An Effective Nano-fibrous Membrane Containing Al-MOF for Water Treatment

Nano-fibrous membranes have recently received much attention in the water treatment industry, due to their unique properties such as their porosity and high specific surface area. In this research, electrospun polyvinylidene fluoride (PVDF) membranes modified with MIL-53 metal organic framework (MOF) were fabricated and their performance in heavy metal elimination, dye, and salt rejection was investigated. The structure of synthesized MOF was studied through fourier transform infrared (FTIR), and X-ray diffraction (XRD), while the thermal stability was investigated using thermal gravimetric analysis (TGA). In addition, the morphology of membranes was surveyed with scanning electron spectroscopy (SEM). The efficiency of the membranes was measured by some tests such as pure water flux, removal of dyes, heavy metals and salts. The effect of the additive amount was investigated. In this respect, the modified membranes exhibited higher pure water flux (PWF), and lower contact angle due to their more hydrophilic nature in compare with non-modified membranes. The pure water flux for the membrane containing 5 wt% of MOF compared to the membrane without additives has increased more than 3 times and reached to 360L/m2h. In salts, dyes, and heavy metals rejection, membranes with 2, 5, and 1 wt% additive have performed best, respectively. The maximum removal for MgSO4 was 60.9%. Membrane efficiency in removing methyl orange was better and membrane 4 was able to remove 75% of this dye. The performance of the membranes was better in the rejection of pb and membrane 2 removed 97% of this metal. Pure water flux has changed little over time and, dyes removal has decreased by 26% in 12 hours.