Synthesis of titania–γ-alumina multilayer nanomembranes on performance-improved alumina supports for wastewater treatment

AbstractThe γ-alumina and titania nanocrystallites were coated by sol–gel method on alumina supports respectively, as sub-layer and top-layer to prepare nanomembranes. The analysis represented a meso-porous structure for the coating layers of nanomembrane with the average pore size of 5.8 nm. The performance of the nanomembranes was investigated for permeability of demineralized water as well as rejection of ions and microorganisms using a model wastewater. Results show that in the range of 1–10 bar applied pressure, the permeability was reduced. At higher than 10 bars, with the increase of pressure, the permeability almost stayed constant due to the increase of flux. The multilayer nanomembranes showed different rejections for ions up to 25% but completely separation of the microorganisms.