Optimization of an Innovative Biofiltration System as a VOC Control Technology for Aircraft Painting Facilities

摘要

Each year, painting operations at DoD maintenance facilities emit large quantities of volatile organic compounds (VOCs) into the atmosphere. The goal of this research project was to assess the feasibility of using biofilters to remove VOCs from gas emissions exiting paint spray booths. Several bioreactor designs and operating strategies were investigated and performance of an integrated biofiltration system was evaluated first at the laboratory and then at the pilot scale. Results indicate that numerous bioreactor configurations are capable of achieving paint VOC removal efficiencies in excess of 90%. Regardless of the particular bioreactor configuration investigated or the microbial inocula utilized, aromatic hydrocarbons were consistently found to be the most slowly degraded in the biofilters. Biofllm establishment and nutrient supply rates also strongly influenced the performance of the biofiltration systems. Once a robust bioflim was established in the bioreactors, however, these systems could effectively treat complex VOC mixtures even during intermittent feed conditions expected to occur in full- scale painting operations. A slip-feed system was found to be useful for maintaining microbial activity particularly in the pilot-scale bioreactor treating actual paint emissions on an intermittent schedule. The study results indicate that biofiltration systems are feasible for treating emissions from DoD paint spray booths and can be used to effectively meet a variety of potential treatment goals.