宝鸡市城镇污水处理厂污泥处置现状分析

Status analysis of sludge disposal of Baoji municipal wastewater treatment plants

目的研究宝鸡市污泥处理处置状况,为其科学处理以避免二次污染以及合理利用提供参考。方法对其近6a的污泥产量及处置状况进行调研,分析4家城镇污水处理厂污泥中Cd,Cr,Cu,Ni,Pb以及Zn 6种重金属元素的总量特征,运用潜在生态危害指数法评价污泥中重金属生态风险,并对宝鸡市污泥处置存在的问题和对策进行简要探讨。结果研究结果表明,填埋仍然是宝鸡市最主要的污泥处置方式。污泥中重金属元素的平均含量从大到小为Zn>Cu>Cr>Ni>Pb>Cd,但其含量均满足《城镇污水处理厂污染物排放标准》(GB18918-2002)要求。重金属污染顺序为Cd>Cu>Pb>Ni>Zn>Cr,污泥Cd和Cu是主要的潜在生态风险元素,在土地利用特别是农用过程中存在一定的生态风险。结论完善污泥处置监督管理制度和费用保障政策,开展污泥资源化综合利用研究,找到适宜污泥处置出路对于保护环境、实现资源综合利用以及可持续发展至关重要。

Purposes—To provide reference for scientific processing,avoidance of secondary pollution and reasonable utilization by studying the treatment and disposal status of sludge in Baoji City,Shaanxi,China.Methods—After investigating the production and disposal status of sludge in the past6 years and analyzing the total amount characteristics of heavy metals（Cd,Pb,Cr,Ni,Zn,and Cu）in different sludge from Baoji municipal wastewater treatment plants,the method of potential ecological risk index was used to evaluate the potential ecological risk of heavy metals in the sludge.Meanwhile,the problem of Baoji＇s sludge disposal and countermeasure were discussed briefly.Results—The results showed that landfill was the major way of sludge disposal.The descending order of heavy metal element content in the sludge was Zn,Cu,Cr,Ni,Pb and Cd,but all the elements met the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant（GB18918-2002）,and the descending order of pollution degree was Cd,Cu,Pb,Ni,Zn and Cr.The results revealed that use of the sludge for land use,especially for the purpose of agriculture,had a certain ecological risk because Cd and Cu were potential risk elements.Conclusion—It is very important for environmental protection,the realization of comprehensive utilization of resources and sustainable development to perfect supervision and administration system of sludge disposal and expense security policy,to research the comprehensive utilizations of sludge from the point of resources and to find the suitable way of sludge disposal.