Simultaneous characterization of porous and non-porous electrodes in microbial electrochemical systems

Abstract

Adequate electrochemical characterization of electrode material/biofilms is crucial for a comprehensive understanding and comparative performance of bioelectrochemical systems (BES). However, their responses are greatly affected by the metabolic activity and growth of these living entities and/or the interference of electrode wiring that can act as an electroactive surface for growth or constitute a source of contamination by corrosion. This restricts the meaningful comparison of the performance of distinct electrode materials in BES. This work describes a methodology for simultaneous electrochemical control and measurement of the microbial response on different electrode materials under the same physicochemical and biological conditions. The method is based on the use of a single channel potentiostat and one counter and reference electrodes to simultaneously polarize several electrode materials in a sole bioelectrochemical cell. Furthermore, various strategies to minimize wiring corrosion are proposed. The proposed methodology, then, will enable a more rigorous characterization of microbial electrochemical responses for comparisons purposes. Experimental Set-up allows to polarize several working electrodes at the same time. Chronoamperometry can be performed simultaneously with a potentiostat. The physicochemical and biological conditions in each working electrode will be exactly the same

Reject brine management: Denitrification and zero liquid discharge (ZLD)—Current status, challenges and future prospects

“…An MFC comprises two cells, one anodic and one cathodic, separated by an ion-exchange membrane. The electrodes of each cell are electrically connected using an external circuit (Prado et al, 2020a). In the anode cell, wastewater exists under anaerobic conditions; the organic matter is oxidized by the action of the electroactive bacteria, and the electrons produced are transferred to the surface of the carbon electrode by direct extracellular electron transfer.…”

Tuning of Electrode Surface for Enhanced Bacterial Adhesion and Reactions: A Review on Recent Approaches

“…Similarly, the use of macroporous 3D electrode architectures can offer a more enhanced performance than 2D electrodes due to the enhanced bacterial adhesion. 267 However, the 3D electrodes with smaller pore sizes can hinder the bacterial penetration and result in a reduced performance. If the diameter of the pores is not suitable for bacterial penetration, the microorganisms can get trapped inside the pores to cause cell death and lead to an overall reduction in the performance of the system.…”

“…The pore diameters of the anode and cathode materials are required to be tuned in the case of MFC and MES systems, respectively, to achieve an enhanced performance. 267 The macroporous 3D carbon-based electrodes are reported to be efficient as anode materials for MFCs. Although metallic 3D architectures are also suitable anode materials, usually carbonaceous material coatings are used on these 3D structures to tune the porosity and bacterial attachment.…”

“…As the microorganism can block the pores and reduce the accessibility into the interior part of the electrode, the performance of the system may get diminished. Similarly, the use of macroporous 3D electrode architectures can offer a more enhanced performance than 2D electrodes due to the enhanced bacterial adhesion . However, the 3D electrodes with smaller pore sizes can hinder the bacterial penetration and result in a reduced performance.…”

“…The pore diameters of the anode and cathode materials are required to be tuned in the case of MFC and MES systems, respectively, to achieve an enhanced performance . The macroporous 3D carbon-based electrodes are reported to be efficient as anode materials for MFCs.…”