污泥生物反应器填埋场中PAHs、PCBs含量变化及其影响因素

Variation of PAHs、PCBs contents and influencing factors in sludge landfill

为了解生物反应器填埋场各填埋时期污泥中PAHs、PCBs的含量变化情况,探索影响PAHs、PCBs含量变化的主要因素,为矿化污泥的农用资源化提供科学依据,对生物反应器填埋场填埋400d污泥中PAHs、PCBs含量变化及其影响因素进行了系统研究。研究发现,各填埋时期PAHs的浓度范围为6.645～10.008mg·kg-1,且随填埋时间增加呈现减小的趋势。PAHs化合物主要以4个苯环以上的化合物为主,而小于3个苯环的PAHs化合物含量相对较低。各填埋时期污泥中的PCBs含量随填埋时间增加呈现减小的趋势,浓度范围为15.655～25.569μg·kg-1,远低于国家规定的0.2mg·kg-1的污泥农用标准。填埋初期污泥中PCBs主要以3-Cl和5-Cl化合物为主,填埋后期,2-Cl化合物大大增加,占总的PCBs含量的大部分。影响PAHs、PCBs含量变化的主要因素是生物对PAHs的降解转化。根据污泥中各污染物的含量对污染物进行源解析表明,污泥中PAHs主要来源于炼油厂、炼焦厂、煤气厂、冶炼厂和沥青厂等排放的废水。化工、木材加工、电器等工业污水是污泥中PCBs有机污染物的主要来源。

In order to know about the variation of PAHs and PCBs of sludge in landfill, discover the factors influencing PAHs and PCBs contents, provide the scientific basis for the agriculture reuse of aged-sludge, the variation of PAHs, PCBs contents and influ- encing factors in sludge landfill were studied in this paper. The PAHs concentration of different landfill periods ranged from 6.645 to 10.008 mg·kg-1 and showed an increasing tendency with the increase of landfill time. PAHs were mainly composed of more than four benzene-based compounds, and less than three benzene ring compounds contents of the PAHs were relatively low. The PCBs con- centrations ranged from 15.655 to 25.569 μg·kg-1 and present a decreasing trend with the landfill time, which far less than the stan- dard of 0.2 mg.kg-1. PCBs at the beginning of the landfill were mainly composed of the 3-Cl and 5-Cl compounds. In the late of the landfill, 2-Cl compounds increased significantly. The main factor affecting the PAHs, PCBs contents were microbial degradation and transformation. Analysis of the pollutants sources indicated that PAHs in sludge were mainly derived from the waste water of refinery, coking plant, gasworks, smelt plant and pitch plant. Chemical industry, timber process, electricity industry were the main sources of PCBs in sludge.