Advancements in Selective Cellulose Acetate/Calcined Eggshell Membranes for Cr(VI) Effluent Treatment and Modeling Approach

Abstract

Mixed matrix membranes (MMMs) are a promising approach for hexavalent chromium Cr(VI) removal from wastewater. In this study, asymmetric membranes were synthesized by incorporating calcined eggshell as a bio-fillers in a polymer matrix. MMMs were synthesized via phase inversion technique at various filler loadings ranging from 5–20% wt.%. Characterizations of synthesised membranes were performed using scanning electron microscopy, thermogravimetric analysis and permeability studies. The results showing the highest flux of 3503 ± 32 L m⁻² h⁻¹ and 60.5 ± 0.8% Cr(VI) rejection were obtained by a membrane with 20 wt.% filler loading. Modeling approach was conducted to compare the experimental data with the pore network and continuum models to predict the transport properties. The pore network model showed the most accurate prediction of membrane transport behavior, with an average absolute relative error of 15.03% compared to other continuum models. The study thus provided the impact of structural influences on pressure distribution within membranes, emphasizing the need of including pore size distribution in the analysis.