In the context of Action B1, the BETA Technological Centre is currently performing an experiment to test the efficiency of the Life DEMINE technology in reducing the ecological impact caused by mining effluents on freshwater ecosystems, using the aquatic biofilm as a biological indicator.
In this experiment, we are comparing the response of the aquatic biofilm under the influence of untreated and treated metal mining effluents. To test this, we have been growing biofilm on stones in different aquariums during 20 days under controlled conditions. After this colonization period, treated and untreated metal mining effluents have been added to these aquariums to simulate the discharge of these effluents into the stream. The addition of the mining effluents will last two weeks, and during this period, we will take biofilm samples to analyse its response (e.g. photosynthetic efficiency, biomass and community composition) over time.
The untreated mining effluent consists on water from the original mining effluent in Frongoch Mine (Wales, UK), our demonstration site, with high metal concentration. The treated mining effluents consist on the water resulting from the treatment of this original metal mining effluent by membranes, electrocoagulation (EC), and both methods. This water comes from the experiments that Swansea University is currently performed at bench scale to optimize the LIFE DEMINE technology. The same experiment will be repeated in the next months with the effluent from Menteroda, our other demonstration site, with high concentration of salts. Results from this experiments will help us to elucidate if the application of this new technology, that combines membranes and EC, really supposes a reduction in the impact caused by mining effluents (containing high metal or salt concentration) on freshwater ecosystems, and if the combination of these two processes (membrane and EC) provides benefits compared to their use separately.