The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a me...The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as CuNC-20 for the activation of peroxymonosulfate(PMS)to degrade phenol(PE).Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions.The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad pH range(3-9)and demonstrated high tolerance towards coexisting ions.According to scavenger experiments and electron paramagnetic resonance analysis,singlet oxygen(^(1)O_(2))and high-valent copperoxo(Cu(Ⅲ))were the predominant reactive oxygen species,indicating that the system was nonradicaldominated during the degradation process.The quantitative structure-activity relationship(QSAR)between the oxidation rate constants of various substituted phenols and Hammett constants was established.It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant withσ^(-)correlation and exhibited a typical electrophilic reaction pattern.This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.展开更多
Nonradical oxidation has received wide attention in advanced oxidation processes for environmental remediation.Understanding the relationship between material characteristics and their ability to initiate nonradical o...Nonradical oxidation has received wide attention in advanced oxidation processes for environmental remediation.Understanding the relationship between material characteristics and their ability to initiate nonradical oxidation processes is the key to better material design and performance.Herein,a novel titanium-based metal-organic framework MIL-125-Ti/H_(2)O_(2) system was established to show a highly selective degradation efficacy toward tetracycline antibiotics.MIL-125-Ti with the abundance of TiO6 octahedra units was found to effectively activate H_(2)O_(2) under dark conditions by forming an oxidative Ti-peroxo complex.The presence of the Ti-peroxo complex,confirmed by UV-visible spectrophotometer,fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy characterizations,showed superior degradation(>95%removal rate)of oxytetracycline hydrochloride(OTC),doxycycline hydrochloride,chlortetracycline hydrochloride,and tetracycline.Density functional theory calculations were performed to assist the elucidation on the mechanism of H_(2)O_(2) activation and antibiotics degradation.The MIL-125-Ti/H_(2)O_(2) system was highly resistant to halogens and background organics,and could well maintain its original catalytic activity in actual water matrices.It retained the ability to degrade 75%of OTC within ten test cycles.This study provides new insight into the nonradical oxidation process initiated by the unique Ti-peroxo complex of Ti-based MOF.展开更多
Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS acti...Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS activation severely limit their practical applications in the degradation of organic pollutants from wastewater due to side reactions between radicals and the coexisting anions.Herein,bimetallic Fe/Mn-loaded hydroxyl-rich biochar(FeMn-OH-BC)is synthesized to activate PMS through nonradical-dominated pathways.The as-prepared FeMn-OH-BC exhibits excellent catalytic activity for degrading tetracycline at broad pH conditions ranging from 5 to 9,and about 85.0%of tetracycline is removed in 40 min.Experiments on studying the influences of various anions(HCO_(3)^(−),NO_(3)^(−),and H_(2)PO_(4)^(−))show that the inhibiting effect is negligible,suggesting that the FeMn-OHBC based PMS activation is dominated by nonradical pathways.Electron paramagnetic resonance measurements and quenching tests provide direct evidence to confirm that 1O2 is the major reactive oxygen species generated from FeMn-OH-BC based PMS activation.Theoretical calculations further reveal that the FeMn-OH sites in FeMn-OH-BC are dominant active sites for PMS activation,which have higher adsorption energy and stronger oxidative activity towards PMS than OH-BC sites.This work provides a new route for driving PMS activation by biochar-based transition metal catalysts through nonradical pathways.展开更多
Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contam...Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.展开更多
Nonradical oxidation based on peroxydisulfate(PDS)activation has attracted increasing attention for selective degradation of organic pollutants.Herein,topological defects were introduced into biochar(BC)via removing N...Nonradical oxidation based on peroxydisulfate(PDS)activation has attracted increasing attention for selective degradation of organic pollutants.Herein,topological defects were introduced into biochar(BC)via removing N atoms in N-doped BC(NBC)in an attempt to improve the nonradical catalytic performance.Compared to the pristine BC and NBC,the introduction of topological defects could achieve up to 36.6-and 8.7-times catalytic activity enhancement,respectively.More importantly,it was found that the catalytic activity was dominated by topological defects,which was verified by the significant positive correlation between the pseudo-first-order rate constants and the content of topological defects.Theoretical calculations suggested that topological defects enhanced the electrondonating ability of BC by reducing the energy gap,which made the electrons transfer to PDS molecules more easily.As a result,holes were generated after the carbon defects lost electrons,and induced a nonradical oxidation process.Benefiting from the merits of nonradical oxidation,the developed BC/PDS system showed superior performance in removing electron-rich contaminants in the presence of inorganic anions and in the actual environments.This study not only provides a potential avenue for designing efficient biochar-based catalysts,but also advances the mechanism understanding of nonradical oxidation process induced by carbon defects.展开更多
Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising m...Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.展开更多
Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targ...Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targeted contaminant in advanced oxidation processes(AOPs).Herein,we investigated the removal of HA in the alkali-activated biochar(KBC)/peroxymonosulfate(PMS)system.The modification of the original biochar(BC)resulted in an increased adsorption capacity and catalytic activity due to the introduction of more micropores,mesopores,and oxygen-containing functional groups,particularly carbonyl groups.Mechanistic insights indicated that HA is primarily chemically adsorbed on the KBC surface,while singlet oxygen(^(1)O_(2))produced by the PMS decomposition served as the major reactive species for the degradation of HA.An underlying synergistic adsorption and oxidation mechanism involving a local high concentration reaction region around the KBC interface was then proposed.This work not only provides a cost-effective solution for the elimination of HA but also advances our understanding of the nonradical oxidation at the biochar interface.展开更多
The nitrogen-doped carbon derived from graphitic carbon nitride(g-C_(3)N_(4))has been widely deployed in activating peroxymonosulfate(PMS)to remove organic pollutants.However,the instability of g-C_(3)N_(4)at high tem...The nitrogen-doped carbon derived from graphitic carbon nitride(g-C_(3)N_(4))has been widely deployed in activating peroxymonosulfate(PMS)to remove organic pollutants.However,the instability of g-C_(3)N_(4)at high temperature brings challenges to the preparation of materials.The nitrogen-doped graphitic carbon nanosheets(N-GC750)were synthesized by magnesium thermal denitrification.Magnesium undergoes the displacement reaction with small molecules produced by the pyrolysis of g-C_(3)N_(4),thereby effectively fixing carbon on the in-situ template of Mg_(3)N_(2)and avoiding direct product volatilization.N-GC750 exhibited excellent performance during the PMS activation process and bisphenol A(BPA,0.2 g/L)could be thoroughly removed in 30 min.A wide range of pH(3–11),temperature(10–40℃)and common anions were employed in studying the impact on system.Additionally,N-GC750 showed satisfactory reusability in cycle tests and promising applicability in real water samples.Quenching experiments and electron paramagnetic resonance(EPR)measurements indicated that singlet oxygen was the main active species coupled with partial electron transfer in N-GC750/PMS system.Furtherly,the oxidation products were identified,and their ecotoxicity was evaluated.This work is expected to provide a reference for the feasibility of preparing g-C_(3)N_(4)derived carbon materials and meaningful for PMS activation.展开更多
Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization...Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.展开更多
The elimination of neonicotinoids(NEOs)from water has been a research priority due to their threats to human health and ecosystems.In this study,we established the heterogeneous peroxymonosulfate(PMS)activation system...The elimination of neonicotinoids(NEOs)from water has been a research priority due to their threats to human health and ecosystems.In this study,we established the heterogeneous peroxymonosulfate(PMS)activation system using manganese catalyst(Mn NC)and cobalt catalyst(Co NC)to trigger the nonradical oxidation and synergistic oxidation pathway,respectively to remove NEOs.The results showed that the nonradical oxidation system exhibited superior NEOs degradation capability.The composition of organic pollutants in wastewater significantly impacted subsequent degradation processes.The charge distribution and reaction sites of various NEOs were analyzed using density functional theory(DFT)calculations,and it demonstrated the electron distribution and activity of NEOs were significantly influenced by the type and number of substituents.Nitro group(–NO_(2))and cyanide group(–C≡N)were identified as strong electron-withdrawing groups and prone to be attacked by negatively charged radicals.The transformation of NEOs was analyzed,and result showed that the C and N sites adjacent to the nitro group and cyanide group were more susceptible to oxidation attacks.S and N atoms,which possess strong electronegativity and high electron cloud density,were identified as key active sites in the degradation pathway.The outcomes of this study provide valuable guidance for the oriented regulation of oxidation pathways towards efficient removal of NEOs in water.展开更多
The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),whic...The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),which demonstrates superior performance in peroxymonosulfate(PMS)activation and tetracycline(TC)degradation.This system achieves a remarkable TC removal efficiency of 91.2%,significantly outperforming single-atom catalysts.Mechanistic investigations reveal that FeCo/NC induces a unique spin-state reconstruction,optimizing its electronic structure and shifting the oxidative mechanism from a radical-driven pathway to a singlet oxygen(^(1)O_(2))-dominated nonradical process.Theoretical insights from density functional theory(DFT)calculations confirm the preferred ^(1)O_(2) generation pathway at FeCo active sites,with reduced energy barriers that enhance catalytic activity.Toxicological evaluations validate that TC degradation intermediates exhibit minimal ecological risks,reinforcing the environmental safety of this approach.The long-term stability of the FeCo/NC/PMS system was evaluated via a continuous-flow photocatalytic reactor.The above results reflect the superior catalytic activity and stability of the FeCo/NC/PMS system.This work establishes a paradigm for designing advanced dual-atom catalysts and provides critical insights for developing eco-friendly solutions to antibiotic-contaminated wastewater treatment.展开更多
Reactive oxygen species(ROS)have a significant part in the elimination of recalcitrant organic pollutants and commonly coexist in one advanced oxidation system.It is difficult for us to make clear the effect of the co...Reactive oxygen species(ROS)have a significant part in the elimination of recalcitrant organic pollutants and commonly coexist in one advanced oxidation system.It is difficult for us to make clear the effect of the co-instantaneous generation of radicals and nonradicals,which would cover and obscure the transformation pathway.Herein,a coordinate welding process is presented for fabricating accessible Mn1 site catalysts(Mn SSCs)in order to clarify the nonradical(singlet oxygen/^(1)O_(2))generated pathway and transformation in oxidative removal of contaminants.The Mn SSCs achieve nearly 100%^(1)O_(2) fabrication by activating peroxymonosulfate,which displays an excellent sulfamethoxazole elimination performance,super anti-anion interference,and extraordinary stability.As revealed by density functional theory calculations,the Mn SSCs with a special welded three-dimensional nanostructure could significantly boost the activation process by oxidizing the peroxymonosulfate at the interlayer of Mn SSCs and reducing dissolved oxygen on the surface of Mn SSCs.This design of Mn SSCs with a three-dimensional welded nanostructure might offer a potential approach for employing single site catalysts for environmental remediation.展开更多
基金the financial support from Sichuan Program of Science and Technology(No.2021ZDZX0012)the National Natural Science Foundation of China(No.52200105)。
文摘The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as CuNC-20 for the activation of peroxymonosulfate(PMS)to degrade phenol(PE).Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions.The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad pH range(3-9)and demonstrated high tolerance towards coexisting ions.According to scavenger experiments and electron paramagnetic resonance analysis,singlet oxygen(^(1)O_(2))and high-valent copperoxo(Cu(Ⅲ))were the predominant reactive oxygen species,indicating that the system was nonradicaldominated during the degradation process.The quantitative structure-activity relationship(QSAR)between the oxidation rate constants of various substituted phenols and Hammett constants was established.It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant withσ^(-)correlation and exhibited a typical electrophilic reaction pattern.This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.
基金supported by the National Natural Science Foundation of China(Nos.21777116,22176150)the Fundamental Research Funds for the Central Universities。
文摘Nonradical oxidation has received wide attention in advanced oxidation processes for environmental remediation.Understanding the relationship between material characteristics and their ability to initiate nonradical oxidation processes is the key to better material design and performance.Herein,a novel titanium-based metal-organic framework MIL-125-Ti/H_(2)O_(2) system was established to show a highly selective degradation efficacy toward tetracycline antibiotics.MIL-125-Ti with the abundance of TiO6 octahedra units was found to effectively activate H_(2)O_(2) under dark conditions by forming an oxidative Ti-peroxo complex.The presence of the Ti-peroxo complex,confirmed by UV-visible spectrophotometer,fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy characterizations,showed superior degradation(>95%removal rate)of oxytetracycline hydrochloride(OTC),doxycycline hydrochloride,chlortetracycline hydrochloride,and tetracycline.Density functional theory calculations were performed to assist the elucidation on the mechanism of H_(2)O_(2) activation and antibiotics degradation.The MIL-125-Ti/H_(2)O_(2) system was highly resistant to halogens and background organics,and could well maintain its original catalytic activity in actual water matrices.It retained the ability to degrade 75%of OTC within ten test cycles.This study provides new insight into the nonradical oxidation process initiated by the unique Ti-peroxo complex of Ti-based MOF.
基金This work was financially supported by the talent starting-up project of research development fund of Zhejiang Agriculture and Forestry University(No.2034020103)the Overseas Expertise Introduction Project for Discipline Innovation(No.111 Project D18008).
文摘Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS activation severely limit their practical applications in the degradation of organic pollutants from wastewater due to side reactions between radicals and the coexisting anions.Herein,bimetallic Fe/Mn-loaded hydroxyl-rich biochar(FeMn-OH-BC)is synthesized to activate PMS through nonradical-dominated pathways.The as-prepared FeMn-OH-BC exhibits excellent catalytic activity for degrading tetracycline at broad pH conditions ranging from 5 to 9,and about 85.0%of tetracycline is removed in 40 min.Experiments on studying the influences of various anions(HCO_(3)^(−),NO_(3)^(−),and H_(2)PO_(4)^(−))show that the inhibiting effect is negligible,suggesting that the FeMn-OHBC based PMS activation is dominated by nonradical pathways.Electron paramagnetic resonance measurements and quenching tests provide direct evidence to confirm that 1O2 is the major reactive oxygen species generated from FeMn-OH-BC based PMS activation.Theoretical calculations further reveal that the FeMn-OH sites in FeMn-OH-BC are dominant active sites for PMS activation,which have higher adsorption energy and stronger oxidative activity towards PMS than OH-BC sites.This work provides a new route for driving PMS activation by biochar-based transition metal catalysts through nonradical pathways.
基金supported by the National Natural Science Foundation of China(Nos.22074137 and 21721003)the Ministry of Science and Technology of China(No.2016YFA0203203).
文摘Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.
基金National Key Research and Development Program of China(2021YFC1809204)National Natural Science Foundation of China(42192573,21621005,and U21A20163)+1 种基金Research and Development Program of Zhejiang Province,China(2021C0167)Fundamental Research Funds for the Central Universities(226-2022-00212).
文摘Nonradical oxidation based on peroxydisulfate(PDS)activation has attracted increasing attention for selective degradation of organic pollutants.Herein,topological defects were introduced into biochar(BC)via removing N atoms in N-doped BC(NBC)in an attempt to improve the nonradical catalytic performance.Compared to the pristine BC and NBC,the introduction of topological defects could achieve up to 36.6-and 8.7-times catalytic activity enhancement,respectively.More importantly,it was found that the catalytic activity was dominated by topological defects,which was verified by the significant positive correlation between the pseudo-first-order rate constants and the content of topological defects.Theoretical calculations suggested that topological defects enhanced the electrondonating ability of BC by reducing the energy gap,which made the electrons transfer to PDS molecules more easily.As a result,holes were generated after the carbon defects lost electrons,and induced a nonradical oxidation process.Benefiting from the merits of nonradical oxidation,the developed BC/PDS system showed superior performance in removing electron-rich contaminants in the presence of inorganic anions and in the actual environments.This study not only provides a potential avenue for designing efficient biochar-based catalysts,but also advances the mechanism understanding of nonradical oxidation process induced by carbon defects.
基金supported by the National Key Research and Development Program of China(No.2021YFC3200700)the National Natural Science Foundation of China(No.52400010)+1 种基金the Science and Technology Commission of Shanghai Municipality(No.24ZR1472300)the Fundamental Research Funds for the Central Universities.
文摘Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.
基金supported by the National Natural Science Foundation of China(No.52200049)the China Postdoctoral Science Foundation(No.2022TQ0089)the Heilongjiang Province Postdoctoral Science Foundation(No.LBHZ22181).
文摘Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targeted contaminant in advanced oxidation processes(AOPs).Herein,we investigated the removal of HA in the alkali-activated biochar(KBC)/peroxymonosulfate(PMS)system.The modification of the original biochar(BC)resulted in an increased adsorption capacity and catalytic activity due to the introduction of more micropores,mesopores,and oxygen-containing functional groups,particularly carbonyl groups.Mechanistic insights indicated that HA is primarily chemically adsorbed on the KBC surface,while singlet oxygen(^(1)O_(2))produced by the PMS decomposition served as the major reactive species for the degradation of HA.An underlying synergistic adsorption and oxidation mechanism involving a local high concentration reaction region around the KBC interface was then proposed.This work not only provides a cost-effective solution for the elimination of HA but also advances our understanding of the nonradical oxidation at the biochar interface.
基金the Science and Technology Commission of Shanghai Municipality(Nos.21ZR1425200,18020500800,18JC1412900 and 19DZ2271100)。
文摘The nitrogen-doped carbon derived from graphitic carbon nitride(g-C_(3)N_(4))has been widely deployed in activating peroxymonosulfate(PMS)to remove organic pollutants.However,the instability of g-C_(3)N_(4)at high temperature brings challenges to the preparation of materials.The nitrogen-doped graphitic carbon nanosheets(N-GC750)were synthesized by magnesium thermal denitrification.Magnesium undergoes the displacement reaction with small molecules produced by the pyrolysis of g-C_(3)N_(4),thereby effectively fixing carbon on the in-situ template of Mg_(3)N_(2)and avoiding direct product volatilization.N-GC750 exhibited excellent performance during the PMS activation process and bisphenol A(BPA,0.2 g/L)could be thoroughly removed in 30 min.A wide range of pH(3–11),temperature(10–40℃)and common anions were employed in studying the impact on system.Additionally,N-GC750 showed satisfactory reusability in cycle tests and promising applicability in real water samples.Quenching experiments and electron paramagnetic resonance(EPR)measurements indicated that singlet oxygen was the main active species coupled with partial electron transfer in N-GC750/PMS system.Furtherly,the oxidation products were identified,and their ecotoxicity was evaluated.This work is expected to provide a reference for the feasibility of preparing g-C_(3)N_(4)derived carbon materials and meaningful for PMS activation.
基金financially supported by the GuangDong Basic and Applied Basic Research Foundation(Nos.2019A1515110649,2020A1515110271,2019A1515110244)the National Natural,Science Fund of China(No.51908127)+1 种基金the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)the Research Team in Dongguan University of Technology(No.TDYB2019013)。
文摘Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.
基金funded by National Natural Science Foundation of China(No.42177382)。
文摘The elimination of neonicotinoids(NEOs)from water has been a research priority due to their threats to human health and ecosystems.In this study,we established the heterogeneous peroxymonosulfate(PMS)activation system using manganese catalyst(Mn NC)and cobalt catalyst(Co NC)to trigger the nonradical oxidation and synergistic oxidation pathway,respectively to remove NEOs.The results showed that the nonradical oxidation system exhibited superior NEOs degradation capability.The composition of organic pollutants in wastewater significantly impacted subsequent degradation processes.The charge distribution and reaction sites of various NEOs were analyzed using density functional theory(DFT)calculations,and it demonstrated the electron distribution and activity of NEOs were significantly influenced by the type and number of substituents.Nitro group(–NO_(2))and cyanide group(–C≡N)were identified as strong electron-withdrawing groups and prone to be attacked by negatively charged radicals.The transformation of NEOs was analyzed,and result showed that the C and N sites adjacent to the nitro group and cyanide group were more susceptible to oxidation attacks.S and N atoms,which possess strong electronegativity and high electron cloud density,were identified as key active sites in the degradation pathway.The outcomes of this study provide valuable guidance for the oriented regulation of oxidation pathways towards efficient removal of NEOs in water.
基金supported by the Yunnan Province Education Department Scientific Research Fund Project(No.2024J0828)the Basic Research Project of Yunnan Province Science and Technology Department(No.202201AU070004)the National Natural Science Foundation of China(Nos.52272287 and 22268003).
文摘The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),which demonstrates superior performance in peroxymonosulfate(PMS)activation and tetracycline(TC)degradation.This system achieves a remarkable TC removal efficiency of 91.2%,significantly outperforming single-atom catalysts.Mechanistic investigations reveal that FeCo/NC induces a unique spin-state reconstruction,optimizing its electronic structure and shifting the oxidative mechanism from a radical-driven pathway to a singlet oxygen(^(1)O_(2))-dominated nonradical process.Theoretical insights from density functional theory(DFT)calculations confirm the preferred ^(1)O_(2) generation pathway at FeCo active sites,with reduced energy barriers that enhance catalytic activity.Toxicological evaluations validate that TC degradation intermediates exhibit minimal ecological risks,reinforcing the environmental safety of this approach.The long-term stability of the FeCo/NC/PMS system was evaluated via a continuous-flow photocatalytic reactor.The above results reflect the superior catalytic activity and stability of the FeCo/NC/PMS system.This work establishes a paradigm for designing advanced dual-atom catalysts and provides critical insights for developing eco-friendly solutions to antibiotic-contaminated wastewater treatment.
基金supported by the National Natural Science Foundation of China (22176060)Shanghai Municipal Science and Technology Major Project (2018SHZDZX03)+3 种基金the Program of Introducing Talents of Discipline to Universities (B16017)Science and Technology Commission of Shanghai Municipality (20DZ2250400)Shanghai Sailing Program (20YF1410600)the Fundamental Research Funds for the Central Universities (222201717003)。
基金supported by China Ministry of Science and Technology(2021YFA1500404)the Anhui Provincial Natural Science Foundation(2108085QB70,2108085UD06)+2 种基金the Collaborative Innovation Program of Hefei Science Center,CAS(2021HSC-CIP002)the Natural Science Foundation of Hefei,China(Grant No.2021044)the Fundamental Research Funds for the Central Universities(WK2060000004,WK2060000021,WK2060000025,KY2060000180,and KY2060000195).
文摘Reactive oxygen species(ROS)have a significant part in the elimination of recalcitrant organic pollutants and commonly coexist in one advanced oxidation system.It is difficult for us to make clear the effect of the co-instantaneous generation of radicals and nonradicals,which would cover and obscure the transformation pathway.Herein,a coordinate welding process is presented for fabricating accessible Mn1 site catalysts(Mn SSCs)in order to clarify the nonradical(singlet oxygen/^(1)O_(2))generated pathway and transformation in oxidative removal of contaminants.The Mn SSCs achieve nearly 100%^(1)O_(2) fabrication by activating peroxymonosulfate,which displays an excellent sulfamethoxazole elimination performance,super anti-anion interference,and extraordinary stability.As revealed by density functional theory calculations,the Mn SSCs with a special welded three-dimensional nanostructure could significantly boost the activation process by oxidizing the peroxymonosulfate at the interlayer of Mn SSCs and reducing dissolved oxygen on the surface of Mn SSCs.This design of Mn SSCs with a three-dimensional welded nanostructure might offer a potential approach for employing single site catalysts for environmental remediation.
