Development of TiO2/polyvinyl alcohol-cellulose acetate nanocomposite reverse osmosis membrane for groundwater-surface water interfaces purification

Abstract

The conventional water treatment processes have limits to overcome the gap between available water sources and the water demand. So desalination is required to face this challenge. In this study, polyvinyl alcohol (PVA) blended cellulose acetate (CA) membranes incorporated nano-rods TiO2 (NRTiO2) using various concentrations from 0.1 to 0.7 wt%. Membrane hydrophilicity increased as NRTiO2 loading increased, whereas tiny additions of NRTiO2 0.5 wt% resulted in higher tensile strength (8.7 MPa) and tensile modulus (67 MPa). A 10,000 mg/L NaCl solution was used to evaluate fabricated membranes, optimized membrane performance was achieved with 0.5 wt% NRTiO2, with a salt rejection (Rs) 99.52 % and a flux increase of 34.2 %. As a result, adding (NRTiO2) to the polymer solution creates water paths that make water flow easier. Furthermore, the PVA-CA-NRTiO2 membranes had a significant salt rejection due to the (NRTiO2) irregular's crystal shape, the size exclusion principle, and the ion exchange mechanism. NRTiO2membrane was applied for surface water treatment and was recommended for this water source. This membrane reached the highest removal percent with 100 % for COD and BOD5. In addition the dissolved solids and chlorides were exceeding 90 %. As well as this membrane will be promising for groundwater-surface water interfaces.