Academic literature on the topic 'Anaerobic batch reactor'

This study aimed to set up an anaerobic treatment system for the treatment of wastewater derived from the farming of African Catfish (Clarias gariepinus). In this current study, anaerobic treatment of wastewater derived from the African catfish (Clarias gariepinus) aquaculture was conducted in semi-continuous reactor as well as batch reactor under mesophilic condition at 35 °C. The results revealed that the semi-continuous reactors generated higher biogas yield (69.27 mL/g VS) compared with batch reactor (22.81 mL/g VS). High conversion rate of anaerobic treatment process operated in semi-continuous reactor was also represented in higher percentage of COD removal (82.6%) compared with batch reactor which was only 62.76%. After conducting anaerobic treatment process on the wastewater derived from the catfish aquaculture, some parameters including total dissolved solids (TDS), Phosphorous (P), potassium (K) and electrical conductivity (Ec) increased in both batch and semi-continuous reactors. Batch reactors showed TS, VS and COD reduced from 0.23%, 42.88% and 1440 mg/L to 0.137 ± 0.024%, 22.78 ± 19.44% and 536.32 ± 11.27 mg/L, respectively. The results obtained from semi-continuous reactor revealed that TS, VS and COD reduced from 0.23%, 42.88% and 1440 mg/L to 0.219%, 24.353% and 250.61 mg/L, respectively. This study is highly significant for the environmental protection system.

This study evaluates the joint effects of erythromycin–sulfamethoxazole (ES) combinations on anaerobic treatment efficiency and the potential for antibiotic degradation during anaerobic sequencing batch reactor operation. The experiments involved two identical anaerobic sequencing batch reactors. One reactor, as control unit, was fed with synthetic wastewater while the other reactor (ES) was fed with a synthetic substrate mixture including ES antibiotic combinations. The influence of ES antibiotic mixtures on chemical oxygen demand (COD) removal, volatile fatty acid production, antibiotic degradation, biogas production, and composition were investigated. The influent antibiotic concentration was gradually increased over 10 stages, until the metabolic collapse of the reactors, which occurred at 360 days for the ES reactor. The results suggest that substrate/COD utilization and biogas/methane generation affect performance of the anaerobic reactors at higher concentration. In addition, an average of 40% erythromycin and 37% sulfamethoxazole reduction was achieved in the ES reactor. These results indicated that these antibiotics were partly biodegradable in the anaerobic reactor system.

HighlightsA novel single-jet mixing system was designed for ASBR digesters.Mixing energy was reduced to the point that solids were only partially suspended in the reactor vessel.The partial mixing system increased effluent quality as measured by suspended solids content.The partial mixing system increased solids retention, allowing hydraulic retention time (HRT) to be reduced to at least 7.5 days while maintaining solids retention time (SRT) above 100 days.The partial mixing system did not reduce biogas production rate nor biogas yield.Abstract. An anaerobic sequencing batch reactor (ASBR) is a high-rate anaerobic digestion system ideally suited for the treatment of liquids with high organic strength and low solids content. Biota are retained in an ASBR by settling solids prior to decanting effluent from the top of the reactor. Solids retention time (SRT) can be managed separately from hydraulic retention time (HRT) in an ASBR. One problem encountered with ASBRs is poor solids retention due to inefficient solids settling. A novel mixing system in which solids are only partially mixed in the reactor prior to decanting was investigated in a series of three experiments. A battery of six 30 L ASBR reactors were fed a mixture of dilute swine manure (0.30% TS, 0.20% VS) and raw glycerol. In a side-by-side comparison of two reactors operated at an organic loading rate (OLR) of 0.30 g COD L-1 d-1 with 15-day HRT and two feeding cycles per day, the partially mixed reactor outperformed the fully mixed reactor as measured by effluent quality (130 vs. 350 mg VSS L-1), SRT (354 vs. 52 days), and VS removal efficiency (88% vs. 79%). In a replicated study of five reactors operated at 0.31 g COD L-1 d-1 OLR, 15-day HRT, and two feeding cycles per day before and after switching from full to partial mixing, the partially mixed reactors showed significantly (p = 0.05) better performance as measured by effluent quality (100 vs. 382 mg VSS L-1), SRT (760 vs. 72 days), and VS removal efficiency (85% vs. 71%). Biogas production did not significantly change with the change from full to partial mixing in the five replicated reactors, i.e., average biogas yield was 0.81 and 0.77 L biogas g-1 COD with partial and full mixing, respectively. Effluent quality, SRT, VS removal efficiency, and biogas yield did not significantly change when the OLR was increased from 0.31 to 0.62 g COD L-1 d-1 and HRT was reduced from 15 to 7.5 days in a replicated study of six partially mixed reactors. A mass balance of COD across the six partially mixed reactors showed that endogenous respiration of retained biomass accounted for approximately 50% of the biogas produced by an ASBR with SRT exceeding 400 days. Keywords: Anaerobic digestion, Anaerobic sequencing batch reactor, ASBR, Biogas, Glycerol, Hydraulic retention time, Mixing, Operation, Performance, Solids retention time, Swine manure.

Anaerobic fermentation is a suitable method of energetic and material utilisation of waste coming from restaurants and canteens. Laboratory experiments of wet anaerobic fermentation were performed in a continuous reactor and in batch reactors under mesophilic conditions. Effects of hydraulic retention time, organic loading rate, period of feeding and recirculation of digestate were examined in the continuous reactor. Effects of substrate pre-treatment (crushing, heating, freezing) were examined in the batch reactors. Degree of substrate degradation ranged between 83–85% within hydraulic retention time of 2–30 days. Appropriate organic loading rate was found in the range 2–3 kg of volatile solids per m3/day. Recirculation of digestate (both an inoculum for fresh substrate and replacement of fresh water supply) caused an increase in ammonia concentration and led to immediate inhibition of the process. The results further showed a positive effect of substrate pre-treatment in the initial phase of fermentation. However, degree of degradation did not show a significant increase for the period of 20 days of fermentation.    

Sulphur dioxide gas is one of most contaminating gas in the air. Sulphur gas can be produced by mining activities. Sulphur gas will be harmful if bond with CO2 to form as Sulphur Dioxide. To reduce the Sulphur Dioxide gas concentration we must inhibite the sulphur gas formation from mining activities. The inhibition of sulphur gas could be done by reduce the sulphate concentration in acid mine drainage. One of important factor that influencing the reduce of sulphate is COD/SO42- ratio. The effect of COD/SO42- ratio on bacterial growth and sulfate removal process can be investigated with anaerobic batch reactor. The laundry septic tank sediments were inoculated on an anaerobic batch reactor which were contacted with artificial coal acid mine water wastes with 1000 sulfate concentrations and 2000 mg SO42- /L. In an anaerobic batch reactor there are five reactors with variations of COD / SO42-1.0, 1.5, 2.0, 4.0, and 8.0 ratios. Efficiency ratio and the best sulfate removal rate is in reactor ratio 2.0 with value efficiency of 46.58% and a reduction rate of 29.128 mg / L.day in an anaerobic batch reactor. The efficiency of the removal rate decreased when the COD / SO42->2.0 ratio decreased. The fastest pH decline was in the COD/SO42-8.0 ratio variation in the anaerobic batch reactor and. The COD / SO42-ratio can help the sulfate reduction process in the optimum value by affecting the sulfate-reducing bacterial metabolism in the balance of the acceptor and the electron donor.

Two laboratory-scale sequencing batch reactors were used to study biological treatment of carbon and nitrogen in a new combined anaerobic-aerobic system. Piggery wastewater was used as a model effluent. The anaerobic reactor, fed with raw wastewater and nitrite/nitrate recycling from the aerobic reactor, carried out denitrification and anaerobic digestion of organic carbon. In the aerobic reactor, organic carbon removal and nitrification of ammonia to mainly nitrite occurred. Three recycle-to-influent ratios from1 to 3 were tested. The higher the recycle-to-influent ratio, the lower the concentrations of nitrogen oxides in the final effluent. Carbon removal efficiency was quite stable, whatever the ratio. However, the effect of this ratio was attenuated because of denitrification in the aerobic reactor, which increased the performances of the process. The use of sequencing batch reactors was essential to apply the configuration proposed, in order to combine denitrification and methanogenesis that require antagonistic conditions.

Sampah merupakan masalah utama disetiap kota besar di indonesia. Tumpukan sampah menghasilkan air lindi dengan kandungan organik yang tinggi. Beban organik yang tinggi dan meningkatnya laju alir lindi memerlukan kolam aerasi yang luas untuk mengolah lindi. Salah satu metode pengolahan air lindi yang tepat dan efisien dengan menggunakan proses anaerobik. Anaerobic Fludized Bed Reaktor (AFBR) merupakan salah satu reactor anaerobic dengan efisiensi tinggi. Zeolit digunakan sebagai media imobilisasi bakteri untuk meningkatkan efisiensi pengolahan secara anaerobic pada reactor AFBR. Penyesuaian model kinetika dilakukan pada tahap awal menggunakan data reactor fase batch untuk diaplikasikan pada AFBR fase continyu. Model kinetika untuk mengevaluasi pengaruh Hydraulic Retention Time (HRT) terhadap removal Chemical Oxygen Demand (COD) AFBR dengan zeolit sebagai media imobilisasi. Eksperimen dilakukan dalam tiga fase, yaitu fase batch, fase start-up, dan fase steady state. Fase batch bertujuan untuk menentukan konstanta model kinetika. Fase start-up bertujuan untuk memverifikasi konstanta model yang ditentukan dengan data batch pada AFBR saat masa start up. Fase steady state bertujuan untuk mengevaluasi pengaruh HRT selama reactor beroperasi. Reaktor AFBR mencapai kondisi steady state tercepat pada HRT 10 dengan removal COD 73,40%. Hal ini membuktikan bahwa mikroorganisme tidak mengalami washout bahkan pada laju beban organik yang lebih tinggi sehingga mikroorganisme dapat menstabilkan populasinya. Data menunjukkan bahwa sCOD effluen (SCODeff) lindi TPA Piyungan mencapai nilai terendah pada kisaran 2.000 – 2.500 mg/L, Produksi biogas mengikuti fluktuasi nilai sCODeff. Pada kondisi steady state, nilai ini tidak dipengaruhi oleh HRT.

The goal of this study was to assess the effect of different modes of operation and configurations of Anaerobic Sequencing Batch Reactors (ASBRs) treating phenolic wastewater. Several lab-scale reactors were used in the mesophilic range. The reactors were fed with synthetic wastewater with a COD of 5 g/L using phenol as a carbon source (variable concentration) and glucose as a co-substrate. One and two-phase (hydrolytic/acidogenic–methanogenic) systems in batch and fed-batch operation were evaluated. The one-stage reactor operated by the fed batch (which was the only configuration using phenol as a sole carbon source), presented better results for the removal of phenol, reaching 100% removal in 10 days at a concentration of 210 mg/L. The two-stage configuration had removal percentages near 100%, but the methanogenic reactor presented greater degradation of the remaining phenol not removed in the hydrolytic/acidogenic reactor. ASBRs might be a feasible alternative to treat this type of effluent due to their operational flexibility.