Generación de bioelectricidad mediante celdas de combustible microbianas usando aguas residuales de minería aurífera con pleurococcus sp como biocatalizador en la cámara catódica

Abstract

The objective of this study was to generate bioelectricity through microbial fuel cells using wastewater and mine tailings from gold mining with Pleurococcus sp as biocatalyst in the cathode chamber and evaluate the removal of heavy metals such as Mercury, lead, and copper in the anode chamber. The Pleurococcus sp microalga was isolated from the Rodeococha Lagoon of the Llanganates National Park. The experiment was carried out in four single-chamber microbial fuel cells (SMFC) where CM1, CM2, and CM3 had Pleurococcus sp as biocatalyst and CM4 without biocatalyst each with 150 ml of wastewater and 150g of mine tailings. Cellophane paper was used as a proton exchange membrane which separates the anaerobic part from the aerobic part by 1 cm; for the anode and cathode electrodes, carbon fibre was used, and they were subjected to treatments to eliminate impurities and favour the formation of biofilm. Voltage was recorded on an NI 6212 DAQ over 21 days. The results show that the CCM with Pleurococcus sp microalgae is successful in generating bioelectricity compared to the control cell, with a higher voltage production of 31.6% and 21.35%. Through physicochemical analysis, the removal of heavy metals was determined; during the first phase, the CCM1 had a more effective removal of 92% in Mercury and 95% in copper, and the CCM4 94% in Lead. In the second phase, CCM4 removed 97%, 95.3% and 95% of Mercury, Copper, and Lead, respectively. It can be concluded that the cathodes assisted by Pleurococcus sp show more excellent stability and voltage generation in the MCCs. Therefore, it is recommended that for future investigations, consortia of microalgae can be used to obtain better results.