Transforming an end-of-life reverse osmosis membrane in a cationic exchange membrane and its application in a fungal microbial fuel cell

This article describes for the first time the elaboration of a cationic exchange membrane (CEM) from an end-of-life reverse
osmosis (RO) membrane. The cationic exchange membrane has been prepared in two successive steps: (i) chlorine attack and (ii)
filtration/adsorption of a polystyrene sulfonic acid (PSS) electrolyte solution. Physicochemical characterizations have been
undertaken including (Na
+
) transference number (t(Na
+
)), diffusion flux measurements (Js), and cationic exchange capacity
(CEC) determinations, as the properties encountered for a classical cationic exchange membrane. The hydraulic permeability
(Lp) was also determined to characterize the molecular weight cut-off. This novel membrane denoted as ANIMAX has also been
characterized by ATR-FTIR and SEM/AFM tools. We have utilized an old brackish water membrane denoted BW30 (stocked in
bisulfite 1% for 10 years) to develop a new sulfonated UF membrane with a molecular cut-off of 55 kDa. We have observed that
the roughness was divided by 2 (295 to 144nm) showing a lower propensity to fouling/biofouling of the novel membrane
elaborated. As for the application, the newly synthesized membrane has been tested during 4 days of experiments in a fungal
microbial fuel cell laboratory set-up vs Nafion© 117 the usual cationic membrane in MFC technology. We observed a lower
external resistance with a value of 8 kOhm vs 37 kOhm for ANIMAX vs Nafion®117, respectively.