In this research, the membranes were stemmed from the biopolymer containing quaternary amine moieties (Chitosan and Chitosan-palm) for nanofiltration purposes. The developed membranes were fully featured using different characterization techniques (SEM), (TGA), zeta potential, and contact angle measurement. The membrane’s features were systematically characterized in hydrophilicity contact angle, surface morphology, and charge on the surface, acidity, and water permeability. The permeability of water for the chitosan membrane with palm was 3.04 ± 0.12 L m⁻² h⁻¹bar⁻¹ twice as the average permeability of the pristine chitosan membrane 1.68 ± 0.04 L m⁻².h⁻¹.bar⁻¹. The salt rejection was enhanced (from 5% for NaCl to 70% for MgCl₂ in the same condition). These membranes could endure up to 22 bar. Therefore, the developed Chitosan and chitosan-palm membranes are more noteworthy for water treatment than the other commercially available membranes and costly activated carbons.

Nanofiltration membranes were successfully created using multi-walled carbon nanotubes (MWCNTs) and MWCNTs modified with amine (MWCNT-NH₂) and carboxylic groups (MWCNT-COOH). Chitosan (CHIT) and chitosan–glutaraldehyde (CHIT-G) were utilized as dispersants. Sonication, SEM, and contact angle were used to characterize the as-prepared membranes. The results revealed that the type of multi-walled carbon nanotubes (MWCNT, MWCNT-COOH and MWCNT-NH₂) used as the top layer had a significant impact on membrane characteristics. The lowest contact angle was 38.6 ± 8.5 for the chitosan-G/MWCNT-COOH membrane. The surface morphology of membranes changed when carbon with carboxylic or amine groups was introduced. In addition, water permeability was greater for CHIT-G/MWCNT-COOH and CHIT-G/MWCNT-NH₂ membranes. The CHIT-G/MWCNT-COOH membrane had the highest water permeability (5.64 ± 0.27 L m⁻² h⁻¹ bar⁻¹). The findings also revealed that for all membranes, the rejection of inorganic salts was in the order R_(NaCl) > R_(MgSO4).

Fresh water scarcity and pollution turn out to be a most serious issue throughout the world due to the rapid population growth. The application of nanomaterials (NMs) for the removal of pollutants from water has attracted significant attention. The nanofiltration membrane was fabricated through the evaporative casting (EC) method using multiwalled carbon nanotubes (MWCNT) and chitosan (CHIT) as the surfactant to enable water purification. The developed EC membrane properties were characterized in mechanical, surface charging (zeta potential), surface morphology, and hydrophobicity properties. Results demonstrated that incorporation of MWCNT and the biopolymers (chitosan) resulted in suitable developments in mechanical properties of the membrane. For example, the membrane has shown values for tensile strength (28 ± 1 MPa), elongation (10.2 ± 1.2%), Young’s modulus (1.2 ± 0.1 GPa), and toughness of (1.9 ± 0.2 J/g). When more significant changes were investigated on the surface morphology of the EC membrane, it was observed that the pores on the surface morphology of the EC membrane decreased as the evaporative casting method was used. Moreover, the permeability of the membrane towards water, inorganic salts, and pH effect on salt rejections was studied using the NF/RO system. These established nanocomposite membranes signify the promising candidates for fresh water desalination and elimination of organic impurities.