Wastewater treatment, energy recovery and desalination using a forward osmosis membrane in an air-cathode microbial osmotic fuel cell

Effects of current generation and electrolyte pH on reverse salt flux across thin film composite membrane in osmotic microbial fuel cells

“…The final catholyte pH was lower than a theoretical catholyte pH calculated based on the hydroxide ion production (oxygen reduction reaction) from the transferred charge (Fig. 3A) (Werner et al, 2013), indicating that the pH difference could be related to the promoted proton transport. Proton flux could be improved with water flux from the anode to the cathode, which was not considered in the theoretical calculation (Werner et al, 2013).…”

“…Compared to conventional MFCs, OsMFCs can generate more electricity under both a batch mode and a continuous mode using either sodium chloride solution or artificial seawater as the catholyte (Ge et al, 2013;Zhang et al, 2011). Such improved performance of electricity generation was attributed to the lower internal resistance of the OsMFCs than that of the MFCs (Werner et al, 2013). An OsMFC mathematical model was developed, and subsequently predicted a reduction of internal resistance with increasing osmotic pressure gradient and water flux, thereby confirming the importance of membrane resistance (Qin et al, 2015).…”

“…3A) (Werner et al, 2013), indicating that the pH difference could be related to the promoted proton transport. Proton flux could be improved with water flux from the anode to the cathode, which was not considered in the theoretical calculation (Werner et al, 2013). Meanwhile, RSF might stimulate the transport of OH À from the cathode into the anode for charge neutrality, thereby influencing the catholyte pH.…”

“…By inheriting the functions of both MFCs and FO, an OsMFC can simultaneously generate electricity and extract water with the aid of a semipermeable FO membrane that rejects solute ions (Cath et al, 2006;Lutchmiah et al, 2014), separates the anode and cathode, and extracts treated water from the anolyte (feed solution) into the catholyte (draw solution) (Lu et al, 2014b;Werner et al, 2013;Yuan and He, 2015). Like regular MFCs, organic compounds in wastewater are oxidized at the anode of OsMFCs by exoelectrogenic microorganisms and the electrons generated from the anode oxidation reaction are transferred to the cathode through an external circuit where oxygen is reduced to water (oxygen reduction reaction) (Zhang et al, 2011).…”

“…The OsMFC having cellulose triacetate (CTA) embedded support exhibited the higher electricity generation due to the less permeability of oxygen than other membranes (Yang et al, , 2016. Air cathodes have been developed to replace liquid cathodes for improving electricity generation in OsMFCs (Werner et al, 2013). In addition, fouling of FO membrane was found to benefit the current generation of an OsMFC despite the reduction of water flux (Zhu et al, 2016).…”