Nano-ceramic membranes combined with ozonation for water treatment: Fundamentals and engineering applications

Nanotechnology-enabled water treatment is a promising solution to the challenges in the current water treatment processes, particularly to the crisis of persistent and trace emerging contaminants. Taking the integrated process coupling membrane filtration with ozonation that has been developed and widely applied in field as examples, we analyze the scientific rationale of catalytic ceramic membranes and nano-effects in membrane pores, which are considered as nano-reactors. The confinement effects are analyzed from four aspects, including the high specific surface area in membrane nano-pores, enrichment of reactants and enhancement of reaction kinetics in nano-pores, organized arrangement of water molecules in nano-reactors and the role of electric double layer during reactions. For each aspect, we build the correlation between the confinement effects and the phenomena in membrane nano-pores. Moreover, we present opportunities for the future research on nanotechnology-enabled water treatment.