Degradation of organic contaminants with biological aerobic fermentation in sewage sludge dewatering and its influencing factors

Concentrations of the organic contaminants in sewage sludge dewatering of several Chinese cities were analyzed,and pointed out the concentration of PAHs was 1.156—34.940mg/kg,PCBs content was 0—115.730mg/kg;PCDD/Fs concentration was 9.530—22.900ngTEQ · g-1dm,NP concentration was 177 mg/kg.This paper demonstrated that the organic contaminants in sludge can be degraded with the aerobic biological treatment technology,and the environment risk of the organic contaminants in sewage sludge can be reduced to realize the safety and environmental protection of land use.Meanwhile,by optimizing sludge biological aerobic fermentation control conditions: C/N in the range of 25 ∶ 1 to 40 ∶ 1,a temperature of 30 to 55℃,the oxygen concentration is 5%—15%,forced ventilation control in 1.5—2.0m3 · min-1 · t-1(dried mud),pH6—9,mixing water rate is 50%—65%,the environmental risk of sewage sludge land application can significantly be reduced.The resource utilization of the sludge to bring about two pollution problems can also be avoided.