Activated sludge bio-aerobic process to treat sugar industry effluent

Abstract

The sugar industry effluent (SIE) is characterized as high organic load. The aim of this study is to treat SIE by bio-aerobic process in batch and continuous mode in bio-aeration reactor. In batch process, effect of hydraulic retention time (HRT) in terms of effluent fill volume, and in continuous process, effect of HRT in terms of effluent feed rate was studied. In batch process, HRT of 2.5 d (fill volume = 0.8 dm3) was found to be the best and in continuous process, HRT of 1.37 d (feed rate = 133 mL/h) was found to be the best. The chemical oxygen demand (COD) reduction by bio oxidation followed first order kinetics with respect to COD and the rate constant (K) was evaluated as 5.197 d−1. The sludge yield coefficient (a) and sludge endogenous oxidation coefficient (b) were also evaluated from sludge formation studies, which are 0.4 (gm VSS produced/g COD removed) and 0.1 (g VSS oxidized/day. g MLVSS in the aeration basin), respectively. In continuous process, the COD reduction of 83.12% of 4800 mg/dm3 and BOD reduction of 88.70% of 1240 mg/dm3 were obtained at HRT = 1.37 d. The results of the experiments show the SBR process to be an effective process for the treatment of SIE.