Humification and maturation of kitchen waste during indoor composting by individual households

This study evaluated the humification and maturation of kitchen waste during indoor composting by individual households. In total, 50 households were randomly selected to participate in this study using kitchen waste of their own for indoor composting using a standard 20 L sealed composter. Garden waste was also collected from their local communities and used as the bulking agent. Both effective microorganisms and lime were inoculated at 1% (wet weight) of raw composting materials to facilitate the composting initiation. Results from this study demonstrate for the first time that ordinary residents could correctly follow the instruction to operate indoor composting at household level to manage urban kitchen waste at source. Overall, 30 households provided valid and complete data to show an increase (to ~50 °C) and then decrease in temperature in response to the decline of biodegradable organic substances during indoor composting. The compost physiochemical characteristics varied significantly toward maturation with an increase in seed germination index to above 50% for most households. Furthermore, organic humification occurred continuously during indoor composting as indicated by the enhanced content of humic substances, degree of polymerization, and spectroscopic characteristics.