梁子湖沉积物重金属污染现状分析及风险评价  

Pollution analysis and ecological risk assessment of heavy metals in sediments of Liangzi Lake

作　　者：王丹[1,2] 孟鑫[3] 张洪[2] 高泽晋[2] 单保庆[2] 李思敏[1] 

机构地区：[1]河北工程大学城市建设学院,邯郸056038 [2]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085 [3]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《环境科学学报》2016年第6期1901-1909,共9页Acta Scientiae Circumstantiae

基　　金：国家水体污染控制与治理科技重大专项(No.2012ZX07101-002)~~

摘　　要：采集了梁子湖柱状沉积物,分析了Cd、Sn、As、Cu、V、Zn、Ni、Cr、Co、TI、Pb和Mo 12种重金属元素的含量及空间分布,并对其污染源进行解析,最后对重金属的生态风险作出评价.结果表明,在空间分布上,东部湖区存在严重的重金属污染问题,其中,Cd的平均含量达到0.80 mg·kg^(-1),是湖北省土壤背景值的4.66倍;Sn和As平均含量分别为6.35 mg·kg^(-1)和35 mg·kg^(-1),已经超过湖北省土壤背景值近2倍;在垂直分布上,Cd和Zn在0~20 cm深度上富集现象明显,平均含量分别为0.67 mg·kg^(-1)和116 mg·kg^(-1).富集系数EF值表明,Cd、Sn、As主要来自人为污染.单一重金属潜在生态风险指数Eri值范围在3~140之间,以Cd污染最严重,Eri平均值为140,表现为较重生态风险,其他11种元素均为低等生态风险水平.综合生态风险指数RI值显示,梁子湖整体处于中度污染水平,其中,东部湖区风险程度最大.梁子湖作为武汉市备用水源地,沉积物重金属Cd、Sn、As含量过高将威胁湖水质量,危及水生态安全和人体健康.The spatial distribution and potential ecological risk of sedimentary heavy metals（ Cd、Sn、As、Cu、V、Zn、Ni、Cr、Co、TI、Pb、Mo） in Liangzi Lake,were analyzed using enrichment factor（ EF） and Hkanson potential ecological risk index. The results show that the heavy metal pollution was more serious in the east lake. The content of Cd（ 0.80 mg·kg^-1）,compared to the background values of soil in the Hubei Province,exceeded 4.66 times. The content of Sn and As（ 6.35 mg·kg^-1） and 35 mg·kg^-1 respectively）,exceeded 2.88 and 2.65 times of the standard values. On the vertical distribution,the accumulations of Cd and Zn were observed in the surface sediments（ 0 - 20 cm） and the content were 0. 67 mg·kg^-1 and 116 mg·kg^-1 respectively.Enrichment coefficient show that Cd,Sn,As contents were seriously influenced by anthropogenic sources and others mainly were affected by natural causes. The most serious Cd pollution reached the higher level of risk（ average of Er^i was 140）,and pollution of the other heavy metals were low.Potential ecological risk index shows that east lake was polluted most seriously. Liangzi Lake,as a backup water source for Wuhan City,bears a major responsibility for supplying drinking water in an emergency. Higher sediment content of heavy metal of Cd,Sn,will threaten the water quality and endanger the water ecological security and human health.

关 键 词：梁子湖 沉积物 重金属 空间分布 风险评价 

分 类 号：X522[环境科学与工程—环境工程]