Molecular characteristics of dissolved organic phosphorus in watershed runoff:Coupled influences of land use and precipitation  

作　　者：Zhanyao Shi Yao Du Hongni Liu Yamin Deng Yiqun Gan Xianjun Xie 

机构地区：[1]State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution,China University of Geosciences,Wuhan 430078,China [2]Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science,China University of Geosciences,Wuhan 430078,China [3]School of Environmental Studies&State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China

出　　处：《Journal of Environmental Sciences》2025年第2期387-398,共12页环境科学学报(英文版)

基　　金：supported by the Three Gorges Corporation (No.HBHB2023018);the Project of Hubei Provincial Key Research and Development (No.2022BCA074);the National Key Research and Development Program of China (No.2022YFC3705002).

摘　　要：Land use and precipitation are two major factors affecting phosphorus(P)pollution of watershed runoff.However,molecular characterization of dissolved organic phosphorus(DOP)in runoff under the joint influences of land use and precipitation remains limited.This study used Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS)to study the molecular characteristics of DOP in a typical P-polluted watershed with spatially variable land use and precipitation.The results showed that low precipitation and intense human activity,including phosphate mining and associated industries,resulted in the accumulation of aliphatic DOP compounds in the upper reaches,characterized by low aromaticity and low biological stability.Higher precipitation and widespread agriculture in the middle and lower reaches resulted in highly unsaturated DOP compounds with high biological stability constituting a higher proportion,compared to in the upper reaches.While,under similar precipitation,more aliphatic DOP compounds characterized by lower aromaticity and higher saturation were enriched in the lower reaches due to more influence from urban runoff relative to the middle reaches.Photochemical and/or microbial processes did result in changes in the characteristics of DOP compounds during runoff processes due to the prevalence of low molecular weight and low O/C bioavailable aliphatic DOP molecules in the upper reaches,which were increasingly transformed into refractory compounds from the upper tomiddle reaches.The results of this study can increase the understanding of the joint impacts of land use and precipitation on DOP compounds in watershed runoff.

关 键 词：Watershed runoff DOP FT-ICR MS Land use PRECIPITATION 

分 类 号：X52[环境科学与工程—环境工程]