On-site Treatment of Arsenic-rich Acid Mine Drainage by Sulfate-Reducing Bioreactor
| Autor: | Diaz-Vanegas, Camila, Battaglia-Brunet, Fabienne, Joulian, Catherine, Barry, O., Djibrine, Adam, Malcles, A., Liming, Lin, Desoeuvre, Angelique, Casiot, Corinne, Hery, Marina, Jacob, Jérôme |
|---|---|
| Přispěvatelé: | Hydrosciences Montpellier (HSM), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Laboratoire de Génie de l'Environnement Industriel et des Risques Industriels et Naturels (LGEI), IMT - MINES ALES (IMT - MINES ALES), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | EcotoxicoMic 2020-Second International Conference on Microbial Ecotoxicology EcotoxicoMic 2020-Second International Conference on Microbial Ecotoxicology, Oct 2020, Montpellier, France |
| ISSN: | 1500-3000 |
| Popis: | International audience; Acid mine drainage (AMD) is one the main problems of the inadequate management of mining wastes. Often those acid effluents induce the release of metals and metalloids such as iron (Fe), arsenic (As) and zinc (Zn) into aquatic ecosystems resulting in a threat for the environmental and human health. Bioremediation has been identified as a potential sustainable strategy to treat AMD and remove toxic elements from water. Particularly, bioremediation technologies using sulfate-reducing bacteria (SRB) present advantages such as low quantity of sludge production, simultaneous precipitation of metals/metalloids and increase of effluent pH. Moreover, it also contributes to decreasing sulfate discharge. However, optimizations are required under specific conditions, for example to avoid inhibition of SRB activity by strong acidity and elevated ferric iron concentration. To contribute to fill those gaps, the goal of the present study is to evaluate the functioning of a sulfate-reducing bioreactor working on-site. This bioreactor was designed to remove As and Zn from the As-rich AMD of the Reigous creek at the ancient Pb-Zn Carnoulès mine. The SRB bioreactor is fed directly with Reigious creek water under up-flow conditions, this influent being characterized by pH 2.7-3.5, 500-1000 mg/L of Fe, 50-100 mg/L of As, 10-20 mg/L of Zn and 1500-3000 mg/L of SO4. The bioreactor has a total volume of 25 L and a working volume of 14 L. The inoculum, consuming glycerol as electron donor, originally inoculated by a SRB-containing consortium enriched from the sediments of the Reigous creek. The bioreactor was scale-up from 300 mL to 25 L. This consortium is already adapted to the extreme conditions of the AMD, and its capacity to reduce sulfate at pH of 3 to 4 has been demonstrated. The SRB bioreactor has been monitored during one year since its installation in July 2020. Under steady state conditions it removed nearly entirely As and Zn with a residence time of 4 days, and increased the pH from 3.7 to 6. Performance also remained stable despite variations in water chemistry across seasons. The characterization of the bacterial community performing reduction of SO4 and precipitation of metals (Zn, Fe) and As in this bioreactor is under progress. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|