<p>Increasing population growth, climate change, and industrial expansion worsen freshwater scarcity. Brackish water is excessively available and can supplement inadequate freshwater supplies. It is also an alternative to freshwater as it is low in salinity. Herein, we have developed dense polymeric membranes from polyamide-6 chitosan and cellulose acetate with incorporation of ZiF-8 via the solution casting method. The fabricated membrane was characterized by FTIR, XRD, SEM, TGA, and tensile testing to evaluate its structural, crystalline properties, surface morphology, thermal behavior, and mechanical characteristics, respectively. All the polymeric membranes processed multifunctional behavior and amorphous behavior with dense and compact surface morphology. These films also sufficiently exhibited thermal stability, and it was observed that increasing the amount of cellulose acetate improves the tensile mechanical behavior. These fabricated membranes were treated with a 5000 ppm solution of sodium chloride (NaCl) to determine their potential with an operating pressure of 20&#xa0;bar. The impact of the thickness of the membrane was further explored, and the most suitable thickness was established for efficient water flow with efficient salt rejection. An increasing amount of cellulose acetate was also investigated to optimize the best formulation for accelerated water desalination properties. It was found that the different formulations of the polymeric membrane have different salt rejections and variable water flus. The polymeric membrane with 150-micron thickness and the maximum amount of ZiF-8 exhibited 82% salt rejection with 1.75 Kg/m² water flux. Hence, the results confirmed that the fabricated membranes would be a potential material for the treatment of brackish water. Graphical abstract.</p> Graphical Abstract <p></p>