The Research On Impact Of Pre-oxidation On Coagulation

By using batch static test, the effect of chemistry pre-oxidation on coagulation were researched. The raw water come from liujiang river. Oxidants evaluated included potassium permanganate(KMnO4), hydrogen peroxide(H 2 O 2 ), ozone(O 3 ), chlorine dioxide(ClO 2 ), and chlorine(Cl2). Effect of pre-oxidation on alum coagulation evaluated through the change of turbidity,TOC and UV254. The emphasis on some impact factors such as the kind or variety of oxidant and oxidant contact time were studied, with discussing the influence of pH and solution temperature. At the same time, theory of effect on pre-oxidation was analyzed.The experiment show that various oxidants had positive impacts of different degree on alum coagulation. Potassium permanganate(KMnO4) was found to be the most effective oxidant of the six investigated. Then the hydrogen peroxide(H 2 O 2 ). ozone(O3) was the most ineffective for increased the removal rate of turbidity,TOC and UV254 after alum coagulation. The most positive effect on alum coagulation must throw in the oxidant properly and enough contact time. Effect on pre-oxidation followed by alum coagulation can not be studied when the dosage of coagulation was excessive. The pH and Solution temperature had little effect on removal turbidity,TOC and UV254 by alum coagulation after pre-oxidation. Effect on removal of TOC was arised along with increase the removal rate of turbidity, but there isn't relation between UV254 and turbidity.