超音波 照射에 의한 水중의 Phenol 分解處理 = Treatment of Decomposition of Aqueous Phenol Solution by Ultrasonic Irradiation

다국어 초록 (Multilingual Abstract)

Phenol is the most common and abundant pollutants in the refractory substances and this is difficult to be degradable by conventional methods. Therefore, a considerable interest has been devoted to developing new process where phenol can be easily decomposed.
In this study, the series of ultrasonic irradiation for removal of phenol has been selected as a model reaction in the batch reactor system in order to obtain the basic data investigate the influence of various experimental parameters such as concentration, pH, reaction temperature, acoustic intensity.
The products obtained from the ultrasonic irradiation were analysed by GC/MS and UV spectroscopy.
The formation of H₂O₂, a well-known the strong oxidant was found proportionally to increase with irradiation time.
The intermediates of ultrasonic irradiation of phenol were identified as H₂, CO₂, Catechol, Hydroquinone, and p-Benzoquinone.
As the decomposition of phenol proceeds by the ultrasonic irradiation, the pH of phenol containing aqueous solution increases slowly. The decomposition of phenol was found to be occured fast in the basic medium. In general, the rate of reaction is proportional to the reaction temperature obeying the Arrhenius' law. However, in the ultrasonic irradiation, this suggests as the reaction temperature increase the decomposition rate of the reactant decreases. This result meant that the increase of reaction temperature due to the increase of vapor pressure of water accelerated the decrease of acoustic intensity which was can be proportional to the decomposition rate of these compounds.
It was found that more than 80% of phenol solution was removed within 2 hours in all reaction conditions. The reaction order in the degradation of the phenol confounds was verified as the pseudo-first order.
From the fore-mentioned results, it can be concluded that the refractory organic compounds as phenol could be removed by the ultrasonic irradiation with radicals, such as H· and OH·radical causing the high increase of pressure and temperature. Finally, it appeared that the technology using ultrasonic irradiation can be applied to the treatment of refractory substances which are difficult to be decomposed by the conventional methods.