Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after tr...Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after treatment with conventional disinfectants. Ultraviolet (UV) technology has been seen growth in application to disinfect the water. However, UV method alone is not adequate to degrade ARGs in water. Researchers are investigating the combination of UV with other oxidants (chlorine, hydrogen peroxide (H2O2), peroxymonosulfate (PMS), and photocatalysts) to harness the high reactivity of produced reactive species (C1-, C1O -, Cl2-,-OH, and SO4-_) in such processes with constituents of cell (e.g., deoxyribonucleic acid (DNA) and its components) in order to increase the degradation efficiency of ARGs. This paper briefly reviews the current status of different UV-based treatments (UV/chlorination, UV/H2O2, UV/PMS, and UV-photocatalysis) to degrade ARGs and to control horizontal gene transfer (HGT) in water. The review also provides discussion on the mechanism of degradation of ARGs and application of q-PCR and gel electrophoresis to obtain insights of the fate of ARGs during UV-based treatment processes.展开更多
Interest in the development of inorganic polymerized coagulants is growing; however, there are only limited studies on the synthesis of polytitanium coagulants, which are expected to exhibit improved coagulation effic...Interest in the development of inorganic polymerized coagulants is growing; however, there are only limited studies on the synthesis of polytitanium coagulants, which are expected to exhibit improved coagulation efficiency with better floc properties. This study presents the synthesis of polytitanium sulfate（PTS） for potential application in water purification,followed by characterization of PTS flocs and titanium species detection. Stable PTS solutions were successfully synthesized and standard jar tests were conducted to evaluate their coagulation efficiency. Electrospray ionization time-of-flight mass spectrometry（ESI-TOF-MS） speciation analysis revealed that a variety of mononuclear and polynuclear complexes were formed in PTS solution, indicating the polymeric nature of the synthesized coagulant. Floc characteristics were studied through on-line monitoring of floc size using a laser diffraction particle size analyzer. Results showed that PTS had a comparable or in some cases even higher organic matter and particulate removal efficiency than Ti（SO4）2.The effluent p H after PTS coagulation significantly improved toward desirable values closer to neutral p H. Properties of flocs formed by PTS were significantly improved in terms of floc size, growth rate and structure. This study showed that PTS could be an efficient and promising coagulant for water purification, with the additional benefit that its coagulated sludge can be used to recover valuable TiO2 nanoparticles for various commercial applications.展开更多
Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate co...Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate concentrations during haze episodes,indicating that there are still missing mechanisms not considered by the models.Despite recent good progress in understanding the missing sulfate sources,knowledge on different sulfate formation pathways during polluted periods still involves large uncertainties and the dominant mechanism is under heated debate,calling for more field,laboratory,and modeling work.Here,we review the traditional sulfate formation mechanisms in cloud water and also discuss the potential factors affecting multiphase S(Ⅳ)oxidation.Then recent progress in multiphase S(Ⅳ)oxidation mechanisms is summarized.Sulfate formation rates by different prevailing oxidation pathways under typical winter-haze conditions are also calculated and compared.Based on the literature reviewed,we put forward control of the atmospheric oxidation capacity as a means to abate sulfate aerosol pollution.Finally,we conclude with a concise set of research priorities for improving our understanding of sulfate formation mechanisms during polluted periods.展开更多
Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of ...Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of hydrogen sulfide(SOH_(2)S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly solution.Due to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH_(2)S;however,rapid deactivation has remained a significant drawback.The causes of iron oxide-based catalysts deactivation mechanisms in SOH_(2)S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this review.By focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH_(2)S.展开更多
Effectively strengthening the surface sulfidation is essential for recovering hemimorphite by froth flotation.In this work,inductively coupled plasma optical emission spectrometer(ICP-OES)measurements,Visual MINTEQ ca...Effectively strengthening the surface sulfidation is essential for recovering hemimorphite by froth flotation.In this work,inductively coupled plasma optical emission spectrometer(ICP-OES)measurements,Visual MINTEQ calculation,X-ray photoelectron spectroscopy(XPS)analysis,time of flight secondary ion mass spectrometry(ToF-SIMS)analysis,and micro-flotation experiments were explored to systematically investigate the effect of ammonium sulfate((NH_(4))_(2)SO_(4))on the formation of zinc sulfide species on hemimorphite surface and its role in sulfidation flotation.The results showed that(NH_(4))_(2)SO_(4)exhibited a positive influence on hemimorphite sulfidation flotation.It was ascribed to the number of zinc components in the form of Zn^(2+)and[Zn(NH_(3))_(i)]^(2+)(i=1–4)increased in the flotation system after hemimorphite treatment with(NH_(4))_(2)SO_(4),which was beneficial to its interaction with sulfur species in solution,resulting in a dense and stable zinc sulfide layer generated on the hemimorphite surface.[Zn(NH_(3))_(i)]^(2+)participated in the sulfidation reaction of hemimorphite as a transition state.In addition the sulfidation reaction of hemimorphite was accelerated by(NH_(4))_(2)SO_(4).Thus,(NH_(4))_(2)SO_(4)presents a vital role in promoting the sulfidation of hemimorphite.展开更多
Intermolecular geometries and energies of the dimers formed between simple aromatic hydrocarbons （benzene, toluene and naphthalene） and sulfate species （sulfuric acid, bisulfate and sulfate） were studied by densit...Intermolecular geometries and energies of the dimers formed between simple aromatic hydrocarbons （benzene, toluene and naphthalene） and sulfate species （sulfuric acid, bisulfate and sulfate） were studied by density functional theory. The AH：H2SO4 complexes were determined by the OH-π H-bond, with H2SO4 acting as the H-bond donor and AHs as the aeeeptor. However, the AHs：HSO4- and AHs：SO4^2- complexes were established by the H-bond, with AHs serving as acid and HSO4 or SO4^2- as alkali. The atmospheric implications of those complexes were strongly supported by their considerable binding energies.展开更多
Transition metal-based bimetallic oxides can effectively activate peroxymonosulfate(PMS) for the degradation of organic contaminants, which may be attributed to the enhanced electron transfer efficiency between transi...Transition metal-based bimetallic oxides can effectively activate peroxymonosulfate(PMS) for the degradation of organic contaminants, which may be attributed to the enhanced electron transfer efficiency between transition metals. Here, we investigated the high-efficiency catalytic activation reaction of PMS on a well-defined bimetallic Fe-Mn nanocomposite(BFMN) catalyst. The surface topography and chemical information of BFMN were simultaneously mapped with nanoscale resolution. Rhodamine B(Rh B, as a model pollutant) was used to evaluate the oxidation activity of PMS activation system. The maximum absorption peak of Rh B obviously blue shifted from 554 nm to 501 nm, and decreased sharply to disappear completely within 60 min. The removal performance is better than most of the reported single transition metal oxide. X-ray photoelectron spectroscopy(XPS) imaging of the BFMN electronic structure after catalytic activation confirmed that the accelerated internal electron transfer is mainly caused by the synergy effect of Mn and Fe sites at the catalysis boundary. The outstanding ability of BFMN for PMS chemical adsorption and activation may attribute to the enhanced covalency and reactivity of Mn-O. These results of this study can advance understandings on the origins of bimetallic oxides activity for PMS activation and developing the efficient metal oxide catalysts in real practice.展开更多
Polyferric silicate sulfate （PFSS） with high concentration was prepared using the composite-poly method. The coagulation properties and mechanisms of this new complex were probed using TEM, Fe-Ferron timed complex-c...Polyferric silicate sulfate （PFSS） with high concentration was prepared using the composite-poly method. The coagulation properties and mechanisms of this new complex were probed using TEM, Fe-Ferron timed complex-colorimetric method, and infrared spectrum method. The results showed that the flocculating effect of polyferric silicate sulfate had an advantage over polyferric sulfate （PFS）, as the optimum coagulation effect could be obtained when the Si/Fe mole ratio was 0.75 in accordance with its macrostructure of PFSS. According to the Fe-Ferron timed complex-colorimetric method, the Si species was mainly Sic, whereas, the Fe species were Fea and Fec in the copolymerization system. The infrared spectra indicated that the structure of these new flocculants was formed by polymers, mainly by olation, which was different from polyferric sulfate, and the vibration of M-OH-M of around 1100 cm^-1, also proved that there existed Fe-OH-Fe and its polymers in some forms.展开更多
文摘Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after treatment with conventional disinfectants. Ultraviolet (UV) technology has been seen growth in application to disinfect the water. However, UV method alone is not adequate to degrade ARGs in water. Researchers are investigating the combination of UV with other oxidants (chlorine, hydrogen peroxide (H2O2), peroxymonosulfate (PMS), and photocatalysts) to harness the high reactivity of produced reactive species (C1-, C1O -, Cl2-,-OH, and SO4-_) in such processes with constituents of cell (e.g., deoxyribonucleic acid (DNA) and its components) in order to increase the degradation efficiency of ARGs. This paper briefly reviews the current status of different UV-based treatments (UV/chlorination, UV/H2O2, UV/PMS, and UV-photocatalysis) to degrade ARGs and to control horizontal gene transfer (HGT) in water. The review also provides discussion on the mechanism of degradation of ARGs and application of q-PCR and gel electrophoresis to obtain insights of the fate of ARGs during UV-based treatment processes.
基金supported by the National Natural Science Foundation of China(Nos.51278283 and 51508308)the China Postdoctoral Science Foundation(Nos.2014M560557 and2015T80722)+1 种基金the Tai Shan Scholar Foundation(No.ts201511003)Hong Kong Scholars Program
文摘Interest in the development of inorganic polymerized coagulants is growing; however, there are only limited studies on the synthesis of polytitanium coagulants, which are expected to exhibit improved coagulation efficiency with better floc properties. This study presents the synthesis of polytitanium sulfate（PTS） for potential application in water purification,followed by characterization of PTS flocs and titanium species detection. Stable PTS solutions were successfully synthesized and standard jar tests were conducted to evaluate their coagulation efficiency. Electrospray ionization time-of-flight mass spectrometry（ESI-TOF-MS） speciation analysis revealed that a variety of mononuclear and polynuclear complexes were formed in PTS solution, indicating the polymeric nature of the synthesized coagulant. Floc characteristics were studied through on-line monitoring of floc size using a laser diffraction particle size analyzer. Results showed that PTS had a comparable or in some cases even higher organic matter and particulate removal efficiency than Ti（SO4）2.The effluent p H after PTS coagulation significantly improved toward desirable values closer to neutral p H. Properties of flocs formed by PTS were significantly improved in terms of floc size, growth rate and structure. This study showed that PTS could be an efficient and promising coagulant for water purification, with the additional benefit that its coagulated sludge can be used to recover valuable TiO2 nanoparticles for various commercial applications.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214801)the China Postdoctoral Science Foundation(Nos.2021M700214 and 2022T150011)。
文摘Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate concentrations during haze episodes,indicating that there are still missing mechanisms not considered by the models.Despite recent good progress in understanding the missing sulfate sources,knowledge on different sulfate formation pathways during polluted periods still involves large uncertainties and the dominant mechanism is under heated debate,calling for more field,laboratory,and modeling work.Here,we review the traditional sulfate formation mechanisms in cloud water and also discuss the potential factors affecting multiphase S(Ⅳ)oxidation.Then recent progress in multiphase S(Ⅳ)oxidation mechanisms is summarized.Sulfate formation rates by different prevailing oxidation pathways under typical winter-haze conditions are also calculated and compared.Based on the literature reviewed,we put forward control of the atmospheric oxidation capacity as a means to abate sulfate aerosol pollution.Finally,we conclude with a concise set of research priorities for improving our understanding of sulfate formation mechanisms during polluted periods.
基金supported by Thailand Science Research and Innovation Fund Chulalongkorn University,Thailand(IND66210014)。
文摘Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low concentrations.Among various technologies,the selective oxidation of hydrogen sulfide(SOH_(2)S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly solution.Due to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH_(2)S;however,rapid deactivation has remained a significant drawback.The causes of iron oxide-based catalysts deactivation mechanisms in SOH_(2)S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this review.By focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH_(2)S.
基金Fundamental Research Funds for the Central Universities(No.2023YQTD03,2022JCCX HH09,2022YJSHH01)the Yueqi Outstanding Scholaraward of China University of Mining&Technology(Beijing)+3 种基金the National Natural Science Foundation of China(No.52274283)the National Key R&D Program of China(No.SQ2022YFC2900065)the Ordos Science&Technology Plan(No.202204&2023XM06)the Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF 2107)。
文摘Effectively strengthening the surface sulfidation is essential for recovering hemimorphite by froth flotation.In this work,inductively coupled plasma optical emission spectrometer(ICP-OES)measurements,Visual MINTEQ calculation,X-ray photoelectron spectroscopy(XPS)analysis,time of flight secondary ion mass spectrometry(ToF-SIMS)analysis,and micro-flotation experiments were explored to systematically investigate the effect of ammonium sulfate((NH_(4))_(2)SO_(4))on the formation of zinc sulfide species on hemimorphite surface and its role in sulfidation flotation.The results showed that(NH_(4))_(2)SO_(4)exhibited a positive influence on hemimorphite sulfidation flotation.It was ascribed to the number of zinc components in the form of Zn^(2+)and[Zn(NH_(3))_(i)]^(2+)(i=1–4)increased in the flotation system after hemimorphite treatment with(NH_(4))_(2)SO_(4),which was beneficial to its interaction with sulfur species in solution,resulting in a dense and stable zinc sulfide layer generated on the hemimorphite surface.[Zn(NH_(3))_(i)]^(2+)participated in the sulfidation reaction of hemimorphite as a transition state.In addition the sulfidation reaction of hemimorphite was accelerated by(NH_(4))_(2)SO_(4).Thus,(NH_(4))_(2)SO_(4)presents a vital role in promoting the sulfidation of hemimorphite.
基金Supported by the National Natural Science Foundation of China(20528706)the China Postdoctoral Science Foundation(20090450385)
文摘Intermolecular geometries and energies of the dimers formed between simple aromatic hydrocarbons （benzene, toluene and naphthalene） and sulfate species （sulfuric acid, bisulfate and sulfate） were studied by density functional theory. The AH：H2SO4 complexes were determined by the OH-π H-bond, with H2SO4 acting as the H-bond donor and AHs as the aeeeptor. However, the AHs：HSO4- and AHs：SO4^2- complexes were established by the H-bond, with AHs serving as acid and HSO4 or SO4^2- as alkali. The atmospheric implications of those complexes were strongly supported by their considerable binding energies.
基金supported by the National Key Research and Development Program of China (No. 2020YFC1808300)National Natural Science Foundation of China (Nos. 42077185, 41772264)the Research Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (No. SKLGP2020Z002)。
文摘Transition metal-based bimetallic oxides can effectively activate peroxymonosulfate(PMS) for the degradation of organic contaminants, which may be attributed to the enhanced electron transfer efficiency between transition metals. Here, we investigated the high-efficiency catalytic activation reaction of PMS on a well-defined bimetallic Fe-Mn nanocomposite(BFMN) catalyst. The surface topography and chemical information of BFMN were simultaneously mapped with nanoscale resolution. Rhodamine B(Rh B, as a model pollutant) was used to evaluate the oxidation activity of PMS activation system. The maximum absorption peak of Rh B obviously blue shifted from 554 nm to 501 nm, and decreased sharply to disappear completely within 60 min. The removal performance is better than most of the reported single transition metal oxide. X-ray photoelectron spectroscopy(XPS) imaging of the BFMN electronic structure after catalytic activation confirmed that the accelerated internal electron transfer is mainly caused by the synergy effect of Mn and Fe sites at the catalysis boundary. The outstanding ability of BFMN for PMS chemical adsorption and activation may attribute to the enhanced covalency and reactivity of Mn-O. These results of this study can advance understandings on the origins of bimetallic oxides activity for PMS activation and developing the efficient metal oxide catalysts in real practice.
文摘Polyferric silicate sulfate （PFSS） with high concentration was prepared using the composite-poly method. The coagulation properties and mechanisms of this new complex were probed using TEM, Fe-Ferron timed complex-colorimetric method, and infrared spectrum method. The results showed that the flocculating effect of polyferric silicate sulfate had an advantage over polyferric sulfate （PFS）, as the optimum coagulation effect could be obtained when the Si/Fe mole ratio was 0.75 in accordance with its macrostructure of PFSS. According to the Fe-Ferron timed complex-colorimetric method, the Si species was mainly Sic, whereas, the Fe species were Fea and Fec in the copolymerization system. The infrared spectra indicated that the structure of these new flocculants was formed by polymers, mainly by olation, which was different from polyferric sulfate, and the vibration of M-OH-M of around 1100 cm^-1, also proved that there existed Fe-OH-Fe and its polymers in some forms.
