On-site evaluation of the removal of 100 micro-pollutants through advanced and conventional treatments for re-use applications
Evaluation in-situ de l'élimination d'une centaine de micropolluants par les traitements tertiaires conventionnels et avancés pour la réutilisation des eaux
Résumé
The next challenge of wastewater treatment is to reliably remove micro-pollutants at the microgram per litre range in order to meet reuse applications and contribute to reach the good status of the water bodies. A hundred of priority and relevant emerging substances were measured to evaluate at full-scale the removal efficiencies of 7 advanced treatment lines (1 membrane bioreactor process and 6 tertiary treatment lines) that were designed for reuse applications. To reliably compare the processes, specific procedures for micro-pollutants were applied for sampling, analysis and calculation of removal efficiencies. The membrane bioreactor process allowed to upgrade the removal efficiencies of about 20% of the substances measured, especially those that were partially degraded during conventional processes. Conventional tertiary processes like high rate clarification, sand filtration and polishing pond achieved significant removal for some micro-pollutants, especially for adsorbable substances. Advanced tertiary processes, like ozonation, activated carbon and reverse osmosis were all very efficient to complete the removal of polar pesticides and pharmaceuticals; metals and less polar substances were better retained by reverse osmosis.