Roll-to-Roll Processing of Hybrid MOF and Nylon Membranes for High Efficiency Removal of Toxic Gases, Heavy Metals, and Dyes

Abstract

This study demonstrates a process to produce a diverse functional membrane that comprises nylon 6,6 and metal–organic framework (MOF) particles to purify environments of toxic gases, heavy metal ions, and waste dyes. Roll-to-roll hot pressing was used to fabricate a hybrid membrane of nylon 6,6 and adsorptive MOF [zeolitic imidazolate framework-8 (ZIF-8) and FeBTC]. In addition, two- and three-MOF layer membranes were prepared by repeating the hot pressing process, and the type and morphology of the synthesized MOFs were confirmed through scanning electron microscopy and X-ray diffraction. The results show that the larger the number of MOF layers, the greater the removal efficiency for toxic gases. The FeBTC@Nylon 3rd membrane removed 100% of the NH3 gas in 30 min, and the ZIF-8@Nylon 3rd membrane removed 100% of the H2S gas in 60 min. Both types of membrane have excellent adsorption performance for heavy metals and dye-contaminated wastewater, which otherwise harm the biodiversity of water bodies and destroy the food chain over extended periods and cause damage to humans. Kinetic model analysis revealed that the adsorption reaction for heavy metals followed the second-order kinetic model, and chemical adsorption was confirmed. These results highlight the significance of process design in determining an optimum membrane for the removal of a variety of toxic materials.

Treated Kaolin Clay Incorporated with Nickel Nanoparticles for Enhanced Removal of Crystal Violet and Methyl Orange from Textile Wastewater

“…The kinetic study was evaluated by fitting the kinetic data to pseudo-first order, pseudo-second order, Elovich, and intraparticle kinetic model represented in eqs 5, 6, 7, and 8, respectively. 30,31 = q q (1 e )…”

“…The kinetic study was evaluated by fitting the kinetic data to pseudo-first order, pseudo-second order, Elovich, and intraparticle kinetic model represented in eqs , , , and , respectively. , q t = q e false( 1 − e − k 1 t false) q t = k 2 q e 2 t 1 + k 2 q e t q t = 1 β In false( 1 + α β t false) q t = k p t 1 / 2 + C where q t and q e (mg/g) denote the absorbed amount of CV and MO at a specified time and at equilibrium. The kinetic rate constants k 1 (1/min), k 2 (mg/g min), α (mg/g·min), and k p are associated with the pseudo-first order, pseudo-second order, Elovich, and intraparticle adsorption at the initial rate.…”