电化学氧化处理难降解废水的研究进展

综述了国内外电化学氧化处理难降解废水的研究现状,详细阐述了电化学氧化机理,包括阳极氧化技术和阴极还原技术,介绍了影响电化学氧化降解效率的主要因素,包括电极材料、电化学反应器、溶液的pH值、溶剂体系以及其它因素.从有机污染物电化学氧化机理的研究、电极材料的研制、电板结构的研究和高效电解反应器的开发、对特定的电化学氧化系统...     

三维电极在废水处理中的应用研究

综合近年来国内外有关三维电极电化学废水处理技术研究文献,概述了三维电极在废水处理中的应用研究进展和特点,对三维电极在处理重金属离子废水、有机废水等方面的应用进行了论述,同时也对三维电极与其它技术的结合使用进行了总结,并提出三维电极目前在应用研究方面存在的问题及今后的研究方向。     

电化学技术处理油田污水的研究进展

对油田污水的性质、组成及危害进行了简要叙述。介绍了利用电化学技术处理油田污水的原理,以及目前国内外应用的主要方法,包括微电解法、电解气浮法和电化学氧化法等。分析了电化学技术用于油田污水处理的优缺点,如高效、清洁、安全,但能耗较高,电极材料的稳定性、活性和寿命较低。综述了电化学技术处理油田污水的研究和应用进展,提出了电化学处理油田污水的研究重点和改进方向,主要包括电化学技术与其他化学方法联合处理,发挥协同作用,改善处理效果;研发特殊的电化学处理设备,提高处理效率;开发低成本、高催化活性和使用寿命稳定长久的电极材料,通过电化学氧化技术提高有机难降解物质的处理效果;将新型清洁能源与电化学技术相结合,降低处理能耗。     

废水中难降解污染物电化学处理技术研究进展

介绍了电化学氧化法、电絮凝法、电沉积法、电浮法与微电解法等五种常见的电化学污染物处理方法及其在废水处理中的研究进展,分析了电化学技术在废水处理过程中存在的一些问题,探讨了电化学技术反应机理研究、电极材料研发、新型反应器研发以及联用技术研发等未来潜在的研究方向。     

电化学高级氧化技术在工业废水处理中的应用

综述近年来电化学高级氧化技术在纺织工业废水、制革废水、石油化工废水、造纸工业废水及其它食品、医药等实际工业废水处理中的应用进展,为采用电化学高级氧化技术处理类似工业废水时选取最佳的运行条件提供参考;并提出开发低成本电极材料、提高规模化应用、减少有毒副产物的生成以及电化学与常规工艺组合运行将是未来研究的重要方向。     

电化学高级氧化技术在工业废水处理中的应用

综述近年来电化学高级氧化技术在纺织工业废水、制革废水、石油化工废水、造纸工业废水及其它食品、医药等实际工业废水处理中的应用进展,为采用电化学高级氧化技术处理类似工业废水时选取最佳的运行条件提供参考;并提出开发低成本电极材料、提高规模化应用、减少有毒副产物的生成以及电化学与常规工艺组合运行将是未来研究的重要方向。     

废水中难降解污染物电化学处理技术研究进展

介绍了电化学氧化法、电絮凝法、电沉积法、电浮法与微电解法等五种常见的电化学污染物处理方法及其在废水处理中的研究进展,分析了电化学技术在废水处理过程中存在的一些问题,探讨了电化学技术反应机理研究、电极材料研发、新型反应器研发以及联用技术研发等未来潜在的研究方向。     

电化学过滤技术的研究现状与展望

通过对电化学过滤技术中采用的颗粒状、网块状、涂层状以及网膜状电极材料进行比较,提出以碳纳米管(carbon nanotube,CNT)及其表面改性和功能化应用的膜电极材料是电化学过滤技术中电极材料的良好选择。概述了改性商用聚碳酸酯外壳反应器、CNT/陶瓷基电极化膜(EM)反应器、CNT/Al2O3基膜组件反应器、CNT-聚偏氟乙烯(polyvinylidene fluoride,PVDF)五层多功能复合电极反应器4种典型电化学过滤反应器和电化学过滤技术处理效果的影响因素,并指出以CNT为代表的三维网膜状电极材料的开发、利用与再生是未来电化学过滤技术研究的重点。     

电化学还原处理含氮化合物研究现状与展望

根据电极材料的不同,分别就硝酸盐、氮氧化物、硝基苯的电还原技术发展进行了论述,并介绍了电化学还原技术中的几种反应器。指出电极材料是影响电化学还原效果的关键因素,开发改性多金属电极和复合薄膜电极已成为电化学还原含氮化合物研究一种趋势。未来的研究重点主要在成本低、对还原产物具有选择性的电极开发,基于三维电极材料的电化学过滤反应器设计,及电极材料的耐久使用和保养再生方面。     

电化学过滤技术的研究现状与展望

通过对电化学过滤技术中采用的颗粒状、网块状、涂层状以及网膜状电极材料进行比较,提出以碳纳米管(carbon nanotube,CNT)及其表面改性和功能化应用的膜电极材料是电化学过滤技术中电极材料的良好选择。概述了改性商用聚碳酸酯外壳反应器、CNT/陶瓷基电极化膜(EM)反应器、CNT/Al2O3基膜组件反应器、CNT-聚偏氟乙烯(polyvinylidene fluoride,PVDF)五层多功能复合电极反应器4种典型电化学过滤反应器和电化学过滤技术处理效果的影响因素,并指出以CNT为代表的三维网膜状电极材料的开发、利用与再生是未来电化学过滤技术研究的重点。     

Preparation of carbon micro-coils involving the decomposition of hydrocarbons using PACT (plasma and catalyst technology) reactor

Carbon micro-coils as well as carbon fibers with various morphologies were prepared by the decomposition of hydrocarbons, such as acetylene, methane, propane, ethylene, etc., at 770°C using a PACT (plasma and catalyst technology) reactor. The preparation conditions, growth mechanism and morphology of the carbon micro-coils were examined. The Ni electrode of the PACT reactor was used as the catalyst as well as a plasma source electrode. It was found that hydrocarbons, such as methane, propane and ethylene, decomposed under the plasma and catalyst atmosphere to form acetylene as the main decomposition product, and then this acetylene was further decomposed to form carbon micro-coils. Using a Ni powder catalyst dispersed on the substrate, the carbon micro-coils with a double helix structure, in which two pieces of carbon coils entwine each other in the same coiling direction, grew among the single straight carbon fibers and paired straight fibers. On the other hand, the carbon micro-coils with a single helix structure and wide coil pitch were obtained by the indirect decomposition of acetylene using the N₂ plasma formed by the PACT reactor.     

Studies on the effect of electrode type and substrate temperature on plasma polymerization of two model compounds: Acrylonitrile and hexamethyldisiloxane

Polymers were prepared from saturated (HMDS) and unsaturated (AN) monomers in a radio frequency discharge (plasma). The effect of selected parameters such as electrode type (such as Cu, Zn, Ni, Al), reactor type, and substrate temperature (other parameters constant) on chemical structure and the rate of polymer deposition was examined by Fourier transform infrared (FTIR) spectroscopy. Differences in the nature of electrodes and reactor types were found to yield similar plasma products with similar rates of deposition for two monomers. In the tubular reactor used, deposition rates were observed to decrease with increasing substrate temperatures showing different dependencies on temperature for the monomers tested.     

三维电极电化学反应器处理青霉素釜残废液的研究

青霉素在其生产过程中排放出高浓度有机发酵釜残废液,该废液COD浓度高,成分复杂,可生化性差,是环境工程领域的研究难题。提出一种基于三维电极电化学反应器处理青霉素釜残废液的新技术,实验表明,用三维电极电催化氧化处理釜残废液有较好的处理效果。     

三维电极技术及其在环境污染治理中的应用

介绍了三维电极技术的分类和工作机理。综合近年来国内外三维电极技术的研究文献,重点阐述了三维电极技术在三维电极反应器、极板材料、粒子电极及与其它技术联用的研究现状,概述了三维电极技术在废水处理和废气治理领域的应用状况。高效反应器和新型三维电催化电极的研制及其联合处理工艺的开发将成为今后该领域研究的重点方向。     

限碳背景下燃煤电厂对策分析与电化学催化还原技术进展

分析了目前CO₂减排的压力和趋势,以电化学催化还原为技术核心,结合燃煤排放特点,对电化学体系进行了优选,提出限碳背景下燃煤电厂的减排策略。在缓解日益严峻的CO₂减排和温室效应问题的同时,将大体量废弃的CO₂转化为具有利用价值的产品是碳捕集与利用的必由之路。对CO₂电化学催化还原技术的过程原理进行简要阐述,围绕电极、电解质、CO₂溶解性、反应器形式进行讨论,结合电化学催化还原技术特点和燃煤电厂结构特征,对大体量、低浓度CO₂电化学催化还原条件进行筛选,确定了以Cu基气体扩散电极-离子液体-连续式反应器为核心的基本电化学体系,进而提出燃煤电厂烟气中CO₂电化学催化还原对策,但在向实际应用转化过程中该技术仍面临非理想气源中杂质的影响、还原电流密度低引发的产物生成速率慢、电极寿命短、产物多样性伴随的分离及提纯难度大等障碍,为面向应用的技术发展指明了研究方向。     

三维荧光光谱法用于监测两种农药的电化学降解

该文通过填装粒子电极的三维电极反应器对水中敌敌畏、乐果的农药污染物进行了催化降解过程的研究。通过三维荧光光谱,探讨了单一污染物、混合污染物及进水pH等影响因素对两种农药有效成分的去除效果。结果表明三维荧光光谱可以很好地监测反应过程中有机物的变化规律,通过三维荧光光谱可以直观地了解水中有机污染物降解过程中主要污染物的浓度变化、反应程度、反应产物类型等各类信息。三维荧光光谱法能很好地应用于水中有机农药的监测。     

Electrochemical denitrification of metal-finishing wastewater: Influence of operational parameters

Experimental results are presented for the electrolytic ChemDen (Chemical-Denitrification) process which was designed to investigate the effect of operational parameters on the nitrate (NO₃⁻) removal from metal-finishing wastewater. The parameters included electrode materials, electrode gap, reducing agent, hydraulic retention time (HRT) and recycle ratio in the single electrolytic ChemDen reactor for lab-scale tests. The removal efficiency of nitrate is based upon a non-biological process which consists of chemical and electrolytic treatment. Results showed that removal efficiency of nitrate was highest when the zinc (Zn) electrodes were used for both anode and cathode. In the case of insoluble electrode, combining Pt anode with Ti cathode provided great improvement of nitrate removal. For the Pt-Ti electrode combination, increasing electrode gap tended to increase removal efficiency of nitrate significantly. However, no further increase in the nitrate removal was observed when the electrode gap was longer than 10mm. Using sulfamic acid and Zn metal powder as reducing agents for the electrolytic ChemDen reaction, highest nitrate removal was achieved when the mole ratio of Zn: sulfamic acid: nitrate was 1.2: 1: 1. Remarkable improvement in the nitrate removal was also observed with increasing HRT from 10 to 30 min, while the effectiveness was limited when HRT was increased to 60 min. Recycling in electrolytic ChemDen reactor affected nitrate removal positively because it could improve both dispersion and reuse of Zn metal powder as reducing agent in the reactor. Recycling effects were thought to be associated with increasing surface reactivity of the Zn metal powder in the electrolytic ChemDen reactor.     

Advances in Nano-Structured Electrochemical Reactors for NOx Treatment in the Presence of Oxygen

Dramatic improvements in the selective separation and purification of NO_x in exhaust gases by an electrochemical reactor have been achieved. The novel electrochemical cells for NO_x decomposition were developed by nano-scale control of penetrating pores from the catalytic electrode surface to the bottom of the catalytic electrode layer, and by distribution at the interfaces of ionic and electronically conducting grains through the electro-catalytic electrode of the cells. Dramatic improvement in the current efficiency and suppression of the working voltage of the cells enabled their application as a novel reactor for NO_x decomposition of gases from gasoline- and diesel-engine vehicles, gas engines, and other industrial equipment with the advantage of less energy consumption in comparison to "the fuel penalty" for presently used catalytic systems. The cells are able to work as a deNO_x reactor even under excess oxygen contents up to 10% because of the selective separation to NO_x molecules by the nano-space reaction. For the first time such nano-reaction has been shown to realize sufficiently applicable yielding rates. Enlarged cells revealed high performance similar to the small experimental cells.     

Segmented thin-gap flow cells for process intensification in electrosynthesis

Design calculations are presented for a single-pass high-conversion electrochemical reactor suitable for process intensification in electroorganic synthesis. The key feature of the design is the use of a segmented working electrode, combined with a small anode—cathode gap. Each working electrode segment is operated at an optimal local current density, defined with respect to the local diffusion—limited current density of the reacting species. Two reactor configurations are considered:(i) an adiabatic reactor, and (ii) an isothermal reactor with integrated heat exchange. Calculated results for the devices in a classical electroorganic synthesis system, the methoxylation of 4-methoxy-toluene, are presented and the general features and performance characteristics of the cell are compared with those of a more conventional capillary-gap cell, currently used industrially. For an electrode gap of 0.1 mm, the average current density attainable in the novel design is of the order of 2700 A m⁻² in the adiabatic reactor and of the order of 7100 A m⁻² in the isothermal reactor, respectively, 5 and 14 times higher than the current densities applied in the current industrial process. In addition to process intensification, other advantages of the proposed technology are the absence of reactant recycle, short residence times and plug flow of the reagents, all of which contribute to improved process selectivity.