重庆市场地土壤污染特征分析及行业来源识别

近年来随着大量工业企业关闭或搬离城市地区,中国遗留场地的土壤污染问题日益突出。基于重庆市已开展调查评估的353块工业企业遗留场地数据,分析了重庆市工业场地的环境特征和土壤污染类型;采用相关性分析、主成分分析等多元统计分析方法研究了场地土壤的主要污染因子及其行业来源分布特点。结果表明:82.5%的场地土壤偏碱性,这有利于大部分重金属污染物的稳定;重庆市高风险场地共涉及23个行业,主要有化学原料和化学制品制造业、金属制品业、汽车制造业、铁路、船舶、航空航天和其他运输设备制造业等,这些主要行业的遗留场地土壤出现污染的比例达43%-57%;TPHs和Pb、Cu、Cr、Zn等重金属是重庆市场地土壤主要污染因子,出现污染的概率分别为38%-80%和65%-94%;重金属-TPHs复合污染是重庆市场地土壤的重要污染特征;Pb、Cu、Cr、Zn、Ni、苯、苯并(a)芘、TPHs等典型污染物主要来源于化工、钢铁、电镀、冶炼、运输设备制造业等主要行业。Pb、Cu、Cr、Zn、Ni5种重金属,苯和苯并(a)芘,Pb、Cu、Cr、Zn和TPHs之间呈显著正相关,表明这些污染物可能有着相似的行业来源;Cu、Cr、Zn、Ni主要受金属制品业和运输设备制造业的影响,苯和苯并(a)芘主要受化学原料和化学制品制造业的污染排放影响,而Pb和TPHs的行业来源分布比较广泛。研究结果可为重庆市工业场地的土壤污染防治和风险管控提供科学依据。

Analysis of Soil Pollution Characteristics and Identification of Industry Sources in Contaminated Sites in Chongqing City,China

In recent years,a large number of industrial enterprises are being closed or moved far from urban area in China,and the problem of soil pollution in the industrial sites becomes increasingly prominent.The environmental characteristics and soil pollution types of the industrial sites in Chongqing were analyzed based on the investigation of 353 industrial sites in Chongqing.The main pollutants in the soil of the industrial sites and their source industries were identified by using multivariate statistical analysis methods including correlation analysis and principal component analysis.The results show that the soil in 82.5%sites is alkaline and is conducive to the stability of most heavy metals.Twenty three industries are involved in the sites with high risk in Chongqing,mainly including chemical raw materials and chemical manufacturing,metal products industry,automotive manufacturing,railway,marine,aerospace and other transportation equipment manufacturing,and the pollution frequency of the soil in the sites of these industries is up to 43%–57%;petroleum hydrocarbons and heavy metals including lead,copper,chromium and zinc are the principal pollutants of the sites with high risk in Chongqing,and the pollution frequency of the soil in the sites is as high as 38%–80%and 65%–94%,respectively;heavy metals and petroleum hydrocarbons are the simultaneous pollutants in the most sites with high risk in Chongqing.Typical pollutants including lead,copper,chromium,zinc,nickel,benzene,benzo(a)pyrene,and petroleum hydrocarbons mainly come from industries such as chemical,steel,electroplating,smelting,and transportation equipment manufacturing.There are significant positive correlations among the heavy metals of lead,copper,chromium,zinc and nickel,between benzene and benzo(a)pyrene,between lead,copper,chromium,zinc and petroleum hydrocarbons.Copper,chromium,zinc and nickel are mainly affected by the metal products and transportation equipment manufacturing industries,benzene and benzo(a)pyrene in the soil of the industrial sites are mainly caused by the pollution emissions from chemical raw materials and chemical manufacturing industries,and the soil pollution of lead and petroleum hydrocarbons are from multiple industries.The findings may help the soil pollution prevention and control of the industrial sites in Chongqing.