Pilot-scale SBR and MF operation for the removal of organic and nitrogen compounds from greywater

Abstract

A pilot plant of SBR (Sequencing Batch Reactor) and MF (microfiltration) process was operated in order to treat and reuse the greywater produced from an office building. The performance of SBR for greywater was satisfactory as the effluent had 20 mg/l, 5 mg/l, and 0.5 mg/l of SCOD, BOD, and ammonia, respectively. The cyclic operation of SBR used in this study proved more effective in nitrification and denitrification than the conventional SBR operation. However, the most effective mode was step-feed SBR for denitrification. The decanting system of this SBR discharged the effluent fairly well without sludge washout. However, it was difficult to maintain constant concentration of suspended solid from the SBR process. Thus, additional filtration was needed to get adequate water quality for water reuse. MF could remove residual suspended solids and pathogens as well from the SBR effluent. The suspended solids of final effluent were around 1 mg/l and allowed using the treated water for some purposes.