Precise Optimization of Poultry Manure Composting Using an Experimental Small-Scale Apparatus

The objective of this study was to determine the precise optimization of poultry manure composting using the same small-scale apparatus, filled with 7 kg of manure that was dried under sunlight and different amounts of sawdust as subsidiary material. In the preliminary experiment, the maximum temperature for the first 7 days of composting reached over 60 degrees Celsius when the moisture content of the mixture decreased below 65%, while the manure-to-sawdust ratio negligibly affected the temperature increase. Under the preliminary conditions, the maximum temperature of poultry manure mixed with sawdust was over 70 degrees Celsius within 2 days after composting and the thermophile phase above 60 degrees Celsius and 55 degrees Celsius continued for an additional 27 and 18 h, respectively. The pH and electrical conductivity of poultry manure composted for 32 days remained at 9.1 and 6.6 mS cm super( -1), respectively, which indicates the manure is safe for land application.