宁夏阅海底泥重金属空间分布特征及来源解析 |
Spatial Distribution Characteristics and Source Analysis of Heavy Metals in the Sediments of Yuehai Lake, Ningxia |
投稿时间:2020-04-16 修订日期:2022-03-24 |
DOI:10.15928/j.1674-3075. 202004160105 |
中文关键词:底泥重金属 空间分布 生态风险 同源性 宁夏阅海 |
英文关键词:sediment heavy metals spatial distribution ecological risk assessment homology analysis Ningxia Yuehai Lake |
基金项目:宁夏回族自治区重点研发计划重大(重点)项目(2018BFG02002) |
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中文摘要: |
为了解宁夏阅海底泥重金属污染现状及其潜在生态风险,解析其重金属污染物来源,结合环境现状,分区域采集14个底泥样品,分析底泥理化性质;运用Arcgis反距离空间插值法(IDW)进行空间插值,研究阅海底泥重金属元素空间分布特征;采用地累积指数法和Hakanson潜在生态危害指数法对其污染状况和生态风险进行评估,并利用相关性、主成分以及聚类分析等方法对阅海底泥重金属来源进行解析。结果表明,阅海底泥中汞(Hg)和钴(Co)元素平均含量分别为0.16 mg/kg和19.23 mg/kg,分别达到背景值的5.16和2.24倍,其他重金属元素铅(Pb)、铜(Cu)、砷(As)、镉(Cd)、铬(Cr)含量均超过银川平原引黄灌区土壤对应元素背景值含量;阅海底泥重金属空间分布差异性显著,各重金属元素在芦苇分布区域富集趋势十分明显;重金属元素污染程度表现为:Hg>Co>Pb>Cu>Cd>As>Cr,单项潜在生态风险Hg元素处于很强生态危害范畴,综合潜在生态风险均值达到277.21,属中等生态危害范畴,其中Hg元素超标严重,其贡献率达74.42 %。阅海底泥重金属Cr和As元素受自然背景影响明显,而Hg、Co、Pb、Cu和Cd元素则主要来源于鸟粪排放以及人类活动。 |
英文摘要: |
Yuehai Lake is an urban lake located in Yinchuan City, Ningxia Hui Autonomous Region. It is an integrated ecological system with some remaining original landscape, and environmental degradation in and around the lake is cause for concern. In this study, we explored the status and potential ecological risk of heavy metal pollution in Yuehai Lake sediments and analyzed heavy metal sources. The aim was to support conservation of the ecology and to prevent and control pollution of the Yuehai Lake wetland. In October 2018, sediment samples were collected at 14 sampling sites (Q1-Q5 in shallow waters, S1-S4 in deep waters, L1-L3 in the reeds, B1 at the inlet and P1 at the outlet) of Yuehai Lake for determination of sediment physicochemical properties and heavy metal concentrations (Cr, Pb, Cu, As, Hg, Cd and Co). ArcGIS inverse distance weighting (IDW) was used to study the spatial distribution of heavy metals in Yuehai Lake sediment. The geoaccumulation index and Hakanson potential ecological hazard index were used to evaluate the pollution status and potential ecological risk of heavy metals. Heavy metal sources to Yuehai Lake sediments were analyzed using correlation analysis, principal component analysis and cluster analysis. Average concentrations of Cr, Pb, Cu, As, Hg, Cd and Co in the sediment of Yuehai Lake were, respectively, 59.24, 19.38, 27.04, 12.94, 0.16, 0.10 , 19.23 mg/kg. All heavy metal concentrations exceeded background values for heavy metals in the Yellow River Irrigation Area of Yinchuan Plain, and the content of Hg and Co were 5.16 times and 2.24 times the background values. The spatial distributions of the heavy metals were significantly different and heavy metal enrichment was obvious in the reed area with high bird activity. The pollution degree of heavy metals followed the order Hg>Co>Pb>Cu>Cd>As>Cr. The single potential ecological risk index of Hg averaged 243.90, indicating serious ecological risk, while the potential ecological risks of other heavy metals were at a slight level, following the order of Hg > Cd > Co > As > Pb > Cu >Cr. Spatially, the single potential ecological risk followed the order reeds > deep water > water outlet > shallow water > water inlet. The average value of the comprehensive potential ecological risk of heavy metals was 277.21 in the Yuehai Lake, indicating medium ecological hazard. Hg greatly exceeded the standard, with a contribution rate of 74.42%. Source analysis showed that Cr and As were affected by natural background levels in Yuehai Lake sediment, while Hg, Co, Pb, Cu, and Cd were contributed primarily by bird excrement and human activities. In addition, there was a significant correlation between heavy metal levels and sediment particle size. Therefore, increasing the clay content and reducing the silt component of the sediment would enhance sediment carrying capacity and reduce heavy metal release from the sediment. Further, prevention and control of Hg pollution and clear source identification are the key issues to be resolved. |
马正虎,璩向宁,何志润,赵希妮,刘雅清,张矞勋,杨 蕾.2022.宁夏阅海底泥重金属空间分布特征及来源解析[J].水生态学杂志,43(2):116-124. |
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