Residual enrofloxacin(ENR)exposed in aqueous environments is challenging to the ecosphere.In this work,a layered double hydroxide CoAl-LDH was used to activate the common oxidizing agent persulfate(PS)for photodegrada...Residual enrofloxacin(ENR)exposed in aqueous environments is challenging to the ecosphere.In this work,a layered double hydroxide CoAl-LDH was used to activate the common oxidizing agent persulfate(PS)for photodegradation of ENR,and the degradation pathways of ENR were scrutinized and elucidated.The results indicated that,under the optimal conditions obtained through orthogonal experiments,even though the degradation rate of ENR was as high as 97.72%,the removal of total organic carbon(TOC)from the system was only about 30%.Eleven probable reaction pathways were categorized,and thirty-one types of intermediates were identified in participating in the complex degradation process.The major products of ENR were P4(C_(17)H_(20)FN_(3)O_(3)),P22(C_(19)H_(22)FN_(3)O_(4)),P19(C_(17)H_(18)FN_(3)O_(3)),which are mainly derived from the cleavage of the piperazine groups and quinolone rings.Density functional theory(DFT)calculations of the Fukui index for ENR revealed that the two N atoms in the piperazine ring were the core reactive sites in triggering the degradation chains,which were sensitive for electrophilic attack by the dominant radicals(·OH and SO_(4)·^(-))generated from the composite PS-UV-CoAl-LDH system.展开更多
基金support from the National Key Research and Development Program of China(2022YFE0104900)Foshan Shunde District Core Technology Breakthrough Project(2230218004273)+1 种基金2022 Zhuhai Social Development Science and Technology Program Project(2220004000355)Guangdong Basic and Applied Basic Research Foundation(2023B1515040028).
文摘Residual enrofloxacin(ENR)exposed in aqueous environments is challenging to the ecosphere.In this work,a layered double hydroxide CoAl-LDH was used to activate the common oxidizing agent persulfate(PS)for photodegradation of ENR,and the degradation pathways of ENR were scrutinized and elucidated.The results indicated that,under the optimal conditions obtained through orthogonal experiments,even though the degradation rate of ENR was as high as 97.72%,the removal of total organic carbon(TOC)from the system was only about 30%.Eleven probable reaction pathways were categorized,and thirty-one types of intermediates were identified in participating in the complex degradation process.The major products of ENR were P4(C_(17)H_(20)FN_(3)O_(3)),P22(C_(19)H_(22)FN_(3)O_(4)),P19(C_(17)H_(18)FN_(3)O_(3)),which are mainly derived from the cleavage of the piperazine groups and quinolone rings.Density functional theory(DFT)calculations of the Fukui index for ENR revealed that the two N atoms in the piperazine ring were the core reactive sites in triggering the degradation chains,which were sensitive for electrophilic attack by the dominant radicals(·OH and SO_(4)·^(-))generated from the composite PS-UV-CoAl-LDH system.
