Bioelectricity generation in continuously-fed microbial fuel cell: Effects of anode electrode material and hydraulic retention time

Treatment of phenanthrene and benzene using microbial fuel cells operated continuously for possible in situ and ex situ applications

“…The reactor system was capable of sustaining the high removal rates irrespective of the HRT or pollutant loading rates throughout the long-term operation (more than 100 days); hence indicating the robustness of the reactor system. These observations are consistent with results reported previously for petroleum hydrocarbons or organic pollutant removal at different HRTs in MFC systems (Zhang et al, 2012d;Li et al, 2013;Feng et al, 2014;Akman et al, 2013;Kuscu and Sponza, 2009). The MFC system was operated at ambient temperature and temperature fluctuations had little or no apparent effect on petroleum hydrocarbon removal efficiency throughout the period of continuous MFC operation, even during winter period.…”

“…As the ambient temperature increases, due to change of seasons and microbial adaptation, a steady recovery in power outputs was observed which corresponded with a slight increase in COD removal efficiency (Li et al, 2013;Fernando et al, 2014). These observations corroborated well with the results of numerous other studies that reported increase in COD removal efficiencies at higher HRT regimes (Kuscu and Sponza, 2009;Akman et al, 2013;Li et al, 2013) and this can be attributed to the decrease in organic loading rate (OLR) with increasing HRT. This suggests the potential practical deployments of this tubular MFC reactor system for degradation of petroleum hydrocarbons coupled with concomitant bioelectricity production in sub-surface environments where conventional technologies such as permeable reactive barrier (PRB) and in situ chemical oxidation (ISCO) technologies are proven ineffective and unsustainable (in terms of remediation costs and strategy).…”

“…It is likely possible that the biofilms formed on the anode adapted itself to this harsh condition by allowing the microbial cells at the outer surface to switch off or become dormant (in order to preserve itself) while protecting the microbial colony present within the inner part of the biofilm (Juana et al, 1998;Fernando et al, 2014;Akman et al, 2013). This speculation was further supported by fast recovery in overall MFC performance as the MFC was switched to copiotrophic conditions.…”

“…There are several studies in which the effect of HRTs on degradation/COD removal efficiency and power density have been studied (Zhang et al, 2012;Jayashree et al, 2014;Akman et al, 2013;Li et al, 2013). Li et al (2013) investigated the effect of HRTs and non-precious metallic catalyst on MFC performance using MFC fed with animal carcass wastewater.…”

Removal of COD by Two-Chamber Microbial Fuel Cells

“…comparable performance was achieved in our MFC system. Our next purpose is to study the MFC for longer term operation, even in continuous mode of operation, so that we can insert the MFC into the processing scheme of the sugar beet factory [28].…”