Beta cyclodextrin modified polyvinylidene fluoride adsorptive mixed matrix membranes for removal of Congo red

Abstract

AbstractThis work reports the adsorptive removal of congo red using as‐fabricated polyvinylidene fluoride (PVDF) membranes modified with beta cyclodextrin (β–CD). Diverse techniques were used to characterize the membranes' performance and microstructural and morphological properties. The effect of pH, dye initial concentration, adsorbent dosage, contact time on adsorption efficiency were investigated. Filtration studies were carried out using a dead‐end cell. The results showed that the introduction of β–CD in membrane matrix improved membrane performance, adsorption, and filtration properties. Bulk porosity increased from 61.46% to 87.55% and contact angle decreased from 84.170 to 67.930. Water flux at 1 bar improved from 12.42 to 269.08 L.m−2.hr−1. Maximum adsorption for congo red was obtained at pH 7, with PVDF/β–CD membranes removing 96.15% and pristine PVDF removing 54.27% of congo red. The adsorptive removal of congo red was best described by the pseudo‐second order kinetics and best fitted the Freundlich isotherm model. According to the findings, the adsorption mechanism is credited to electrostatic interactions, hydrogen bonds, and inclusion complexation introduced by β–CD molecules. The dye removal efficiency through filtration was 77.28%. This work indicates that the PVDF/β–CD membranes can be used in the removal of anionic dyes from wastewater through adsorption and filtration techniques. Thus, the distinctiveness of this work is on the mechanistic characteristics of adsorptive mixed matrix PVDF/β–CD membranes on removal of Congo red.