Comparison of performance evaluation of sequencing batch reactor (SBR) and sequencing batch biofilm reactor (SBBR) for the treatment of domestic wastewater

The present study is the application of Sequencing Batch Reactor (SBR) and Sequencing Batch Biofilm Reactor (SBBR) for treating the domestic wastewater. The SBBR used in this study contained biomass immobilized in inert support material (polyurethane foam cubes) as well as suspended biomass while in SBR only suspended biomass was used. The SBR was operated for long duration and from day 125 onwards the effluent phosphorus concentration reduced to less than 4 mg/l (80% P uptake). Denitrification was observed from day 120 onwards in the anaerobic phase while nearly complete nitrification was observed in subsequent aerobic phase with effluent ammonia nitrogen concentration less than 2 mg/l. The SBBR took 26 days to reach the steady state condition with treated wastewater Chemical Oxygen Demand (COD), phosphorus, ammonia-nitrogen and nitrate-nitrogen concentrations of 14 mg/l, 3.6 mg/l, 4.5 mg/l and 6.1 mg/l respectively. The SBBR was operated for 106 days and during the study nearly complete COD removal was observed and the effluent phosphorus concentration was in the range of 2.7 to 3.6 mg/l, ammonia-nitrogen concentration was less than 1 mg/l and denitrification was nearly 100% at the end of anaerobic phase. From this study it was found that SBBR was more effective in removing nitrate-nitrogen when compared to SBR.