Enhancement of biogas generation during co-digestion of tannery solid wastes through optimization of mix proportions of substrates

摘要

Tanneries in India face the twin problems of managing process solid waste and treatment of effluent plant sludge. The present study covered (ⅰ) significance of optimization of mix proportions of substrates i.e., fleshings (F) and the primary sludge (PS) and secondary sludge (SS) generated during treatment of tannery wastewater (ⅱ) residence time during co-digestion for enhancement of biogas generation and (ⅲ) digestate analysis. Maximum biogas generation of 385 mL/g of VS_(added) was observed for the mix proportion of 1.00:2.70:0.30 (F:PS:SS) and a residence time of 45 days during co-digestion of tannery solid wastes. Biogas generation was enhanced by increasing the proportion of PS to SS. After digestion, secondary metabolites i.e., primary, secondary, and tertiary alcohols, amino acids, methane, and ammonia were observed from FT-IR analysis. The exothermic reaction was observed at around 175 ℃ and when C/N ratio of digestate was around 8.0.