Carbon emission and energy potential of a novel spatiotemporally anaerobic/semi-aerobic bioreactor for domestic waste treatment

The biogas generation mechanism and its utilization potential in a novel spatiotemporally anaerobic/semi-aerobic bioreactor (STASAB) system with three activated bioreactors (C1, C2 and C3) was analyzed. Methane generation potential was obtained by measurements and estimation methods with similar values of 23.38 and 27.79 kg CH4/t waste, respectively. CH4 and CO2 production was quickly achieved in the STASAB, and the total amount of CH4 and CO2 was low due to the mixed leachate-recirculation operation process among bioreactors, which were at different stages of operation. The microbial communities in different bioreactors were diverse. The leachate-recirculation operation was a critical parameter to effectively enhance the microbial community structure in the STASAB, which can regulate CH4, CO2 and N2O production with global warming potential of 7.479 kg CO(2)e/(t.d). The STASAB had higher energy potential of 1.011 kWh/(t.d) compared with that of conventional landfills and sequentially anaerobic/semi-aerobic bioreactors. Moreover, direct electricity production in the STASAB is recommended for energy utilization with 38.38% GHG emission reduction, and with 131.43 million CNY (Chinese Yuan) benefit per year for national rural waste disposal via utilization of biogas from the STASAB for power generation. Hence, the STASAB shows a notable potential for treating domestic waste in rural areas. (C) 2020 Elsevier Ltd. All rights reserved.