TREATMENT OF NITROGEN-OXIDES ON A PERCOLATING BIOFILTER AFTER PRECONCENTRATION ON ACTIVATED CARBON

The purpose of this study was to examine possible treatments of combus tion gas emissions, especially nitrogen monoxide, discharged by instal lations or equipment such as road tunnels, with very small amounts of pollutants (in the order of 10 mg m(-3)) and very large volumic flux ( many thousands of m(3) h(-1)). After a feasibility study, we have show n the necessity to proceed with a preliminary step of pollutant concen tration or oxidation in order to obtain an effective purification. We have developed two ways for treatment of nitrogen oxides (NOx), consis ting of coupling physical, chemical and/or biological processes. In th is paper,we present and discuss results regarding the second case, whi ch consists of a nitrogen monoxide (NO) pre-concentration onto activat ed carbon (Pica NC. 60), followed by a thermal desorption of NOx and a biological treatment of the desorbed gas. (C) 1998 Elsevier Science L td. All rights reserved.