厦门集美杏林湾水库底泥重金属污染状况评价

Evaluation of Heavy Metal Pollution Status of Sediment in Xinglin Bay Reservoir Jimei Xiamen

为了研究厦门市集美区杏林湾水库底泥重金属污染状况,利用相关性分析、地积累指数法、潜在生态风险指数法和污染负荷指数法,对杏林湾水库底泥中重金属污染特征和生态风险进行评价。结果表明:底泥中Zn,Cu,Ni,Cr,Pb,Cd,Hg,As质量比平均值分别为270.00,76.94,38.88,88.38,48.13,0.41,0.07,3.85 mg·kg^(-1),除了As和Pb质量比平均值低于背景值外,Cd,Cu,Zn,Ni,Cr,Hg质量比平均值分别达到背景值的13.67,6.52,4.61,2.99,3.03,2.33倍;Zn,Cu和Cr变异系数均大于50%,尤其是Cu和Cr,变异系数均超过100%,其空间分布不均匀,受人为因素影响较大;Zn和Cu的质量比空间分布呈现沿水流方向逐渐减小的特征,Ni和Cr的质量比空间分布呈现从后溪汇入处至入海口处逐渐增加,从九天湖排洪渠和董任排洪渠交汇处至入海口处逐渐减小的特征,Pb,Hg,As的质量比空间分布较为均匀,Cd的质量比空间分布随着水流方向起伏较大;底泥中重金属污染主要来自周边人类活动排放和上游支流汇入;除Pb,As为无污染状态外,Zn,Cu,Ni,Cr,Cd和Hg均呈现不同程度的污染,且Cd的污染程度最高;杏林湾水库底泥重金属潜在生态风险整体处于强至很强之间。

In order to study the pollution status of heavy metals in the sediment of Xinglin Bay Reservoir Jimei District,Xiamen City,the methods of the correlation analysis,geo accumulation index,potential ecological risk index and pollution load index are used to evaluate the characteristics and ecological risk of heavy metals pollution in the sediment of Xinglin Bay Reservoir.The results show that the average values of the mass ratios of Zn,Cu,Ni,Cr,Pb,Cd,Hg and As in the sediment are 270.00,76.94,38.88,88.38,48.13,0.41,0.07,3.85 mg·kg^(-1),respectively,except average mass ratios of As and Pb less than the background values,the average mass ratios of Cd,Cu,Zn,Ni,Cr and Hg are 13.67,6.52,4.61,2.99,3.03 and 2.33 times greater than the background values of respectively.The variation coefficients of Zn,Cu and Cr are all greater than 50%,especially the variation coefficients of Cu and Cr are all greater than 100%,their spatial distribution are not uniform and highly influenced by human factors.The spatial distribution of the mass ratios of Zn and Cu show a gradual decrease characteristics along the direction of water flow,the spatial distribution of the mass ratios of Ni and Cr show a gradual increase characteristics from the confluence of Hou River to the estuary,and a gradual decrease characteristics from the confluence of Jiutian Lake and DongRen Drainage Canals to the estuary,the spatial distribution of the mass ratios of Pb,Hg and As are relatively uniform,and the spatial distribution of the mass ratio of Cd has a great fluctuation with the direction of water flow.The heavy metals pollution in the sediment is mainly from discharges from neighboring human activities and inflows from upstream tributaries.Except non pollution state of Pb and As,Zn,Cu,Ni,Cr,Cd and Hg are all polluted to different degrees,and Cd has the highest degree of pollution.The potential ecological risk of heavy metals in the sediment of Xinglin Bay Reservoir is generally between strong and very strong.