All-solid-state lithium batteries(ASSLBs)based on sulfide solid electrolytes(SEs)are one of the most promising strategies for next-generation energy storage systems and electronic devices.However,the poor chemical/ele...All-solid-state lithium batteries(ASSLBs)based on sulfide solid electrolytes(SEs)are one of the most promising strategies for next-generation energy storage systems and electronic devices.However,the poor chemical/electrochemical stability of sulfide SEs with oxide cathode materials and high interfacial impedance,particularly due to physical contact failure,are the major limiting factors to the development of sulfide SEs in ASSLBs.Herein,the composite cathode of MOF-derived Fe_(7)S_(8)@C and Li_(6)PS_(5)Br fabricated by an infiltration method(IN-Fe_(7)S_(8))with dissoluble sulfide electrolyte(dissoluble SE)is reported.Dissoluble SE can easily infiltrate the porous sheet-type Fe_(7)S_(8)@C cathode to homogeneously contact with Fe_(7)S_(8)nanoparticles that are embedded in the surrounding carbon matrixes and form a fast ionic transport network.Benefiting from applying dissoluble SE and Fe_(7)S_(8)@C,the IN-Fe_(7)S_(8)-based cells displayed a reversible capacity of 510 mAh g^(-1)after 180 cycles at 0.045 mA cm^(-2)at 30℃.This work demonstrates a novel and practical method for the development of high-performance all-sulfide-based solid state batteries.展开更多
The kinetics of Cr（Ⅵ） reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe（Ⅱ） concentrations was examined using batch anaeroblc experimental systems at constant temperature. The r...The kinetics of Cr（Ⅵ） reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe（Ⅱ） concentrations was examined using batch anaeroblc experimental systems at constant temperature. The results showed that the reaction rate of Cr（Ⅵ） reduction was in the order of red soil 〈 yellow-brown soil 〈 chernozem and was proportional to the concentration of HCl-extractable iron in the soils. Dissolved and adsorbed iron in soil suspensions played an important role in accelerating Cr（Ⅵ） reduction. The reaction involved in the Cr（Ⅵ） reduction by Fe（Ⅱ） to produce Fe（ⅡI）, which was reduced to Fe（Ⅱ） again by sulfide, could represent the catalytic pathway until about 70% of the initially present Cr（Ⅵ） was reduced. The catalysis occurred because the one-step reduction of Cr（Ⅵ） by sulfide was slower than the two-step process consisting of rapid Cr（Ⅵ） reduction by Fe（Ⅱ） followed by Fe（Ⅲ） reduction by sulfide. In essence, Fe（Ⅱ）/Fe（Ⅲ） species shuttle electrons from sulfide to Cr（Ⅵ）, facilitating the reaction. The effect of iron, however, could be completely blocked by adding a strong Fe（Ⅱ）-complexing ligand, 1,10-phenanthroline, to the soil suspensions. In all the experiments, initial sulfide concentration was much higher than initial Cr（Ⅵ） concentration. The plots of In e[Cr（Ⅵ）] versus reaction time were linear up to approximately 70% of Cr（Ⅵ） reduction, suggesting a first-order reaction kinetics with respect to Cr（Ⅵ）. Elemental sulfur, the product of sulfide oxidation, was found to accelerate Cr（Ⅵ） reduction at a later stage of the reaction, resulting in deviation from linearity for the In c[Cr（Ⅵ）] versus time plots.展开更多
Iron sulfide minerals are widely distributed, of which characteristics had the identification significance of formation environment. Previously, there were more research on iron sulfide minerals under hydrothermal con...Iron sulfide minerals are widely distributed, of which characteristics had the identification significance of formation environment. Previously, there were more research on iron sulfide minerals under hydrothermal condition, and few studies under volcanism formation condition. To simulate volcanic mineralization, the study of different temperature from 250 to 410℃ , different iron sulfur ratio from Fe:S=2∶1 to 1∶8, and two different sources of iron, reduced iron powder (Fe) and ferrous sulfide (FeS), on iron sulfide mineral evolution was investigated under thermal sulfurization condition. By using scanning electron microscopy (SEM), X-ray diffraction (XRD) and other methods, the morphology, composition and structural characteristics of the products were observed and analyzed.展开更多
Cadmium(Cd),lead(Pb),and hexavalent chromium(Cr(Ⅵ)) are often found in soils and water affected by metal smelting,chemical manufacturing,and electroplating.In this study,synthetic iron sulfide nanoparticles(FeS NPs) ...Cadmium(Cd),lead(Pb),and hexavalent chromium(Cr(Ⅵ)) are often found in soils and water affected by metal smelting,chemical manufacturing,and electroplating.In this study,synthetic iron sulfide nanoparticles(FeS NPs) were stabilized with carboxymethyl cellulose(CMC) and utilized to remove Cr(Ⅵ),Cd,and Pb from an aqueous solution.Batch experiments,a Visual MINTEQ model,scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectrometer(XPS) analysis were used to determine the removal efficiencies,influencing factors,and mechanisms.The FeS NP suspension simultaneously removed Cr(Ⅵ),Cd,and Pb from an aqueous solution.The concentrations of Cr(Ⅵ),Cd,and Pb decreased from 50,10,and 50 mg·L^(-1) to 2.5,0.1,and 0.1 mg·L^(-1),respectively.The removal capacities were up to 418,96,and 585 mg per gram of stabilized FeS NPs,respectively.The acidic conditions significantly favored the removal of aqueous Cr(Ⅵ) while the alkaline conditions favored the removal of Cd and Pb.Oxygen slightly inhibited the removal of Cr(Ⅵ),but it had no significant influence on the removal of Cd and Pb.A potential mechanism was proposed for the simultaneous removal of Cr(Ⅵ),Cd,and Pb using FeS NPs.The interactions of the three heavy metals involved a cationic bridging effect on Cr(Ⅵ) by Cd,an enhanced adsorption effect on Cd by [Cr,Fe](OH)_3,precipitation of PbCrO_4,and transformation of PbCrO_4 to PbS.Therefore,FeS NPs have a high potential for use in the simultaneous removal of Cr(Ⅵ),Cd,and Pb from contaminated aqueous solutions.展开更多
Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced...Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced.Moreover,its adverse influences upon environment were summarized,including direct contribution to deficiency of dissolved oxygen in water,association with eutrophication in water-bodies and impact on geochemical sulfur cycle.Since conventional chemical analysis for iron sulfide has several disadvantages,new technique for rapid determination of iron sulfide on-line was prospected.展开更多
Presence of iron and manganese in water not only affects the organoleptic properties of water, but also can cause a number of problems in drinking water treatments. Their removal in drinking water preparation processe...Presence of iron and manganese in water not only affects the organoleptic properties of water, but also can cause a number of problems in drinking water treatments. Their removal in drinking water preparation processes becomes more complicated in the presence of hydrogen sulfide and ammonia in water. There are certain commercialized products at the market that are used for removal of manganese, iron and ammonia, but it is of crucial importance to establish an appropriate order of removal in the technological process during drinking water treatment. Through the various combinations of commercialized filtration media, the removal of iron, manganese, hydrogen sulfide and ammonia, was being examined and on the basis of obtained results their effectiveness was estimated. Research results have shown that hydrogen sulfide is pollutant that causes problems during the adsorption in removing manganes. Ammonia, which is bonded to hydrogen sulphide influences the volume of treated water when it comes to removing the iron and manganese. Decrease in the concentration of hydrogen sulfide at the entrance to Filtersorb FMH for four times, has led to an increase in the volume of treated water in the amount of two times, followed by the breakthrough point of concentration of manganese. For complete usage capacity of commercialized products for the removal of these pollutants, finding their mutual bond in compounds which are present in the water, is of the importance.展开更多
Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study propo...Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study proposed a new process involving sulfidation roasting, magnetic separation and flotation to recover zinc and iron in ZLR. Through sulfidation roasting of ZLR with pyrite, zinc and iron were converted into ZnS and Fe3 O4. The effects of pyrite dosage, roasting temperature and roasting time on the sulfidation of zinc in ZLR were investigated. The results showed that the sulfidation percentage of zinc reached 91.8% under the optimum condition. Besides, it was found that ball-milling was favorable for the separation and recovery of zinc and iron in sulfidation products. After ball-milling pretreatment, iron and zinc were enriched from sulfidation products by magnetic separation and flotation. The grade of iron in magnetic concentrates was 52.3% and the grade of zinc in flotation concentrates was 31.7%, which realized the recovery of resources.展开更多
The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was fas...The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Fe0.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.展开更多
Fe–S compounds with hexagonal crystal structure are potential hydrogen permeation barrier during H2S corrosion. Hexagonal system Fe–S films were prepared on carbon steel through corrosion and CVD deposition, and the...Fe–S compounds with hexagonal crystal structure are potential hydrogen permeation barrier during H2S corrosion. Hexagonal system Fe–S films were prepared on carbon steel through corrosion and CVD deposition, and the barrier effect of different Fe–S films on hydrogen permeation was tested using electrochemical hydrogen permeation method. After that, the electrical properties of Fe–S compound during phase transformation were measured using thermoelectric measurement system. Results show that the mackinawite has no obvious barrier effect on hydrogen penetration, as a p-type semiconductor, and pyrrhotite (including troilite) has obvious barrier effect on hydrogen penetration,as an n-type semiconductor. Hydrogen permeation tests showed peak permeation performance when the surface was deposited with a continuous film of pyrrhotite (Fe_(1–x)S) and troilite. The FeS compounds suppressed hydrogen permeation by the promotion of the hydrogen evolution reaction, semiconducting inversion from p-to n-type, and the migration of ions at the interface.展开更多
In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD ...In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD concentration was 12000mg/L. However, A large number of ferric sludge (SS=8.724g/L) would be produced after the Fenton oxidation of the wastewater and must be disposed appropriately. A novel process for Fenton sludge reused by low-cost ferrous sulfide (FeS) was also investi-gated. Experimental results show that the Fenton sludge could be reduced to produce a certain amount of Fe2+ in the acidic mixed liquor by ferrous sulfide. This mixed liquor from Fenton sludge could be used as the new catalyst in the Fenton process and was also highly effective for the NPEOs wastewater treatment. The residual ferrous sulfide from the mixed liquor could be used for the next batch of the展开更多
Sulfated zero-valent iron(SZVI)has shown promising applications in wastewater treatment.However,the rapid decline in the reactivity of SZVI with time limits its real practice.To mediate this problem,partial aging was ...Sulfated zero-valent iron(SZVI)has shown promising applications in wastewater treatment.However,the rapid decline in the reactivity of SZVI with time limits its real practice.To mediate this problem,partial aging was proposed to improve the reactive durability of SZVI.Taking Cr(VI)as the target contaminant,we found that the aged ZVI(AZVI)gradually lost reactivity as aging time increased from 0.5 to 2 d.Counter-intuitively,the partially aged SZVI(ASZVI)showed greater reactivity than SZVI when exposed to oxygenated water for a period ranging from 0.5 to 14 d.In addition,the ASZVI with 0.5 d of aging time(ASZVI-0.5)not only maintained reactivity in successive runs but also increased the Cr(VI)removal capacity from 9.1 mg/g by SZVI to 19.1 mg/g by ASZVI-0.5.Correlation analysis further revealed that the electron transfer from the Fe0 core to the shell was mediated by the conductive FeS and FeS2 in the subshell of ASZVI.Meanwhile,the lepidocrocite and magnetite on the surface of ASZVI facilitated Cr(VI)adsorption and subsequent electron transfer for Cr(VI)reduction.Moreover,the iron(hydr)oxide shell could retain the conductive FeS and FeS2 in the subshell,allowing ASZVI to reduce Cr(VI)efficiently and sustainably.In general,partial aging can enhance the reactive durability of ZVI when coupled with sulfidation and this synergistic effect will be beneficial to the application of SZVI-based technology for wastewater treatment.展开更多
Sulfidation of zero-valent iron(ZVI)has attracted broad attention in recent years for improving the sequestration of contaminants from water.However,sulfidated ZVI(S-ZVI)is mostly synthesized in the aqueous phase,whic...Sulfidation of zero-valent iron(ZVI)has attracted broad attention in recent years for improving the sequestration of contaminants from water.However,sulfidated ZVI(S-ZVI)is mostly synthesized in the aqueous phase,which usually causes the formation of a thick iron oxide layer on the ZVI surface and hinders the efficient electron transfer to the contaminants.In this study,an alcohothermal strategy was employed for S-ZVI synthesis by the one-step reaction of iron powder with elemental sulfur.It is found that ferrous sulfide(FeS)with high purity and fine crystallization was formed on the ZVI surface,which is extremely favorable for electron transfer.Cr(Ⅵ)removal experiments confirm that the rate constant of SZVI synthesized by the alcohothermal method was 267.1-and 5.4-fold higher than those of un-sulfidated ZVI and aqueous-phase synthesized S-ZVI,respectively.Systematic characterizations proved that Cr(Ⅵ)was reduced and co-precipitated on S-ZVI in the form of a Fe(Ⅲ)/Cr(Ⅲ)/Cr(Ⅵ)composite,suggesting its environmental benignancy.展开更多
基金supported by the Guangdong“Pearl River Talents Plan”(no.2017GC010218)R&D Program in Key Areas of Guangdong Province(no.2020B0101030005)+2 种基金Guangdong Basic and Applied Basic Research Foundation(nos.2020B15151200492021A1515010153)the National Natural Science Foundation of China(no.NSFC51621001).
文摘All-solid-state lithium batteries(ASSLBs)based on sulfide solid electrolytes(SEs)are one of the most promising strategies for next-generation energy storage systems and electronic devices.However,the poor chemical/electrochemical stability of sulfide SEs with oxide cathode materials and high interfacial impedance,particularly due to physical contact failure,are the major limiting factors to the development of sulfide SEs in ASSLBs.Herein,the composite cathode of MOF-derived Fe_(7)S_(8)@C and Li_(6)PS_(5)Br fabricated by an infiltration method(IN-Fe_(7)S_(8))with dissoluble sulfide electrolyte(dissoluble SE)is reported.Dissoluble SE can easily infiltrate the porous sheet-type Fe_(7)S_(8)@C cathode to homogeneously contact with Fe_(7)S_(8)nanoparticles that are embedded in the surrounding carbon matrixes and form a fast ionic transport network.Benefiting from applying dissoluble SE and Fe_(7)S_(8)@C,the IN-Fe_(7)S_(8)-based cells displayed a reversible capacity of 510 mAh g^(-1)after 180 cycles at 0.045 mA cm^(-2)at 30℃.This work demonstrates a novel and practical method for the development of high-performance all-sulfide-based solid state batteries.
文摘The kinetics of Cr（Ⅵ） reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe（Ⅱ） concentrations was examined using batch anaeroblc experimental systems at constant temperature. The results showed that the reaction rate of Cr（Ⅵ） reduction was in the order of red soil 〈 yellow-brown soil 〈 chernozem and was proportional to the concentration of HCl-extractable iron in the soils. Dissolved and adsorbed iron in soil suspensions played an important role in accelerating Cr（Ⅵ） reduction. The reaction involved in the Cr（Ⅵ） reduction by Fe（Ⅱ） to produce Fe（ⅡI）, which was reduced to Fe（Ⅱ） again by sulfide, could represent the catalytic pathway until about 70% of the initially present Cr（Ⅵ） was reduced. The catalysis occurred because the one-step reduction of Cr（Ⅵ） by sulfide was slower than the two-step process consisting of rapid Cr（Ⅵ） reduction by Fe（Ⅱ） followed by Fe（Ⅲ） reduction by sulfide. In essence, Fe（Ⅱ）/Fe（Ⅲ） species shuttle electrons from sulfide to Cr（Ⅵ）, facilitating the reaction. The effect of iron, however, could be completely blocked by adding a strong Fe（Ⅱ）-complexing ligand, 1,10-phenanthroline, to the soil suspensions. In all the experiments, initial sulfide concentration was much higher than initial Cr（Ⅵ） concentration. The plots of In e[Cr（Ⅵ）] versus reaction time were linear up to approximately 70% of Cr（Ⅵ） reduction, suggesting a first-order reaction kinetics with respect to Cr（Ⅵ）. Elemental sulfur, the product of sulfide oxidation, was found to accelerate Cr（Ⅵ） reduction at a later stage of the reaction, resulting in deviation from linearity for the In c[Cr（Ⅵ）] versus time plots.
基金Supported by National Natural Science Foundation (Grant No.:40872045 41172047)The Opening Project of Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education (12zxgk01)
文摘Iron sulfide minerals are widely distributed, of which characteristics had the identification significance of formation environment. Previously, there were more research on iron sulfide minerals under hydrothermal condition, and few studies under volcanism formation condition. To simulate volcanic mineralization, the study of different temperature from 250 to 410℃ , different iron sulfur ratio from Fe:S=2∶1 to 1∶8, and two different sources of iron, reduced iron powder (Fe) and ferrous sulfide (FeS), on iron sulfide mineral evolution was investigated under thermal sulfurization condition. By using scanning electron microscopy (SEM), X-ray diffraction (XRD) and other methods, the morphology, composition and structural characteristics of the products were observed and analyzed.
基金supported by the National Natural Science Foundation of China (51778084)the National key Research&Development program of China (2018YFC1800305)+2 种基金the Chongqing Ecology and Environment Bureau (2019-128)the Sichuan Science and Technology Program (2019YFSY0005)the Large Instruments Open Foundation of Chongqing University (201903150051)。
文摘Cadmium(Cd),lead(Pb),and hexavalent chromium(Cr(Ⅵ)) are often found in soils and water affected by metal smelting,chemical manufacturing,and electroplating.In this study,synthetic iron sulfide nanoparticles(FeS NPs) were stabilized with carboxymethyl cellulose(CMC) and utilized to remove Cr(Ⅵ),Cd,and Pb from an aqueous solution.Batch experiments,a Visual MINTEQ model,scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectrometer(XPS) analysis were used to determine the removal efficiencies,influencing factors,and mechanisms.The FeS NP suspension simultaneously removed Cr(Ⅵ),Cd,and Pb from an aqueous solution.The concentrations of Cr(Ⅵ),Cd,and Pb decreased from 50,10,and 50 mg·L^(-1) to 2.5,0.1,and 0.1 mg·L^(-1),respectively.The removal capacities were up to 418,96,and 585 mg per gram of stabilized FeS NPs,respectively.The acidic conditions significantly favored the removal of aqueous Cr(Ⅵ) while the alkaline conditions favored the removal of Cd and Pb.Oxygen slightly inhibited the removal of Cr(Ⅵ),but it had no significant influence on the removal of Cd and Pb.A potential mechanism was proposed for the simultaneous removal of Cr(Ⅵ),Cd,and Pb using FeS NPs.The interactions of the three heavy metals involved a cationic bridging effect on Cr(Ⅵ) by Cd,an enhanced adsorption effect on Cd by [Cr,Fe](OH)_3,precipitation of PbCrO_4,and transformation of PbCrO_4 to PbS.Therefore,FeS NPs have a high potential for use in the simultaneous removal of Cr(Ⅵ),Cd,and Pb from contaminated aqueous solutions.
基金Supported by Homecoming Foundation of Heilongjiang Province(LC06C04)Researcher Overseas Foundation of the Department of Education of Heilongjiang Province(1152hq19)
文摘Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced.Moreover,its adverse influences upon environment were summarized,including direct contribution to deficiency of dissolved oxygen in water,association with eutrophication in water-bodies and impact on geochemical sulfur cycle.Since conventional chemical analysis for iron sulfide has several disadvantages,new technique for rapid determination of iron sulfide on-line was prospected.
基金supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia,Project Number OI 176018.
文摘Presence of iron and manganese in water not only affects the organoleptic properties of water, but also can cause a number of problems in drinking water treatments. Their removal in drinking water preparation processes becomes more complicated in the presence of hydrogen sulfide and ammonia in water. There are certain commercialized products at the market that are used for removal of manganese, iron and ammonia, but it is of crucial importance to establish an appropriate order of removal in the technological process during drinking water treatment. Through the various combinations of commercialized filtration media, the removal of iron, manganese, hydrogen sulfide and ammonia, was being examined and on the basis of obtained results their effectiveness was estimated. Research results have shown that hydrogen sulfide is pollutant that causes problems during the adsorption in removing manganes. Ammonia, which is bonded to hydrogen sulphide influences the volume of treated water when it comes to removing the iron and manganese. Decrease in the concentration of hydrogen sulfide at the entrance to Filtersorb FMH for four times, has led to an increase in the volume of treated water in the amount of two times, followed by the breakthrough point of concentration of manganese. For complete usage capacity of commercialized products for the removal of these pollutants, finding their mutual bond in compounds which are present in the water, is of the importance.
基金Project(2018YFC1900305)supported by the National Key R&D Program of ChinaProject(51825403)supported by the National Science Foundation for Distinguished Young Scholars,China+1 种基金Projects(51634010,51474247,51904354)supported by the National Natural Science Foundation of ChinaProject(2019SK2291)supported by the Key Research and Development Program of Hunan Province,China。
文摘Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study proposed a new process involving sulfidation roasting, magnetic separation and flotation to recover zinc and iron in ZLR. Through sulfidation roasting of ZLR with pyrite, zinc and iron were converted into ZnS and Fe3 O4. The effects of pyrite dosage, roasting temperature and roasting time on the sulfidation of zinc in ZLR were investigated. The results showed that the sulfidation percentage of zinc reached 91.8% under the optimum condition. Besides, it was found that ball-milling was favorable for the separation and recovery of zinc and iron in sulfidation products. After ball-milling pretreatment, iron and zinc were enriched from sulfidation products by magnetic separation and flotation. The grade of iron in magnetic concentrates was 52.3% and the grade of zinc in flotation concentrates was 31.7%, which realized the recovery of resources.
文摘The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Fe0.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.
基金financailly supported by the National Natural Science Foundation of China (Nos.52275198 and 51805292)the Beijing Natural Science Foundation,China(No.2202020)the Tribology Science Fund of State Key Laboratory of Tribology,China (No.SKLT2022B11)。
文摘Fe–S compounds with hexagonal crystal structure are potential hydrogen permeation barrier during H2S corrosion. Hexagonal system Fe–S films were prepared on carbon steel through corrosion and CVD deposition, and the barrier effect of different Fe–S films on hydrogen permeation was tested using electrochemical hydrogen permeation method. After that, the electrical properties of Fe–S compound during phase transformation were measured using thermoelectric measurement system. Results show that the mackinawite has no obvious barrier effect on hydrogen penetration, as a p-type semiconductor, and pyrrhotite (including troilite) has obvious barrier effect on hydrogen penetration,as an n-type semiconductor. Hydrogen permeation tests showed peak permeation performance when the surface was deposited with a continuous film of pyrrhotite (Fe_(1–x)S) and troilite. The FeS compounds suppressed hydrogen permeation by the promotion of the hydrogen evolution reaction, semiconducting inversion from p-to n-type, and the migration of ions at the interface.
文摘In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD concentration was 12000mg/L. However, A large number of ferric sludge (SS=8.724g/L) would be produced after the Fenton oxidation of the wastewater and must be disposed appropriately. A novel process for Fenton sludge reused by low-cost ferrous sulfide (FeS) was also investi-gated. Experimental results show that the Fenton sludge could be reduced to produce a certain amount of Fe2+ in the acidic mixed liquor by ferrous sulfide. This mixed liquor from Fenton sludge could be used as the new catalyst in the Fenton process and was also highly effective for the NPEOs wastewater treatment. The residual ferrous sulfide from the mixed liquor could be used for the next batch of the
基金supported by the National Key R&D Program of China(No.2021YFA1201701)the National Natural Science Foundation of China(No.22025601)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_0495).
文摘Sulfated zero-valent iron(SZVI)has shown promising applications in wastewater treatment.However,the rapid decline in the reactivity of SZVI with time limits its real practice.To mediate this problem,partial aging was proposed to improve the reactive durability of SZVI.Taking Cr(VI)as the target contaminant,we found that the aged ZVI(AZVI)gradually lost reactivity as aging time increased from 0.5 to 2 d.Counter-intuitively,the partially aged SZVI(ASZVI)showed greater reactivity than SZVI when exposed to oxygenated water for a period ranging from 0.5 to 14 d.In addition,the ASZVI with 0.5 d of aging time(ASZVI-0.5)not only maintained reactivity in successive runs but also increased the Cr(VI)removal capacity from 9.1 mg/g by SZVI to 19.1 mg/g by ASZVI-0.5.Correlation analysis further revealed that the electron transfer from the Fe0 core to the shell was mediated by the conductive FeS and FeS2 in the subshell of ASZVI.Meanwhile,the lepidocrocite and magnetite on the surface of ASZVI facilitated Cr(VI)adsorption and subsequent electron transfer for Cr(VI)reduction.Moreover,the iron(hydr)oxide shell could retain the conductive FeS and FeS2 in the subshell,allowing ASZVI to reduce Cr(VI)efficiently and sustainably.In general,partial aging can enhance the reactive durability of ZVI when coupled with sulfidation and this synergistic effect will be beneficial to the application of SZVI-based technology for wastewater treatment.
基金the National Key Research and Development Program of China(No.2019YFC1806203)for financial support。
文摘Sulfidation of zero-valent iron(ZVI)has attracted broad attention in recent years for improving the sequestration of contaminants from water.However,sulfidated ZVI(S-ZVI)is mostly synthesized in the aqueous phase,which usually causes the formation of a thick iron oxide layer on the ZVI surface and hinders the efficient electron transfer to the contaminants.In this study,an alcohothermal strategy was employed for S-ZVI synthesis by the one-step reaction of iron powder with elemental sulfur.It is found that ferrous sulfide(FeS)with high purity and fine crystallization was formed on the ZVI surface,which is extremely favorable for electron transfer.Cr(Ⅵ)removal experiments confirm that the rate constant of SZVI synthesized by the alcohothermal method was 267.1-and 5.4-fold higher than those of un-sulfidated ZVI and aqueous-phase synthesized S-ZVI,respectively.Systematic characterizations proved that Cr(Ⅵ)was reduced and co-precipitated on S-ZVI in the form of a Fe(Ⅲ)/Cr(Ⅲ)/Cr(Ⅵ)composite,suggesting its environmental benignancy.
