摘要
周期性的水位变化导致鄱阳湖形成面积较大的环湖消落区,是重金属重要的汇源地.本文在鄱阳湖湿地选择12个采样区域,按照不同植被带采集180个土壤样品,分析环鄱阳湖消落区重金属(Cd、Co、Cu、Mn、Mo、Ni、Pb、Ti、V和Zn)含量特征及赋存形态,评价消落区重金属的生态风险,探究土壤重金属赋存形态的影响因素.结果表明,消落区重金属均值含量排序为Ti>Mn>V>Zn>Cu>Ni>Pb>Co>Mo>Cd,除Ti和Pb外,重金属均值含量均明显高于江西省土壤背景值(中位数),其中Cd含量是背景值的11.73倍.消落区Co、Ni、Ti、V和Mo的赋存主要以残渣态为主,而Cu、Zn、Cd、Mn次生相占比较高,特别是Cd和Mn存在较高的比例.不同植被带重金属含量及赋存形态存在明显的差异,但并未表现出一致的分布规律.综合风险评估指数法(RAC)和次生相与原生相比值法(RSP)结果表明,Cd和Mn存在较高的污染和生态风险.RDA综合排序发现,pH对重金属不同形态均有显著的调节作用;有机碳是影响重金属全量、可还原态(F2)、可氧化态(F3)的重要因子;全磷可调节重金属酸溶解态(F1)和可氧化态,而全氮主要影响重金属可还原态和残渣态(F4);粉粒对可氧化态和残渣态有显著的调节作用.研究结果可为鄱阳湖湿地重金属污染防治提供科学依据和理论支撑.
The rhythmic water level changes lead to the formation of a large water-level-fluctuating area in the Poyang Lake,which is an important source and sinks for heavy metals in the wetland.In this study,180 soil samples were collected from 12 sampling areas in the water-level-fluctuating wetland to analyze the concentrations and chemical fraction of heavy metals(Cd,Co,Cu,Mn,Mo,Ni,Pb,Ti,V,and Zn),and to evaluate the ecological risk of heavy metals and explore the influencing factors of chemical fraction of heavy metals.The results showed that the mean concentrations of heavy metals ranked as Ti>Mn>V>Zn>Cu>Ni>Pb>Co>Mo>Cd in the water-level-fluctuating area,and the levels of heavy metals were obviously higher than their corresponding soil background values from Jiangxi Province(median),except Ti and Pb,and Cd concentration was 11.73 times higher than its background value.The chemical fraction of Co,Ni,Ti,V and Mo were mainly in residual state,while the secondary phases of Cu,Zn,Cd and Mn were relatively high,especially for Cd and Mn.There were significant differences of the concentrations and chemical fractions of heavy metals in different vegetation zones,but they did not follow a consistent distribution pattern.The results from Risk Assessment Code(RAC)and ratio of secondary phase and primary phase(RSP)showed that Cd and Mn had higher pollution and ecological risks.Redundancy analysis(RDA)indicated that pH significantly regulated chemical fractions of heavy metals;soil organic carbon(SOC)was an important factor affecting the total,reducible(F2)and oxidizable(F3)fraction of heavy metals.Total phosphorus(TP)regulated the acid-soluble(F1)and oxidizable fraction of heavy metals,whereas total nitrogen (TN) mainly affected the reducible and residual (F4) fraction of heavy metals;silt content had a significant regulating effect on oxidizable and residue state;The results of this study can provide scientific basis and theoretical support for the prevention and control of heavy metal enrichments in the Poyang Lake.
作者
邹天娥
丁明军
张华
尧波
曾欢
黄鹏
徐欢
杨宇涛
邹福
陈红梅
吴宇萍
ZOU Tian´e;DING Mingjun;ZHANG Hua;YAO Bo;ZENG Huan;HUANG Peng;XU Huan;YANG Yutao;ZOU Fu;CHEN Hongmei;WU Yuping(School of Geography and Environment,Jiangxi Normal University,Nanchang 330022;Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang 330022)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第3期354-364,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.42061018)。
关键词
鄱阳湖
消落区
重金属
赋存形态
BCR
the Poyang Lake
water-level-fluctuating area
heavy metals
chemical fraction
BCR
作者简介
邹天娥(1996—),女,E-mail:1300709612@qq.com;张华,责任作者,E-mail:zhangh2013@jxnu.edu.cn。
