Anaerobic Co-digestion of Food Waste for Biohydrogen Production

The objective of this study was to find the optimum conditions for anaerobic co-digestion of food waste and sewage sludge and hydrogen (H2) production. The selected parameters for optimization of H2 production (e.g. temperature, initial pH, inoculum size) were analysed using Response Surface Methodology with Full Factorial Design. Two types of substrates were tested; food waste as a sole substrate and food waste mixed with palm oil mill effluent (POME) at volume ratio 1:1. The optimized conditions for food waste as a sole substrate were pH 4.5, temperature of 35°C and inoculum size of 20% (v/v), with maximum predicted cumulative hydrogen production (MPCHP) of 0.22 ml H2/ml substrate. On the other hand, for food waste mixed with POME, pH 4.5, temperature of 35°C and inoculum size of 20% were the optimum conditions with MPCHP of 0.26 ml H2/ml substrate. Subsequently, verification experiments at optimal parameter values yielded cumulative H2 of 0.28 ml H2/ml substrate for food waste only, and 0.33 ml H2/ml substrate for food waste mixed with POME.