Emission of carbon monoxide during composting of dung and green waste

Emissions of CO were observed during composting of green waste from landscape care, during windrow composting of livestock waste, and on a laboratory scale, during biodegradation of biomass in a temperature and ventilation controlled substrate container. An FT-IR spectrometer was utilised for gas analysis. The maximum concentrations of CO were about 120 ppm in compost piles of green waste, about 10 ppm during composting of livestock waste, and about 160 ppm during laboratory experiments. The total flux ratio of CO-C to CO2-C was for composting of green waste 5 10(-4). For windrow composting, the ratio of CO-C to CO2-C was 4.7 10(-4) and the mean total flux of CO was 2.8 g m(-2). By laboratory studies, the ratio between CO-C and CO2-C was in the range between 2.9 10(-5) and 2.7 10(-4). The emission of CO depends on temperature. Physical-chemical processes in connection with microbial activities are assumed to be the source for the temperature-time dependence of the CO-emissions.