Plasma-Catalytic Decomposition of 2,4-Dichlorophenol in a Dielectric Barrier Discharge with a Vermiculite ZiO2 Composite

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 (R2 > 0.97), according to which the effective constants (0.36 ± 0.04) and (0.51 ± 0.03) s-1 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).

Statistical optimization of adsorption processes for removal of 2,4-dichlorophenol by activated carbon derived from oil palm empty fruit bunches

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）.

ADSORPTION OF 2,4-DICHLOROPHENOL IN AQUEOUS SOLUTION ONTO ADSORPTION RESIN MODIFIED BY N-ACETYLANILINE

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.

Removal of 2,4-dichlorophenol from wasterwater by vacuum membrane distillation using hydrophobic PPESK hollow hiber membrane

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）.

Enhancing Heterogeneous Catalytic Activity of Iron(II) Phthalocyanine by Ethanol and Its Application in 2,4-dichlorophenol Detection

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.

Photocatalytic Degradation of 2,6-Dichlorophenol in Aqueous Phase Using Titania as a Photocatalyst

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.

A Fiber Optic Sensor for Determination of 2,4-dichlorophenol based on Iron(Ⅱ) Phthalocyanine Catalysis

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.

A Composite Catalytic Oxidation-fluorescence Sensing System for 2,4-dichlorophenol Analysis based on Fe(Ⅲ)PcTs-BuOOH-CdTe QDs

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.

Degradation of 2,4-Dichlorophenol Catalyzed by Ultrasound-Assisted Laccase

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.

Biodegradation of 2,6-Dichlorophenol Wastewater in Soil Column Reactor in the Presence of Pineapple Peels-Derived Activated Carbon, Palm Kernel Oil and Inorganic Fertilizer

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.

Adsorption of 2,4-dinitrophenol and 2,4-dichlorophenol on Cationic Surfactant Modified Red Soil

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.

Kinetics of 2,4-dichlorophenol dechlorination by Pd-Fe bimetallic nanoparticles in the presence of humic acid

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.

“虾壳生物质炭活化过硫酸盐降解2,4-二氯酚”创新实验设计

将科研成果与创新创业实践教学相结合,设计实施创新综合探究实验,以虾壳为原料制备虾壳生物质炭,用于活化过硫酸盐降解2,4-二氯酚。实验结果表明,虾壳生物质炭在酸性和中性条件下可以有效活化过硫酸盐去除2,4-二氯酚,去除率可达96%。通过该实验,学生能够掌握纳米材料的制备、表征等基本实验技能,能够对数据进行处理和分析,树立“以废治废”理念,增强解决实际问题的能力,提高创新意识。

碳纳米管表面等离子体改性活化过一硫酸盐性能研究

将简单高效的等离子体刻蚀方法应用于碳纳米管(CNTs)的表面改性,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和拉曼光谱(Raman)等对改性后的催化剂进行表征分析,结果表明经刻蚀得到的CNTs缺陷程度和氧含量均有较大提升。研究发现改性后的CNTs催化剂可有效提升过一硫酸盐(PMS)活化性能,在降解水中2,4-二氯苯酚(2,4-DCP)的性能研究中反应速率为未改性CNTs的3.2倍,30min内2,4-DCP去除率可达到97%,同时在实际水体和放大实验中也展现出良好的性能。淬灭实验和电子顺磁共振实验结果表明体系中主要的活性物质为单线态氧(^(1)O_(2))。本研究提供了一种简单制备高性能非金属活化PMS催化剂的方法,并在水体中有机污染物的去除中展现出良好的应用前景。

蔗渣纤维素基Zn_(3)In_(2)S_(6)光催化降解2,4-二氯苯酚的研究

文章研究采用蔗渣纤维素和Zn_(3)In_(2)S_(6)为原料,通过化学交联法成功制备了蔗渣纤维素基Zn_(3)In_(2)S_(6)(SBC@ZIS)光催化剂,并利用SBC@ZIS光催化降解2,4-二氯苯酚(2,4-DCP)。运用FT-IR、紫外可见漫反射、SEM-EDS、XPS和XRD对SBC@ZIS物理特性进行表征,并运用高效液相色谱和TOC分析SBC@ZIS降解2,4-DCP的性能。FT-IR和XRD结果证实了SBC与ZIS的结合未显著改变ZIS的结构。通过SEM-EDS表征发现,SBC载体上具有O、C、Zn、In和S元素,在XPS表征中,SBC@ZIS表现出与ZIS同样的衍射峰,两者表征均证明了ZIS很好地负载在SBC上。紫外可见漫反射表明ZIS固定于SBC后,其光吸收范围发生了红移,即从524 nm红移至600 nm,表明SBC@ZIS有利于提高ZIS在可见光下的吸收范围。通过单因素实验可知,在最优条件下,SBC@ZIS对2,4-DCP(50 mg/L)的降解率可达87%,相较于单独ZIS光催化提高了10个百分点。并且总有机碳的去除率达到了71%,相较于ZIS提高了17个百分点。将Zn_(3)In_(2)S_(6)负载于蔗渣纤维素上,有利于提高回收利用性和光催化性能,为2,4-DCP的高效降解提供一种新的思路。

单原子Mn-N-C催化活化过一硫酸盐降解2,4-二氯苯酚

针对2,4-二氯苯酚(2,4-Dichlorophenol,2,4-DCP)对环境污染的危害,急需开发一种清洁高效的处理方式。研究采用模板蚀刻法制备了锚定在氮掺杂碳上的Mn单原子催化剂(Mn-N-C),Mn原子以Mn—N_(x)的形式均匀地稳定在载体上,该结构增强了Mn-N-C材料的极化和电子传递。当Mn-N-C和PMS的投加量分别为50 mg/L和0.8 mmol/L时,在温度为25℃,pH=7.0的条件下,2,4-DCP在60 min内降解率为99.6%,拟一级反应速率常数k_(obs)=0.0786 min^(-1)。通过分析计算,Mn-N-C中Mn—N_(x)和N—(C)3结构活化PMS产生^(1)O_(2)和·O_(2)^(-),而后2,4-DCP主要由^(1)O_(2)通过羟基化、脱氯和开环反应降解,降解产物的毒性大幅降低。试验结果表明:Mn-N-C在活化PMS降解2,4-DCP显现出优异的催化活性;Mn-N-C/PMS体系具有一定抗干扰能力、优异的稳定性和可重复使用性,为实际废水中2,4-DCP的处理提供了一种有效方法。

山竹壳制备吸附-光催化碳材料及其性能

以山竹壳为原料,通过磷酸活化处理、焙烧、浸渍乙酸锌、乙酸银溶液的方法制得复合双金属生物质碳材料AgZn/P/BC,并在可见光照射下研究该复合双金属生物质碳材料对2,4-二氯苯酚(2,4-DCP)的吸附-可见光催化协同降解性能。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、紫外-可见漫反射光谱仪(DRS)、比表面积测试仪(BET)和X射线光电子能谱(XPS)对复合材料进行表征分析,采用高效液相色谱法(HPLC)测定反应物浓度,计算脱除率。分别比较不同金属物质的量比(Ag、Zn)和不同金属乙酸盐溶液浸渍浓度的单一反应条件发现,当金属物质的量比n(Ag)∶n(Zn)为1∶1,金属乙酸盐溶液浓度为0.01 mol/L时,复合材料对2,4-DCP的降解效果最好,黑暗环境中吸附30 min脱除率可达62.33%,光照条件下催化120 min脱除率可达93.52%。动力学研究结果表明,金属乙酸盐溶液浓度为0.01 mol/L的复合双金属生物质碳材料AgZn/P/BC,其降解速率相较于金属乙酸盐溶液浓度为0.03 mol/L的AgZn/P/BC提高了近1.76倍,在pH测试和循环实验中复合材料的催化性能均保持良好,表明AgZn/P/BC具有优异的光催化降解2,4-二氯苯酚性能。

Visible light-sensitized semiconductor photocatalytic degradation of 2,4-dichlorophenol

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.

Understanding the electrode reaction process of dechlorination of 2,4-dichlorophenol over Ni/Fe nanoparticles: Effect of pH and 2,4-dichlorophenol concentration

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.