Process control of air stream deodorization from vapors of VOCs using a gas sensor matrix conducted in the biotrickling filter (BTF)

Abstract

This article presents the validity, advisability and purposefulness of using a gas sensor matrix to monitor air deodorization processes carried out in a peat-perlite-polyurethane foam-packed biotrickling filter. The aim of the conducted research was to control the effectiveness of air stream purification from vapors of hydrophobic compounds, i.e., n-hexane and cyclohexane. The effectiveness of hydrophobic n-hexane and cyclohexane removal from air was evaluated using gas chromatography as the reference method and a custom-built gas sensor matrix consisting of seven commercially available sensors. The influence of inlet loading (IL) of n-hexane and cyclohexane on the biotrickling filtration performance was investigated. The prepared sensor matrix was calibrated with use of two statistical techniques: Multiple Linear Regression (MLR) and Principal Component Regression (PCR). The developed mathematical models allowed us to correlate the multidimensional signal from the sensor array with the concentration of the removed substances. The results based on gas chromatography analyses indicated that the elimination efficiencies of n-hexane and cyclohexane reached about 40 and 30 g m-3 h-1, respectively. The results obtained using a gas sensor matrix revealed that it was possible not only to determine concentration reliably of investigated hydrophobic volatile organic compounds in the gas samples, but also to obtain results of a similar high level of quality as the chromatographic ones. A gas-sensor matrix proposed in this work can be used for on-line real-time monitoring of biofiltration process performance of air polluted with n-hexane and cyclohexane.