The global problem of the scarcity of drinking water resources, caused by various reasons such as pollution from human activities, environmental degradation and climate change, has affected human life all over the world. One of the best and most effective ways available to solve this challenge is wastewater treatment. Membrane processes for water treatment plants are new methods that have been developed over the last fifty years. These new processes have many advantages, such as low current cost and high efficiency. In a membrane process, there are generally two phases that are physically separated by a third phase (membrane). The membrane controls the mass transfer between the two phases. Membranes, which are considered as the heart of the membrane process, are prepared with different structures. Nanofiltration is one of the most widely used membrane processes that has been used in various industrial and commercial fields and new applications have been planned for it. One of the applications considered for membrane processes is the separation of different water ions. For example, the purification of drinking and agricultural water from heavy binary metals, which often cause many environmental problems due to their toxicity, can be carried out by membrane processes. In this study, using the phase inversion method, a nanofiltration membrane was fabricated on the basis of a mixture of poly(vinyl chloride) and poly(methyl methacrylate) polymers. For this work, tetrahydrofuran was used as a solvent. Experimental design method using Taguchi model was used to obtain the optimal membrane and also FT-IR spectroscopy was used to investigate the formation of the desired chemical bonds. In the experimental design, three factors including weight percentage of polymers, solvent evaporation time and membrane thickness were considered as variables and two factors including flow rate and rejection were considered as dependent variables or response variables. It was found that the b
