Effect of simple interventions on the performance of a miniature MFC fed with fresh urine

Asimina Tremouli,John Greenman,Ioannis Ieropoulos

doi:10.1016/j.ijhydene.2021.07.171

Asimina Tremouli, John Greenman + Show 1 more

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https://doi.org/10.1016/j.ijhydene.2021.07.171

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Abstract

The aim of the present study is to enhance the performance of a microbial fuel cell (MFC) design by making simple interventions. Specifically, terracotta “t” and mullite “m” ceramics are tested as membranes while carbon veil and carbon cloth are used as electrodes. In the case of “m” cylinders different dimensions are examined (m: ID 30 mm x height 11.5 mm; sm: ID 18 mm x height 18 mm). The units operated continuously with urine as the feedstock. The best performing is the sm type (60–100 μW), followed by the t type (40–80 μW) and the m type (20–40 μW). Polarisation experiments indicated that activated carbon on the anode enhances the power output (t: 423 μW, sm: 288 μW). Similarly, the increase of the surface area and the addition of stainless steel mesh on the cathode improves the power performance for the “sm” and the “t” units. Furthermore, it is shown that the design with the smaller internal diameter, performs better and is more stable through time.

Highlights

During the last twenty years, many microbial fuels cell (MFC) systems have been developed at different research laboratories
Two 3D printed acrylo-nitrile butadiene styrene (ABS) lids were used for sealing the tubes and for supporting the inlet and outlet tubes
The results for the m group, revealed that the higher values of maximum power Pmax resulted from the CC anode electrode (94 mW, 77 mW, 8 mW, 8 mW for the 1st, 3rd, 4th and 5th polarisation experiment, respectively) followed by the activated carbon (AC) anode (72 mW, 24 mW, 12 mW, 8 mW and 8 mW for the 1st, 2nd, 3rd, 4th and 5th polarisation experiment, respectively), the CV anode (59 mW, 21 mW, 6 mW, 6 mW for the 1st, 3rd, 4th and 5th polarisation experiment, respectively) and the steel mesh (SS) cathode (19 mW, 51 mW, 12 mW, 12 mW for the 1st, 3rd, 4th and 5th polarisation experiment, respectively) (m3>m2>m1>m4). This behavior was consistent throughout the end of work, for all MFC types

Summary

Introduction

During the last twenty years, many microbial fuels cell (MFC) systems have been developed at different research laboratories. The desired traits of the electrodes are the high effective surface area, the high electrical conductivity, their stability and durability, their biocompatible properties (for biotic electrodes), the low pore clogging as well as their low cost [13]. In this direction, carbon electrodes and metal electrodes have been extensively tested both as anode and cathode electrodes [14e17]. Singh and Verma [22] fabricated nickel (Ni) nanoparticles- (NPs) dispersed web of carbon micro-nanofibers (ACFs/CNFs) and used them as the electrodes in a dual chamber MFC achieving power density 1145 ± 20 mW/m2. The above approaches could replace expensive electrodes used in MFCs

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