Development and performance assessment of in-vessel home composters for food waste valorization

Globally, organic food waste (OFW) from residential households forms a major portion of the municipal solid waste. Decentralized composting has emerged as a promising clean-tech solution for OFW management. This study aims to evaluate batch-scale feasibility of in-vessel home composter specifically tailored with compact and modular design for urban households to address issues related to space, odor, and operational challenges. The research methodology was structured in two phases: (a) development of in-vessel composter based on a critical review and on-ground surveys, (b) conduct batch-scale study (45 cycles) to evaluate performance assessment of proposed in-vessel composter under varying operational conditions. It was found that the total organic matter (55 %), pH (8), carbon-to‑nitrogen ratio (12) and germination index (GI) (85 %) of the compost quality was rich in nutrients and soil-conditioning properties. Further, this study also focused on investigating the impact of different bulking agents (dried leaves, cardboard, wheat straw, newspaper, and shredded tires) on the compost quality. It also examined the influence of aeration and turning mechanisms on the composting cycle. Among all the bulking agents tested, wheat straw demonstrated the most effective performance in enhancing compost quality. It showed pH of 7.72, total organic matter of 47 %, GI of 92.8 %, and humic acid to fulvic acid (HA/FA) ratio of 6.57. Compared to other bulking agents, the GI and HA/FA ratio in wheat straw-based compost were 15–20 % higher. In terms of future applicability, the nutrient-rich compost produced from in-vessel composter can be effectively reused as organic manure for community-level gardening, landscaping and soil restoration initiatives.