Studies on mixed matrix membranes as efficient materials for dye removal from textile waste-water

초록

The discharge of dye-containing wastewater from textile and manufacturing industries represents a significant environmental challenge due to the persistence and toxicity of dye pollutants. Conventional treatment methods often suffer from limited efficiency, necessitating the development of advanced separation technologies for effective dye removal and protection of freshwater resources. In this work, reduced graphene oxide/polysulfone (rGO/PSU (UF)) mixed matrix membranes were fabricated via the phase inversion technique and evaluated for the rejection of Congo Red (CR) and Eriochrome Black T (EBT) dyes. The incorporation of rGO (0.5 and 1.0 wt.% dispersed within the PSU matrix) significantly improved membrane surface characteristics, pore structure, hydrophilicity, and antifouling behaviour. Small-angle neutron scattering (SANS) was employed to quantitatively investigate membrane pore morphology and correlate it with separation performance. Filtration experiments were conducted on a cross-flow filtration cell at 50 psi transmembrane pressure by using 100 ppm dye solutions (pH 6, temp. 30 degrees C). The PSU membrane incorporated with 1.0 wt.% rGO exhibited the optimum performance, achieving a pure water flux of 162.0 f 2.0 LMH, which was approximately 82% higher than that of the pristine PSU membrane (89.0 f 4.7 LMH), along with high dye rejection efficiencies of 95.6 f 0.4% for Congo Red and 93.1 f 0.6% for Eriochrome Black T. Antifouling performance was also enhanced, with the flux recovery ratio increasing from 22.6% for pristine PSU to 51.3% for the rGO/PSU membrane. The improved separation performance is attributed to the combined effects of enhanced hydrophilicity, optimized pore structure, size exclusion and increased interactions between dye molecules and the rGO/PSU membrane surface. These results demonstrate that rGO/PSU mixed matrix membranes are promising candidates for efficient dye wastewater treatment applications.

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