oa Influence Of Metal Oxide Nanoparticles In Membranes For Water Treatment And Desalination

Membrane technologies such as Ultrafiltration (UF), Nanofiltration (NF) and Reverse Osmosis (RO) have found widespread applications all over the world especially for water treatment and desalination. One of the keys to the development of UF/NF/RO membrane technology has been in terms of creating better filtration technologies to separate inorganic and organic substances from solution in a liquid. Great advances in UF/NF/RO generally occur due to the creation of better membranes through methods such as phase inversion combined with interfacial polymerization (IP) which lead to the formation of thin film composite (TFC) membranes. IP has become a very practical and useful technique when it comes to the generation of thin active film layer for NF and RO membranes. Recent advances showed that membranes including TFC membranes have been improved further by incorporating metal oxides nanoparticles as additives. All these methods are aimed at developing membranes with higher selectivity, rejection tendency and also overcoming fouling issues. Nanoparticles incorporated membranes have gained attention due to their ability to increase membrane permeability, mechanical properties, hydrophilicity, and selectivity in some cases. The nanoparticles which are commonly reported in NF/RO membrane fabrication are titanium dioxide (TiO2), zeolites, silica, silver, and zinc oxide (ZnO). This paper will discuss recent advances in this area as well as presenting some of the findings from our labs. Our recent works have shown that the sol-gel method can be utilised as a simple methods to produce metal oxides nanoparticles with sizes ranging from 5-20 nm. These nanoparticles have been incorporated in membranes and significant improvement has been shown in terms of permeate fluxes, rejection, contact angle and fouling propensity. Some of the nanoparticles have also been uniformly distributed within graphene-oxide sheets to reduce the tendency for agglomeration within the membranes. The impact of these advances in the future for water treatment and desalination applications will be discussed.