O-sulfation is a vital post-translational modification,where the primary objective is to identify an efficient and straightforward sulfonate donor for this transformation.Persulfate salts,as commercial available and l...O-sulfation is a vital post-translational modification,where the primary objective is to identify an efficient and straightforward sulfonate donor for this transformation.Persulfate salts,as commercial available and low-toxicity inorganic oxidants,are ideal sources for O-sulfation;however,they usually participate in electron transfer reactions and do not readily engage in group-transfer transformations.Here,we present an efficient and practical O-sulfation method for alcohols and oximes using K_(2)S_(2)O_(8) and N,N-dimethylformamide.The modular control over the versatile oxidative properties of persulfates,along with their role as sulfate sources,introduces a novel SO_(3) donor in the O-sulfation process,enabling its utility in latestage functionalization of drug molecules and natural products.展开更多
Metal-organic frameworks(MOFs)and their derivatives have gained significant attention in recent years for their ability to catalyze the advanced oxidation of persulfates.Cerium-doped MOFs,in particular,have shown prom...Metal-organic frameworks(MOFs)and their derivatives have gained significant attention in recent years for their ability to catalyze the advanced oxidation of persulfates.Cerium-doped MOFs,in particular,have shown promise due to their high catalytic efficiency,practical applicability,and cost-effectiveness.However,their structure,catalytic properties,and mechanisms are not yet fully understood.ZIF-8 was chosen as the raw material to prepare cerium-doped hollow carbon nano fibers(Ce-HCNFs)using the electrostatic spinning-calcination method.The objective is to investigate the structure,catalytic performance,and catalytic mechanism of Ce-HCNFs.The results show that Ce-HCNFs catalyzed the degradation of tetracycline(TC)by persulfate up to 76.9%,Quenching experiments and electron paramagnetic resonance experiments indicate the dominant role of single-linear oxygen.Furthermore,the experiments on the influence factor and cycling demonstrate the exceptional stability and recycling capability of Ce-HCNFs in real-world water environments.展开更多
Catalytic oxidation of organic pollutants is a well-known and effective technique for pollutant abatement.Unfortunately,this method is significantly hindered in practical applications by the lowefficiency and difficul...Catalytic oxidation of organic pollutants is a well-known and effective technique for pollutant abatement.Unfortunately,this method is significantly hindered in practical applications by the lowefficiency and difficult recovery of the catalysts in a powdery form.Herein,a three-dimensional(3D)framework of Fe-incorporated Ni_(3)S_(2)nanosheets in-situ grown on Ni foam(Fe-Ni_(3)S_(2)@NF)was fabricated by a facile two-step hydrothermal process and applied to trigger peroxymonosulfate(PMS)oxidation of organic compounds inwater.A homogeneous growth environment enabled the uniform and scalable growth of Fe-Ni_(3)S_(2)nanosheets on the Ni foam.Fe-Ni_(3)S_(2)@NF possessed outstanding activity and durability in activating PMS,as it effectively facilitated electron transfer from organic pollutants to PMS.Fe-Ni_(3)S_(2)@NF initially supplied electrons to PMS,causing the catalyst to undergo oxidation,and subsequently accepted electrons from organic compounds,returning to its initial state.The introduction of Fe into the Ni_(3)S_(2)lattice enhanced electrical conductivity,promoting mediated electron transfer between PMS and organic compounds.The 3D conductive Ni foam provided an ideal platform for the nucleation and growth of Fe-Ni_(3)S_(2),accelerating pollutant abatement due to its porous structure and high conductivity.Furthermore,its monolithic nature simplified the catalyst recycling process.A continuous flow packed-bed reactor by encapsulating Fe-Ni_(3)S_(2)@NF catalyst achieved complete pollutant abatement with continuous operation for 240 h,highlighting its immense potential for practical environmental remediation.This study presents a facile synthesis method for creating a novel type of monolithic catalyst with high activity and durability for decontamination through Fenton-like processes.展开更多
In recent years,numer-ous single-atom catalysts(SACs)have been synthesized to activate persulfate(PS)by a non-radical pathway because of its high se-lectivity,and activity for the cata-lyst.Metal-nitrogen-carbon(M-N_(...In recent years,numer-ous single-atom catalysts(SACs)have been synthesized to activate persulfate(PS)by a non-radical pathway because of its high se-lectivity,and activity for the cata-lyst.Metal-nitrogen-carbon(M-N_(x)-C)has been identified as the key active site in SACs.Although methods for preparing SACs have been extensively reported,a systematic summary of the direct construction of M-N_(x)-C,espe-cially unconventional metal-nitrogen-carbon(UM-N_(x)-C,x≠4),on SACs for PS non-radical activation has still not been reported.The role of the M-N_(x)-C active sites on PS non-radical activation is discussed and methods for the formation of M-N_(x)-C and UM-N_(x)-C active sites in SACs and the effect of catalyst carriers such as carbon nitride(g-C_(3)N_(4)),MOFs,COFs,and other car-bon materials are reviewed.Direct and indirect methods,especially for UM-N_(x)-C active site formation,are also elaborated.Factors affecting the formation of a M-N_(x)-C active site on SACs are also discussed.Prospects for the use of M-N_(x)-C active sites for the non-radical activation of PS by SACs to remove organic contaminants from wastewater are evaluated.展开更多
In this study,layered chitosan-based magnetic nickel ferrite NiFe_(2)O_(4)/chitosan(CS-LDO)composites were synthesized.The results show that under optimal conditions,98%of methylene blue(MB)and 92%of xylenol orange(XO...In this study,layered chitosan-based magnetic nickel ferrite NiFe_(2)O_(4)/chitosan(CS-LDO)composites were synthesized.The results show that under optimal conditions,98%of methylene blue(MB)and 92%of xylenol orange(XO)can be simultaneously degraded within 120 min in the CS-LDO/persulfate(PS)system,and the removal rates of total organic carbon(TOC)and chemical oxygen demand(COD)can reach 67.32%and 74.23%,respectively.In addition,the strong magnetism of the material itself and multiple cycle experiments indicate that CS-LDO has good recyclability and reusability.The results of quenching experiments,electron paramagnetic resonance(EPR)and electrochemical characterization tests demonstrate that the degradation occurred via both radical and non-radical mechanisms.The differing types of reactive oxygen species(ROS)acting and the different electrostatic attraction between the materials and the two dyes lead to a significant difference in the removal effect of two dyes.The degradation mechanism is the redox reaction between Ni^(2+)/Ni^(3+),Fe^(2+)/Fe^(3+)and the synergistic effect of Ni^(3+)/Fe^(2+).Finally,the biotoxicity assessment demonstrated that both the degradation intermediates of mixed dyes and the material itself exhibited low biotoxicity.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 oxidation characteristics of sulfite and thiosulfate were examined by using thermodynamic calculations and simulated desulfurization solution experiments to investigate their difference.Subsequently,a new multista...The oxidation characteristics of sulfite and thiosulfate were examined by using thermodynamic calculations and simulated desulfurization solution experiments to investigate their difference.Subsequently,a new multistage oxidation method using oxygen−ammonium persulfate was presented and applied to the oxidation of a real desulfurization solution.The results show that the concentrations of thiosulfate and sulfite in the real desulfurization solution decrease from 48.76 and 61.76 g/L to 2.24 and 0.02 g/L,respectively,and the ammonium sulfate products obtained are white with uniform particles.In addition,compared with ammonium persulfate alone,the multistage oxidation method can reduce the ammonium persulfate addition by 37.56%and treatment cost by 28.13%.展开更多
Modified activated carbons(AS)were fabricated through the oxidation effect of ammonium persulfate and applied to the dynamic adsorption of different acrylate gas.The pore structures,surface chemical properties and sur...Modified activated carbons(AS)were fabricated through the oxidation effect of ammonium persulfate and applied to the dynamic adsorption of different acrylate gas.The pore structures,surface chemical properties and surface morphology of AS were respectively characterized by N2 adsorption,Boehm titration,X-ray Photoelectron Spectroscopy(XPS)and scanning electron microscopy(SEM)techniques.After modification,the specific surface area increased from 954 to 1154 m^(2)·g^(-1).The contents of oxygen-containing functional groups on the AS surface increase obviously and have a great effect on the adsorption behavior of acrylate gases.According to the results of dynamic adsorption,the adsorption capacities of acrylates are as the following order:methyl acrylate(461.9 mg·g^(-1))>methyl methacrylate(436.9 mg·g^(-1))>butyl acrylate(381.8 mg·g^(-1)),which is attributed to the size adaptability of AS pores and acrylates.The adsorption behavior of AS for acrylate gases conforms to the Bangham model and the Temkin model.展开更多
Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-r...Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-ray Diffraction(XRD)were used to characterize the morphology and phase composition of these materials.A series of batch experiments were then conducted to inves-tigate the performance and influencing factors of GO-nZVI activating peroxydisulfate(SPS)for the degra-dation of 1,2,3-trichloropropane(TCP).Finally,an in-situ oxidation reaction zone was created by GO-nZVI-activated SPS in a one-dimensional simulated system to study the remediation of TCP contamination under different aquifer conditions.The results showed that the GO-nZVI composite exhibited a porous,fluffy structure,with spherical nZVI particles loaded onto the surface and folds of the GO sheets.Compared with unmodified nZVI particles,the GO-nZVI composite significantly enhanced the removal efficiency of TCP by activated SPS,achieving a removal rate of 67.2%within an hour-78.2%higher than that of the unmodi-fied system.The SPS dosage and the C/Fe ratio in GO-nZVI were found to significantly affect the degradation efficiency of TCP.The removal rate of TCP increased with higher SPS concentration,and a 10%carbon addition,yielded the best activation effect.The one-dimensional simulation results indicated that the removal rate of TCP ranged from 30.1%to 73.3%under different conditions.A larger medium particle size and higher concentrations of reactants(SPS and GO-nZVI)improved pollutant degradation efficiency,increasing TCP removal by 62.1%,23.8%,and 3.7%,respectively.In contrast,a higher groundwater flow velocity was not conducive to the removal of pollutants,with the TCP removal rate decreasing by approxi-mately 41.9%.展开更多
A clean and efficient process for the direct extraction of valuable metals from low-grade nickel sulfide ore through oxidative leaching with(NH_(4))_(2)S_(2)O_(8)under atmosphere pressure was proposed to address the g...A clean and efficient process for the direct extraction of valuable metals from low-grade nickel sulfide ore through oxidative leaching with(NH_(4))_(2)S_(2)O_(8)under atmosphere pressure was proposed to address the growing demand for nickel and cobalt in the new energy industry.The effects of four key parameters on the metal leaching rates were systematically investigated.Characterization techniques,including XRD,SEM and EDS,were employed to analyze phase transformations during the leaching process.Under optimized conditions,approximately 96.5%of nickel,95.5%of cobalt and 65.2%of copper were successfully extracted.The kinetics of the leaching process was explored to identify the controlling mechanisms of nickel,cobalt and copper dissolution,establishing activation energies and kinetic equations for each metal.The cleanliness and efficiency of this method were confirmed through comparisons with other extraction processes for nickel sulfide ore.展开更多
Sulfamethoxazole(SMZ)is a prevalent and recalcitrant micropollutant in water,posing a significant threat to both aquatic organisms and human health.Therefore,investigating the removal of SMZ is of critical importance....Sulfamethoxazole(SMZ)is a prevalent and recalcitrant micropollutant in water,posing a significant threat to both aquatic organisms and human health.Therefore,investigating the removal of SMZ is of critical importance.In order to investigate the effect of rare earth metal doping on the performance of activated persulfate oxidative degradation of SMZ,BiFeO_(3)with different Ce doping amounts was successfully prepared by a hydrothermal method.Then,it was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),scanning transmission electro n microscopy(STEM)and Brunauer-Emmett-Teller(BET)method.The performance of porous Ce/BiFeO_(3)in the catalytic activation of persulfate(PMS)for the degradation of SMZ in water was investigated using SMZ solution as a simulated wastewater.The impact of Ce doping rate,catalyst dosage,temperature variations,common anions,natural organic matter,and PMS concentration on SMZ removal was systematically evaluated.The characterization results show that the octahedral rhombic structure of Ce can be observed on the surface of this doped catalyst,and Ce doping does not change the crystalline shape of Ce/BiFeO_(3).The specific surface area of the doped catalyst increases,accompanied by an enlargement of pore size,thereby enhancing the catalyst's adsorption capacity and resistance to contamination by SMZ.Under the optimal conditions of 25℃,SMZ concentration of 20 mg/L,0.8 g/L PMS and 0.3 g/L 0.05Ce/BiFeO_(3)catalyst,the removal rate of SMZ reaches approximately 95%within35 min of reaction time.Even after five cycles of reuse,the degradation rate of SMZ remains above 88%,demonstrating the catalyst's good stability and reusability.Bursting experiments show that SO_(4)^(·-),·OH,1O_(2)and O_(2)^(·-)are involved in the catalytic degradation process,with 1O_(2)playing a dominant role.展开更多
Persulfate(PS)is a widely used oxidant for the chemical oxidation of organic pollutants.The accurate measurement of PS concentration is crucial for the practical application process.The iodometry is the most recommend...Persulfate(PS)is a widely used oxidant for the chemical oxidation of organic pollutants.The accurate measurement of PS concentration is crucial for the practical application process.The iodometry is the most recommended method for PS determination,and its principle is based on the redox reaction between S_(2)O_(8)^(2−)and iodide ions.However,hydrogen peroxide(H_(2)O_(2)),an important intermediate product in the process of PS use,often leads to abnormally high determination concentrations of PS.Given this,a novel method was developed for the determination of PS based on the principle of the oxidation of chloride ion(Cl^(−)).The concentration of PS is calculated according to the consumption of Cl^(−)concentration,which is not disturbed by H_(2)O_(2).The optimized test conditions were explored as:C(H^(+))=2 mol/L,T=80◦C,C(Cl^(−)):C(PS)=4:1 and t=30 min.Under the optimized conditions,the limit of detection and the limit of quantification of PS concentration determined by this method were 0.26 and 0.85 g/L,respectively.And the linear range of the PS determination was 1–100 g/L with an error of 0.53%-12.06%.The spike recovery rate for determining PS concentration in the actual wastewater ranged from 94.07%-109.52%.Interfering factors such as H_(2)O_(2),Fe^(3+),MnO_(2)and natural organic matter had almost no effect on the results.This method could not only accurately determine the concentration of PS in industrial wastewater,but also determine the purity of PS industrial products.展开更多
Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water d...Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water deteriorates the distillate quality,threatening human health.Herein,we constructed a carbonbased bimetallic(C/FeCo)photothermal membrane by electrospinning technique.Results illustrated that the membrane can catalytically degrade VOCs during SIE with persulfate(PDS)mediation.PDS,as well as phenol,was mainly reacted on the interface of the photothermal membrane instead of in the bulk solution.The interception efficiency of phenol achieved nearly 100%using the C/FeCo membrane during SIE.Hydroxyl radical(•OH),sulfate radical(SO_(4)•−),superoxide radical(O_(2)•−),and singlet oxygen(^(1)O_(2))were identified as the main active substances to degrade VOCs.We also conducted SIE experiments using actual river water to evaluate the practical performance of the C/FeCo membrane.This work holds the promise of VOCs interception during SIE and enlarges the application of solar distillation in water/wastewater treatment.展开更多
It has been challenging for Fe(Ⅲ)regeneration in Fe-based photocatalysts for continuous peroxydisulfate(PDS)activation due to the lower ability to reduce Fe(Ⅲ).In this work,Fe-doped ultrathin VO_(2)(Fe-VO_(2))nanobe...It has been challenging for Fe(Ⅲ)regeneration in Fe-based photocatalysts for continuous peroxydisulfate(PDS)activation due to the lower ability to reduce Fe(Ⅲ).In this work,Fe-doped ultrathin VO_(2)(Fe-VO_(2))nanobelts were synthesized for purifying metronidazole(MNZ)via PDS activation.As an efficient Fentonlike catalyst for PDS activation,2 wt%Fe-doped VO_(2)can remove 98%of MNZ within 40 min and exhibits impressive recyclability.The synergistic effect of Fe-VO_(2)and Fe(Ⅲ)activated PDS boosted the photocatalytic performance.Moreover,SO_(4)•^(−),h+,O_(2)•^(−),^(1)O_(2),and•OH were the main reactive radicals.The effects of initial MNZ concentration,Fe-VO_(2),PDS dosage,and various anions/cations on MNZ removal by the Fe-VO_(2)/PDS/Vis system were studied.The intermediates of MNZ degradation and possible pathways were determined by density function theory(DFT)calculations and HPLC-MS.This study provided a sustainable technology using Fe-doped ultrathin VO_(2)nanobelts for photocatalytic PDS activation and decontamination of pharmaceutical wastewater.展开更多
This study comprehensively investigates the degradation performance and mechanism of environmental persistent pollutants(EPs)by combining experimental and theoretical calculations with dielectric barrier discharge(DBD...This study comprehensively investigates the degradation performance and mechanism of environmental persistent pollutants(EPs)by combining experimental and theoretical calculations with dielectric barrier discharge(DBD)plasma synergized with persulfate.The findings demonstrated that DBD plasma could generate reactive radicals,including·OH,^(1)O_(2) and·O_(2)^(-),which primarily activate persulfate through OH and·O_(2)^(-)to produce the potent oxidizing radical SO_4^(-).This process facilitated enhanced degradation and mineralization of MeP wastewater.The performance of DBD/persulfute(PS)in degrading MeP was evaluated by kinetics,energy efficiency,and co-factor calculations,combined with degradation under different influencing factors.The actives in the system were analyzed by free radical scavenging assays and UV spectrophotometric testing to determine their effects.The findings indicated that persulfate was effectively activated by DBD plasma and that·O_(2)^(-)played a significant role.The presence of persulfate elevated the levels of H_(2)O_(2) and O_(3) in the solution.The intermediates formed during the degradation of MeP were detected using LC-MS and then analyzed alongside density-functional theory(DFT)chemical predictions to anticipate the reactive sites and deduce the potential degradation pathways of methylparaben(MeP).Toxicity evaluation software confirmed that the PS/DBD system reduces acute and developmental toxicity in the water column.The study showed that DBD plasma-activated persulfate was successful in addre ssing newly identified contaminants.展开更多
To gain insight into the fine interfacial control mechanism exhibited by oxidant-coated Al powder to improve combustion performance,we prepared Al/AP and Al@AP composite fuels using ball milling and spray-drying techn...To gain insight into the fine interfacial control mechanism exhibited by oxidant-coated Al powder to improve combustion performance,we prepared Al/AP and Al@AP composite fuels using ball milling and spray-drying technology.The thermal reaction characteristics,AP decomposition behavior,and decomposition reaction pathways of Al/AP and Al@AP composite fuels were investigated using thermal analysis and Ab Initio Molecular Dynamics(AIMD)calculations.Under the influence of fine interfacial control,the low-temperature decomposition heat release peak of AP was delayed by 25.5℃,while the high-temperature decomposition peak was advanced by 36.2℃,leading to an increase in the decomposition heat release of AP from 410.7 J/g to 1068.7 J/g.Compared to the unclad structure,the apparent activation energy of AP in low-temperature decomposition increased,and slightly decreased during high-temperature decomposition in the Al@AP composite fuel.The physical model of AP decomposition shifted to the model with higher degrees of freedom and a faster diffusion rate,characterized by rapid bidirectional diffusion at the interface.Furthermore,due to fine interfacial control,the oxidation reaction pathway of Al has been altered,changing from the final products of AP decomposition(O_(2),Cl2,etc.)to the direct oxidation of AP decomposition intermediates(HClO,ClO_(2),etc.).This accelerated and strengthened the oxidation reaction process of Al.As a result of these performance improvements,the final combustion temperature of Al@AP in the Microcanonical Ensemble(NVE)system stabilized at 2370 K,which is significantly higher than 1400 K observed for Al/AP,indicating enhanced ignition and combustion performance.展开更多
The flotabilities of chalcopyrite and galena with sodium humate（HA） and ammonium persulfate（APS） as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single...The flotabilities of chalcopyrite and galena with sodium humate（HA） and ammonium persulfate（APS） as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO_4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.展开更多
The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentratio...The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.展开更多
The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, s...The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1-（1-a）^1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed.展开更多
An efficient and practical methods for the synthesis of carbamoyl quinoline-2,4-diones via the reaction of ortho-cyanoarylacrylamides with oxamic acids was described.This cyclic reaction could be performed efficiently...An efficient and practical methods for the synthesis of carbamoyl quinoline-2,4-diones via the reaction of ortho-cyanoarylacrylamides with oxamic acids was described.This cyclic reaction could be performed efficiently under metal free conditions.Various products with functional groups could be obtained with moderate to high yields via radical mechanism.展开更多
基金supported by the National Natural Science Foundation of China(grant no.22001067)the Natural Science Foundation of Hunan Province(grant no.2023JJ40125).
文摘O-sulfation is a vital post-translational modification,where the primary objective is to identify an efficient and straightforward sulfonate donor for this transformation.Persulfate salts,as commercial available and low-toxicity inorganic oxidants,are ideal sources for O-sulfation;however,they usually participate in electron transfer reactions and do not readily engage in group-transfer transformations.Here,we present an efficient and practical O-sulfation method for alcohols and oximes using K_(2)S_(2)O_(8) and N,N-dimethylformamide.The modular control over the versatile oxidative properties of persulfates,along with their role as sulfate sources,introduces a novel SO_(3) donor in the O-sulfation process,enabling its utility in latestage functionalization of drug molecules and natural products.
基金Project supported by the National Natural Science Foundation of China(22206080)the Natural Science Foundation of Jiangsu(SBK2022041070)+1 种基金the Science and Technology Project of Henan Province(232102321050,232102321035)the International Science,Innovators,Technology Cooperation Projects of Henan Province(232102521009)。
文摘Metal-organic frameworks(MOFs)and their derivatives have gained significant attention in recent years for their ability to catalyze the advanced oxidation of persulfates.Cerium-doped MOFs,in particular,have shown promise due to their high catalytic efficiency,practical applicability,and cost-effectiveness.However,their structure,catalytic properties,and mechanisms are not yet fully understood.ZIF-8 was chosen as the raw material to prepare cerium-doped hollow carbon nano fibers(Ce-HCNFs)using the electrostatic spinning-calcination method.The objective is to investigate the structure,catalytic performance,and catalytic mechanism of Ce-HCNFs.The results show that Ce-HCNFs catalyzed the degradation of tetracycline(TC)by persulfate up to 76.9%,Quenching experiments and electron paramagnetic resonance experiments indicate the dominant role of single-linear oxygen.Furthermore,the experiments on the influence factor and cycling demonstrate the exceptional stability and recycling capability of Ce-HCNFs in real-world water environments.
基金supported by the National Natural Science Foundation of China(No.21876039)Y.Yao acknowledges the scholarship support from the China Scholarship Council(No.202106695010)Partial support from the Australian Research Council for DP230102406 is also acknowledged.
文摘Catalytic oxidation of organic pollutants is a well-known and effective technique for pollutant abatement.Unfortunately,this method is significantly hindered in practical applications by the lowefficiency and difficult recovery of the catalysts in a powdery form.Herein,a three-dimensional(3D)framework of Fe-incorporated Ni_(3)S_(2)nanosheets in-situ grown on Ni foam(Fe-Ni_(3)S_(2)@NF)was fabricated by a facile two-step hydrothermal process and applied to trigger peroxymonosulfate(PMS)oxidation of organic compounds inwater.A homogeneous growth environment enabled the uniform and scalable growth of Fe-Ni_(3)S_(2)nanosheets on the Ni foam.Fe-Ni_(3)S_(2)@NF possessed outstanding activity and durability in activating PMS,as it effectively facilitated electron transfer from organic pollutants to PMS.Fe-Ni_(3)S_(2)@NF initially supplied electrons to PMS,causing the catalyst to undergo oxidation,and subsequently accepted electrons from organic compounds,returning to its initial state.The introduction of Fe into the Ni_(3)S_(2)lattice enhanced electrical conductivity,promoting mediated electron transfer between PMS and organic compounds.The 3D conductive Ni foam provided an ideal platform for the nucleation and growth of Fe-Ni_(3)S_(2),accelerating pollutant abatement due to its porous structure and high conductivity.Furthermore,its monolithic nature simplified the catalyst recycling process.A continuous flow packed-bed reactor by encapsulating Fe-Ni_(3)S_(2)@NF catalyst achieved complete pollutant abatement with continuous operation for 240 h,highlighting its immense potential for practical environmental remediation.This study presents a facile synthesis method for creating a novel type of monolithic catalyst with high activity and durability for decontamination through Fenton-like processes.
文摘In recent years,numer-ous single-atom catalysts(SACs)have been synthesized to activate persulfate(PS)by a non-radical pathway because of its high se-lectivity,and activity for the cata-lyst.Metal-nitrogen-carbon(M-N_(x)-C)has been identified as the key active site in SACs.Although methods for preparing SACs have been extensively reported,a systematic summary of the direct construction of M-N_(x)-C,espe-cially unconventional metal-nitrogen-carbon(UM-N_(x)-C,x≠4),on SACs for PS non-radical activation has still not been reported.The role of the M-N_(x)-C active sites on PS non-radical activation is discussed and methods for the formation of M-N_(x)-C and UM-N_(x)-C active sites in SACs and the effect of catalyst carriers such as carbon nitride(g-C_(3)N_(4)),MOFs,COFs,and other car-bon materials are reviewed.Direct and indirect methods,especially for UM-N_(x)-C active site formation,are also elaborated.Factors affecting the formation of a M-N_(x)-C active site on SACs are also discussed.Prospects for the use of M-N_(x)-C active sites for the non-radical activation of PS by SACs to remove organic contaminants from wastewater are evaluated.
基金supported by the Fundamental Research Program of Shanxi Province(No.202103021224083).
文摘In this study,layered chitosan-based magnetic nickel ferrite NiFe_(2)O_(4)/chitosan(CS-LDO)composites were synthesized.The results show that under optimal conditions,98%of methylene blue(MB)and 92%of xylenol orange(XO)can be simultaneously degraded within 120 min in the CS-LDO/persulfate(PS)system,and the removal rates of total organic carbon(TOC)and chemical oxygen demand(COD)can reach 67.32%and 74.23%,respectively.In addition,the strong magnetism of the material itself and multiple cycle experiments indicate that CS-LDO has good recyclability and reusability.The results of quenching experiments,electron paramagnetic resonance(EPR)and electrochemical characterization tests demonstrate that the degradation occurred via both radical and non-radical mechanisms.The differing types of reactive oxygen species(ROS)acting and the different electrostatic attraction between the materials and the two dyes lead to a significant difference in the removal effect of two dyes.The degradation mechanism is the redox reaction between Ni^(2+)/Ni^(3+),Fe^(2+)/Fe^(3+)and the synergistic effect of Ni^(3+)/Fe^(2+).Finally,the biotoxicity assessment demonstrated that both the degradation intermediates of mixed dyes and the material itself exhibited low biotoxicity.
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financial support of the Yunnan Major Scientific and Technological Project,China(No.202302AG050008)Yunnan Fundamental Research Project,China(No.202101BE070001-023)“Yunnan Revitalization Talents Support Plan”High-End Foreign Talents Program,China。
文摘The oxidation characteristics of sulfite and thiosulfate were examined by using thermodynamic calculations and simulated desulfurization solution experiments to investigate their difference.Subsequently,a new multistage oxidation method using oxygen−ammonium persulfate was presented and applied to the oxidation of a real desulfurization solution.The results show that the concentrations of thiosulfate and sulfite in the real desulfurization solution decrease from 48.76 and 61.76 g/L to 2.24 and 0.02 g/L,respectively,and the ammonium sulfate products obtained are white with uniform particles.In addition,compared with ammonium persulfate alone,the multistage oxidation method can reduce the ammonium persulfate addition by 37.56%and treatment cost by 28.13%.
基金Funded by the National Natural Science Foundation of China(No.51873167)the Self-determined and Innovative Research Funds of WUT(No.2024-CL-B1-02)。
文摘Modified activated carbons(AS)were fabricated through the oxidation effect of ammonium persulfate and applied to the dynamic adsorption of different acrylate gas.The pore structures,surface chemical properties and surface morphology of AS were respectively characterized by N2 adsorption,Boehm titration,X-ray Photoelectron Spectroscopy(XPS)and scanning electron microscopy(SEM)techniques.After modification,the specific surface area increased from 954 to 1154 m^(2)·g^(-1).The contents of oxygen-containing functional groups on the AS surface increase obviously and have a great effect on the adsorption behavior of acrylate gases.According to the results of dynamic adsorption,the adsorption capacities of acrylates are as the following order:methyl acrylate(461.9 mg·g^(-1))>methyl methacrylate(436.9 mg·g^(-1))>butyl acrylate(381.8 mg·g^(-1)),which is attributed to the size adaptability of AS pores and acrylates.The adsorption behavior of AS for acrylate gases conforms to the Bangham model and the Temkin model.
基金financially supported by the Basal Research Fund of Chinese Academy of Geological Sciences(NO.SK202318)the Natural Science Foundation of Xiamen,China(No.3502Z20227309)the Natural Science Foundation of Fujian Province of China(NO.2023J01227).
文摘Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-ray Diffraction(XRD)were used to characterize the morphology and phase composition of these materials.A series of batch experiments were then conducted to inves-tigate the performance and influencing factors of GO-nZVI activating peroxydisulfate(SPS)for the degra-dation of 1,2,3-trichloropropane(TCP).Finally,an in-situ oxidation reaction zone was created by GO-nZVI-activated SPS in a one-dimensional simulated system to study the remediation of TCP contamination under different aquifer conditions.The results showed that the GO-nZVI composite exhibited a porous,fluffy structure,with spherical nZVI particles loaded onto the surface and folds of the GO sheets.Compared with unmodified nZVI particles,the GO-nZVI composite significantly enhanced the removal efficiency of TCP by activated SPS,achieving a removal rate of 67.2%within an hour-78.2%higher than that of the unmodi-fied system.The SPS dosage and the C/Fe ratio in GO-nZVI were found to significantly affect the degradation efficiency of TCP.The removal rate of TCP increased with higher SPS concentration,and a 10%carbon addition,yielded the best activation effect.The one-dimensional simulation results indicated that the removal rate of TCP ranged from 30.1%to 73.3%under different conditions.A larger medium particle size and higher concentrations of reactants(SPS and GO-nZVI)improved pollutant degradation efficiency,increasing TCP removal by 62.1%,23.8%,and 3.7%,respectively.In contrast,a higher groundwater flow velocity was not conducive to the removal of pollutants,with the TCP removal rate decreasing by approxi-mately 41.9%.
基金supported by the National Natural Science Foundation of China(No.52074069)the Natural Science Foundation of Hebei Province,China(No.E2020501029)+1 种基金the Natural Science Foundation−Steel,the Iron Foundation of Hebei Province,China(No.E2022501030)Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province,China(No.22567627H).
文摘A clean and efficient process for the direct extraction of valuable metals from low-grade nickel sulfide ore through oxidative leaching with(NH_(4))_(2)S_(2)O_(8)under atmosphere pressure was proposed to address the growing demand for nickel and cobalt in the new energy industry.The effects of four key parameters on the metal leaching rates were systematically investigated.Characterization techniques,including XRD,SEM and EDS,were employed to analyze phase transformations during the leaching process.Under optimized conditions,approximately 96.5%of nickel,95.5%of cobalt and 65.2%of copper were successfully extracted.The kinetics of the leaching process was explored to identify the controlling mechanisms of nickel,cobalt and copper dissolution,establishing activation energies and kinetic equations for each metal.The cleanliness and efficiency of this method were confirmed through comparisons with other extraction processes for nickel sulfide ore.
基金Project supported by the National Key Research and Development Program(2022YFC3204900)Jiangsu Province Construction System Technology Project(2023ZD108)。
文摘Sulfamethoxazole(SMZ)is a prevalent and recalcitrant micropollutant in water,posing a significant threat to both aquatic organisms and human health.Therefore,investigating the removal of SMZ is of critical importance.In order to investigate the effect of rare earth metal doping on the performance of activated persulfate oxidative degradation of SMZ,BiFeO_(3)with different Ce doping amounts was successfully prepared by a hydrothermal method.Then,it was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),scanning transmission electro n microscopy(STEM)and Brunauer-Emmett-Teller(BET)method.The performance of porous Ce/BiFeO_(3)in the catalytic activation of persulfate(PMS)for the degradation of SMZ in water was investigated using SMZ solution as a simulated wastewater.The impact of Ce doping rate,catalyst dosage,temperature variations,common anions,natural organic matter,and PMS concentration on SMZ removal was systematically evaluated.The characterization results show that the octahedral rhombic structure of Ce can be observed on the surface of this doped catalyst,and Ce doping does not change the crystalline shape of Ce/BiFeO_(3).The specific surface area of the doped catalyst increases,accompanied by an enlargement of pore size,thereby enhancing the catalyst's adsorption capacity and resistance to contamination by SMZ.Under the optimal conditions of 25℃,SMZ concentration of 20 mg/L,0.8 g/L PMS and 0.3 g/L 0.05Ce/BiFeO_(3)catalyst,the removal rate of SMZ reaches approximately 95%within35 min of reaction time.Even after five cycles of reuse,the degradation rate of SMZ remains above 88%,demonstrating the catalyst's good stability and reusability.Bursting experiments show that SO_(4)^(·-),·OH,1O_(2)and O_(2)^(·-)are involved in the catalytic degradation process,with 1O_(2)playing a dominant role.
基金supported by the National Natural Science Foundation of China(No.21976192).
文摘Persulfate(PS)is a widely used oxidant for the chemical oxidation of organic pollutants.The accurate measurement of PS concentration is crucial for the practical application process.The iodometry is the most recommended method for PS determination,and its principle is based on the redox reaction between S_(2)O_(8)^(2−)and iodide ions.However,hydrogen peroxide(H_(2)O_(2)),an important intermediate product in the process of PS use,often leads to abnormally high determination concentrations of PS.Given this,a novel method was developed for the determination of PS based on the principle of the oxidation of chloride ion(Cl^(−)).The concentration of PS is calculated according to the consumption of Cl^(−)concentration,which is not disturbed by H_(2)O_(2).The optimized test conditions were explored as:C(H^(+))=2 mol/L,T=80◦C,C(Cl^(−)):C(PS)=4:1 and t=30 min.Under the optimized conditions,the limit of detection and the limit of quantification of PS concentration determined by this method were 0.26 and 0.85 g/L,respectively.And the linear range of the PS determination was 1–100 g/L with an error of 0.53%-12.06%.The spike recovery rate for determining PS concentration in the actual wastewater ranged from 94.07%-109.52%.Interfering factors such as H_(2)O_(2),Fe^(3+),MnO_(2)and natural organic matter had almost no effect on the results.This method could not only accurately determine the concentration of PS in industrial wastewater,but also determine the purity of PS industrial products.
基金the National Natural Science Foundation of China(No.52070052)the National Natural Science Foundation of China(No.52300082)+3 种基金National Key Research and Development Program of China(No.2022YFB3805903)the State Key Laboratory of Urban Water Resource and Environment in HIT of China(No.2022TS14)the China Postdoctoral Science Foundation(No.2023M730881)Postdoctoral Fellowship Program of CPSF(No.GZB20230964)。
文摘Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water deteriorates the distillate quality,threatening human health.Herein,we constructed a carbonbased bimetallic(C/FeCo)photothermal membrane by electrospinning technique.Results illustrated that the membrane can catalytically degrade VOCs during SIE with persulfate(PDS)mediation.PDS,as well as phenol,was mainly reacted on the interface of the photothermal membrane instead of in the bulk solution.The interception efficiency of phenol achieved nearly 100%using the C/FeCo membrane during SIE.Hydroxyl radical(•OH),sulfate radical(SO_(4)•−),superoxide radical(O_(2)•−),and singlet oxygen(^(1)O_(2))were identified as the main active substances to degrade VOCs.We also conducted SIE experiments using actual river water to evaluate the practical performance of the C/FeCo membrane.This work holds the promise of VOCs interception during SIE and enlarges the application of solar distillation in water/wastewater treatment.
基金the financial supports from the National Key Research and Development Program of China(Nos.2021YFB3500600,2021YFB3500605,2022YFB3504100)Key R&D Program of Jiangsu Province(No.BE2022142)+6 种基金Ministry of Education Chunhui plan international cooperation project(No.202200554)National Natural Science Foundation of China(No.grant 22208170)Natural Science Foundation of Inner Mongolia(No.2021BS02016)Jiangsu International Cooperation Project(No.BZ2021018)Nanjing Science and Technology Top Experts Gathering Plan,and Open Foundation of State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control(No.SEMPC2023004)Cooperation Foundation for the Chunhui Plan Program of Ministry of Education of China(No.202200554)Open Project Program of Key Laboratory of Opticelectric Sensing and Analytical Chemistry for Life Science(No.M2024-7),MOE。
文摘It has been challenging for Fe(Ⅲ)regeneration in Fe-based photocatalysts for continuous peroxydisulfate(PDS)activation due to the lower ability to reduce Fe(Ⅲ).In this work,Fe-doped ultrathin VO_(2)(Fe-VO_(2))nanobelts were synthesized for purifying metronidazole(MNZ)via PDS activation.As an efficient Fentonlike catalyst for PDS activation,2 wt%Fe-doped VO_(2)can remove 98%of MNZ within 40 min and exhibits impressive recyclability.The synergistic effect of Fe-VO_(2)and Fe(Ⅲ)activated PDS boosted the photocatalytic performance.Moreover,SO_(4)•^(−),h+,O_(2)•^(−),^(1)O_(2),and•OH were the main reactive radicals.The effects of initial MNZ concentration,Fe-VO_(2),PDS dosage,and various anions/cations on MNZ removal by the Fe-VO_(2)/PDS/Vis system were studied.The intermediates of MNZ degradation and possible pathways were determined by density function theory(DFT)calculations and HPLC-MS.This study provided a sustainable technology using Fe-doped ultrathin VO_(2)nanobelts for photocatalytic PDS activation and decontamination of pharmaceutical wastewater.
基金supported by the National Natural Science Foundation of China(50867003)。
文摘This study comprehensively investigates the degradation performance and mechanism of environmental persistent pollutants(EPs)by combining experimental and theoretical calculations with dielectric barrier discharge(DBD)plasma synergized with persulfate.The findings demonstrated that DBD plasma could generate reactive radicals,including·OH,^(1)O_(2) and·O_(2)^(-),which primarily activate persulfate through OH and·O_(2)^(-)to produce the potent oxidizing radical SO_4^(-).This process facilitated enhanced degradation and mineralization of MeP wastewater.The performance of DBD/persulfute(PS)in degrading MeP was evaluated by kinetics,energy efficiency,and co-factor calculations,combined with degradation under different influencing factors.The actives in the system were analyzed by free radical scavenging assays and UV spectrophotometric testing to determine their effects.The findings indicated that persulfate was effectively activated by DBD plasma and that·O_(2)^(-)played a significant role.The presence of persulfate elevated the levels of H_(2)O_(2) and O_(3) in the solution.The intermediates formed during the degradation of MeP were detected using LC-MS and then analyzed alongside density-functional theory(DFT)chemical predictions to anticipate the reactive sites and deduce the potential degradation pathways of methylparaben(MeP).Toxicity evaluation software confirmed that the PS/DBD system reduces acute and developmental toxicity in the water column.The study showed that DBD plasma-activated persulfate was successful in addre ssing newly identified contaminants.
基金co-supported by the National Natural Science Foundation of China(Nos.52176099 and 52306130)the Applied Basic Research Project of Changzhou City,China(No.CJ20235033)the High-Performance Computation Laboratory of Hefei and Changzhou University,China.
文摘To gain insight into the fine interfacial control mechanism exhibited by oxidant-coated Al powder to improve combustion performance,we prepared Al/AP and Al@AP composite fuels using ball milling and spray-drying technology.The thermal reaction characteristics,AP decomposition behavior,and decomposition reaction pathways of Al/AP and Al@AP composite fuels were investigated using thermal analysis and Ab Initio Molecular Dynamics(AIMD)calculations.Under the influence of fine interfacial control,the low-temperature decomposition heat release peak of AP was delayed by 25.5℃,while the high-temperature decomposition peak was advanced by 36.2℃,leading to an increase in the decomposition heat release of AP from 410.7 J/g to 1068.7 J/g.Compared to the unclad structure,the apparent activation energy of AP in low-temperature decomposition increased,and slightly decreased during high-temperature decomposition in the Al@AP composite fuel.The physical model of AP decomposition shifted to the model with higher degrees of freedom and a faster diffusion rate,characterized by rapid bidirectional diffusion at the interface.Furthermore,due to fine interfacial control,the oxidation reaction pathway of Al has been altered,changing from the final products of AP decomposition(O_(2),Cl2,etc.)to the direct oxidation of AP decomposition intermediates(HClO,ClO_(2),etc.).This accelerated and strengthened the oxidation reaction process of Al.As a result of these performance improvements,the final combustion temperature of Al@AP in the Microcanonical Ensemble(NVE)system stabilized at 2370 K,which is significantly higher than 1400 K observed for Al/AP,indicating enhanced ignition and combustion performance.
基金Project(51274255)supported by the National Natural Science Foundation of ChinaProject supported by the Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘The flotabilities of chalcopyrite and galena with sodium humate（HA） and ammonium persulfate（APS） as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO_4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.
基金Project(2007CB613601)supported by the National Basic Research Program of ChinaProject(10C1095)supported by the Foundation of Hunan Educational Committee,China
文摘The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.
基金Project(15A151)supported by the Key Research Projects of Education Department of Hunan Province,ChinaProject(2015JJ2115)supported by the Natural Science Fund Council of Hunan Province,China+1 种基金Project(JSU071308)supported by the Construct Program of the Key Discipline in Hunan Province,ChinaProject(APSTIRT02)supported by the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province,China
文摘The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1-（1-a）^1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed.
基金supported by the National Natural Science Foundation of China(No.21772107)Shandong Province Key Research and Development Plan(No.2019GSF108017)。
文摘An efficient and practical methods for the synthesis of carbamoyl quinoline-2,4-diones via the reaction of ortho-cyanoarylacrylamides with oxamic acids was described.This cyclic reaction could be performed efficiently under metal free conditions.Various products with functional groups could be obtained with moderate to high yields via radical mechanism.
