贵州草海菜地表层土壤重金属污染特征及生态风险评价  

Characteristics of Heavy Metals Pollution and Ecological Risk Assessment of the Surface Soils in the Vegetable Fields around Caohai in Guizhou

作　　者：赵斌 朱四喜[1,2] 杨秀琴 吴云杰[1,2] 汤茜 顾金峰[1,2] ZHAO Bin;ZHU Sixi;YANG Xiuqin;WU Yunjie;TANG Qian;GU Jinfeng(Institute of Karst Wetland Ecology,Guizhou Minzu University,Guiyang 550025,China;College of Eco-environment Engineering,Guizhou Minzu University,Guiyang 550025,China)

机构地区：[1]贵州民族大学喀斯特湿地生态研究中心,贵州贵阳550025 [2]贵州民族大学生态环境工程学院,贵州贵阳550025

出　　处：《生态环境学报》2018年第4期776-784,共9页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31560107);贵州省研究生科研基金项目(KYJJ2017006)

摘　　要：贵州草海是典型的高原湿地生态系统,评价其周边菜地重金属污染特征及生态风险,对于草海蔬菜食用安全及其生产地土壤污染综合防治和湿地土地资源保护具有重要意义。在草海周边采集8个具有代表性的菜地表层土壤,测定Zn、Cu、Cr、Pb、Ni和As含量,分析其分布特征、来源和生态风险。结果表明,草海菜地表层土壤重金属含量表现为Zn(159.06mg·kg^(-1))>Cr(92.11mg·kg^(-1))>Pb(63.72mg·kg^(-1))>Ni(45.74mg·kg^(-1))>Cu(27.75mg·kg^(-1))>As(24.58mg·kg^(-1))。其中,Zn、As、Pb和Ni含量较贵州省土壤重金属含量背景值高,Cu、Cr则低于背景值,而6种重金属含量均低于《土壤环境质量标准》(GB15618—1995)Ⅱ级标准值。Zn、Cr、Ni属于中等变异,服从正态分布;Cu属于中等变异,As、Pb属于高度变异,服从偏正态分布。Zn与Cu相关性极显著(P<0.01)、Cu与Pb,Ni与As,Cr与Pb、Ni间相关性显著(P<0.05)。土壤环境质量评价表明,Cu、Cr、Ni和As为轻污染,Zn、Pb为中等污染。然而,生态风险评价表明,6种重金属的危害指数(RI)值为23.92,小于轻微的生态危害下限(RI=150),故草海菜地土壤存在轻微的生态危害。来源解析表明,因子1(F1)包含Zn、As,因子2(F2)包含Cr、Pb,因子3(F3)包含Cu。其中,因子1(F1)、因子2(F2)为外源因子,代表农业、工业、矿产和生活垃圾等;因子3(F3)为自然因子,代表土壤母质的形成。因此,草海周边菜地表层土壤Zn、As、Cr、Pb、Ni的来源可能与农业、工业、矿业和生活垃圾等有关,Cu来源可能与土壤母质有关。Caohai is a typical highland wetland ecosystem in Guizhou province.It is of great significance to evaluate the characteristics of heavy metals pollution and ecological risk of surface soils in the vegetable fields around Caohai,which will be helpful for protecting the land resource and the vegetable food safety and for soil pollution control of the production area.8 representative vegetable field surface soils were collected around Caohai to determinate the concentrations of Zn,Cu,Cr,Pb,Ni and As,and their distribution characteristics and sources were analyzed and ecological risk were assessed.The results showed that the concentrations of heavy metals in the vegetable field surface soils around Caohai were Zn(159.06 mg?kg-1)>Cr(92.11 mg?kg-1)>Pb(63.72mg?kg-1)>Ni(45.74 mg?kg-1)>Cu(27.75 mg?kg-1)>As(24.58 mg?kg-1).Among them,the concentrations of Zn,As,Pb and Ni were higher than the background values of soil heavy metals in Guizhou province,and the concentrations of Cu and Cr were lower than the background values.However,the concentrations of 6 kinds of the heavy metals were all lower than the values of the ClassⅡStandard of the Soil Environment Quality Standards(GB15618-1995).The variation degree of Zn,Cr and Ni belonged to medium,their concentrations obeyed the normal distribution.And the variation degree of Cu belonged to medium,As and Pb belonged to height,and their concentrations obeyed the skewed positive distribution.The correlation between Zn and Cu was very significant(P<0.01),and Cu and Pb,Ni and As,Cr with Pb and Ni wassignificant(P<0.05),respectively.The soil environmental quality assessment indicated that Cu,Cr,Ni and As belonged to light pollution,Zn and Pb were medium pollution.As for the ecological risk assessment,the risk index(RI)value of 6 kinds of heavy metals was 23.92,which was lower than the lowest value of RI(RI=150),and indicated the degree belonged to slight.The source analysis showed that factor 1(F1)contained Zn and As,factor 2(F2)contained Cr and Pb,and factor 3(F3)contained Cu.And F1

关 键 词：重金属 草海 菜地土壤 生态风险评价 土壤环境质量 

分 类 号：X833[环境科学与工程—环境工程]