Biochemical potential evaluation and kinetic modeling of methane production from six agro-industrial wastewaters in mixed culture

Abstract

Methane (CH4) production from anaerobic digestion of solid and liquid agro-industrial wastes is an attractive strategy to meet the growing need for renewable energy sources and promote environmentally appropriate disposal of organic wastes. This work aimed at determining the CH4 production potential of six agro-industrial wastewaters (AWW), evaluating the most promising for methanization purposes. It also aims to provide kinetic parameters and stoichiometric coefficients of CH4 production and define which kinetic models are most suitable for simulating the CH4 production of the evaluated substrates. The AWW studied were swine wastewater (SW), slaughterhouse wastewater (SHW), dairy wastewater (DW), brewery wastewater (BW), fruit processing wastewater (FPW), and residual glycerol (RG) of biodiesel production. RG was the substrate that showed the highest methanization potential. Exponential kinetic models can be efficiently applied for describing CH4 production of more soluble substrates. On the other hand, logistic models were more suitable to predict the CH4 production of more complex substrates.