Energy composting allows rapid degradation of food waste using a water bath heated with electricity or solar energy

• Published in: Environmental chemistry letters 2021-10, Vol.19 (5), p.3539-3545
• Main Authors: Li, Bing, Shi, Zhihua, He, Minghao, Hu, Tiantian, Dong, Zhiying
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Biodegradation; Cation exchange; Cation exchanging; Cations; Circular economy; Climate change; Composting; Composts; Decomposition; Earth and Environmental Science; Ecotoxicology; Electricity; Energy; Environment; Environmental Chemistry; Exchange capacity; Food waste; Geochemistry; Germination; Heat exchange; Nitrogen; Organic carbon; Organic matter; Original Paper; pH effects; Pollution; Solar energy; Total organic carbon; Water baths
• ISSN: 1610-3653; 1610-3661
• DOI: 10.1007/s10311-021-01250-7

Food waste is a major issue in the context of pollution, climate change, and the future circular economy. Composting kitchen waste is a promising method to recycle elements, yet the efficiency of composting is limited, calling for new processes that degrade rapidly and thoroughly organic matter. Here, we built a rapid laboratory-scale aerobic composting system, equipped with a water bath fueled with either solar energy, or electricity under low sunlight. We tested compositing with and without energy. Results show that only three days are needed to raise the temperature to over 45 °C by energy composting in winter, leading to notable increases in pH, total nitrogen, and cation exchange capacity after 7 days. Composting materials were thoroughly decomposed and mature in 10 days, displaying pH of 7.5, ratio of total organic carbon to total nitrogen of 9.9, cation exchange capacity of 65.61 cmol kg −1 , and germination index of 80.4%. Overall, energy composting starts biodegradation quickly in 2 days, reduces effectively the inhibition from some waste compounds, decomposes organic substances well, and yields mature compost.