Details

Autor(en) / Beteiligte

• Mathon, B.
• Coquery, M.
• Liu, Z.
• Penru, Y.
• Guillon, A.
• Esperanza, M.
• Miège, C.
• Choubert, J.-M.

Titel

Ozonation of 47 organic micropollutants in secondary treated municipal effluents: Direct and indirect kinetic reaction rates and modelling

Ist Teil von

• Chemosphere (Oxford), 2021-01, Vol.262, p.127969-127969, Article 127969

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2021

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Micropollutants like pharmaceuticals, hormones and pesticides are still found in treated municipal wastewater. An effective way to degrade micropollutants is to use oxidants such as ozone or hydroxyl radicals. We designed an innovative experimental protocol combining batch experiments and a study of a full-scale WWTP to understand and predict the removal via ozonation of typical micropollutants present in secondary treated effluents. First, the direct and indirect ozonation of 47 organic micropollutants was scrutinized, then a model was developed and calibrated to simulate the ozone transfers and the oxidation of the selected micropollutants. The kinetic rate constants between micropollutants and ozone or hydroxyl radicals (OH●) were determined for 47 micropollutants found in secondary treated effluent. We classified the micropollutants into low- (kO3 between 1.50 and 4.47 × 102 L mol−1. s−1), medium- (kO3 between 1.31 × 103 and 4.92 × 103 L mol−1. s−1) and high-oxidizable groups (kO3 between 9.44 × 104 and 8.18 × 106 L mol−1. s−1) according to their reactivity with ozone, and identified the major degradation pathways for all 47 micropollutants. Micropolluants of the low- and medium-oxidizable groups were largely eliminated by the indirect pathway, at 96% and 84% on average, respectively. In contrast, micropollutants of high-oxidizable group were largely eliminated by the direct pathway, at 98% on average. The model successfully simulated the direct and indirect ozonation of the 47 micropollutants in batch experiments and confirmed the predominant pathways for each group. Finally, the model was applied to the full-scale ozonation process operated at an ozone dose ranging from 0.5 to 1.6 gO3. gDOC−1. The model was found to reliably simulate the ozonation-process removal efficiencies for 4 micropollutants (imidacloprid, fenofibric acid, metronidazole and ketoprofen). [Display omitted] •Batch and WWTP full-scale experiments results were combined to calibrate a new model.•Direct and indirect kinetic rate constants were determined for 47 micropollutants.•Contribution of direct or indirect pathways was determined for each micropollutant.•The proportion of micropollutants consumed by O3 and OH.● radical were determined•The kinetic competition between micropollutants, Br−, NO2− and DOM was integrated.