Post-mortem examination combined with one-time chemical cleaning of fouled flat sheet pvdf-based membrane element used in mbr for tio₂ particle separation

A detailed post-mortem study of fouling formation mechanism and cleaning behavior of fouled membrane elements, used for titanium dioxide (TiO₂) particle separation is of great significance. In this study, a simple but systematic membrane post-mortem analytical procedure was used to investigate foulant composition, fouling formation mechanism and one-time cleaning behavior of fouled flat sheet polyvinylidene fluoride-based membrane elements, used in membrane bioreactor for separating TiO₂ particle. This was achieved by attenuated total reflectance–Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometer, zeta-potential, contact angle, visual inspection, pure water flux, cleaning efficiency and porosity analysis. The morphology, elemental composition and structural result analysis show the scaling elements such as S, Fe, Si, Ti and Al as primary contributors to the overall fouling of the membrane. The zeta potential, contact angle and porosity analysis revealed the electrostatic interactions and adhesion mechanism between the foulant and the membrane surface which were negatively charged and hydrophilic in nature. The chemical cleaning result reveals that 3 M NaClO gave the best cleaning efficiencies having pure water flux of 1,212.7 ± 70.79 and 783.62 ± 26.14 L m^–2 h^–1 and flux recovery of 81% and 51% for cross-flow and dead-end filtration units respectively while the use of H₂ O₂ at higher concentration shows tendencies of refouling the membrane surface.