Effects of acid mine drainage on photochemical and biological degradation of dissolved organic matter in karst river water  

作　　者：Linwei Li Xingxing Cao Chujie Bu Pan Wu Biao Tian Yongheng Dai Yeye Ren 

机构地区：[1]College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China [2]Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China [3]Guizhou Karst Environmental Ecosystems Observation and Research Station,Ministry of Education,Guizhou University,Guiyang 550025,China

出　　处：《Journal of Environmental Sciences》2024年第1期26-38,共13页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.42163003);the High-Level Talent Training Program in Guizhou (No.[2016]5664);the Project of Talent Base in Guizhou Province (No.RCJD2018-21);the Talent Introduction Project of Guizhou University (No.[2019]24)。

摘　　要：Dissolved organic matter(DOM)can be removed or transformed by photochemical and biological processes,producing the negative effect of transforming organic carbon into inorganic carbon,which plays a vital role in the karst carbon cycle.However,acid mine drainage(AMD)will affect this process,so the degradation of DOM in karst river water(KRW)needs to be studied in this context.In this study,to reveal the evolution processes of DOM under photochemical and biological conditions in AMD-impacted KRW,AMD and KRW were mixed in different ratios under conditions of visible light irradiation(VL),biodegradation(BD),ultraviolet irradiation(UV)and ultraviolet irradiation+biodegradation(UV+BD).The average DOC concentrations in samples after mixing AMD and KRW in different proportions decreased significantly(by 23%)in UV+BD,which was 1.2–1.4 times higher than under the other conditions and would lead to a significant release of inorganic carbon.Further analysis of the fluorescence parameters via parallel factor analysis(PARAFAC)revealed that the DOM fluorescence components in AMD comprised mainly protein-like substances derived from autochthonous components,while the DOM fluorescence components in KRW were mainly humic-like substances with both autochthonous and allochthonous sources.Therefore,AMD could promote both the photochemical and biological degradation of DOM in karst receiving streams,resulting in the conversion of DOC to inorganic carbon.The results showed that the synergistic effects of UV+BD and AMD accelerated the degradation of DOM and the release of inorganic carbon in KRW,thus affecting the stability of the karst carbon cycle.

关 键 词：Acid mine drainage Dissolved organic matter Karst river water Photochemical degradation Biological degradation 

分 类 号：X75[环境科学与工程—环境工程] X52