Oxidation Susceptibility Of Hydroxyl Radical During Ozonation

Parachlorobenzoic-acid has long been used to measure the hydroxyl radical as probe compound. It was found to bring error when Parachlorobenzoic-acid is used to be the target, so to choose several organic compounds with different structures for studying in order to find some suitable new compounds. Intermediates in different oxidizing method were detected so as to analyze the possible oxidative pathway and avoid the bad byproducts. Whereas the environmental toxicity of the intermediate formaldehyde, which was studied as object. Following results have been obtained:Succinic acid and malonic acid were found to be suit for target after a lot experiments. They are non-toxic compounds and harmlessness that are familiar binary carboxylic acids. Succinic acid was used as target during ozonation of chlorophenol, whose concentration was measured by ion chromatography. Variation of concentration of hydroxyl radical was computed.Oxidation by ozone alone and mixed oxidation by ozone/hydroxyl radicals were taken individually in ozonation of solution of nonylphenol. Both could degraded nonylphenol effectively, nonylphenol was wiped off in the setting time. Hydroxyl radicals could increase the economic efficiency hugely during ozonation of nonylphenol. Mixed ozonation has higher degree of oxidation than ozonation by ozone alone.Humic acid and glucose were used to simulate the natural water to be oxidized. Take Succinic acid and malonic acid as target, it is found that glucose didn't restrain producing hydroxyl radicals or accelerate to product but humic acid would accelerate to produce hydroxyl radicals.Experiments about effect of yield of formaldehyde cause by different pollutants structure,oxidative pathway and oxidative conditions were done. Benzene with different substituents in the ring would affect the yield of formaldehyde, especially for monoolefin, the group connected to theα-C would affect more seriously. The yield of formaldehyde of aliphatic saturated hydrocarbon was a fat lot which could be neglected. Take crylic acid solution as object, the concentration of formaldehyde showed increasing followed decreasing with a peak. When augment the inlet flux, the original yield rate of formaldehyde would increase during oxidizing crylic acid solution, and the peak value of concentration of formaldehyde would decrease and bring forward. So did angment of concentration of gaseous ozone. Augment of hydroxyl radicals would be propitious to ringopening of nonylphenol and salicylic acid so as to yield more intermediate product; C=C structure would be propitious to addition reaction of ozone, and the augment of hydroxyl radicals increased percent mineralization.