Diatomite supported nano zero valent iron(n ZVI)catalyst(NDA)with complex network structure was prepared via a mild reduction precipitation method in this work.The pore structure and pore distribution of NDA can be re...Diatomite supported nano zero valent iron(n ZVI)catalyst(NDA)with complex network structure was prepared via a mild reduction precipitation method in this work.The pore structure and pore distribution of NDA can be regulated and controlled through adjusting the loading amount of n ZVI.In general,the nano three-dimensional network formed by n ZVI and diatomite channels greatly increase the specific surface area and pore volume of NDA,and further formed more active sites,which made NDA have better performance in activating PMS to degrade BPA than pure n ZVI.The pseudo-first-order reaction rate constant of 50-NDA(50%-n ZVI/diatomite)is almost 3 times higher than that of pure n ZVI.Besides,the electron paramagnetic resonance(EPR)and radical quenching experiments showed that the activation process was dominated by the sulfate radical(SO_(4)^(-))and hydroxyl radical(·OH)produced by Fe;oxidation.The generated electrons promote the self-decomposition of PMS to produce singlet oxygen(^(1)O_(2)),and then the valence state of iron changes to produce free radicals.In addition,the possible degradation pathway of BPA was inferred from the intermediate products identified by liquid chromatograph-mass spectrometer(LC-MS).This study provides a novel strategy for the design and preparation of three-dimensional composite catalysts derived from natural mineral.展开更多
Two amino-functionalized diatomite(DE)composites modified by 3-aminopropyltriethoxysilane(APTS)or glycine(GLY)(i.e.,APTS/DE and GLY/DE)were successfully synthesized via the wet chemical method for the time-and cost-ef...Two amino-functionalized diatomite(DE)composites modified by 3-aminopropyltriethoxysilane(APTS)or glycine(GLY)(i.e.,APTS/DE and GLY/DE)were successfully synthesized via the wet chemical method for the time-and cost-efficient removal of indoor formaldehyde(HCHO).First,the optimal preparation conditions of the two composites were determined,and then their microstructures and morphologies were characterized and analyzed.Batch HCHO adsorption experiments with the two types of amino-modified DE composites were also conducted to compare their adsorption properties.Experimental results indicated that the pseudo-second-order kinetic and Langmuir isotherm models could well describe the adsorption process,and the maximum adsorption capacities of APTS/DE and GLY/DE prepared under optimal conditions at 20°C were 5.83 and 1.14 mg·g^(-1),respectively.The thermodynamic parameters of the composites indicated that the adsorption process was spontaneous and exothermic.The abundant amine groups grafted on the surface of DE were derived from the Schiff base reaction and were essential for the high-efficient adsorption performance toward HCHO.展开更多
Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical pr...Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical properties of coal gangue and coal fly ash are introduced.The mechanism and application characteristics of the pretreatment processes for zeolite synthesis from coal-based solid wastes are also introduced.The synthesis processes of coal-based solid waste zeolite and their advantages and disadvantages are summarized.Furthermore,the application characteristics of various coal-based solid waste zeolites and their common application fields are illustrated.Finally,we propose an alkaline fusion-assisted supercritical hydrothermal crystallization as an efficient method for synthesizing coal-based solid waste zeolites.In addition,more attention should be given to the recycling of alkaline waste liquid and the application of coal-based solid waste zeolites in the field of volatile organic compound adsorption removal.展开更多
基金financially supported by the Beijing Natural Science Foundation(No.2202044)the National Postdoctoral Program for Innovative Talents(No.BX20190370)+1 种基金the China Postdoctoral Science Foundation(No.2020M680757)the Fundamental Research Funds for the Central Universities(No.2020YJSHH03)。
文摘Diatomite supported nano zero valent iron(n ZVI)catalyst(NDA)with complex network structure was prepared via a mild reduction precipitation method in this work.The pore structure and pore distribution of NDA can be regulated and controlled through adjusting the loading amount of n ZVI.In general,the nano three-dimensional network formed by n ZVI and diatomite channels greatly increase the specific surface area and pore volume of NDA,and further formed more active sites,which made NDA have better performance in activating PMS to degrade BPA than pure n ZVI.The pseudo-first-order reaction rate constant of 50-NDA(50%-n ZVI/diatomite)is almost 3 times higher than that of pure n ZVI.Besides,the electron paramagnetic resonance(EPR)and radical quenching experiments showed that the activation process was dominated by the sulfate radical(SO_(4)^(-))and hydroxyl radical(·OH)produced by Fe;oxidation.The generated electrons promote the self-decomposition of PMS to produce singlet oxygen(^(1)O_(2)),and then the valence state of iron changes to produce free radicals.In addition,the possible degradation pathway of BPA was inferred from the intermediate products identified by liquid chromatograph-mass spectrometer(LC-MS).This study provides a novel strategy for the design and preparation of three-dimensional composite catalysts derived from natural mineral.
基金financially supported by the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.C201903678)the Fundamental Research Funds for the Central Universities(2020YJSHH02)+1 种基金Fok Ying Tung Education Foundation,China(No.171042)the Yue Qi Young Scholar Project of the China University of Mining and Technology(Beijing)(No.2017 QN12)。
文摘Two amino-functionalized diatomite(DE)composites modified by 3-aminopropyltriethoxysilane(APTS)or glycine(GLY)(i.e.,APTS/DE and GLY/DE)were successfully synthesized via the wet chemical method for the time-and cost-efficient removal of indoor formaldehyde(HCHO).First,the optimal preparation conditions of the two composites were determined,and then their microstructures and morphologies were characterized and analyzed.Batch HCHO adsorption experiments with the two types of amino-modified DE composites were also conducted to compare their adsorption properties.Experimental results indicated that the pseudo-second-order kinetic and Langmuir isotherm models could well describe the adsorption process,and the maximum adsorption capacities of APTS/DE and GLY/DE prepared under optimal conditions at 20°C were 5.83 and 1.14 mg·g^(-1),respectively.The thermodynamic parameters of the composites indicated that the adsorption process was spontaneous and exothermic.The abundant amine groups grafted on the surface of DE were derived from the Schiff base reaction and were essential for the high-efficient adsorption performance toward HCHO.
基金This work was financially supported by the National Key R&D Program of China(Nos.2020YFC1806504 and 2019YFC1904903)the Yue Qi Young Scholar Project,China University of Mining&Technology(Beijing)(No.2017QN12).
文摘Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical properties of coal gangue and coal fly ash are introduced.The mechanism and application characteristics of the pretreatment processes for zeolite synthesis from coal-based solid wastes are also introduced.The synthesis processes of coal-based solid waste zeolite and their advantages and disadvantages are summarized.Furthermore,the application characteristics of various coal-based solid waste zeolites and their common application fields are illustrated.Finally,we propose an alkaline fusion-assisted supercritical hydrothermal crystallization as an efficient method for synthesizing coal-based solid waste zeolites.In addition,more attention should be given to the recycling of alkaline waste liquid and the application of coal-based solid waste zeolites in the field of volatile organic compound adsorption removal.
