The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dic...The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd-Fe bimetallic nanoparticles in the presence of humic acid (HA) to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min?1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.展开更多
The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced b...The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced by thermal activation of activation time with 30 min at 800℃. The adsorption process conditions were determined with the statistical optimization followed by central composite design. A developed polynomial model for operating conditions of adsorption process indicated that the optimum conditions for maximum adsorption of phenolic compound were： agitation rate of 100 r/min, contact time of 8 h, initial adsorbate concentration of 250 mg/L and pH 4. Adsorption isotherms were conducted to evaluate biosorption process. Langmuir isotherm was more favorable （R^2=0.93） for removal of 2,4-dichlorophenol by the activated carbon rather than Freundlich isotherm （R^2=0.88）.展开更多
A hypercrosslinked adsorption resin （ZH-05） modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activat...A hypercrosslinked adsorption resin （ZH-05） modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activated carbon （GAC） and Amberlite XAD-4 were observed. The present study mainly focuses on the static equilibrium adsorption behaviors, desorption profiles and the proof of chemisorption. The results show that the Langmuir equation can give a perfect fitting to experimental data, and high temperature was favorable for adsorption of 2,4-dichlorophenol on ZH-05. A related equation was used to correlate the amount of chemisorption and the suppositionai chemisorption equilibrium concentration of adsorbate in aqueous solution. The adsorption capacities from different ranges of temperature and the static desorption experiment both reveal the same conclusion, i.e., the adsorption of 2,4-dichlorophenol from water on ZH-05 is a coexistent process of physical adsorption and chemical transition as on GAC.展开更多
Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction,...Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction, diffuse‐reflectance spectroscopy, Fourier‐transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption‐desorption. The photocatalytic activities of the catalysts were evaluated in the degradation of 2,4‐dichlorophenol under ultraviolet irradiation. The photocatalytic activity of 50 wt%V2O5‐TiO2 （50V2O5‐TiO2） was higher than those of pure V2O5, TiO2, and P25. Interactions between V2O5 and TiO2 affected the photocatalytic efficiencies of the binary oxide catalysts. Cetyltrimethylammonium bromide （CTAB） and hexadecyltrimethylammonium bromide （HTAB） significantly enhanced the efficiency of the 50V2O5‐TiO2 catalyst. The highest per‐centage of 2,4‐dichlorophenol degradation （100%） and highest reaction rate （2.22 mg/（L·min）） were obtained in 30 min with the （50V2O5‐TiO2）‐CTAB catalyst. It is concluded that the addition of a surfactant to the binary oxide significantly enhanced the photocatalytic activity by modifying the optical and electronic properties of V2O5 and TiO2.展开更多
2,4-Dichlorophenol was removed from wasterwater using a new hydrophobic poly（phthalazinone ether sulfone ketone） （PPESK） hollow fiber membrane by vacuum membrane distillation （VMD）.
Batch experiments were conducted to investigate the adsorption of 2,4-dichlorophenol （2,4-DCP） onto microwave modified activated carbon （AC） at three different temperatures （303 K, 313 K and 323 K）. Adsorption i...Batch experiments were conducted to investigate the adsorption of 2,4-dichlorophenol （2,4-DCP） onto microwave modified activated carbon （AC） at three different temperatures （303 K, 313 K and 323 K）. Adsorption isotherms, kinetics, and thermodynamics of the adsorption process were explored. Equilibrium data were fitted into Langmuir and Freundlich equations, and the result reveals that the Freundlich isotherm model fits better than the Langmuir model. Three simplified kinetic models： pseudo-first-order, pseudo-second-order, and intrapartiele diffusion equations were adopted to examine the mechanism of the adsorption process, and the pseudo-second-order kinetic model proved to be the best in describing the adsorption data. The thermodynamic parameters of the adsorption process were estimated, showing that the adsorption of 2,4-DCP was exothermic and spontaneous, and the adsorption studied in this paper can be assigned to a physisorption mechanism.展开更多
A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could ...A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could be oxidized by dioxygen with the catalysis of Fe（Ⅱ）Pc and then coupled with 4-aminoantipyrine （4-AAP） to generate pink antipyrilquinoneimine dye. Control experiments showed that the addition of ethanol could obviously enhance the catalytic activity of heterogeneous Fe（Ⅱ）Pc catalysts because of the partial dissolution of Fe（II）Pc nanocubes, which was confirmed by the SEM analysis. On the basis of the detection results of DCP in the range from 2×10^-5 to 9×10^-4 mol/L, we obtained a regression equation （A = 0.187 5 ＋ 0.01 209C （R2=-0.995 6）） with the detection limit （3σ） of 3.26×10^-6 mol/L, which could be successfully used in detecting the real samples.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20407015)the Program for the New Century Excel-lent Talents in University (No. NCET-06-0525), China
文摘The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd-Fe bimetallic nanoparticles in the presence of humic acid (HA) to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min?1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.
文摘The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced by thermal activation of activation time with 30 min at 800℃. The adsorption process conditions were determined with the statistical optimization followed by central composite design. A developed polynomial model for operating conditions of adsorption process indicated that the optimum conditions for maximum adsorption of phenolic compound were： agitation rate of 100 r/min, contact time of 8 h, initial adsorbate concentration of 250 mg/L and pH 4. Adsorption isotherms were conducted to evaluate biosorption process. Langmuir isotherm was more favorable （R^2=0.93） for removal of 2,4-dichlorophenol by the activated carbon rather than Freundlich isotherm （R^2=0.88）.
基金This work was supported by the Educational Bureau (No.05KJD610250)the Science & Technology Bureau (No. BS2006032) of Jiangsu Province, China.
文摘A hypercrosslinked adsorption resin （ZH-05） modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activated carbon （GAC） and Amberlite XAD-4 were observed. The present study mainly focuses on the static equilibrium adsorption behaviors, desorption profiles and the proof of chemisorption. The results show that the Langmuir equation can give a perfect fitting to experimental data, and high temperature was favorable for adsorption of 2,4-dichlorophenol on ZH-05. A related equation was used to correlate the amount of chemisorption and the suppositionai chemisorption equilibrium concentration of adsorbate in aqueous solution. The adsorption capacities from different ranges of temperature and the static desorption experiment both reveal the same conclusion, i.e., the adsorption of 2,4-dichlorophenol from water on ZH-05 is a coexistent process of physical adsorption and chemical transition as on GAC.
基金supported by The Scientific and Technological Research Council of Turkey(TUBITAK)within the research project 111M210[2011-2013]~~
文摘Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction, diffuse‐reflectance spectroscopy, Fourier‐transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption‐desorption. The photocatalytic activities of the catalysts were evaluated in the degradation of 2,4‐dichlorophenol under ultraviolet irradiation. The photocatalytic activity of 50 wt%V2O5‐TiO2 （50V2O5‐TiO2） was higher than those of pure V2O5, TiO2, and P25. Interactions between V2O5 and TiO2 affected the photocatalytic efficiencies of the binary oxide catalysts. Cetyltrimethylammonium bromide （CTAB） and hexadecyltrimethylammonium bromide （HTAB） significantly enhanced the efficiency of the 50V2O5‐TiO2 catalyst. The highest per‐centage of 2,4‐dichlorophenol degradation （100%） and highest reaction rate （2.22 mg/（L·min）） were obtained in 30 min with the （50V2O5‐TiO2）‐CTAB catalyst. It is concluded that the addition of a surfactant to the binary oxide significantly enhanced the photocatalytic activity by modifying the optical and electronic properties of V2O5 and TiO2.
文摘2,4-Dichlorophenol was removed from wasterwater using a new hydrophobic poly（phthalazinone ether sulfone ketone） （PPESK） hollow fiber membrane by vacuum membrane distillation （VMD）.
基金Supported by National Natural Science Foundation of China (No20407015)
文摘Batch experiments were conducted to investigate the adsorption of 2,4-dichlorophenol （2,4-DCP） onto microwave modified activated carbon （AC） at three different temperatures （303 K, 313 K and 323 K）. Adsorption isotherms, kinetics, and thermodynamics of the adsorption process were explored. Equilibrium data were fitted into Langmuir and Freundlich equations, and the result reveals that the Freundlich isotherm model fits better than the Langmuir model. Three simplified kinetic models： pseudo-first-order, pseudo-second-order, and intrapartiele diffusion equations were adopted to examine the mechanism of the adsorption process, and the pseudo-second-order kinetic model proved to be the best in describing the adsorption data. The thermodynamic parameters of the adsorption process were estimated, showing that the adsorption of 2,4-DCP was exothermic and spontaneous, and the adsorption studied in this paper can be assigned to a physisorption mechanism.
基金Funded by the National Natural Science Foundation of China(No.61377092)
文摘A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could be oxidized by dioxygen with the catalysis of Fe（Ⅱ）Pc and then coupled with 4-aminoantipyrine （4-AAP） to generate pink antipyrilquinoneimine dye. Control experiments showed that the addition of ethanol could obviously enhance the catalytic activity of heterogeneous Fe（Ⅱ）Pc catalysts because of the partial dissolution of Fe（II）Pc nanocubes, which was confirmed by the SEM analysis. On the basis of the detection results of DCP in the range from 2×10^-5 to 9×10^-4 mol/L, we obtained a regression equation （A = 0.187 5 ＋ 0.01 209C （R2=-0.995 6）） with the detection limit （3σ） of 3.26×10^-6 mol/L, which could be successfully used in detecting the real samples.
