Carbon-modified zeolite derivates based filler in mixed matrix membrane adsorbers (MMMAs) for enhancing urea and creatinine removal from hemodialysis spent dialysate

Conventional dialysate recycling methods struggle to effectively remove creatinine, urea, and other minor contaminants. This study explores mixed matrix membrane adsorbers (MMMAs) as a novel approach to address these challenges. MMMAs, which integrate adsorbents into filtration membranes, function as both filters and impurity scavengers. Zeolite carbon composite (ZCC) and zeolite-templated carbon (ZTC) were incorporated into MMMAs using the non-solvent induced phase separation (NIPS) technique. Characterization by SEM and XRD confirmed the successful synthesis of ZCC and ZTC, retaining the zeolite-Y structure and amorphous nature, with notable differences in particle sizes (680 and 379 nm) and crystallite sizes (0.45 and 0.02 nm). FTIR revealed hydrogen bonding interactions between ZCC and PVP, absent in ZTC. SEM and AFM analyses of the membranes indicated increased hydrophilicity and porosity with ZCC, while ZTC reduced surface roughness. MMMAs significantly outperformed pristine membranes in removing urea and creatinine. The PPK-0.2 membrane achieved superior rejection rates (93.05 % for urea and 98.95 % for creatinine), attributed to microporous entrapment of ZTC and polymer matrix adsorption. In contrast, PPZ-0.2 showed lower rejection rates (84.24 % for urea and 85.79 % for creatinine), relying solely on physical adsorption. These findings highlight MMMAs, especially ZTC-based ones, as promising candidates for enhancing dialysate reuse efficiency.