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
In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge （DSS）, the preparation and properties of lightweight sludge ceramic （LSC） and the mechanisms of action of the organic ...In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge （DSS）, the preparation and properties of lightweight sludge ceramic （LSC） and the mechanisms of action of the organic and inorganic foaming agents （OFAs and IFAs）. The chemical components and thermal properties of the raw materials were studied by Energy Dispersive X-ray Detection （EDX） and Thermogravimetric Analysis and Differential Scanning Calorimetry （DSC/TGA）. The mineral phases of the raw materials and the formed ceramics were determined by X-ray Diffraction （XRD）. The leaching characteristics of heavy metals were investigated with inductively Coupled Plasma Atomic Emission Spectrometry （ICP-AES）. Different ratios of DSS and clay were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at 1150℃ for 10 rain. The physical properties of LSC （50 wt% DSS added） were tested. The results showed that when the addition of DSS was above 50 wt%, LSC began to shrink, and a maximum density occurred. The environmental safety of LSC was satisfactory. XRD showed that some new mineral phases formed in the LSC. Observation of the microstructure by Scanning Electron Microscope （SEM） indicated that the body of LSC was porous.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.
文摘In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge （DSS）, the preparation and properties of lightweight sludge ceramic （LSC） and the mechanisms of action of the organic and inorganic foaming agents （OFAs and IFAs）. The chemical components and thermal properties of the raw materials were studied by Energy Dispersive X-ray Detection （EDX） and Thermogravimetric Analysis and Differential Scanning Calorimetry （DSC/TGA）. The mineral phases of the raw materials and the formed ceramics were determined by X-ray Diffraction （XRD）. The leaching characteristics of heavy metals were investigated with inductively Coupled Plasma Atomic Emission Spectrometry （ICP-AES）. Different ratios of DSS and clay were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at 1150℃ for 10 rain. The physical properties of LSC （50 wt% DSS added） were tested. The results showed that when the addition of DSS was above 50 wt%, LSC began to shrink, and a maximum density occurred. The environmental safety of LSC was satisfactory. XRD showed that some new mineral phases formed in the LSC. Observation of the microstructure by Scanning Electron Microscope （SEM） indicated that the body of LSC was porous.
