Effect of experimental parameters on the voltage output of a sediment microbial fuel cell
Author: Ana Iris Correa Muler
Year: 2016
Supervisor: María Sigríður Guðjónsdóttir & Ásdís Helgadóttir
Abstract
Sediment microbial fuel cells or SMFCs, are single-chamber microbial fuel cells, which use organic matter from sediment as an anode. By using sediments, these microbial fuel cells can be deployed in nature where their most common application is remote sensing. Energy is often scarce in remote locations, but these fuel cells can supply electricity using sediments and water found in nearby rivers and lakes. Just as with any type of microbial fuel cell, their voltage output is limited. Hence, in this study, tests were performed to determine parameters and conditions that can increase voltage production of SMFCs. SMFCs were built inside a 1.2 L cylindrical plastic box with two distinct layers, the sediment at the bottom and water at the top. Electrodes, made from carbon brushes, were fixed to both layers and connected by an external resistor. The conditions studied included: the effect of temperature and aeration of the water layer. Higher room temperatures lead to higher voltage production. Likewise, water aeration increased voltage output. To optimize voltage production, it is important to study the environmental conditions before deployment of the fuel cells to ensure optimal temperature and water aeration. Additionally, electrical conductivity (EC) of the soil was measured at the beginning of the experiment to determine if there was a correlation between EC and voltage output. No correlation was observed. A different fuel cell set-up is required to measure EC throughout the whole experiment, instead of only at the beginning, allowing the correlation to voltage to be studied.