Abstract
In this research, the effects of co-existing substances on the decomposition of micropollutants (i.e., 1,2,4-trichlorobenzene (TCB), 1,4-dioxane, and 17β-estradiol) during ozone/hydrogen peroxide (O3/H2O2) process were investigated.
The reaction time for the decomposition of TCB during ozonation increased with the increase of bicarbonate ion, hydroxyl radical (HO·) scavenger, by several ten minutes of magnitude. In the case of O3/H2O2 process, however, the effect of bicarbonate ion on the reaction time of TCB decomposition was a little, therefore, it was less than forty seconds. The effect of H2O2 dose on the removal efficiency of TCB for applied ozone dose was greatly observed in the presence of bicarbonate ion. On the other hand, the effect of it was not observed in the presence of humic acid. The effects of humic acid on the ratio of the applied ozone dose per the amount of target compound decomposed (ΔO3·ΔTarget-1) were dependent upon the reactivities of target compounds with ozone, that is, highly reactive target for ozone was less affected by humic acid. Also, it was found that the effects of highly reactive compounds for HO· (i.e., humic acid, fulvic acid, and glucose) on the decomposition of TCB were higher than those of less reactive compounds for HO· (i.e., acetate and oxalate ions) when total organic carbon of co-existing substances were identical value.
