| Title |
Removal of Trichloroethylene by O3 / H2O2 Oxidation and Biological Treatment |
| Authors |
신항식 ; 임재림 ; 남세용 ( Hang Sik Shin ; Jae Lim Lim ; Se Young Nam ) |
| Abstract |
The removal efficiency of trichloroethylene(TCE) by O₃/H₂O₂ advanced oxidation process (AOP) and the feasibility of cometabolic degradation of TCE by immobilised microorganisms were investigated in this study for the development of combined process of chemical and biological treatment. In the O₃/H₂O₂ AOP, TCE was removed by pseudo first-order reaction and the removal rate constant was the highest at peroxide-to-ozone dosage ratio(w/w) of about 0.8 and pH 7. However, in the O₃/H₂O₂ AOP, pH 9 was chosen more favored operation condition than other pH for the following biological treatment. The two packed-bed bioreactors filled with Celite and Ceramic bead, respectively, were operated continuously during 186 days. It was observed by scanning electron microscopy (SEM) that bacteria, straight or slightly curved rods type immobilised in the surface pores of the Celite and Ceramic bead. During initial 145 days, which time influent of 4 ppm TCE and 50 ppm phenol was introduced into two bioreactors, immobilised microorganisms degraded effectively TCE utilizing phenol as carbon and energy source. After 145 day operation, influent pretreated by O₃/H₂O₂ AOP at pH 9, containing about 4∼7 ppm TCE, was supplied to the two bioreactors with 65ppm phenol. It was observed that TCE and phenol were degraded simultaneously by cometabolism of microorganisms, but TCE inhibited phenol degradation in a concentration dependent manner. The results showed that by the combined process of O₃/H₂O₂ oxidation and biological treatment, TCE of high concentration could be treated effectively. |