Biotrickling Filtration of Volatile Organic Compounds in Vented Gases from Surface-Coating Operations

Abstract

The study used a bench-scale biotrickling filter packed with mixed plastic chips with specific surface area of 610±50 m2/m3 to test its performance for the removal of volatile organic compounds (VOCs) vented from paint-spraying operations. A paint containing ethyl acetate, butyl acetate, toluene, and xylenes as main solvents was used. The influent total hydrocarbon (THC) concentrations were in the range of 27–234 parts per million (ppm) (expressed as methane equivalent), and empty bed retention time (EBRTs) for the gas flowing through the empty bed space were 4.8–11.4 s in the experimental period of 125 days. Results show that a maximum THC removal capacity of 86 g as methane/m3 h with an EBRT of 4.8–8.2 s was obtained and the value implies that it is possible to effectively eliminate VOCs with the short EBRT compared with other related studies. Ethyl acetate and butyl acetate were more easily absorbed and removed by microbial films than toluene and xylenes because of the much lower volatility and higher water affinity of the former two compounds.