Performance and Bacterial Communities for Bio-drying with Thermophili Bacteria of Sewage Sludge

This study was conducted to evaluate the effect of the sewage sludge treatment method using bio-drying with Ultra-Thermophilic Aerobic Microorganisms (UTAMs). Twelve specific odorous compounds and various sources of bacteria were tested using the sewage sludge treatment method. Sewage sludge was mixed with a seed material and was composted for 47 days. During composting, the temperature was maintained at 80-90oC. The concentrations of the 12 specific odorous compounds after composting did not exceed the allowable exhaust standard for odor. In terms of the bacterial community number after composting, the thermophile bacterial number was 60% of the total bacterial number. The thermophile bacterial ratio after composting increased by 23% compared to the initial composting. The 16S rRNA gene demonstrated that the change in the bacterial community structure was coupled with shifts in the bio-drying process. Therefore, both stable composting operation and economic benefit can be expected when an ultra-thermophilic composting process is applied to sewage sludge.