Functionalized graphene oxide (GO), derived from pure graphite via the modified Hummer method, was used to modify commercially available ceramic ultrafiltration membranes using the vacuum method. The modified ceramic membrane functionalized with GO (ceramicGO) was characterized using a variety of analysis techniques and exhibited higher hydrophilicity and increased negative charge compared with the pristine ceramic membrane. Although the pure water permeability of the ceramicGO membrane (14.4-58.6 L/m2 h/bar) was slightly lower than that of the pristine membrane (25.1-62.7 L/m2 h/bar), the removal efficiencies associated with hydrophobic attraction and charge effects were improved significantly after GO coating. Additionally, solute transport in the GO nanosheets of the ceramicGO membrane played a vital role in the retention of target compounds: natural organic matter (NOM; humic acid and tannic acid), pharmaceuticals (ibuprofen and sulfamethoxazole), and inorganic salts (NaCl, Na2SO4, CaCl2, and CaSO4). While the retention efficiencies of NOM, pharmaceuticals, and inorganic salts in the pristine membrane were 74.6%, 15.3%, and 2.9%, respectively, these increased to 93.5%, 51.0%, and 31.4% for the ceramicGO membrane. Consequently, the improved removal mechanisms of the membrane modified with functionalized GO nanosheets can provide efficient retention for water treatment under suboptimal environmental conditions of pH and ionic strength.
Bibliographical noteFunding Information:
This research was supported by a grant (code 18IFIP-B088091-05) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure, and Transport of Korean government. In addition, this research was supported by the U.S. National Science Foundation (OIA-1632824).
© 2017 American Chemical Society.
- ceramic ultrafiltration membrane
- inorganic salts
- natural organic matters
- removal mechanisms