Novel preparation of ceramic nanofiltration membrane for the removal of trace organic compounds

Abstract

In this research, ceramic ultrafiltration (UF) membrane was modified to nanofiltration (NF) membrane by simple and novel filtration coating with approximately 45 nm of alumina-zirconia (Al-Zr) nanoparticles. The prepared ceramic NF membrane showed excellent performance with 15 LMH/bar of specific water flux, similar to 1,000 Da of molecular weight cut-off, and 58% of CaCl2 rejection. The removal efficiency of tested trace organic compounds (TrOCs) was ranged from 2.2% +/- 0.3% (caffeine) and 65.0% +/- 2.1% (geosmin) at pH 7.4, and the major removal mechanisms of the prepared ceramic NF membrane were the size exclusion and electrostatic adsorption originated from the thick cross-sectional layer of positively charged Al-Zr nanoparticles deposited on the pores of ceramic UF membranes. The novel coating method for preparing ceramic NF membrane is expected to be applicable for the commercial manufacturing processes to remove TrOCs.