| Title |
A Study on Ozonation of 4-nonylphenol |
| DOI |
https://doi.org/10.15681/KSWE.2017.33.6.736 |
| Keywords |
Activation energy; Advanced oxidation process; Ozonation; 4-nonylphenol |
| Abstract |
In this study, 4-nonylphenol (4-NP), an endocrine disrupting chemical, was removed by ozone treatment processes under the various experimental conditions including UV irradiation, TiO2 addition. The ozone flow rate and concentration were maintained at 1.0 L·min-1 and 70±5 mg·L-1. The pH, COD and TOC of the samples were obtained every 10 minutes for 60 minutes in laboratory scale batch reactor. We found that the combination of UV irradiation and TiO2 addition for ozonation improves the removal efficiency of COD and TOC in 4-NP aqueous solution. In case of the O3/UV/TiO2 system, COD and TOC were greatly reduced to 85.3~94.0% and 89.2~97.2%, respectively. 4-NP degradation rate constants, kCOD and kTOC, were calculated based on the COD and TOC values. Significantly, kCOD and kTOC were improved in the O3/UV/TiO2 treatment process compared with single O3 process, because the oxidation and the mineralization of 4-NP were increased by generating of the hydroxyl radical. The kCOD and kTOC were obtained to be 5.81×10-4~10.8×10-4 sec-1 and 11.9×10-4~19.4×10-4 sec-1 in the O3/UV/TiO2 process. Activation energy (Ea) of ozone oxidation reaction based on kCOD and kTOC were in order of O3/UV/TiO2 < O3/UV < O3/TiO2 < O3 process. It was confirmed that the addition of TiO2 and UV irradiation to the ozone oxidation reaction significantly reduced the Ea value and the degradation of 4-NP. |