The Biofiltration of Indoor Air:  Air Flux and Temperature Influences the Removal of Toluene, Ethylbenzene, and Xylene

• Published in: Environmental science & technology Vol. 35; no. 1; pp. 240 - 246
• Main Authors: Darlington, Alan B, Dat, James F, Dixon, Michael A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-01-2001
• Subjects: Air Pollutants - isolation & purification; Air Pollution, Indoor - analysis; Air Pollution, Indoor - prevention & control; Applied sciences; Atmospheric pollution; Benzene Derivatives - isolation & purification; Biofiltration; Biological and medical sciences; Biological treatment of gaseous effluents; Bioreactors; Biotechnology; Correlation analysis; Environment and pollution; ethyl benzene; ethylbenzene; Exact sciences and technology; Filtration; Fundamental and applied biological sciences. Psychology; General processes of purification and dust removal; Indoor air quality; Industrial applications and implications. Economical aspects; Pollution; Prevention and purification methods; Temperature; Toluene - isolation & purification; VOCs; Volatile organic compounds; Xylenes; Biodegradation; Microbial activity; Toluene; Optimization; Operating conditions; Biological purification; Phytoremediation; Ethylbenzene; Xylene; Indoor pollution; Aromatic compound; Aquatic plant; Biofilter; Performance; Flue gas purification
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es0010507

An alternative approach to maintaining indoor air quality may be the biofiltration of air circulated within the space. A biofilter with living botanical matter as the packing medium reduced concentrations of toluene, ethylbenzene, and o-xylene concurrently present at parts per billion (volume) in indoor air. The greatest reduction in concentrations per pass was under the slowest influent air flux (0.025 m s-1); however, the maximum amount removed per unit time occurred under the most rapid flux (0.2 m s-1). There was little difference between the different compounds with removal capacities of between 1.3 and 2.4 μmol m-3 biofilter s-1 (between 0.5 and 0.9 g m-3 biofilter h -1) depending on influent flux and temperature. Contrary to biofilters subjected to higher influent concentrations, the optimal temperatures for removal by this biofilter decreased to less than 20 °C at the most rapid flux for all three compounds. Microbial activity was decreased at these cooler temperatures suggesting the biofilter was not microbially limited but rather was limited by the availability of substrate. The cooler temperatures allowed greater partitioning of the VOCs into the water column which had a greater impact on removal than its reduction in microbial activity.