title: Combined biological and physicochemical waste-gas cleaning techniques.
abstract: This review presents a general overview of physical, chemical and biological waste-gas treatment techniques such as adsorption, absorption, oxidation and biodegradation, focusing more extensively on combined processes. It is widely recognized that biological waste-gas treatment devices such as biofilters and biotrickling filters can show high performance, often reaching removal efficiencies above 90 % for pollutant concentrations below 5 g/m(3). However, for concentrations exceeding this limit and under transient shock-load conditions that are frequently encountered in industrial situations, a physicochemical gas cleaning process can sometimes be advantageously combined with a biological one. Besides improving the overall treatment efficiency, the non-biological, first-stage process could also serve as a load equalization system by reducing the pollutant load during periodic shock-loads, to levels that can easily be handled in the second-stage bioreactor. This article reviews the operational advantages of integrating different non-biological and biological processes, i.e., adsorption pre-treatment+bioreactor, bioreactor+adsorption post-treatment, absorption pre-treatment+bioreactor, UV pre-treatment+bioreactor, and bioreactor/bioreactor combinations, for waste-gas treatment, where different gas-phase pollutants have been tested.
authors.affiliation: Chemical Engineering Laboratory, Faculty of Sciences, University of La Coruña, La Coruña, Spain.
authors.forename: Eldon R
authors.initials: ER
authors.lastname: Rene
authors.forename: María C
authors.initials: MC
authors.lastname: Veiga
authors.forename: Christian
authors.initials: C
authors.lastname: Kennes
mesh_terms: D000393:Air Pollutants / Q000737:chemistry* / Q000378:metabolism*; D000397:Air Pollution / Q000517:prevention & control*; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D005374:Filtration / Q000145:classification / Q000295:instrumentation / Q000379:methods*; D005658:Fungi / Q000378:metabolism; D005740:Gases / Q000737:chemistry* / Q000378:metabolism*; D007220:Industrial Waste / Q000517:prevention & control
chemical_list: D000393:Air Pollutants; D005740:Gases; D007220:Industrial Waste