零价铁活化过硫酸钠降解甲基橙

Decolorization Properties of Methyl Orange by Sodium Persulfate Activated with Zero-Valent Iron

利用零价铁活化过硫酸钠产生的硫酸根自由基作氧化剂降解偶氮染料甲基橙.研究了不同因素对目标污染物降解效率的影响,其中包括零价铁的加入量、过硫酸钠的浓度、温度、pH等.实验结果表明:当单独投加零价铁的甲基橙溶液,其甲基橙的降解率只有2.99%;而单独加入过硫酸钠时,降解率达到51.81%,在酸性和中性的条件下过硫酸钠都会发生水解,生成硫酸根基使溶液的氧化性增强,从而使甲基橙褪色.当pH值为3.0时、温度为30℃、铁的加入量为11.2mg/L、过硫酸钠的浓度2.0mol/L时,在60min降解率达到最大约为94%.同时还比较了零价铁、过硫酸钠、温度和不同pH条件对甲基橙降解效率的影响大小,结果表明前30min时温度和零价铁的量对降解的影响最大,其影响大小为:温度>铁的加入量>pH>过硫酸钠浓度.而在后30min时,降解的速率缓慢,温度和pH成为主要影响因素,影响大小为:温度>pH>过硫酸钠浓度>铁的加入量.

Using the zero-valent iron activated persulfate,sulfate radical oxidant degradation of azo dye methyl orange was produced.The effects of different factors on the degradation efficiency of target pollutant are studied,including the amount of zero valent iron,sodium persulfate concentration,temperature,pH and so on.The experimental results show that：when the dosage of methyl orange solution alone zero valent iron,the removal of methyl orange was only 2.99%;while adding sodium persulfate,the removal rate reached 51.81%,in acidic and neutral conditions will be hydrolyzed to produce sulfuric acid sodium persulfate oxidation solution enables enhanced,so that the methyl orange fade.When pH is 3,temperature is 30℃,iron the amount of 11.2mg/L,2.0mol/L concentration of sodium persulfate,the degradation rate of 60 min reached a maximum of about 94%.At the same time also compared with zero-valent iron,sodium persulfate,temperature and pH of different conditions on the degradation efficiency of methyl orange.Ring size,the results of the study show that 30 min before the effects of temperature and the amount of zero-valent iron on the degradation of the maximum magnitude of the effect is：temperature〉the amount of iron in〉 pH.After 30 min of sodium persulfate,the degradation rate is slow,temperature and pH become the main factors that affect the effect of size：the amount of iron concentration〉temperature〉pH〉sodium persulfate.