Polyamidoamine dendrimers-Mil-125(Ti) MOF embedded polyethersulfone membrane for enhanced removal of heavy metal, antibiotic and dye from water

In the current study, the solvo-thermal method was used to synthesize Mil-125(Ti). Then, polyamidoamine dendrimer G.02 (PAMAM) was produced by Michael's addition reaction and then loaded on the surface of Mil-125(Ti) to produce Mil-Den nanocomposite. The FESEM images, XRD pattern and FTIR analyses were used to investigate the physicochemical and structural features of synthesized Mil-Den. Next, the prepared Mil-Den nanocomposite was used for the fabrication of mixed matrix polyethersulfone (PES) membranes. The morphology, water flux, anti-fouling properties, hydrophilicity, and rejection of the Na2SO4 salt, Lead (II) nitrates as heavy metal, cefixime antibiotic, and six different reactive dyes were assessed. The incorporation of Mil-Den nanocomposite into PES membrane led to porosity enhancement from 66.8% for the bare membrane to 87.2% for the blended ones containing 1 wt% of Mil-Den. Also, the water contact angle of membrane was reduced from 59.2° to 31.2° by use of Mil-Den. The water flux of the membrane was remarkably increased from 17.9 to 287.6 (L/m2/h) by the addition of Mil-Den. The dye rejection for the blended membrane containing 0.2 wt% of Mil-Den nanocomposite measured 99.33%, 85.18%, 98.20%, 94.67%, 82.49% and 79.05% for RG19, RB50, RB21, RY145, RY160 and RY39, respectively. In addition, the rejection of cefixime antibiotic, lead ion, and sodium sulfate solutions were measured 80.04%, 97.36%, and 65.21%, respectively. The flux recovery ratio determined > 68% for the bare PES membrane whereas that was > 90% for the modified membrane with 0.1 wt% Mil-Den nanocomposite. Consequently, this study indicated the high potential of blended Mil-Den/PES-based membranes in water treatment.