摘要
从濮阳市9座规模较大且运行稳定的污水处理厂采集城市污泥,对城市污泥的理化性质和重金属浓度、形态分布进行分析,并对其资源化利用的生态风险进行评价。结果表明,城市污泥呈现高有机质、高氮、高磷的特点,且重金属浓度均低于《城镇污水处理厂污染物排放标准》(GB 18918—2002)中的标准限值,具有较高的资源化利用价值。城市污泥中Cu、Pb、Cd、Ni、Cr、As、Hg主要以可氧化态和残渣态存在,在自然环境下较为稳定;Zn主要以酸可交换态和易还原态存在,具有较强的生物活性和迁移性。城市污泥中重金属的潜在生态风险总体较低,Cu、Zn、Cd、Hg为风险元素,其中Zn的污染程度最高,在城市污泥资源化利用时应制定相应防范措施。
Sewage sludge was collected from nine large and stable operation wastewater treatment plants in Puyang. Their physical and chemical properties,heavy metal concentrations and phase speciations were analyzed. Their ecologi- cal risks for resource utlization were also evaluated. The results showed that there were high organic matter,high con- centrations of nitrogen and phosphorus in the sewage sludge. The heavy metal concentrations were all less than the limits in ＂Discharge standard of pollutants for municipal wastcwater treatment plant＂ （GB 18918-2002）. Cu,Pb,Cd, Ni, Cr, As and Hg existed mainly in oxidizable and residual forms, which were stable in natural environment. Zn main- ly existed in acid exchangeable and reduction forms,whose bioavailability and transformation were considerably high. According to the ecological risk assessment, the sewage sludge had slight ecological risks in general. The main risk el- ements were Cu, Zn, Cd and Hg, among which, the pollution level of Zn was strongest. Preventive measures should be formulated in the resource utilization of sewage sludge.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2016年第3期50-55,60,共7页
Environmental Pollution & Control
基金
濮阳市科技攻关计划项目(No.140659)
关键词
城市污泥
重金属
形态分布
生态风险评价
sewage sludge heavy metals
phase speciations ecological risk assessment
