Enhancement of Industrial Effluents Quality by Using Nanocomposite Mg/Al LDH Ultrafiltration Membranes

In this paper, Mg-Al-Acr LDH and Mg-Al-Amps LDH nanocomposites were synthesized via reacting of acrylic acid and 2-acrylamido2-methylpropansulfonic acid with Mg-Al LDH by chelation technique. The nanocomposite LDHs were applied as a hydrophilic fillers for modification of polysulfone (PSf) ultrafiltration membrane. The Mg-Al LDH/PSf, Mg-Al-Acr LDH/PSf and Mg-Al-Amps LDH/PSf membranes were fabricated using induced phase-blending method. The chelated LDHs and UF membranes were characterized using Atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analyses. In contrast to the neat PSf film, the Mg-Al-Acr LDH/PSf and Mg-Al-Amps LDH/PSf nanocomposite membranes exhibited higher pore size, porosity, hydrophilicity and lower surface roughness. The finger-like structures demonstrated for neat PSf membrane in cross-section SEM images were collapsed in Mg-Al-Acr LDH/PSf and Mg-Al-Amps LDH/PSf nanocomposite membranes. The synthesized PSf films were optimized in the presence of suitable content of hydrophilic LDHs (0.1 wt%). Not only the modified PSf membranes, when compared with the neat membrane, show a higher pure water flux of 300 and 390 l m(-2) h for 0.1 wt% Mg-Al-Acr LDH/PSf and Mg-Al-Amps LDH/PSf membranes, respectively, but also the antifouling of the optimal nanocomposite films was enhanced. Moreover, the TOC of the wastewater decreased from 140.8 to 44 and 30.8 mg l(-1), correspondingly. Finally, with a higher water permeation and humic acid rejection, those equipped films turned to be more attractive and excellent for effluent features enhancement.