Xu Meng-Ya, Zhang Chao, Shan Bao-Qing, Liu Cao
College of Environment, Liaoning University, Shenyang 110036, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Huan Jing Ke Xue. 2022 Sep 8;43(9):4532-4542. doi: 10.13227/j.hjkx.202110151.
The morphological characteristics of Cd, Cr, Cu, Ni, Pb, and Zn in sediments were analyzed using an improved BCR extraction method in four water types of Baiyangdian Lake:watercourse, trench, lake surface, and fish pond. The potential ecological risk index, secondary and primary phases, and risk assessment codes were used to systematically assess the pollution level and ecological risk of heavy metals in surface sediments. The results showed that:① the mean contents of heavy metals Cd, Cu, and Zn in the sediments were 0.37, 28.49, and 83.08 mg·kg, respectively, 94.91%, 73.91%, and 46.39% of which exceeded the soil background value. ② Cd was dominated by the non-residual fraction (F1+F2+F3) with a fraction ranging from 54% to 97%, whereas Cr was dominated by the residual fraction (F4) with a mass fraction ranging from 87% to 99%. Cu, Ni, Pb, and Zn were mainly in the fraction of residual fraction. In the non-residual fraction, Cu and Ni were mainly in the oxidizable fraction (F3) state, whereas Pb and Zn were mainly in the reducible fraction (F2) state. ③ The RAC risk assessment results showed that there were 68.97%, 39.89%, 54.84%, and 49.78% points in channel, trench, open water, and fish pond samples, respectively, of Cd at high risk. The Cu, Ni, and Pb were at low risk. In general, the overall heavy metal pollution level in Baiyangdian Lake was low, but Cd had ecological risk and high bioavailability in the Fuhe River of the Nanliuzhuang area and the Baigouyin River.
采用改进的BCR萃取法，分析了白洋淀四种水体类型（水道、沟渠、湖面和鱼塘）沉积物中镉（Cd）、铬（Cr）、铜（Cu）、镍（Ni）、铅（Pb）和锌（Zn）的形态特征。运用潜在生态风险指数、次生相与原生相以及风险评估代码，系统评估了表层沉积物中重金属的污染程度和生态风险。结果表明：①沉积物中重金属Cd、Cu和Zn的平均含量分别为0.37、28.49和83.08mg·kg，其中94.91%、73.91%和46.39%超过土壤背景值。②Cd以非残渣态（F1+F2+F3）为主，占比54%97%，而Cr以残渣态（F4）为主，质量分数为87%99%。Cu、Ni、Pb和Zn主要存在于残渣态部分。在非残渣态中，Cu和Ni主要以可氧化态（F3）存在，而Pb和Zn主要以可还原态（F2）存在。③RAC风险评估结果显示，Cd在水道、沟渠、开阔水域和鱼塘样品中的高风险点位分别为68.97%、39.89%、54.84%和49.78%。Cu、Ni和Pb处于低风险。总体而言，白洋淀整体重金属污染水平较低，但在南刘庄地区的府河和白沟引河，Cd存在生态风险且生物有效性较高。
