Composting of municipal solid waste with microbial-inoculated biochar amendment: impact on process and end-product quality

Abstract This study investigated the application of biochar and microbial-inoculated biochar in municipal solid waste (MSW) composting to enhance and accelerate the process. Microbial consortium from the active composting phase was utilized for inoculation and biofilm formation on the biochar surface. Five experimental windrow piles were established, including a control pile without biochar, and piles amended with either biochar or microbial-inoculated biochar. The composting process and the quality of the final product were evaluated by analyzing a range of physicochemical and biological parameters. The results demonstrated that piles amended with inoculated biochar exhibited higher levels of FDA hydrolytic activity and organic matter reduction, indicating enhanced microbial activity. Notably, piles 3 and 5, amended with biochar inoculated with a bacterial consortium and a bacterial-fungal consortium, respectively, achieved the highest composting temperatures (65 °C) and produced the highest-quality end products (C/N ratio: 10.1–11.8, Germination index: 100, and fecal coliform levels within acceptable limits) compared to the control piles. These findings provide valuable insights into the practical application of microbial-inoculated biochar in the real field of MSW composting, offering a promising approach to optimize composting efficiency and product quality. Graphical Abstract