EFFECT OF ADDITION OF SULFATE, SULFATE REDUCING BACTERIA AND CELLULOLYTIC CULTURES ON BIOGAS FORMATION FROM CABBAGE WASTE

Effect of addition of sulfate, sulfate reducing bacteria and mixture of cellulolytic culture on biogas formed and its methane and hydrogen sulfide contents was studied in laboratory digestors fed with acid-treated cabbage waste. Addition of 1-2 mM SO4- and cellulolytic cultures enhanced methanogenesis, where as at higher levels of SO4- the CH4 content was reduced with a concomitant increase in H2S. Incorporation of sulfate reducing bacteria alone or with cellulolytic cultures was not beneficial. With optimal combination of 1mMSO4- and cellulolytic cultures, maximum gas yield of 2.75 L/day/kg DW containing 75% CH4 and 1.36 ppm H-2 S was obtained. SO4- Concentration of the digester mix effect biogas production.