefore, application of higher recycle ratios is essential for enhancement of UASB pretreatment under psychrophilic conditions. The produced anaerobic effluents were shown to be efficiently posttreated aerobically: final effluent COD concentrations were about 0.1 g/L. Successful operation of the UASB reactors at quite low temperatures (4-10 degreesC) opens some perspectives for application of high-rate anaerobic pretreatment at ambient temperatures. PMID:11297387

  8. 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

  9. Microsatellite Star Tracker Baffles: Validation and Testing

    OpenAIRE

    Marciniak, Martin; Enright, John; Sinclair, Doug; Dzamba, Tom

    2013-01-01

    In this paper, we examine the challenges of ground-based stray light testing from a microsatellite perspective. We consider some of the historical approaches to simulation and laboratory testing and propose strategies for ground validation that require only modest investment in test facilities. The star tracker or instrument is characterized in the lab without any baffle, using a novel technique to subtract out reflections internal to the test chamber. From the resulting data a simulation ele...

  10. 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.

  11. Velocity Profiles between Two Baffles in a Horizontal Circular Tube

    Institute of Scientific and Technical Information of China (English)

    Tae-Hyun Chang; Hae-Soo Lee; Keon-Je Oh; Doeg Hee Doh; Chang-Hoan Lee

    2014-01-01

    The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat.The baffles are also an important element inside the heat exchanger.Internal materials influence the flow pattern in the bed.The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube.The velocity of the particles was measured before the baffle and between them in the test tube.Results show that the flows near the front baffle flow were parallel to the vertical wall,and then concentrate on the upper opening of the front baffle.The flows circulate in the front and rear baffles.These flow profiles are related to the Reynolds number (Re) or the flow intensity.The velocity profiles at lower Re number showed a complicated mixing,concentrating on the lower opening of the rear baffle as front wall.Swirling flow was employed in this study,which was produced using tangential velocities at the inlet.At the entrance of the front baffle,the velocity vector profiles with swirl were much different from that without swirl.However,velocities between two baffles are not much different from those without swirl.

  12. Velocity profiles between two baffles in a horizontal circular tube

    Science.gov (United States)

    Chang, Tae-Hyun; Lee, Hae-Soo; Oh, Keon-Je; Doh, Doeg Hee; Lee, Chang-Hoan

    2014-12-01

    The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat. The baffles are also an important element inside the heat exchanger. Internal materials influence the flow pattern in the bed. The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube. The velocity of the particles was measured before the baffle and between them in the test tube. Results show that the flows near the front baffle flow were parallel to the vertical wall, and then concentrate on the upper opening of the front baffle. The flows circulate in the front and rear baffles. These flow profiles are related to the Reynolds number (Re) or the flow intensity. The velocity profiles at lower Re number showed a complicated mixing, concentrating on the lower opening of the rear baffle as front wall. Swirling flow was employed in this study, which was produced using tangential velocities at the inlet. At the entrance of the front baffle, the velocity vector profiles with swirl were much different from that without swirl. However, velocities between two baffles are not much different from those without swirl.

  13. BaffleText: a Human Interactive Proof

    Science.gov (United States)

    Chew, Monica; Baird, Henry S.

    2003-01-01

    Internet services designed for human use are being abused by programs. We present a defense against such attacks in the form of a CAPTCHA (Completely Automatic Public Turing test to tell Computers and Humans Apart) that exploits the difference in ability between humans and machines in reading images of text. CAPTCHAs are a special case of 'human interactive proofs,' a broad class of security protocols that allow people to identify themselves over networks as members of given groups. We point out vulnerabilities of reading-based CAPTCHAs to dictionary and computer-vision attacks. We also draw on the literature on the psychophysics of human reading, which suggests fresh defenses available to CAPTCHAs. Motivated by these considerations, we propose BaffleText, a CAPTCHA which uses non-English pronounceable words to defend against dictionary attacks, and Gestalt-motivated image-masking degradations to defend against image restoration attacks. Experiments on human subjects confirm the human legibility and user acceptance of BaffleText images. We have found an image-complexity measure that correlates well with user acceptance and assists in engineering the generation of challenges to fit the ability gap. Recent computer-vision attacks, run independently by Mori and Jitendra, suggest that BaffleText is stronger than two existing CAPTCHAs.

  14. Identical full-scale biogas-lift reactors (Blrs) with anaerobic granular sludge and residual activated sludge for brewery wastewater treatment and kinetic modeling.

    Science.gov (United States)

    Xu, Fu; Huang, Zhenxing; Miao, Hengfeng; Ren, Hongyan; Zhao, Mingxing; Ruan, Wenquan

    2013-10-01

    Two identical full-scale biogas-lift reactors treating brewery wastewater were inoculated with different types of sludge to compare their operational conditions, sludge characteristics, and kinetic models at a mesophilic temperature. One reactor (R1) started up with anaerobic granular sludge in 12 weeks and obtained a continuously average organic loading rate (OLR) of 7.4 kg chemical oxygen demand (COD)/(m3 x day), COD removal efficiency of 80%, and effluent COD of 450 mg/L. The other reactor (R2) started up with residual activated sludge in 30 weeks and granulation accomplished when the reactor reached an average OLR of 8.3 kg COD/(m3 x day), COD removal efficiency of 90%, and effluent COD of 240 mg/L. Differences in sludge characteristics, biogas compositions, and biogas-lift processes may be accounted for the superior efficiency of the treatment performance of R2 over R1. Grau second-order and modified StoverKincannon models based on influent and effluent concentrations as well as hydraulic retention time were successfully used to develop kinetic parameters of the experimental data with high correlation coefficients (R2 > 0.95), which further showed that R2 had higher treatment performance than R1. These results demonstrated that residual activated sludge could be used effectively instead of anaerobic granular sludge despite the need for a longer time. PMID:24494489

  15. Enhancement of the performance of an anaerobic sequencing batch reactor treating low-strength wastewater through implementation of a variable stirring rate program

    Directory of Open Access Journals (Sweden)

    Rodrigues J. A. D.

    2004-01-01

    Full Text Available 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 30ºC 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.

  16. Effective anaerobic biodegradation of municipal solid waste fresh leachate using a novel pilot-scale reactor: comparison under different seeding granular sludge.

    Science.gov (United States)

    Luo, Jinghuan; Zhou, Jizhi; Qian, Guangren; Liu, Jianyong

    2014-08-01

    A novel integrated internal and external circulation (IIEC) reactor was developed for anaerobic biodegradation of municipal solid waste (MSW) fresh leachate with chemical oxygen demand (COD) between 40,000 and 60,000mg/l. The pilot-scale IIEC reactor was inoculated with two kinds of granular sludge from paper mill (SPM) and from citric acid factory (SCF), respectively. The bio-treating capacity in contaminant removal and biogas production performed much superior to others' results, principally attributed to appropriate configuration modification. Compared to SCF, much higher organic loading rate (40.5 vs 23.0kgCOD/m(3)d) and COD removal efficiency (>80% vs 60-75%) were achieved for the reactor with SPM. For methane production, 11.77 or ∼6m(3)STP/m(3)d of rate and 66-85% of content were observed with SPM or SCF, respectively. Due to better sludge concentrations and methanogenic activity, these findings indicate the anaerobic reactor could effectively bio-treat MSW leachate for methane generation, especially inoculated with granular sludge derived from leachate-like-wastewater. PMID:24755395

  17. 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

    2016-01-01

    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. PMID:27112502

  18. 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.

  19. 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

    2016-01-01

    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. PMID:27112502

  20. Anaerobes beyond anaerobic digestion

    OpenAIRE

    Sousa, D. Z.; Pereira, M A; Alves, M.M.

    2009-01-01

    Anaerobic microorganisms are widespread in nature. Sediments, gastrointestinal tracks, volcanic vents, geothermal sources are examples of habitats where anaerobic metabolism prevail, in some cases at extreme temperature, pH and pressure conditions. In such microbial ecosystems waste of some is food for others in a true integrated structure. Anaerobic microorganisms are able to use a wide variety of organic and inorganic compounds. Recalcitrant compounds, such as hydrocarbons, a...

  1. 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

  2. Kinetics of para-nitrophenol and chemical oxygen demand removal from synthetic wastewater in an anaerobic migrating blanket reactor

    International Nuclear Information System (INIS)

    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-1p-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 (KB) and maximum utilization rate constants (Rmax) were found as 31.55 g COD L-1 day-1, 29.49 g COD L-1 day-1 for COD removal and 0.428 g p-NP L-1 day-1, 0.407 g p-NP L-1 day-1 for p-NP removal, respectively (R2 = 1). The values of (a) and (b) were found to be 0.096 day and 1.071 (dimensionless) with high correlation coefficients of R2 = 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, Gmax, and proportionality constant, GB, 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 (KID = 14 and 23 mg L-1) for p-NP concentrations higher than 40 mg L-1 while the half velocity constant (Ks) increased from 10 to 60 and 118 mg L-1 with increasing p-NP concentrations from 40 to 85 and 125 mg L-1

  3. A start-up of psychrophilic anaerobic sequence batch reactor digesting a 35 % total solids feed of dairy manure and wheat straw

    OpenAIRE

    Saady, Noori M. Cata; Massé, Daniel I.

    2015-01-01

    Zero liquid discharge is currently an objective in livestock manure management to minimize water pollution. This paper reports the start-up phase of a novel psychrophilic (20 °C) dry anaerobic digestion of dairy manure with bedding fed at 35 % total solids and an organic loading rate of 3.0 g total chemical oxygen demand kg−1 inoculum day−1 in anaerobic sequence batch reactors. The specific methane (CH4) yield ranged from 165.4 ± 9.8 to 213.9 ± 13.6 NL CH4 kg−1 volatile solids (VS) with an ov...

  4. Numerical Study on Improved Baffle in Compact Test Separator

    OpenAIRE

    Yanhai Wei; Xinran Wang; Limin He; Shenghua Jiao; Guoqiang Zhang; Hao Cheng; Yujiang Li; Tao Li

    2014-01-01

    The aim of this paper is to design two improved baffles to solve the injection problem caused by traditional baffle in compact test separator and use FLUENT software to study their effects on separator pressure loss and separation efficiency. The result shows: that anti-injection baffle can make compact test separator with a high separation efficiency with a relatively low pressure loss. Also, the diameter of anti-injection plate which makes the compact test separator at its highest separatio...

  5. Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor for thermophilic palm oil mill effluent (POME) treatment

    International Nuclear Information System (INIS)

    Upflow anaerobic sludge blanket-hollow centered packed bed (UASB-HCPB) reactor was developed with the aim to minimize operational problems in the anaerobic treatment of Palm Oil Mill Effluent (POME) under thermophilic conditions. The performance of UASB-HCPB reactor on POME treatment was investigated at 55 °C. Subsequent to start-up, the performance of the UASB-HCPB reactor was evaluated in terms of i) effect of hydraulic retention time (HRT); ii) effect of organic loading rate (OLR); and iii) effect of mixed liquor volatile suspended solid (MLVSS) concentration on thermophilic POME treatment. Start-up up of the UASB-HCPB reactor was completed in 36 days, removing 88% COD and 90% BOD respectively at an OLR of 28.12 g L−1 d−1, producing biogas with 52% of methane. Results from the performance study of the UASB-HCPB reactor on thermophilic POME treatment indicated that HRT of 2 days, OLR of 27.65 g L−1 d−1 and MLVSS concentration of 14.7 g L−1 was required to remove 90% of COD and BOD, 80% of suspended solid and at the same time produce 60% of methane. - Highlights: • UASB-HCPB was proposed for POME treatment under thermophilic conditions. • Start-up up of the UASB-HCPB reactor was completed in 36 days. • 88% COD and 90% BOD were removed at an OLR of 28.12 g COD/L.day during start-up. • HRT of 2 days and OLR of 27.65 g COD/L.day was required to produce 60% methane. • Methanosarcina sp. forms the majority of microbial population in the UASB section

  6. PENGARUH PENGGUNAAN BAFFLE PADA SHELL-AND-TUBE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Ekadewi Anggraini Handoyo

    2001-01-01

    Full Text Available Shell-and-tube heat exchanger is a device commonly used to transfer heat. To enhance the heat transfer occurred and to support the tubes inside the shell, baffles are installed. Better heat transfer is obviously expected in a heat exchanger. A research is done to find out the effect of baffle used toward the effectiveness and pressure drop in heat exchanger. The result is that the effectiveness increases when the baffles are installed. Effectiveness increases as the spacing between the baffles is smaller until certain spacing, and then it decreases. Abstract in Bahasa Indonesia : Shell-and-tube heat exchanger merupakan jenis alat penukar panas yang banyak digunakan. Untuk membuat perpindahan panas lebih baik dan untuk menyangga tube yang ada di dalam shell, maka sering dipasang baffle. Perpindahan panas yang lebih baik sangat diharapkan dalam suatu heat exchanger. Penelitian dilakukan untuk mengetahui pengaruh penggunaan baffle terhadap efektifitas dan penurunan tekanan dalam heat exchanger. Dari hasil penelitian didapat bahwa efektifitas meningkat dengan dipasangnya baffle. Efektifitas meningkat seiring dengan mengecilnya jarak antar baffle hingga suatu jarak tertentu, kemudian menurun. Kata kunci: penukar kalor, baffle, efektifitas.

  7. Anaerobic digestion of horse dung mixed with different bedding materials in an upflow solid-state (UASS) reactor at mesophilic conditions.

    Science.gov (United States)

    Böske, Janina; Wirth, Benjamin; Garlipp, Felix; Mumme, Jan; Van den Weghe, Herman

    2014-04-01

    Aim of this study was to investigate the use of upflow anaerobic solid-state (UASS) digestion for treating horse manure. Biochemical methane potential (BMP) tests conducted for varying mixtures of dung (hay and silage feed) and bedding material (wheat straw, flax, hemp, wood chips) showed that straw mixed with hay horse dung has the highest potential of [Formula: see text] . Continuous mesophilic digestion was conducted for 238 days using a single-stage UASS reactor (27 L) and a two-stage UASS system with an anaerobic filter (AF, 21 L). Increasing the organic loading rate (OLR) from 2.5 to 4.5 g vs L(-1)d(-1) enhanced the methane rate of the single-stage reactor from 0.262 to 0.391 LL(-1)d(-1) while the methane yield declined from 104.8 to 86.9 L kg vs(-1). The two-stage system showed similar yields. Thus, for solid-state digestion of horse manure a single-stage UASS reactor appears sufficient. PMID:24583222

  8. Effect of pentachlorophenol and chemical oxygen demand mass concentrations in influent on operational behaviors of upflow anaerobic sludge blanket (UASB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shen Dongsheng [Department of Environmental engineering, Zhejiang University, 268 Kaixuan Road, HangZhou 310029 (China)]. E-mail: shends@zju.edu.cn; He Ruo [Department of Environmental engineering, Zhejiang University, 268 Kaixuan Road, HangZhou 310029 (China); Liu Xinwen [Department of Environmental engineering, Zhejiang University, 268 Kaixuan Road, HangZhou 310029 (China); Department of Chemical engineering, Ningbo University of Technology, 20 Cuibai Road, NingBo 315016 (China); Long Yan [Department of Environmental engineering, Zhejiang University, 268 Kaixuan Road, HangZhou 310029 (China)

    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{sup -1} PCP and 1250-10000 mg L{sup -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{sup -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{sup -1} in influent, respectively, [COD] in influent had to be controlled about 1250-7500, 2500-5000 and 5000 mg L{sup -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{sup -1}, respectively. With the increase of [PCP] in influent

  9. Effect of pentachlorophenol and chemical oxygen demand mass concentrations in influent on operational behaviors of upflow anaerobic sludge blanket (UASB) reactor

    International Nuclear Information System (INIS)

    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 of [COD] in

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Habeeb, S.A.; Latiff, AB. Aziz Abdul; Daud, Zawawi; Ahmad, Zulkifli [Faculty of Civil and Enviromental Engineering, University Tun Hussein Onn (Malaysia)

    2011-07-01

    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.

  12. Effect of the influent COD concentration on the anaerobic digestion of winery wastewaters from grape-red and tropical fruit (guava) wine production in fluidized bed reactors with chilean natural zeolite for biomass immobilization

    OpenAIRE

    Montalvo, Silvio; Guerrero, Lorna; Borja Padilla, Rafael; Cortés, Isel; Sánchez, Enrique; Colmenarejo Morcillo, Manuel F.

    2010-01-01

    The effect of the influent COD concentration on the performance of anaerobic fluidized bed reactors treating winery wastewaters from grape-red wine (GRWW) and guava wine production (GWW) was studied at laboratory scale. Two reactors were used: one treating GRWW (AFB1) and the other processing GWW (AFB2). The behaviour of these reactors packed with Chilean zeolite as biomass immobilization support was compared at mesophilic temperature (35 °C). Influent COD varied from 1–24 g L...

  13. 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

  14. Microbial Communities and Their Performances in Anaerobic Hybrid Sludge Bed-Fixed Film Reactor for Treatment of Palm Oil Mill Effluent under Various Organic Pollutant Concentrations

    OpenAIRE

    Kanlayanee Meesap; Nimaradee Boonapatcharoen; Somkiet Techkarnjanaruk; Pawinee Chaiprasert

    2012-01-01

    The anaerobic hybrid reactor consisting of sludge and packed zones was operated with organic pollutant loading rates from 6.2 to 8.2 g COD/L day, composed mainly of suspended solids (SS) and oil and grease (O&G) concentrations between 5.2 to 10.2 and 0.9 to 1.9 g/L, respectively. The overall process performance in terms of chemical oxygen demands (COD), SS, and O&G removals was 73, 63, and 56%, respectively. When the organic pollutant concentrations were increased, the resultant methane poten...

  15. Using a Statistical Model to Examine the Effect of COD: SO42− Ratio, HRT and LA Concentration on Sulfate Reduction in an Anaerobic Sequencing Batch Reactor

    OpenAIRE

    Rajesh Singh; Chungman Moon; Sathyanarayan S. Veeravalli; Saravanan R. Shanmugam; Subba Rao Chaganti; Jerald A. Lalman

    2014-01-01

    Taguchi statistical design, an orthogonal array (OA) method, was used to study the impact of the COD/SO42− ratio, hydraulic retention time (HRT) and linoleic acid (LA) concentration on sulfate (SO42−) reduction in an anaerobic sequencing batch reactor using glucose as the electron donor. Based on the OA, optimum condition for maximum SO42− reduction was evaluated. Increasing the COD/SO42− ratio and HRT caused decreasing SO42− reduction while increased SO42− reduction was observed with increas...

  16. 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

    to sugar mixtures of glucose and xylose ranging from 12 to 41 g/l. The organism, thermophilic anaerobic bacterium Thermoanaerobacter BG1L1, exhibited significant resistance to high levels of acetic acid (up to 10 g/l) 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...

  17. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    OpenAIRE

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated bymeasuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor opera...

  18. On-site evaluation of the performance of a full-scale down-flow hanging sponge reactor as a post-treatment process of an up-flow anaerobic sludge blanket reactor for treating sewage in India.

    Science.gov (United States)

    Okubo, Tsutomu; Onodera, Takashi; Uemura, Shigeki; Yamaguchi, Takashi; Ohashi, Akiyoshi; Harada, Hideki

    2015-10-01

    A down-flow hanging sponge (DHS) reactor is a novel, unaerated, aerobic, biofilm reactor that is used to polish effluent received from an up-flow anaerobic sludge blanket (UASB) reactor for treating municipal sewage. A full-scale DHS reactor was constructed for post-treatment of a full-scale UASB reactor at a municipal sewage treatment plant in India. Performance of the DHS reactor was evaluated with respect to organic removal over 1800 days of continuous operation. The UASB+DHS system consistently produced effluent with chemical oxygen demand (COD), biochemical oxygen demand (BOD), and suspended solids (SS) values of 37, 6.0 and 19 mg L(-1), on average, respectively. The sludge yield of the DHS reactor was estimated to be 0.04 kg SS kg(-1) COD removed or 0.12 kg SS kg(-1) BOD removed, which is considerably lower than other aerobic treatment methods that have been employed for polishing UASB effluent. PMID:26188558

  19. Kinetic modeling and microbial assessment by fluorescent in situ hybridization in anaerobic sequencing batch biofilm reactors treating sulfate-rich wastewater

    Directory of Open Access Journals (Sweden)

    A. J. Silva

    2011-06-01

    Full Text Available This paper reports the results of applying anaerobic sequencing batch biofilm reactors (AnSBBR for treating sulfate-rich wastewater. The reactor was filled with polyurethane foam matrices or with eucalyptus charcoal, used as the support for biomass attachment. Synthetic wastewater was prepared with two ratios between chemical oxygen demand (COD and sulfate concentration (COD/SO4(2- of 0.4 and 3.2. For a COD/SO4(2- ratio of 3.2, the AnSBBR performance was influenced by the support material used; the average levels of organic matter removal were 67% and 81% in the reactors filled with polyurethane foam and charcoal, respectively, and both support materials were associated with similar levels of sulfate reduction (above 90%. In both reactors, sulfate-reducing bacteria (SRB represented more than 65% of the bacterial community. The kinetic model indicated equilibrium between complete- and incomplete-oxidizing SRB in the reactor filled with polyurethane foam and predominantly incomplete-oxidizing SRB in the reactor filled with charcoal. Methanogenic activity seems to have been the determining factor to explain the better performance of the reactor filled with charcoal to remove organic matter at a COD/SO4(2- ratio of 3.2. For a COD/SO4(2- ratio of 0.4, low values of sulfate reduction (around 32% and low reaction rates were observed as a result of the small SRB population (about 20% of the bacterial community. Although the support material did not affect overall performance for this condition, different degradation pathways were observed; incomplete oxidation of organic matter by SRB was the main kinetic pathway and methanogenesis was negligible in both reactors.

  20. A start-up of psychrophilic anaerobic sequence batch reactor digesting a 35 % total solids feed of dairy manure and wheat straw.

    Science.gov (United States)

    Saady, Noori M Cata; Massé, Daniel I

    2015-12-01

    Zero liquid discharge is currently an objective in livestock manure management to minimize water pollution. This paper reports the start-up phase of a novel psychrophilic (20 °C) dry anaerobic digestion of dairy manure with bedding fed at 35 % total solids and an organic loading rate of 3.0 g total chemical oxygen demand kg(-1) inoculum day(-1) in anaerobic sequence batch reactors. The specific methane (CH4) yield ranged from 165.4 ± 9.8 to 213.9 ± 13.6 NL CH4 kg(-1) volatile solids (VS) with an overall average of 188 ± 17 NL CH4 kg(-1) VS during 11 successive start-up cycles (231 days) and a maximum CH4 production rate of 10.2 ± 0.6 NL CH4 kg(-1) VS day(-1). The inoculum-to-substrate (VS-based) ratio ranged from 4.06 to 4.47. Although methanogenesis proceeded fairly well the hydrolysis seemed to be the rate limiting step. It is possible start up psychrophilic dry anaerobic digestion of cow feces and wheat straw at feed TS of 35 % within 7-10 successive cycles (147-210 days). PMID:26289773

  1. Rotary disc reactor for aerobic, anoxic, and anaerobic wastewater treatment. Possible applications and mathematical modelling; Rotationsscheibenreaktor fuer die aerobe, anoxische und anaerobe Abwasserreinigung. Praktische Einsatzmoeglichkeiten und mathematische Modellierung

    Energy Technology Data Exchange (ETDEWEB)

    Breithaupt, T.

    1997-10-01

    This report presents the results of studies on a rotary disk reactor. The reactor`s load limit was determined for all the various biological wastewater treatment methods. Two advantages of the reactor became apparent, namely that it can take high biomass concentrations and is very occlusion-safe when charged with solids-bearing wastewaters. The author also gives a mathematical description of the formation of stationary axial concentration profiles using methane formation from acetic acid as model substrate. Flow conditions inside the reactor are described by means of a model based on retention time measurements. In spite of the numerous simplifications made in the fluidic model and biomass distribution, in calculating ionic strength, neglecting diffusion in the biofilm, and in interpolating the pH profiles most of the measured profiles can be mapped mathematically with a fair degree of accuracy. The author exemplifies how neglection of ionic strength or simplification of flow conditions influences mapping quality. (orig.). 80 figs., 30 tabs. [Deutsch] Die vorliegende Arbeit stellt die Ergebnisse der Untersuchungen an den mit einem neuartigen Textilstrukturbelag ausgestatteten Rotationsscheibenreaktoren dar. Es wurden die Belastungsgrenzen fuer alle Verfahren der biologischen Abwasserreinigung ermittelt. Dabei zeigen sich die Vorteile des Reaktors, der neben der hohen Biomassekonzentration ein hohes Mass an Verstopfungssicherheit bei feststoffhaltigen Abwaessern bietet. - Ausserdem wird die Ausbildung stationaerer, axialer Konzentrationsprofile anhand der anaeroben Methanbildung aus Essigsaeure als Modellsubstrat mathematisch beschrieben. Fuer die Stroemungsverhaeltnisse innerhalb des Reaktors wird ein auf Verweilzeitverteilungsmessungen beruhendes Modell erstellt. Trotz der zahlreichen Vereinfachungen, die im stroemungstechnischen Modell, in der Biomasseverteilung, in der Vernachlaessigung der Diffusion im Biofilm, in der Interpolation of pH-Wert-Profile und in der

  2. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    Science.gov (United States)

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  3. 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. PMID:25176306

  4. Quantifying Contribution of Synthrophic Acetate Oxidation to Methane Production in Thermophilic Anaerobic Reactors by Membrane Inlet Mass Spectrometry

    DEFF Research Database (Denmark)

    Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S.;

    2014-01-01

    silage, and deep litter was incubated with 100 mM of [2-13C] sodium acetate under thermophilic anaerobic conditions. MIMS was used to measure the isotopic distribution of dissolved CO2 and CH4 during the degradation of acetate, while excluding interference from water by applying a cold trap. After 6 days...... a new approach for online quantification of the relative contribution of methanogenesis pathways to methane production with a time resolution shorter than one minute. The observed contribution of SAO-HM to methane production under the tested conditions challenges the current widely accepted anaerobic...

  5. An improved enzyme-linked immunosorbent assay for whole-cell determination of methanogens in samples from anaerobic reactors

    DEFF Research Database (Denmark)

    Sørensen, A.H.; Ahring, B.K.

    1997-01-01

    An enzyme-linked immunosorbent assay was developed for the detection of whole cells of methanogens in samples from anaerobic continuously stirred tank digesters treating slurries of solid waste. The assay was found to allow for quantitative analysis of the most important groups of methanogens...... in samples from anaerobic digesters in a reproducible manner. Polyclonal antisera against eight strains of methanogens were employed in the test, The specificities of the antisera were increased by adsorption with cross-reacting cells. The reproducibility of the assay depended on the use of high...

  6. Heat transfer in tube bundles of heat exchangers with flow baffles induced forced mixing

    International Nuclear Information System (INIS)

    Thermal analysis of shell-and-tube heat exchangers is being investigated through geometric modeling of the unit configuration in addition to considering the heat transfer processes taking place within the tube bundle. The governing equations that characterize the heat transfer from the shell side fluid to the tube side fluid across the heat transfer tubewalls are indicated. The equations account for the heat transfer due to molecular conduction, turbulent thermal diffusion, and forced fluid mixing among various shell side fluid channels. The analysis, though general in principle, is being applied to the Clinch River Breeder Reactor Plant-Intermediate Heat Exchanger, which utilizes flow baffles appropriately designed for induced forced fluid mixing in the tube bundle. The results of the analysis are presented in terms of the fluid and tube wall temperature distributions of a non-baffled and baffled tube bundle geometry. The former case yields axial flow in the main bundle region while the latter is associated with axial/cross flow in the bundle. The radial components of the axial/cross flow yield the necessary fluid mixing that results in reducing the thermal unbalance among the heat transfer to the allowable limits. The effect of flow maldistribution, present on the tube or shell sides of the heat exchangers, in altering the temperature field of tube bundles is also noted

  7. Batch Tests To Determine Activity Distribution and Kinetic Parameters for Acetate Utilization in Expanded-Bed Anaerobic Reactors

    OpenAIRE

    Fox, Peter; Suidan, Makram T.

    1990-01-01

    Batch tests to measure maximum acetate utilization rates were used to determine the distribution of acetate utilizers in expanded-bed sand and expanded-bed granular activated carbon (GAC) reactors. The reactors were fed a mixture of acetate and 3-ethylphenol, and they contained the same predominant aceticlastic methanogen, Methanothrix sp. Batch tests were performed both on the entire reactor contents and with media removed from the reactors. Results indicated that activity was evenly distrib...

  8. 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.). PMID:22797243

  9. 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

  10. Improving anaerobic digestion of pig manure by adding in the same reactor a stabilizing agent formulated with low-grade magnesium oxide

    International Nuclear Information System (INIS)

    Struvite precipitation and pig manure anaerobic digestion were coupled in the same reactor in order to mitigate the inhibitory effect of free ammonia and avoid precipitator costs. The stabilizing agent used to facilitate struvite precipitation was formulated with low-grade magnesium oxide by-product; an approach that would notably reduce struvite processing costs. The interaction between pig manure and stabilizing agent was analyzed in batch experiments, on a wide range of stabilizing agent additions from 5 to 100 kg m−3. The monitoring of the pH and ammonia removal during 24 h showed the high capacity of the stabilizing agent to remove ammonia; removal efficiencies above 80% were obtained from 40 kg m−3. However, a long-term anaerobic digester operation was required to assess the feasibility of the process and to ensure that the stabilizing agent does not introduce any harmful compound for the anaerobic biomass. In this vein, the addition of 5 and 30 kg m−3 of the stabilizing agent in a pig manure continuous digester resulted in a 25% (0.17 m3 kg−1) and a 40% (0.19 m3 kg−1) increase in methane production per mass of volatile solid, respectively, when compared with the reference digester (0.13 m3 kg−1). Moreover, the stability of the process during four hydraulic retention times guarantees that the stabilizing agent did not exert a negative effect on the consortium of microorganisms. Finally, scanning electron microscopy and X-ray diffraction analysis confirmed the presence of struvite as well as two precipitation mechanisms, struvite precipitation on the stabilizing agent surface and in the bulk solution. - Highlights: • Anaerobic digestion and struvite precipitation were satisfactorily coupled. • The stabilizing agent showed high ammonia removals efficiencies. • The stabilizing agent improved the methane production of a pig manure digester. • The stabilizing agent does not introduce harmful compound for the anaerobic biomass.

  11. Development of biofilm in anaerobic reactors treating wastewater from coffee grain processing Desenvolvimento de biofilme em reatores anaeróbios tratando água residuária do processamento dos frutos do cafeeiro

    OpenAIRE

    Fátima R. L. Fia; Alisson C. Borges; Antonio T. de Matos; Iolanda C. S. Duarte; Ronaldo Fia; Lidiane C. de Campos

    2010-01-01

    In recent decades the use of anaerobic fixed bed reactors has been established in Brazil for the treatment of different effluents. As the capability of retaining microorganisms by support media (fixed bed) is a factor influencing the performance of these reactors, the present study aims at evaluating the influence of three fixed bed on the effectiveness of treating an effluent with high pollution potential: wastewater from coffee grain processing (WCP), with organic matter concentrations vary...

  12. Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Keith J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sokolov, Mikhail A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-30

    In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniques to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x1021 n/cm2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of

  13. Assessment of Interaction between Baffles and Impeller Blades in Stirred Tanks

    Directory of Open Access Journals (Sweden)

    Gradov Dmitry

    2016-01-01

    Full Text Available In this work, the sensitivity of hydrodynamics on stirrer position is considered when the Multiple Reference Frame technique is applied to simulate mixing tanks of single and multiphase systems. A typical stirred reactor equipped with four baffles and a six blade Rushton turbine was chosen for the studies. Operational conditions of constant speed (5 rps and 2.653·10−4 m/s gas superficial velocity with single bubble size (1 mm were set. The reactor was simulated in Fluent 15 with four different impeller blade positions. The results were averaged and validated against experimental data produced by Particle Image Velocimetry. The comparison was made using profiles of velocity components along the sampled lines representing various zones of the vessel. The impeller angle of rotation with respect to baffle position was found to contribute to the overall reactor hydrodynamics especially for multiphase systems. Averaging of the simulation results was found to improve the accuracy of the simulated mixing hydrodynamics.

  14. A combined upflow anaerobic sludge bed, aerobic, and anoxic fixed-bed reactor system for removing tetramethylammonium hydroxide and nitrogen from light-emitting diode wastewater.

    Science.gov (United States)

    Lin, Han-Lin; Chen, Sheng-Kun; Huang, Yu-Wen; Chen, Wei-Cheng; Chien, Wei-Cheng; Cheng, Sheng-Shung

    2016-06-01

    A laboratory study using a combined upflow anaerobic sludge bed (UASB) and aerobic and anoxic fixed-bed reactor system was undertaken to explore its capability for removing tetramethylammonium hydroxide (TMAH) and nitrogen from light-emitting diode wastewater. When the organic loading rate was maintained at 0.26-0.65 kg TMAH m(-3 )d(-1), the UASB reactor removed 70-100% of TMAH through methanogenesis. When the [Formula: see text] -N loading rate was maintained at 0.73-1.4 kg [Formula: see text]-N m(-3 )d(-1), the aerobic reactor oxidized 31-59% of [Formula: see text]-N to [Formula: see text]-N through nitritation. When the nitrogen loading rate was maintained at 0.42-0.75 kg N m(-3 )d(-1), the anoxic reactor removed 27-63% of nitrogen through anammox. The performance data of the combined reactor system agreed well with the stoichiometric relationships of methanogenesis, nitritation, and anammox. The batch studies showed that a higher initial TMAH concentration of up to 2520 mg L(-1) gave a higher methanogenic activity of up to 16 mL CH4 g(-1) VSS d(-1). An increase in the initial TMAH concentration of up to 500 mg L(-1) gradually decreased the activity of ammonia-oxidizing bacteria; whereas an increase in the initial TMAH concentration of up to 47 mg L(-1) imposed a marked inhibiting effect on the activity of anammox bacteria. PMID:26583577

  15. 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.

  16. Effects of feeding strategies on the performance of an anaerobic discontinuous reactor containing immobilized biomass with circulation system for liquid-phase mixing.

    Science.gov (United States)

    Orra, A A; Ratusznei, S M; Rodrigues, J A D; Foresti, E; Zaiat, M

    2004-01-01

    Data on the influence of feeding strategy on the performance of a fed-batch anaerobic sequencing reactor containing biomass immobilized on polyurethane foam and subjected to liquid phase circulation are presented and discussed. Six-hour cycles, temperature of 30 degrees C and circulation flow rate of 6 L/h were used. During each cycle 890 mL of synthetic domestic wastewater, with organic matter concentration of 500 mgCOD/L were fed to the reactor. The feeding strategies were implemented using fill times of 6 min (batch mode), 60, 120, 240 (fed-batch/batch mode) and 360 min (fed-batch mode). The system attained high efficiency and stability for all the operating conditions, and the substrate removal efficiency based on filtered samples presented a slight decrease from 85% to 81% when fill time was increased from 6 min to 360 min. A model considering a first-order kinetic equation was fitted to the experimental data. The apparent kinetic parameters for both batch and fed-batch phases were estimated, thus permitting evaluation of the influence of the feeding strategy on the reactor performance. The current system may be considered flexible in terms of the operating conditions it is subjected to. PMID:15303755

  17. 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)

    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 celluloytic and fermentative bacteria were present in the hydrogen producing ASBR. PMID:24672398

  18. The eROSITA x-ray baffle

    Science.gov (United States)

    Friedrich, Peter; Rohé, C.; Gaida, R.; Hartwig, J.; Soller, F.; Bräuninger, H.; Budau, B.; Burkert, W.; Burwitz, V.; Eder, J.; Hartner, G.; Menz, B.; Predehl, P.

    2014-07-01

    The X-ray baffle is an important part of the eROSITA mirror assembly as it reduces the stray light caused by single reflections at the Wolter 1 Mirrors by more than 90%. The stray light problem and possible solutions were analyzed by ray-tracing resulting in a trade-off between effective stray light protection and avoidance of vignetting. Possible design alternatives were considered and the influences of manufacturing tolerances were studied. Other than for XMM, the eROSITA X-ray baffle could not be realized as sieve plates; instead a system of co-aligned "baffle rings" was mounted onto each of the mirror modules. The mechanical design is based on concentric Invar foils fixed by an own spider. The complete X-ray baffles were finally mounted to the mirror module while the alignment was controlled by optical means.

  19. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.

    2006-01-01

    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent vis

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

    OpenAIRE

    Maria Octoviane Dyan; Gita Permana Putra; Budiyono Budiyono; Siswo Sumardiono; Tutuk Djoko Kusworo

    2015-01-01

    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 p...

  1. 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.

  2. 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%.

  3. 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. PMID:26188597

  4. A thermally baffled device for highly stabilized convective PCR

    OpenAIRE

    Chang, Hsiao-Fen Grace; Tsai, Yun-Long; Tsai, Chuan-Fu; Lin, Ching-Ko; Lee, Pei-Yu; Teng, Ping-Hua; Su, Chen; Jeng, Chien-Chung

    2012-01-01

    Rayleigh-Bénard convective PCR is a simple and effective design for amplification of DNA. Convective PCR is, however, extremely sensitive to environmental temperature fluctuations, especially when using small- diameter test tubes. Therefore, this method is inherently unstable with limited applications. Here, we present a convective PCR device that has been modified by adding thermal baffles. With this thermally baffled device the influence from fluctuations in environmental temperature were s...

  5. 厌氧反应器的发展及ABSBR的工艺特点%Development of Anaerobic Reactor and Technological Features of ABSBR

    Institute of Scientific and Technical Information of China (English)

    朱易春; 冯秀娟; 张光明

    2011-01-01

    新型高效厌氧反应器的发展使生活污水的厌氧处理成为可能.介绍了ABSBR(恒水位操作厌氧生物膜序批式反应器,Anaerobic Biofilm Sequencing Batch Reactor)的工艺特点,并对其处理生活污水进行了初步研究.试验结果表明,ABSBR工艺是活性污泥法与生物膜法的结合,具有强的生物固体截留能力和良好的水力混合条件.系统能提高有机物和悬浮固体的去除,此外还具备较强的抗冲击负荷和抗低温能力.

  6. Potential enhancement of direct interspecies electron transfer for syntrophic metabolism of propionate and butyrate with biochar in up-flow anaerobic sludge blanket reactors.

    Science.gov (United States)

    Zhao, Zhiqiang; Zhang, Yaobin; Holmes, Dawn E; Dang, Yan; Woodard, Trevor L; Nevin, Kelly P; Lovley, Derek R

    2016-06-01

    Promoting direct interspecies electron transfer (DIET) to enhance syntrophic metabolism may be a strategy for accelerating the conversion of organic wastes to methane, but microorganisms capable of metabolizing propionate and butyrate via DIET under methanogenic conditions have yet to be identified. In an attempt to establish methanogenic communities metabolizing propionate or butyrate with DIET, enrichments were initiated with up-flow anaerobic sludge blanket (UASB), similar to those that were previously reported to support communities that metabolized ethanol with DIET that relied on direct biological electrical connections. In the absence of any amendments, microbial communities enriched were dominated by microorganisms closely related to pure cultures that are known to metabolize propionate or butyrate to acetate with production of H2. When biochar was added to the reactors there was a substantial enrichment on the biochar surface of 16S rRNA gene sequences closely related to Geobacter and Methanosaeta species known to participate in DIET. PMID:26967338

  7. Influence of baffle configurations on flow and heat transfer characteristics of trisection helical baffle heat exchangers

    International Nuclear Information System (INIS)

    Highlights: • Nephograms with velocity-vector superimposed are proposed on special slices. • Single vortex secondary flow and shortcut leakage patterns are clearly depicted. • Local heat transfer coefficient field and average value on tubes are presented. • Circumferential overlap scheme performs best over other schemes. - Abstract: Numerical simulation of flow and heat transfer characteristics in four trisection helical baffle heat exchangers with equilateral triangle tube layouts was conducted. The heat exchangers have the same helical pitch but four different baffle shapes or connections, i.e., a circumferential overlap (CO) scheme, an end-to-end (EE) scheme, a blocked V-notches (BV) scheme, and a middle axial overlap (MO) scheme. The single vortex secondary flow in each helical cycle and the leakage flow patterns in the V-notches of the adjacent baffles of these schemes are clearly depicted on the meridian slices and unfolded hexagon slices. The results for nine tubes in a 60° sector and four tube layers reveal that the local heat transfer coefficient of the center tube is much higher than that of the other tubes for all the schemes. The results show that the CO scheme has the highest shell-side heat transfer coefficient and comprehensive indexes, the BV scheme has the highest pressure drop and the worst comprehensive indexes, and the MO scheme has the lowest values of both shell-side heat transfer coefficient and pressure drop and the second highest comprehensive indexes. The average values of comprehensive index ho/Δpo of CO scheme in the calculated range is respectively 16.5%, 27.3% and 13.5% higher than that of the EE, BV and MO schemes

  8. 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.

  9. 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

    Science.gov (United States)

    Desta, Adey Feleke; Assefa, Fassil; Leta, Seyoum; Stomeo, Francesca; Wamalwa, Mark; Njahira, Moses; Appolinaire, Djikeng

    2014-01-01

    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 SO42- and S2-, 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. PMID:25541981

  10. 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; Ahring, Birgitte Kiær

    1998-01-01

    % (mole/mole) of the effluent chloroethenes. No dechlorination of PCE was observed in an abiotic control consisting of sterile granules without inoculum, During continuous operation with stepwise-reduced hydraulic retention times (HRTs), both the test reactor and the R1 reactor showed conversion of PCE to...

  11. 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...... regarding the treatment of xenobiotics is shown with the focus on the UASB reactor, but the applicability of other reactor designs for treatment of hazardous waste is also included. Bioaugmentation has proved to be a viable technique to enhance a specific activity in anaerobic reactors and recent research...... on reactor and in situ bioaugmentation is reported....

  12. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

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

    2001-01-01

    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......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...

  13. 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. PMID:16939090

  14. Enhancing mixing of particles by baffles in a rotating drum mixer

    Institute of Scientific and Technical Information of China (English)

    Maoqiang Jiang; Yongzhi Zhao; Gesi Liu; Jinyang Zheng

    2011-01-01

    Baffles with shape of “-” (single baffle), “+” (cross-baffles with four arms) and (baffles with 6 arms)are used to enhance the mixing of particles in a rotating drum mixer. A micro-dynamics study of mixing and segregation of a bi-disperse system of two particle sizes in the rotating drum with these three kinds of baffles is carried out using the discrete element method (DEM). The effect of the baffles on mixing, and the mechanisms of mixing enhancement by the baffles are discussed and analyzed. Simulation results show that in an unbaffled drum mixer, particle convection, particle diffusion, and size segregation of bidisperse particles, all play important roles in the mixing process; whereas size segregation will be largely restrained when the drum mixer has a baffle, regardless of its shape, and the degree of mixing is higher than that in an unbaffled drum mixer. The different mixing characteristics for “-” shaped baffle, “+” baffle,and baffle are revealed by the simulation results. For “+” or “*” style baffles, there is an optimal size of baffles for the mixing of particles, and the optimal mixing efficiency is higher than that for “-” baffle.

  15. Impact on reactor configuration on the performance of anaerobic MBRs: treatment of settled sewage in temperate climates.

    Science.gov (United States)

    Martin Garcia, I; Mokosch, M; Soares, A; Pidou, M; Jefferson, B

    2013-09-15

    The treatment efficiency and membrane performance of a granular and suspended growth anaerobic membrane bioreactor (G-AnMBR and AnMBR respectively) were compared and evaluated. Both anaerobic MBRs were operated in parallel during 250 days with low strength wastewater and under UK weather conditions. Both systems presented COD and BOD removal efficiencies of 80-95% and >90% respectively. Effluent BOD remained between 5 and 15 mgBOD L(-1) through the experimental period while effluent COD increased from 25 mg L(-1) to 75 mg L(-1) as temperature decreased from 25 °C to 10 °C respectively indicating the production of non biodegradable organics at lower temperatures. Although similar levels of low molecular weight organics were present in the sludge supernatant, recycling of the mixed liquor from the membrane tank to the bioreactor at a low upflow velocity enhanced interception of solids in the sludge bed of the G-AnMBR limiting the solid and colloidal load to the membrane as compared to the suspended system. Results from flux step test showed that critical flux increased from 4 to 13 L m(-2) h(-1) and from 3 to 5 L m(-2) h(-1) with gas sparging intensities varying from 0.007 m s(-1) to 0.041. Additional long term trials in which the effect of gas sparging rate and backwashing efficiency were assessed confirmed the lower fouling propensity of the G-AnMBR. PMID:23863382

  16. Nitrogen removal from wastewater by anaerobic methane-driven denitrification in a lab-scale reactor: heterotrophic denitrifiers associated with denitrifying methanotrophs.

    Science.gov (United States)

    He, Zhanfei; Wang, Jiaqi; Zhang, Xu; Cai, Chaoyang; Geng, Sha; Zheng, Ping; Xu, Xinhua; Hu, Baolan

    2015-12-01

    Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered bioprocess that reduces nitrite to dinitrogen with methane as electron donor, which has promising potential to remove nitrogen from wastewater. In this work, a lab-scale sequencing batch reactor (SBR) was operated for 609 days with methane as the sole external electron donor. In the SBR, nitrite in synthetic wastewater was removed continuously; the final volumetric nitrogen removal rate was 12.22±0.02 mg N L(-1) day(-1) and the percentage of nitrogen removal was 98.5 ± 0.2 %. Microbial community analysis indicated that denitrifying methanotrophs dominated (60-70 %) the population of the final sludge. Notably, activity testing and microbial analysis both suggested that heterotrophic denitrifiers existed in the reactor throughout the operation period. After 609 days, the activity testing indicated the nitrogen removal percentage of heterotrophic denitrification was 17 ± 2 % and that of n-damo was 83 ± 2 %. A possible mutualism may be developed between the dominated denitrifying methanotrophs and the associated heterotrophs through cross-feed. Heterotrophs may live on the microbial products excreted by denitrifying methanotrophs and provide growth factors that are required by denitrifying methanotrophs. PMID:26342737

  17. 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)

  18. Modeling the performance of 'up-flow anaerobic sludge blanket' reactor based wastewater treatment plant using linear and nonlinear approaches-A case study

    International Nuclear Information System (INIS)

    The paper describes linear and nonlinear modeling of the wastewater data for the performance evaluation of an up-flow anaerobic sludge blanket (UASB) reactor based wastewater treatment plant (WWTP). Partial least squares regression (PLSR), multivariate polynomial regression (MPR) and artificial neural networks (ANNs) modeling methods were applied to predict the levels of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in the UASB reactor effluents using four input variables measured weekly in the influent wastewater during the peak (morning and evening) and non-peak (noon) hours over a period of 48 weeks. The performance of the models was assessed through the root mean squared error (RMSE), relative error of prediction in percentage (REP), the bias, the standard error of prediction (SEP), the coefficient of determination (R2), the Nash-Sutcliffe coefficient of efficiency (Ef), and the accuracy factor (Af), computed from the measured and model predicted values of the dependent variables (BOD, COD) in the WWTP effluents. Goodness of the model fit to the data was also evaluated through the relationship between the residuals and the model predicted values of BOD and COD. Although, the model predicted values of BOD and COD by all the three modeling approaches (PLSR, MPR, ANN) were in good agreement with their respective measured values in the WWTP effluents, the nonlinear models (MPR, ANNs) performed relatively better than the linear ones. These models can be used as a tool for the performance evaluation of the WWTPs.

  19. Modeling phosphorus removal and recovery from anaerobic digester supernatant through struvite crystallization in a fluidized bed reactor.

    Science.gov (United States)

    Rahaman, Md Saifur; Mavinic, Donald S; Meikleham, Alexandra; Ellis, Naoko

    2014-03-15

    The cost associated with the disposal of phosphate-rich sludge, the stringent regulations to limit phosphate discharge into aquatic environments, and resource shortages resulting from limited phosphorus rock reserves, have diverted attention to phosphorus recovery in the form of struvite (MAP: MgNH4PO4·6H2O) crystals, which can essentially be used as a slow release fertilizer. Fluidized-bed crystallization is one of the most efficient unit processes used in struvite crystallization from wastewater. In this study, a comprehensive mathematical model, incorporating solution thermodynamics, struvite precipitation kinetics and reactor hydrodynamics, was developed to illustrate phosphorus depletion through struvite crystal growth in a continuous, fluidized-bed crystallizer. A thermodynamic equilibrium model for struvite precipitation was linked to the fluidized-bed reactor model. While the equilibrium model provided information on supersaturation generation, the reactor model captured the dynamic behavior of the crystal growth processes, as well as the effect of the reactor hydrodynamics on the overall process performance. The model was then used for performance evaluation of the reactor, in terms of removal efficiencies of struvite constituent species (Mg, NH4 and PO4), and the average product crystal sizes. The model also determined the variation of species concentration of struvite within the crystal bed height. The species concentrations at two extreme ends (inlet and outlet) were used to evaluate the reactor performance. The model predictions provided a reasonably good fit with the experimental results for PO4-P, NH4-N and Mg removals. Predicated average crystal sizes also matched fairly well with the experimental observations. Therefore, this model can be used as a tool for performance evaluation and process optimization of struvite crystallization in a fluidized-bed reactor. PMID:24384559

  20. Performance evaluation of up-flow anaerobic sludge blanket (UASB) reactor for treatment of paper mill wastewater

    Institute of Scientific and Technical Information of China (English)

    M. Mahadevaswamy; B.M. Sadashiva Murthy; A.R. Girijamma

    2004-01-01

    The present study deals with the performance evaluation of the UASB reactor under varied organic loadingrate(OLR) for the treatment of paper mill wastewater. The sludge granulation process started after 120 days from thed) the VSS concentration was 12.86 gVSS/L, which got increased to 38.05 gVSS/L at the end of an OLR 2.1process. Many times the pH observed was between 6.5 and 7.8, which is more favorable for any anaerobicprocess. It is also found that pH within the reactor increases along with the height of reactor. The total maximumremoval at this stage was observed to be 90%.

  1. 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). PMID:18619146

  2. Using a Statistical Model to Examine the Effect of COD: SO42− Ratio, HRT and LA Concentration on Sulfate Reduction in an Anaerobic Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Rajesh Singh

    2014-11-01

    Full Text Available Taguchi statistical design, an orthogonal array (OA method, was used to study the impact of the COD/SO42− ratio, hydraulic retention time (HRT and linoleic acid (LA concentration on sulfate (SO42− reduction in an anaerobic sequencing batch reactor using glucose as the electron donor. Based on the OA, optimum condition for maximum SO42− reduction was evaluated. Increasing the COD/SO42− ratio and HRT caused decreasing SO42− reduction while increased SO42− reduction was observed with increasing LA concentration (1 g L−1. In control (not fed LA cultures, higher SO42− reduction (87% ± 3% was observed at a low COD/SO42− ratio of 0.8. This indicates that increasing SO42− reduction was observed at increasing SO42− loading rates. In general, results from this study reveal that limiting the substrate concentration with high SO42− levels (low COD/SO42− ratio favors high SO42− removal. Surface plots were used to evaluate the significant interactions between the experimental factors. Accuracy of the model was verified using an analysis of residuals. Optimum conditions for maximum SO42− reduction (97.61% were observed at a COD/SO42− ratio of 0.8 (level 1, 12 h HRT (level 1 together with 1000 mg L−1 LA addition (level 3. In general, the Taguchi OA provided a useful approach for predicting the percent SO42− reduction in inhibited mixed anaerobic cultures within the factor levels investigated.

  3. Telescope baffle performance for Lyman Far Ultraviolet Spectrographic Explorer

    Science.gov (United States)

    Morbey, Christopher; Hutchings, J. B.

    1993-07-01

    The Lyman Far Ultraviolet Spectrographic Explorer telescope is a Wolter type II glancing incidence design with an aperture of 64 cm. Because the spacecraft is required to guide on stars fainter than m(v) = 16, a visible light baffle is necessary to protect the FOV from the stray light that results from out-of-field bright sources. Such a baffle system is described here. Total point-source transmittances are computed for incident beams in the range 0-70 deg. Estimates for background brightness on the detector are made for the contribution from direct sunlight and earthshine. Scattering from the black surfaces of the baffle, the vanes, and diffraction at the structure's edges are taken into consideration.

  4. The effect of acidic pH and presence of metals as parameters in establishing a sulfidogenic process in anaerobic reactor.

    Science.gov (United States)

    Vieira, Bárbara F; Couto, Pâmela T; Sancinetti, Giselle P; Klein, Bernhard; van Zyl, Dirk; Rodriguez, Renata P

    2016-08-23

    The successful use of anaerobic reactors for bioremediation of acid mine drainage has been shown in systems with neutral pH. However, the choice of an efficient and suitable process for such wastewater must consider the capability of operating at acidic pH and in the presence of metals. This work studies the performance of an anaerobic batch reactor, under conditions of varying initial pH for its efficiencies in sulfate removal and metal precipitation from synthetic acid mine drainage. The chemical oxygen demand/sulfate (COD/SO4(2-)) ratio used was 1.00, with ethanol chosen as the only energy and carbon source. The initial pH of the synthetic drainage was progressively set from 7.0 to 4.0 to make it as close as possible to that of real acid mine drainage. Metals were also added starting with iron, zinc, and finally copper. The effectiveness of sulfate and COD removal from the synthetic acid mine drainage increased as the initial pH was reduced. The sulfate removal increased from 38.5 ± 3.7% to 52.2 ± 3%, while the removal of organic matter started at 91.7 ± 2.4% and ended at 99 ± 1%. These results indicate that the sulfate reducing bacteria (SRB) community adapted to lower pH values. The metal removal observed was 88 ± 7% for iron, 98.0 ± 0.5% for zinc and 99 ± 1% for copper. At this stage, an increase in the sulfate removal was observed, which reaches up to 82.2 ± 5.8%. The kinetic parameters for sulfate removal were 0.22 ± 0.04 h(-1) with Fe, 0.26 ± 0.04 h(-1) with Fe and Zn and 0.44 ± 0.04 h(-1) with Fe, Zn, and Cu. PMID:27222283

  5. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the...... design of an acidogenic continuously stirred reactor tank in a RAS single-sludge denitrification set-up. The biochemical methane potential of the sludge was estimated to 318 ± 29 g CH4 g-1 TVS0 by a batch assay and represented a higher utility of the solid waste when comparing the methane yield with the...... biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated by measuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor operation at hydrolysis time (HT) / hydraulic retention time (HRT) of 1, 5, or 10 days (and for batch...

  6. The baffle aperture region of an ion thruster

    International Nuclear Information System (INIS)

    During the period of this research project, electron bombardment ion thrusters have passed from an advanced state of development to highly successful flight demonstrations (e.g. Deep Space 1). Such advances made by NASA have been quickly followed in the commercial sector (e.g. NSSK of communications satellites). In the next few years, these early successes will be followed by many new electric propulsion missions, planned by the world's space agencies and commercial space organisations. These early successes will spawn more ambitious and demanding missions, necessitating thrusters of different power demands, thrusts and sizes. Scaling of the UK series of electron bombardment ion thrusters has previously been carried out by semi- empirical scaling laws. These scaling laws have worked well within a certain range of thruster sizes with some iterative redesign necessary to produce acceptable efficiencies. However, when scaling beyond the ranges of the T5, T6 and UK25, the current scaling laws cannot be used due to the conflicting requirements of magnetic field strength in the discharge chamber and baffle aperture region. The baffle aperture region contains a plasma double layer that accelerates primary electrons into the discharge chamber and thus controls ionisation in the ion thruster. Previously, the baffle aperture region was poorly understood. An extensive and unique experimental investigation of the plasma properties around this critical baffle aperture region has been carried out using Langmuir probes. The externally applied magnetic field has been mapped and the Langmuir probe results have been validated using emissive probes. Results are presented on both argon and xenon propellant and high- resolution maps of an extensive range of plasma properties are plotted over a continuous area from the coupling plasma, through the baffle aperture and into the discharge plasma. Maps were taken over a unique and wide range of thruster operating conditions in which all

  7. Seismic Analysis of a Liquid Storage Tank with a Baffle

    Science.gov (United States)

    Gedikli, A.; Ergüven, M. E.

    1999-05-01

    The effects of a rigid baffle on the seismic response of liquid in a rigid cylindrical tank are presented. A baffle is an additional structural element which supplies a kind of passive control on the effects of earthquake motion. Fluid motion is assumed to be irrotational, incompressible and inviscid. The method of superposition of modes has been implemented to compute the seismic response. The boundary element method is used to evaluate the natural modes of liquid in a cylindrical tank. Linearized free surface conditions have been taken into consideration.

  8. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    OpenAIRE

    Zhang Bin; Xue Bin; Qiu Zhigang; Chen Zhiqiang; Li Junwen; Gong Taishi; Zou Wenci; Wang Jingfeng

    2015-01-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all ...

  9. REMOVAL OF ORGANIC MATTER AND TOXICITY IN AN UPFLOW IMMOBILIZED BIOMASS ANAEROBIC REACTOR TREATING HOSPITAL WASTEWATER: PRELIMINARY EVALUATION

    Directory of Open Access Journals (Sweden)

    MÓNICA PORRAS TORRES

    2013-01-01

    Full Text Available El objetivo de esta investigación consistió en evaluar el desempeño de un reactor anaerobio de flujo ascendente de biomasa inmovilizada (RAFABI tratando un efluente hospitalario real. Se estudió la remoción de materia orgánica y toxicidad, por medio de análisis como UV254, DQOfiltrada y determinación del porcentaje de inhibición en el crecimiento de la raíz de la cebolla. Los resultados mostraron que el proceso biológico estuvo estable durante los 287 días de operación continua, el valor medio de la relación AI/AP fue de 1.21±0.08, indicando que no hubo acumulación de ácidos en el sistema. Sin embargo, los valores de la eficiencia de remoción de DQOfiltrada, 56±15% y UV254, 21±36%, no fueron representativos. La toxicidad se redujo en 50%. Con base en lo anterior, es necesario utilizar el reactor anaerobio en combinación con otros procesos como por ejemplo los procesos de oxidación avanzada, para continuar reduciendo la materia orgánica recalcitrante al proceso anaerobio. Se comprobó la capacidad que tienen los reactores anaerobios de biomasa inmovilizada para remover la toxicidad.

  10. 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.

  11. Biotransformation of a highly chlorinated PCB mixture in an activated sludge collected from a Membrane Biological Reactor (MBR) subjected to anaerobic digestion

    International Nuclear Information System (INIS)

    The role of anaerobic digestion (AD) on the decontamination and biomethanization of a PCB-spiked sludge obtained from a Membrane Biological Reactor (MBR) pilot plant was investigated throughout a 10-month batch experiment. The study was carried out under mesophilic (35 deg. C) and thermophilic (55 deg. C) conditions and was monitored by means of an integrated chemical, microbiological and molecular biology strategy. Remarkable PCB depletions (higher than 50% of the overall spiked PCBs) and dechlorinations were achieved under methanogenic conditions. The process was not affected by yeast extract addition. Both acetoclastic and hydrogenotrophic methanogens, together with some fermentative eubacteria, were found to persist in all PCB biodegrading microcosms. This finding, together with those obtained from parallel microcosms where specific populations were selectively inhibited, suggested that native methanogens played a key role in the biodegradation and dechlorination of the spiked PCBs. Taken together, the results of this study indicate that AD is a feasible option for the decontamination and the efficient disposal (with the production of a CH4-rich biogas) of contaminated MBR sludge, which can be then employed as a fertilizer for agricultural purposes.

  12. Effect of influent COD/SO4(2-) ratios on biodegradation behaviors of starch wastewater in an upflow anaerobic sludge blanket (UASB) reactor.

    Science.gov (United States)

    Lu, Xueqin; Zhen, Guangyin; Ni, Jialing; Hojo, Toshimasa; Kubota, Kengo; Li, Yu-You

    2016-08-01

    A lab-scale upflow anaerobic sludge blanket (UASB) has been run for 250days to investigate the influence of influent COD/SO4(2-) ratios on the biodegradation behavior of starch wastewater and process performance. Stepwise decreasing COD/SO4(2-) ratio enhanced sulfidogenesis, complicating starch degradation routes and improving process stability. The reactor exhibited satisfactory performance at a wide COD/SO4(2-) range ⩾2, attaining stable biogas production of 1.15-1.17LL(-1)d(-1) with efficient simultaneous removal of total COD (73.5-80.3%) and sulfate (82.6±6.4%). Adding sulfate favored sulfidogenesis process and diversified microbial community, invoking hydrolysis-acidification of starch and propionate degradation and subsequent acetoclastic methanogenesis; whereas excessively enhanced sulfidogenesis (COD/SO4(2-) ratios methane conversion. This research in-depth elucidated the role of sulfidogenesis in bioenergy recovery and sulfate removal, advancing the applications of UASB technology in water industry from basic science. PMID:27132225

  13. Eliminating methanogenic activity in hydrogen reactor to improve biogas production in a two-stage anaerobic digestion process co-digesting municipal food waste and sewage sludge.

    Science.gov (United States)

    Zhu, Heguang; Parker, Wayne; Conidi, Daniela; Basnar, Robert; Seto, Peter

    2011-07-01

    Laboratory scale two-stage anaerobic digestion process model was operated for 280 days to investigate the feasibility to produce both hydrogen and methane from a mixture feedstock (1:1 (v/v)) of municipal food waste and sewage sludge. The maximum hydrogen and methane yields obtained in the two stages were 0.93 and 9.5 mL/mL feedstock. To eliminate methanogenic activity and obtain substantial hydrogen production in the hydrogen reactor, both feedstock and mixed liquor required treatment. The heat treatment (100°C, 10 min) for feedstock and a periodical treatment (every 2-5 weeks, either heating, removal of biomass particles or flushing with air) for mixed liquor were effective in different extent. The methane production in the second stage was significantly improved by the hydrogen production in the first stage. The maximum methane production obtained in the period of high hydrogen production was more than 2-fold of that observed in the low hydrogen production period. PMID:21592783

  14. 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. PMID:27372008

  15. Thermotoga lettingae sp. nov., a novel thermophilic, methanol-degrading bacterium isolated from a thermophilic anaerobic reactor.

    Science.gov (United States)

    Balk, Melike; Weijma, Jan; Stams, Alfons J M

    2002-07-01

    A novel, anaerobic, non-spore-forming, mobile, Gram-negative, thermophilic bacterium, strain TMOT, was isolated from a thermophilic sulfate-reducing bioreactor operated at 65 C with methanol as the sole substrate. The G+C content of the DNA of strain TMOT was 39.2 mol%. The optimum pH, NaCl concentration, and temperature for growth were 7.0, 1.0%, and 65 degrees C, respectively. Strain TMOT was able to degrade methanol to CO2 and H2 in syntrophic culture with Methanothermobacter thermautotrophicus AH or Thermodesulfovibrio yellowstonii. Thiosulfate, elemental sulfur, Fe(III) and anthraquinone-2,6-disulfonate were able to serve as electron acceptors during methanol degradation. In the presence of thiosulfate or elemental sulfur, methanol was converted to CO2 and partly to alanine. In pure culture, strain TMOT was also able to ferment methanol to acetate, CO2 and H2. However, this degradation occurred slower than in syntrophic cultures or in the presence of electron acceptors. Yeast extract was required for growth. Besides growing on methanol, strain TMOT grew by fermentation on a variety of carbohydrates including monomeric and oligomeric sugars, starch and xylan. Acetate, alanine, CO2, H2, and traces of ethanol, lactate and alpha-aminobutyrate were produced during glucose fermentation. Comparison of 16S rDNA genes revealed that strain TMOT is related to Thermotoga subterranea (98%) and Thermotoga elfii (98%). The type strain is TMOT (= DSM 14385T = ATCC BAA-301T). On the basis of the fact that these organisms differ physiologically from strain TMOT, it is proposed that strain TMOT be classified as a new species, within the genus Thermotoga, as Thermotoga lettingae. PMID:12148651

  16. Influence of Inoculum Content on Performance of Anaerobic Reactors for Treating Cattle Manure using Rumen Fluid Inoculum

    Directory of Open Access Journals (Sweden)

    Sunarso

    2009-12-01

    Full Text Available Biogas productions of cattle manure using rumen fluid inoculums were determined using batch anaerobic digesters at mesophilic temperatures (room and 38.5 oC. The aim of this paper was to analyze the influence of rumen fluid contents on biogas yield from cattle manure using fluid rumen inoculums. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure (M was fed to each biodigester and mixed with rumen fluid (R and tap water (W in several ratio resulting six different M:W:R ratio contents i.e. 1:1:0; 1:0.75:0.25; 1:0.5:0.5; 1:0.25:0.75; and 1:0:1 (correspond to 0; 12.5; 25, 37.5; 50, and 100 % rumen, respectively. The research showed that, either in room temperature as well as in 38.5 C, the best performance of biogas production was obtained with rumen fluid in the range of 25-50 %. Increasing rumen content will also increase biogas production. This is suggest that, due to the optimum total solid (TS content for biogas production between 7-9 % (or correspond to more and less manure and total liquid 1:1, the rumen fluid content of 50 % will give the best performance for biogas production. However, intensively research need to be carried in further research to study interaction effect of TS and rumen content to biogas production.

  17. Modal radiation patterns of baffled circular plates and membranes

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann; Hansen, Ole; Thomsen, Erik Vilain;

    2014-01-01

    The far field velocity potential and radiation pattern of baffled circular plates and membranes are found analytically using the full set of modal velocity profiles derived from the corresponding equation of motion. The derivation is valid for a plate or membrane subjected to an external excitation...... circular radiator....

  18. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Science.gov (United States)

    Bin, Zhang; Bin, Xue; Zhigang, Qiu; Zhiqiang, Chen; Junwen, Li; Taishi, Gong; Wenci, Zou; Jingfeng, Wang

    2015-08-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all NO3--N could be removed or reduced, some amount of NO2--N were accumulated in the reactor, and N2 was the main gaseous product. SEM analysis suggested that the granules were tightly packed with a large amount of tetrad-forming organisms (TFOs); filamentous bacteria served as the supporting structures for the granules. The microbial community structure of GAO granules was differed substantially from the inoculant conventional activated sludge. Most of the bacteria in the seed sludge grouped with members of Proteobacterium. FISH analysis confirmed that GAOs were the predominant members in the granules and were distributed evenly throughout the granular space. In contrast, PAOs were severely inhibited. Overall, cultivation of the GAO granules and utilizing their denitrifying capability can provide us with a new approach of nitrogen removal and saving more energy.

  19. Analysis of the Effect of Variation of Baffle Height on the Liquid Sloshing In the Tank with CFD Approach

    Directory of Open Access Journals (Sweden)

    Suresh Patil. G. L,

    2015-12-01

    Full Text Available Sloshing is a common physical phenomenon which occurs in moving tanks with contained liquid masses, such as liquid cargo carriers, rockets, aircrafts, and the seismically excited storage tanks, dams, reactors, and nuclear vessels. The sloshing frequencies of contained liquid are essential in the analysis and design of the liquid tanks and the associated structures. In this paper an attempt made with the VOF model and considered with immiscible fluids by solving a single set of momentum equations and tracking the volume fraction of each of the fluids throughout the domain. Further investigated the effect of the vertical baffle heights on the liquid sloshing in a three-dimensional (3D rectangular tank. studied dynamic analysis of sloshing in rectangular tanks with multiple vertical baffles. ANSYS-CFX software was used to study this dynamic analysis subjected to random excitations including earthquake induced motions. analytically estimated hydrodynamic damping ratio for liquid sloshing phenomenon in a partially filled rectangular tank for baffles. They used the velocity potential formulation and linear wave theory for analytic calculations.

  20. Evaluation of anaerobic co-digestion of dairy manure with food wastes via bio-methane potential assay and CSTR reactor.

    Science.gov (United States)

    Ye, Yulin; Zamalloa, Carlos; Lin, Hongjian; Yan, Mi; Schmidt, David; Hu, Bo

    2015-01-01

    The introduction of food wastes into anaerobic digestion (AD) brings a promising scenario of increasing feedstock availability and overall energy production from AD. This study evaluated the biodegradability and methane potential from co-digestion of two typical food wastes, kitchen waste and chicken fat, with dairy manure. For single substrate, the bio-methane potential assays showed that kitchen waste had the highest methane yield of 352 L-CH4 kg(-1)-VS added, 92% more than dairy manure alone. Chicken fat at the same Volatile Solid (VS) level (2 g L(-1)) inhibited bio-methane production. Addition of kitchen waste and chicken fat to a VS percentage of up to 40% improved overall methane yield by 44% and 34%, respectively. Synergistic effect was observed when either combining two or three substrates as AD feedstock, possibly as a result of increased biodegradability of organic materials in chicken fat and kitchen waste compared with dairy manure. Addition of chicken fat improved methane yield more than kitchen waste. However, addition of chicken fat VS over 0.8 g L(-1) should be cautiously done because it may cause reactor failure due to decrease in pH. The maximum methane yield was 425 L-CH4 kg(-1)-VS, achieved at a VS ratio of 2:2:1 for kitchen waste, chicken fat, and dairy manure. Results from batch AD experiment demonstrated that supplementing dairy manure to chicken fat and/or kitchen waste improved alkalinity of substrate due to the inclusion of more titratable bases in dairy manure, and therefore stabilized the methanogenesis and substantially improved biogas yield. A mixture of substrates of kitchen waste, chicken fat, and dairy manure at a ratio of 1:1:3 was fed to a continuously stirred tank reactor operated at organic loading rates of 3.28, 6.55, and 2.18 g-COD L(-1)-day (hydraulic retention time of 20, 10, and 30 days, respectively) under mesophilic condition, and methane production rate reached 0.65, 0.95, and 0.34 L-CH4 L(-1)-reactor-day. PMID:25602155

  1. Anaerobic digestion of solid material

    DEFF Research Database (Denmark)

    Vavilin, V.A.; Lokshina, L.Y.; Flotats, X.;

    2007-01-01

    A new multidimensional (3 and 2D) anaerobic digestion model for cylindrical reactor with non-uniform influent concentration distributions was developed to study the way in which mixing intensity affects the efficiency of continuous-flow anaerobic digestion. Batch experiments reported and simulated...... improve the continuous flow reactor performance at the relatively low influent methanogenic biomass concentration. In the continuously stirred tank reactor (CSTR) there are two steady states with and without methane production at slightly different values of initial methanogenic biomass concentration....... In the system, the threshold methanogenic biomass concentration existed because of inhibition by high VFA concentration. High methanogenic biomass concentration is required for efficient anaerobic digestion of MSW in order to avoid possible inhibition due to high VFA build-up. Thus, CSTR configuration might...

  2. 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

    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 the activity of acetotrophic methanogens was uniformly distributed in all fractions. When digesting manure and lipids, an enhanced methanogenesis was detected both for particles > 200 mum and the 50-200 mum fraction. The molecular methods -temperature gradient gel electrophoresis (TGGE), cloning...... library and sequencing of 16S rDNA - showed presence of a restricted number of archaeal species in both reactors. The vast majority of clones was phylogenetically most closely related to Methanosarcina siciliae....

  3. 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)

  4. Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP).

    Science.gov (United States)

    Sponza, Delia Teresa; Uluköy, Ayşen

    2008-01-01

    The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day

  5. Anaerobe Tolerance to Oxygen and the Potentials of Anaerobic and Aerobic Cocultures for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    M.T. Kato

    1997-12-01

    Full Text Available The anaerobic treatment processes are considered to be well-established methods for the elimination of easily biodegradable organic matter from wastewaters. Some difficulties concerning certain wastewaters are related to the possible presence of dissolved oxygen. The common belief is that anaerobes are oxygen intolerant. Therefore, the common practice is to use sequencing anaerobic and aerobic steps in separate tanks. Enhanced treatment by polishing off the residual biodegradable oxygen demand from effluents of anaerobic reactors, or the biodegradation of recalcitrant wastewater pollutants, usually requires sequenced anaerobic and aerobic bacteria activities. However, the combined activity of both bacteria can also be obtained in a single reactor. Previous experiments with either pure or mixed cultures showed that anaerobes can tolerate oxygen to a certain extent. The oxygen toxicity to methanogens in anaerobic sludges was quantified in batch experiments, as well as in anaerobic reactors. The results showed that methanogens have a high tolerance to oxygen. In practice, it was confirmed that dissolved oxygen does not constitute any detrimental effect on reactor treatment performance. This means that the coexistence of anaerobic and aerobic bacteria in one single reactor is feasible and increases the potentials of new applications in wastewater treatment

  6. Potential of biohydrogen production from organic fraction of municipal solid waste (OFMSW) using pilot-scale dry anaerobic reactor.

    Science.gov (United States)

    Elsamadony, M; Tawfik, A

    2015-11-01

    A long-term evaluation of a mesophilic up-flow intermittently stirred tank reactor (UISTR) for hydrogen production from the organic fraction of municipal solid waste was investigated. UISTR was operated at five different hydraulic retention times (HRTs) of 10, 7.5, 5, 3 and 2days. This corresponds to organic loading rates (OLRs) of 18.1, 26.2, 41.3, 61.0, and 97.2gCOD/L/day, respectively. The highest volumetric H2 production of 2.20±0.19L/L/d and H2 yield of 2.05±0.33molH2/molCarbohydrate were achieved at HRT of 3days and OLR of 61.0gCOD/L/day. This revealed a higher sCOD/tCOD ratio of 0.46±0.08 and a lower particle size diameter of 307.6μm in the digestate, with a reduction of 72.0%. The maximum carbohydrates, proteins, and lipids conversions amounted to 68.2±13.0%, 37.5±6.7% and 48.6±4.7%, respectively recorded at HRT of 10days and OLR of 18.1gCOD/L/day. PMID:26218185

  7. Development of energy efficient mixing strategies in egg-shaped anaerobic reactors through 3D CFD simulation.

    Science.gov (United States)

    Hernandez-Aguilar, Eduardo; Alvarado-Lassman, Alejandro; Osorio-Mirón, Anselmo; Méndez-Contreras, Juan M

    2016-01-01

    This work describes a 3D computational fluid dynamic model, which characterizes the hydrodynamic behavior of a mixing strategy applied to egg-shaped reactors that lack a mechanical stirring device. The model is based on Navier-Stokes and material balance equations without a chemical reaction. To describe the behavior of mixing, initial water feed flows of 6, 7.5 and 9 mL s(-1) were used. An experimental validation was subsequently carried out using a pulse technique, with NaCl as a tracer. The residence time distributions were quantitatively determined. Then, the degradation process of the wastewater sludge was characterized by studying the time dependence of the dynamic viscosity, the concentration of volatile solids and the density of wastewater sludge. The data resulting were introduced into the validated model, and five feed flows from 9 to 13 mL s(-1), the best performance found was with feed flow of 11 mL s(-1). PMID:26950282

  8. Metallurgical examinations update of baffle bolts removed from operating French PWR. Microstructural investigations of a baffle to former bolt located on a high level of the internal structures

    International Nuclear Information System (INIS)

    This paper presents the microstructural investigations conducted on a cracked baffle to former bolt extracted from an upper former level of the internal structures of a French Pressurized Water Reactor (PWR). Extensive microstructural investigations using Light Microscopy, Scanning Electron Microscopy and Transmission Electron Microscopy (TEM) have been conducted to understand the degradation mechanisms of this bolt. TEM investigations have revealed neutron irradiation damage in the microstructure of the bolt such as Frank loops and cavities and/or bubbles. The number of features per unit volume as a function of diameter was determined in the head and in the shank of the bolt. The obtained results are relatively similar to those obtained for other damaged bolts extracted from PWR-type reactors and irradiated in similar conditions (dose and temperature). The irradiation damage has induced an evolution of the mechanical properties (hardening of the material), as revealed by the hardness measurements along the bolt, with a higher average value in the head (400 HV), compared to the shank (15 mm under the head), about 340 HV. The metallurgical investigations have confirmed that this bolt was damaged by Irradiation Assisted Stress Corrosion Cracking (IASCC)

  9. Microbial Communities and Their Performances in Anaerobic Hybrid Sludge Bed-Fixed Film Reactor for Treatment of Palm Oil Mill Effluent under Various Organic Pollutant Concentrations

    Directory of Open Access Journals (Sweden)

    Kanlayanee Meesap

    2012-01-01

    Full Text Available The anaerobic hybrid reactor consisting of sludge and packed zones was operated with organic pollutant loading rates from 6.2 to 8.2 g COD/L day, composed mainly of suspended solids (SS and oil and grease (O&G concentrations between 5.2 to 10.2 and 0.9 to 1.9 g/L, respectively. The overall process performance in terms of chemical oxygen demands (COD, SS, and O&G removals was 73, 63, and 56%, respectively. When the organic pollutant concentrations were increased, the resultant methane potentials were higher, and the methane yield increased to 0.30 L CH4/g CODremoved. It was observed these effects on the microbial population and activity in the sludge and packed zones. The eubacterial population and activity in the sludge zone increased to 6.4 × 109 copies rDNA/g VSS and 1.65 g COD/g VSS day, respectively, whereas those in the packed zone were lower. The predominant hydrolytic and fermentative bacteria were Pseudomonas, Clostridium, and Bacteroidetes. In addition, the archaeal population and activity in the packed zone were increased from to 9.1 × 107 copies rDNA/g VSS and 0.34 g COD-CH4/g VSS day, respectively, whereas those in the sludge zone were not much changed. The most represented species of methanogens were the acetoclastic Methanosaeta, the hydrogenotrophic Methanobacterium sp., and the hydrogenotrophic Methanomicrobiaceae.

  10. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  11. Instrumentation in anaerobic treatment - research and practice

    NARCIS (Netherlands)

    Spanjers, H.; Lier, van J.B.

    2006-01-01

    High rate anaerobic treatment reactors are able to uncouple solids and liquid retention time, resulting in high biomass concentrations. Principal advantages of anaerobic treatment include: energy efficiency, low biomass yield, low nutrient requirement and high volumetric organic loadings. In order t

  12. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

  13. 反应器类型对生物厌氧发酵产氢的影响研究进展%Progress in Studying Effects of Bio-reactor Type on Anaerobic Fermentative Bio-hydgrogen Production

    Institute of Scientific and Technical Information of China (English)

    王磊; 谢丽; 罗刚; 周琪

    2012-01-01

    Recently, fermentative hydrogen production with organic wastewater or waste becomes a research focus in the field of bio-energy production, for it is a good way of garbage disposal and energy production. The type of bio-reactor is considered to have important effects on both microbial community structures and mass transfer efficiency between biomass and substrates, which could influence the hydrogen production and stability of the process. In this paper, immobilized-and suspended-cell Hj-producing systems are compared based on biomass growth in forms of granular, bio-film, gel-entrapped bio-particle. Reactor configurations such as continuous stirred tank reactor, anaerobic sequencing batch reactor, up-flow anaerobic sludge blanket, expanded granular sludge bed, anaerobic packed bed, anaerobic fluidized-bed, hybrid bio-reactor and their impacts on bio-hydrogen production are summarized. Finally, suggestions and perspectives are proposed to provide guidance for further research.%利用有机废水或废弃物厌氧发酵制取氢气可以同时达到除废和产能的双重目的,是近年来生物质能的研究热点.产氢反应器的类型会影响反应器内产氢菌的数量和种类以及微生物与底物之间的传质作用,进而影响产氢系统的稳定性和产氢效果.对厌氧产氢悬浮细胞系统和固定化细胞系统(颗粒污泥、生物膜、微生物包埋体)保留生物量的效果进行了对比,总结了连续搅拌釜式反应器( CSTR)、厌氧序批反应器(ASBR)、上流式厌氧污泥床(UASB)、膨胀颗粒污泥床(EGSB)、厌氧填充床、厌氧流化床(AFBR)以及复合生物反应器等不同反应器类型对厌氧产氢的影响,并提出了一些建议与展望,以期为以后的研究提供指导作用.

  14. Shock-induced turbulent flow in baffle systems

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L. [Lawrence Livermore National Lab., CA (United States); Reichenbach, H. [Fraunhofer-Institut fuer Kurzzeitdynamik - Ernst-Mach-Institut (EMI), Freiburg im Breisgau (Germany)

    1993-07-01

    Experiments are described on shock propagation through 2-D aligned and staggered baffle systems. Flow visualization was provided by shadow and schlieren photography, recorded by the Cranz-Schardin camera. Also single-frame, infinite-fringe, color interferograms were used. Intuition suggests that this is a rather simple 2-D shock diffraction problem. However, flow visualization reveals that the flow rapidly evolved into a complex 3-D turbulent mixing problem. Mushroom-shaped mixing regions blocked the flow into the next baffle orifice. Thus energy was transferred from the directed kinetic energy (induced by the shock) to rotational energy of turbulent mixing, and then dissipated by molecular effects. These processes dramatically dissipate the strength of the shock wave. The experiments provide an excellent test case that could be used to assess the accuracy of computer code calculations of such problems.

  15. Optimized baffle and aperture placement in neutral beamlines

    Science.gov (United States)

    Stone, R.; Duffy, T.; Vetrovec, J.

    1983-11-01

    Most neutral beamlines contain an iron-core ion-bending magnet that requires shielding between the end of the neutralizer and this magnet. This shielding allows the gas pressure to drop prior to the beam entering the magnet and therefore reduces beam losses in this drift region. The beam losses are reduced even further by eliminating the iron-core magnet and the magnetic shielding altogether. The required bending field is supplied by current coils without the iron poles. In addition, placement of the baffles and apertures affects the cold gas entering the plasma region and the losses in the neutral beam due to re-ionization. The placement of the baffles which, determine the amount of pumping in each chamber, and the apertures, which determine the beam loss were varied. A baffler/aperture configuration is for either minimum cold gas into the plasma region or minimum beam losses, but not both.

  16. Solidification Using a Baffle in Sealed Ampoules (SUBSA)

    Science.gov (United States)

    Marin, C.; Ostrogorsky, A. G.; Volz, M.; Luz, P.; Jeter, L.; Spivey, R.; Burton, H.; Smith, G.; Knowles, T. R.; Bonner, W. A.

    2003-01-01

    Solidification Using a Baffle in Sealed Ampoules (SUBSA) will be the first materials science experiment conducted in the Microgravity Science Glovebox (MSG) Facility at the International Space Station (ISS) Alpha. The launch is schedule for May 31, 2002. Using the specially developed furnace, 10 Te and Zn-doped single crystals of InSb will be directionally solidified in microgravity. A key goal of the SUBSA investigation is to (i) clarify the origin of the melt motion in space laboratories and (ii) to reduce the magnitude of the melt motion to the point that it does not interfere with the transport phenomena. These goals will be accomplished through a special ampoule and furnace design. A disk-shaped baffle, positioned close to the freezing front, is used to reduce melt motion. Furthermore, the solidification will be visualized by using a transparent furnace, with a video camera, continuously sending images to the earth. This allows detection of bubbles and melt de-wetting that could cause surface tension driven convection. In preparation for the space experiments, 30 ground-based experiments were conducted. The results of ground based tests and numerical modeling will be presented. Based on numerical modeling, 12 mm 1D silica ampoules were selected. The small diameter ampoule favors closer placement of the baffle to the interface, without excessive radial segregation caused by forced convection while providing more damping of natural convection. The parts in the silica ampoule include 2 carbon springs made by Energy Science Laboratories, Inc., a pyrocarbon-coated graphite cylinder, pyrocarbon-coated graphite a baffle with the shaft and the InSb charge with the seed crystal grown by W.A. Bonner of Crystallod Inc.

  17. Baffled Circular Loudspeaker Array With Broadband High Directivity

    OpenAIRE

    Kolundzija, Mihailo; Faller, Christof; Vetterli, Martin

    2010-01-01

    Super-directional loudspeaker arrays can be used to achieve high directivity in a limited low-frequency range. As opposed to microphone arrays, the distance between the loudspeakers has to be relatively large, resulting in aliasing starting at relatively low frequencies. On the other hand, mounting a loudspeaker on a rigid baffle (e.g., a rigid cylinder or sphere) increases its directivity with frequency. Using super-directional array techniques at low frequencies and leveraging loudspeakers'...

  18. Effects of temperature variations on the performance of a space imaging system baffle

    Science.gov (United States)

    Haghshenas, Javad; Mohasel Afshari, Behzad

    2015-09-01

    All the star trackers must be composed of a baffle system to removes stray lights intensity. The baffle is designed to mount in front of the optical system. The performance of a star tracker is often limited by the stray light level on the detector. According to the space conditions, the baffle may deflect due to the temperature variation during the mission. Sun heat flux imposed to the baffle from one side and heat radiates from baffle to the space in all sides. In our case, the baffle is fixed to the satellite structure by four titanium screw. A finite element model has been used to modeling the baffle and temperature distribution and deflection is obtained in worst cold and hot conditions. Results show that in the worst cold condition, baffle is deflected symmetrically whereas in hot case, deflection is not symmetric and the side exposed to the sun light is elongated. Using ray tracing methods along with Monte Carlo algorithm, the baffle efficiency is obtained and compared for both cases. Results show that baffle deflections are not so extreme to force us to cover it with the MLI.

  19. Optimized baffle and aperture placement in neutral beamlines

    International Nuclear Information System (INIS)

    Most neutral beamlines contain an iron-core ion-bending magnet that requires shielding between the end of the neutralizer and this magnet. This shielding allows the gas pressure to drop prior to the beam entering the magnet and therefore reduces beam losses in this drift region. We have found that the beam losses can be reduced even further by eliminating the iron-core magnet and the magnetic shielding altogether. The required bending field can be supplied by current coils without the iron poles. In addition, placement of the baffles and apertures can affect the cold gas entering the plasma region and the losses in the neutral beam due to re-ionization. In our study we varied the placement of the baffles, which determine the amount of pumping in each chamber, and the apertures, which determine the beam loss. Our results indicate that a baffle/aperture configuration can be set for either minimum cold gas into the plasma region or minimum beam losses, but not both

  20. Fano line shapes in the branch-baffle system

    Science.gov (United States)

    Gou, Bo; Zhao, Yufang; Duan, Gaoyan; Wang, Lulu; Chen, Zhao; Cui, Runa; Zhang, Yong; Yu, Li

    2014-12-01

    A compact branch-baffle system, consisting of a branch resonator and a baffle in the metal-dielectric-metal waveguide (MDM), is proposed. A novel and efficient circuit model is developed to present the mechanisms of the plasmonic system. The model predicts two sharp asymmetric Fano line shapes, which are caused by the interactions between the branch resonator and the constructed branch-baffle resonator, exhibiting good agreement with the finite-element simulation results. The peaks of the two Fano line shapes are investigated by the relative phase method and demonstrated referring to the field distributions. The physical mechanisms of the remaining three resonances in the transmission spectrum are also carefully studied. From the analysis, the five resonances can all be precisely calculated and designed in theory. Considering the compact structure, multiple Fano resonances may be adjusted in different ways. Also, the transmittance of the Fano resonances is highly efficient (0.8). The proposed structure can have important applications in high-resolution and high-sensitivity nano-plasmonic devices.

  1. Abatement of an aircraft exhaust plume using aerodynamic baffles.

    Science.gov (United States)

    Bennett, Michael; Christie, Simon M; Graham, Angus; Garry, Kevin P; Velikov, Stefan; Poll, D Ian; Smith, Malcolm G; Mead, M Iqbal; Popoola, Olalekan A M; Stewart, Gregor B; Jones, Roderic L

    2013-03-01

    The exhaust jet from a departing commercial aircraft will eventually rise buoyantly away from the ground; given the high thrust/power (i.e., momentum/buoyancy) ratio of modern aero-engines, however, this is a slow process, perhaps requiring ∼ 1 min or more. Supported by theoretical and wind tunnel modeling, we have experimented with an array of aerodynamic baffles on the surface behind a set of turbofan engines of 124 kN thrust. Lidar and point sampler measurements show that, as long as the intervention takes place within the zone where the Coanda effect holds the jet to the surface (i.e., within about 70 m in this case), then quite modest surface-mounted baffles can rapidly lift the jet away from the ground. This is of potential benefit in abating both surface concentrations and jet blast downstream. There is also some modest acoustic benefit. By distributing the aerodynamic lift and drag across an array of baffles, each need only be a fraction of the height of a single blast fence. PMID:23343109

  2. Installation of center disk baffle into Madison Dynamo Experiment vessel

    Science.gov (United States)

    Clark, M. M.; Nornberg, M. D.; Taylor, N. Z.; Wallace, J. P.; Forest, C. B.

    2013-10-01

    The Madison Dynamo Experiment (MDE) comprises a 1 m diameter spherical chamber that contains a turbulent flow of liquid sodium driven by two counter rotating impellers. One of the goals of the MDE is to observe a magnetic field grow at the expense of kinetic energy in the liquid sodium flow. It has been found that turbulence in the MDE plays a significant and solely detrimental role in the generation of magnetic fields. The installation of an equatorial baffle and the three rotatable vanes in each hemisphere resulted in a reduction of large scale eddies in the flow and enhanced field generation. However, no self-excited field was observed. This Poster will present recent modifications made to the experiment consisting of installing a copper disk baffle in the center of the spherical vessel. The design and installation of the structure will be illustrated and discussed. Results from before and after the center disk baffle installation will be shown. Supported by NSF and DoE.

  3. Anaerobic digestion of solid material

    DEFF Research Database (Denmark)

    Vavilin, V.A.; Lokshina, L.Y.; Flotats, X.; Angelidaki, Irini

    2007-01-01

    A new multidimensional (3 and 2D) anaerobic digestion model for cylindrical reactor with non-uniform influent concentration distributions was developed to study the way in which mixing intensity affects the efficiency of continuous-flow anaerobic digestion. Batch experiments reported and simulated...... improve the continuous flow reactor performance at the relatively low influent methanogenic biomass concentration. In the continuously stirred tank reactor (CSTR) there are two steady states with and without methane production at slightly different values of initial methanogenic biomass concentration. In...... failure. According to the distributed models a plug-flow reactor with non-uniform influent concentration distributions where methanogenic and hydrolytic microorganisms are separated has significant methane production and solids removal at the relatively low influent methanogenic biomass concentration...

  4. Psychrophilic anaerobic treatment of low strength wastewaters.

    OpenAIRE

    Rebac, S.

    1998-01-01

    The main objective of this thesis was to design a high-rate anaerobic system for the treatment low strength wastewaters under psychrophilic conditions.Psychrophilic (3 to 20 °C) anaerobic treatment of low strength synthetic and malting wastewater was investigated using a single and two stage expanded granular sludge bed (EGSB) reactor system. The chemical oxygen demand (COD) removal efficiencies found in the experiments with synthetic wastewater exceeded 90 % in the single stage reactor at im...

  5. 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

    International Nuclear Information System (INIS)

    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.

  6. Sustainable Agro-Food Industrial Wastewater Treatment Using High Rate Anaerobic Process

    OpenAIRE

    Yung-Tse Hung; Michel Torrijos; Cata Saady, Noori M.; Rajinikanth Rajagopal; Joseph V. Thanikal

    2013-01-01

    This review article compiles the various advances made since 2008 in sustainable high-rate anaerobic technologies with emphasis on their performance enhancement when treating agro-food industrial wastewater. The review explores the generation and characteristics of different agro-food industrial wastewaters; the need for and the performance of high rate anaerobic reactors, such as an upflow anaerobic fixed bed reactor, an upflow anaerobic sludge blanket (UASB) reactor, hybrid systems etc.; op...

  7. Effect of dilution and L-malic acid addition on bio-hydrogen production with Rhodopseudomonas palustris from effluent of an acidogenic anaerobic reactor

    International Nuclear Information System (INIS)

    In this study, H2 was produced in a two-stage biological process: I) first stage; the dark fermentation of cheese whey wastewater, which is rich in lactose, by mixed anaerobic culture grown at thermophilic temperature in a continuously running fermentor and ii) second stage; the photo-fermentation of the residual medium by R. palustris strain (DSM 127) at 31oC under illumination of 150 W in batch mode, respectively. In the first part of the study, the effluent from the dark fermentation reactor was used either as it is (no dilution) or after dilution with distilled water at varying ratios such as 1/2 , 1/5, 1/10 (1 volume effluent/5 volume distilled water) before used in photo-fermentation experiments. In the second part of the study, L-malic acid at varying amounts was added into the hydrogen production medium in order to have L-malic acid concentrations ranging from 0 to 4 g/l. Non-diluted and pre-diluted mediums with or without L-malic acid addition were also tested for comparison purpose (as controls). Prior to the hydrogen production experiments, all samples were subjected to pH adjustment, (pH 6.7) and sterilized by autoclave at 121oC for 15 min. In regards to the experiments in which the effect of dilution of the effluent from dark fermentation was studied, it was observed that dilution of the effluent from dark fermentation resulted in much better hydrogen productions. Among the dilution rates used, the experiments operated with 1/5 dilution ratio produced the best hydrogen production (241 ml H2/ g CODfed). On the other hand, it was seen that the mixing the effluent with L-malic acid (0 - 4 g/l) at increasing ratios (studied from 0% L-malic acid up to 100% by volume in the mixture) had further positive effect and improved the hydrogen production. The bioreactors containing only L-malic acid media resulted in the best hydrogen production (438 ml H2 / g CODfed). It was found that, undiluted raw cheese whey wastewater effluent from dark hydrogen production

  8. Relay telescope including baffle, and high power laser amplifier utilizing the same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  9. Thermoeconomic optimization of baffle spacing for shell and tube heat exchangers

    International Nuclear Information System (INIS)

    Despite the importance of thermoeconomic analysis in shell and tube heat exchanger design, the determination of the optimum baffle spacing by using the thermoeconomic analysis is usually neglected. On the other hand, baffle spacing is one of the most important parameters used in the design of shell and tube heat exchangers, and there is no precise criterion for the determination of baffle spacing in the literature. In this study, thermoeconomic analysis is used to determine the optimum baffle spacing, accompanied by an example of such an optimization of baffle spacing for a shell and tube heat exchanger. The results of this example are then used to demonstrate how the optimum ratio of baffle spacing to shell diameter is determined precisely and affected by the varying values of the geometrical parameters. Finally, the results are compared to those obtained by classical approaches

  10. NUMERICAL SIMULATION OF FLUID FLOW BEHAVIOUR ON SCALE UP OF OSCILLATORY BAFFLED COLUMN

    OpenAIRE

    WAH KENG SERN; MOHD SOBRI TAKRIFF; SITI KARTOM KAMARUDIN; MEOR ZAINAL MEOR TALIB; NURUL HASAN

    2012-01-01

    The fluid dynamics of oscillatory flow in a baffled column of 145 mm diameter was investigated numerically in this work. This numerical simulation was carried out by a 2D laminar unsteady solver using CFD package Fluent® 6.3. From the simulation, data on surface velocity were collected and velocity ratio was calculated to determine the intensity of mixing which were the main operating parameters in oscillatory flow in a baffled column. The suitable operating parameters of oscillatory baffled ...

  11. Dynamic Effect of Discharge Flow of a Rushton Turbine Impeller on a Radial Baffle

    OpenAIRE

    J. Kratěna; I. Fořt; O. Brůha

    2001-01-01

    This paper presents an analysis of the mutual dynamic relation between the impeller discharge flow of a standard Rushton turbine impeller and a standard radial baffle at the wall of a cylindrical mixing vessel under turbulent regime of flow of an agitated liquid. A portion of the torsional moment of the baffle corresponding to the region of the force interaction of the impeller discharge stream and the baffle is calculated under the assumption of constant angular momentum in the flow region b...

  12. Particle contamination from Martin Optical Black. [in design of barrel baffle of Infrared Astronomical Satellite

    Science.gov (United States)

    Young, P. J.; Noll, R.; Andreozzi, L.; Hope, J.

    1981-01-01

    The design of the barrel baffle of the Infrared Astronomical Satellite (IRAS) Optical Subsystem to minimize production of particulate contamination is described. The configuration of the 50-inch long, 28.5-inch diameter baffle required pop-rivet assembly after coating with Martin Optical Black for stray light suppression. An experiment to determine the contamination produced at assembly led to the modification of the baffle construction to preclude such damage to the coated surfaces.

  13. ANALYSIS OF HELICAL BAFFLE HEAT EXCHANGER FOR OPTIMUM HELIX ANGLE THROUGH NUMERICAL SIMULATIONS

    OpenAIRE

    Roktutpal Borah; R.K Chitharthan

    2015-01-01

    Heat exchangers are very important heat & mass exchange apparatus in many industries like electric power generation, chemical industries, oil refining, etc. The most common heat exchangers used are shell-&-tube heat exchangers (STHXs). Among different kinds of baffles used in STHX, segmental baffles are most commonly used in conventional STHXs to support tubes & change fluid flow direction. But, conventional heat exchangers with segmental baffles in shell-side have some drawbacks ...

  14. Experimental investigation of shell-and-tube heat exchanger with a new type of baffles

    Science.gov (United States)

    Wang, Yingshuang; Liu, Zhichun; Huang, Suyi; Liu, Wei; Li, Weiwei

    2011-07-01

    A shell-and-tube heat exchanger with new type of baffles, is designed, fabricated and tested. The experimental investigation for the proposed model and the original segmental baffle heat exchanger are conducted. The operation performances of the two heat exchangers are also compared. The results suggest that, under the same conditions, the overall performance of the new model is 20-30% more efficient than that of the segmental baffle heat exchanger.

  15. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  16. Thermal design of retroreflective stray light fore-baffles for spaceborne optical systems

    Science.gov (United States)

    Schneider, Edward

    2001-03-01

    The use of stray light fore-baffles in space-borne optical systems solves the problem of protecting the optical system from unwanted radiation. However, this introduces the problem of adding a large area black cavity at the system entrance aperture, and this cavity will run hot due to capture of solar, planetary albedo, and planetary emission radiation. The optical system may need to be baffled by a cool shield to keep system absolute temperatures sufficiently low. Alternately, a reflecting baffle system can be used that retro-reflects the input environment radiation. This reduces absorbed heat loads by the baffle system and reduces system absolute temperature levels.

  17. EFFECT OF VERTICAL BAFFLES ON PARTICLE MIXING AND DRYING IN FLUIDIZED BEDS OF GROUP D PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Chung Lim Law; Siti Masrinda Tasirin; Wan Ramli Wan Daud; Derek Geldart

    2003-01-01

    This study reports the effect of vertical baffles on the group D powder mixing and drying characteristics in a batch fluidized bed dryer. Results obtained in this study showed that operating the fluidized bed dryer with vertical baffles gave better particle mixing. This is due to the fact that the vertical baffles acted to limit the growth of small bubbles into large bubbles and the small bubbles caused more vigorous mixing in the bed of particles before finally erupting at the bed surface. Thus, insertion of vertical baffles is a useful way to process group D particles in a fluidized bed, especially when the fluidized bed is large.

  18. Further analysis of the effects of baffles on combustion instability. [computer techniques

    Science.gov (United States)

    Oberg, C. L.; Schuman, M. D.

    1975-01-01

    A computerized analytical model, developed to predict the effects of baffles on combustion instability, was modified in an effort to improve the ability to properly predict stability effects. The model was modified: (1) to replace a single spatially-averaged response factor by separate values for each baffle compartment; (2) to calculate the axial component of the acoustic energy flux, and (3) to permit analysis of traveling waves in a thin annular chamber. Allowance for separate average response factors in each baffle compartment was found to significantly affect the predicted results. With this modification, an optimum baffle length was predicted which gave maximum stability.

  19. Improvement activities for the maintenance of Baffle Former Bolts

    International Nuclear Information System (INIS)

    Baffle Former Bolts (BFBs) in PWR nuclear plant have the possibility to be cracked due to Irradiation Assisted Stress Corrosion Cracking (IASCC). The maintenance guideline for BFBs had been established from Thermal and Nuclear Power Engineering Society in 2000, and BFBs have been maintained in accordance with this maintenance rules. Recently, the new edition of this guideline has been published in order to reflect latest IASCC data and more precise stress evaluation of BFB into maintenance rules. The summary of the revised contents and these improvement activities are introduced in this paper. (author)

  20. Desempenho de processo anaeróbio em dois estágios (reator compartimentado seguido de reator UASB) para tratamento de águas residuárias de suinocultura Performance of two-stage anaerobic process (baffled reactor (ABR) followed by an upflow sludge blanket reactor (UASB)) treating swine wastewater

    OpenAIRE

    Gracie F. R. Fernandes; Roberto A. de Oliveira

    2006-01-01

    Avaliou-se o efeito das águas residuárias de suinocultura com concentrações de sólidos suspensos totais em torno de 6.000 mg L-1 (DQOtotal variando de 7.557 a 11.640 mg L-1) no desempenho de processo anaeróbio em dois estágios compostos por reator compartimentado (ABR) e reator de fluxo ascendente com manta de lodo (UASB), instalados em série, em escala-piloto (volumes de 530 e 120 L, respectivamente), submetidos a tempos de detenção hidráulica (TDH) de 56 a 18 h no primeiro reator e de 13 a ...

  1. Hydraulic jump basins with wedge-shaped baffles

    Institute of Scientific and Technical Information of China (English)

    Ashraf Fathy ELLAYN; Zhi-lin SUN

    2012-01-01

    This laboratory study deals with the hydraulic jump properties for an artificially roughened bed with wedge-shaped baffle blocks,The experiments were conducted for both smooth and rough beds with a Froude number in the range of 3.06≤F1≤10.95 and a relative bed roughness ranging 0.22≤KR≤1.4.The data from this study were compared with those of rectangular baffle blocks.New experimental formulae were developed for determining the sequent depth ratio and the hydraulic jump length in terms of the inflow Froude number and relative bed roughness.Bélangers jump equation of a rectangular channel was extended to account for the implications of the bed shear stress coefficient attributable to channel bed roughness.It was found that,in comparison with the smooth bed,the wedge-shaped bed roughness reduced the sequent depth of the hydraulic jump by approximately 16.5% to 30% and the hydraulic jump length by approximately 30% to 53%.

  2. Application of Anaerobic Digestion Model No .1 combining hydrodynamics in UASB reactor%结合水动力学的厌氧消化1号模型在UASB反应器中的应用

    Institute of Scientific and Technical Information of China (English)

    何佳; 霍颖超; 张泽; 穆杨; 曾建雄

    2014-01-01

    建立了新型的以厌氧消化1号模型为基础的对流扩散模型来模拟升流式厌氧污泥床反应器,在此模型中同时考虑了水动力学及生化动力学。模型涉及的偏微分方程借助中心有限差分法在M atlab中编程进行求解。示踪剂实验与两组有机负荷冲击实验分别用于验证对流扩散模型的水动力学及生化动力学,结果显示模拟数据与实验数据能很好地吻合。此外,所建立的模型还能反映不同高度处的反应器状态,借助这个优势可以在反应器遭受异常情况时进行预警。%A novel Anaerobic Digestion Model No .1 based dispersive model was developed to simulate the upflow anaerobic sludge blanket reactor (UASB) ,in which both hydrodynamics and bio-dynamics were taken into account .The partial differential equations in the model was solved by finite difference method in Matlab . A tracer study and two loading-shock experiments were used to validate the reactor's hydrodynamics and bio-dynamics ,respectively .The simulated data match the experimental data very well . Besides ,the developed model can reflect the reactor's status at different heights ,w hich makes it possible to give early warnings in abnormal situations .

  3. Strategy and calculations for the design of baffles for Wolter Type II telescopes

    Science.gov (United States)

    Mangus, John D.

    Spaceflight, stellar pointing telescopes require baffle systems to define the field of view and protect this observational area from stray and scattered light. In the case of near normal incidence telescope systems, the problem consists in controlling the stray/scattered radiation reaching the image plane when circular plates, the primary and secondary mirrors, are the imaging elements. The case addressed in this paper is quite different in that it involves baffling two conical surfaces, i.e., the primary and secondary mirrors of a Wolter Type II telescope. A strategy is described for systematically moving through the telescope system and establishing criteria for placement of baffles. Calculations are given which determine the size and number of permitted baffles as a function of practical physical parameters. Clear options are given for the design of minimum baffle lengths to meet packaging constraints.

  4. Velocity profiles between two baffles in a shell and tube heat exchanger

    Science.gov (United States)

    Chang, Tae-Hyun; Lee, Chang-Hoan; Lee, Hae-Soo; Lee, Kwon-Soo

    2015-06-01

    Heat exchangers are extensively utilized for waste heat recovery, oil refining, chemical processing, and steam generation. In this study, velocity profiles are measured using a 3D particle image velocimetry (PIV) system betweentwo baffles in a shell and tube heat exchanger for parallel and counter flows. The PIV and computational fluid dynamics results show the occurrence of some strong vectors near the bottom. These vectors are assumed due to the clearance between the inner tubes and the front baffle. Therefore, the major parts of the vectors are moved out through the bottom opening of the rear baffle, and other vectors produce a large circle between the two baffles. Numerical simulations are conducted to investigate the effects of the baffle on the heat exchanger using the Fluent software. The k-ɛ turbulence model is employed to calculate the flows along the heat exchanger

  5. Appraising the performance of a baffled solar air heater with external recycle

    International Nuclear Information System (INIS)

    Highlights: • Thermal performance for a baffled solar air heater with external recycle is studied. • Applying external recycle boosts the energy efficiency of the air heater remarkably. • Applying fins and baffles under external recycle enhances energy efficiency. • Utilizing baffles at high recycle ratios and mass flow rates declines ηeff. • Utilizing only fins at high mass flow rates and recycle ratios is well-organized. - Abstract: This study aims at appraising the possibility of enhancing thermal performance of an upward-type single pass solar air heater by utilizing fins and baffles over the absorber plate as well as applying external recycle device simultaneously under various parametric conditions. The energy and effective efficiencies analysis is used as criteria to evaluate the performance. The investigation is carried out for three cases: simple absorber plate, absorber plate with fins and absorber plate with fins and baffles. The achieved results disclose that attaching both fins and baffles to the absorber plate under external recycling operation is an effective method to boost the energy efficiency notably. In contrast, the effective efficiency analysis reveals that attaching both fins and baffles at high mass flow rates and recycle ratios leads to considerable decline in effective efficiency. Parametric studies on variation of baffle parameters illustrate that increasing the baffles width as well as declining the distance between baffles under turbulent flow regime are not economically feasible owing to extremely increase of the pressure drop and required pump work. In a nutshell, it is found that utilizing only fins under external recycle application at high mass flow rates and recycle ratios is an attractive option

  6. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C......% of the added C-12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C-12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C-12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation......Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...

  7. CARBOHYDRATE ENHANCED BIOFILM GROWTH IN ANAEROBIC FLUIDIZED BED REACTOR TREATING SYNTHETIC WASTEWATER = EFEITO DA ADIÇÃO DE CARBOIDRATOS NO CRESCIMENTO DE BIOFILME EM REATOR ANAERÓBIO DE LEITO FLUIDIFICADO

    Directory of Open Access Journals (Sweden)

    Renata Medici Frayne Cuba

    2010-01-01

    Full Text Available Biofilm dynamics in anaerobic fluidized bed reactor was studied since start-up during a 600-day operation time. Specific methanogenic activity tests revealed gas production by the anaerobic biomass since 30th operation day. Scanning Electron Microscopy (SEM micrographs permitted to verify three bacterial development stages depending on the organic loading imposed to the system. Increasing of organic loading caused methanogenic specific activity depletion due to diffusion resistance through anaerobic biofilm. With maximum organic loading of 28.5 kg COD.m-3.day-1, almost 10% of the volatile solids fixed in inert particle surface were detected as polymeric extracellular material. = A dinâmica do biofilme em um reator anaeróbio de leito fluidificado foi estudada durante 600 dias desde a partida do sistema. Testes de atividade metanogênica específica revelaram produção de gás pela biomassa anaeróbia desde o trigésimo dia de operação. Microfotografias obtidas com microscópio eletrônico de varredura (MEV permitiram verificar três estágios no desenvolvimento das bactérias, dependendo da carga orgânica imposta ao sistema. O aumento de carga orgânica causou a diminuição da atividade metanogênica específica devido à resistência à difusividade ao longo do biofilme anaeróbio. Com carga orgânica máxima de 28,5 kg COD. m-3.dia-1, aproximadamente 10% dos sólidos voláteis aderidos na superfície das partículas inertes foi identificado como material polimérico extracelular.

  8. Thermal analysis of the baffle structure of the Solar Space Telescope

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in diameter.It observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray light.The baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control design.In this study,the compatibility analysis of the thermal effect of baffle structures in SST is performed.The GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are derived.The objective and method of the compatibility analysis are determined.With the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3’ tilt angle and 16’ tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray light.The design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3’ are successfully designed.This paper presents the relationship between the thermal control design and stray light elimination plan in the SST.The aims of the optimal design of the baffle structure of SST are reached.The thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

  9. Oxygen Effects in Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Deshai Botheju

    2009-10-01

    Full Text Available Interaction of free oxygen in bio-gasification is a sparsely studied area, apart from the common argument of oxygen being toxic and inhibitory for anaerobic micro-cultures. Some studies have, however, revealed increased solubilisation of organic matter in the presence of some free oxygen in anaerobic digestion. This article analyses these counterbalancing phenomena with a mathematical modelling approach using the widely accepted biochemical model ADM 1. Aerobic oxidation of soluble carbon and inhibition of obligatory anaerobic organisms are modelled using standard saturation type kinetics. Biomass dependent first order hydrolysis kinetics is used to relate the increased hydrolysis rate with oxygen induced increase in biomass growth. The amended model, ADM 1-Ox (oxygen, has 25 state variables and 22 biochemical processes, presented in matrix form. The computer aided simulation tool AQUASIM 2.1 is used to simulate the developed model. Simulation predictions are evaluated against experimental data obtained using a laboratory batch test array comprising miniature anaerobic bio-reactors of 100 ml total volume each, operated under different initial air headspaces giving rise to the different oxygen loading conditions. The reactors were initially fed with a glucose solution and incubated at 35 Celsius, for 563 hours. Under the oxygen load conditions of 22, 44 and 88 mg/L, the ADM1-Ox model simulations predicted the experimental methane potentials quite adequately. Both the experimental data and the simulations suggest a linear reduction of methane potential with respect to the increase in oxygen load within this range.

  10. Modeling of Alcator C-Mod Divertor Baffling Experiments

    Energy Technology Data Exchange (ETDEWEB)

    D. P. Stotler; C. S. Pitcher; C. J. Boswell; T. K. Chung; B. LaBombard; B. Lipschultz; J. L. Terry; R. J. Kanzleiter

    2000-11-29

    A specific Alcator C-Mod discharge from the series of divertor baffling experiments is simulated with the DEGAS 2 Monte Carlo neutral transport code. A simple two-point plasma model is used to describe the plasma variation between Langmuir probe locations. A range of conductances for the bypass between the divertor plenum and the main chamber are considered. The experimentally observed insensitivity of the neutral current flowing through the bypass and of the D alpha emissions to the magnitude of the conductance is reproduced. The current of atoms in this regime is being limited by atomic physics processes and not the bypass conductance. The simulated trends in the divertor pressure, bypass current, and D alpha emission agree only qualitatively with the experimental measurements, however. Possible explanations for the quantitative differences are discussed.

  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. Anaerobic Digestion of Paper Mill Wastewater

    OpenAIRE

    Shreeshivadasan Chelliapan; Siti Baizura Mahat; Md. Fadjil Md. Din; A. Yuzir; Othman, N.

    2012-01-01

    In general, paper mill wastewater contains complex organic substances which could not be treated completely using conventional treatment processes, e.g. aerobic processes. As a result, anaerobic technology is a promising alternative for paper mill wastewater treatment due to its ability to degrade hard organic compounds. In the present study, treatment of paper mill wastewater using a stage anaerobic reactor was investigated. The more specific objectives of this study were to confirm whether ...

  13. 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)

  14. Industrially Experimental Investigations and Development of the Curve-ROD Baffle Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    严良文; 吴金星; 王志文

    2004-01-01

    The conventional heat exchanger with segmental baffles is prone to bring forth fluid-induced vibration of heat transfer tubes and increase the pressure drop of shell-side greatly at higher fluid flow velocity. In order to avoid the above defects, the ROD-baffle heat exchanger has been developed. However, its collocation of heat transfer tubes is conventionally in square, which leads to fewer heat transfer area per unit volume. Based on the ROD-baffle heat exchanger, a new type curve-ROD baffle has been developed, and an industrial investigation of the curve-ROD baffle heat exchanger with normal triangular collocation has been carried into execution. In this paper, two equations using the Reynolds number were acquired to predict the heat transfer coefficients of the shell-side and tubeside. The experimental results show that the shell-side heat transfer and pressure drop characteristics of the curve-ROD baffle heat exchanger are superior to those of the segmental baffle one.

  15. Dynamic Stress Affecting the Radial Baffle on an Industrial Mixing Unit with a Pitched Blade Impeller

    Directory of Open Access Journals (Sweden)

    J. Kratěna

    2000-01-01

    Full Text Available This paper presents a study of dimensioning under fatigue stress of a standard radial baffle in an industrial mixing unit (T = 5 m with a pitched blade impeller under a turbulent regime of flow of an agitated liquid. The fatigue stress of the radial baffle is calculated from the known experimentally determined distribution of the dynamic pressure affecting the standard radial baffle in a pilot plant agitated system. Asymmetrical distribution of the dynamic pressure along the height of the baffle significantly affects the thickness of the baffle as well as the dimensions of the doublefillet weld fixing the baffle to the vessel wall. Our results are valid for standard pitched blade impellers with four or six inclined blades (D/T = 1/3, a = 45° and off-bottom clearances h/T = 0.2, 0.35 and 0.5 pumping liquid downwards in a cylindrical mixing vessel with a flat bottom and four baffles (b/T = 0.1 when the Reynolds number exceeds ten thousand.

  16. Alternativas para o controle de emissões odorantes em reatores anaeróbios tratando esgoto doméstico Alternatives for the control of odorous emissions in anaerobic reactors treating domestic wastewater

    Directory of Open Access Journals (Sweden)

    Carlos Augusto de Lemos Chernicharo

    2010-09-01

    Full Text Available Esta nota técnica busca consolidar as principais características, vantagens e desvantagens dos métodos usualmente empregados para o controle de emissões odorantes, discorrendo criticamente acerca da aplicabilidade de cada um dos métodos para o tratamento de odores em estações de tratamento de esgoto doméstico. Verificou-se que vários métodos são sofisticados, de elevado custo e, muitas vezes, não aplicáveis ao tratamento de odores emitidos em reatores anaeróbios tratando esgoto doméstico. Uma análise qualitativa dos vários métodos indica que a combustão direta e os processos bioquímicos são os que reúnem o maior conjunto de vantagens para o tratamento de gases residuais emitidos em reatores anaeróbios.This technical note aims at consolidating the main characteristics, advantages and disadvantages of the methods usually applied to the control of odorous emissions, with a critical analysis upon the applicability of each method to the treatment of odours in treatment plants of domestic wastewater. It was verified that several methods are sophisticated, present high cost, and are often non-applicable to the treatment of odour emissions from anaerobic reactors treating domestic wastewater. The qualitative analysis of the various methods points out that direct combustion and biochemical processes gather more advantages for the treatment of waste gases produced in anaerobic reactors.

  17. 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

    OpenAIRE

    Mário S. de Abreu Neto; Roberto A. de Oliveira

    2009-01-01

    Neste trabalho, avaliou-se o efeito das águas residuárias de suinocultura, com concentrações médias de sólidos suspensos totais variando de 4.591 a 13.001 mg L-1, no desempenho de processo anaeróbio, em dois estágios, compostos por reator compartimentado (ABR) e reator de fluxo ascendente com manta de lodo (UASB), instalados em série, em escala- -piloto (volumes de 530 e 120 L, respectivamente), submetidos a tempos de detenção hidráulica (TDH) de 60; 36 e 24 h no primeiro reator, e de 13,6; 8...

  18. Dynamic Stress Affecting the Radial Baffle on an Industrial Mixing Unit with a Pitched Blade Impeller

    OpenAIRE

    J. Kratěna; I. Fořt; O. Brůha; Růžička, M. (Marek)

    2000-01-01

    This paper presents a study of dimensioning under fatigue stress of a standard radial baffle in an industrial mixing unit (T = 5 m) with a pitched blade impeller under a turbulent regime of flow of an agitated liquid. The fatigue stress of the radial baffle is calculated from the known experimentally determined distribution of the dynamic pressure affecting the standard radial baffle in a pilot plant agitated system. Asymmetrical distribution of the dynamic pressure along the height of the ba...

  19. Optimum design of the carbon fiber thin-walled baffle for the space-based camera

    Science.gov (United States)

    Yan, Yong; Song, Gu; Yuan, An; Jin, Guang

    2011-08-01

    The thin-walled baffle design of the space-based camera is an important job in the lightweight space camera research task for its stringent quality requirement and harsh mechanical environment especially for the thin-walled baffle of the carbon fiber design. In the paper, an especially thin-walled baffle of the carbon fiber design process was described and it is sound significant during the other thin-walled baffle design of the space camera. The designer obtained the design margin of the thin-walled baffle that structural stiffness and strength can tolerated belong to its development requirements through the appropriate use of the finite element analysis of the walled parameters influence sensitivity to its structural stiffness and strength. And the designer can determine the better optimization criterion of thin-walled baffle during the geometric parameter optimization process in such guiding principle. It sounds significant during the optimum design of the thin-walled baffle of the space camera. For structural stiffness and strength of the carbon fibers structure which can been designed, the effect of the optimization will be more remarkable though the optional design of the parameters chose. Combination of manufacture process and design requirements the paper completed the thin-walled baffle structure scheme selection and optimized the specific carbon fiber fabrication technology though the FEM optimization, and the processing cost and process cycle are retrenchment/saved effectively in the method. Meanwhile, the weight of the thin-walled baffle reduced significantly in meet the design requirements under the premise of the structure. The engineering prediction had been adopted, and the related result shows that the thin-walled baffle satisfied the space-based camera engineering practical needs very well, its quality reduced about 20%, the final assessment index of the thin-walled baffle were superior to the overall design requirements significantly. The design

  20. Anaerobic wastewater treatment of high salinity wastewaters: impact on bioactivity and biomass retention

    OpenAIRE

    S. Ismail

    2013-01-01

    Anaerobic sludge bed reactor systems like the upflow anaerobic sludge blanket (UASB) and expended granular sludge bed (EGSB) reactors are currently the mostly applied high-rate reactor systems for anaerobic wastewater treatment. The success of both systems has changed the world conception of wastewater treatment with energy recovery being an intrinsic part of the treatment process, avoidance of excess sludge problems and extremely low space requirement. Nevertheless, while broadening the UASB...