为探讨成都市部分区域淡水混养池塘环境中重金属的生态风险和分配特征,对成都市10个淡水混养池塘水体和沉积物中Cu、Zn、Cd、Pb、Cr、Ni这6种重金属进行检测,采用BCR连续提取法分析沉积物中6种重金属的赋存形态,并评价其潜在生态风险.结果表明,除S8和S10样点Zn年均浓度超出GB 11607—1989《渔业水质标准》外,其余元素均未超标,重金属浓度总体呈现出春、夏季高于秋、冬季的特征.沉积物除S3、S4和S8样点Cu年均含量超出生物低影响阈值(ERL)外,其余元素均未超标,Cd为研究区域沉积物中主要生态风险因子,沉积物中重金属无明显季节变化规律.沉积物中Cd的弱酸提取态比例高于其余元素,为22.91％～64.51％,Pb和Cu可还原态比例较大,Zn以残渣态为主,同时存在较大比例的弱酸提取态和还原态,Cr和Ni主要以残渣态和可氧化态存在.水体-沉积物中重金属分配系数由高到低依次为Ni、Pb、Cr、Cu、Cd和Zn.因此,应加强成都市淡水混养池塘Cd元素的污染防控.%In order to survey the partition characteristics and potential ecological risks of heavy metals in environment of freshwater polyculture ponds in partial areas of Chengdu City, the concentration of six heavy metals (Cu, Zn, Cd, Pb, Cr, Ni) in water and sediments of 10 sampling sites were detected. BCR sequential extraction method was used to analyze the speciation of six heavy metals, and the potential risks of heavy metals were evaluated. The results show that, the annual average concentration of heavy metals in water were up to the Fishery Water Quality Standards, except the concentration of Zn in S8 and S10 sites. The heavy metal concentrations in spring and summer seasons were higher than those in autumn and winter seasons. The annual average concentration of heavy metals in sediments were up to the ERL (effects range-low) standards, except the concentration of Cu in S3、S4 and S8 sites. The Cd in sediments had the highest potential risk. There was no obvious seasonal variation in heavy metal concentrations in sediments. The ratio of weak acid extractable fraction of Cd (22. 91％-64. 51％) was the highest among all the heavy metals. The reducible fraction of Pb and Cu occupied a large proportion. Zn mainly dominated in residual fraction, with a larger proportion of weak acid extractable fraction and reducible fraction. Cr and Ni were dominated in residual and oxidizable fraction. The order of partition coefficient of heavy metals in water-sediments was Ni＞ Pb＞ Cr＞ Cu＞ Cd＞ Zn. Therefore, the pollution control of Cd in freshwater polyculture ponds of Chengdu City should be strengthened.
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