Photo-transformation of nitrate and fulvic acid driven by guest iron minerals  

作　　者：Na Huang Yuanyuan Chen Xuyin Yuan Yingying Li Yin Lu Yilan Jiang Huacheng Xu Lingxiao Ren Dawei Wang 

机构地区：[1]Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes(Ministry of Education),College of Environment,Hohai University,Nanjing 210098,China [2]State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China [3]School of Environmental Engineering,Nanjing Institute of Technology,Nanjing 210008,China

出　　处：《Frontiers of Environmental Science & Engineering》2025年第1期115-128,共14页环境科学与工程前沿(英文)

基　　金：the financial support from the National Natural Science Foundation of China(Nos.52100178,52370072,and 42361144873);the Natural Science Foundation of Jiangsu Province(BK20210933).

摘　　要：The photochemical interactions between nitrate(NO_(3)^(-))and natural organic matter(NOM)are vital for aquatic chemistry.However,the effects of guest iron minerals,which may enter the aquatic environments due to both human and natural activities,on those interactions are widely ignored.This work evaluated the effects of hematite(α-Fe_(2)O_(3))on the photochemical conversion products and pathways of NO_(3)^(-),fulvic acid(FA)under 12 h of ultraviolet irradiation.The addition of 0.4 g/L of guestα-Fe_(2)O_(3)accelerated the reduction of NO_(3)^(-)by 24.3%,with NH4+as the primary reduction product,and hampered the mineralization of FA.These effects were dependent on the dosage amount ofα-Fe2O3 and FA concentrations.The studies on the molecule-level changes of FA revealed that the complete oxidation to CO_(2)and the partial oxidation pathways that alter the molecular composition of FA were suppressed,and the mineralization rate decreased by 27.8%.Particularly,the conversion rates of CHON and CHONS were reduced by 21.0%and 20.3%,respectively,increasing the unsaturated products.The scavenging experiments and quantitative measurements of hydroxyl radicals(•OH)proposed that the photogenerated electrons and holes fromα-Fe_(2)O_(3)were the key for the altered transformation of NO3-and FA.This work revealed the guest effects of iron mineral particles on the photochemical interactions between NO_(3)^(-)and NOM in the natural surface waters.

关 键 词：Guest iron minerals PHOTOCHEMISTRY NITRATE Fulvic acid CONVERSION 

分 类 号：O62[理学—有机化学]