Removal of heavy metals from mine tailings by in-situ bioleaching coupled to electrokinetics.

This work utilizes a combined biological-electrochemical technique for the in-situ removal of metals from polluted mine tailings. As the main novelty point it is proposed to use electrokinetics (EK) for the in-situ activation of a bioleaching mechanism into the tailings, in order to promote biological dissolution of metal sulphides (Step 1), and for the subsequent removal of leached metals by EK transport out of the tailings (Step 2). Mine tailings were collected from an abandoned Pb/Zn mine located in central-southern Spain.

Analysis of a photobioreactor scaling up for tertiary wastewater treatment: denitrification, phosphorus removal, and microalgae production.

The present work studies the removal of nutrients (nitrate and phosphate) from a synthetic wastewater simulating a secondary treatment effluent using the microalgae Chlorella vulgaris in autotrophic photobioreactors, together with an analysis of the critical points affecting the scaling-up process from laboratory to pilot scale. Laboratory experiments were done in open agitated 1-L photobioreactors under batch operation mode, while pilot-scale experiments were done using a 150-L closed tubular photobioreactor under continuous operation mode. In both scales, nitrate was the limiting substrate and the effect of its concentration on microalgae performance was studied.