Membrane fouling and modification using surface treatment and layer-by-layer assembly of polyelectrolytes: State-of-the-art review

Membrane technology has been recognized as one of the most important technologies in water desalination. However, this technology is challenged with the fouling phenomenon which causes higher operating pressure, flux decline, frequent replacement of membranes and eventually higher operating costs. Therefore, researchers have focused on developing methods to overcome this problem and to enhance the membrane resistance to fouling. In this paper, we reviewed the membrane fouling and control through surface modification techniques. Special attention was paid to the layer-by-layer assembly of polyelectrolytes (LbL) which has been widely used as a powerful technique for surface modification and multifunctional film preparation. Furthermore, detailed effects of LbL key-parameters on the membrane performance were revealed to help understanding the working mechanism of this method.