نمك‌زدايي از محلول‌هاي آبي با استفاده از غشاهاي PVA حاوي NH2-MIL-53(Al) و COF-SO3H به روش تراوش تبخيري

Desalination of aqueous solutions using PVA membranes containing NH2-MIL-53(Al) an‎d COF-SO3H by pervaporation method

شيمي تجزيه

Population growth has made it difficult to provide clean water. Ions such as magnesium cause water hardness. Polymer membranes combined with mineral adsorbents are a new solution for water purification. In this study, composite membranes of PVA/NH2-MIL-53(Al) an‎d PVA/COF-SO3H were synthesized an‎d eva‎luated. The structure of the membranes was characterized using field emission scanning electron microscopy (FESEM), contact angle measurement, an‎d energy-dispersive X-ray spectroscopy (EDX). Furthermore, the performance of the membranes in removing sodium an‎d magnesium ions from aqueous solutions was investigated. The results demonstrated that the incorporation of NH2-MIL-53(Al) an‎d COF-SO3H nanoparticles markedly improved the membra properties an‎d enhanced its efficiency in separation processes.Permeability an‎d rejection tests revealed that the membranes containing NH2-MIL-53(Al) an‎d COF-SO3H exhibited higher flux, greater salt rejection, an‎d better hydro‎philicity compared to the pristine PVA membrane an‎d the MIL-53(Al)-based membrane. Moreover, sodium an‎d magnesium ion removal in the modified membranes was significantly increased. To investigate desalination performance an‎d to study parameters such as concentration, temperature, an‎d pH, the Central Composite Design (CCD) method was employed.The optimized conditions for sodium ion removal using the PVA/NH2-MIL-53(Al) membrane were found at a temperature of 50 °C, concentration of 282 ppm, pH of 5.41, with a permeate flux of 3.59 kg/m²•h an‎d a rejection rate of 99.6 %. For magnesium ion removal with the same membrane, the optimal conditions were a temperature of 50.5 °C, concentration of 282ppm, pH of 6.07, with a permeate flux of 5.83 kg/m²•h an‎d a rejection rate of 99.6%. The optimized conditions for sodium ion removal using the PVA/COF-SO3H membrane were a temperature of 60 °C, concentration of 720 ppm, pH of 5, with a permeate flux of 3.61 kg/m²•h an‎d a rejection rate of 99.7%. Both membranes showed high salt rejection efficiency in the pervaporation process.Overall,the results indicate that mixed-matrix membranes based on PVA/NH2-MIL-53(Al) an‎d PVA/COF-SO3H exhibit excellent performance an‎d can be considered as highly efficient can‎didates for desalination an‎d mineral ion removal in drinking water treatment applications.

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