Rapid Thermal Processing and Long Term Stability of Interlayer-free Silica-P123 Membranes for Wetland Saline Water Desalination

Abstract

The intrusion of sea water through to wetland areas creates wetland water became saline and very poor quality of water. For that, the interlayer-free silica-P123 (Si-P123) membranes calcined via rapid thermal processing (RTP) method was successfully investigated for desalination of wetland saline water. RTP method is a fast and low costs method to fabricate Si-P123 membranes compare to conventional thermal processing (CTP) method. The aims of this works are to improve the stability of silica base membranes by templating triblock copolymer P123 as carbon sources into silica matrices, and also to investigate the performance and long-term stability of Si-P123 membranes calcined under RTP method. Desalination through pervaporation process have been applied to produce potable water. Results shows the highest water flux of Si-P123 membrane calcined at 350 °C was 2.6 - 4.5 kg m-2 h-1. It was also found that this membrane was offering high surface area of 572 m2 g-1 and give mesopore structures (2.2 nm). For that, the performance of salt rejection was excellent (>98%). Furthermore, long-term stability appeared very stable for water fluxes and salt rejections measurement (over 400 h). Moreover, the permeate salt concentration was excellent (99% still under WHO limit standard (600 ppm) of potable water. It can be concluded that the stability of Si-P123 membrane was very robust for wetland saline water desalination for over 400 h of long-term stability.