First evidence for applicability of the microbial electrochemical snorkel for metal recovery

Mario Mitov^a,b, Ivo Bardarov^a,b, Elitsa Chorbadzhiyska^a,b, Krassimir L.Kostov^c, Yolina Hubenova^d

Innovative Center for Eco Energy Technologies, South-West University, 66 Ivan Mihajlov Str., 2700 Blagoevgrad, Bulgaria.

Abstract

The proof-of-principle of metal recovery by using the microbial electrochemical snorkel (MES) is provided for the first time. Copper electrodes were short-circuited with the bioanodes of sediment microbial fuel cells (MFC). Two MES setups with and without separation of the compartments by proton exchange membrane (PEM) were developed and their performance was compared with that of an MFC loaded by 510 Ω external resistance. A copper removal of 97.8 ± 4.5% and 98.3 ± 4.8% was achieved for 10 days by MES with PEM and MFC, respectively, while by using MES without PEM a removal of over 95% was obtained for only 2 days. In both operation modes, Cu2O coatings were deposited on the cathodes. The highest cathodic efficiency of 61.7 ± 6.9% was achieved with the MES without PEM, while the highest copper recovery of 42.4 ± 4.9% was obtained with the MES with PEM. The regeneration of copper reached by using MES is over 10% higher than that gained by the MFC. The obtained results show the applicability of MES for water purification from copper without additional energy input.

Keywords: Copper recovery, Microbial electrochemical snorkel, Proof-of-concept, Cathodic efficiency.