CuO nanoparticles as modifiers for membranes: A review of performance for water treatment

Copper (II) oxide (CuO) nanoparticles can be used to modify membranes used in water treatment. They greatly increase the adsorptive properties of membranes and their overall efficiency, making them more efficient in handling extremely difficult pollutants. This paper aimed to critically analyse literature published after the year 2015 on the subject of CuO-modified membrane and to identify the core landmarks and breakthroughs in the research area. The goal was to examine how the CuO modifier affects membrane performance. The CuO modified membranes were mostly applied as a barrier for solute rejection, a surface for the catalytic degradation/ reduction of pollutants and as an interface for pollutant binding/adsorption. In the application areas, CuO modified membranes showed a > 95 % rejection efficiency in most cases. The modified membranes are highly reusable and have a > 60 % flux recovery ratio after 5 cycles. Biofouling performance of CuO-modified mem-branes showed the modifier's toxicity to biofoulants. The financial sustainability of the membrane process needs to be considered because this has been a key challenge for membrane processes in recent years. The review observed that challenges contributing to the limitation of CuO modified membranes at an industrial scale include membrane cake formation, fear of uncertainty in industrial market penetration, and fear of safety as a result of environmental concerns around nanomaterials. We believe that the paradigm of membrane modification using CuO NPs can induce more breakthroughs in membrane science and technology.