Evaluation of the methane production rate from an acidogenic effluent generated in a two-stage process treating winery wastewater

Abstract

Three methodologies for the calculation of the methane production rate (MPR) were evaluated using an acidogenic effluent of a two-stage process for methane production. A simple method to evaluate the MPR was presented. The MPR was evaluated under different initial substrate concentrations (5, 10, and 15 g L−1), temperatures (35 and 55 °C), and adaptation periods of the thermophilic inoculum. Different patterns of methane were observed for the MPR. The mesophilic sludge degraded the substrate with high initial rates, whereas a thermophilic sludge, acclimated for 226 days, produced the maximal rate after 70 h. This behavior agrees with the different microbial communities observed for each inoculum. The proposed methodology, measuring the instantaneous rates from cumulative methane production, was accurate and straightforward to calculate the MPR independently of the different patterns generated due to the inocula tested.