TEMPERATURE DISTRIBUTION AND VARIATION IN PASSIVELY AERATED STATIC COMPOST PILES

Temperature distribution and variation in passively aerated static com post piles were investigated in three treatments with initial moisture contents of 73, 76 and 80%. Compost materials consisted of poultry ma nure slurry and peat or chopped straw. Three replicate piles were moni tored simultaneously for each compost treatment. Two open-end perforat ed plastic pipes with 0.1 m diameter were used at the bottom of each p ile for aeration purposes. Temperature in each compost pile was monito red using 23 or 33 thermocouples. Thermophilic temperatures above 45-d egrees-C were attained in the piles within the first 2 days, confirmin g the effectiveness of passive aeration. Temperature distribution resu lts indicate that air diffusion and convection were important passive aeration mechanisms. Cluster analysis of the temperature data suggest that ambient air was drawn into the compost through lower section of t he piles, and warm air moved upwards inducing convection aeration. Tem perature results were highly reproducible in the replicate compost pil es of each treatment. The poultry manure slurry composting process too k on average 30-85 days to complete depending on the amount of manure added and the initial moisture content of the three treatments.