江西陡水水库水环境重金属时空分布特征及生态风险评价

Profiles of heavy metals pollution and potential influence to aquatic environment of Doushui Reservoir from Jiangxi Province

本研究采用电感耦合等离子体质谱仪(ICP-MS)分析江西陡水水库表层水体及沉积物中Cu、Zn、As、Hg、Pb和Cd的含量水平,利用内梅罗综合污染指数评价法、地累积指数评价法、潜在生态风险指数法等方法对污染程度和生态风险进行评价.结果表明,陡水水库表层水体中Cu、Zn、As、Hg、Pb和Cd的浓度范围分别为0.10—9.24、nd—96.48、0.06—16.8、nd—0.64、nd—8.46、0.004—0.37μg·L^(−1).陡水水库沉积物中Cu、Zn、As、Hg、Pb和Cd的含量水平分别为(190.59±45.95)、(426.70±144.65)、(201.43±175.79)、(26.49±23.23)、(103.75±30.88)、(6.38±5.42)mg·kg^(−1),其中Cu、Zn、As和Pb的最高浓度分别达到了江西省赣州市土壤背景值的11.82、9.13、53.87、2.94倍.综合污染指数评价法表明,陡水水库表层水体受到重金属污染,其中DS5为重度污染,DS3和DS4为轻度污染,主要污染物质为Hg;地累积指数评价法表明,陡水水库沉积物中As污染较重,其次为Cu和Zn;潜在生态风险指数法表明,DS3和DS5重金属具有很强生态危害,As为主要贡献因子;生物毒性不利影响评价表明,DS3和DS5重金属发生生物毒性影响的可能性为75%—81%.因此,在陡水水库重金属治理中要加强对Hg和As的防控.

Inductively coupled plasma mass spectrometry(ICP-MS)was used to qualify and quantify six commonly monitored heavy metals,Cu,Zn,As,Hg,Pb and Cd,in surface waters and sediments,at Doushui Reservoir from Jiangxi Province,China.Contamination degree and ecological risk of the heavy metals to aquatic ecosystem was further evaluated by comprehensive environmental pollution index(CEPI),geo-accumulation index(Igeo),potential ecological risk index(ERI)and so on.The results showed that concentrations of Cu,Zn,As,Hg,Pb and Cb in the surface waters ranged at 0.10—9.24,not detected(nd)—96.48,0.06—16.8,nd—0.64,nd—8.46 and 0.004—0.37μg·L^(−1),respectively.Concentrations(mean±standard deviation)of Cu,Zn,As,Hg,Pb and Cd in the sediments were at(190.59±45.95),(426.70±144.65),(201.43±175.79),(26.49±23.23),(103.75±30.88)and(6.38±5.42)mg·kg^(−1),respectively.The maximum concentrations of Cu,Zn,As and Pb in the sediments were 11.82,9.13,53.87 and 2.94 times,respectively,of the soil background values of those metals in Ganzhou City,Jiangxi Province.CEPI evaluation indicated that the surface water at DS5 was the most heavily polluted site especially by Hg whereas results from Igeo demonstrated that the sediments were mainly polluted by As,followed by Cu and Zn.The ERI assessemnt indicated that sites of DS3 and DS5 suffered a higher risk driven by the heavy metals with As as the main contributor.The adverse biological effects(ABE)data pointed out that the probability of toxic effects posed by the heavy metals ranged from 75%to 81%at the sites of DS3 and DS5.Therefore,aquatic contaminations of Hg and As in Doushui Reservoir deserved more attention for their further control and regulation.