Study On Removal Of Aniline Of Wastewater By Oxidation Method

It is a difficult problem to be solved to treat the high concentrated industrial wastewaterin the field of environmental protection techniques in our country, especially, of anilinecategory wastewater. The oxidation methods by using chlorine dioxide and Fenton reagentwere applied to teat the aniline wastewater in laboratory level studies in this thesis.Chlorine dioxide was employed to treat aniline in these experiments. The effects ofreaction time, pH, temperature and ClO₂ dosage on removal efficiency of aniline wereinvestigated, and the optimum conditions were determined as: pH5.8, dosage ratio betweenClO₂ and aniline was 10: 3, reaction time was 30 min and the reaction temperature 35℃when the highest removal efficiency of aniline reached 73.26%. Moreover, the intermediateproducts formed in the reaction processes were studied too. It was found that the mainintermediate product was benzoquinone which could be removed by ClO₂ when the reactionconcentration ratio between ClO₂ and aniline was 7:1.Application study on wastewater treatment with Fenton reagent oxidation method is animportant direction of environmental science researches and is also an important method ofwastewater with chemical oxidation method. However, today only conventional Fentonreagent oxidation method is widely applied in industry. In this paper, aniline categorywastewater treatment with Fenton reagent oxidation method is systematically studied. Somefactors that influence the removal rate of aniline containing, were investigated, and theoxidation mechanism of aniline by Fenton reagent was discussed and analyzed. When theconcentration of aniline was 50mg/L at pH3, the reaction concentration ratio of H₂O₂ and Fe²⁺ was 10:1, the experimental result indicated that the removal efficiency of aniline couldreached 97.32% at the temperature under 35℃. The effluent can be easily treated byconventional biochemical method.Moreover, the effect of inorganic ions on the catalytic oxidation ability of Fenton reagentwas also observed. This study selects some represent inorganic ions to investigate the effectof them on the degradation of aniline with Fenton reagent. Results show that ferric ions canenhance the catalytic oxidized ability of Fenton reagent. Phosphate, chloride ions andbicarbonate ions will suppress the catalytic oxidized ability, and the inhibition ability of theseions is ranked as: H₂PO₄＞Cl^-＞HCO₃^-. On the other hand, the action mechanics of inhibitionof the inorganic ions is discussed too.