Synergistic effect of silicon availability and salinity on metal adsorption in a common estuarine diatom  

作　　者：Fengyuan Chen Jie Ma Ke Pan 

机构地区：[1]SZU-HKUST Joint PhD Program in Marine Environmental Science,Shenzhen University,Shenzhen 518060,China [2]Shenzhen Key Laboratory of Marine Microbiome Engineering,Institute for Advanced Study,Shenzhen University,Shenzhen 518060,China [3]Department of Ocean Science,The Hong Kong University of Science and Technology,Hong Kong 999077,China

出　　处：《Journal of Environmental Sciences》2025年第2期364-374,共11页环境科学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China (Nos.U23A2048,42376152,41976140,and 42076148);the Special Program of Key Sectors in Guangdong Universities (Nos.2022ZDZX4040 and 2023KCXTD028).

摘　　要：Increasing nitrogen and phosphorus discharge and decreasing sediment input have made silicon(Si)a limiting element for diatoms in estuaries.Disturbances in nutrient structure and salinity fluctuation can greatly affect metal uptake by estuarine diatoms.However,the combined effects of Si and salinity on metal accumulation in these diatoms have not been evaluated.In this study,we aimed to investigate how salinity and Si availability combine to influence the adsorption of metals by a widely distributed diatom Phaeodactylum tricornutum.Our data indicate that replete Si and low salinity in seawater can enhance cadmium and copper adsorption onto the diatom surface.At the single-cell level,surface potential was a dominant factor determining metal adsorption,while surface roughness also contributed to the highermetal loading capacity at lower salinities.Using a combination of noninvasive micro-test technology,atomic force microscopy,X-ray photoelectron spectroscopy,and Fourier transform infrared spectroscopy,we demonstrate that the diversity and abundance of the functional groups embedded in diatom cell walls vary with salinity and Si supply.This results in a change in the cell surface potential and transient metal influx.Our study provides novel mechanisms to explain the highly variable metal adsorption capacity of a model estuarine diatom.

关 键 词：DIATOM Metal adsorption SILICON SALINITY Functional group Surface potential 

分 类 号：X701[环境科学与工程—环境工程]