4. By-products and waste recovery

Like all transformations, the biological treatment of air pollutants will generate reaction products. We therefore need to take an interest in this final phase of the overall treatment process, and specifically in the fate of these co-products and/or waste products. This approach is in line with the concept of a treatment chain, defined as all the processes leading either to the recovery of the waste, or to its elimination when the waste is qualified as final. According to the 1992 law, waste is said to be final when it is no longer "capable of being treated under current technical and economic conditions". Despite the deadline of July 1 2002, technical landfill sites still accept non-ultimate waste, but other alternatives are now possible, and their choice must be determined according to upstream constraints (quantity, nature, composition of the waste, etc.),...