Reducing indoor air pollutants through biotechnology

Abstract

Indoor environmental quality is a growing concern, as populations become more urbanised and people spend a greater proportion of their lives indoors. Volatile organic compounds outgassing from synthetic materials and carbon dioxide from human respiration have been major indoor air quality concerns. The growing use of energy-efficient recirculating ventilation solutions has led to greater accumulation of these pollutants indoors. A range of physiochemical methods have been developed to remove contaminants from indoor air, but all methods have high maintenance costs and none reduce CO2, which some biological systems can achieve effectively with the additional benefit of the self-sustaining capacity of biological material. Bacteria are the major organisms involved in bioremediation of VOCs, although green plants may help sustain the bacterial community and add the capacity for CO2 reduction to a system. The main problems faced by indoor air bioremediation systems is the extremely low concentrations of VOCs present indoors and the possibility of microbial release. Simple, passive biofiltration with potted green plants may be the simplest and most effective system for indoor air cleaning, but further research into substrate types, ventilation, and the microbiology of biodegradation processes is required to reveal their ultimate potential. Purely microbial systems have potential for the bioamelioration of high concentrations of toxic gases, but not without significant maintenance costs. Despite many years of study and substantial market demand, a proven formula for indoor air bioremediation for all applications is yet to be developed.