Simultaneous robust removal of tetracycline and tetracycline resistance genes by a novel UiO/TPU/PSF forward osmosis membrane

Abstract

The accumulation of antibiotics in the environment fosters the evolution of antibiotic resistance genes (ARGs) that cause adverse an ecological impact. In this study, we fabricated a thermoplastic polyurethane/polysulfone (TPU/PSF) composite membrane with a low structural parameter and high mechanical strength using electrospinning. UiO-66-NH2 particles and particles interfacial polymerization thin-film nanocomposite forward osmosis (UTFN) membrane were then prepared and characterized with the best-performing substrate layer of the TPU/PSF (20/80) membrane. Furthermore, the co-rejection and mechanism of tetracycline (TC) and tetracycline resistance genes (TRGs) (commonly including tetA, tetC, tetM, tetO, and tetX, as well as int1 and 16S rRNA gene) were revealed. Results demonstrated that the as-prepared UTFN membrane with 0.075 wt% particle(UTFN-0.075) achieved the highest water flux (64 L m−2 h−1) and the rejection of TC was above 99.64% using 0.5 mol (NH4)2HPO4 as the draw solution. Meanwhile, the permeability of the TRGs was lower than 10% (particularly, less than 1.4% for tetC). The rejection of electrically neutral TC was likely affected by steric hindrance, whereas the TRGs rejection mechanism could be attributed to electrostatic repulsion and pore sieving effect. As for permeability, differences in various TRGs were mainly attributed to their distribution. Therefore, the simultaneous removal of TC and TRGs by the UTFN membrane has significant application prospects for wastewater treatment.