Lab-scale experimental strategy for determining micropollutant partition coefficient and biodegradation constants in activated sludge
Méthodologie de détermination du coefficient de partition et des constantes de biodégradation de micropolluants en boues activées
Pomiès, M. ; Choubert, J.M. ; Wisniewski, C. ; Miège, C. ; Budzinski, H. ; Coquery, M.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA LYON UR MALY FRA ; IRSTEA LYON UR MALY FRA ; CIRAD UMR QUALISUD UNIVERSITE MONTPELLIER I MONTPELLIER FRA ; IRSTEA LYON UR MALY FRA ; CNRS UMR 5805 EPOC TALENCE FRA ; IRSTEA LYON UR MALY FRA
Résumé / Abstract
The nitrifying/denitrifying activated sludge process removes several micropollutants from wastewater by sorption onto sludge and/or biodegradation. The objective of this paper is to propose and evaluate a lab-scale experimental strategy for the determination of partition coefficient and biodegradation constant for micropollutant with an objective of modelling their removal. Four pharmaceutical compounds (ibuprofen, atenolol, diclofenac and fluoxetine) covering a wide hydrophobicity range (log Kow from 0.16 to 4.51) were chosen. Dissolved and particulate concentrations were monitored for 4 days, inside two reactors working under aerobic and anoxic conditions, and under different substrate feed conditions (biodegradable carbon and nitrogen). We determined the mechanisms responsible for the removal of the target compounds: (i) ibuprofen was biodegraded, mainly under aerobic conditions by cometabolism with biodegradable carbon, whereas anoxic conditions suppressed biodegradation; (ii) atenolol was biodegraded under both aerobic and anoxic conditions (with a higher biodegradation rate under aerobic conditions), and cometabolism with biodegradable carbon was the main mechanism; (iii) diclofenac and fluoxetine were removed by sorption only. Finally, the abilities of our strategy were evaluated by testing the suitability of the parameters for simulating effluent concentrations and removal efficiency at a full-scale plant.
Environmental Science and Pollution Research, vol. 22, num. 6, p. 4383 - 4395