Risk assessment and binding mechanisms of potentially toxic metals in sediments from different water levels in a coastal wetland  

作　　者：Fusheng Sun Guanghui Yu Xingxing Han Zhilai Chi Yunchao Lang Congqiang Liu 

机构地区：[1]Institute of Surface-Earth System Science,School of Earth System Science,Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim,Tianjin University,Tianjin 300072,China

出　　处：《Journal of Environmental Sciences》2023年第7期202-212,共11页环境科学学报（英文版）

基　　金：This work was funded by the National Natural Science Foundation of China(Nos.42107401 and 41977271);the National Key Research and Development Program of China(No.2020YFC1806803).

摘　　要：The excessive accumulation of potentially toxic metals(Pb and Cd)in coastal wetlands is among the main factors threateningwetland ecosystems.However,the effects ofwater table depth(WTD)on the risk and binding mechanisms of potentially toxic metals in sediments remain unclear.Here,sediments from different WTD obtained from a typical coastal wetland were evaluated using a newly developed strategy based on chemical extraction methods coupled with high-resolution spectroscopy.Our findings indicated that the WTD of the coastal wetland fluctuates frequently and the average enrichment factor for Pb was categorized as minor,whereas Cd enrichment was categorized as moderate.High-resolution spectroscopy techniques also demonstrated that organic functional groups and partly inorganic compounds(e.g.,Fe-O/Si-O)played a vital role in the binding of Pb and Cd to surface sediments.Additionally,mineral components rather than organic groups were mainly bound to thesemetals in the bottom sediments.Collectively,our findings provide key insights into the potential health effects and binding characteristics of potentially toxic metals in sediments,as well as their dynamic behavior under varying sediment depths at a microscale.

关 键 词：Coastal wetlands Wetland sediment Toxic metals Risk assessment Synchrotron radiation Binding mechanisms 

分 类 号：X52[环境科学与工程—环境工程] X820.4