Development of Parallel Trickling Biofilter for the Treatment of Gas-phase Trichloroethylene

A parallel TBF system that is consisted of two TBFs was developed f ‘ or the long-term treatment of gas-phase trichloroethylene (TCE). Each TBF was operated for TCE degradation or reactivation in a parallel mode, and the effect of switching time and operation variables between the two reactors was investigated. Within 12 hr after switching from TCE degradation to reactivation mode, the MO activity increased up to the initial level. More than 50 % of TCE was degraded for feed concentrations ranging from 5 to 17 ppmv, and completely 100 % removed at concentration of less than 5 ppmv, while TCE removal decreased severely over 28 ppmv. In various empty bed retention times (EBRTs), ranging 상 om 5.2 to 10.7 min, the optimal EBRT was 10.7 min that TCE conversion achieved more than 50 %. For the inlet loading below 23.4 mg TCE/L/day, TCE was entirely removed. The maximal TCE elimination capacity in this system was about 66.63 mg TCE/L/day. During the continuous treatment of TCE over 3 months, TCE removal efficiency was maintained at the range of about 50 %. In these results, the parallel TBF system can be available for the continuously TCE biodegrading operation.