巢湖流域市政污泥重金属形态分布及生态毒性研究  

Speciation Distribution and Ecological Toxicity of Heavy Metals in Sewage Sludge from Chaohu Lake Basin

作　　者：杨长明[1] 荆亚超 王育来[2] 张敏[1] 韩登程 

机构地区：[1]同济大学环境科学与工程学院,上海200092 [2]安徽工业大学能源与环境学院,安徽马鞍山243002

出　　处：《中国给水排水》2017年第3期82-86,92,共6页China Water & Wastewater

基　　金：国家水体污染控制与治理科技重大专项(2014ZX07303-003;2011ZX07303-004)

摘　　要：采用Tessier逐步提取法研究了巢湖流域13座典型城镇污水厂剩余污泥中重金属形态分布特征,并结合小麦发芽试验对污泥样品的生态毒性进行了分析。结果表明,污泥样品中Pb、Cu、Cr、As、Cd、Ni、Zn的质量分数分别为16.27~55.56、50.29~310.60、56.14~1 205.32、3.72~33.65、0.81~2.19、10.61~201.38、227.99~3 089.20 mg/kg,不同污水处理厂污泥中重金属含量差别较大。形态分级结果表明,污泥样品中Pb主要以残渣态形式存在,其生物有效性较小;Cu、Cr、As主要以有机结合态和残渣态形式存在,其生物有效性和释放潜力都较弱;而Cd、Ni主要以铁锰氧化物结合态、有机结合态和残渣态形式存在,具有一定的迁移能力和潜在的生态危害;Zn具有相对较大释放潜力和生物有效性。综合毒性试验表明,大部分污泥样品的浸提液对小麦发芽具有一定程度的抑制作用,且发芽指数与可交换态重金属含量呈极显著负相关(P<0.01)。以上结果表明,尽管巢湖流域大部分污水处理厂污泥能够满足园林绿化用泥质标准,但是在施用前需对污泥重金属进行稳定化处理,以降低土地利用的生态风险。The speciation distribution of heavy metals in excess sludge samples collected from thirteen typical municipal wastewater treatment plants in Chaohu Lake basin was studied by using Tessier sequential extraction, and the ecological toxicity of the samples was analyzed combined with wheat seed germination experiment. The results showed that the content of the same kind of heavy metal in sludge samples from different wastewater treatment plants varied obviously. The mass fractions of Pb, Cu, Cr, As, Cd, Ni and Zn ranged from 16.27 to 55.56 mg/kg, 50.29 to 310.60 mg/kg, 56.14 to 1 205.32 mg/ kg, 3.72 to 33.65 mg/kg, 0. 81 to 2.19 mg/kg, 10.61 to 201.38 mg/kg and 227.99 to 3 089.20 mg/ kg, respectively. Pb existed mainly in residual fraction, and its bioavailability was very low. Cu, Cr and As were dominantly associated with residual and organic fraction, and their bioavailability and release potential were relatively weak. Cd and Ni were principally distributed in the Fe-Mn oxides, organic and residual fraction and showed a certain migration ability and potential ecological risk. Zn had relatively high bioavailability and release potential. Ecological toxicity analysis showed that the extracts from most of the sludge samples had significant inhibition effects on wheat seed germination, and germination index was significantly （P 〈 0. 01 ） negatively correlated to exchangeable heavy metal fraction. The above results indicated that although most of sewage sludge samples from Chaohu Lake basin could meet the quality standards for green land use, heavy metals should be stabilized before applied for land use to reduce the ecological risk.

关 键 词：巢湖流域 市政污泥 重金属 Tessier逐步提取法 生态毒性 

分 类 号：X171.5[环境科学与工程—环境科学] X703