城市污泥生物好氧发酵对有机污染物的降解及其影响因素

分析了国内部分城市脱水污泥中几种主要有机污染物浓度,PAHs含量为1.156—34.940mg/kg,PCBs含量为0—115.730mg/kg;PCDD/Fs含量为9.530—22.900 ngTEQ/g干泥,NP含量为177.000mg/kg。提出要实现污泥安全、环保的土地利用,可采用生物好氧发酵技术降解污泥中的有机污染物,降低污泥在土地利用时有机污染物带来的环境风险。同时通过优化污泥生物好氧发酵控制条件:C/N值范围为25∶1—40∶1,温度在30—55℃,氧气浓度5%—15%,强制通风量控制在1.5—2.0m3.min-1.t-1(干泥)左右,pH6—9,混料含水率为50%—65%,经生物好氧发酵后的污泥施用土地,可以大大降低污泥在土地利用时的环境风险,避免污泥资源化利用带来的二次污染问题。

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.