白洋淀潜在新增淹没区土壤重金属赋存形态及生态风险评价  

Speciation and ecological risk assessment of heavy metals in soil of potential new submerged area in Baiyangdian Lake

作　　者：邓旭东 张超[2] 翟付杰 李思敏 单保庆[2,3] DENG Xudong;ZHANG Chao;ZHAI Fujie;LI Simin;SHAN Baoqing(College of Energy and Environmental Engineering,Hebei University of Engineering,Handan 056038;State Key Laboratory of Environmental Aquatic Chemisty,Research Center for Eco-Environment Sciences,Chinese Academy of Sciences,Beijing 100085;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]河北工程大学能源与环境工程学院,邯郸056038 [2]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085 [3]中国科学院大学,北京100049

出　　处：《环境科学学报》2023年第5期398-408,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.41907267)。

摘　　要：随着白洋淀水位的持续增高,水域周围低洼田地将被淹没,各种污染物将释放至水环境中,评估潜在新增淹没区土壤重金属污染情况对白洋淀的水生态安全至关重要.根据陆地高程情况,采集白洋淀6.5~7.5 m(85高程)内潜在新增淹没区表层土壤,采用改进的BCR连续化学提取法对土壤中Cd、Cr、Ni、Cu、Pb、Zn 6种重金属元素进行形态分析,并运用地累积指数法、潜在生态风险指数法、毒性风险指数法、风险评估编码法等多种方法进行污染评估与生态风险评价.结果表明,Cd、Cr、Ni、Cu、Pb、Zn元素含量均值分别为河北省土壤背景值的2.20、1.10、1.20、1.47、1.27和1.03倍.Cd元素酸可提取(F1)态质量分数最高,达到54.18%,其次为可还原态(F2)的34.43%;Pb主要以F2态存在,占比达到58.73%,;Ni以可氧化态(F3)为主,导致其次生相与原生相比值(RSP值)偏高;Cu、Zn、Cr元素主要以残渣态为主,迁移能力较低.风险评价结果来看,研究区域土壤重金属生态风险整体处于中等或偏低水平,但Cd具有较高的可迁移性和释放风险,表明白洋淀新增淹没区土壤重金属污染的治理工作重点关注Cd.The lower terrain near open water will be submerged and the pollutants can be released into the aquatic environment with the continuous increase of water stage in Baiyangdian Lake.Therefore,assessment of heavy metals pollution in the potential submerged soil is crucial to the aquatic ecological security of Baiyangdian Lake.According to the land elevation,the surface soil samples were collected from the potential new submerged area of Baiyangdian Lake within 6.5~7.5 m(elevation 85).Speciation analysis of Cd,Cr,Ni,Cu,Pb,Zn in soil by improved BCR sequential chemical extraction.Assessment of pollution degree and ecological risk by using various methods such as potential ecological risk index,toxicity risk index,and risk assessment code.The results demonstrated that the average values for Cd,Ni,Cu,Pb and Zn were 2.20,1.10,1.20,1.47,1.27 and 1.03 times greater than the background values of Hebei Province,respectively.For Cd,the acid soluble fraction(F1)was the highest(54.18%),followed by the reducible fraction(34.43%).Ni is mainly in the oxidizable fraction(F3),resulting in a higher secondary phase relative to the primary phase(RSP value).The elements of Cu,Zn and Cr are mainly in residual fraction with low migration ability.Risk assessment results showed that the potential ecological risk of heavy metals in the study area was moderately low.However,Cd has high mobility and release capacity,indicating that the Cd as a priority pollutant should be concerned in new submerged area of Baiyangdian Lake.

关 键 词：白洋淀 潜在新增淹没区 重金属 形态分布 风险评价 

分 类 号：X53[环境科学与工程—环境工程] X820.4