三维电极电化学反应器对有机废水的降解研究

本文提出一种基于三维电极电化学反应器处理有机废水的新技术 ,结果表明 :该反应器能有效地去除苯胺 ,但其去除率受外加电压、溶液中Fe2 +的浓度、pH值及处理时间 (t)的影响较大 .该项技术处理有机废水效果明显 ,主要是基于电致过氧化氢 ,在Fe2 +存在情况下迅速生成对有机物有很强氧化作用的羟基自由基 .通过ESR法测出了在该电化学反应器处理废水过程中产生的羟基自由基     

电催化氧化技术处理苯酚废水研究

电化学氧化法可有效处理挥发酚类废水,而阳极材料性能直接制约其电氧化效率.本文分别针对不锈钢、柔性石墨和SnO2 /Ti复合材料测定了其析氧过电位,并以不锈钢、柔性石墨为阳极材料,在 5~6V直流电压下,对合成苯酚废水进行了电化学氧化处理.结果表明:析氧过电位次序为SnO2 /Ti>柔性石墨 >不锈钢,处理后水的COD值接近或小于 100mg·L-1,且出水的苯酚浓度小于 0. 5mg·L-1.     

工业含铬废水的络合萃取处理工艺研究

采用络合萃取法处理工业含铬废水,考察了起始pH、流速和接触时间等对络合萃取处理效果的影响,探讨了铬盐生产废水和电镀废水的处理工艺。结果表明;在废水起始pH为1.0-2.0时,络合萃取法能方便、快速、有效地去除废水中的六价铬。络合萃取．碱沉淀法适用于六价铬含量远大于三价铬含量的电镀废水的处理,氧化．络合萃取法可用于三价铬含量较高的电镀废水的处理。采用两级处理能使高浓度铬盐生产废水的出水达到国家排放标准。     

高浓度甲醛废水预处理工艺研究

采用“尿素缩合-粉煤灰吸附-Fenton氧化”复合工艺来处理高浓度甲醛废水,对影响甲醛去除率的因素进行了试验探讨,并确定了工艺优化条件．用该工艺处理高浓度甲醛废水,甲醛的总去除率可达到99％以上,能满足最终生化处理的要求．     

镧掺杂对Ti/Sb-SnO2阳极电催化性能影响的研究

元素掺杂是一种有效改善电极性能的手段。为了提高钛基锡系形稳阳极的催化活性,La被作为一种改性剂掺杂在Ti/Sb-SnO2电极的涂层中。掺杂改性后电极涂层的形貌通过SEM及XRD进行了检测;并通过EDS检测了涂层中各元素的组成比例;利用电化学阳极极化曲线(LSV)测试了电极的电化学性能。利用掺杂改性后的电极和未改性电极电解处理模拟对硝基苯酚(p-NP)废水,在相同条件下,掺杂La改性后电极处理废水的降解率为92.8%,远高于未改性电极处理废水的降解率(72%)。实验表明,稀土La改性后的Ti/Sb-SnO2电极在处理p-NP废水的优越性相当明显。     

苯酚在含氯体系中的电化学氧化

以Ru-Ir/Ti三元电极作阳极电解处理苯酚废水,研究废水中Cl-初始浓度对处理效果的影响.结果表明,在一定的电解时间内,苯酚的电化学氧化符合一级动力学方程;废水中Cl-的初始浓度越大,苯酚完全被氧化所需的时间也越短,即其表观速率常数越大.苯酚在Cl-体系中降解的中间产物主要有4-氯苯酚,1-氯苯酚,2,4-二氯苯酚,2,6二氯苯酚,2,4,6-三氯苯酚及各种短链脂肪酸和氯代醇等;最终产物是CO2、CHCl2和CHCl3.电解中间体的生成和降解速率随废水中Cl-初始浓度的增加而增大.据此,导出苯酚在含Cl-体系中电化学氧化的反应途径.     

印染废水的电化学深度处理及回用研究

针对印染废水水质特性,在PbO₂/Ti阳极、不锈钢板阴极的电解反应器中研究了电化学氧化对印染废水生化出水的处理效果. 试验结果表明,电氧化工艺可以实现化学需氧量（Chemical Oxygen Demand,COD）、氨氮和色度的同步去除. 在电流密度10 mA·cm^-2时电解60 min,废水中COD、氨氮、色度、氯离子浓度以及pH值等指标均可达到GB/T 19923-2005《城市污水再生利用工业用水水质》中工艺与产品用水标准,电流效率达45.6%,吨水能耗4.1 kW·h.     

洁净环境中的电化学

本文综述了电化学技术在洁净环境方面所取得的进展。电化学技术因其独特的功能, 可以有效地应用于处理废气、废水和废渣, 转化与利用二氧化碳, 饮用水消毒, 回收资源, 提供洁净、高效的能源, 连续监测环境的状态。电化学工业的工艺改进大大地减小了对环境的危害。     

树脂吸附法处理甲基—1605农药生产过程中产生的对硝基酚钠废水

本文研究了CHA-103吸附树脂处理甲基-1605农药生产过程中产生的对硝基酚钠废水的最佳工艺条件,结果表明,废水中对硝基酚钠浓度为255mg/l时,处理后废水中对硝基酚钠含量可降低到3mg/l以下,去除率在99％以上,可处理废水达160BV,处理后废水近于无色,树脂脱附再生过程中可同时回收对硝基酚钠。     

电化学预处理微纤维电极用于毛细管电泳安培检测局部麻醉药

本文研究了电化学预处理碳纤维的各种条件，如处理电压、处理时间、处理后稳定时间、溶液条件等对局部麻醉药普鲁卡因、利多卡因电化学行为的影响。找出的电化学预处理最佳条件是在２．０Ｖ进行１．５ｍｉｎ阳极化处理并在缓冲液中保持１０ｍｉｎ。     

A solid composite electrode for the determination of the electrochemical oxygen demand of aqueous samples

A composite electrode containing graphite, paraffin, AgO and CuO is described for the determination of the electrochemical oxygen demand (EOD) of waste waters. The oxidation of dissolved organic compounds at the electrode is based on a heterogeneous chemical reaction of AgO/CuO with the organic constituents of the waste water. This chemical reaction can be followed by a solid state electrochemical oxidation of the formed Ag₂O/Cu₂O. The method has been tested with various organic compounds and applied to real samples of sewage water. The EOD values correlate well to BOD and COD values.     

Abatement of waste-water biorefractory organics via electro-oxidative treatment

The electrochemical oxidation of coumaric acid, a biorefractory compound present in several industrial waste waters, has been investigated by use of Pt-Ti anodes and at electrolyte concentration (0.02 N NaCl or Na2SO4) low enough to allow direct dischargeability of the waste water into superficial water basins according to the Italian law (DL 152/11-5-99). Particularly, the role of the electrolyte over the conversion rate has been assessed. The obtained results show that the oxidation process should take place both at the electrode surface and in the bulk of the solution, via electrochemically-generated oxidising species (H2O2, persulfates, Cl2, NaClO). The faster coumaric acid abatement rates were found with chloride based electrolytes, which, however, lead to the formation of non-biodegradable small-molecular-weight chlorinated hydrocarbons.     

Electrochemical de-chlorination/transformation of metal chloride for the preparation of NZP structure product

A new two-step process was investigated to treat LiCl molten salt waste containing volatile radionuclides generated from an electro-metallurgical processing (pyro-processing) of spent oxide fuels. First, the chemical form of the soluble LiCl waste was transformed into a chloride-free and less soluble hydroxide compound by an electrochemical method, where an electrolytic de-chlorination was performed without adding any chemical salt. Then, a gelation process of the chemical form-changed Li compound, named gel-route stabilization/solidification (GRSS) system aimed to reduce the volatility of the radionuclides greatly, was introduced to stabilize/solidify the hydroxide salt wastes. The application of the electrochemical dechlorination/transformation process and the subsequent gel-route stabilization process to treat the soluble LiCl salt wastes was found to be effective.     

Electrochemical oxidation of tetracycline on a boron doped diamond electrode within the stability potentials of water

Electrochemical oxidation of tetracycline on a boron doped diamond electrode within the stability potentials of water was studied in order to develop an approach for the purification of waste water containing medicinal agents. Cyclic voltammetry, HPLC, and high resolution mass spectrometry were used to establish that in the electrochemical oxidation process, tetracycline adds one oxygen atom to further form organic compounds with molecular weights higher than that of tetracycline. It was found that tetracycline in this region of potentials can be almost completely deactivated without its mineralization.     

巯基取代噻二唑自组装铂电极测定对苯二酚

用自己合成的巯基取代噻二唑试剂对铂电极进行了首次自组装,用电化学方法研究了该电极的电化学性质.研究了对苯二酚在该电极上的电化学行为.实验结果表明,在0.1mol/LKCl溶液中,对苯二酚表现出一种准可逆行为,峰电流对称且峰电位差为80mV,峰电位较之裸铂电极上有较大的降低,峰电流较裸电极大大提高.利用该电极DPV法进行了对苯二酚的电化学测定,峰电流对其浓度在1×10-7~5×10-4mol/L之间成良好的线性关系,检出限为4×10-8mol/L.对对苯二酚模拟品进行了测定,回收率在96.6%-99.6%之间.     

Dye-doped nanostructure polypyrrole film for electrochemically switching solid-phase microextraction of Ni(II) and ICP-OES analysis of waste water

A nanostructure fiber based on conducting polypyrrole synthesized by an electrochemical method has been developed, and used for electrochemically switching solid-phase microextraction (ES-SPME). The ES-SPME was prepared by the doping of eriochrome blue in polypyrrole (PPy-ECB) and used for selectively extracting the Ni(II) cation in the presence of some transition and heavy metal ions. The cation-exchange behavior of electrochemically prepared polypyrrole on stainless-steel with and without eriochrome blue (ECB) dye was characterized using ICP-OES analysis. The effects of the scan rate for electrochemical synthesis, uptake and the release potential on the extraction behavior of the PPy-ECB conductive fiber were studied. Uptake and release time profiles show that the process of electrically switched cation exchange could be completed within 250 s. The results of the present study point concerning the possibility of developing a selective extraction process for Ni(II) from waste water was explored using such a nanostructured PPy-ECB film through an electrically switched cation exchange.     

Properties and Electrochemical Behaviors of Oxide Coated Titanium Modified Electrode for Treatment of Organic Wastewater

In recent years, metal oxide Chemically Modified Electrode (CME) has been used for the electrochemical degradation of organic waste water. In this paper, a Ti/SnO₂+Sb₂O₃ CME was prepared and its chemical and electrochemical properties were studied.     

A Novel Cell Design for the Improved Stripping Voltammetric Detection of Zn(II), Cd(II), and Pb(II) on Commercial Screen‐Printed Strips by Bismuth Codeposition in Stirred Solutions

A novel electrochemical cell design is proposed to allow fast, reproducible and highly efficient convective transport of dissolved substances to screen‐printed electrochemical three‐electrode strips mounted on miniaturized plastic vessels, with the goal of improving detection limits in disposable electrochemical stripping field sensors. The experimental configuration has been tested for accumulation of the selected heavy metals ions Zn(II), Cd(II), and Pb(II), codeposited with bismuth ions on a carbon disk screen‐printed working electrode before detection by square wave anodic stripping voltammetry. Chemical and instrumental variables of the proposed device and associate electrochemical method were optimized. Selected parameters gave detection limits in the low ng mL^?1 range with moderate deposition time (120 s). Practical applicability was tested on certified water and real samples (tap water and waste water), with acceptable results, suggesting potential usefulness for field environmental monitoring of heavy metals.     

Electrode Reactions Involving Arsenic and Its Inorganic Compounds

The available information on the electrochemical properties of arsenic and its inorganic compounds is generalized. Processes of practical value are considered. These include the formation of free arsenic from solutions as a solid phase in the form of powder or galvanic coatings; the synthesis of arsine, arsenic acid, and arsenates; and use of electrochemical techniques for the waste water purification.     

Electrochemical Behavior of o‐Nitrophenol at Hexagonal Mesoporous Silica Modified Carbon Paste Electrodes

A hexagonal mesoporous silica (HMS) modified carbon paste electrode (CPE) was fabricated and characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods (ferrocene as a probe). The electrochemical behavior of nitrophenol (o‐NP) at the HMS modified electrode (HMSCPE) was investigated. Compared with CPE, a well‐defined reduction peak and a remarkably peak current response was observed. It is indicated that mesoporous HMS exhibited remarkable enhancement effects on the electrochemical reduction of o‐NP. The electrochemical reduction mechanism was also discussed. Consequently, a simple and sensitive electrochemical method was proposed for the determination of o‐NP, which was used to determine o‐NP in waste water samples.