[Objective] The paper was to evaluate effects of peracetic acid （PAA） combined with calcium treatments on storage quality of Ioquat fruits, so as to pro- vide practical techniques to solve the problems of postharves...[Objective] The paper was to evaluate effects of peracetic acid （PAA） combined with calcium treatments on storage quality of Ioquat fruits, so as to pro- vide practical techniques to solve the problems of postharvest rot and quality deteri- oration for Ioquat fruits. [Method] With Ioquat fruits of Qingzhong variety as materi- als, 0.2%, 0.4% and 0.8% PAA combined with 0.8% CaCI2 was used to soak Ioquat fruits for 4 min, 0.8% CaCl2 and water treatments were set as two controls; the fruits were dried and packaged by 0.02 mm PE bags, then stored under non-chilling low temperature of （7±1） ℃. The indicators related to storage quality of Ioquat fruits were randomly tested once every 3 d, and their variation situations were analyzed. [Result] Compared with two control treatments and 0.2% PAA, 0.8% PAA combined with calcium treatments, the treatment of 0.4% PAA combined with 0.8% CaCl2 could significantly inhibit rot index, weight loss rate, firmness and cell membrane permeability of Ioquat fruits during storage period, which could also effectively delay the reduction of titratable acid, vitamin C, soluble solid content and juice yield, and maintain respiration intensity of fruits at a low level; the appearance and flavor qual- ity of fruits were good after stored for 25 d. [Conclusion] 0.4% PAA combined with 0.8% CaCl2 treatment is an efficient, safe and economical practice technology in an- ti-corrosion and quality preservation for postharvest Ioquat fruits .展开更多
Background Antimicrobial alternatives are urgently needed,including for poultry production systems.In this study,we tested the potential broad-range antimicrobial alternative peracetic acid,delivered in feed via the h...Background Antimicrobial alternatives are urgently needed,including for poultry production systems.In this study,we tested the potential broad-range antimicrobial alternative peracetic acid,delivered in feed via the hydrolysis of encapsulated precursors through a 28-day study using 375 Ross 308 broiler chickens.We tested two peracetic acid concentrations,30 and 80 mg/kg on birds housed on re-used litter,and we evaluated the impact of both levels on gut microbial communities,bacterial concentration,antimicrobial resistance genes relative abundance and growth performance when compared to control birds housed on either clean or re-used litter.Results Body weight gain and feed conversion ratio improved in peracetic acid fed birds.At d 28,birds given 30 mg/kg of peracetic acid had a decreased Firmicutes and an increased Proteobacteria abundance in the jejunum,accompanied by an increase in Bacillus,Flavonifractor and Rombustia in the caeca,and a decreased abundance of tetracycline resistance genes.Chicken given 80 mg/kg of peracetic acid had greater caecal abundance of macrolides lincosamides and streptogramins resistance genes.Growth performance on clean litter was reduced compared to reused litter,which concurred with increased caecal abundance of Blautia,decreased caecal abundance of Escherichia/Shigella,Anaerostipes and Jeotgalicoccus,and greater gene abundance of vancomycin,tetracycline,and macrolides resistance genes.Conclusions Peracetic acid could be used as a safe broad-spectrum antimicrobial alternative in broilers.Encapsulated precursors were able to reduce the bacterial concentration in the jejunum whilst promoting the proliferation of probiotic genera in the caeca,especially at the low peracetic acid concentrations tested,and improve growth performance.Moreover,our findings offer further insights on potential benefits of rearing birds on re-used litter,suggesting that the latter could be associated with better performance and reduced antimicrobial resistance risk compared to clean litter rearing.展开更多
Peracetic acid(PAA),known for its environmentally friendly properties as a oxidant and bactericide,is gaining prominence in decontamination and disinfection applications.The primary product of PAA oxidation is acetate...Peracetic acid(PAA),known for its environmentally friendly properties as a oxidant and bactericide,is gaining prominence in decontamination and disinfection applications.The primary product of PAA oxidation is acetate that can serve as an electron acceptor(EA)for the biosynthesis of medium-chain fatty acids(MCFAs)via chain elongation(CE)reactions.Hence,PAA-based pretreatment is supposed to be beneficial for MCFAs production from anaerobic sludge fermentation,as it could enhance organic matter availability,suppress competing microorganisms and furnish EA by providing acetate.However,such a hypothesis has rarely been proved.Here we reveal that PAA-based pretreatment leads to significant exfoliation of extracellular polymeric substances(EPS)from sludge flocs and disruption of proteinic secondary structures,through inducing highly active free radicals and singlet oxygen.The production of MCFAs increases substantially to 11,265.6 mg COD L^(-1),while the undesired byproducts,specifically long-chain alcohols(LCAs),decrease to 723.5 mg COD L^(-1).Microbial activity tests further demonstrate that PAA pretreatment stimulates the CE process,attributed to the up-regulation of functional genes involved in fatty acid biosynthesis pathway.These comprehensive findings provide insights into the effectiveness and mechanisms behind enhanced MCFAs production through PAA-based technology,advancing our understanding of sustainable resource recovery from sewage sludge.展开更多
In this paper,shorter residence time（a few minutes）with high yield in the trickle bed process for per- acetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA...In this paper,shorter residence time（a few minutes）with high yield in the trickle bed process for per- acetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA-5118.For acetaldehyde in acetone with ferric ion as catalyst,the optimized process conditions were presented. The main factors influencing the yield,selectivity and conversion are residence time,temperature and acetaldehyde concentration,respectively.The temperature range checked is from 30 to 65℃.High yield of 81.53%with high se- lectivity of 91.84%can be obtained at higher temperature of 55℃when the residence time is 5.5min and the acet- aldehyde concentration is 9.85%（by mass）.And there is a critical acetaldehyde concentration point（Cccp）between 18%and 19.5%（by mass）.At temperature less than 55℃,the highest yield to peracetic acid at each temperature level increases with temperature when the acetaldehyde concentration is below Cccp and decreases with temperature when the acetaldehyde concentration is above Cccp.展开更多
This paper has studied processing conditions and the influence of every variable to the pulp when the fluorescence in cotton linter pulp is eliminated with peracetic acid. The suitable variables of the elimination of ...This paper has studied processing conditions and the influence of every variable to the pulp when the fluorescence in cotton linter pulp is eliminated with peracetic acid. The suitable variables of the elimination of fluorescence. are found.展开更多
Based on the kinetic equations and equilibrium constants,some mathematic models were developed for calculating peracetic acid(PAA)concentration,equilibrium conversion rate of hydrogen peroxide,etc.The effects of sever...Based on the kinetic equations and equilibrium constants,some mathematic models were developed for calculating peracetic acid(PAA)concentration,equilibrium conversion rate of hydrogen peroxide,etc.The effects of several parameters on PAA synthesis were investigated by experimentation and modeling.The equilibrium constants determined from the forward and reverse rate constants at 293,303,313 and 323 K were 2.91,2.81,2.72 and 2.63,respectively.The models could predict the values of equilibrium concentration of PAA with average relative deviation of less than 10%.Both of the experimental and model-calculated results demonstrated that temperature and catalyst loading were the most important factors affecting the rate of PAA synthesis,but high temperature led to the decrease of equilibrium concentration of PAA.According to the model,the reaction could achieve equilibrium within 24 h when operated at 303 K with 1%～1.5%(ω)sulfuric acid as catalyst.Additionally,when using anhydrous acetic acid and 30%hydrogen peroxide to prepare PAA,the volumetric ratio of the two solutions should be in the range of 1.2～1.5 in order to obtain the highest equilibrium concentration of PAA.This study can serve as a step towards the further optimization of PAA synthesis and some other related investigations.展开更多
In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was ...In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was significantly increased to 99.3%in the B/Fe^(3+)/PAA system over 10 min.The B/Fe^(3+)/PAA process also exhibited superior resistance to natural substances,excellent adaptability to different harmful substances,and good removal of antibiotics in natural fresh water samples.The mechanism of action of boron for Fe^(3+)reduction was determined using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FT-IR)spectroscopy,density functional theory(DFT)calculations,and electrochemical tests.The dominant role of^(·)OH was confirmed using quenching experiments,electron spin resonance(EPR)spectroscopy,and quantitative tests.Organic radicals(R-O^(·))and Fe(IV)also significantly contribute to the removal of SMT.DFT calculations on the reaction between Fe^(2+)and the PAA were conducted to further determine the contribution from ^(·)OH,R-O^(·),and Fe(IV)from the perspective of thermodynamics and the reaction pathways.Different boron dosages,Fe^(3+)dosages,and initial pH values were also investigated in the B/Fe^(3+)/PAA system to study their effect of SMT removal and the production of the reactive species.Fe(IV)production determined the k_(R-O·+Fe(IV))value suggesting that Fe(IV)may play a more important role than R-O^(·).A comparison of the results with other processes has also proved that the procedure described in this study(B/Fe^(3+)/PAA)is an effective method for the degradation of antibiotics.展开更多
Water contamination by tetracycline(TC)has emerged as an environmental concern owing to its widespread use and antibiotic resistance.Application of peracetic acid(PAA)in the water and wastewater treatment has recently...Water contamination by tetracycline(TC)has emerged as an environmental concern owing to its widespread use and antibiotic resistance.Application of peracetic acid(PAA)in the water and wastewater treatment has recently been proposed and demonstrated to be effective for TC abatement,yet the underlying reaction kinetics between the PAA and TC are not yet clear.To explore the reaction kinetics,the effect of solution pH on TC abatement by PAA is studied and the species-specific rate constants are calculated.The ability to donate and accept electrons for different species of TC and PAA is evaluated via density functional theory(DFT)calculations.The pH-dependent apparent second-order rate constants of TC abatement by PAA exhibits the parabolic shape with the maximum at p H 8.5(9.75 L mol^(-1)s^(-1)).This phenomenon is closely related to the speciation of TC and PAA,in which the reaction between PAAH and TTC^(2-)possesses the highest species-specific rate constants according to the kinetic simulation.Further DFT calculations suggest that the HOMO of TTCH^(+),TTC,TTC^(-),TTC^(2-)and the LUMO of PAAH and PAA-are–6.40,–6.26,–5.10,–4.94 e V and–0.24,0.60 e V,respectively.According to the DFT calculations,deprotonation of TC and PAA leads to an increase of the HOMO value of TC and the LUMO value of PAA.Furthermore,the HOMOTC–LUMOPAAvalues is in good agreement with the trend of species-specific rate constants,which can be used to evaluate the reactivity between PAA and TC with different species.This study provides the kinetic data and theoretical basis for the reaction of PAA and TC,which is critical for the application of PAA in the treatment of water and wastewater.展开更多
This study innovated cobalt-based catalytic nanocomposites(CCNs)for the heterogeneous activation of peracetic acid(PAA),a green and efficient advanced oxidation process for removing antibiotics from water.Commercial C...This study innovated cobalt-based catalytic nanocomposites(CCNs)for the heterogeneous activation of peracetic acid(PAA),a green and efficient advanced oxidation process for removing antibiotics from water.Commercial Co_(3)O_(4) catalysts exhibit limited activity due to stable electronic structures.To overcome this,CCNs were synthesized using a one-step condensation method,incorporating a size control strategy that anchors Co_(3)O_(4) nanoclusters within 4‒5 nm onto six-fold cavity of g-C3N4,simultaneously modifying the coordination environment of Co.This alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial Co_(3)O_(4).The improved performance of CCN2,in particular,is attributed to a shift in the cobalt d band center towards the Fermi level,facilitating electron delocalization and transfer,enhancing Co‒O bonding,and accelerating PAA decomposition.CCN2’s superior activity,with a cefapirin(CFP)degradation kinetic rate constant(k1=0.760 min^(−1))~11 times that of PAA direct oxidation(k1=0.070 min^(−1))and~5 times that of commercial Co_(3)O_(4)/PAA system(k1=0.164 min^(−1)),is due to its ability to generate dominant reactive species for antibiotic degradation,including alkoxy radicals(CH3C(=O)OO•),high valence metal(Co^(Ⅳ)(=O)^(2+)),and singlet oxygen(^(1)O_(2)),with the latter two being crucial for the degradation process.The degradation of CFP involved three mechanisms,including direct oxidation by PAA,decarboxylation,and open-ring reactions at nitrogen sites.This research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal,leveraging the strategy of shifting the transition metal d band center.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest "Tec-hnology Research and Experimental Demonstration of Loquat Industry"(201003073)~~
文摘[Objective] The paper was to evaluate effects of peracetic acid （PAA） combined with calcium treatments on storage quality of Ioquat fruits, so as to pro- vide practical techniques to solve the problems of postharvest rot and quality deteri- oration for Ioquat fruits. [Method] With Ioquat fruits of Qingzhong variety as materi- als, 0.2%, 0.4% and 0.8% PAA combined with 0.8% CaCI2 was used to soak Ioquat fruits for 4 min, 0.8% CaCl2 and water treatments were set as two controls; the fruits were dried and packaged by 0.02 mm PE bags, then stored under non-chilling low temperature of （7±1） ℃. The indicators related to storage quality of Ioquat fruits were randomly tested once every 3 d, and their variation situations were analyzed. [Result] Compared with two control treatments and 0.2% PAA, 0.8% PAA combined with calcium treatments, the treatment of 0.4% PAA combined with 0.8% CaCl2 could significantly inhibit rot index, weight loss rate, firmness and cell membrane permeability of Ioquat fruits during storage period, which could also effectively delay the reduction of titratable acid, vitamin C, soluble solid content and juice yield, and maintain respiration intensity of fruits at a low level; the appearance and flavor qual- ity of fruits were good after stored for 25 d. [Conclusion] 0.4% PAA combined with 0.8% CaCl2 treatment is an efficient, safe and economical practice technology in an- ti-corrosion and quality preservation for postharvest Ioquat fruits .
基金funded by the UK Department of Health and Social Care as part of the Global AMR Innovation Fund(GAMRIF,Project 104990)supports early-stage innovative research in underfunded areas of antimicrobial resistance(AMR)research and development for the benefit of those in low-and middle-income countries(LMICs),who bear the greatest burden of AMR.
文摘Background Antimicrobial alternatives are urgently needed,including for poultry production systems.In this study,we tested the potential broad-range antimicrobial alternative peracetic acid,delivered in feed via the hydrolysis of encapsulated precursors through a 28-day study using 375 Ross 308 broiler chickens.We tested two peracetic acid concentrations,30 and 80 mg/kg on birds housed on re-used litter,and we evaluated the impact of both levels on gut microbial communities,bacterial concentration,antimicrobial resistance genes relative abundance and growth performance when compared to control birds housed on either clean or re-used litter.Results Body weight gain and feed conversion ratio improved in peracetic acid fed birds.At d 28,birds given 30 mg/kg of peracetic acid had a decreased Firmicutes and an increased Proteobacteria abundance in the jejunum,accompanied by an increase in Bacillus,Flavonifractor and Rombustia in the caeca,and a decreased abundance of tetracycline resistance genes.Chicken given 80 mg/kg of peracetic acid had greater caecal abundance of macrolides lincosamides and streptogramins resistance genes.Growth performance on clean litter was reduced compared to reused litter,which concurred with increased caecal abundance of Blautia,decreased caecal abundance of Escherichia/Shigella,Anaerostipes and Jeotgalicoccus,and greater gene abundance of vancomycin,tetracycline,and macrolides resistance genes.Conclusions Peracetic acid could be used as a safe broad-spectrum antimicrobial alternative in broilers.Encapsulated precursors were able to reduce the bacterial concentration in the jejunum whilst promoting the proliferation of probiotic genera in the caeca,especially at the low peracetic acid concentrations tested,and improve growth performance.Moreover,our findings offer further insights on potential benefits of rearing birds on re-used litter,suggesting that the latter could be associated with better performance and reduced antimicrobial resistance risk compared to clean litter rearing.
基金funded by the National Natural Science Foundation of China through project 52000135The first author is funded by the Shanghai Tongji Gao Tingyao Environmental Science&Technology Development Foundation.
文摘Peracetic acid(PAA),known for its environmentally friendly properties as a oxidant and bactericide,is gaining prominence in decontamination and disinfection applications.The primary product of PAA oxidation is acetate that can serve as an electron acceptor(EA)for the biosynthesis of medium-chain fatty acids(MCFAs)via chain elongation(CE)reactions.Hence,PAA-based pretreatment is supposed to be beneficial for MCFAs production from anaerobic sludge fermentation,as it could enhance organic matter availability,suppress competing microorganisms and furnish EA by providing acetate.However,such a hypothesis has rarely been proved.Here we reveal that PAA-based pretreatment leads to significant exfoliation of extracellular polymeric substances(EPS)from sludge flocs and disruption of proteinic secondary structures,through inducing highly active free radicals and singlet oxygen.The production of MCFAs increases substantially to 11,265.6 mg COD L^(-1),while the undesired byproducts,specifically long-chain alcohols(LCAs),decrease to 723.5 mg COD L^(-1).Microbial activity tests further demonstrate that PAA pretreatment stimulates the CE process,attributed to the up-regulation of functional genes involved in fatty acid biosynthesis pathway.These comprehensive findings provide insights into the effectiveness and mechanisms behind enhanced MCFAs production through PAA-based technology,advancing our understanding of sustainable resource recovery from sewage sludge.
文摘In this paper,shorter residence time（a few minutes）with high yield in the trickle bed process for per- acetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA-5118.For acetaldehyde in acetone with ferric ion as catalyst,the optimized process conditions were presented. The main factors influencing the yield,selectivity and conversion are residence time,temperature and acetaldehyde concentration,respectively.The temperature range checked is from 30 to 65℃.High yield of 81.53%with high se- lectivity of 91.84%can be obtained at higher temperature of 55℃when the residence time is 5.5min and the acet- aldehyde concentration is 9.85%（by mass）.And there is a critical acetaldehyde concentration point（Cccp）between 18%and 19.5%（by mass）.At temperature less than 55℃,the highest yield to peracetic acid at each temperature level increases with temperature when the acetaldehyde concentration is below Cccp and decreases with temperature when the acetaldehyde concentration is above Cccp.
文摘This paper has studied processing conditions and the influence of every variable to the pulp when the fluorescence in cotton linter pulp is eliminated with peracetic acid. The suitable variables of the elimination of fluorescence. are found.
基金the Shell Global Solutions International B.V.(No.0506HL04)
文摘Based on the kinetic equations and equilibrium constants,some mathematic models were developed for calculating peracetic acid(PAA)concentration,equilibrium conversion rate of hydrogen peroxide,etc.The effects of several parameters on PAA synthesis were investigated by experimentation and modeling.The equilibrium constants determined from the forward and reverse rate constants at 293,303,313 and 323 K were 2.91,2.81,2.72 and 2.63,respectively.The models could predict the values of equilibrium concentration of PAA with average relative deviation of less than 10%.Both of the experimental and model-calculated results demonstrated that temperature and catalyst loading were the most important factors affecting the rate of PAA synthesis,but high temperature led to the decrease of equilibrium concentration of PAA.According to the model,the reaction could achieve equilibrium within 24 h when operated at 303 K with 1%～1.5%(ω)sulfuric acid as catalyst.Additionally,when using anhydrous acetic acid and 30%hydrogen peroxide to prepare PAA,the volumetric ratio of the two solutions should be in the range of 1.2～1.5 in order to obtain the highest equilibrium concentration of PAA.This study can serve as a step towards the further optimization of PAA synthesis and some other related investigations.
基金supported by the Natural Science Foundation of Jiangsu Province in China (No.BK20210952)the Jiangsu Provincial Key Laboratory of Environmental Engineering (No.ZX2022002)+2 种基金the National Natural Science Foundation of China (Nos.52200095,22176102,and 21806081)the China Postdoctoral Science Foundation Project (No.2020M681552)the Natural Science Foundation of Tianjin (No.19JCQNJC07900)。
文摘In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was significantly increased to 99.3%in the B/Fe^(3+)/PAA system over 10 min.The B/Fe^(3+)/PAA process also exhibited superior resistance to natural substances,excellent adaptability to different harmful substances,and good removal of antibiotics in natural fresh water samples.The mechanism of action of boron for Fe^(3+)reduction was determined using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FT-IR)spectroscopy,density functional theory(DFT)calculations,and electrochemical tests.The dominant role of^(·)OH was confirmed using quenching experiments,electron spin resonance(EPR)spectroscopy,and quantitative tests.Organic radicals(R-O^(·))and Fe(IV)also significantly contribute to the removal of SMT.DFT calculations on the reaction between Fe^(2+)and the PAA were conducted to further determine the contribution from ^(·)OH,R-O^(·),and Fe(IV)from the perspective of thermodynamics and the reaction pathways.Different boron dosages,Fe^(3+)dosages,and initial pH values were also investigated in the B/Fe^(3+)/PAA system to study their effect of SMT removal and the production of the reactive species.Fe(IV)production determined the k_(R-O·+Fe(IV))value suggesting that Fe(IV)may play a more important role than R-O^(·).A comparison of the results with other processes has also proved that the procedure described in this study(B/Fe^(3+)/PAA)is an effective method for the degradation of antibiotics.
基金National Natural Science Foundation of China(No.52170088)Natural Science Foundation of Fujian Province(No.2022J05064)the Fundamental Research Funds for the Central Universities(No.ZQN-1118)。
文摘Water contamination by tetracycline(TC)has emerged as an environmental concern owing to its widespread use and antibiotic resistance.Application of peracetic acid(PAA)in the water and wastewater treatment has recently been proposed and demonstrated to be effective for TC abatement,yet the underlying reaction kinetics between the PAA and TC are not yet clear.To explore the reaction kinetics,the effect of solution pH on TC abatement by PAA is studied and the species-specific rate constants are calculated.The ability to donate and accept electrons for different species of TC and PAA is evaluated via density functional theory(DFT)calculations.The pH-dependent apparent second-order rate constants of TC abatement by PAA exhibits the parabolic shape with the maximum at p H 8.5(9.75 L mol^(-1)s^(-1)).This phenomenon is closely related to the speciation of TC and PAA,in which the reaction between PAAH and TTC^(2-)possesses the highest species-specific rate constants according to the kinetic simulation.Further DFT calculations suggest that the HOMO of TTCH^(+),TTC,TTC^(-),TTC^(2-)and the LUMO of PAAH and PAA-are–6.40,–6.26,–5.10,–4.94 e V and–0.24,0.60 e V,respectively.According to the DFT calculations,deprotonation of TC and PAA leads to an increase of the HOMO value of TC and the LUMO value of PAA.Furthermore,the HOMOTC–LUMOPAAvalues is in good agreement with the trend of species-specific rate constants,which can be used to evaluate the reactivity between PAA and TC with different species.This study provides the kinetic data and theoretical basis for the reaction of PAA and TC,which is critical for the application of PAA in the treatment of water and wastewater.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2021YFE010080, 2021YFA1202500, and 2023YFC3209600)the National Natural Science Foundation of China (NSFC) (Grant Nos. 52200083 and 52270053)+7 种基金Beijing Natural Science Foundation (Grant No. 8232035)Beijing Nova Program (Grant No. 20220484215)Beijing National Laboratory for Molecular Sciences (Grant No. BNLMS2023011)the Emerging Engineering Interdisciplinary-Young Scholars Project (Peking University)Horizontal Scientific Research Funds of Taiyuan University of Technology (Grant No. RH2300002821)the Science and Technology Projects of Shanxi Transportation Holdings Group Co., Ltd. (Grant No. 2022-JKKJ-8)the Fundamental Research Funds for the Central Universitiessupported by the High-Performance Computing Platform of Peking University
文摘This study innovated cobalt-based catalytic nanocomposites(CCNs)for the heterogeneous activation of peracetic acid(PAA),a green and efficient advanced oxidation process for removing antibiotics from water.Commercial Co_(3)O_(4) catalysts exhibit limited activity due to stable electronic structures.To overcome this,CCNs were synthesized using a one-step condensation method,incorporating a size control strategy that anchors Co_(3)O_(4) nanoclusters within 4‒5 nm onto six-fold cavity of g-C3N4,simultaneously modifying the coordination environment of Co.This alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial Co_(3)O_(4).The improved performance of CCN2,in particular,is attributed to a shift in the cobalt d band center towards the Fermi level,facilitating electron delocalization and transfer,enhancing Co‒O bonding,and accelerating PAA decomposition.CCN2’s superior activity,with a cefapirin(CFP)degradation kinetic rate constant(k1=0.760 min^(−1))~11 times that of PAA direct oxidation(k1=0.070 min^(−1))and~5 times that of commercial Co_(3)O_(4)/PAA system(k1=0.164 min^(−1)),is due to its ability to generate dominant reactive species for antibiotic degradation,including alkoxy radicals(CH3C(=O)OO•),high valence metal(Co^(Ⅳ)(=O)^(2+)),and singlet oxygen(^(1)O_(2)),with the latter two being crucial for the degradation process.The degradation of CFP involved three mechanisms,including direct oxidation by PAA,decarboxylation,and open-ring reactions at nitrogen sites.This research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal,leveraging the strategy of shifting the transition metal d band center.
