A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaCIO) and th...A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaCIO) and the combination of ZVI/AC- MDEL/NaCIO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaCIO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaCIO, we found that in the ZVI/AC-MEDL/NaCIO process, ZVI/AC could break the azo bond firstly and then MEDLfNaCIO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.展开更多
The intensification of estrogen non-point source pollution has drawn global attention due to their contribution to ecological environment problems worldwide,and it is critical to develop effective,economic and eco-fri...The intensification of estrogen non-point source pollution has drawn global attention due to their contribution to ecological environment problems worldwide,and it is critical to develop effective,economic and eco-friendly methods for reducing estrogens pollution.To address the agglomeration and oxidation of nano zero-valent iron(nZVI),biochar-nanoscale zero-valent iron composite(nZVI-biochar)could be a feasible choice for estrogens removal.This study summarized biochar and nZVI-biochar preparation,characterization,and unusual applications for estrone(E1),17β-estradiol(E2),and estriol(E3)removal.The properties of biochar and nZVI-biochar in characterization,effects of influencing factors on the removal efficiency,adsorption kinetics,isotherm and thermodynamics were investigated.The experiment results showed that nZVI-biochar exhibited the superior removal performance for estrogens pollutants compared to biochar.Based on the quasi-second-order model,estrogens adsorption kinetics were observed,which supported the mechanism that chemical and physical adsorption existed simultaneously on estrogens removal.The adsorption isotherm of estrogens could be well presented by the Freundlich model and thermodynamics studies explained that nZVI-biochar could spontaneously remove estrogens pollutants and the main mechanisms involvedπ-πinteraction,hydrophobic interaction,hydrogen bonding and degradation through ring rupture.The products analyzed by GC-MS showed that estrogens degradation was primarily attributed to the benzene ring broken,and Fe^(3+)promoted the production of free radicals,which further proved that nZVI-biochar had the excellent adsorption performances.Generally,nZVI-biochar could be employed as a potential material for removing estrogens from wastewater.展开更多
Silica, alumina, and activated carbon supported iron-cobalt catalysts were prepared by incipient wetness impregnation. These catalysts have been characterized by BET, X-ray diffraction (XRD), and temperature-program...Silica, alumina, and activated carbon supported iron-cobalt catalysts were prepared by incipient wetness impregnation. These catalysts have been characterized by BET, X-ray diffraction (XRD), and temperature-programmed reduction (TPR). Activity and selectivity of iron-cobalt supported on different carriers for CO hydrogenation were studied under the conditions of 1.5 MPa, 493 K, 630 h^-1, and H2/CO ratio of 1.6. The results indicate that the activity, C4 olefin/(C4 olefin+C4 paraffin) ratio, and C5 olefin/(C5 olefin+C5 paraffin) decrease in the order of Fe-Co/SiO2, Fe-Co/AC1, Fe-Co/Al2O3 and Fe- Co/AC2. The activity of Fe-Co/SiO2 reached a maximum. The results of TPR show that the Fe-Co/SiO2 catalyst is to some extent different. XRD patterns show that the Fe-Co/SiO2 catalyst differs significantly from the others; it has two diffraction peaks. The active spinel phase is correlated with the supports.展开更多
A catalytic approach using a synthesized iron and manganese oxide-supported granular activated carbon(Fe-Mn GAC) under a dielectric barrier discharge(DBD) plasma was investigated to enhance the degradation of oxytetra...A catalytic approach using a synthesized iron and manganese oxide-supported granular activated carbon(Fe-Mn GAC) under a dielectric barrier discharge(DBD) plasma was investigated to enhance the degradation of oxytetracycline(OTC) in water. The prepared Fe-Mn GAC was characterized by x-ray diffraction and scanning electron microscopy, and the results showed that the bimetallic oxides had been successfully spread on the GAC surface. The experimental results showed that the DBD?+?Fe-Mn GAC exhibited better OTC removal efficiency than the sole DBD and DBD?+?virgin GAC systems. Increasing the fabricated catalyst and discharge voltage was favorable to the antibiotic elimination and energy yield in the hybrid process. The coupling process could be elucidated by the ozone decomposition after Fe-Mn GAC addition, and highly hydroxyl and superoxide radicals both play significant roles in the decontamination. The main intermediate products were identified by HPLC-MS to study the mechanism in the collaborative system.展开更多
An organo-montmorillonite-supported nanoscale zero-valent iron material (M-NZVI) was synthesized to degrade decabromodiphenyl ether (BDE-209). The results showed that nanoscale zero-valent iron had good dispersion...An organo-montmorillonite-supported nanoscale zero-valent iron material (M-NZVI) was synthesized to degrade decabromodiphenyl ether (BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmoriUonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30-90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased.展开更多
Two challenges persist in the applications of nanoscale zero-valent iron(nZVI) for environmental remediation and waste treatment: limited mobility due to rapid aggregation and short lifespan in water due to quick oxid...Two challenges persist in the applications of nanoscale zero-valent iron(nZVI) for environmental remediation and waste treatment: limited mobility due to rapid aggregation and short lifespan in water due to quick oxidation. Herein, we report the nZVI incorporated into mesoporous carbon(MC) to enhance stability in aqueous solution and mobility in porous media. Meanwhile, the reactivity of nZVI is preserved thanks to high temperature treatment and confinement of carbon framework. Small-sized(~16 nm) nZVI nanoparticles are uniformly dispersed in the whole carbon frameworks. Importantly, the nanoparticles are partially trapped across the carbon walls with a portion exposed to the mesopore channels. This unique structure not only is conductive to hold the nZVI tightly to avoid aggregation during mobility but also provides accessible active sites for reactivity. This new type of nanomaterial contains ~10 wt% of iron. The nZVI@MC possesses a high surface area(~ 500 m^2/g) and uniform mesopores(~ 4.2 nm) for efficient pollutant diffusion and reactions. Also, high porosity of nZVI@MC contributes to the stability and mobility of nZVI. Laboratory column experiments further demonstrate that nZVI@MC suspension(~4 g Fe/L) can pass through sand columns much more efficiently than bare nZVI while the high reactivity of nZVI@MC is confirmed from reactions with Ni(II). It exhibits remarkably better performance in nickel(20 mg/L) extraction than mesoporous carbon, with 88.0% and 33.0%uptake in 5 min, respectively.展开更多
基金supported by the Major Projects on Control and Rectification of Water Body Pollution (Water Special Project) (No.2009ZX07010-001,2008ZX07526-001)the National Basic Research Program (973) of China (No.2008CB418201)
文摘A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaCIO) and the combination of ZVI/AC- MDEL/NaCIO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaCIO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaCIO, we found that in the ZVI/AC-MEDL/NaCIO process, ZVI/AC could break the azo bond firstly and then MEDLfNaCIO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.
基金Study on Colloidal Coagulation and Heavy Metal Adsorption Mechanism of Sediment River(No.42007158)Study on the distribution characteristics of birds and the reduction technology of typical pollutants in their habitats in the Yellow River basin(Henan section)(No.23B180008)supported this research.
文摘The intensification of estrogen non-point source pollution has drawn global attention due to their contribution to ecological environment problems worldwide,and it is critical to develop effective,economic and eco-friendly methods for reducing estrogens pollution.To address the agglomeration and oxidation of nano zero-valent iron(nZVI),biochar-nanoscale zero-valent iron composite(nZVI-biochar)could be a feasible choice for estrogens removal.This study summarized biochar and nZVI-biochar preparation,characterization,and unusual applications for estrone(E1),17β-estradiol(E2),and estriol(E3)removal.The properties of biochar and nZVI-biochar in characterization,effects of influencing factors on the removal efficiency,adsorption kinetics,isotherm and thermodynamics were investigated.The experiment results showed that nZVI-biochar exhibited the superior removal performance for estrogens pollutants compared to biochar.Based on the quasi-second-order model,estrogens adsorption kinetics were observed,which supported the mechanism that chemical and physical adsorption existed simultaneously on estrogens removal.The adsorption isotherm of estrogens could be well presented by the Freundlich model and thermodynamics studies explained that nZVI-biochar could spontaneously remove estrogens pollutants and the main mechanisms involvedπ-πinteraction,hydrophobic interaction,hydrogen bonding and degradation through ring rupture.The products analyzed by GC-MS showed that estrogens degradation was primarily attributed to the benzene ring broken,and Fe^(3+)promoted the production of free radicals,which further proved that nZVI-biochar had the excellent adsorption performances.Generally,nZVI-biochar could be employed as a potential material for removing estrogens from wastewater.
文摘Silica, alumina, and activated carbon supported iron-cobalt catalysts were prepared by incipient wetness impregnation. These catalysts have been characterized by BET, X-ray diffraction (XRD), and temperature-programmed reduction (TPR). Activity and selectivity of iron-cobalt supported on different carriers for CO hydrogenation were studied under the conditions of 1.5 MPa, 493 K, 630 h^-1, and H2/CO ratio of 1.6. The results indicate that the activity, C4 olefin/(C4 olefin+C4 paraffin) ratio, and C5 olefin/(C5 olefin+C5 paraffin) decrease in the order of Fe-Co/SiO2, Fe-Co/AC1, Fe-Co/Al2O3 and Fe- Co/AC2. The activity of Fe-Co/SiO2 reached a maximum. The results of TPR show that the Fe-Co/SiO2 catalyst is to some extent different. XRD patterns show that the Fe-Co/SiO2 catalyst differs significantly from the others; it has two diffraction peaks. The active spinel phase is correlated with the supports.
基金supported by National Natural Science Foundation of China (No. 51608468)High School Science and Technology Research Project of Hebei Province (No. QN2018258)+1 种基金China Postdoctoral Science Foundation (Nos. 2015M580216 and 2016M601285)Hebei Province Preferred Postdoctoral Science Foundation (No. B2016003019)
文摘A catalytic approach using a synthesized iron and manganese oxide-supported granular activated carbon(Fe-Mn GAC) under a dielectric barrier discharge(DBD) plasma was investigated to enhance the degradation of oxytetracycline(OTC) in water. The prepared Fe-Mn GAC was characterized by x-ray diffraction and scanning electron microscopy, and the results showed that the bimetallic oxides had been successfully spread on the GAC surface. The experimental results showed that the DBD?+?Fe-Mn GAC exhibited better OTC removal efficiency than the sole DBD and DBD?+?virgin GAC systems. Increasing the fabricated catalyst and discharge voltage was favorable to the antibiotic elimination and energy yield in the hybrid process. The coupling process could be elucidated by the ozone decomposition after Fe-Mn GAC addition, and highly hydroxyl and superoxide radicals both play significant roles in the decontamination. The main intermediate products were identified by HPLC-MS to study the mechanism in the collaborative system.
基金supported by the National Science and Technology Major Projects of Water Pollution Control andManagement of China (No. 2012ZX07206002)
文摘An organo-montmorillonite-supported nanoscale zero-valent iron material (M-NZVI) was synthesized to degrade decabromodiphenyl ether (BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmoriUonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30-90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased.
基金supported by the National Natural Science Foundation of China(Nos.51578398,and 21707104)the National Postdoctoral Program for Innovative Talents(No.BX201700172)the Fundamental Research Funds for the Central Universities(No.0400219376)
文摘Two challenges persist in the applications of nanoscale zero-valent iron(nZVI) for environmental remediation and waste treatment: limited mobility due to rapid aggregation and short lifespan in water due to quick oxidation. Herein, we report the nZVI incorporated into mesoporous carbon(MC) to enhance stability in aqueous solution and mobility in porous media. Meanwhile, the reactivity of nZVI is preserved thanks to high temperature treatment and confinement of carbon framework. Small-sized(~16 nm) nZVI nanoparticles are uniformly dispersed in the whole carbon frameworks. Importantly, the nanoparticles are partially trapped across the carbon walls with a portion exposed to the mesopore channels. This unique structure not only is conductive to hold the nZVI tightly to avoid aggregation during mobility but also provides accessible active sites for reactivity. This new type of nanomaterial contains ~10 wt% of iron. The nZVI@MC possesses a high surface area(~ 500 m^2/g) and uniform mesopores(~ 4.2 nm) for efficient pollutant diffusion and reactions. Also, high porosity of nZVI@MC contributes to the stability and mobility of nZVI. Laboratory column experiments further demonstrate that nZVI@MC suspension(~4 g Fe/L) can pass through sand columns much more efficiently than bare nZVI while the high reactivity of nZVI@MC is confirmed from reactions with Ni(II). It exhibits remarkably better performance in nickel(20 mg/L) extraction than mesoporous carbon, with 88.0% and 33.0%uptake in 5 min, respectively.