Formaldehyde removal mechanisms in a biotrickling filter reactor

Formaldehyde (FA) is one of toxic, mutagen, suspected carcinogen and teratogen pollutants presented in contaminated air and might be commonly released from a wide range of the industrial activities. Even though many studies have been made to remove FA from synthetic contaminated air stream (SCAS) using a biotrickling filter reactor (BTFR), the mechanisms of FA removal by a BTFR treatment process must to be verified. The aim of this study was to perform the laboratory-scale BTFR experiments to remove FA from the SCAS during a period of 21 days after passing an adaptation phase of 90 days. The mechanisms of FA removal from SCAS in biofilter must pass through two successive stages: (1) the first diffuses FA from gas phase to aqueous phase to form formic acid and methanol and (2) the second guarantees that the predominant microorganisms are able to metabolise the chemicals-derived FA from aqueous phase for growth and maintenance of life. The research findings may lead to better understanding of the BTFR design and operations to reduce air pollutants in order to maintain or improve air quality.