Composition regulates dissolved organic matter adsorption onto iron (oxy)hydroxides and its competition with phosphate: Implications for organic carbon and phosphorus immobilization in lakes  

作　　者：ShuaiLong Wen JingJing Liu YueHan Lu JiaRu Dai XiuLin Huang ShiLin An Erik Jeppesen ZhengWen Liu YingXun Du 

机构地区：[1]State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Molecular Eco-Geochemistry(MEG)Laboratory,Department of Geological Sciences,The University of Alabama,2017th Ave,Tuscaloosa,AL 35485,USA [4]School of Environmental Science and Engineering,Nanjing Tech University,Nanjing 210008,China [5]School of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404020,China [6]Department of Ecoscience,Aarhus University,Silkeborg 8600,Denmark [7]Sino-Danish Centre for Education and Research,University of Chinese Academy of Sciences,Beijing 101408,China [8]Limnology Laboratory,Department of Biological Sciences and Centre for Ecosystem Research and Implementation,Middle East Technical University,Ankara 06800,Turkey

出　　处：《Journal of Environmental Sciences》2024年第10期159-171,共13页环境科学学报（英文版）

基　　金：This study was supported by the National Natural Science Foundation of China(Nos.32330068,41971139,42271117,and 41930760);the Natural Science Foundation of Jiangsu Province(No.BK20220015);the Science and Technology Planning Project of NIGLAS(No.NIGLAS2022GS09).

摘　　要：Dissolved organicmatter(DOM)is a heterogeneous pool of compounds and exhibits diverse adsorption characteristics with or without phosphorous(P)competition.The impacts of these factors on the burial and mobilization of organic carbon and P in aquatic ecosystems remain uncertain.In this study,an algae-derived DOM(ADOM)and a commercially available humic acid(HA)with distinct compositions were assessed for their adsorption behaviors onto iron(oxy)hydroxides(FeOx),both in the absence and presence of phosphate.ADOM contained less aromatics but more protein-like and highly unsaturated structures with oxygen compounds(HUSO)than HA.The adsorption capacity of FeOx was significantly greater for ADOM than for HA.Protein-like and HUSO compounds in ADOM and humic-like compounds and macromolecular aromatics in HA were preferentially adsorbed by FeOx.Moreover,ADOM demonstrated a stronger inhibitory effect on phosphate adsorption than HA.This observation suggests that the substantial release of autochthonous ADOM by algae could elevate internal P loading and pose challenges for the restoration of restore eutrophic lakes.The presence of phosphate suppressed the adsorption of protein-like compounds in ADOM onto FeOx,resulting in an increase in the relative abundance of protein-like compounds and a decrease in the relative abundance of humic-like compounds in post-adsorption ADOM.In contrast,phosphate exhibited no discernible impact on the compositional fractionation of HA.Collectively,our results show the source-composition characters of DOM influence the immobilization of both DOM and P in aquatic ecosystems through adsorption processes.The preferential adsorption of proteinaceous compounds within ADOM and aromatics within HA highlights the potential for the attachment with FeOx to diminish the original source-specific signatures of DOM,thereby contributing to the shared DOM characteristics observed across diverse aquatic environments.

关 键 词：Algal dissolved organic matter Humic acid ADSORPTION PHOSPHATE Fractionation FT-ICR MS 

分 类 号：O64[理学—物理化学] X52[理学—化学]