The effects of magnesium hydroxide (Mg(OH)2) on the characteristics and performance of polyethersulfone membranes (PES) for water treatment

Abstract

Surface water is commonly used as a source of clean water, but increasingly, surface water is contaminated with various foulants. Humic acids (HAs) are a natural organic matter predominant in ground and surface waters. HAs can reduce the quality of water. This study aims to investigate the results adding magnesium hydroxide, or Mg(OH)2, to modify polyethersulfone (PES) membranes by determining the characteristics and performance of the membranes. The mixed-matrix membranes were prepared using PES and various amounts of modified Mg(OH)2 (0%, 1%, and 1.5% wt) as nanoparticle additives. A scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and water contact-angle analysis were used to characterize the membranes, followed by a membrane performance test (flux, permeability, and selectivity of the membrane) using a dead end ultrafiltration module. It can be concluded that Mg(OH)2 can improve the hydrophilicity of PES membrane with decreasing the water contact angle from 84.2° (pure PES membrane) to 68° (modified membrane), where ultrafiltration membranes with the highest permeability coefficient are obtained at 1.5% wt of Mg(OH)2 with a value of 41.94 L/m2.h.bar and a rejection percentage of 67.72%.