Pollution Research Paper

EFFECT OF PERSULFATE AND ACTIVATED PERSULFATE ON THE CHARACTERISTIC OF NATURAL ORGANIC MATTER FROM ALUM COAGULATION

EUIS NURUL HIDAYAH AND OKIK HENDRIYANTO CAHYONUGROHO

Abstract

Surface water is mainly used as source water for drinking water purposes, and it may contain natural organic matter (NOM), which causes some problems in water treatment. The economically feasible method to remove NOM is coagulation.However, NOM is still remaining after coagulation. The remaining NOM can be further removed by enhanced coagulation and pretreatment coagulation through preoxidation. Persulfate has received increasing attention due to its activation will generate sulfate free radical, the strongest oxidants with the highest oxidation potential. The objective of this study was to characterize and examine dissolved organic matter in source and treated water, through persulfate and activated persulfate only, coagulation preceded by persulfate preoxidation with and without activation. Source water samples from the river was treated by coagulation, preceded by preoxidation persulfate with and without ferrous ion activation. Sample were analyzed for dissolved organic carbon (DOC), ultraviolet light absorbance at 254 nm (UV254), specific UV absorbance (SUVA), and its functional group by using fouriertrans form infrared (FTIR). The results showed that coagulation preceded by activated persulfate generated the highest removal of DOC and UV254, and the relatively lower infrared absorption intensity than other treatments. It was conjectured that effect of the preoxidation by activated persulfate with ferro ion, which generated in situ-formed ferric ions, and alum coagulation contributed to the improved rejection of the organic compounds. Formation of sulfate radicals or in situ-formed ferric ions in activated persulfate without coagulation has a better performance to remove organic compound at 1200 cm-1 and 3440 cm-1 than alum coagulation only. This study concluded that activated persulfate could be used to enhance coagulation performance in removing organic matter in source water.