Implementation of Chitosan modified ultrafiltration hollow fiber as proton exchange membrane of ml-scale microbial fuel cells

Abstract

The study investigated the modification of polyethersulfone (PES), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN) hollow fiber membranes using a chitosan solution as the proton exchange membrane for microbial fuel cells (MFCs). Firstly, the performance of the modified PES membrane using 1, 2, and 3% of chitosan in 0.1 M acetic acid coating were inspected. Chitosan coating decreased the internal resistance and enhanced the electricity generation of the MFCs. The maximum power and current densities of 755.202 mW/m2, and 5525.42 mA/m2 were achieved for 3% chitosan-coated PES (PES-3%chi) compared to 629.533 mW/m2 and 3237.79 mA/m2 for pristine PES membrane. Thereafter, application of a 3% chitosan coating over the PAN and PVDF membranes exhibited excessive improvement in the bioelectricity generation and wastewater treatment efficiency of the MFCs. The PAN-3%chi achieved the uppermost power and current densities of 765.147 mW/m2 and 8297.46 mA/m2, which were 1.7 and 2.6 higher than the PAN membrane (450.675 mW/m2 and 3216.56 mA/m2). The electricity generation of the PVDF membrane was enhanced by 5.3 times (337.134 mW/m2 and 2720.16 mA/m2) after the addition of 3% chitosan, likely due to the improvement in hydrophilicity and proton conductivity. The COD removal efficiencies of 42.41, 40.55, and 36.11% were obtained by PAN-3%chi, PES-3%chi, and PVDF-3%chi membranes, respectively, which were 3.53, 4.01, and 5.53 times higher than the values obtained by their pristine unmodified samples.

Keywords

• microbial fuel cell
• chitosan
• hollow fiber membrane
• domestic wastewater
• wastewater treatment