TiO2-nanoparticles Coated Forward Osmosis Membranes for Enhanced Filtration of Textile Effluent

Abstract

Textile wastewater has been recognized as one of significant industrial wastewater sources due to its complex composition and the presence of reactive constituents such as heavy metals and salts as well as nutrients, e.g. nitrogen, sulphate and phosphate. In this research, the combination of forward osmosis with photocatalytic method was analytically considered for the recycling of textile effluent after biological treatment process. The research aims to study the feasibility in application of TiO2-nanoparticles coated on two commercially accessible FO membranes; an aquaporin (AqP) membrane and a cellulose triacetate (CTA) membrane by the way of a specially designed 3-(trimethoxysilyl) propyl methacrylate–polymethyl methacrylate–bromide (MEMO–PMMA–Br) monomer chain as a novel forward osmosis treatment method. High efficiency of reactive dye rejection of 99.9% could be achieved with this novel FO process with the use of 1 M NaCl as the draw solution, while varying reactive dye (black) at concentrations of 200, 400, 600, 800 ppm in the synthetic textile effluent. The obtained water fluxes of both FO membranes suggested that the achievement of the CTA membrane was incredibly improved after surface modification than that of AqP membrane with the increase in average fluxes of 18.03% and 11.83%, respectively. The experiments also suggested that CTA membrane gives higher water flux than aquaporin membrane for forward osmosis filtration for synthetic textile effluent. Moreover, effect of interferences in terms of dissolved anions on reactive dye removal efficiencies by the TiO2-nanoparticles coated FO membranes were also investigated.