Study on the Rate of O₂ Consumption and Purification of Tail Biogas with a Biofilter in the Composting Process

For aerobic static composting, fresh cow, pig, and chicken manures were used as feedstock and mixed with 10 % corn straws, which was considered as the bulking agent. In the composting process of different livestock and poultry manures, the changing trends of temperature, pH, conductivity, density, and other parameters were intensively studied. The results were as follows: (1) after the tail biogases of composting systems - using cattle manure, pig manure, and chicken manure - were introduced into the biofilter, the concentration of O₂ decreased slightly, but the concentration of CO₂ increased. The odour in these tail biogases declined significantly, and thus the biodegradation of tail biogas was obvious. (2) The oxygen consumption in the different periods of the composting process of these three manures was almost the same, and the average oxygen consumption for the three manures was 0.928, 0.937, and 0.945 m³/kg, respectively. Under standard conditions, the density of oxygen is 1.429 g/L, and the average oxygen consumption in the composting processes of these three manures was 1.326, 1.338, and 1.350 kg/kg, respectively.