辉光放电等离子体处理活性艳红X-3B染料废水实验研究

辉光放电电解是一种新型的电化学过程,其中等离子体由电极和电解质液面之间的直流辉光放电来维持。在惰性电解质水溶液中进行辉光放电电解,可以产生大量的·OH、·H、e-aq、HO2·等活性粒子,进而降解各种有机物。文章采用辉光放电等离子体降解活性艳红X-3B,详细考察了多种因素对活性艳红降解效果的影响。实验发现,提高溶液酸度和增加电压均可提高活性艳红的脱色效果,加入一定量Fe2+能明显提高活性艳红的脱色效率。优化后的最佳条件为:电压为570 V,p H为3.04,活性艳红初始浓度为60 mg/L,Fe2+的用量为2 mmol/L,20 min内活性艳红的脱色率达到98.8%。     

高浓度活性艳红K-2BP溶液光催化氧化脱色研究

以 1 2 5 W高压汞灯为光源 ,Ti O2 为催化剂 ,考察了催化剂用量、H2 O2 的投加、起始 p H等因素对高浓度活性艳红 K- 2 BP( 1 g/L)水溶液的光催化氧化脱色的影响。结果表明 ,仅加入 Ti O2 短时间内不能有高的脱色率 ,但只需加入少量 H2 O2 就可以大幅度提高脱色率。 p H对高浓度活性艳红 K- 2 BP水溶液脱色率的影响较大 ,起始 p H越小 ,脱色率越高。     

添加NaCl对亚甲基蓝电化学脱色过程的影响研究

以Pt片做工作电极和辅助电极,NaCl为活性电解质构成实验用50mL电化学反应器,研究了水相中亚甲基蓝的电化学脱色过程。通过改变pH值、电流密度、染料浓度和NaCl浓度等调控因子,考察了不同条件下的降解过程。实验结果表明,添加NaCl可提高电解效率,在NaCl浓度为0．2mol／L、电流密度为10mA／cm^2和室温条件下,5mg／L的亚甲基蓝经电化学降解1h,脱色率可达91．8％。pH对亚甲基蓝的脱色率影响较大,初始pH越小,脱色率越高。     

Fe-TiO_2对活性艳红K-2BP的光催化降解研究

采用溶胶-凝胶-浸渍法对二氧化钛进行掺铁改性,并以活性艳红K-2BP为降解模型反应物,研究了Fe-TiO2的光催化活性。结果表明:掺铁能够提高二氧化钛的光催化活性,当掺铁质量百分比为0.1%,煅烧温度为500℃,催化活性最好,当催化剂的投加量为3 g/L,通气量为600 mL/min,pH值为3时,对活性艳红K-2BP溶液紫外光照30 min的降解率可达到98.4%。     

直接电解法降解活性艳红X-3B的研究

自制了Ti/Sb_2O_5+SnO_2/α-PbO_2/Ce+β+PbO_2和氧电极,并用XRD,SEM对电极进行表征和性能测试.利用该电极体系降解活性艳红X-3B,研究了电流密度、Fe~(2+)投加量、初始pH、曝气量等因素对活性艳红X-3B降解效果的影响.结果表明,该电极体系实现了阳极和阴极的"协同催化氧化",对活性艳红X-3B具有很好的降解效果.电解50min时,脱色率接近100%,该反应过程遵循1级动力学模式.     

AgCl光催化降解活性艳红K-2BP染料的研究

以300W高压汞灯为光源,研究了AgCl对染料废水进行光催化氧化的可行性,以及溶液初始pH值、催化剂的投加量和光照时间等因素对光降解反应的影响.结果表明,在实验条件下,AgCl对活性艳红K-2BP染料有明显的降解效果.AgCl在光照条件下使有机物分解,酸性条件比碱性条件有利于活性艳红的降解,当催化剂用量为0.5 mmol/L时,10 min光照,染料废水降解率达69.9%.     

复合铝絮凝剂的制备及其脱色性能研究

以三氯化铝和有机高分子PGA为原料,制备了复合絮凝剂CPAC,并探讨了该种絮凝剂对模拟染料废水的脱色作用.研究表明,在同等铝盐投量的情况下,相对于PAC而言,CPAC脱色效率明显提高,且脱色率随PGA与铝盐的质量比(O/A)增高而上升.以活性艳红K-2BP染料为例,铝盐投加质量浓度6.8 mg/L时,PAC脱色率75.5%,CPAC(O/A=0.05)脱色率为81%,CPAC(O/A=0.1)脱色率为86%.3种染料中,CPAC对分散黄G的脱色效果最好,铝盐投加质量浓度为3.3 mg/L时脱色率达98%.     

废碳钢电极处理活性艳红染料的实验研究

本文研究了铁电极处理活性艳红染料X-3B.选取不同电流、电导率、pH、电解质和浊度作为影响脱色率的因素,初步探讨了铁电极脱色的机理和反应动力学.结果表明:电流为1A,KCI浓度为2g/L,电解时间为12min时,脱色率高达99.5%,反应机理主要为协同沉淀和吸附作用.     

电化学方法降解活性艳红X-3B

该文以负载Cu2+活性炭-Co-PbO2/不锈钢-不锈钢三维电极体系处理活性艳红X-3B模拟印染废水。试验结果表明:当电解时间为30 min,电流密度为25 mA/cm2,极板间距为6 cm,氯化钠支持电解质投加量为0.2 mol/L,投加Cu2+负载量为0.5 mol/L,活性炭用量为25 mg时,处理浓度为50 mg/L的活性艳红溶液30 min时,降解率达到95.8%。该方法适用于较宽的pH范围。通过降解前后紫外可见光谱分析可以看出,随着反应的进行,活性艳红分子被彻底降解为小分子物质。     

钇掺杂TiO2/膨润土复合光催化剂降解染料X-3B的研究

以膨润土为载体,钛酸四丁酯和氯化钇为原料,采用溶胶-凝胶法制备钇掺杂TiO2/膨润土纳米复合光催化剂,在太阳光照射下,通过染料活性艳红X-3B的降解反应,考察其光催化活性.实验结果表明：随着光照时间的延长,染料活性艳红X-3B的特征峰540 nm强度逐渐减弱,2 h后可彻底消失,脱色率达96.86%;染料活性艳红X-3B的降解速率随着外加氧化剂H2O2的增多而增大,但过量的H2O2也会抑制复合光催化剂的活性;在强酸和强碱条件下,染料活性艳红X-3B的降解率较高.     

Electro-catalytic degradation of methylene blue wastewater assisted by Fe2O3-modified kaolin

The electrochemical oxidation of methylene blue (MB) wastewater assisted by Fe₂O₃-modified kaolin in a 200 mL electrolytic batch reactor with graphite plate as electrodes was investigated. The catalyst was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of pH, current density and introduction of NaCl on the efficiency of the electrochemical degradation process were also studied. It was found that Fe₂O₃-modified kaolin has higher catalytic activity in the electrochemical degradation of MB wastewater. 96.47% chemical oxygen demand (COD) removal was obtained in 40 min of electrochemical treatment of MB wastewater at pH 3, current density was equal to 69.23 mA cm⁻².     

钼改性高岭土在造纸废水处理中的应用

以钼改性高岭土为催化剂,采用电化学降解的方法处理造纸废水,研究了造纸水初始pH、矿化度、催化剂负载不同离子对废水处理效果的影响。研究表明,改性高岭土负载铁离子作催化剂,pH为4时COD去除率最好,达到90%以上。     

Electrochemical Degradation of Thiocarbamates in NaCl Solutions

Electrochemical degradation of thiocarbamate active ingredients was investigated in aqueous NaCl solutions. Degradation was studied with spectrophotometric methods that allowed specific light absorptions of thiocarbamates (212–220 nm), HClO (236–238 nm) and Cl₂ (225–233 nm) to be periodically or continuously measured. Measurements were also done through chromatographic analysis. The results indicate that under the reaction conditions applied, the electrochemical degradation of thiocarbamates in NaCl solutions takes place not only on the electrode but mainly in the solution phase through ‘indirect’ electrolysis involving the intermediates of NaCl electrolysis (Cl₂, HClO, ClO⁻). This degradation process can be controlled efficiently with the help of electrochemical reaction parameters.     

钒改性催化剂的制备及其在造纸废水处理中的应用

制备了负载型的钒改性高岭土催化剂,采用红外光谱（FTIR）、X射线衍射分析（XRD）手段对制备的改性高岭土进行了表征,并以钒改性高岭土为催化剂,采用电化学降解的方法研究了造纸水初始pH、造纸水中盐含量、催化剂负载不同离子对造纸废水处理效果的影响。研究表明改性高岭土负载铁离子作催化剂、pH=4时,COD去除率最好,达到约76%。     

Electro-oxidation of diclofenac at boron doped diamond: Kinetics and mechanism

Diclofenac is a common anti-inflammatory drug. Its electrochemical degradation at boron doped diamond electrode was investigated in aqueous solution. The degradation kinetics and the intermediate products were studied. Results showed that electro-oxidation was effective in inducing the degradation of diclofenac with 30 mg/L initial concentration, ensuring a mineralization degree of 72% after a 4 h treatment with the applied bias potential of 4.0 V. The effects of applied bias potential and addition of NaCl on diclofenac degradation were investigated. Different degradation mechanisms of diclofenac were involved at various applied bias potentials. With the addition of NaCl, some chlorination intermediates including dichlorodiclofenac were identified, which lead to the total organic carbon increase compared with the electrolysis process without NaCl addition at the reaction initial period. The main intermediates including 2,6-dichlorobenzenamine, 2,5-dihydroxybenzyl alcohol, and benzoic acid are identified at the time of 2 h. 1-(2,6-Dichlorocyclohexa-2,4-dienyl)indolin-2-one were also identified. These intermediates disappeared gradually with the extension of reaction time. Small molecular acids were identified finally. Based on these results, a degradation pathway of diclofenac was proposed.     

电化学氧化法处理海洋油田废水

在开采海洋油田时产生的废水，由于其含有苯系衍生物和多环芳烃化合物及氯离子，用生化降解法难以使其COD值达到我国有关法规规定的一级排放标准。用电化学氧化法处理某海洋油田废水，能使其COD值降至一级排放标准以下。用钛基钌铱锰锡钛多元氧化物涂层电极作阳极，钛作阴极，测定上述污水的电化学氧化指数（Electrochemical Oxidation Index）为0．228，电化学耗氧量（Electrochemical Oxygen Demand）为1．794g/g（以有机物计），其电化学氧化度75．3％，在电化学副反应产生的NaClO的协同作用下，电化学降解后产生的部分有机物可以进一步的进行化学降解，从而达到几乎完全消除废水中COD值的目的。     

RuO2/Ti阳极电化学氧化吸收氨废气

采用溶液吸收结合电化学氧化法处理氨废气。电化学反应器采用尺寸为φ35mm×350mm的管式玻璃反应器,内壁贴附不锈钢网作为阴极,反应器中心轴向设置有φ10mm×350mm的钌钛电极(RuO₂/Ti)棒作为阳极。电极浸没在吸收液中,含氨气体从反应器底部经气体分布器导入反应器。实验结果表明,与溶液吸收相比,溶液吸收结合电化学氧化可以更长时间保持较高的氨气去除率。由于RuO₂/Ti电极产生的有效氯的间接氧化作用,氨气在NaCl溶液比在Na₂SO₄溶液中的去除率更高。以NaCl为电解液时,酸性条件下更有利于氨气的吸收和降解,并且氨气的去除率随着电流密度的增加而增加。产物分析发现氨气在NaCl和Na₂SO₄溶液中被电化学氧化后,主要产物为氮气,也有少量氨转化为硝酸根离子。     

Influence of chloride ion concentration on the electrochemical corrosion behaviour of plasma electrolytic oxidation coated AM50 magnesium alloy

The electrochemical degradation of a silicate- and a phosphate-based plasma electrolytic oxidation (PEO) coated AM50 magnesium alloy obtained using a pulsed DC power supply was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in NaCl solutions of different chloride ion concentrations viz., 0.01 M, 0.1 M, 0.5 M and 1 M. The surface of the PEO coated specimens after 50 h of immersion/EIS testing was examined by optical microscopy and scanning electron microscopy. The results showed that the corrosion deterioration of PEO coated magnesium alloy in NaCl solutions was significantly influenced by chloride ion concentration. The silicate-based coating was found to offer a superior corrosion resistance to the magnesium substrate than the phosphate-based coatings in lower chloride ion concentration NaCl solutions (0.01 M and 0.1 M NaCl). On the other hand both these PEO coatings were found to be highly susceptible to localized damage, and could not provide an effective corrosion protection to Mg alloy substrate in solutions containing higher chloride concentrations (0.5 M and 1 M). The extent of localized damage was observed to be more with increase in chloride concentration in both the cases.     

Electrochemical degradation of azo dye C.I. Reactive Red 195 by anodic oxidation on Ti/SnO2-Sb/PbO2 electrodes

This study investigated the electrochemical degradation of C.I. Reactive Red 195 (RR195) in aqueous solution on a Ti/SnO₂-Sb/PbO₂ electrode. The influence of operating variables on the mineralization efficiency was studied as a function of the current density, the initial pH, the initial concentration of the dye and the addition of NaCl. The efficiency of RR195 mineralization decreased with increased initial concentration, from 100 mg L⁻¹ to 400 mg L⁻¹. The current density had both a positive and a negative effect on degradation rates, and no significant effect of initial pH on RR195 mineralization was observed. Measurement of absorbance was used to discriminate the effect of NaCl in the electro-oxidation process. We found that the decolouring efficiency increased whereas the mineralization efficiency decreased with the increasing concentration of NaCl. The intermediates formed during the degradation were detected by gas chromatography-mass spectrometry, and the major aromatic intermediates identified were 1-(3,6,8-trihydroxy-1-naphthyl)urea, nitrobenzene, benzo-1,4-quinone, (3,6,8-trihydroxy-1-naphthyl)carbamic acid and phthalic acid. Quantitative measurement of organic and inorganic ions was done by ion chromatography. On the basis of the reaction products identified, a possible degradation pathway for the anodic oxidation of RR195 in aqueous solution is proposed.