Design, synthesis and study of a new polymer – ion liquid nanofiltration membrane modified with iron / choline chloride nanocomposite to remove water contaminants by experimental design (DOE) method

In the present study, polyetersulfone membrane was modified with ferric chloride nanocomposite to improve membrane performance in removing contaminants. Choline chloride ion liquid was used for the first time. In order to determine the properties and morphology, FTIR, contact angle, porosity, BET, TGA, DSC, SEM, transmission flux and membrane clogging analysis were investigated. In order to find the optimal removal conditions, pH and temperature were selected as effective variables and the necessary experiments were designed and performed using Design Expert software and response surface method. The results showed that the best performance of orange 7 dye removal with a membrane of 0.5 wt% nanocomposite and a concentration of 5 μM contaminant at pH 6.7 and a temperature of 33.9 ⁰C, which removes 97.6% of the contaminant. The forecasting model and the results were in good agreement. Water permeability in the modified membranes increased due to changes in the structure and hydrophilicity of the membrane surface, which led to a decrease in clogging and an increase in the amount of return flux compared to the pure membrane.