Stéphanie Jacquet (MIO-CEM) is taking part, on board the Janus II (SAAS - Ship As A Service / COMEX marine) with colleagues from CREOCEAN and GET Toulouse, in the ALT4 mission to monitor the discharge of clarified effluent from the Gardanne alumina production plant (Bayer bauxite extraction process). Since 2016, the plant's waste (sludge) has been filtered in presses (and stored again on land) and, since 2019, the clarified residual effluent has been treated in a CO2 treatment plant before being sent out to sea.
Water, hydrotalcite and sediment samples were taken at the head of the Cassidaigne canyon at the effluent discharge point, using Achille and Apache ROVs and sampling bottles.
The programme includes chemical and mineralogical analyses of all the samples.
Also on board are Julien and Katia, two film-makers working on a documentary on the major theme of red mud as part of a project I am carrying out in collaboration with Y. Noak and J. Rouchier.