Simultaneous Removal of Hexane and Ethanol from Air in a Biotrickling Filter—Process Performance and Monitoring Using Electronic Nose

Abstract

Biofiltration is a well-accepted method for the removal of malodorous compounds from air streams. Interestingly, the mechanisms underlying this process are not fully understood. The aim of this paper was to investigate the simultaneous removal of hydrophobic hexane with hydrophilic ethanol, resulting in the enhanced removal of hexane in the presence of ethanol. Investigations were performed in a peat-perlite packed biotrickling filter and the process performance was monitored using both gas chromatography and electronic nose techniques. The results indicate that the length as well as the efficiency of biofiltration during the start-up period depend on the feed composition, with higher efficiency obtained when hexane and ethanol were fed together from the process initiation. The experiments in the steady-state period present the biofilter performance when different ratios of hydrophilic to hydrophobic compounds were fed to the biofilter. The obtained results show the synergistic effects of the addition of a hydrophilic compound on the removal efficiency of hydrophobic hexane. The influence of the ratio of hydrophilic to hydrophobic compounds is discussed in terms of enhancing the mass transfer phenomena for hydrophobic volatile organic compounds.

Determination of Odor Air Quality Index (OAQII) Using Gas Sensor Matrix

“…Obviously, in terms of the accuracy of the obtained results, they do not match the chromatographic techniques; however, in cases requiring, for example, quick reaction of industrial facilities, staff sensor arrays are an excellent alternative. Their high application potential has been proven for processes such as monitoring of biofiltration [40][41][42][43][44][45][46], monitoring of methane reforming process [47], monitoring of sanitary conditions [48], monitoring and identification of air pollutants and hazardous substances [49][50][51][52], quality assessment of food products [53][54][55][56][57][58], detection of drugs and explosives [59][60][61], in medicine as a noninvasive diagnostics systems for analysis of breath or urine [62][63][64][65][66], to control indoor air quality [67][68][69] or in the perfume industry to confirm the authenticity of products [55,70].…”

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

“…However, biotrickling filtration of hydrophobic VOCs may be enhanced. This may be achieved, e.g., by modification of liquid phase by adding organic solvents (two-phase bioreactors) or surfactants, use of fungi, dedicated microbial consortia or novel packing materials, introducing gas pre-treatment with, e.g., UV radiation as well as by mixing hydrophobic VOCs with hydrophilic ones (Miller et al 2020, Rybarczyk et al 2021, Cheng et al 2016b, Wu et al 2022. Compared to other deodorization methods, during biofiltration the pollutants are not only removed from the gas, but also inactivated and neutralized during biodegradation by microbes.…”

Archives of Environmental Protection

“…hydrophobic ones, the efficiency of biofiltration depends greatly on the mass transfer rate between the above mentioned phases, and thus the biofiltration efficiency is much lower than for hydrophilic compounds (Cheng et al 2016;Gospodarek et al 2019). Several measures may be applied to improve the biofiltration performance with respect to hydrophobic compounds, including the addition of surfactants, especially biosurfactants, application of selected microbial species, including fungi, reactor modification, selection of proper process conditions as well as co-treatment with hydrophilic compounds (Cheng et al 2020;He et al 2020;Miller et al 2019;Miller et al 2020;Rybarczyk et al 2020Rybarczyk et al , 2019bYang et al 2018Yang et al , 2010.…”