Addressing the gaseous and odour emissions gap in decentralised biowaste community composting

Urban Farm DB summary

A 2024 study that measured methane and nitrous oxide (the main greenhouse gases), ammonia, volatile organic compounds (VOCs) and odour from several operating community composting sites in Spain treating kitchen waste, leftovers and household biowaste. Greenhouse-gas emission rates ranged from 5.3 to 815.2 mg CO₂eq per kg volatile solids per day and odour rates from 69.8 to 1,088.5 odour units on the same basis; both fell as temperature and biological activity declined with composting progress, and both were generally lower than rates reported for open-air full-scale composting plants. VOC families were most diverse in the early composting phases, while terpenes — limonene, α-pinene and β-pinene — were the most abundant throughout. The authors start from the observation that scientific data on gaseous emissions from community composting are scarce, which means that arguments about odour nuisance to neighbours have until now lacked measured reference values.