Enhancement of Mud Water Filtration Performance via <scp> CO ₂ </scp> Plasma‐Induced Polar Functionalization of Polysulfone Membranes

ABSTRACT The present study investigates the effect of radiofrequency carbon dioxide plasma exposure on polysulfone membranes to improve surface hydrophilicity and antifouling characteristics for enhanced performance in mud‐water treatment. A comparative study was conducted to analyze control and exposed membranes through contact angle measurements with a goniometer, and surface chemistry characterization via X‐ray photoelectron spectroscopy. Surface morphological changes after plasma exposure were investigated using scanning electron microscopy and atomic force microscopy. Micro‐CT scanning was used to investigate the impact of plasma treatment on the bulk properties of the membrane. A significant increase in surface hydrophilicity of the modified membrane (from 80° to 48.8°), along with a ~22‐fold increase in permeability, was observed. Mud‐water filtration carried out in a batch cell showed a ~12‐fold flux increment for the modified membrane, with complete flux recovery of around 99% ± 1% and 14% ± 5% reduction in the flux decline ratio. The rejection performance remained unaffected after exposure, and the optical microscopic imaging confirmed the absence of mud particles in the permeate samples. Hermia's fouling model equations were fitted to the experimental data to investigate the fouling mechanisms on the membrane surface. Additionally, a transport model for permeability prediction of the modified membrane was validated against experimentally measured permeability.