北京城市污水处理厂污泥中重金属污染状况及潜在生态风险分析  

Pollution feature and assessment of potential ecological risk of heavy metals in municipal sludge from wastewater treatment plants in Beijing

作　　者：杨妍妍[1] 李金香[1] 刘亚平 方永晨 崔彤[1] 刘兆莹[1] 程刚[1] YANG Yanyan;LI Jinxiang;LIU Yaping;FANG Yongchen;CUI Tong;LIU Zhaoying;CHENG Gang(Beijing Municipal Environmental Monitoring Center,Beijing 100048;College of Resource Environment and Tourism,Capital Normal University,Beijing 100048)

机构地区：[1]北京市环境保护监测中心,北京100048 [2]首都师范大学资源环境与旅游学院,北京100048

出　　处：《环境污染与防治》2019年第9期1098-1102,1107,共6页Environmental Pollution & Control

摘　　要：2011-2017年对北京城市中心区8家污水处理厂污泥中8种重金属(Cd、Cr、Cu、Zn、Pb、As、Hg、Ni)开展了持续监测,分析其重金属污染状况、年际及季节变化特征,并应用内梅罗指数法评估污泥在土地利用过程中重金属的潜在生态风险。结果表明:污泥重金属含量为Zn>Cu>Cr>Pb>As>Ni>Hg>Cd,除Hg外,其他重金属含量均低于全国平均水平;四季重金属总量中位值较接近,夏季稍高;Ni、Cd、Hg各年年均值变异系数最大,分别为43%、36%、23%,其他金属变异系数为5%~13%;56%的Hg检测结果超过了《城镇污水处理厂污泥处置农用泥质》(CJ/T 309-2009)中A级污泥限值,且8家污水处理厂均有超标记录;内梅罗指数显示Hg、Zn、Cd、Cu达到重度污染级别,污泥施用于土壤存在较严重的潜在生态风险。因此,污泥用于土壤环境前,需降低其重金属含量。From 2011 to 2017,sludge samples were collected from 8 wastewater treatment plants in Beijing urban central area,and 8 heavy metals(Cd,Cr,Cu,Zn,Pb,As,Hg and Ni)in sewage sludge were tested.The characteristics,the interannual and seasonal changes of the metal pollutants were analyzed,and the potential risk for the soil was assessed by Nemerow pollution index.The results showed that the distribution characteristics of heavy metals in sewage sludge were Zn>Cu>Cr>Pb>As>Ni>Hg>Cd.Except for Hg,other 7 heavy metals were lower than the average level of urban sludge in the whole country.The median values of total heavy metals were close among seasons and slightly higher in summer.Variation coefficient of Ni,Cd,Hg annuale average were the largest,with 43%,36%and 23%,respectively;other metals were from 5%to 13%.About 56%of the test results of Hg were exceeding Class A sludge limit of“Disposal of sludge from municipal wastewater treatment plant-control standard for agricultural use”(CJ/T 309-2009),and all of the 8 wastewater treatment plants had records that exceeded the limit.Results of Nemerow pollution index revealed that Hg,Zn,Cd,Cu had severe potential ecological risk for sludge land applications.This observation suggested heavy metals would cause serious ecological risk when sludge was directly utilized as fertilizer.So the sewage should reduce the heavy metals before using for agriculture.

关 键 词：污水处理厂 污泥 重金属 特征分析 潜在生态风险分析 

分 类 号：X70[环境科学与工程—环境工程]