Efficient removal of anionic, cationic textile dyes and salt mixture using a novel CS/MIL-100 (Fe) based nanofiltration membrane

• Published in: Chemosphere (Oxford) 2021-12, Vol.284, p.131244, Article 131244
• Main Authors: Gnanasekaran, Gnanaselvan, Sudhakaran, M.S.P., Kulmatova, Dilafruz, Han, Jeongho, Arthanareeswaran, G., Jwa, Eunjin, Mok, Young Sun
• Format: Article
• Language: English
• Subjects: Biopolymer; Chitosan; Coloring Agents; Hazardous waste; Membranes, Artificial; MOF membrane; Nanofiltration; Sodium Chloride; Spectroscopy, Fourier Transform Infrared; Textile wastewater; Textiles; Water Purification
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.131244

The purification of hazardous textile dyeing wastewater has exhibited many challenges because it consists of a complex mixture, including dyestuff, additives, and salts. It is necessary to fabricate membranes with enhanced permeability, fouling resistance, stability, and superior dyes and salts removal from wastewater. Incorporating a highly water stable metal-organic framework (MOFs) into membranes would meet the requirements for the efficient purification of textile wastewater. In this study, nanofiltration (NF) membranes are fabricated by incorporating MIL-100 (Fe) into the chitosan (CS) through film casting technique. The effect of MIL-100 (Fe) loadings on chitosan characterized by FT-IR, XRD, contact angle measurement, FESEM-EDS, XPS, zeta potential, and surface roughness analysis. The membrane characterization confirmed the enhanced surface roughness, pore size, surface charge, and hydrophilicity. The CS/MIL-100 (Fe) membrane exhibited an improved pure water flux from 5 to 52 L/m2h as well as 99% rejection efficiency for cationic methylene blue (MB) and anionic methyl orange (MO). We obtained the rejection efficiency trend for the MB mixed salts in the order of MgSO4 (Mg2+ - 51.6%, SO42− - 52.5%) > Na2SO4 (Na+ - 26.3%, SO42− - 29.3%) > CaCl2 (Ca2+ - 21.4%, Cl− - 23.8%) > NaCl (Na+ - 16.8%, Cl− - 19.2%). In addition, the CS/MIL-100 (Fe) composite membrane showed excellent rejection efficiency and antifouling performances with high recycling stability. These stunning results evidenced that the CS/MIL-100 (Fe) nanofiltration membrane is a promising candidate for removing toxic pollutants in the textile dyeing wastewater. Graphical abstract of dye and salt removal by CS/MIL-100 (Fe) membrane. [Display omitted] •Hydrophilic MIL-100 (Fe) used as nanofillers for a novel composite membrane.•CS/MIL-100 (Fe) composite enhanced the membrane permeability and rejection ability.•CS/MIL-100 (Fe) membranes exhibited effective rejection of ions and dyes.•CS/MIL-100 (Fe) membranes had good stability during the long-term test.