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Bioaerosols are emitted during the biological treatment of water, soil, and air pollutants. The elimination of these pollutants has become a priority due to their detrimental effects on human health. Advanced oxidation technologies have been used to control bioaerosol emissions specially to improve indoor air quality. This investigation was focused on evaluating the biofiltration of ethyl acetate vapors in terms of removal efficiency and bioaerosol emission. Also, a continuous photocatalytic process to inactivate bioaerosols emitted from the biofilter was assessed as a post-treatment. The photocatalysis was developed with ZnO and TiO2 immobilized onto Poraver glass beads. Flow cytometry (FC) coupled with fluorochromes was used to characterize and quantify bioaerosol emissions in terms of live, dead, and injured cells. Ethyl acetate removal efficiencies were maintained in a steady state with values of 100% under 60-g m−3 h−1 inlet load (IL). Biomass concentration in the biofilter reached values up to 228 mgbiomass gperlite−1 at day 56 of operation, but the spontaneous occurrence of predatory mites diminished biomass concentration by 33%. Bioaerosols emitted during the steady-state operation of the biofilter were composed mainly by bacteria (~ 94%) and in a less extent of fungal spores (0.29–6%). The most efficient photocatalytic system comprised TiO2/Poraver with 78% inactivation of bioaerosols during the first 2 h of the process, whereas the ZnO/Poraver system showed null activity (~ 0%) of inactivation. FC results show that the main mechanism of inactivation of TiO2/Poraver was cell death. [ABSTRACT FROM AUTHOR]

A biotrickling filter was evaluated to treat the air of the interior of a bioprocess research laboratory. Initially, various solid-phase microextraction (SPME) fibers were used to identify and quantify the volatile organic pollutants and hexane, methyl isobutyl ketone, benzene, toluene, and xylene were further selected as indicators due to their prevalence and relative abundance. The system treated organic loading rates between 0.16 mgcarbon m−3 h−1 and close to 30 mgcarbon m−3 h−1 achieving removal efficiencies (RE) over 85% during 136 operational days. Respirometry experiments demonstrated that moderate acidification (below 5.0), due to microbial activity, adversely affected biofilter performance and consequently pH control was necessary to maintain performance. [ABSTRACT FROM AUTHOR]