Surface modification of polymeric media coated with conductive polyaniline to enhance methane production for anaerobic low-strength wastewater treatment

Highlights: • Conductive media was synthesized by coating PANI on PET bead and PVDF pellet. • Surface polymerization and dipping method were compared by microscopic analysis. • Spectrum peaks confirmed successful PANI coating on PET bead and PVDF pellet. • PVDF pellet with higher surface area showed more deposit of PANI than PET bead. • PANI-PVDF pellet produced methane production rate at 22 % faster than uncoated one. In this study, polyethylene terephthalate (PET) beads and polyvinylidene fluoride (PVDF) pellets were coated with polyaniline (PANI) via the dipping and surface polymerization methods. Both materials were evaluated to determine whether the conductive polymer could improve methane production rates under anaerobic conditions. With a higher surface area, PVDF pellets facilitated more PANI deposition than PET beads, and this was more pronounced using surface polymerization than with the dipping method. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) peaks demonstrated the successful coating of both PET beads and PVDF pellets with PANI. However, at a PANI concentration of 1 M, there was no significant difference in the spectrum peak obtained from both surface polymerization and dipping. The surface impedances of PET beads and PVDF pellets decreased after being coated with PANI, confirming increased surface conductivity. The methane production rate of PET beads coated with PANI was 9% higher than that of uncoated beads. Similarly, the methane production rate of PANI-coated PVDF pellets was 25% higher than that without pellets in the presence of seed biomass only.