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To achieve successful composting, all the biological, chemical, and physical characteristics need to be considered. The investigation of our study was based on various physicochemical properties, i.e., temperature, ammonia concentration, carbon dioxide concentration, pH, electrical conductivity (EC), carbon/nitrogen (C/N) ratio, organic matter (OM) content, moisture content, bacterial population, and seed germination index (GI), during the composting of poultry manure and sawdust for different aeration rates and reactor shapes. Three cylindrical-shaped and three rectangular-shaped pilot-scale 60-L composting reactors were used in this study, with aeration rates of 0.3 (low), 0.6 (medium), and 0.9 (high) L min −1 kg −1 DM (dry matter). All parameters were monitored over 21 days of composting. Results showed that the low aeration rate (0.3 L min −1 kg −1 DM) corresponded to a higher and longer thermophilic phase than did the high aeration rate (0.9 L min −1 kg −1 DM). Ammonia and carbon dioxide volatilization were directly related to the temperature profile of the substrate, with significant differences between the low and high aeration rates during weeks 2 and 3 of composting but no significant difference observed during week 1. At the end of our study, the final values of pH, EC, moisture content, C/N ratio, and organic matter in all compost reactors were lower than those at the start. The growth rates of mesophilic and thermophilic bacteria were directly correlated with mesophilic and thermophilic conditions of the compost. The final GI of the cylindrical reactor with an airflow rate of 0.3 L min −1 kg −1 DM was 82.3%, whereas the GIs of the other compost reactors were below 80%. In this study, compost of a cylindrical reactor with a low aeration rate (0.3 L min −1 kg −1 DM) was more stable and mature than the other reactors. Implications: The poultry industry is growing in South Korea, but there are problems associated with the management of poultry manure, and composting is one solution that could be valuable for crops and forage if managed properly. For high-quality composting, the aeration rate in different reactor shapes must be considered. The objective of this study was to investigate various physicochemical properties with different aeration rates and rector shapes. Results showed that aeration rate of 0.3 L min −1 kg −1 DM in a cylindrical reactor provides better condition for maturation of compost.

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Purpose This study aimed to achieve successful composting and aeration rate and to optimize the carbon:nitrogen (C:N) ratio to provide favourable conditions for the process. In the current experiment, investigation were made on variations in physico-chemical properties, i.e., temperature, ammonia and carbon dioxide emissions, pH, electrical conductivity (EC), organic matter (OM) and seed germination index (GI%) of composting chicken manure mixed with sawdust and wood shavings under different aeration rates in a closed reactor system. Methods Three cylindrical reactors (total volume, 60 L) were used with three aeration rates of 0.25, 0.50 and 0.75 L min −1 kg −1 OM. The air was dispensed from the bottom of an air compressor. The ambient and compost temperature were monitored thrice daily over 30 days of composting. Results The highest temperatures were 56.9, 55.8 and 48.1 °C, with 0.25, 0.50 and 0.75 L min −1 kg −1 OM aeration rates, respectively. At the end of composting, lowest ammonia and carbon dioxide emissions were observed with 0.25 L min −1 kg −1 OM aeration, indicating that this compost was more stable than other composts. The lowest GI was recorded on day 30 with 0.75 L min −1 kg −1 OM aeration, indicating severe phytotoxicity in the substrate. Maximum OM degradation occurred with 0.25 L min −1 kg −1 OM aeration. Conclusion This study, therefore, suggested that 0.25 L min −1 kg −1 OM aeration in the composing of the chicken manure mixed with sawdust and wood shavings in closed a reactor system provided the most favourable conditions for maturation.