Effect of sludge char addition on drying rate and decomposition rate of organic waste during bio-drying

To reduce energy consumption in a sludge drying process, sludge treatment process combined with bio-drying and carbonization was newly developed, which reduced the moisture content of the sludge by less than 30%-wet through bio-drying process without adding any auxiliary fuel. In this experiment, bio-drying of dog food, as simulated organic waste sample, in a lab-scale was carried out and effect of sludge char addition on the drying rate and decomposition rate of wet dog food during bio-drying was analyzed. Addition of sludge char to dog food in bio-drying experiment was found to increase the drying rate and to promote decomposition of organic matter. It was also clarified that the drying rate of dog food and decomposition rate of organic matter increased with increasing amount of char addition. Initial amount of filled dog food also influenced drying rate and decomposition rate; the drying rate and decomposition rate increased with increasing dog food amount.