Bioremediation and Electricity Generation by Using Open and Closed Sediment Microbial Fuel Cells

Abstract

The industrial contamination of marine sediments with mercury, silver, and zinc in Penang, Malaysia was studied with bio-remediation coupled with power generation using membrane less open (aerated) and closed (non-aerated) sediment microbial fuel cells (SMFCs). The prototype for this SMFC is very similar to a natural aquatic environment because it is not stimulated externally and an oxygen sparger is inserted in the cathode chamber to create the aerobic environment in the open SMFC and no oxygen supplied in the closed SMFC. The open and closed SMFCs were showed the maximum voltage generation 300.5 mV (77.75 mW/m2) and 202.7 mV (45.04 (mW/m2), respectively. The cyclic voltammetry showed the oxidation peak in open SMFCs at +1.9 μA and reduction peak at -0.3 μA but in closed SMFCs oxidation and reduction peaks were noted at +1.5 μA and -1.0 μA, respectively. The overall impedance (anode, cathode and solution) of closed SMFCs was higher than open SMFCs. The charge transfer impedance showed that the rates of substrate oxidation and reduction were very low in the closed SMFCs than open SMFCs. The Nyquist arc indicated that O2 act as electron acceptor in the open SMFCs and CO2 in the closed SMFCs. The highest remediation efficiency of toxic metals [Hg (II) ions, Zn (II) ions, and Ag (I) ions] in the open SMFCs were 95.03%, 86.69%, and 83.65% in closed SMFCs were 69.53%, 66.57%, and 65.33%, respectively, observed during 60–80 days. The scanning electron microscope and 16S rRNA analysis showed diverse exoelectrogenic community in the open SMFCs and closed SMFCs. The results demonstrated that open SMFCs could be employed for the power generation and bioremediation of pollutants.

Essential factors that affect bioelectricity generation by Rhodopseudomonas palustris strain PS3 in paddy soil microbial fuel cells

“…We compared the performance of this soil‐based MFC with those reported in the other studies, although it was not able to make equivalent comparisons due to these devices using different components, substrates, operation conditions, or electricigens, etc 11,60‐64 . As shown in Table S2, the average power density (16.5 μW/cm 2 ) of this apparatus was not particularly prominent, however, it presented potential for stable and remarkably durable for long‐term MFC operation (90 days, Figure 5).…”

“…The transferred energy made the "NCTU" LED array light up [Colour figure can be viewed at wileyonlinelibrary.com] devices using different components, substrates, operation conditions, or electricigens, etc. 11,[60][61][62][63][64] As shown in Table S2, the average power density (16.5 μW/cm 2 ) of this apparatus was not particularly prominent, however, it presented potential for stable and remarkably durable for long-term MFC operation (90 days, Figure 5).…”

Insights into Advancements and Electrons Transfer Mechanisms of Electrogens in Benthic Microbial Fuel Cells

“…The drawback of this mechanism is the very poor electron transfer rate, because the active sites of electron transmission are deeply embedded within the proteins [ 45 ]. Recently, many electrochemical bacteria like Shewanella and Geobacter nanowires have been folded for better electrons transmission [ 46 , 47 ]. For effective and fast electron transfer (coulombic efficiency), the nanowires form an electroactive layer instead of a normal single layer.…”

A state of the art review on electron transfer mechanisms, characteristics, applications and recent advancements in microbial fuel cells technology

“…Nernst equation explains an inverse relation between pH and power output in MFC such that a rise in pH will results in a decrease in power output because at higher pH rate of oxygen reduction is reduced. The pH also influences electrically active biofilms on the anode by regulating metabolic pathways of these microbes (64,74). Generally, it is observed that microbial enzymes function best at neutral pH, and deviations from the neutral pH (i.e.…”