Removal of Acetone Vapor from Air Using a Biotrickling Filter Packed with Polymeric Bioballs

Acetone released into the atmosphere can adversely affect human health and the environment. The aim of this work was to evaluate the performance of a laboratory-scale biotrickling filter (BTF) with bioball packing material to remove acetone vapor from contaminated air. The acetone removal efficiency was investigated in two different scenarios: with and without the inoculation of microorganisms. Three strains of bacteria, Pseudomonas putida, Rhodococcus aerolatus, and Aquaspirillum annulus, were used in the BTF. In both cases, the filter units were simultaneously operated for 100 days under three different inlet acetone concentrations (0.18 ± 0.01 g/m3, 0.25 ± 0.01 g/m3, and 0.40 ± 0.02 g/m3) and two different gas flow rates (2.54 and 5.09 m3/h). The results showed that acetone removal was greater in the filter with the inoculated bacteria. In the filter operated without inoculum, the acetone removal efficiency gradually decreased with filtration time from 90.1% to 6.1%. While employing three types of bacteria in the BTF, the efficiency of acetone removal remained relatively stable and varied between 70.2% and 97.6%. The study also revealed that bioballs can be successfully used as a packing material in air biofiltration systems designed for acetone removal from the air.

Co-Treatment with Single and Ternary Mixture Gas of Dimethyl Sulfide, Propanethiol, and Toluene by a Macrokinetic Analysis in a Biotrickling Filter Seeded with Alcaligenes sp. SY1 and Pseudomonas Putida S1

The biotrickling filter (BTF) treatment is an effective way of dealing with air pollution caused by volatile organic compounds (VOCs). However, this approach is typically used for single VOCs treatment but not for the mixtures of VOC and volatile organic sulfur compounds (VOSCs), even if they are often encountered in industrial applications. Therefore, we investigated the performance of BTF for single and ternary mixture gas of dimethyl sulfide (DMS), propanethiol, and toluene, respectively. Results showed that the co-treatment enhanced the removal efficiency of toluene, but not of dimethyl sulfide or propanethiol. Maximum removal rates (rmax) of DMS, propanethiol and toluene were calculated to be 256.41 g·m−3·h−1, 204.08 g·m−3·h−1 and 90.91 g·m−3·h−1, respectively. For a gas mixture of these three constituents, rmax was measured to be 114.94 g·m−3·h−1, 104.17 g·m−3·h−1 and 99.01 g·m−3·h−1, separately. Illumina MiSeq sequencing analysis further indicated that Proteobacteria and Bacteroidetes were the major bacterial groups in BTF packing materials. A shift of bacterial community structure was observed during the biodegradation process.

Gas-to-aqueous Phase Transfer for Three Paint Solvents Injected into an Abiotic, Industrial Biotrickling Filter Measured with a Flame Ionization Detector

This is a knowledge contribution to the unsatisfactory biodegradation problem, when biotrickling filters are purifying mixed paint solvents. A biotrickling filter manufacturer reported low biodegradation rates during the purification of a hydrocarbon pollutant mix from an industrial paint spraying floor. From a gas chromatograph/mass spectrometer analysis both hydrophilic and hydrophobic solvents were found in the polluted air. It is known that biodegradation is retarded, if the pollutant does not transfer from gas to liquid into the biofilm and it was therefore suspected that hydrophobic pollutants do not sufficiently migrate into the water/biofilm. To test this hypothesis, pure, rather than mixed pollutants, were injected into the abiotic biotrickling filter. When hydrophobic paint solvent (xylene) was sprayed into the biotrickling filter, the solvent load at the outlet of the filter was almost as high as at the inlet. But when pure, hydrophilic paint solvent (PGME) was sprayed into the abiotic biotrickling filter, the solvent load measured at the outlet of the filter was zero, indicating complete dissolution into the circulation water. Carbon/solvent loads at the filter outlet and inlet were measured with a portable flame ionization detector instrument. The experiment confirms that the hydrophobic solvent does not migrate into the liquid phase. This poor mass transfer of hydrophobic solvents is likely to be the reason for the low biodegradation rate. The result is highly relevant to the paint spraying industry and manufacturers of exhaust gas treatment equipment alike, who spend millions in non-sustainable incineration of exhaust gases.

Supplemental figure for "Odorous Compound Removal Performance and Water Properties of a Biotrickling Filter Installed in a Piggery"

This is a supplemental figure 1 for the manuscript entitled "Odorous Compound Removal Performance and Water Properties of a Biotrickling Filter Installed in a Piggery." This figure S1 shows trends in elimination capacity.

Supplemental figure for "Odorous Compound Removal Performance and Water Properties of a Biotrickling Filter Installed in a Piggery"

This is a supplemental figure 1 for the manuscript entitled "Odorous Compound Removal Performance and Water Properties of a Biotrickling Filter Installed in a Piggery." This figure S1 shows trends in elimination capacity.