摘要
为提供合理预防和治理滇池湖滨带重金属污染以及修复湖滨带生态系统的基础资料,应用BCR 3步连续提取法对滇池湖滨带表层沉积物的重金属(包括Pb、Cd、Cu、Zn)形态特征进行了分析,并采用Hakanson潜在生态风险指数法评价其生态危害。结果表明,Cd和Zn主要以可提取态(弱酸溶解态、可还原态、可氧化态)形式存在,其中Cd在弱酸溶解态、可还原态和可氧化态中的质量分数分别为15.89%、26.35%和27.08%;Zn在这3者中的质量分数分别为23.47%、13.36%和20.81%;Pb和Cu则主要以残渣态形式存在,其质量分数分别为62.35%和72.61%。沉积物中可提取态Pb、Cd和Zn含量的空间分布从大到小为草海、外海北部、外海南部,Cu为草海、外海南部、外海北部。潜在生态风险评价结果表明,滇池湖滨带表层底泥已具有很强的生态风险,各重金属对滇池内湖滨带生态风险的影响程度由高到低为Cd、Cu、Pb、Zn。
Speciation and distribution of 4 heavy metals （Pb, Cd, Cu and Zn） in the surface sediments from the lakeside belt of Dianchi Lake were analyzed by using BCR-three step sequential extraction method, proposed by the European Community Bureau of Reference （BCR） . The ecological risk index was presented by Hakanson to assess the potential ecological risk of Dianchi Lake. The aim of this study is to control the heavy metal pollution in Dianchi Lake and to provide the basic information of ecosystem recovery of lakeside belt. The results showed that Cd and Zn were mainly present in three ex- tractable fractions including weak acid soluble fraction, reducible fraction and oxidizable fraction, which were 15.89%, 26.35%, 27.08% for Cd, and 23.47%, 13.36%, 20.81% for Zn, respec- tively. Species of Pb and Cu mainly existed in the residual fraction, which was 62.35% and 72.61% respectively. Compared with Pb and Cu, both Cd and Zn possessed higher mobility which indicated that Cd and Zn showed relatively higher second release potential than the formers. The contents of extractable fractions for 4 heavy metals in the surface sediment were higher in Caohai section than the north and the south of Waihai. Based on the potential ecological risk as- sessment results, the surface sediments from the lakeside belt of Di- anchi Lake had reached high ecological risk level. Particularly, the heavy metal pollution of Daqing river was critical to trigger the attention of the authorities. Briefly, the ecological risk of different metals can be arranged in the order of Cd 〉 Cu 〉 Pb 〉 Zn.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2010年第5期93-97,共5页
Journal of Safety and Environment
基金
国家水体污染控制与治理科技重大专项(2008ZX07101)
国家高技术研究发展计划项目(2005AA60101005)
国家重点基础研究发展计划项目(2008CB418200)
关键词
环境工程学
滇池
湖滨带
重金属形态
生态风险
environmental engineering
Dianchi Lake
lakeside belt
heavy metal
speciation
ecological risk
