1,4-Dioxane is an EPA priority pollutant often found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to decompose this compound effectively. Therefore, an advanced oxidation process system (AOP) was used for the degradation of 1,4-dioxane. This research investigates the effect of adding oxidants, such as ozone, air, and H2O2 during the UV irradiation of 1,4-dioxane solution. In order to analyze 1,4-dioxane, a modified 8270 method, which is an improved method of U.S EPA 8720, was used. Degradation efficiencies of 1,4-dioxane by only UV irradiation at various temperatures were not significant. However, The addition of oxidants and air bubbling in the UV irradiation system for 1,4-dioxane decomposition showed the higher 1,4-dioxane degradation rate. And, during AOP treatment the tendency of TOC changes was similar to that of 1,4-dioxane decomposition rate.

We compared the applicability and economical efficiency of peroxone process with those of ozone process in the existing water treatment plant on downstream of Nakdong River. After comparing the peroxone process for removing geosmin with the ozone process in lab scale test, peroxone process showed much higher removal efficiency than the ozone process at the same ozone dosage. Proper range of H2O2/O3 ratio were 0.5~1.0 and the half-life of geosmin was about 5.5~6.8 min when the H2O2/O3 ratio was set to 0.5 during 1~2 mg/L of ozone dosage. Peroxone process could reduce the ozone dosage about 50 to maximum 30% for the same geosmin removal efficiency compared to the ozone process in the pilot scale test. In case of 1,4-dioxane treatment, peroxone process could have 3~4 times higher efficiency than ozone process at the same ozone dosage. The results of estimating the economical efficiency of ozone and peroxone process for treating geosmin and 1,4-dioxane by using pilot scale test, in case of the removal target was set to 85% for these two materials, the cost of peroxane process could be reduced about 1.5 times compared to ozone process, and in the same production cost peroxone process could have 2~3 times higher removal efficiency than ozone process. The removal efficiency by peroxone process showed a large difference depending on the physicochemical characteristics of target materials and raw water, therefore detailed examination should be carried out before appling peroxone process.

Advanced oxidation processes involving O3/H2O2 and O3/catalyst were used to compare the degradability and the effect of pH on the oxidation of 1,4-dioxane. Oxidation processes were carried out in a bubble column reactor under different pH. Initial hydrogen peroxide concentration was 3.52 mM in O3/H2O2 process and 115 g/L (0.65 wt.%) of activated carbon impregnated with palladium was packed in O3/catalyst column. 1,4-dioxane concentration was reduced steadily with reaction time in O3/H2O2 oxidation process, however, in case of O3/catalyst process, about 50～75% of 1,4-dioxane was degraded only in 5 minutes after reaction. Overall reaction efficiency of O3/catalyst was also higher than that of O3/H2O2 process. TOC and CODCr were analyzed in order to examine the oxidation characteristics with O3/H2O2 and O3/catalyst process. The results of CODCr removal efficiency and ΔTOC/ΔThOC ratio in O3/catalyst process gave that this process could more proceed the oxidation reaction than O3/H2O2 oxidation process. Therefore, it was considered that O3/catalyst advanced oxidation process could be used as a effective oxidation process for removing non-degradable toxic organic materials.