微波辐照辅助次氯酸盐氧化法制备高铁酸盐溶液

为克服高铁酸盐(Ferrate)溶液易分解和储存困难的缺点,发展了一种快速制备Ferrate溶液的新方法,即微波辅助次氯酸盐氧化法,利用微波辐照代替常用的水浴加热,实验发现该方法反应时间1分钟即可获得2~3g/L的高铁酸盐溶液,与单纯的次氯酸盐氧化法相比反应时间缩短了近50倍,且产品浓度较高。该方法快速简便、节能环保,有利于Ferrate溶液的现场制备及应用推广,为制备高铁酸盐开辟了一条新途径。     

电解法制备高铁酸盐的研究进展

综述了电解法制备高铁酸盐的研究现状,简要介绍其制备的原理,重点探讨了高铁酸盐制备过程中影响电流效率和高铁酸盐浓度的各种因素,分析总结了提高电解过程电流效率和提高高铁酸盐浓度的方法,为高铁酸盐的工业化应用提供理论依据。未来需要努力的方向,包括电极改进、稳定剂、超声波混合使用以及高铁酸盐制备工艺的优化,在低能耗下获得高浓度的高铁酸盐工业产品。     

电化学合成法制备高铁酸盐的研究进展

高铁酸盐是公认的“绿色”化学试剂,但制备成本过高大大限制了它的应用。电解法制备高铁酸盐以其工艺简单,原料消耗少而成为最可能商业化生产的方法。本文从电解槽结构、阳极材料组成、电解液的组成和浓度、电流密度、电解时间等各个方面阐述了影响电流效率和高铁酸盐产品浓度的因素。阳极室体积减小、电流密度和电解时间适当增加,可使Na2FeO4产品的浓度加大。阳极材料比表面积大,含有碳、硅的铸铁比纯铁活性高。新发展起来的惰性阳极法值得深入研究。电解液组分为氢氧化钠,浓度约为14mol/L时电流效率较高,电解液中添加适当的氧化剂或腐蚀性离子有助于减少阳极钝化和稳定高铁酸根离子。交直流叠加的加电方式有利于缓解阳极钝化现象。文章指出,未来需要设计新型合理的电解槽结构和研发新的生产工艺,降低电耗和电解液浓度,提高电流效率,最终达到长时间连续生产高浓度高铁酸盐的目的。     

水处理剂高铁酸钠的制备

本实验在分析各种制备高铁酸盐方法的基础上,采用无机化学次氯酸盐氧化法制备高铁酸钠,并着重分析了各种不同因素Fe（NO3）3·9H2O的用量、碱的用量、原料的添加顺序）对产率的影响,并分析了高铁酸盐在水处理方面的应用。     

高铁酸盐在水处理中的研究进展

高铁酸盐是一种集氧化、絮凝、杀菌多种功能为一体的新型高效多功能水处理剂,高铁酸盐水处理剂兼有较强的氧化性和优良的絮凝功能且在杀菌方面依旧表现优异,且相较于物理吸附法更不易产生二次污染,相较于传统氧化剂,高铁酸盐更为安全,在水处理领域有广阔的应用前景。与使用传统方法合成高铁酸盐相比,本文讨论了高铁酸盐的原位生成方法的优势及其在工业应用方面的价值;对于制约高铁酸盐工业应用发展的稳定性问题,文中分析了影响高铁酸盐稳定存在的温度,pH,溶液中所含有的各种离子浓度等各种因素,综述了提高固态和液态两种形式的高铁酸盐稳定性的方法;最后总结了高铁酸盐在水处理方面的应用进展,对于高铁酸盐工业推广应用中存在的问题进行了探讨。     

高铁酸盐分析方法研究进展

高铁酸盐可以用作超铁电池储能阴极材料,也是新型绿色有机合成氧化剂和水处理药剂.日益广泛的应用需要精准的分析测试方法.综述了高铁酸盐的定性、定量分析方法,包括红外光谱、紫外可见光谱、滴定分析、XRD、穆斯堡尔谱、电化学分析、荧光分析法等,详述了分析方法原理及适用范围.     

绿色功能材料高铁酸盐的制备及其应用研究进展

介绍了高铁酸盐的性能,概括了高铁酸盐国内外应用现状,综述了高铁酸盐的制备和分析方法,讨论了高铁酸盐在制备过程中所存在的问题和改进建议。     

双效水处理剂高铁酸盐的研究进展

高铁酸盐是一种集氧化杀菌、絮凝去污为一体之安全、双效的水处理絮凝剂。综述了高铁酸盐独特的性能、制备方法及应用研究进展,讨论现有制备方法的局限性并提出展望。     

电化学制备高铁酸盐及其氧化降解对硝基苯酚的研究

采用中端设立离子隔膜缓冲室的电解槽制备高铁酸盐,以直径为1.2 mm的细铁丝为阳极,铜片为阴极,探索了不同缓冲室容积与时间对高铁酸盐产率的影响,在一定电解条件下可得浓度为43.33 mmo·L-1的高铁酸盐,并以此产物氧化降解对硝基苯酚模拟废水.结果表明,高铁酸盐具有良好的氧化降解对硝基苯酚的性能,当高铁酸钾与对硝基苯酚的摩尔比为7:1时,反应10 min后对硝基苯酚COD去除率达到60.64%;通过GC/MS分析反应产物,对硝基苯酚能够有效地去除.     

高铁酸盐控制饮用水中消毒副产物的研究进展

消毒是饮用水处理中特别重要的一步。随着工农业经济的飞速发展,水源中检测出大量种类复杂的有机污染物质,在消毒过程中这些有机物与消毒剂反应会产生一些对人体健康具有潜在危害的消毒副产物(DBPs),例如三卤甲烷、亚氯酸盐、溴酸盐等。因此,能否有效控制DBPs的产生成为了评价饮用水消毒质量效果的一项重要指标,而去除消毒副产物前体物是控制DBPs产生的关键。高铁酸盐作为一种绿色高效的新型水处理剂,具有强氧化还原能力,处理后的水中基本不会产生DBPs且能有效地抑制一些常见DBPs。文中综述常见的DBPs及前体物的种类、DBPs控制方法以及高铁酸盐在饮用水处理中对DBPs的控制。     

Research progress in the electrochemical synthesis of ferrate(VI)

There is renewed interest in the +6 oxidation state of iron, ferrate (VI) (Fe^VIO₄²⁻), because of its potential as a benign oxidant for organic synthesis, as a chemical in developing cleaner (“greener”) technology for remediation processes, and as an alternative for environment-friendly battery cathodes. This interest has led many researchers to focus their attention on the synthesis of ferrate(VI). Of the three synthesis methods, electrochemical, wet chemical and thermal, electrochemical synthesis has received the most attention due to its ease and the high purity of the product. Moreover, electrochemical processes use an electron as a so-called clean chemical, thus avoiding the use of any harmful chemicals to oxidize iron to the +6 oxidation state. This paper reviews the development of electrochemical methods to synthesize ferrate(VI). The approaches chosen by different laboratories to overcome some of the difficulties associated with the electrochemical synthesis of ferrate(VI) are summarized. Special attention is paid to parameters such as temperature, anolyte, and anode material composition. Spectroscopic work to understand the mechanism of ferrate(VI) synthesis is included. Recent advances in two new approaches, the use of an inert electrode and molten hydroxide salts, in the synthesis of ferrate(VI) are also reviewed. Progress made in the commercialization of ferrate(VI) continuous production is briefly discussed as well.     

The rapid electrochemical preparation of dissolved ferrate(VI): Effects of various operating parameters

The preparation of ferrate(VI) by the anodic dissolution of an iron wire gauze in concentrated NaOH solution is described. An anolyte of 0.35-0.48 M Na₂FeO₄ can be produced during 3-6 h electrolysis in initial 16 M NaOH solution at 35 °C. The experimental results indicate that the Fe(VI) concentration variation rate during electrolysis is close related to the factors such as current density, alkaline concentration, the ratio of effective surface area to anolyte volume, the passivation of iron anode and the decomposition of ferrate(VI), etc., and the relevant empirical equation is given. The alkalinity of anolyte has large effect on the electrogeneration of ferrate(VI), especially during an interval electrolysis.     

Decolorization of azo dye Orange II by ferrate(VI)-hypochlorite liquid mixture, potassium ferrate(VI) and potassium permanganate

Ferrate(VI)-hypochlorite liquid mixture was prepared using hypochlorite, an industrial by-product, via wet oxidation method. Its oxidizing ability was investigated by decolorizing azo dye Orange II in batch experiments, and compared with potassium ferrate(VI) and potassium permanganate. Effects of the oxidant concentration, dye concentration, initial pH of dye solutions and UV 254 nm irradiation were examined. The color removal by potassium permanganate, potassium ferrate(VI) and the ferrate(VI)-hypochlorite liquid mixture at 30 min reached 17.7%, 62.0% and 95.2%, respectively. The ferrate(VI)-hypochlorite liquid mixture maintained a high decolorization efficiency over a wide pH range from 3.0 to 11.0, indicating that the initial solution pH had little impact on its oxidizing power. However, the decolorization efficiency by potassium permanganate was proved to be highly pH dependent and the lowest efficiency was observed at neutral pH. UV 254 nm irradiation did not enhance the decolorization efficiencies significantly for both the ferrate(VI)-hypochlorite liquid mixture and potassium permanganate over a wide pH range.     

高铁酸盐的合成及应用研究进展

高铁酸盐具有固体盐稳定、氧化还原电位高、比容量高、放电产物对环境无污染和选择性氧化好等一系列优点,在生活及生产中得到了广泛的应用。本文评述了高铁酸盐的3种合成方法,以及作为多功能水处理剂、选择性氧化剂和绿色环保电池的电极材料应用的新进展,并对其应用前景进行了展望。     

聚磷酸铵合成方法的研究进展

系统介绍了聚磷酸铵的生产方法,包括磷酸二氢铵法、磷酸-尿素法、磷酸脲法、磷酸二氢铵-尿素法、磷酸氨化法和磷酸铵-五氧化二磷法。磷酸二氢铵法、磷酸-尿素法、磷酸氨化法得到的产物聚合度较低,低聚合度聚磷酸铵水溶性高,呈中性,适宜作农用肥料;磷酸二氢铵-尿素法和磷酸铵-五氧化二磷法得到的产物聚合度较高,高聚合度聚磷酸铵适宜作阻燃剂。     

石膏晶须制备的研究进展

介绍了目前石膏晶须的制备方法,重点阐述了在湿法磷酸生产中制造石膏晶须的绿色化学工艺。     

Ultrasonic-assisted convenient chemical synthesis of battery grade potassium ferrate(VI)

An ultrasound-assisted convenient method was developed for the synthesis of battery grade potassium ferrate (K₂FeO₄) with high yield (53-59%). The purity of the synthesized salt was determined by chromite method to be 95-96.8%. It was found that sample of the solid potassium ferrate has a tetrahedral structure with a space group of D_2h (Pnma) from X-ray diffraction (XRD) spectrum. From the scanning electronic microscopy (SEM), the K₂FeO₄ powders were crystallized polyhedron-shaped stick, and the particles had dimensions on the order of 25-200 μm in length and 1-10 μm in width. The electrochemical performance of the K₂FeO₄ electrodes was studied by using cyclic voltammetry and galvanostatic discharge methods in 10 mol/L KOH aqueous electrolyte. The synthesized product possesses a capacity of 302.4 mAh/g and coulombic efficiency of 74.5%.     

聚苯胺纳米纤维制备方法的研究进展

聚苯胺(PANI)纳米纤维同时具有PANI优异的物理、化学性能以及纳米纤维特有的小尺寸效应,在生产和生活领域中具有潜在的应用前景。PANI纳米纤维制备方法主要包括物理法、化学法、电化学法和综合法等。综述了不同方法的制备原理、优势及存在的问题,重点介绍了化学法中的种子聚合法、界面聚合法和乳液聚合法,并预言综合使用各种聚合法将成为制备PANI纳米纤维的趋势。