A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline...A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous structure.The adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic performance.Moreover,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical calculation.Considering the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.展开更多
This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level(MPL)of sulfites in GB2760-2011.Sulfites as food additives ar...This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level(MPL)of sulfites in GB2760-2011.Sulfites as food additives are overused or abused in many food categories.When the MPL in GB 2760-2011 was used as sulfites content in food,the intake of sulfites in most surveyed populations was lower than the acceptable daily intake(ADI).Excess intake of sulfites was found展开更多
Efficient utilization of wheat straw residue(WSR) from pulp mills is an important priority for the sustainable development of the pulp and paper industry. In this study, the effects of ammonium sulfite(AS) pretreatmen...Efficient utilization of wheat straw residue(WSR) from pulp mills is an important priority for the sustainable development of the pulp and paper industry. In this study, the effects of ammonium sulfite(AS) pretreatment with different AS charges(wt%) and pretreatment temperatures on the chemical composition and enzymatic hydrolysis of WSR were studied. The results revealed that more lignin was removed with the increase of pretreatment temperature and AS charge. The degradation of hemicellulose became severe at high pretreatment temperature, while cellulose remained stable during the pretreatment process. The enzymatic hydrolysis efficiency of pretreated WSR was increased and then decreased with the increase of the AS charge and pretreatment temperature. The AS charge exerts a stronger effect on enzymatic hydrolysis efficiency than the pretreatment temperature. Glucan and xylan conversion ratios up to 88.9% and 44.9%, respectively, were obtained. The highest total sugar conversion ratio was 67.0% when WSR pretreated with 16% AS at 165℃ was hydrolyzed with a cellulase loading of 40 FPU per gram of glucan.展开更多
The aqueous polymerization of methyl methacrylate initiated by copper polypropylene-based polyamidoxime （PPAO-Cu） -sodium sulfite system was investigated. The overall rate of polymerization （R<sub>p</sub&...The aqueous polymerization of methyl methacrylate initiated by copper polypropylene-based polyamidoxime （PPAO-Cu） -sodium sulfite system was investigated. The overall rate of polymerization （R<sub>p</sub>） isR<sub>p</sub>=9.7 x 10<sup>12</sup> e<sup>-21.200/RT</sup> [MMA]<sup>O.88</sup>[Na<sub>2</sub> SO<sub>3</sub>]<sup>0.50</sup>The length of the induction period （τ） is inversely proportional to the concentration of sodium sultite and independent of the amount of polymer supported copper and the concentration of monomer. It could be expressed as follows:1/τ=1.2x10<sup>12</sup>e<sup>-15.600/RT</sup>[Na<sub>2</sub>SO<sub>3</sub>]=K<sub>τ</sub>R<sub>i</sub>The polymerization is initiated by a primary radical generated from the redox reaction rather than induced by "coordination-proton transfer" mechanism.展开更多
The use of bisulfite in food and beverage preservation, as well as in commercial goods and pharmaceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stress...The use of bisulfite in food and beverage preservation, as well as in commercial goods and pharmaceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stressed that its action is connected to the presence of NO, and the only reported/ hypothesized evidence concerns the possible interaction with GSNO (S-nitrosoglutathione), an NO releaser. In this light, we investigated the interaction between GSNO and the bisulfite in an aqueous medium at pH = 6.4;actually, a positive effect of the sulfite was evidenced. i.e., the S-nitrosoglutathione becomes a more efficient NO-releaser. But, the nitrite is the real pool of NO in vivo, therefore we investigate its interaction with the bisulfite in an aqueous acidic solution at pH = 6.4;this time, a definitely efficient and abundant NO release, 3.61 times higher compared to the GSNO, has been evidenced. Therefore, these results allow hypothesizing a fundamental role of NO in the bisulfite’s action in vivo, or most probably the bisulfite acts simply as cofactor of NO-releasers.展开更多
In this paper, a novel chemiluminescence (CL) method for the determination of tramadol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite an...In this paper, a novel chemiluminescence (CL) method for the determination of tramadol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic KMnO4. A mechanism for the CL reaction has been proposed on the basis of fluorescent and CL spectra. Under the optimized conditions, the proposed method allows the measurement of tramadol hydrochloride over the range of 0.04 - 4 ?g/mLwith a correlation coefficient of 0.9995 (n = 8) and a detection limit of 0.01 ?g/mL (3σ), and the relative standard deviation for 2.0 ?g/mL tramadol (n = 11) is 2.1%. The utility of this method was demonstrated by determining tramadol hydrochloride in tablets and injections.展开更多
Permanganate/sulfite(Mn(VII)/S(IV))process is a promising pre-oxidation technology for sequestering the emerging organic contaminants in drinking water treatment plant.Iopamidol(IPM),a representative of iodinated X-ra...Permanganate/sulfite(Mn(VII)/S(IV))process is a promising pre-oxidation technology for sequestering the emerging organic contaminants in drinking water treatment plant.Iopamidol(IPM),a representative of iodinated X-ray contrast media,has been widely detected in water sources and has the risk of forming iodinated disinfection byproducts(I-DBPs)in water treatment system.In this study,we investigated the evolution of iodine species during the IPM degradation by the Mn(VII)/S(IV)process and its effect on the subsequent formation of I-DBPs during chlorination at pH 7.0 and 8.0.IPM could be effectively degraded in the Mn(VII)/S(IV)process at environmentally relevant pH(pH 7.0 and 8.0).The results of quenching and competitive oxidation kinetic experiments revealed that SO^(·-)_(4)was the major reactive oxidizing species contributing to the degradation of IPM whereas the contributions of HO·and reactive manganese species were negligible in the Mn(VII)/S(IV)process.I–and IO–3were generated while no HOI was detected during the degradation of IPM in the Mn(VII)/S(IV)process.The effects of IPM oxidation by Mn(VII)/S(IV)on the subsequent formation of chlorinated disinfection by-products(Cl-DBPs)during chlorination were related to the category of Cl-DBPs.The pre-oxidation of IPM by Mn(VII)/S(IV)resulted in the generation of I-DBPs during the disinfection process although no I-DBPs were detected if no pre-oxidation was applied.The finding of this study suggested that attention should be paid to the toxicity of DBPs when water containing iodinated organic contaminants is treated by Mn(VII)/S(IV)process or other pre-oxidation technologies.展开更多
Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous a...Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous activator for sulfite (Ni Co_(2)O_(4)@BC-sulfite) to degrade atrazine (ATZ) in the neutral environment.The synergistic coupling of BC and Ni Co_(2)O_(4)endows the resulting composite excellent catalytic activity.82% of the degradation ratio of ATZ (1 mg/L) could be achieved within 10 min at initial concentrations of 0.6 g/L Ni Co_(2)O_(4)@BC,3.0 mmol/L sulfite in neutral environment.When further supplementing sulfite into the system at 20 min (considering the depletion of sulfite),outstanding degradation efficiency (100%) were achieved in the next 10 min without any other energy input by the Ni Co_(2)O_(4)@BC-sulfite system.The features of the prepared catalysts and the effects of some key parameters on ATZ degradation were systematically examined.A strong inner-sphere complexation (≡Co_(2)+/Ni^(2+)-SO_(3)^(2-)) was explored between sulfite and the metal sites on the Ni Co_(2)O_(4)@BC surface.The redox cycle of the surface metal efficiently mediated sulfite activation and triggered the series radical chain reactions.The generated radicals,in particular the surface-bound radicals were involved in ATZ degradation.High performance liquid chromatography-tandem mass spectrometry (LC-MS) technique was used to detect the degradation intermediates.Density functional theory (DFT) calculations were performed to illustrate the possible degradation pathways of ATZ.Finally,an underlying mechanism for ATZ removal was proposed.The present study offered a low-cost and sustainable catalyst for sulfite activation to remove ATZ in an environmentally friendly manner from wastewater.展开更多
The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP...The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP by both processes followed the first-order rate law with comparable reaction rate constants of 1.50×10^(-3)sec^(−1)and 1.20×10^(-3)sec^(−1),respectively.Scavenging experiments demonstrated that both e^(−)_(aq)and H·played a crucial role in MTP degradation by the UV/sulfite as an ARP,while SO_(4)^(·−)was the dominant oxidant in the UV/sulfite AOP.The degradation kinetics of MTP by the UV/sulfite as an ARP and AOP shared a similar pH dependence with a minimum rate obtained around pH 8.The results could be well explained by the pH impacts on the MTP speciation and sulfite species.Totally six transformation products(TPs)were identified from MTP degradation by the UV/sulfite ARP,and two additional ones were detected in the UV/sulfite AOP.The benzene ring and ether groups of MTP were proposed as the major reactive sites for both processes based on molecular orbital calculations by density functional theory(DFT).The similar degradation products of MTP by the UV/sulfite process as an ARP and AOP indicated that e^(−)_(aq)/H·and SO_(4)^(·−)might share similar reaction mechanisms,primarily including hydroxylation,dealkylation,and H abstraction.The toxicity of MTP solution treated by the UV/sulfite AOP was calculated to be higher than that in the ARP by the Ecological Struc-ture Activity Relationships(ECOSAR)software,due to the accumulation of TPs with higher toxicity.展开更多
Trimethylphenol is an organic toxic byproduct of industrial process,which is difficult to be eliminated through conventional degradation without harsh conditions.In this work,a sulfite-based oxidation process activate...Trimethylphenol is an organic toxic byproduct of industrial process,which is difficult to be eliminated through conventional degradation without harsh conditions.In this work,a sulfite-based oxidation process activated by ZnO-embedded hydrogel was studied for the degradation of 2,4,6-trimethylphenols in the ambient conditions.The ZnO/Na_(2)SO_(3)oxidative system can effectively degrade trimethylphenol via the generation of radicals such as SO_(4)^(-)·,OH·,and SO_(3)^(−)·.The presence of hydrogel matrix facilitates the distribution and recyclability of ZnO catalysts while maintaining high degradation kinetics and little leaching of metal ions.Results suggest the promising potential of ZnO-hydrogel in wastewater treatment with good performance in terms of pH sensitivity,anion interference,recyclability,etc.The combination of ZnO catalysts,hydrogel,and sulfite-based advanced oxidation process may provide essential support for the current treatment of alkylated phenols with strong potential in the commercial scale-ups.展开更多
Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles ...Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles to form the p-n heterojunction(Co_(3)O_(4)/TiO_(2)) to degrade acetaminophen(ACE) through photocatalytic activation of sulfite.Specifically,X-ray photoelectron spectroscopy analysis and theoretical calculations provide compelling evidence of electron transfer from Co_(3)O_(4) to TiO_(2) at the heterointerface.The interfacial electron redistribution of Co_(3)O_(4)/TiO_(2) tunes the adsorption energy of HSO_(3)^(-)/SO_(3)^(2-) in sulfite activation process for enhanced the catalytic activity.Owing to its unique heterointerface,the degradation efficiency of ACE reached 96.78%within 10 min.The predominant active radicals were identified as ·OH,h^(+),and SO_(x)^(·-) through radical quenching experiments and electron spin resonance capture.Besides,the possible degradation pathway was deduced by monitoring the generated intermediate products.Thereafter,the enhanced roles of well-engineered compositing interface in photocatalytic activation of sulfite for complete degradation of ACE were unveiled that it can improve light absorption ability,facilitate the generation of active species,and optimize reactive pathways.Considering that sulfite is a waste from flue gas desulfurization process,the photocatalytic activation of sulfite system will open up new avenues of beneficial use of air pollutants for the removal of pharmaceutical wastewater.展开更多
Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparti...Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparticles embedded in nitrogen-doped graphite layers(Co@NC),were used to activate SO32−for removal of Methyl Orange in aqueous solution.The Co@NC catalysts were synthesized via pyrolysis of Co^(2+)-based metal-organic framework(Co-MOF),where CoO was firstly formed at 400℃ and then partially reduced to Co nanoparticles embedded in carbon layers at 800℃.The Co@NC catalysts were more active than other cobaltbased catalysts such as Co^(2+),Co_(3)O_(4) and CoFe_(2)O_(4),due to the synergistic effect of metallic Co and CoxOy.A series of chain reaction between Co species and dissolved oxygen was established,with the production and transformation of SO_(3)•−,SO_(5)^(2−),and subsequent active radicals SO_(4)•−and HO•.In addition,HCO_(3)−was found to play a key role in the reaction by complexing with Co species on the surface of the catalysts.The results provide a new promising strategy by using the Co@NC catalyst for SO3_(2)−oxidation to promote organic pollutants degradation.展开更多
Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been suc...Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.展开更多
Rapid,selective,and quantitative profiling of SO_(3)^(2-)is a prerequisite for investigating its effect on different physiopathological processes.To address this challenge,our team prepared a ratiometric fluorescent p...Rapid,selective,and quantitative profiling of SO_(3)^(2-)is a prerequisite for investigating its effect on different physiopathological processes.To address this challenge,our team prepared a ratiometric fluorescent probe HBTCS,based on 4-(benzothiazol-2-yl)-3-hydroxybenzaldehyde for specific detection of SO_(3)^(2-)under a singlewavelength excitation.The solution of probe HBTC-S itself exhibited orange fluorescence(λ_(em)=614 nm),and became green fluorescent(λ_(em)=471 nm)after the addition of SO_(3)^(2-).The vitro experiments suggested that the probe displayed high sensitivity,excellent selectivity,and a low detection limit(0.15μM).Moreover,probe HBTC-S was successfully applied for qualitative and quantitative monitoring of SO_(3)^(2-)in realistic samples and living HeLa cells in a ratiometric manner.展开更多
Halogenated aromatic compounds have attracted increasing concerns due to their toxicity and persistency in the environment, and dehalogenation is one of the promising treatment and detoxification methods. Herein, we s...Halogenated aromatic compounds have attracted increasing concerns due to their toxicity and persistency in the environment, and dehalogenation is one of the promising treatment and detoxification methods. Herein, we systematically studied the debromination efficiency and mechanism of para-bromophenol(4-BP) by a recently developed UV/sulfite process. 4-BP underwent rapid degradation with the kinetics accelerated with the increasing sulfite concentration, pH(6.1–10) and temperature, whereas inhibited by dissolved oxygen and organic solvents. The apparent activation energy was estimated to be 27.8 kJ/mol. The degradation mechanism and pathways of 4-BP were explored by employing N_2O and nitrate as the electron scavengers and liquid chromatography/mass spectrometry to identify the intermediates. 4-BP degradation proceeded via at least two pathways including direct photolysis and hydrated electron-induced debromination. The contributions of both pathways were distinguished by quantifying the quantum yields of 4-BP via direct photolysis and hydrated electron production in the system. 4-BP could be readily completely debrominated with all the substituted Br released as Br-, and the degradation pathways were also proposed. This study would shed new light on the efficient dehalogenation of brominated aromatics by using the UV/sulfite process.展开更多
One-sixth of the currently known natural products containα,β-unsaturated carbonyl groups.Our previous studies reported a rare C-sulfonate metabolic pathway.Sulfonate groups were linked to theβ-carbon ofα,β-unsatu...One-sixth of the currently known natural products containα,β-unsaturated carbonyl groups.Our previous studies reported a rare C-sulfonate metabolic pathway.Sulfonate groups were linked to theβ-carbon ofα,β-unsaturated carbonyl-based natural compounds through this pathway.However,the mechanism of this type of metabolism is still not fully understood,especially whether it is formed through enzyme-mediated biotransformation or direct sulfite addition.In this work,the enzyme-mediated and non-enzymatic pathways were studied.First,the sulfite content in rat intestine was determined by LC-MS/MS.The results showed that the amount of sulfite in rat intestinal contents was from 41.5 to 383μg·g^(-1),whereas the amount of sulfite in rat feed was lower than the lower limit of quantitation(20μg·g^(-1)).Second,the reaction kinetics of sulfite-andrographolide reactions in phosphate buffer solutions(pH 6-8)was studied.The half-lives of andrographolide ranged from minutes to hours.This was suggested that the C-sulfonate reaction of andrographolide was very fast.Third,the C-sulfonate metabolites of andrographolide were both detected when andrographolide and L-cysteine-S-conjugate andrographolide were incubated with the rat small intestine contents or sulfite,indicating that the sulfite amount in rat intestine contents was high enough to react with andrographolide,which assisted a significant portion of andrographolide metabolism.Finally,the comparison of andrographolide metabolite profiles among liver homogenate(with NADPH),liver S9(with NADPH),small intestine contents homogenate(with no NADPH),and sulfite solution incubations showed that the C-sulfonate metabolites were predominantly generated in the intestinal tract by non-enzymatic pathway.In summary,sulfite can serve as a substrate for C-sulfonate metabolism,and these results identified non-enzymatically nucleophilic addition as the potential mechanism for C-sulfonate metabolism of compounds containingα,β-unsaturated carbonyl moiety.展开更多
The ligand-stabilized soluble Mn(Ⅲ) recognized as active intermediate can potentially mediate the attenuation of contaminants. In this study,the abiotic degradation behaviors of methyl parathion in the ligand stabili...The ligand-stabilized soluble Mn(Ⅲ) recognized as active intermediate can potentially mediate the attenuation of contaminants. In this study,the abiotic degradation behaviors of methyl parathion in the ligand stabilized Mn(Ⅲ)-sulfite system were investigated. The results showed that the yield of soluble Mn(Ⅲ) produced from the redox reaction of MnO2 and oxalic acid was dependent linearly on the dosage of Mn O2 and caused the decomposition of methyl parathion up to 50.1% in Mn(Ⅲ)-sulfite system after 30 minutes. The fitted pseudo-first-order reaction constants of methyl parathion degradation increased with the increasing of the amount of produced Mn(Ⅲ) but was not effected linearly by the addition of sulfite. Other ligands,including pyrophosphate and oxalic acid,acted as effective complexing agents to stabilize soluble Mn(Ⅲ),and exhibited competitive effect on methyl parathion degradation with sulfite. The formation of Mn(Ⅲ)-sulfite complexes is the critical step in the system to produce abundant reactive oxygen species identified as SO3·-to facilitate methyl parathion degradation. The hydrolysis and oxidation of methyl parathion were acknowledged as two primary transformation mechanisms in Mn(Ⅲ)-sulfite system. These findings indicate that naturally ligands-stabilized soluble Mn(Ⅲ) can be generated and could oxidatively decompose organophosphate pesticides such as methyl parathion.展开更多
Oxidation of sulfite is an important process in wet flue gas desulfurization.Using highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus,the intri...Oxidation of sulfite is an important process in wet flue gas desulfurization.Using highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus,the intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid was investigated under four dif-ferent conditions.The reaction order of the reagents and the activation energy were obtained.The re-sults indicate that water quality and light have no obvious effects on the reaction order and activation energy,but have an influence on the reaction rate constant.The mechanism of the intrinsic reaction is proposed.The results derived with this mechanism are in good agreement with the experimental re-sults.展开更多
Accelerating the(NH_4)_(2)SO_(3) oxidation gives rise to the reclaiming of byproduct, while there are secondary environmental risks from reduction of the coexisted selenium species by sulfite. In this study, a bi-func...Accelerating the(NH_4)_(2)SO_(3) oxidation gives rise to the reclaiming of byproduct, while there are secondary environmental risks from reduction of the coexisted selenium species by sulfite. In this study, a bi-functional Co-SBA-15-SH, were synthesized through Co impregnation and sulfhydryl(-SH) decoration, which can simultaneously uptake Se and accelerate sulfite oxidation efficiently. Meanwhile, the adsorption kinetics and migration mechanism of Se species were revealed through characterization and density functional calculations, with maximum adsorption capacity of 223 mg/g. The inhibition of Se~0 re-emission and poisonous effect of Se on sulfite oxidation was also investigated. Using the findings of this study, the ammonia desulfurization can be improved by enabling purification of the byproduct and lowering the toxicity of effluent by removing toxic pollutants.展开更多
基金gratefully acknowledge the financial support for this research from the National Natural Science Foundation of China(Grant No.:21978047,21776046)the Six Talent Climax Foundation of Jiangsu(Grant No.:XCL-079).
文摘A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous structure.The adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic performance.Moreover,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical calculation.Considering the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.
文摘This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level(MPL)of sulfites in GB2760-2011.Sulfites as food additives are overused or abused in many food categories.When the MPL in GB 2760-2011 was used as sulfites content in food,the intake of sulfites in most surveyed populations was lower than the acceptable daily intake(ADI).Excess intake of sulfites was found
文摘Efficient utilization of wheat straw residue(WSR) from pulp mills is an important priority for the sustainable development of the pulp and paper industry. In this study, the effects of ammonium sulfite(AS) pretreatment with different AS charges(wt%) and pretreatment temperatures on the chemical composition and enzymatic hydrolysis of WSR were studied. The results revealed that more lignin was removed with the increase of pretreatment temperature and AS charge. The degradation of hemicellulose became severe at high pretreatment temperature, while cellulose remained stable during the pretreatment process. The enzymatic hydrolysis efficiency of pretreated WSR was increased and then decreased with the increase of the AS charge and pretreatment temperature. The AS charge exerts a stronger effect on enzymatic hydrolysis efficiency than the pretreatment temperature. Glucan and xylan conversion ratios up to 88.9% and 44.9%, respectively, were obtained. The highest total sugar conversion ratio was 67.0% when WSR pretreated with 16% AS at 165℃ was hydrolyzed with a cellulase loading of 40 FPU per gram of glucan.
基金This poject supported by the National Natural Science Foundation of China.
文摘The aqueous polymerization of methyl methacrylate initiated by copper polypropylene-based polyamidoxime （PPAO-Cu） -sodium sulfite system was investigated. The overall rate of polymerization （R<sub>p</sub>） isR<sub>p</sub>=9.7 x 10<sup>12</sup> e<sup>-21.200/RT</sup> [MMA]<sup>O.88</sup>[Na<sub>2</sub> SO<sub>3</sub>]<sup>0.50</sup>The length of the induction period （τ） is inversely proportional to the concentration of sodium sultite and independent of the amount of polymer supported copper and the concentration of monomer. It could be expressed as follows:1/τ=1.2x10<sup>12</sup>e<sup>-15.600/RT</sup>[Na<sub>2</sub>SO<sub>3</sub>]=K<sub>τ</sub>R<sub>i</sub>The polymerization is initiated by a primary radical generated from the redox reaction rather than induced by "coordination-proton transfer" mechanism.
文摘The use of bisulfite in food and beverage preservation, as well as in commercial goods and pharmaceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stressed that its action is connected to the presence of NO, and the only reported/ hypothesized evidence concerns the possible interaction with GSNO (S-nitrosoglutathione), an NO releaser. In this light, we investigated the interaction between GSNO and the bisulfite in an aqueous medium at pH = 6.4;actually, a positive effect of the sulfite was evidenced. i.e., the S-nitrosoglutathione becomes a more efficient NO-releaser. But, the nitrite is the real pool of NO in vivo, therefore we investigate its interaction with the bisulfite in an aqueous acidic solution at pH = 6.4;this time, a definitely efficient and abundant NO release, 3.61 times higher compared to the GSNO, has been evidenced. Therefore, these results allow hypothesizing a fundamental role of NO in the bisulfite’s action in vivo, or most probably the bisulfite acts simply as cofactor of NO-releasers.
文摘In this paper, a novel chemiluminescence (CL) method for the determination of tramadol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic KMnO4. A mechanism for the CL reaction has been proposed on the basis of fluorescent and CL spectra. Under the optimized conditions, the proposed method allows the measurement of tramadol hydrochloride over the range of 0.04 - 4 ?g/mLwith a correlation coefficient of 0.9995 (n = 8) and a detection limit of 0.01 ?g/mL (3σ), and the relative standard deviation for 2.0 ?g/mL tramadol (n = 11) is 2.1%. The utility of this method was demonstrated by determining tramadol hydrochloride in tablets and injections.
基金supported by the National Natural Science Foundation of China (Nos.22206050,22025601,21976133 and 52270047)the National Key Research and Development Program of China (No.2019YFC1805202)the State Key Laboratory of Pollution Control and Resource Reuse Foundation (No.PCRRK20014)。
文摘Permanganate/sulfite(Mn(VII)/S(IV))process is a promising pre-oxidation technology for sequestering the emerging organic contaminants in drinking water treatment plant.Iopamidol(IPM),a representative of iodinated X-ray contrast media,has been widely detected in water sources and has the risk of forming iodinated disinfection byproducts(I-DBPs)in water treatment system.In this study,we investigated the evolution of iodine species during the IPM degradation by the Mn(VII)/S(IV)process and its effect on the subsequent formation of I-DBPs during chlorination at pH 7.0 and 8.0.IPM could be effectively degraded in the Mn(VII)/S(IV)process at environmentally relevant pH(pH 7.0 and 8.0).The results of quenching and competitive oxidation kinetic experiments revealed that SO^(·-)_(4)was the major reactive oxidizing species contributing to the degradation of IPM whereas the contributions of HO·and reactive manganese species were negligible in the Mn(VII)/S(IV)process.I–and IO–3were generated while no HOI was detected during the degradation of IPM in the Mn(VII)/S(IV)process.The effects of IPM oxidation by Mn(VII)/S(IV)on the subsequent formation of chlorinated disinfection by-products(Cl-DBPs)during chlorination were related to the category of Cl-DBPs.The pre-oxidation of IPM by Mn(VII)/S(IV)resulted in the generation of I-DBPs during the disinfection process although no I-DBPs were detected if no pre-oxidation was applied.The finding of this study suggested that attention should be paid to the toxicity of DBPs when water containing iodinated organic contaminants is treated by Mn(VII)/S(IV)process or other pre-oxidation technologies.
基金supported by the National Science Foundation of China (Nos.22076057,21777052)the National Key R&D Program of China (No.2018YFC1802003)+1 种基金the Project for Application Foundation Frontier for Wuhan (No.2019020701011486)The Program of Introducing Talents of Discipline to Universities of China (111 program,B17019)。
文摘Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous activator for sulfite (Ni Co_(2)O_(4)@BC-sulfite) to degrade atrazine (ATZ) in the neutral environment.The synergistic coupling of BC and Ni Co_(2)O_(4)endows the resulting composite excellent catalytic activity.82% of the degradation ratio of ATZ (1 mg/L) could be achieved within 10 min at initial concentrations of 0.6 g/L Ni Co_(2)O_(4)@BC,3.0 mmol/L sulfite in neutral environment.When further supplementing sulfite into the system at 20 min (considering the depletion of sulfite),outstanding degradation efficiency (100%) were achieved in the next 10 min without any other energy input by the Ni Co_(2)O_(4)@BC-sulfite system.The features of the prepared catalysts and the effects of some key parameters on ATZ degradation were systematically examined.A strong inner-sphere complexation (≡Co_(2)+/Ni^(2+)-SO_(3)^(2-)) was explored between sulfite and the metal sites on the Ni Co_(2)O_(4)@BC surface.The redox cycle of the surface metal efficiently mediated sulfite activation and triggered the series radical chain reactions.The generated radicals,in particular the surface-bound radicals were involved in ATZ degradation.High performance liquid chromatography-tandem mass spectrometry (LC-MS) technique was used to detect the degradation intermediates.Density functional theory (DFT) calculations were performed to illustrate the possible degradation pathways of ATZ.Finally,an underlying mechanism for ATZ removal was proposed.The present study offered a low-cost and sustainable catalyst for sulfite activation to remove ATZ in an environmentally friendly manner from wastewater.
基金This study was supported by the Guangdong introducing innovative and entrepreneurial teams(No.2019ZT08L213)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0403)+2 种基金the National Natural Science Foundation of China(Nos.51979044 and 42177045)the Young Talent Project of Beijing Normal University at Zhuhai(No.310432101)We also thank the support received from China Scholarship Council(CSC)for providing a graduate fellowship to Y.C.(No.202006120356).
文摘The degradation of metoprolol(MTP)by the UV/sulfite with oxygen as an advanced reduction process(ARP)and that without oxygen as an advanced oxidation process(AOP)was comparatively studied herein.The degradation of MTP by both processes followed the first-order rate law with comparable reaction rate constants of 1.50×10^(-3)sec^(−1)and 1.20×10^(-3)sec^(−1),respectively.Scavenging experiments demonstrated that both e^(−)_(aq)and H·played a crucial role in MTP degradation by the UV/sulfite as an ARP,while SO_(4)^(·−)was the dominant oxidant in the UV/sulfite AOP.The degradation kinetics of MTP by the UV/sulfite as an ARP and AOP shared a similar pH dependence with a minimum rate obtained around pH 8.The results could be well explained by the pH impacts on the MTP speciation and sulfite species.Totally six transformation products(TPs)were identified from MTP degradation by the UV/sulfite ARP,and two additional ones were detected in the UV/sulfite AOP.The benzene ring and ether groups of MTP were proposed as the major reactive sites for both processes based on molecular orbital calculations by density functional theory(DFT).The similar degradation products of MTP by the UV/sulfite process as an ARP and AOP indicated that e^(−)_(aq)/H·and SO_(4)^(·−)might share similar reaction mechanisms,primarily including hydroxylation,dealkylation,and H abstraction.The toxicity of MTP solution treated by the UV/sulfite AOP was calculated to be higher than that in the ARP by the Ecological Struc-ture Activity Relationships(ECOSAR)software,due to the accumulation of TPs with higher toxicity.
基金the Natural Science Foundation of Shandong Province(No.ZR2017LB028)the Key Research and Development Program of Shandong Province(Nos.2018GSF118032 and 2022CXGC020415)the Fundamental Research Funds for the Central Universities in China(No.18CX02125A).Y.X.L.is grateful for the Research Subsidy Funds of Marine Science Research Institute of Shandong Province.X.W.C.is grateful for Ministry of Science,Innovation and Universities of Spain with project reference number of PID2020-113809RBC33 and by Junta de Andalucía(Spain)with reference number of PY18-2727.
文摘Trimethylphenol is an organic toxic byproduct of industrial process,which is difficult to be eliminated through conventional degradation without harsh conditions.In this work,a sulfite-based oxidation process activated by ZnO-embedded hydrogel was studied for the degradation of 2,4,6-trimethylphenols in the ambient conditions.The ZnO/Na_(2)SO_(3)oxidative system can effectively degrade trimethylphenol via the generation of radicals such as SO_(4)^(-)·,OH·,and SO_(3)^(−)·.The presence of hydrogel matrix facilitates the distribution and recyclability of ZnO catalysts while maintaining high degradation kinetics and little leaching of metal ions.Results suggest the promising potential of ZnO-hydrogel in wastewater treatment with good performance in terms of pH sensitivity,anion interference,recyclability,etc.The combination of ZnO catalysts,hydrogel,and sulfite-based advanced oxidation process may provide essential support for the current treatment of alkylated phenols with strong potential in the commercial scale-ups.
基金financially supported by the National Natural Science Foundation of China(No.51878273)the Natural Science Foundation of Hebei Province(No.E2019502199)。
文摘Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles to form the p-n heterojunction(Co_(3)O_(4)/TiO_(2)) to degrade acetaminophen(ACE) through photocatalytic activation of sulfite.Specifically,X-ray photoelectron spectroscopy analysis and theoretical calculations provide compelling evidence of electron transfer from Co_(3)O_(4) to TiO_(2) at the heterointerface.The interfacial electron redistribution of Co_(3)O_(4)/TiO_(2) tunes the adsorption energy of HSO_(3)^(-)/SO_(3)^(2-) in sulfite activation process for enhanced the catalytic activity.Owing to its unique heterointerface,the degradation efficiency of ACE reached 96.78%within 10 min.The predominant active radicals were identified as ·OH,h^(+),and SO_(x)^(·-) through radical quenching experiments and electron spin resonance capture.Besides,the possible degradation pathway was deduced by monitoring the generated intermediate products.Thereafter,the enhanced roles of well-engineered compositing interface in photocatalytic activation of sulfite for complete degradation of ACE were unveiled that it can improve light absorption ability,facilitate the generation of active species,and optimize reactive pathways.Considering that sulfite is a waste from flue gas desulfurization process,the photocatalytic activation of sulfite system will open up new avenues of beneficial use of air pollutants for the removal of pharmaceutical wastewater.
基金supported by the National Natural Science Foundation of China(No.51978542)Special Project of the Central Committee Guides Local Science and Technology Development of Hubei Province(No.2019ZYYD073)
文摘Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparticles embedded in nitrogen-doped graphite layers(Co@NC),were used to activate SO32−for removal of Methyl Orange in aqueous solution.The Co@NC catalysts were synthesized via pyrolysis of Co^(2+)-based metal-organic framework(Co-MOF),where CoO was firstly formed at 400℃ and then partially reduced to Co nanoparticles embedded in carbon layers at 800℃.The Co@NC catalysts were more active than other cobaltbased catalysts such as Co^(2+),Co_(3)O_(4) and CoFe_(2)O_(4),due to the synergistic effect of metallic Co and CoxOy.A series of chain reaction between Co species and dissolved oxygen was established,with the production and transformation of SO_(3)•−,SO_(5)^(2−),and subsequent active radicals SO_(4)•−and HO•.In addition,HCO_(3)−was found to play a key role in the reaction by complexing with Co species on the surface of the catalysts.The results provide a new promising strategy by using the Co@NC catalyst for SO3_(2)−oxidation to promote organic pollutants degradation.
基金financially-supported by the National Natural Science Foundation of China(Nos.21677055,22006045 and 21407052)the National Key Technical Research and Development Program of China(No.2019YFC1805204)+1 种基金Leading Plan for Scientific and Technological Innovation of High-tech Industries of Hunan Province(No.2021GK4060)the Fundamental Research Funds for the Central Universities,HUST(No.2017KFXKJC004).
文摘Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.
基金financially supported by the National Natural Science Foundation of China(No.22178395)the Scientific Research Fund of Hunan Provincial Education Department of China(20B104)
文摘Rapid,selective,and quantitative profiling of SO_(3)^(2-)is a prerequisite for investigating its effect on different physiopathological processes.To address this challenge,our team prepared a ratiometric fluorescent probe HBTCS,based on 4-(benzothiazol-2-yl)-3-hydroxybenzaldehyde for specific detection of SO_(3)^(2-)under a singlewavelength excitation.The solution of probe HBTC-S itself exhibited orange fluorescence(λ_(em)=614 nm),and became green fluorescent(λ_(em)=471 nm)after the addition of SO_(3)^(2-).The vitro experiments suggested that the probe displayed high sensitivity,excellent selectivity,and a low detection limit(0.15μM).Moreover,probe HBTC-S was successfully applied for qualitative and quantitative monitoring of SO_(3)^(2-)in realistic samples and living HeLa cells in a ratiometric manner.
基金supported by the National Natural Science Foundation of China(No.21307057)the Natural Science Foundation of Jiangsu Province(No.BK20130577)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(SRFDP,No.20130091120014)the Fundamental Research Funds for the Central Universities(No.20620140128)
文摘Halogenated aromatic compounds have attracted increasing concerns due to their toxicity and persistency in the environment, and dehalogenation is one of the promising treatment and detoxification methods. Herein, we systematically studied the debromination efficiency and mechanism of para-bromophenol(4-BP) by a recently developed UV/sulfite process. 4-BP underwent rapid degradation with the kinetics accelerated with the increasing sulfite concentration, pH(6.1–10) and temperature, whereas inhibited by dissolved oxygen and organic solvents. The apparent activation energy was estimated to be 27.8 kJ/mol. The degradation mechanism and pathways of 4-BP were explored by employing N_2O and nitrate as the electron scavengers and liquid chromatography/mass spectrometry to identify the intermediates. 4-BP degradation proceeded via at least two pathways including direct photolysis and hydrated electron-induced debromination. The contributions of both pathways were distinguished by quantifying the quantum yields of 4-BP via direct photolysis and hydrated electron production in the system. 4-BP could be readily completely debrominated with all the substituted Br released as Br-, and the degradation pathways were also proposed. This study would shed new light on the efficient dehalogenation of brominated aromatics by using the UV/sulfite process.
基金supported by the National Natural Science Foundation of China(No.81873079)。
文摘One-sixth of the currently known natural products containα,β-unsaturated carbonyl groups.Our previous studies reported a rare C-sulfonate metabolic pathway.Sulfonate groups were linked to theβ-carbon ofα,β-unsaturated carbonyl-based natural compounds through this pathway.However,the mechanism of this type of metabolism is still not fully understood,especially whether it is formed through enzyme-mediated biotransformation or direct sulfite addition.In this work,the enzyme-mediated and non-enzymatic pathways were studied.First,the sulfite content in rat intestine was determined by LC-MS/MS.The results showed that the amount of sulfite in rat intestinal contents was from 41.5 to 383μg·g^(-1),whereas the amount of sulfite in rat feed was lower than the lower limit of quantitation(20μg·g^(-1)).Second,the reaction kinetics of sulfite-andrographolide reactions in phosphate buffer solutions(pH 6-8)was studied.The half-lives of andrographolide ranged from minutes to hours.This was suggested that the C-sulfonate reaction of andrographolide was very fast.Third,the C-sulfonate metabolites of andrographolide were both detected when andrographolide and L-cysteine-S-conjugate andrographolide were incubated with the rat small intestine contents or sulfite,indicating that the sulfite amount in rat intestine contents was high enough to react with andrographolide,which assisted a significant portion of andrographolide metabolism.Finally,the comparison of andrographolide metabolite profiles among liver homogenate(with NADPH),liver S9(with NADPH),small intestine contents homogenate(with no NADPH),and sulfite solution incubations showed that the C-sulfonate metabolites were predominantly generated in the intestinal tract by non-enzymatic pathway.In summary,sulfite can serve as a substrate for C-sulfonate metabolism,and these results identified non-enzymatically nucleophilic addition as the potential mechanism for C-sulfonate metabolism of compounds containingα,β-unsaturated carbonyl moiety.
基金supported by the National Natural Science Foundation of China (Nos. 41772251, 41702267 and 41521001)the State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology (No. FSKLCCA1511)+1 种基金China Postdoctoral Science Foundation (No. 2017M612536)the “111” Project of the Ministry of Education of China
文摘The ligand-stabilized soluble Mn(Ⅲ) recognized as active intermediate can potentially mediate the attenuation of contaminants. In this study,the abiotic degradation behaviors of methyl parathion in the ligand stabilized Mn(Ⅲ)-sulfite system were investigated. The results showed that the yield of soluble Mn(Ⅲ) produced from the redox reaction of MnO2 and oxalic acid was dependent linearly on the dosage of Mn O2 and caused the decomposition of methyl parathion up to 50.1% in Mn(Ⅲ)-sulfite system after 30 minutes. The fitted pseudo-first-order reaction constants of methyl parathion degradation increased with the increasing of the amount of produced Mn(Ⅲ) but was not effected linearly by the addition of sulfite. Other ligands,including pyrophosphate and oxalic acid,acted as effective complexing agents to stabilize soluble Mn(Ⅲ),and exhibited competitive effect on methyl parathion degradation with sulfite. The formation of Mn(Ⅲ)-sulfite complexes is the critical step in the system to produce abundant reactive oxygen species identified as SO3·-to facilitate methyl parathion degradation. The hydrolysis and oxidation of methyl parathion were acknowledged as two primary transformation mechanisms in Mn(Ⅲ)-sulfite system. These findings indicate that naturally ligands-stabilized soluble Mn(Ⅲ) can be generated and could oxidatively decompose organophosphate pesticides such as methyl parathion.
基金Supported by the National Basic Research Program of China (Grant No. JK00020)the Doctor Research Fund from North China Electric Power University (Grant No. 200612008)the National High Technology Research and Development Program of China (Grant No. 2007AA061703)
文摘Oxidation of sulfite is an important process in wet flue gas desulfurization.Using highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus,the intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid was investigated under four dif-ferent conditions.The reaction order of the reagents and the activation energy were obtained.The re-sults indicate that water quality and light have no obvious effects on the reaction order and activation energy,but have an influence on the reaction rate constant.The mechanism of the intrinsic reaction is proposed.The results derived with this mechanism are in good agreement with the experimental re-sults.
文摘Accelerating the(NH_4)_(2)SO_(3) oxidation gives rise to the reclaiming of byproduct, while there are secondary environmental risks from reduction of the coexisted selenium species by sulfite. In this study, a bi-functional Co-SBA-15-SH, were synthesized through Co impregnation and sulfhydryl(-SH) decoration, which can simultaneously uptake Se and accelerate sulfite oxidation efficiently. Meanwhile, the adsorption kinetics and migration mechanism of Se species were revealed through characterization and density functional calculations, with maximum adsorption capacity of 223 mg/g. The inhibition of Se~0 re-emission and poisonous effect of Se on sulfite oxidation was also investigated. Using the findings of this study, the ammonia desulfurization can be improved by enabling purification of the byproduct and lowering the toxicity of effluent by removing toxic pollutants.
