INFLUENCE ZONE OF AERATION PIPES AND TEMPERATURE-VARIATIONS IN PASSIVELY AERATED COMPOSTING OF MANURE SLURRIES

Natural and passive aeration methods of composting under high initial moisture content condition (76%) were studied. Compost material consis ted of poultry manure slurry as the waste and pear as the bulking agen t. Piles were trapezoidal in section with an initial volume and height of 5 m(3) and 1.2 m, respectively. Correlation factors of temperature readings of identical positions in replicate piles showed that the pr ocess was quite stable and reproducible. Influence zone of passive aer ation pipes was limited to the interior portion of the bottom half of the pile. Temperature distribution inside the piles indicated that pas sive aeration pipes were effective in providing more air than natural aeration. Passive aeration process finished two weeks earlier than nat ural aeration process. The final product had a dark brown color and wa s rich in total nitrogen and phosphorus.