FIXED-FILM BIOMETHANATION OF DISTILLERY SPENTWASH USING LOW-COST POROUS-MEDIA

Investigations were conducted using a low cost support media for micro bial attachment and growth for the anaerobic treatment of sugarcane mo lasses based distillery spentwash employing fixed him reactor (FFR) te chnology. An HRT of 3 d corresponding to an OLR of 22 kg COD m(-3)d(-1 ) based on reactor liquid volume (V-L) (V-L=0.534 V-eb, empty bed volu me) with COD reduction of 71.8% and gas yield of 0.45 m(3) kg(-1) COD removed has been achieved in the methane phase. Volatile solids analys is has revealed that about 75% of the biomass is attached to the inert media surface leading to a major contribution in the performance of t he methane reactor. Solids retention time (SRT) of 106 d has been calc ulated at an HRT of 3 d, thereby demonstrating superiority of FFR tech nology over other conventional anaerobic treatment methods. Further, t he waste treatment is affected by the entire media height due to conti nuous effluent recycling. Comparison with granular activated carbon (G AC) has revealed that the media used in the present study has comparab le or even better performance due to larger size of the pores in the m edia.