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
In this study,the performance of 3,5-dimethyl-2,4-dichlorophenol（DCMX） degradation by a screened strain was investigated.18 S r DNA and the neighbor-joining method were used for identification of the isolated strain...In this study,the performance of 3,5-dimethyl-2,4-dichlorophenol（DCMX） degradation by a screened strain was investigated.18 S r DNA and the neighbor-joining method were used for identification of the isolated strain.The results of phylogenetic analysis and scanning electron micrographs showed that the most probable identity of the screened strain should be Penicillium sp.Growth characteristics of Penicillium sp.and degradation processes of DCMX were examined.Fourier transform infrared spectroscopy of the inoculated DCMX solution was recorded,which supported the capacity of DCMX degradation by the screened Penicillium sp.Under different salinity conditions,the highest growth rate and removal efficiency for DCMX were obtained at p H 6.0.The removal efficiency decreased from 100%to 66% when the DCMX concentration increased from 5 to 60 mg/L,respectively.Using a Box–Behnken design,the maximum DCMX removal efficiency was determined to be 98.4%.With acclimation to salinity,higher removal efficiency could be achieved.The results demonstrate that the screened Penicillium sp.has the capability for degradation of DCMX.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
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）.
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
Ni was effectively recovered from spent electroless nickel （EN） plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine- formaldehyde-tetraoxalyl-ethylened...Ni was effectively recovered from spent electroless nickel （EN） plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine- formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon （MFT/AG）. PdC12 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite （Ni/AC） in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electro- chemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2.6-dichloronhenol.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
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 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
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
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
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
Sensitized-photocatalytic decomposition of 2,4-dichlorophenol (2,4-DCP) using xanthene dyes as photosensitizer on TiO2 particles under visible light irradiation was studied. 2,4-DCP can be decomposed efficiently by th...Sensitized-photocatalytic decomposition of 2,4-dichlorophenol (2,4-DCP) using xanthene 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
It is essential to develop a cheap, recyclable, and efficient photocatalyst to help degrade pollutants contaminating the environment. Herein, mesoporous molecular sieve titanium phosphate （MMS-TiP） was used as an ef...It is essential to develop a cheap, recyclable, and efficient photocatalyst to help degrade pollutants contaminating the environment. Herein, mesoporous molecular sieve titanium phosphate （MMS-TiP） was used as an efficient nano-photocatalyst to degrade 2,4-dichlorophenol （2,4-DCP） and to oxidize CO. The catalyst was successfully synthesized by a simple and convenient hydrothermal method in the presence of a tri-block copolymer surfactant. Exceptional photoactivity of the optimized MMS-TiP mainly depends on its porous structure, with a large surface area by means of O2 temperature-programmed desorption curves and fluorescence spectra related to the amounts of produced hydroxyl radical. Interestingly, the photocatalytic activity of the prepared MMS-TiP could be greatly improved by coupling with nanocrystalline SnO2. This is likely due to the increase in the lifetime and separation of photogenerated charges by transferring electrons to SnO2 and was observed by steady-state surface photovoltage spectra and time-resolved surface photovoltage responses. The SnOa-coupled MMS-TiP exhibits better photocatalytic performance for 2,4-DCP degradation and better self-settlement than those of the commercial catalyst P25 TiO2. Moreover, it was confirmed by radical-trapping experiments that ·O2^- is the main activated species for the photocatalytic degradation of 2,4-DCP, and is photogenerated by electron transfer from MMS-TiP to SnO2. Furthermore, the main intermediates in the degradation of 2,4-DCP, like parachlorophenol superoxide and 1,2-benzenediol superoxide radicals, were detected, and a possible decomposition pathway related to ·O2^- attack is proposed. These experimental results provide new strategies for developing a recyclable molecular sieve- based nano-photocatalyst with high photocatalytic activity for environmental remediation.展开更多
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 International S&T Cooperation Program of China(No.2015DFG92750)the National Natural Science Foundation of China(Nos.51478172 and 51278464)the Natural Science Foundation of Zhejiang Province of China(No.LY17E080002)
文摘In this study,the performance of 3,5-dimethyl-2,4-dichlorophenol（DCMX） degradation by a screened strain was investigated.18 S r DNA and the neighbor-joining method were used for identification of the isolated strain.The results of phylogenetic analysis and scanning electron micrographs showed that the most probable identity of the screened strain should be Penicillium sp.Growth characteristics of Penicillium sp.and degradation processes of DCMX were examined.Fourier transform infrared spectroscopy of the inoculated DCMX solution was recorded,which supported the capacity of DCMX degradation by the screened Penicillium sp.Under different salinity conditions,the highest growth rate and removal efficiency for DCMX were obtained at p H 6.0.The removal efficiency decreased from 100%to 66% when the DCMX concentration increased from 5 to 60 mg/L,respectively.Using a Box–Behnken design,the maximum DCMX removal efficiency was determined to be 98.4%.With acclimation to salinity,higher removal efficiency could be achieved.The results demonstrate that the screened Penicillium sp.has the capability for degradation of DCMX.
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.
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.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supported by the National Natural Science Foundation of China (Nos. 21076054 and 21174001)the Natural Science Important Foundation of Educational Commission of Anhui Province (Nos. 2010AJZR-85 and 2011AJZR-87)+1 种基金the Study Foundation of New Product and Technology of Anhui Economic and Information Technology Commission (No. 2012AHST0797)the National College Student Innovation Fund (Nos. 201210359034, 2013CXSY327, and 2013CXSY366)
文摘Ni was effectively recovered from spent electroless nickel （EN） plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine- formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon （MFT/AG）. PdC12 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite （Ni/AC） in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electro- chemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2.6-dichloronhenol.
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.
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.
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.
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 xanthene 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We are grateful to financial support from the National Natural Science of China （Nos. U1401245, 21501052, and 91622119）, the Program for Innovative Research Team in Chinese Universities （No. IRT1237）, the Research Project of Chinese Ministry of Education （No. 213011A）, Special Funding for Postdoctoral of Heilongjiang Province （No. LBH-TZ06019） and the Science Foundation for Excellent Youth of Harbin City of China （Nos. 2014RFYXJ002, 2016RQQXJ099 and UNPYSCT-2016173）.
文摘It is essential to develop a cheap, recyclable, and efficient photocatalyst to help degrade pollutants contaminating the environment. Herein, mesoporous molecular sieve titanium phosphate （MMS-TiP） was used as an efficient nano-photocatalyst to degrade 2,4-dichlorophenol （2,4-DCP） and to oxidize CO. The catalyst was successfully synthesized by a simple and convenient hydrothermal method in the presence of a tri-block copolymer surfactant. Exceptional photoactivity of the optimized MMS-TiP mainly depends on its porous structure, with a large surface area by means of O2 temperature-programmed desorption curves and fluorescence spectra related to the amounts of produced hydroxyl radical. Interestingly, the photocatalytic activity of the prepared MMS-TiP could be greatly improved by coupling with nanocrystalline SnO2. This is likely due to the increase in the lifetime and separation of photogenerated charges by transferring electrons to SnO2 and was observed by steady-state surface photovoltage spectra and time-resolved surface photovoltage responses. The SnOa-coupled MMS-TiP exhibits better photocatalytic performance for 2,4-DCP degradation and better self-settlement than those of the commercial catalyst P25 TiO2. Moreover, it was confirmed by radical-trapping experiments that ·O2^- is the main activated species for the photocatalytic degradation of 2,4-DCP, and is photogenerated by electron transfer from MMS-TiP to SnO2. Furthermore, the main intermediates in the degradation of 2,4-DCP, like parachlorophenol superoxide and 1,2-benzenediol superoxide radicals, were detected, and a possible decomposition pathway related to ·O2^- attack is proposed. These experimental results provide new strategies for developing a recyclable molecular sieve- based nano-photocatalyst with high photocatalytic activity for environmental remediation.
