Micro-/Nano-Dual-Scale Porous Composite Membranes for the Separation of Nanopollutants from Water

Novel micro-/nano-dual-scale porous composites have been fabricated for nanopollutant filtration by powder metallurgy via four-step sintering of Ti, Al, and Nb powders incorporated with SiO2/ZrO2/Y2O3/MgO/ZnO nanoparticles, respectively. Afterward, phase formation, surface morphology, and pore features of the porous composites have been characterized with the changes of heat-treatment temperatures and additive nanoparticles. The separation efficiency of as-prepared Ti-48Al-6Nb porous alloy and porous composite membranes for 50 mg/L TiO2 nanopollutants from pure water can be calculated through determining the change of TiO2 concentrations after filtration. Compared with the Ti-48Al-6Nb porous alloy membrane with a separation efficiency of 89.91%, all porous composite membranes can enhance the separation efficiency up to 99.80%. In particular, favorable contributions of the porous composite membrane with nano-SiO2 are further ascertained by maintaining a high separation efficiency of above 99.95% after repe...