Pre Oxidation Effect on Total Organic Carbon (TOC) Removal in Surface Water Treatment in Iran Case Study: Tehran Pars Water Treatment Plant

摘要

In drinking water treatment, pre-disinfection are often applied in order to control microorganisms and taste-and-odor-causing materials, which may influence organics removal by pre-oxidation and adsorption. Using commercial and natural water humic substances, the positive effect of pre-chlorination and pre-ozonation as an aid to coagulation-flocculation of these compounds were confirmed by removal of Total Organic Carbon removal in Tehran city. These experiments were conducted at bench-scale through a series of jar test using different pH, coagulant dosage and total organic carbon concentration of approx. 4, 8 and 12 mg/L. In addition to TOC removal the existence of an optimum pre-ozonation dose and an optimum pre-chlorination dose were also confirmed. Experiments show that pre-chlorination and pre-ozonation can improve of coagulation and flocculation depended on TOC concentration of influent surface raw water. The results demonstrate differential effect between pre-chlorination and pre-ozonation on removal of TOC. Pre-ozonation showed a positive effect on a system with low influent TOC and very low molecular weight (noncolloidal) humic substances.