Anaerobic hybrid reactor: a promising technology for treatment of distillery spent wash

A laboratory-scale study was conducted to investigate the performance of anaerobic hybrid (combining sludge blanket and filter) and UASB (Upflow Anaerobic Sludge Blanket) reactors for the treatment of distillery spent wash. The start-up and granulation study demonstrated that early start-up and granulation were achieved in case of hybrid reactor (45 days) as compared with UASB reactor (60 days). The investigation of the effect of Hydraulic Retention Time (HRT) on the performance of reactors indicated that at optimum HRT (5 days) and Organic Loading Rate (OLR) 8.7 kg COD/m³/d, the COD removal in hybrid and UASB reactors was found to be 79% and 74.5%, respectively. The rate of sludge washout was reduced by 25% in hybrid reactor as compared with the UASB reactor. The study on the shock loading capacity of the reactors revealed that hybrid reactor is capable of resisting organic shock load up to two times as compared to the UASB reactor capable of resisting the shock loading up to 1.5 times of normal organic load.