Pharmaceutical rejection by membranes for wastewater reclamation and reuse

Abstract

Various membranes, which have different materials and nominal molecular weight cut-offs (MWCO), were compared in terms of rejection of ibuprofen and removal of effluent organic matter (EfOM) from membrane bioreactor (MBR), because pharmaceutical compounds contain a potential risk and EfOM is the precursor of carcinogenic disinfection by-products when reusing for drinking water source. To provide equivalent comparison with respect to hydrodynamic condition, mass transfer parameter, J0/k ratio, was used. A tight-UF membrane with a molecular weight cut off of 8,000 daltons exhibited 25∼95% removal efficiencies of ibuprofen with a molecular weight of 206 with and without presence of EfOMMBR. EfOMMBR caused the reduction of ibuprofen removal efficiency for UF membrane. Rejection of EfOMMBR by UF and NF membranes ranged 29∼47% and 69∼86%, respectively. UF membrane could successfully remove ibuprofen at lower J0/k ratio range (≤1) in organic free water but could not efficiently reject ibuprofen with a relatively hydrophilic EfOMMBR (SUVA ≤3).