From waste to resource

Brazil

The project leader of research group from Brazil – Prof. Andrea Moura Bernardes.

Prof. Andrea Bernardes is a Full Professor in Post-Graduation Program in Mining, Metallurgical and Materials Engineering (PPGE3M). It`s department of the Fedral Univeristy of Rio Grande do Sul (UFRGS).

The Brazilian research group will focus on the development of electrodialysis processes to improve the recovery of salts from different wastewater. Water desalination by electrodialysis has been applied in many countries. Water reclamation and reuse processes are also nowadays practiced in many countries around the world. Nevertheless, the current reuse represents only a small fraction of the total volume of municipal and industrial wastewater produced and the recovery of salts is still a matter of research. Electrodialysis processes will be applied to the  recovery of salts from industrial wastewater (galvanic and mining effluents), aiming metals recovery, as well as to the recovery of salts from municipal wastewater, mainly to the recovery of phosphates. Current efficiency data and percentage ion extraction will be analyzed to verify the efficiency of the processes. The influence of different cations and anions present in the effluents, as well as the influence of the presence of complexing agents (cyanide, EDTA, tartrate) will be analyzed by techniques such as cyclic voltammetry and chronopotentiometry to verify the competition and transport efficiency of ions through the membrane. Reactive electrodialysis, where the electrode reactions will be used to the reduction or oxidation of pollutants, will also be evaluated. In fact, when electrodialysis is applied to water desalination, the produced concentrate may contain ions, such as nitrate, that could be then treated on a second process step by reactive electrodialysis, being the nitrate reduced to nitrogen on the cathodic compartment of the stack. This approach will be considered different stack configurations. Besides, different electrodialysis membranes and applied current densities should be evaluated to mitigate fouling and scaling in all electrodialysis processes evaluated. All studied processes should generate clean water and a salt concentrated solution, which can be further concentrated by the methods studied by the other teams of the consortium.