Biological treatment of waste gases containing volatile organic compounds

Abstract

In recent years, a strong technological base has been developed for air quality zcontrol. The driving force has been public awareness of the need for human health and environmental protection. Consequently, environmental legislation and regulations have been initiated by governments to control air quality. Removing air pollutants, and especially volatile organic compounds (VOC s),from industrial polluted gaseous emissions is achieved by different ways:- Transfer and or concentration of compounds in a liquid phase (condensation, absorption) or onto a solid (adsorption).- Destruction of molecules by thermal oxidation, catalytic treatments, flaring,or degradation of compounds by microorganisms. Among these technologies useful for air treatment, processes involving the biodegradation of pollutants present in the gaseous phase are widely used. They may be applied to both water and air purification (Godish 1997; Liu and Liptak 1997; Heinsohn and Kabel 1999). Thus, these biological systems canre move a large number of molecules, especially volatile organic compounds and odorous molecules. They are generally utilized for the treatment of industrial gaseous emissions. The applications are possible for a concentration of pollutant above 1gm3 to diluted air (some mg or ?gm3). The installation designs cater for an airflow of between 1,000 to 100,000m3 h1, or even more for some systems (Le Cloirec 1998). The principles, processes and modeling of biological systems for air pollution control have been described previously in this book. The objective of this chapter is to present practical approaches to air treatment, especially removal of volatileorganic compounds, by biological methods. Specific points and process examples are developed:- examples and data on the biodegradation of VOC s;- applications of biological processes: general operating conditions and case studies: bio filters, bio trickling filters and bio scrubbers;- treatment of by-products generated by VOC bio treatments. © Springer-Verlag Berlin Heidelberg 2005.