Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the developme...Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the development of low-cost electro-catalysts is still challenging.In this work,a phosphate modified iron(P-Fe)cathode was prepared for electrochemical removal of nitrate in high-salt wastewater.The phosphate modification greatly improved the activity of iron,and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode.Further experiments and density functional theory(DFT)calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO_(3)^(-) removal.The nitrate was firstly electrochemically reduced to ammonium,and then reacted with the anodic generated hypochlorite to N_(2).In this study,a strategy was developed to improve the activity and stability of metal electrode for NO_(3)^(-)removal,which opened up a new field for the efficient reduction of NO3-removal by metal electrode materials.展开更多
In the field of broadband metamaterial absorbers,most research efforts have focused on optimizing the resonant layers and designing multi-layer structures,but relatively little attention has been paid to the dielectri...In the field of broadband metamaterial absorbers,most research efforts have focused on optimizing the resonant layers and designing multi-layer structures,but relatively little attention has been paid to the dielectric layers themselves.This paper proposed a method using carbonyl iron powder to modify the dielectric layer.This method significantly enhances the electromagnetic wave attenuation capability of the dielectric layer with the X-band range for metamaterial absorbers.A broadband absorber with a reflection loss(RL)of less than-10 dB within the frequency range of 4.98-18 GHz and covering the C,X,and Ku band was designed.This work analyzed the surface current distribution and the power loss distribution to elucidate the absorption mechanism of the absorber.It was found that the modified dielectric layer accounted for more than 30%of the total loss in the 2-18 GHz frequency band,and the effective absorption bandwidth(RL≤-10 dB)was almost twice that of the unmodified dielectric layer.This enhancement in absorption bandwidth is attributed to the introduction of a new electromagnetic wave loss mechanism by carbonyl iron powder.Meanwhile,the absorber exhibited good angular stability,maintaining at least 80%absorption(RL≤-7 dB)in the 7.0-18.0 GHz range even when the incident angle was increased to 60°.The experimental results showed that the measured results matched the simulation results well.Furthermore,compared with other methods for broadening the absorption bandwidth,the metamaterial absorber obtained by this method offers several advantages,including wideband absorption,thin profile,and a simple manufacturing process.This approach provides a new and promising direction for the design of broadband absorbers.展开更多
The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization.However,these materials would be inevitably aged by natural forces after entering into the environment,while there ar...The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization.However,these materials would be inevitably aged by natural forces after entering into the environment,while there are seldom studies reported the aging effects of zero-valent iron modified biochar.In this work,the hydrogen peroxide and hydrochloric acid solution were applied to simulate aging conditions of zero-valent iron modified biochar.According to the results,the adsorption capacity of copper(II)contaminants on biochar,zero-valent iron modified biochar-1,and zero-valent iron modified biochar-2 after aging was decreased by 15.36%,22.65%and 23.26%,respectively.The surface interactions were assigned with chemisorption occurred on multi-molecular layers,which were proved by the pseudo-second-order and Langmuir models.After aging,the decreasing of capacity could be mainly attributed to the inhibition of ion-exchange and zero-valent iron oxidation.Moreover,the plant growth and soil leaching experiments also proved the effects of aging treatment,the zero-valent iron modified biochar reduced the inhibition of copper(II)bioavailability and increased the mobility of copper(II)after aging.All these results bridged the gaps between bio-adsorbents customization and their environmental behaviors during practical agro-industrial application.展开更多
In this study,a highly efficient La-Fe_(2)O_(3)/dielectric barrier discharge(DBD)/honeycomb ce-ramic plate synergistic catalytic systemwas successfully constructed by using modified iron oxide(Fe_(2)O_(3))catalyst coa...In this study,a highly efficient La-Fe_(2)O_(3)/dielectric barrier discharge(DBD)/honeycomb ce-ramic plate synergistic catalytic systemwas successfully constructed by using modified iron oxide(Fe_(2)O_(3))catalyst coating assisted DBD plasma,and the prepared catalytic coating was fully characterized by various techniques.The results indicate that the lanthanum(La)is efficiently and uniformly doped in Fe_(2)O_(3),and the modified La-Fe_(2)O_(3)catalyst exhibited a better photocatalytic performance.The overuse of Thiamphenicol(TAP),as a typical chlo-ramphenicol antibiotic,has led to its accumulation in the aquatic environment.Accordingly,TAPwas selected as the target contaminant to evaluate the catalytic activity of the synergis-tic system.The results confirmed that the catalytic ability of the synergistic catalytic system was significantly improved,and the data showed that the degradation rate of the synergis-tic system reached 99.1%under the same conditions compared with 68.2%for the single DBD plasma,which effectively improved low energy efficiency limitations of the single DBD technology.Through quantitative measurements of the concentrations of dissolved ozone(O3)and hydrogen peroxide(H_(2)O_(2))in the system and radical trapping experiments,com-bined with emission spectroscopy,the mechanism of synergistic system degradation of TAP was analyzed.The intermediates in the degradation process were characterized by high-resolution mass spectrometry,and the degradation pathway of TAP was proposed based on the analysis of the intermediates and their combination with theoretical calculations.This study presents a theoretical basis for the improvement of DBD technology and a technical guide for the removal process of antibiotics from industrial wastewater.展开更多
Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising...Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.展开更多
Magnetically responsive composite materials have been used in interesting applications in various areas of bioscience, biotechnology, and environmental technology. In this work, a simple method to determine the amount...Magnetically responsive composite materials have been used in interesting applications in various areas of bioscience, biotechnology, and environmental technology. In this work, a simple method to determine the amount of magnetic iron oxide nano- and microparticles attached to magnetically-modified partic- ulate diamagnetic materials has been developed using a commercially available magnetic permeability meter, The procedure is fast and enables dry particulate magnetically modified materials to be analysed without any modification or pretreatment. We show that the magnetic permeability can be measured for materials containing up to 20% magnetic iron oxide, The magnetic permeability measurements are highly reproducible.展开更多
基金supported by the National Natural Science Foundation of China (No.22176068)the Research and Innovation Initiatives of WHPU (No.2022J03),the Hubei Provincial Natural Science Foundation (No.2023AFB938)the Scientific research project of Education Department of Hubei Province (No.D20221610).
文摘Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the development of low-cost electro-catalysts is still challenging.In this work,a phosphate modified iron(P-Fe)cathode was prepared for electrochemical removal of nitrate in high-salt wastewater.The phosphate modification greatly improved the activity of iron,and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode.Further experiments and density functional theory(DFT)calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO_(3)^(-) removal.The nitrate was firstly electrochemically reduced to ammonium,and then reacted with the anodic generated hypochlorite to N_(2).In this study,a strategy was developed to improve the activity and stability of metal electrode for NO_(3)^(-)removal,which opened up a new field for the efficient reduction of NO3-removal by metal electrode materials.
基金supported by the Key Research and Development Projects of Shaanxi Province,China(No.2020 ZDGY01-01)the Fundamental Research Funds for the Central Universities,China(No.D5000220202).
文摘In the field of broadband metamaterial absorbers,most research efforts have focused on optimizing the resonant layers and designing multi-layer structures,but relatively little attention has been paid to the dielectric layers themselves.This paper proposed a method using carbonyl iron powder to modify the dielectric layer.This method significantly enhances the electromagnetic wave attenuation capability of the dielectric layer with the X-band range for metamaterial absorbers.A broadband absorber with a reflection loss(RL)of less than-10 dB within the frequency range of 4.98-18 GHz and covering the C,X,and Ku band was designed.This work analyzed the surface current distribution and the power loss distribution to elucidate the absorption mechanism of the absorber.It was found that the modified dielectric layer accounted for more than 30%of the total loss in the 2-18 GHz frequency band,and the effective absorption bandwidth(RL≤-10 dB)was almost twice that of the unmodified dielectric layer.This enhancement in absorption bandwidth is attributed to the introduction of a new electromagnetic wave loss mechanism by carbonyl iron powder.Meanwhile,the absorber exhibited good angular stability,maintaining at least 80%absorption(RL≤-7 dB)in the 7.0-18.0 GHz range even when the incident angle was increased to 60°.The experimental results showed that the measured results matched the simulation results well.Furthermore,compared with other methods for broadening the absorption bandwidth,the metamaterial absorber obtained by this method offers several advantages,including wideband absorption,thin profile,and a simple manufacturing process.This approach provides a new and promising direction for the design of broadband absorbers.
基金The authors appreciate the support from the National Natural Science Foundation of China(Grant No.22264025)the Yunnan Province Education Department Scientific Research Foundation Project(Grant No.2022J0136)the Applied Basic Research Foundation of Yunnan Province(Grant Nos.202201AS070020,202201AU070061).
文摘The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization.However,these materials would be inevitably aged by natural forces after entering into the environment,while there are seldom studies reported the aging effects of zero-valent iron modified biochar.In this work,the hydrogen peroxide and hydrochloric acid solution were applied to simulate aging conditions of zero-valent iron modified biochar.According to the results,the adsorption capacity of copper(II)contaminants on biochar,zero-valent iron modified biochar-1,and zero-valent iron modified biochar-2 after aging was decreased by 15.36%,22.65%and 23.26%,respectively.The surface interactions were assigned with chemisorption occurred on multi-molecular layers,which were proved by the pseudo-second-order and Langmuir models.After aging,the decreasing of capacity could be mainly attributed to the inhibition of ion-exchange and zero-valent iron oxidation.Moreover,the plant growth and soil leaching experiments also proved the effects of aging treatment,the zero-valent iron modified biochar reduced the inhibition of copper(II)bioavailability and increased the mobility of copper(II)after aging.All these results bridged the gaps between bio-adsorbents customization and their environmental behaviors during practical agro-industrial application.
基金supported by the National Natural Science Foundation of China(Nos.51978386 and U1906224).
文摘In this study,a highly efficient La-Fe_(2)O_(3)/dielectric barrier discharge(DBD)/honeycomb ce-ramic plate synergistic catalytic systemwas successfully constructed by using modified iron oxide(Fe_(2)O_(3))catalyst coating assisted DBD plasma,and the prepared catalytic coating was fully characterized by various techniques.The results indicate that the lanthanum(La)is efficiently and uniformly doped in Fe_(2)O_(3),and the modified La-Fe_(2)O_(3)catalyst exhibited a better photocatalytic performance.The overuse of Thiamphenicol(TAP),as a typical chlo-ramphenicol antibiotic,has led to its accumulation in the aquatic environment.Accordingly,TAPwas selected as the target contaminant to evaluate the catalytic activity of the synergis-tic system.The results confirmed that the catalytic ability of the synergistic catalytic system was significantly improved,and the data showed that the degradation rate of the synergis-tic system reached 99.1%under the same conditions compared with 68.2%for the single DBD plasma,which effectively improved low energy efficiency limitations of the single DBD technology.Through quantitative measurements of the concentrations of dissolved ozone(O3)and hydrogen peroxide(H_(2)O_(2))in the system and radical trapping experiments,com-bined with emission spectroscopy,the mechanism of synergistic system degradation of TAP was analyzed.The intermediates in the degradation process were characterized by high-resolution mass spectrometry,and the degradation pathway of TAP was proposed based on the analysis of the intermediates and their combination with theoretical calculations.This study presents a theoretical basis for the improvement of DBD technology and a technical guide for the removal process of antibiotics from industrial wastewater.
基金supported by the NSFC-JSPS joint research program(No.51961145202)the National Natural Science Foundation of China(No.52370163,52321005,and 52293443)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS42).
文摘Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.
文摘Magnetically responsive composite materials have been used in interesting applications in various areas of bioscience, biotechnology, and environmental technology. In this work, a simple method to determine the amount of magnetic iron oxide nano- and microparticles attached to magnetically-modified partic- ulate diamagnetic materials has been developed using a commercially available magnetic permeability meter, The procedure is fast and enables dry particulate magnetically modified materials to be analysed without any modification or pretreatment. We show that the magnetic permeability can be measured for materials containing up to 20% magnetic iron oxide, The magnetic permeability measurements are highly reproducible.
