Hydroxyl Free Radicals React With Inorganic Oxyacid Salt

Application of hydroxyl free radical strong oxidizing degradation of organic matter is one of the advanced oxidation technology emerging in recent years. Hydroxyl radical with extremely strong standard REDOX potentials, theoretically can most organic pollutants from water oxidation. At present in the water and on the reaction mechanism of organic matter is generally believed that is:seize the hydrogen effect, electron transfer function and the addition of three aspects. For hydroxyl free radicals and the role of various oxyacid salt is not study in detail.Based on the UV/H2O2 method to generate hydroxyl free radicals, under the system of hydroxyl radicals to join sulfate, carbonate, phosphate, and using double titration titration is only hydroxyl free radical system and mixed with various acid salt of hydroxyl free radical system between the difference of titrant, to prove that the system generated in the persulfate, carbonate and phosphate. Double titration method of cerium and iodine quantity method, method of cerium is a tetravalent cerium salt solution as titrant capacity analysis method. In acidic solution, Ce4+ and reducing agent, reduction of Ce3+, Eo (Ce4+/Ce3+)=1.61 v. Is REDOX titration by iodine volume method, a method is widely used, is using the I2 of oxidizing and reducing the I- on the basis of a oxidation-reduction method. Basic half reaction:I2+2e=2I-。In addition further by selecting the dye methyl orange, by observing the fading rate to infer that hydroxyl radicals and oxyacid salt system generates a new free radical, and the generated, sulfate radical and hydroxyl free radical oxidation. The different concentrations of sulfate to methyl orange chromophore is not very big, so come in Step to verify the sulfate radical EO=2.5 V to 2.5 V, almost with hydroxyl free radical (E0=2.7 V) equally oxidation ability.