ABSTRACT
In this paper, startup performance of Upflow Anaerobic Hybrid Reactor and Upflow Anaerobic Sludge Blanket reactors in anaerobic treatment of distillery spentwash has been studied under identical conditions of operation. Various effluent characteristics like pH, Electrical Conductivity, Chemical Oxygen Demand, Biochemical Oxygen Demand and Total Solids and other process parameters like biogas production and methane per cent in biogas were studied until the attainment of steady state. The startup of the reactors has been completed and steady state condition attained on 25[th] day of reactor operation in UAHR and 34[th] day in UASB reactor. The treated effluent characteristics of both reactors were fairly steady after attaining the steady state condition. The pH of treated effluent during steady state condition was almost neutral for both reactors even though the influent had an acidic pH. The maximum COD, BOD and TS removal efficiencies were as high as 79.60%, 87.39% and 69.96% in UAHR as compared with UASB of 72.98%, 81.34% and 66.23%, respectively during the steady state period. The maximum volumetric gas production of 149 L nr3 produced more in UAHR than in UASB reactor during steady state condition. The population of total anaerobic bacteria and methanogenic bacteria also more as that of the other parameters in UAHR than in UASB reactor and it were 55.2 x 10[3] ml[-1] and 40.0 x 10[2] ml[-1] respectively in UAHR. It is found that from an overall assessment the UAHR has proved superior in its performance compared to the UASB reactor during the startup process
Subject(s)
Biofuels , Methane , Hydrogen-Ion Concentration , Electric Conductivity , Biological Oxygen Demand AnalysisABSTRACT
The present study is an attempt to treat the coffee processing wastewater using upflow anaerobic hybrid reactor which offers the advantage of both suspended and attached growth anaerobic reactor systems. Upflow anaerobic hybrid reactor with a volume of 19.5 L was operated at 24 h hydraulic retention time. After the startup period, the reactor was evaluated by operating at different hydraulic retention times of 24, 18, 12 and 6 h. The reactor performed better at HRT=18 h with short period of time. At 18 h retention time, reduction of chemical oxygen demand, biochemical oxygen demand and total solids were 61.0, 66.0 and 58.0 per cent, respectively, with organic loading rate of 9.55 kg/m[3]/day. The maximum quantity of biogas produced were 840, 775 and 430 L/kg of TS, BOD and COD removal, respectively, with the methane content of 60.7% at HRT=18 h. The finding of the study helps to design low cost and compact onsite treatment systems with a very short retention period