실험실 규모 하수슬러지 퇴비화공정에서 기계적 교반이 배출가스 내 부유세균과 내독소의 발생특성에 미치는 영향

This study was performed to investigate the concentration variation of airborne bacteria and endotoxin by the temperature in the compost pile in order to identify the generation characteristics of biological factors in the exhaust gases generated from labscale sludge compositing reactors (0.06 m3 of total reactor volume). Airborne bacteria showed the highest concentration of generation (1.03 × 105 CFU/m3) in the composting reactor without mechanical agitation, and similar change tendency to temperature variation of composting, but somewhat lower statistical significance (p > 0.05). In the compost reactor with mechanical agitation, endotoxin showed similar generation characteristic to temperature variation of composting (statistical significance; p < 0.05) and the highest generation concentration to 1,415 EU/m3. Mechanical agitation of the composting process affected activity of microorganism and positive generation of endotoxin in exhaust gases. Endotoxin and airborne bacteria showed similar tendency of generation, especially the highest statistical correlation was observed in the compost reactor without mechanical agitation (statistical significance; p < 0.01).