摘要
【目的】以环渤海典型滨海湿地为研究对象,开展重金属铜(Cu)在不同水位深度沉积物中的行为机制研究,探明Cu的污染状况及其在沉积物中与多种组分间的微尺度结合信息。【方法】采用化学提取和同步辐射红外显微成像(SR-FTIR)结合微束X射线荧光(μ-XRF)技术对湿地沉积物中Cu的结合特征进行分析,原位探究微米尺度上沉积物中Cu、矿物组分和不同官能团之间的分布规律及结合特征。【结果】北大港湿地沉积物中总碳、总氮和有机碳的含量随着沉积物深度的增加而降低;不同水位深度采样点处Cu的富集系数(EF)均小于2,潜在生态风险指数(RI)均小于40,表明Cu在该处属于轻度富集和低生态风险;表层沉积物中Cu与含铁矿质组分、黏土类、碳酸盐类和矿质类(Si/Al)官能团呈现相似的分布规律,而底层沉积物中矿质组分与Cu具有较明显的结合特征。【结论】滨海湿地不同水位深度表层和底层沉积物中Cu处于轻度富集和低生态风险状态。表层和底层沉积物中Cu的空间分布和微尺度结合特征存在差异,表层沉积物中矿质组分和有机物均与Cu表现出明显的结合特征,而底层沉积物中则表现出矿质组分对Cu的结合起主导作用。研究结果可对当前受污染湿地系统的修复和健康可持续利用提供重要的技术和理论指导。
[Objective]The pollution status of copper(Cu)and its microscale combination information with various components in sediments around the Bohai Bay,the behavior mechanism of Cu in sediments at various water levels and depths was studied in coastal wetlands around the Bohai Bay.[Method]Chemical extraction and synchrotronradiation(SR)-based Fourier transform infrared(FTIR)spectro-microscopy combined with micro X-ray fluorescence(μ-XRF)were used to investigate the characteristics of Cu in wetland sediments.The distribution and combination characteristics of Cu,mineral components,and different functional groups were also explored in situ at micro-scale.[Result]The concentrations of total carbon,total nitrogen,and organic carbon in the sediments of Beidagang wetland decreased with depth of sediment.The enrichment factor(EF)and potential ecological risk index(RI)of Cu at different sampling sites were less than 2 and less than 40,respectively,indicating that Cu is slightly enriched and has low ecological risk.In surface sediments,the distribution of Cu was familiar with that of iron-bearing components,clay minerals/carbonates,and mineral(Si/Al)functional groups,while mineral compounds had obvious binding characteristics to Cu in the bottom sediments.[Conclusion]Cu in surface and bottom sediments of coastal wetlands at different water levels is in a state of slight enrichment and low ecological risk.The spatial distribution and micro-scale binding characteristics of Cu in surface and bottom sediments are different.Mineral components and organic matter in surface sediments show obvious binding characteristics with Cu,while mineral components play a leading role in Cu binding in bottom sediments.These results can provide valuable technical and theoretical guidance for restoring current polluted wetlands and ensuring their healthy and sustainable utilization.
作者
姜程程
孙富生
余光辉
JIANG Cheng-cheng;SUN Fu-sheng;YU Guang-hui(School of Earth System Science,Tianjin University,Tianjin 300070,China)
出处
《土壤通报》
CAS
CSCD
北大核心
2024年第1期193-203,共11页
Chinese Journal of Soil Science
基金
国家自然科学基金项目(42107401)
国家重点研发项目(2020YFC1806803)资助。
关键词
滨海湿地
湿地沉积物
铜
微尺度分布
同步辐射光谱
Coastal wetland
Wetland sediment
Copper
Microscale distribution
Synchrotron-radiation-based spectro-microscopy
