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
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
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
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
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
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
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
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
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
Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and ...Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and Anemarrhenae Rhizoma(AAR)is a common pairing in traditional Chinese medicine(TCM).According to earlier studies,they possess properties capable of alleviating the adverse impacts of UVR on the skin.However,the specific actions and underlying mechanisms require further investigation.The study aims to analyze the efficacy of AR-AAR in preventing UVR-induced skin damage and to clarify the associated molecular mechanisms.Methods:Potential signaling pathways by which AR and AAR may protect against UVR-induced skin damage were identified with network pharmacology,molecular docking techniques and molecular dynamics(MD)simulation.Except the normal group,the back skin of SD rats was exposed to 1.1 mW/cm^(2) UVA combined with 0.1 mW/cm^(2) UVB daily,and the UVR skin damage model was established.Morphological features of skin tissues of different groups were discovered through Hematoxylin and Eosin(HE)staining,Masson staining,Weigert staining.ELISA was utilized to measure the levels of reactive oxygen species(ROS),Interleukin 6(IL-6),Interleukin 1β(IL-1β)and Tumor necrosis factos-α(TNF-α)in skin tissues.RT-PCR and Western blot were employed to quantify the mRNA and protein contents of PI3K,AKT,and MMP-9.Results:Network pharmacology analysis predicts that AR-AAR may improve skin damage induced by UVR through the PI3K/AKT signaling pathway.Histological staining shows that AR-AAR can significantly reduce inflammatory infiltration and fibrosis in damaged skin.Treatment with AR-AAR(2:1)significantly reduced the expression levels of IL-1β,IL-6,TNF-αand ROS in UVR-damaged rat skin.After treatment with AR-AAR(2:1),not only did the relative mRNA expression levels of PI3K and AKT and the protein expression levels of PI3K,AKT,P-PI3K,and P-AKT increase,but the mRNA and protein expression levels of MMP-9 decreased.Conclusion:The study indicate that the AR-AAR combination and its active components may mitigate UVR skin damage by modulating the PI3K/AKT signaling pathway.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
Oxidation of aniline by persulfate in aqueous solutions was investigated and the reaction kinetic rates under different temperature, persulfate concentration and pH conditions were examined in batch experiments. The r...Oxidation of aniline by persulfate in aqueous solutions was investigated and the reaction kinetic rates under different temperature, persulfate concentration and pH conditions were examined in batch experiments. The results showed that, the aniline degradation followed pseudo first-order reaction model. Aniline degradation rate increased with increasing temperature or persulfate concentration. In the pH range of 3 to 11, a low aniline degradation rate was obtained at strong acid system （pH 3）, while a high degradation rate was achieved at strong alkalinity （pH 11）. Maximum aniline degradation occurred at pH 7 when the solution was in a weak level of acid and alkalinity （pH 5, 7 and 9）. Produced intermediates during the oxidation process were identified using liquid chromatography-mass spectrometry technology. And nitrobenzene, 4-4’-diaminodiphenyl and 1-hydroxy-1,2-diphenylhydrazine have been identified as the major intermediates of aniline oxidation by persulfate and the degradation mechanism of aniline was also tentatively proposed.展开更多
This article, for the first time, provides a novel advanced oxidation process based on sulfate radical （SO^4·-） to degrade organic pollutants in wastewater： microwave （MW）-activated persulfate oxidation （AP...This article, for the first time, provides a novel advanced oxidation process based on sulfate radical （SO^4·-） to degrade organic pollutants in wastewater： microwave （MW）-activated persulfate oxidation （APO） with or without active carbon （AC）. Azo dye acid Orange 7 （AO7） is used as a model compound to investigate the high reactivity of MW-APO. It is found that AO7 （up to 1000 mg/L） is completely decolorized within 5-7 min under an 800 W MW furnace assisted-APO. In the presence of chloride ion （up to 0.50 mol/L）, the decolorization is still 100% completed, though delayed for about 1-2 min. Experiments are made to examine the enhancement by AC. It is exciting to find that the 100% decolorization of AO7 （500 mg/L） is achieved within 3 min by MW-APO using 1.0 g/L AC as catalyst, while the degradation efficiency maintains at 50% by MW energy without persulfate after about 5 min. Besides the destruction of visible light chromophore band of AO7 （484 nm）, during MW-APO, two bands in the ultraviolet region （228 nm and 310 nm） are rapidly broken down. The removal of COD is about 83%-95% for 500 mg/L AO7. SO^4·- is identified with quenching studies using specific alcohols. Both SO^4·- and ·OH could degrade AO7, but SO^4·- plays the dominant role. In a word, MW-APO AC is a new catalytic combustion technology for destruction of organic contamination even for high concentration.展开更多
The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradati...The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradation was found to follow a pseudo-first-order decay model when the persulfate was excessive.The pseudo-first-order rate constants of PCA degradation by persulfate（50 mmol/ L） at pH 7.0 are 0.12×10^-4,0.28×10^-4,0.43×10^-4,0.83×10^-4,1.32×10^-4 s^-1 at 10,20,30,40 and 50℃,respectively. Under the above reaction conditions,the reaction has activation energy of 49.97 kJ/mol.The observed rate was found to be function of temperature and oxidant concentration.Raising temperature and increasing persulfate concentration can significantly accelerate the PCA degradation.展开更多
Removal of polycyclic aromatic hydrocarbons(PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the li...Removal of polycyclic aromatic hydrocarbons(PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the light fraction, which accounted for only 10% of the soil, contained 30% of the PAHs at a concentration of 4352 mg/kg. The heavy fraction contained more high-molecular-weight PAHs, and the total PAH concentration was 625 mg/kg. After being oxidized, the removal rate of PAHs was 39% in the light fraction and nearly 90% in the heavy fraction. Among the different fractions of the heavy fraction,humic acid contained the highest concentration of PAHs, and consequently, the highest removal efficiency of PAHs was also in humic acid. Compared with the light fraction, the heavy fraction has more aromatic compounds and those compounds were broken down during the oxidation process, which may be the removal mechanism involved in the oxidation of high-ring PAHs. Similarly, the enhancement of C= C bonds after oxidation can also explain the poor removal of high-ring PAHs in the light fraction. These results imply that different fractions of soil vary in composition and structure, leading to differences in the distribution and oxidation efficiencies of PAHs.展开更多
The kinetics of aniline degradation by persulfate processes with iron（Ⅱ） activation at ambient temperature was investigated in this study.With iron（Ⅱ） as initiator,the oxidation reactions were found to follow a ...The kinetics of aniline degradation by persulfate processes with iron（Ⅱ） activation at ambient temperature was investigated in this study.With iron（Ⅱ） as initiator,the oxidation reactions were found to follow a biphasic rate phenomenon：a rapid transformation followed by a slow but sustained oxidation process.In the first 30 s,the reaction mainly relies on the persulfate-Fe^（2＋） reaction in which aniline is oxidized rapidly.After 30 s,the aniline was still oxidized but the rate of reaction tended to be slower and the rates were clearly linear-proportional.After the initial fast oxidation,the reactions appeared to follow a pseudo-first-order model.展开更多
Persulfate activation has been applied as one of the efficient advanced oxidation processes(AOPs) to remediate polluted environments. In this study, a novel α-FeOOH anchored by graphene oxide(GO)-carbon nanotubes(CNT...Persulfate activation has been applied as one of the efficient advanced oxidation processes(AOPs) to remediate polluted environments. In this study, a novel α-FeOOH anchored by graphene oxide(GO)-carbon nanotubes(CNTs) aerogel(α-FeOOH@GCA) nanocomposite activated persulfate system(α-FeOOH@GCA + K2S2O8) was applied for decolorization of Orange Ⅱ(OⅡ). The decolorization of OⅡ was remarkably enhanced to a level of ~ 99% in this system compared with that of pristine α-FeOOH(~ 44%) or GO-CNTs(~18%). The enhanced catalytic activity of α-FeOOH@GCA was due to the formation of a heterojunction byα-FeOOH and GO-CNTs as confirmed by the presence of Fe–O–C chemical bonds. The degradation intermediates of OⅡ were comprehensively identified. The proposed degradation pathway of OⅡ begins with the destruction of the conjugated structures of OⅡ by the dominant reactive oxygen species, surface-bound SO4·-. The decolorization efficiency of OⅡ by the α-FeOOH@GCA activated persulfate system decreased from the first to third cycle of recycling. Ultraviolet(UV) irradiation or introduction of a small amount of Fe2+ could restore the activation of this system. The results show that the α-FeOOH@GCA persulfate activation system promises to be a highly efficient environmental remediation method for organic pollutants.展开更多
Persulfate(PS)-based oxidation technologies are attracting increasing attentions in water treatment due to their high efficiency and stability.In this study,a novel diatomite supported MnCeOx composite(MnCeOx/diatomit...Persulfate(PS)-based oxidation technologies are attracting increasing attentions in water treatment due to their high efficiency and stability.In this study,a novel diatomite supported MnCeOx composite(MnCeOx/diatomite) was prepared and characterized for activation of PS to degrade organic pollutants.Results indicated that diatomite not only dispersed MnCeOx and increased the specific surface area of catalyst,but also improved the low-valence metal site(Mn^2+and Ce^3+) and reactive oxygen species site(-OH) of MnCeOx,thus enhancing the activities of MnCeOx.MnCeOx/diatomite/PS showed high efficiency for multiple dyes and pharmaceutical pollutants.Constant rate(k) of MnCeOx/diatomite(kMnCeOx/diatomite) was three times higher than the sum of constant rate of MnCeOx(kMnCeOx)and constant rate of diatomite(kdiatomite).In addition,MnCeOx/diatomite showed wide pH application(5-9).Cl^- and NO3^2- had no effect while SO4^2- and humid acid had slightly negative effects on MnCeOx/diatomite/PS system.Moreover,MnCeOx/diatomite showed good reusability and stability.Mechanism analyses indicated that electron transfer of Mn and Ce attributed to the activation of PS and oxygen to produce free radicals.SO4·^-,·OH and O2·^-on the surface of catalyst were the main active free radicals to attack pollutants.展开更多
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.
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supported by the Shaanxi Qinchuang Yuan“scientist+engineer”team construction(No.2023KXJ-080)Shaanxi Chiral Drug Engineering Technology Research Center(Department of Science and Technology of Shaanxi Province.No.[2011]-251).
文摘Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and Anemarrhenae Rhizoma(AAR)is a common pairing in traditional Chinese medicine(TCM).According to earlier studies,they possess properties capable of alleviating the adverse impacts of UVR on the skin.However,the specific actions and underlying mechanisms require further investigation.The study aims to analyze the efficacy of AR-AAR in preventing UVR-induced skin damage and to clarify the associated molecular mechanisms.Methods:Potential signaling pathways by which AR and AAR may protect against UVR-induced skin damage were identified with network pharmacology,molecular docking techniques and molecular dynamics(MD)simulation.Except the normal group,the back skin of SD rats was exposed to 1.1 mW/cm^(2) UVA combined with 0.1 mW/cm^(2) UVB daily,and the UVR skin damage model was established.Morphological features of skin tissues of different groups were discovered through Hematoxylin and Eosin(HE)staining,Masson staining,Weigert staining.ELISA was utilized to measure the levels of reactive oxygen species(ROS),Interleukin 6(IL-6),Interleukin 1β(IL-1β)and Tumor necrosis factos-α(TNF-α)in skin tissues.RT-PCR and Western blot were employed to quantify the mRNA and protein contents of PI3K,AKT,and MMP-9.Results:Network pharmacology analysis predicts that AR-AAR may improve skin damage induced by UVR through the PI3K/AKT signaling pathway.Histological staining shows that AR-AAR can significantly reduce inflammatory infiltration and fibrosis in damaged skin.Treatment with AR-AAR(2:1)significantly reduced the expression levels of IL-1β,IL-6,TNF-αand ROS in UVR-damaged rat skin.After treatment with AR-AAR(2:1),not only did the relative mRNA expression levels of PI3K and AKT and the protein expression levels of PI3K,AKT,P-PI3K,and P-AKT increase,but the mRNA and protein expression levels of MMP-9 decreased.Conclusion:The study indicate that the AR-AAR combination and its active components may mitigate UVR skin damage by modulating the PI3K/AKT signaling pathway.
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 Foundation of Science and Technology Planning Project of Guangdong Province(No. 2010B050200007)the Fundamental Research Funds for the Central Universities (No. 2011ZM0054)the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (China) (No. 2011K0013)
文摘Oxidation of aniline by persulfate in aqueous solutions was investigated and the reaction kinetic rates under different temperature, persulfate concentration and pH conditions were examined in batch experiments. The results showed that, the aniline degradation followed pseudo first-order reaction model. Aniline degradation rate increased with increasing temperature or persulfate concentration. In the pH range of 3 to 11, a low aniline degradation rate was obtained at strong acid system （pH 3）, while a high degradation rate was achieved at strong alkalinity （pH 11）. Maximum aniline degradation occurred at pH 7 when the solution was in a weak level of acid and alkalinity （pH 5, 7 and 9）. Produced intermediates during the oxidation process were identified using liquid chromatography-mass spectrometry technology. And nitrobenzene, 4-4’-diaminodiphenyl and 1-hydroxy-1,2-diphenylhydrazine have been identified as the major intermediates of aniline oxidation by persulfate and the degradation mechanism of aniline was also tentatively proposed.
文摘This article, for the first time, provides a novel advanced oxidation process based on sulfate radical （SO^4·-） to degrade organic pollutants in wastewater： microwave （MW）-activated persulfate oxidation （APO） with or without active carbon （AC）. Azo dye acid Orange 7 （AO7） is used as a model compound to investigate the high reactivity of MW-APO. It is found that AO7 （up to 1000 mg/L） is completely decolorized within 5-7 min under an 800 W MW furnace assisted-APO. In the presence of chloride ion （up to 0.50 mol/L）, the decolorization is still 100% completed, though delayed for about 1-2 min. Experiments are made to examine the enhancement by AC. It is exciting to find that the 100% decolorization of AO7 （500 mg/L） is achieved within 3 min by MW-APO using 1.0 g/L AC as catalyst, while the degradation efficiency maintains at 50% by MW energy without persulfate after about 5 min. Besides the destruction of visible light chromophore band of AO7 （484 nm）, during MW-APO, two bands in the ultraviolet region （228 nm and 310 nm） are rapidly broken down. The removal of COD is about 83%-95% for 500 mg/L AO7. SO^4·- is identified with quenching studies using specific alcohols. Both SO^4·- and ·OH could degrade AO7, but SO^4·- plays the dominant role. In a word, MW-APO AC is a new catalytic combustion technology for destruction of organic contamination even for high concentration.
基金supported financially by the Foundation of Science and Technology Planning Project of Guangdong Province(No2007A020100001-13)the Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Higher Education Institutions(China)
文摘The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradation was found to follow a pseudo-first-order decay model when the persulfate was excessive.The pseudo-first-order rate constants of PCA degradation by persulfate（50 mmol/ L） at pH 7.0 are 0.12×10^-4,0.28×10^-4,0.43×10^-4,0.83×10^-4,1.32×10^-4 s^-1 at 10,20,30,40 and 50℃,respectively. Under the above reaction conditions,the reaction has activation energy of 49.97 kJ/mol.The observed rate was found to be function of temperature and oxidant concentration.Raising temperature and increasing persulfate concentration can significantly accelerate the PCA degradation.
基金supported by the Key Research Program of the Chinese Academy of Sciences (No. ZDRW-ZS-2016-5-5)the Key Research Program of the Chinese Academy of Sciences (No. KFZD-SW-303)the Science and Technology Plan of Beijing (No. D16110900470000)
文摘Removal of polycyclic aromatic hydrocarbons(PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the light fraction, which accounted for only 10% of the soil, contained 30% of the PAHs at a concentration of 4352 mg/kg. The heavy fraction contained more high-molecular-weight PAHs, and the total PAH concentration was 625 mg/kg. After being oxidized, the removal rate of PAHs was 39% in the light fraction and nearly 90% in the heavy fraction. Among the different fractions of the heavy fraction,humic acid contained the highest concentration of PAHs, and consequently, the highest removal efficiency of PAHs was also in humic acid. Compared with the light fraction, the heavy fraction has more aromatic compounds and those compounds were broken down during the oxidation process, which may be the removal mechanism involved in the oxidation of high-ring PAHs. Similarly, the enhancement of C= C bonds after oxidation can also explain the poor removal of high-ring PAHs in the light fraction. These results imply that different fractions of soil vary in composition and structure, leading to differences in the distribution and oxidation efficiencies of PAHs.
基金supported by a grant from E.I.du Pont de Nemours and Company to Rutgers University.Partial funding wasalso provided by the Natural Science Foundation of Guangdong Province(No.9351064101000001)Science and Technology Planning Project of Guangdong Province(No.2007A020100001-13)the Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Higher Education Institutions(China)
文摘The kinetics of aniline degradation by persulfate processes with iron（Ⅱ） activation at ambient temperature was investigated in this study.With iron（Ⅱ） as initiator,the oxidation reactions were found to follow a biphasic rate phenomenon：a rapid transformation followed by a slow but sustained oxidation process.In the first 30 s,the reaction mainly relies on the persulfate-Fe^（2＋） reaction in which aniline is oxidized rapidly.After 30 s,the aniline was still oxidized but the rate of reaction tended to be slower and the rates were clearly linear-proportional.After the initial fast oxidation,the reactions appeared to follow a pseudo-first-order model.
基金supported by China’s National Science Foundation(No.21377039)
文摘Persulfate activation has been applied as one of the efficient advanced oxidation processes(AOPs) to remediate polluted environments. In this study, a novel α-FeOOH anchored by graphene oxide(GO)-carbon nanotubes(CNTs) aerogel(α-FeOOH@GCA) nanocomposite activated persulfate system(α-FeOOH@GCA + K2S2O8) was applied for decolorization of Orange Ⅱ(OⅡ). The decolorization of OⅡ was remarkably enhanced to a level of ~ 99% in this system compared with that of pristine α-FeOOH(~ 44%) or GO-CNTs(~18%). The enhanced catalytic activity of α-FeOOH@GCA was due to the formation of a heterojunction byα-FeOOH and GO-CNTs as confirmed by the presence of Fe–O–C chemical bonds. The degradation intermediates of OⅡ were comprehensively identified. The proposed degradation pathway of OⅡ begins with the destruction of the conjugated structures of OⅡ by the dominant reactive oxygen species, surface-bound SO4·-. The decolorization efficiency of OⅡ by the α-FeOOH@GCA activated persulfate system decreased from the first to third cycle of recycling. Ultraviolet(UV) irradiation or introduction of a small amount of Fe2+ could restore the activation of this system. The results show that the α-FeOOH@GCA persulfate activation system promises to be a highly efficient environmental remediation method for organic pollutants.
基金supported by the National Water Pollution Control and Treatment Science and Technology Major Project (No.2018ZX07110003).
文摘Persulfate(PS)-based oxidation technologies are attracting increasing attentions in water treatment due to their high efficiency and stability.In this study,a novel diatomite supported MnCeOx composite(MnCeOx/diatomite) was prepared and characterized for activation of PS to degrade organic pollutants.Results indicated that diatomite not only dispersed MnCeOx and increased the specific surface area of catalyst,but also improved the low-valence metal site(Mn^2+and Ce^3+) and reactive oxygen species site(-OH) of MnCeOx,thus enhancing the activities of MnCeOx.MnCeOx/diatomite/PS showed high efficiency for multiple dyes and pharmaceutical pollutants.Constant rate(k) of MnCeOx/diatomite(kMnCeOx/diatomite) was three times higher than the sum of constant rate of MnCeOx(kMnCeOx)and constant rate of diatomite(kdiatomite).In addition,MnCeOx/diatomite showed wide pH application(5-9).Cl^- and NO3^2- had no effect while SO4^2- and humid acid had slightly negative effects on MnCeOx/diatomite/PS system.Moreover,MnCeOx/diatomite showed good reusability and stability.Mechanism analyses indicated that electron transfer of Mn and Ce attributed to the activation of PS and oxygen to produce free radicals.SO4·^-,·OH and O2·^-on the surface of catalyst were the main active free radicals to attack pollutants.
