The paper presents comparative kinetic characteristics of the decomposition of 2,4-dichlorophenol in a dielectric barrier discharge and a combined plasma-catalytic process. Vermiculite containing 5% zirconium was used...The paper presents comparative kinetic characteristics of the decomposition of 2,4-dichlorophenol in a dielectric barrier discharge and a combined plasma-catalytic process. Vermiculite containing 5% zirconium was used as a catalyst. The destruction processes of 2,4-DCP proceed efficiently, the degree of decomposition increases in the combined plasma-catalytic process by a factor of 1.33 and reaches 80%. The experimental results were processed according to the first-order kinetic law (R<sup>2</sup> > 0.97), according to which the effective constants (0.36 ± 0.04) and (0.51 ± 0.03) s<sup>-1</sup> and the decomposition rates of 2,4-DCP (106 and 123 μmol/l·s) when treating model solutions without a catalyst and with vermiculite + Zr 5%, respectively, and the energy costs are 0.012 and 0.017 molecules/100eV. The main decomposition products present in the solution have been determined to be carboxylic acids, aldehydes, the contribution of which does not exceed 2%, as well as chloride ions, and in the gas phase they are carbon dioxide and molecular chlorine (the share of which does not exceed 1.5% of total chlorine content in the system).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
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).
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
The paper includes the studies on photocatalytic degradation of 2,6-DCP in aqueous phase using titania (PC-105) as a photocatalyst. The degradation experiments were carried out by irradiating the aqueous suspensions o...The paper includes the studies on photocatalytic degradation of 2,6-DCP in aqueous phase using titania (PC-105) as a photocatalyst. The degradation experiments were carried out by irradiating the aqueous suspensions of the model compound in the presence of photocatalysts under UV light. The rate of degradation was estimated from residual concentration spectrophotometrically. Various parameters affecting the degradation process viz. catalyst dose, pH, initial substrate concentration and time were investigated in order to obtain their optimum values. The maximum degradation of 2,6-DCP was achieved with 1.25 g/L catalyst dose at pH-4. The disappearance of 2,6-DCP obeyed pseudo-first order kinetics and the rate constant value was calculated to be 4.78 × 10-4s-1.展开更多
A new fi ber optic sensor based on the oxidation of 2,4-dichlorophenol(DCP) catalyzed by iron(II) phthalocyanine(Fe(II)Pc) was developed for the determination of DCP. The optical oxygen sensing fi lm containin...A new fi ber optic sensor based on the oxidation of 2,4-dichlorophenol(DCP) catalyzed by iron(II) phthalocyanine(Fe(II)Pc) was developed for the determination of DCP. The optical oxygen sensing fi lm containing fl uorescence indicator Ru(bpy)3Cl2 was used to detect the consumption of oxygen in solution. Moreover, a lock-in amplifier was used to determine the lifetime of the sensor head by detecting its phase delay change. The results reveal that the sensor has a linear detection range of 1.0×10^-6- 9.0×10^-5 mol/L and a response time of 5 min. The sensor also has high selectivity, good repeatability and stability. It can be used effectively to determine DCP concentration in real samples.展开更多
The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main produ...The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.展开更多
Laccase possesses a good degradation effect on organic pollutants,but it is too long to achieve the desired effect. In order to improve the treatment effect of laccase on degradation of organic pollutants,2,4-dichloro...Laccase possesses a good degradation effect on organic pollutants,but it is too long to achieve the desired effect. In order to improve the treatment effect of laccase on degradation of organic pollutants,2,4-dichlorophenol( 2, 4-DCP) was selected as a treatment target in the study. This study investigated a newtechnique for catalyzing the degradation of 2,4-DCP, that is,ultrasound-assisted laccase catalysis. The optimal experimental parameters such as p H,ultrasonic power,duty cycle and laccase concentration were determined under optimized experimental conditions. The results showed that the optimum conditions for degradation of 2,4-DCP were that pH = 5. 5,the input power was 105 W,the duty cycle was 50% and the laccase concentration was0. 4 U/m L. The degradation rate of 2,4-DCP reached 77. 5% under the optimum conditions at 4 h. When in ultrasonic environment,the enzymatic activity of laccase could be stimulated and improved.Compared with conventional methods,this technique significantly promoted the degradation rate of 2,4-DCP while reduced action time. Furthermore, no newpollutant was introduced into the degradation process. Therefore,ultrasound-assisted laccase catalysis is an environmentally friendly technique to degrade pollutants.展开更多
In this study, the potential effects of palm kernel oil (PKO), pineapple peels derived-activated carbon (PPAC) and NPK fertilizer (20:10:10) as amendment agents on the natural bioattenuation of 2,6-dichlorophenol (2,6...In this study, the potential effects of palm kernel oil (PKO), pineapple peels derived-activated carbon (PPAC) and NPK fertilizer (20:10:10) as amendment agents on the natural bioattenuation of 2,6-dichlorophenol (2,6-DCP) in tropical agricultural soil were investigated. The effect of PPAC dosage on 2,6-DCP biodegradation was also studied. Column reactors containing soil were spiked with 2,6-dichlorophenol (2,6-DCP) wastewater (300 mg/l) and amended with PKO, NPK fertilizer and PPAC alone or in combinations. The rates of 2,6-DCP biodegradation were studied for a remediation period of 42 days under laboratory conditions. The results showed that there was a positive relationship between the rate of 2,6-DCP biodegradation, bacterial growth rate and presence of NPK fertilizer and PPAC (alone or in combination) in soil column microcosms contaminated with 2,6-DCP. The 2,6-DCP biodegradation data fitted well to the first-order kinetic model. The model revealed that 2,6-DCP contaminated-soil microcosms amended with NPK fertilizer and PPAC (alone or in combination) had higher biodegradation rate constants (k) as well as lower half-life times (t1/2) than soil column microcosms amended with PKO and unamended soil (natural attenuation) remediation system. Thus, the use of combined NPK fertilizer and activated carbon (NPK + PPAC) to enhance 2,6-DCP degradation in the soil could be one of the severally sought bioremediation strategies of remediating natural ecosystem (environment) contaminated with organic chemicals.展开更多
Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were st...Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were studied. All the adsorption isotherms were well fitted to the Freundlich equation. The adsorption capacities of 2,4-dinitrophenol or 2,4-dichlorophenol were dramatically enhanced by HDTMA treatment of red soil. The increase of ionic strength and the addition of divalent heavy metal cation Cu 2+ significantly enhanced the adsorption of 2,4-dinitrophenol or 2,4-dichlorophenol on the HDTMA-modified red soil. Adsorption capacities of HDTMA-modified red soil for 2,4-dinitrophenol and 2,4-dichlorophenol gradually increased with decreasing pH in the aqueous phase.展开更多
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
Sensitized-photocatalytic decomposition of 2,4-dichlorophenol (2,4-DCP) using xan-thene dyes as photosensitizer on TiO2 particles under visible light irradiation was studied. 2,4-DCP can be decomposed efficiently by t...Sensitized-photocatalytic decomposition of 2,4-dichlorophenol (2,4-DCP) using xan-thene dyes as photosensitizer on TiO2 particles under visible light irradiation was studied. 2,4-DCP can be decomposed efficiently by this method and the decomposition efficiency of 2,4-DCP decreases in the following order: eosin Y ≈ rose bengal 】 erythrosine B 】 rhodamine B.展开更多
Herein,with the exploitation of iron and nickel electrodes,the 2,4-dichlorophenol(2,4-DCP)dechlorinating processes at the anode and cathode,respectively,were separately studied via various electrochemical techniques(e...Herein,with the exploitation of iron and nickel electrodes,the 2,4-dichlorophenol(2,4-DCP)dechlorinating processes at the anode and cathode,respectively,were separately studied via various electrochemical techniques(e.g.,Tafel polarization,linear polarization,electrochemical impedance spectroscopy).With this in mind,Ni/Fe nanoparticles were prepared by chemical solution deposition,and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic system.For the iron anode,the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the electrode.The charge transfer resistance(Rct)values of the iron electrode were 703,473,444,and 437Ω·cm2 for the initial 2,4-DCP concentrations of0,20,50,and 80 mg/L,respectively.When the bulk pH of the 2,4-DCP solution varied from 3.0,5.0to 7.0,the corresponding Rct values were 315,376,and 444Ω·cm2,respectively.For the nickel cathode,the reduction current densities on the electrode at-0.75 V(vs.saturated calomel electrode)were 80,106,and 111μA/cm2,for initial 2,4-DCP concentrations of 40,80,and125 mg/L.The dechlorination experiments demonstrated that when the initial pH of the solution was 7.0,5.0,and 3.0,the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%,69%,and 74%,respectively,which was in line with the electrochemical experiments.10 wt.%Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP,and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.展开更多
文摘The paper presents comparative kinetic characteristics of the decomposition of 2,4-dichlorophenol in a dielectric barrier discharge and a combined plasma-catalytic process. Vermiculite containing 5% zirconium was used as a catalyst. The destruction processes of 2,4-DCP proceed efficiently, the degree of decomposition increases in the combined plasma-catalytic process by a factor of 1.33 and reaches 80%. The experimental results were processed according to the first-order kinetic law (R<sup>2</sup> > 0.97), according to which the effective constants (0.36 ± 0.04) and (0.51 ± 0.03) s<sup>-1</sup> and the decomposition rates of 2,4-DCP (106 and 123 μmol/l·s) when treating model solutions without a catalyst and with vermiculite + Zr 5%, respectively, and the energy costs are 0.012 and 0.017 molecules/100eV. The main decomposition products present in the solution have been determined to be carboxylic acids, aldehydes, the contribution of which does not exceed 2%, as well as chloride ions, and in the gas phase they are carbon dioxide and molecular chlorine (the share of which does not exceed 1.5% of total chlorine content in the system).
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.
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.
文摘The paper includes the studies on photocatalytic degradation of 2,6-DCP in aqueous phase using titania (PC-105) as a photocatalyst. The degradation experiments were carried out by irradiating the aqueous suspensions of the model compound in the presence of photocatalysts under UV light. The rate of degradation was estimated from residual concentration spectrophotometrically. Various parameters affecting the degradation process viz. catalyst dose, pH, initial substrate concentration and time were investigated in order to obtain their optimum values. The maximum degradation of 2,6-DCP was achieved with 1.25 g/L catalyst dose at pH-4. The disappearance of 2,6-DCP obeyed pseudo-first order kinetics and the rate constant value was calculated to be 4.78 × 10-4s-1.
基金Funded by the National Natural Science Foundation of China(Nos.61377092 and 51303115)
文摘A new fi ber optic sensor based on the oxidation of 2,4-dichlorophenol(DCP) catalyzed by iron(II) phthalocyanine(Fe(II)Pc) was developed for the determination of DCP. The optical oxygen sensing fi lm containing fl uorescence indicator Ru(bpy)3Cl2 was used to detect the consumption of oxygen in solution. Moreover, a lock-in amplifier was used to determine the lifetime of the sensor head by detecting its phase delay change. The results reveal that the sensor has a linear detection range of 1.0×10^-6- 9.0×10^-5 mol/L and a response time of 5 min. The sensor also has high selectivity, good repeatability and stability. It can be used effectively to determine DCP concentration in real samples.
基金Funded by the National Natural Science Foundation of China(No.61205062)the Hubei Provincial Department of Education Scientific Research Program Guidance Project(No.B2020282)。
文摘The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.
基金National Natural Science Foundation of China(No.41571306)the Project of Excellent Fund in Hubei Province,China(No.2018CFA067)Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,China(No.2017zy003)
文摘Laccase possesses a good degradation effect on organic pollutants,but it is too long to achieve the desired effect. In order to improve the treatment effect of laccase on degradation of organic pollutants,2,4-dichlorophenol( 2, 4-DCP) was selected as a treatment target in the study. This study investigated a newtechnique for catalyzing the degradation of 2,4-DCP, that is,ultrasound-assisted laccase catalysis. The optimal experimental parameters such as p H,ultrasonic power,duty cycle and laccase concentration were determined under optimized experimental conditions. The results showed that the optimum conditions for degradation of 2,4-DCP were that pH = 5. 5,the input power was 105 W,the duty cycle was 50% and the laccase concentration was0. 4 U/m L. The degradation rate of 2,4-DCP reached 77. 5% under the optimum conditions at 4 h. When in ultrasonic environment,the enzymatic activity of laccase could be stimulated and improved.Compared with conventional methods,this technique significantly promoted the degradation rate of 2,4-DCP while reduced action time. Furthermore, no newpollutant was introduced into the degradation process. Therefore,ultrasound-assisted laccase catalysis is an environmentally friendly technique to degrade pollutants.
文摘In this study, the potential effects of palm kernel oil (PKO), pineapple peels derived-activated carbon (PPAC) and NPK fertilizer (20:10:10) as amendment agents on the natural bioattenuation of 2,6-dichlorophenol (2,6-DCP) in tropical agricultural soil were investigated. The effect of PPAC dosage on 2,6-DCP biodegradation was also studied. Column reactors containing soil were spiked with 2,6-dichlorophenol (2,6-DCP) wastewater (300 mg/l) and amended with PKO, NPK fertilizer and PPAC alone or in combinations. The rates of 2,6-DCP biodegradation were studied for a remediation period of 42 days under laboratory conditions. The results showed that there was a positive relationship between the rate of 2,6-DCP biodegradation, bacterial growth rate and presence of NPK fertilizer and PPAC (alone or in combination) in soil column microcosms contaminated with 2,6-DCP. The 2,6-DCP biodegradation data fitted well to the first-order kinetic model. The model revealed that 2,6-DCP contaminated-soil microcosms amended with NPK fertilizer and PPAC (alone or in combination) had higher biodegradation rate constants (k) as well as lower half-life times (t1/2) than soil column microcosms amended with PKO and unamended soil (natural attenuation) remediation system. Thus, the use of combined NPK fertilizer and activated carbon (NPK + PPAC) to enhance 2,6-DCP degradation in the soil could be one of the severally sought bioremediation strategies of remediating natural ecosystem (environment) contaminated with organic chemicals.
文摘Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were studied. All the adsorption isotherms were well fitted to the Freundlich equation. The adsorption capacities of 2,4-dinitrophenol or 2,4-dichlorophenol were dramatically enhanced by HDTMA treatment of red soil. The increase of ionic strength and the addition of divalent heavy metal cation Cu 2+ significantly enhanced the adsorption of 2,4-dinitrophenol or 2,4-dichlorophenol on the HDTMA-modified red soil. Adsorption capacities of HDTMA-modified red soil for 2,4-dinitrophenol and 2,4-dichlorophenol gradually increased with decreasing pH in the aqueous phase.
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.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 20077027, 4001161947 and 20133010) the Foundation of Chinese Academy of Sciences.
文摘Sensitized-photocatalytic decomposition of 2,4-dichlorophenol (2,4-DCP) using xan-thene dyes as photosensitizer on TiO2 particles under visible light irradiation was studied. 2,4-DCP can be decomposed efficiently by this method and the decomposition efficiency of 2,4-DCP decreases in the following order: eosin Y ≈ rose bengal 】 erythrosine B 】 rhodamine B.
基金supported by the National Natural Science Foundation of China (No. 51325102)the Nature Science Foundation of Hubei Province of China (Team Project, No. 2015CFA017)
文摘Herein,with the exploitation of iron and nickel electrodes,the 2,4-dichlorophenol(2,4-DCP)dechlorinating processes at the anode and cathode,respectively,were separately studied via various electrochemical techniques(e.g.,Tafel polarization,linear polarization,electrochemical impedance spectroscopy).With this in mind,Ni/Fe nanoparticles were prepared by chemical solution deposition,and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic system.For the iron anode,the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the electrode.The charge transfer resistance(Rct)values of the iron electrode were 703,473,444,and 437Ω·cm2 for the initial 2,4-DCP concentrations of0,20,50,and 80 mg/L,respectively.When the bulk pH of the 2,4-DCP solution varied from 3.0,5.0to 7.0,the corresponding Rct values were 315,376,and 444Ω·cm2,respectively.For the nickel cathode,the reduction current densities on the electrode at-0.75 V(vs.saturated calomel electrode)were 80,106,and 111μA/cm2,for initial 2,4-DCP concentrations of 40,80,and125 mg/L.The dechlorination experiments demonstrated that when the initial pH of the solution was 7.0,5.0,and 3.0,the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%,69%,and 74%,respectively,which was in line with the electrochemical experiments.10 wt.%Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP,and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.