Performance of anaerobic baffled reactor for domestic wastewater acidification under low temperature

The effect of low temperature on the performance of anaerobic baffled reactor (ABR) with four compartments for domestic wastewater acidification was investigated. Under the conditions of hydraulic retention time (HRT) 3 hours, influent chemical oxygen demand (COD) 230-300 mg/L, total phosphorous (TP) 1.59-1.93 mg/L, ammonia nitrogen (NH4-N) 23 -28 mg/L, influent temperature 8-15 degrees C, effluent temperature 3-9 degrees C, the reactor got maximum 56% o soluble COD removal. Net COD removal amount in the first two compartments made up of 64% of total COD removal amount, the rest was completed in the other two rooms. COD removals had the same feature as net COD removal amount variation. The volatile suspended solid (VSS) concentrations were different in different compartments, the first two rooms had higher VSS concentrations. COD removal difference was caused by different biomass in the compartments higher biomass corresponded to higher COD removal. Along flow direction, acidification bacteria INT dehydrogenase activity (DHA) in different compartments tended to decrease. The experimental results show that different nutrients levels produce different microorganisms INT-DHA, higher nutrients concentrations correspond to higher microorganism INT-DHA and higher COD removal.