Environmental Advances (Apr 2023)
Comparative of experimental and theoretical biochemical methane potential generated by municipal solid waste
Abstract
Biochemical methane potential (BMP) test is a common technique for determining the methane generation potential (Lo) of substrates at an anaerobic condition. In this study, Lo of seven components of municipal solid waste, namely cooked food waste (CFW), fruit waste (FW), vegetable waste (VW), uncooked food waste (UCFW), paper waste (PW), garden waste (GW), and textile waste (TW) were assessed in a mesophilic condition for 37 days. Beside that, theoretical Lo was predicted based on the organic composition of substrates, the elemental compositions and chemical oxygen demand (COD) of substrates. In addition to that, the biodegradability index (BDI) was calculated to determine the ratio of experimental BMP to theoretical BMP. The findings from the experimental BMP showed that CFW had a greater methane generation potential, which was 328.39 mlCH4/gVS, than TW with 174.02 mlCH4/gVS of methane generation potential. Among all seven substrates, UCFW had the highest BDI, while the lowest organic fraction identified in the current study wasTW. Theoretical prediction for all substrates reveals the overestimation of methane production compared to the experimental method, with a percentage error in the range of 0.08 %–327.02 %. The theoretical BMP method based on COD composition had correction factors ranging from 0.96 to 2.55, while the theoretical BMP method based on elemental composition had correction factors ranging from 0.50 to 4.27. Two models which were the First-order kinetic model (FOKM) and the ModifiedGompertz model (MGM) were utilised in the current study to evaluate the kinetic behaviours of the measured substrates. The results revealed that the MGM fitted the predicted methane generation potential with the highest R2 value (0.96–0.98) and lowest RMSE (8.71–17.20). Therefore, the baseline data can be used to establish potential solutions in municipal solid waste management systems in Malaysia, as well as to provide guidance to waste-to-energy (WTE) parties.
