Development of low pressure reverse osmosis membrane for desalination process

Abstract

Water shortage has become a real problem at global level and therefore, new and innovative technologies were established to provide sustainable solutions to water crisis. One of the effective approaches to resolve the global challenges is introducing the membrane-based desalination. Reverse Osmosis (RO) is a pressure driven membrane process which becoming increasingly popular and widely used for water purification applications that require high salt rejection such as brackish and seawater desalination. In this study, the influence of Sodium dodecyl sulphate (SDS) surfactant in producing the finest membrane for desalination were investigated in terms of performance, morphological structure and molecular orientation. From a polymer blending of polysulfone (PSF)/N-Methyl-2-Pyrrolidone (NMP)/polyvinylpyrrolidone (PVP)/sodium dodecyl sulphate (SDS) were formulated for making of low pressure reverse osmosis (LPRO) membrane. In order to examine the influence of SDS surfactant, different concentration from 0 wt% to 3 wt% were employed for desalination application of 10,000ppm (brackish water) and 50 000ppm (seawater). Experimental data showed that the increasing of 0.5wt% in surfactant produced higher pure water permeation (PWP) and flux. At 2.5wt% of SDS, the LPRO membranes showed the highest PWP of about 44.8L/m2h and brackish water flux at 45.58L/m2h. Meanwhile, at 3.0wt%, the highest flux of seawater at 39.37L/m2h was obtained. Moreover, the optimized LPRO (2wt% of SDS) membrane performed high rejection ratio of 90.9% for brackish water and 90.4% for seawater concentration of 10,000ppm and 50,000ppm, respectively. Therefore, the findings revealed that the fabricated LPRO membrane having a good potential to be used as eco-efficient desalination process of brackish water and seawater technology.