天津主要水体表层沉积物中重金属污染特征

Pollution Characteristics of Heavy Metals in Surface Sediments in Tianjin

以天津主要水体（于桥水库、团泊洼水库、海河干流、大沽排污河和渤海湾天津近岸海域）为研究对象，测定了表层沉积物中重金属Cd，Zn，Cu，Ni，Pb，Cr，Mn和Fe的含量，采用潜在生态风险指数（RI）、相对富集系数（REF）和相关分析等方法，研究了沉积物中重金属的污染水平、富集规律和可能来源．结果表明：各水体表层沉积物均以Cd和Zn污染较重，Pb，Mn和Cr污染较轻，污染程度为：Cd〉Zn〉Cu〉Ni〉Pb〉Mn〉Cr．Cd和Zn富集相当严重，REF分别在12．68～43．OO和2．48～14．02之间，Mn和Ni的REF均小于4．不同水体的污染程度存在较大差异，大沽排污河、海河干流属于严重污染，具有严重生态风险（RI〉926）；团泊洼水库和于桥水库属于重度污染，具有重度生态风险（RI=508-621）；天津近岸海域属于中度污染，具有中度生态风险（RI=240）．相关分析的结果反映了Cd，Zn，Cr和Pb等重金属来自人类活动的污染，Mn和Ni则以自然来源为主．

Concentrations of cadmium, zinc, copper, nickel, lead, chromium, manganese and iron were analyzed in surface sediment samples from the Yuqiao and Tuanbowa Reservoirs, the Haihe River, the Dagu Sewage Discharge Channel and Bohai Bay in Tianjin, China. Using a potential ecological risk index （RI）, a relative enrichment factor （REF） and correlation analysis, the pollution and accumulation of heavy metals in surface sediments were studied. The results show that Cd and Zn are the major pollutants and Pb, Mn and Cr are minor ones. The pollutants affected by Cif are, in decreasing order, Cd, Zn, Cu, Ni, Pb, Mn and Cr. Cd and Zn are highly enriched. The REF for Cd ranges from 12.68-43.00 and for Zn from 2.48-14.02,while the REFs for Mn and Ni are 〈4. There is a great divergence in the extent of contamination and ecological risk of different water bodies. and the Haihe River are highly contaminated, where the The Dagu Sewage Discharge Channel ecological risk （RI） exceeds 926. The Yuqiao and the Tuanbowa reservoirs are also highly contaminated with an ecological risk ranging from 508 to 621. Bohai Bay is moderately contaminated its ecological risk is 240. A correlation analysis indicated that Cd, Zn, Cr and Pb pollutants are largely the result of anthropogenic activities, while Mn and Ni contamination originates from natural sources.