羟基自由基与无机含氧酸盐反应

发布时间：2018-01-02 23:00

本文关键词：羟基自由基与无机含氧酸盐反应　出处：《大连海事大学》2015年硕士论文　论文类型：学位论文

【摘要】：利用羟基自由基具有强氧化性可降解水中有机物,这种方法是近些年新兴的高级氧化技术之一。羟自由基的标准氧化还原电位极强,因此能氧化水中大部分有机污染物。目前对在水中与有机物的反应机理上普遍认为是：夺氢作用,电子转移作用和加成作用三个方面。而对羟自由基与各种含氧酸的自由基相互转化并不是研究的很详细。本文主要研究羟自由基与无机含氧酸盐(硫酸盐、碳酸盐、磷酸盐、硝酸盐)的作用,即研究羟自由基与无机含氧酸自由基的相互转化作用。本文通过UV/H2O2产生羟自由基方法,在羟基自由基体系下加入硫酸盐、碳酸盐、磷酸盐、硝酸盐,并运用双滴定法滴定比较只有羟自由基体系和加入各种酸盐的羟自由基混合体系之间的滴定液用量,来证明体系中生成了过硫酸盐、过碳酸盐、过磷酸盐及过硝酸盐,从而证明体系中有硫酸自由基、碳酸自由基、磷酸自由基及硝酸自由基产生。铈量法和碘量法即双滴定法,硫酸铈法是利用铈盐溶液作为滴定剂的容量分析法。在酸性溶液中,Ce4+与还原剂作用,被还原为Ce3+,E°(Ce4+/Ce3+)=1.61伏。碘量法是氧化还原滴定法中,应用比较广泛的一种方法,是利用的12氧化性和I-的还原性为基础的一种氧化还原方法。在双滴定法中,硫酸铈铵滴定原样品中的过氧化氢的量,而硫代硫酸钠则是滴定样品由于光照后产生的过氧酸盐的含量,因此通过分析两种滴定液的用量,即可证明体系中生成过氧酸盐,从而证明体系中有含氧酸自由基。另外又进一步通过选择染料甲基橙,通过观察其褪色率来推断证明羟基自由基与含氧酸盐体系生成了新的自由基,并且其中生成的硫酸根自由基与羟自由基氧化性相当。即不同浓度的硫酸盐对甲基橙的生色基团没有很大的影响,所以进一步验证了硫酸根自由基Eo=2.5V-3.1V几乎与羟自由基(Eo＝2.7V)有着同等的氧化能力。并将此方法应用于碳酸盐、磷酸盐和硝酸盐中。
[Abstract]:Using hydroxyl radical to degrade organic compounds in water is one of the new advanced oxidation techniques in recent years. The standard redox potential of hydroxyl radical is very strong. Therefore, most of the organic pollutants can be oxidized in water. At present, the reaction mechanism of organic compounds in water is generally considered as hydrogen capture. The interaction between hydroxyl radical and various oxygenated acids is not studied in detail. In this paper, hydroxyl radical and inorganic oxygenated salt (sulfate) are mainly studied. The interaction between hydroxyl radical and inorganic oxygenated acid free radical is studied. In this paper, UV/H2O2 is used to produce hydroxyl radical. Sulfate, carbonate, phosphate and nitrate were added in hydroxyl radical system. In order to prove the formation of persulfate and percarbonate, the titration amount between hydroxyl radical system and hydroxyl radical mixed system was compared by using double titration method. Perphosphate and pernitrate, it is proved that there are sulfuric acid free radical, carbonate radical, phosphate radical and nitric acid free radical in the system. Cerium sulfate method is a volumetric analysis method in which cerium salt solution is used as titrant. In acid solution, cerium 4 is reduced to Ce3 by interaction with reducing agent. E 掳Ce4 / Ce3 / Ce3 + 1.61V. The iodometric method is a widely used method in redox titration. It is a redox method based on 12 oxidizing and I-reductive properties. In double titration, ammonium cerium sulfate titrates the amount of hydrogen peroxide in the original sample. Sodium thiosulfate is the content of peroxyates produced in titrated samples due to illumination, so it can be proved by analyzing the amount of two kinds of titration solution to produce peroxyates in the system. It is proved that there are oxygen free radicals in the system. In addition, by selecting dye methyl orange and observing its fading rate, it is proved that hydroxyl radical and oxygenate system produce new free radicals. The oxidizing properties of sulfate radical and hydroxyl radical are the same, that is, different concentrations of sulfate have no great effect on the chromophore of methyl orange. It is further proved that the sulfate radical Eo=2.5V-3.1V has almost the same oxidation ability as the hydroxyl radical EoC 2.7V. and this method has been applied to carbonate. In phosphate and nitrate.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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