G.E.O.S. develops new bioreduction process for sulphate and metal separation - process achieves impressive purification performance

As part of the ERA-MIN 2 project BIOMIMIC, G.E.O.S. developed a new bioreduction process for the treatment of mining water in the "Process engineering" sub-project. The process, which was demonstrated on lab scale, enables the treatment of water containing metals and sulphates by using natural microorganisms in the water in a moving bed reactor.

The new process offers the opportunity to treat the polluted metal-containing mine and industrial waters and thus comply with the permitted discharge limits. Within the project, more than 90 % of the metals (including more than 99 % of the heavy metals) and more than 60 % of the sulphate were removed from the mining water in an old mine near Freiberg during several weeks of operation of the developed reactor. Further advantages of the process are the low technological control requirements, as the process does not require a gas supply. This results in a significantly lower quantity of non-recyclable residues compared to chemical treatment processes. The metal sulphides were precipitated in the reactor by means of sulphate reduction and separated by circulation. The functionality of the process must now be tested on a larger scale for further optimisation.

The BIOMIMIC project was funded by the Federal Ministry of Education and Research. Ten national and international partners took part in the joint project. Now that the project has been completed, the final report of the German partners G.E.O.S. and the Fraunhofer Institute for Systems and Information Research (ISI) has been submitted.