Biotrickling filtration for control of volatile organic compounds from microelectronics industry

Abstract

This study investigated the transient and steady-state performance of a bench-scale biotrickling filter for the removal of an organic mixture (acetone, toluene, and trichloroethylene) typically emitted by the microelectronics industry. The, microbial consortium consisting of seven bacterial strains that were fully acclimated prior to inoculation onto activated carbon media. Among the seven strains, the Pseudomonas and Sphingomonas strains appeared to be the major groups degrading toluene (> 25 ppmv/h (.) 10(8) cell) and trichloroethylene (>2.3 ppmv/h. 10(8.) cell), while Mycobacteria and Acetobacteriaceae strains were the primary decomposers of acetone (> 90 ppmv/h (.) 10(8) cell). The column performance was evaluated by examining its responses to the fluctuating influent total hydrocarbon concentrations, which varied from 850 to 2,400 ppmv. Excellent steady-state removal efficiencies greater than 95% were consistently observed, and system recovery was typically within two days after a significant increase,in the inlet loading was experienced. The overall mass-transfer rate and the biokinetic constants were determined for each organic component. Mathematical simulations based on these parameters demonstrated that the removal of acetone was kinetically limiting, whereas the removals of toluene and trichloroethylene were. at least partially mass-transfer limiting.