Effects of using different ultrafltration membranes on the removal efficiency of antibiotic resistance genes from secondary effluent

Antibiotic resistance genes (ARGs) are emerging environmental contaminants that are considered to be a real threat to human health. The use of polyvinylidene fluoride (PVDF) and polyether sulfone (PES) ultra filtration (UF) membranes for the removal of ARGs, int I 1, 16S rDNA and organic contaminants from water produced by a municipal wastewater treatment plant has been investigated. Removal rates for ARGs through PES filtration was found to be 12% higher for the PVDF membrane, with the removal rates for ARGs of a UF membrane with a 50 kDa molecular weight cut-off limit found to be 5% higher than that for a 100 kDa UF membrane. All the UF membranes could effectively remove fulvic acids, soluble metabolites and humic acids with fluorescence characteristics from raw water, with the PES 50 kDa UF membrane capable of completely removing humic acids and 27.7% of dissolved organic carbon (DOC). The levels of ARGs present were positively correlated (p < 0.05) with DOC, int I 1 and 16S rDNA levels, therefore, the presence of organics, int I 1, and other microorganisms all have the potential to affect removal efficiency of ARGs.