OZONE, OXALIC-ACID, AND ORGANIC-MATTER MOLECULAR-WEIGHT - EFFECTS ON COAGULATION

Ozonation breaks long chain natural organic matter (NOM) into smaller, more oxygenated compounds such as oxalic acid. The purpose of this st udy was to evaluate the effects of such transformations on coagulation in high dissolved organic carbon synthetic waters with model particle s. Results indicate that the presence of oxalic acid adversely affects the removal of turbidity and organic carbon by coagulation and filtra tion. The results also show that larger (higher molecular weight) orga nic matter is easier to remove by coagulation than lower molecular wei ght organic matter. In both cases, ozonation results in an increase in the optimum coagulant dose or a decrease in the amount of turbidity a nd TOC removal at a given coagulant dose.