【作者】 朱正江；

【导师】 张乃东；

【作者基本信息】 大连海事大学 ， 环境科学与工程， 2012， 硕士

【摘要】 过硫酸盐氧化法是近些年来逐步兴起的新型高级氧化技术。过硫酸盐可分为过一硫酸盐和过二硫酸盐,与Fenton法相类似,普通过硫酸盐氧化法具有对有机物降解不彻底的缺点,例如酸性刚果红在Fe2+/过硫酸盐体系和Fenton体系中降解时都可形成一种较稳定的红棕色中间物,中间物褪色缓慢,导致TOC去除率不高,为克服这一缺点有必要研究光/过硫酸盐法,及其与光Fenton法的对比。实验中发现,刚果红降解的中间产物在紫外灯或日光照射下却能很快降解,并且日光的效果好于紫外灯,50μmol/L的酸性刚果红在模拟日光照射下60min脱色率为100%,120minTOC去除率为80.4%；UV灯照射下120min酸性刚果红脱色率为99%,TOC去除率为69.6%。为弄清日光法好于紫外法的原因,有必要研究光/过硫酸盐法降解水中刚果红的机理。文中以酸性刚果红为目标物,研究了其在光/Fe2+/过一硫酸盐、光/Fe2+/过二硫酸盐和光Fenton体系中的降解效率,具体考察了氧化剂浓度,亚铁离子浓度,pH值,刚果红浓度的影响。实验结果证明,无论是在日光还是紫外光照射下,酸性刚果红的降解速率都是过一硫酸盐>过二硫酸盐>过氧化氢；日光/Fe2+/过硫酸法好于UV/Fe2+/过硫酸法,日光Fenton法好于UV/Fenton法。日光法好于UV法的原因是,刚果红在降解时形成的中间体属醌亚胺类,醌亚胺类是光敏性物质,对可见光更敏感,在可见光辐射下发生光敏化反应,生成了单线态氧IO2和过氧自由基O2·-。O2·-在酸性条件下促进-OH和SO4-·的生成,导致体系中活性物质增多。更多还原

【Abstract】 The persulphate oxidation method was a new advanced oxidation technology, came forth recently. Persulfate could be divided into peroxymonosulfate and peroxysulphate. The organic could be thoroughly degraded using the common persulphate oxidation method, which was similar to Fenton method. For example, a relatively stable reddish brown substance was formed during acid Congo red degradation. Its formation causes the lower decolorization rates and TOC removal rates. It was necessary to study the sunlight/persulphate method for to overcome this drawback, and compare to Fenton method.It has been proved that sunlight/Fe2+/S2O82-method is superior to UV/Fe2+/S2O82-method in the process of acidic Congo red degradation. By using simulated sunlight/Fe2+/S2O82-method, the decoloring rate of acidic Congo red(50μmol/L) was up to100%after60min reaction and the TOC removal rate of acidic Congo red was up to80.4%after120min reaction, by using UV/Fe2+/S2O82-method, the decoloring rate of acidic Congo red got to99%after120min reaction while the TOC removal rate of acidic Congo red reached69.6%after120min reaction. It was necessary to study the degradation mechanism of acidic Congo red in sunlight/persulphate system for making clear the reason why sunlight method is superior to UV method.In this study, acidic Congo red was chosen as the model contamination to study the degradation rate in sunlight/Fe2+/peroxysulphate, sunlight/Fe2+/peroxymonosulfate and sunlight/Fenton system, and the effects of pH, the initial concentrations of Fe(II), oxidant on the degradation efficiencies of Congo red in sunlight were studied. The results have proven that regardless of whether sunlight or UV light the degradation rate of acidic Congo red as follow:peroxysulphate> peroxysulphate>hydrogen peroxide; sunlight/Fe2+/persulphate was superior to UV/Fe2+/persulphate and sunlight Fenton was superior to UV/Fenton method.The reason of why simulated sunlight/Fe2+/S2O82-method was superior than UV/Fe2+/S2O82-one was as follow:The results showed that the intermediate materials ofQuinonoids imine class could be generated in the process of degradation, and Quinonoids imine class has photosensitivity and is more sensitive to visible light; Quinonoids imine class is induced photosensitive reaction under visible light, which yielded singlet oxygen1O2and peroxy radical O2·-. O2·-can promote the generation of hydroxyl radicals·OH and sulfate radicals SO4-· in acidic condition, which can cause more active material to be produced in this system.更多还原