Bacteria-mediated Enhanced Natural Attenuation of hexavalent chromium pollution in groundwater

Marina Tumolo 
CNR-IBBR - Italy

October 23, 2024 (11:30-12:30)
Webinar Link: https://teams.microsoft.com/l/meetup-join/19:meeting_ODdhNDIxNzYtYjMzMy00ODI3LTkwNjgtY2IwNGE0NjAxZDY3@thread.v2/0?context={"Tid":"34c64e9f-d27f-4edd-a1f0-1397f0c84f94","Oid":"23377569-3574-440c-bf30-5831d9cc784b"}

Abstract: Hexavalent chromium, Cr(VI), is currently classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen for humans. Its detection in groundwater at concentrations above the legal limit represents a widespread environmental issue, closely related to inadequate industrial waste and wastewater management. The remediation of Cr(VI) pollution is generally based on its reduction to the less toxic and less mobile trivalent state. Among the possible approaches, bioremediation mediated by native bacterial consortia offers several advantages in terms of economic and environmental sustainability, particularly in cases involving large volumes of water to be treated. However, most bacteria living in groundwater are heterotrophic, and in oligotrophic environments, such as aquifers, they require additional nutrients from external sources. Therefore, a key factor for a successful enhanced natural attenuation process is selecting the most suitable amendment, which can support both bacterial growth and reduction processes. To this end, two microcosm-scale experiments were conducted using lactate, yeast extract, and polyhydroxybutyrate as additional carbon sources and electron donors. The results showed the effectiveness of the native micro-organisms, when properly stimulated, in promoting Cr(VI) removal from water, with the rate depending on the type of amendment provided. A metabarcoding approach also revealed that the turnover of the enriched bacterial taxa putatively involved in bioremediation is amendment-specific

Author's Info: https://www.ibbr.cnr.it/ibbr/info/people/marina-tumolo