Contact glow discharge electrolysis is a non-Faradaic electrochemical process with an abnormal relationship between the current and voltage. Hydroxyl radicals, hydrogen radicals and hydrogen peroxide can be produced u...Contact glow discharge electrolysis is a non-Faradaic electrochemical process with an abnormal relationship between the current and voltage. Hydroxyl radicals, hydrogen radicals and hydrogen peroxide can be produced under the glow discharge, which are often used to degrade organic contaminants in aqueous solution. In this study, with 4-nitrophenol taken as an example of contaminants and tert-butanol as a scavenger of hydroxyl radicals, the role of energetic species in degrading organic compounds was examined in detail. Moreover, the effects of the applied voltage, solution conductivity and pH on the formation of three energetic species were also observed. The formation rate constants of the three energetic species were calculated based on the experimental data.展开更多
Contact glow discharge electrolysis of some chloroanilines in sodium sulfate was investigated in different initial concentrations. Each of them underwent the dechlorination, deam-ination through oxidative degradation,...Contact glow discharge electrolysis of some chloroanilines in sodium sulfate was investigated in different initial concentrations. Each of them underwent the dechlorination, deam-ination through oxidative degradation, and were eventually decomposed into hydrogen carbonate and carbon dioxide. It was testified that the chlorine atom and amidogen could be transformed into chloride ion and nitrite ion, respectively. Fe2+ has a remarkable catalytic effect on the degradation of them. On the basis of the detailed analysis of the intermediate products and kinetic behaviors, the reaction pathway was proposed, in which the attack of hydroxyl radical on the benzene ring of starting material might be a key step.展开更多
In this paper, we use methyl violet as a model organic substrate in wastewater to study the effect of Fe（Ⅱ） ion on the contact glow discharge electrolysis （CGDE）. The decoloration rate and the COD （Chemical Oxyg...In this paper, we use methyl violet as a model organic substrate in wastewater to study the effect of Fe（Ⅱ） ion on the contact glow discharge electrolysis （CGDE）. The decoloration rate and the COD （Chemical Oxygen Demand） value have been examined. It is found that the presence of Fe（Ⅱ） ion can accelerate obviously the degradation of methyl violet, because it reacts with H2O2 in the CGDE process to yield hydroxyl radical, just acting as a Fenton-like reagent. Moreover, the optimal conditions for decoloring methyl violet were obtained, by means of an orthogonal experiment, to be [Fe^2＋] =1×10^-3 mol/L, applied voltage of 700 V of and pH = 9.0.展开更多
Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that...Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.展开更多
Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode...Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode.During CGDE,PCP degraded smoothly.The amount of total organic carbon decreased significantly,indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons.Furthermore,chlorine atoms in PCP were liberated as chloride ions.As a primary intermediate product,2,3,5,6tetrachloro-1,4-benzoquinone was detected,and oxalate and formate as byproducts were also found.It was revealed that disappearance of PCP obeyed first-order kinetics.The reaction rate was generally unaffected by both O2 and inert gases in the cell,although it decreased by raising initial pH of solution.In addition,a plausible reaction pathway involving hydroxyl radical was proposed.展开更多
Destruction of 4-phenolsulfonic acid （4-PSA） in water was carded out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon （TOC） in water correspondi...Destruction of 4-phenolsulfonic acid （4-PSA） in water was carded out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon （TOC） in water correspondingly decreased, while the sulfonate group of 4- PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH.展开更多
利用接触辉光放电反应器产生等离子体降解直接蓝86(DB)水溶液,考察了DB初始浓度、初始pH和Fe2+对DB降解率的影响.结果表明,当DB初始浓度为30.0 mg/L,溶液pH为3.0时,放电90 min DB降解率可达72.36%;加入10.0 mg/L Fe2+时,放电10 min DB...利用接触辉光放电反应器产生等离子体降解直接蓝86(DB)水溶液,考察了DB初始浓度、初始pH和Fe2+对DB降解率的影响.结果表明,当DB初始浓度为30.0 mg/L,溶液pH为3.0时,放电90 min DB降解率可达72.36%;加入10.0 mg/L Fe2+时,放电10 min DB降解率可达69.20%.DB降解过程中,随反应时间的延长,溶液pH值逐渐降低,溶液电导率逐渐上升.降解90 min后COD去除率为41.76%,加入10.0 mg/L Fe2+后10 min COD去除率达38.50%,表明Fe2+对DB降解有明显的催化作用.展开更多
基金the Key Project of Science and Technology of Education Ministry(00250)the Natural Science Foundation of Gansu Province(3ZS041-A25-028)+1 种基金the Invention Project of Science & Technology of NWNU(KJCXGC-01)Gansu Key Lab of Polymer Materials,China.
文摘Contact glow discharge electrolysis is a non-Faradaic electrochemical process with an abnormal relationship between the current and voltage. Hydroxyl radicals, hydrogen radicals and hydrogen peroxide can be produced under the glow discharge, which are often used to degrade organic contaminants in aqueous solution. In this study, with 4-nitrophenol taken as an example of contaminants and tert-butanol as a scavenger of hydroxyl radicals, the role of energetic species in degrading organic compounds was examined in detail. Moreover, the effects of the applied voltage, solution conductivity and pH on the formation of three energetic species were also observed. The formation rate constants of the three energetic species were calculated based on the experimental data.
基金The project supported by a grant from Key Project of Science and Technology of Education Ministry, China (No. 00250) the program of KJCXGC-01, NWNU, China
文摘Contact glow discharge electrolysis of some chloroanilines in sodium sulfate was investigated in different initial concentrations. Each of them underwent the dechlorination, deam-ination through oxidative degradation, and were eventually decomposed into hydrogen carbonate and carbon dioxide. It was testified that the chlorine atom and amidogen could be transformed into chloride ion and nitrite ion, respectively. Fe2+ has a remarkable catalytic effect on the degradation of them. On the basis of the detailed analysis of the intermediate products and kinetic behaviors, the reaction pathway was proposed, in which the attack of hydroxyl radical on the benzene ring of starting material might be a key step.
基金supported in part by the Project of Key Science and Technology of Education Ministry （00250）the Natural Science Foundation of Gansu Province （3ZS041-A25- 028）the Invention Project of Science ＆： Technology of NWNU （KJCXGC-01）, and Gansu Key Lab of Polymer Materials, China
文摘In this paper, we use methyl violet as a model organic substrate in wastewater to study the effect of Fe（Ⅱ） ion on the contact glow discharge electrolysis （CGDE）. The decoloration rate and the COD （Chemical Oxygen Demand） value have been examined. It is found that the presence of Fe（Ⅱ） ion can accelerate obviously the degradation of methyl violet, because it reacts with H2O2 in the CGDE process to yield hydroxyl radical, just acting as a Fenton-like reagent. Moreover, the optimal conditions for decoloring methyl violet were obtained, by means of an orthogonal experiment, to be [Fe^2＋] =1×10^-3 mol/L, applied voltage of 700 V of and pH = 9.0.
基金The project supported by the Key Project of Science and Technology from the Ministry of Education China (No. 00250) the project of KJCXGC-01 of Northwest Normal University, China
文摘Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.
基金support from "Open Research Center" Projects for Private Universities:matching fund subsidy from Ministry of Education,Culture,Sports,Science and Technology,2007-2011
文摘Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode.During CGDE,PCP degraded smoothly.The amount of total organic carbon decreased significantly,indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons.Furthermore,chlorine atoms in PCP were liberated as chloride ions.As a primary intermediate product,2,3,5,6tetrachloro-1,4-benzoquinone was detected,and oxalate and formate as byproducts were also found.It was revealed that disappearance of PCP obeyed first-order kinetics.The reaction rate was generally unaffected by both O2 and inert gases in the cell,although it decreased by raising initial pH of solution.In addition,a plausible reaction pathway involving hydroxyl radical was proposed.
基金supported by the 'Youth Science Foundation of University of Science and Technology Liaoning', 2012-2014
文摘Destruction of 4-phenolsulfonic acid （4-PSA） in water was carded out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon （TOC） in water correspondingly decreased, while the sulfonate group of 4- PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH.
文摘利用接触辉光放电反应器产生等离子体降解直接蓝86(DB)水溶液,考察了DB初始浓度、初始pH和Fe2+对DB降解率的影响.结果表明,当DB初始浓度为30.0 mg/L,溶液pH为3.0时,放电90 min DB降解率可达72.36%;加入10.0 mg/L Fe2+时,放电10 min DB降解率可达69.20%.DB降解过程中,随反应时间的延长,溶液pH值逐渐降低,溶液电导率逐渐上升.降解90 min后COD去除率为41.76%,加入10.0 mg/L Fe2+后10 min COD去除率达38.50%,表明Fe2+对DB降解有明显的催化作用.
