Ceramic hollow fiber NF membrane incorporating UiO-66 for the chlorinated hydrocarbons removal

Chlorinated hydrocarbons (CHC) are highly toxic to human health and the ecological environment. In this study, thin-film nanocomposite (TFN) membranes doping with UiO-66 were prepared and applied to the CHC removal in groundwater. TFN membranes with UiO-66 asymmetrically distributed in the polyamide (PA) layer were prepared by incorporating UiO-66 in the aqueous phase and the organic phase, respectively. Molecular dynamics (MD) simulation was applied to do further mechanism research. The water boundary layer surrounding UiO-66 induces a wrinkled phase interface when UiO-66 is dispersed in the aqueous phase. Also, the dissolution-diffusion model was used for investigating nanofiltration (NF) process. Water molecules show a faster dissolution rate and a higher dissolution equilibrium on the UiO-66 surface. UiO-66 exhibits twice the water number density relative to the PA due to super-hydrophilicity, which provides a greater driving force for the mass transfer of water. In addition, the diffusion coefficient of water in the UiO-66 pore is about 1.5 times that in PA. As a result, TFN(O) membrane exhibits a high pure water flux of 30.4 L.m(-2).h(-1).bar(-1) with the trichloroethylene (TCE) and trichlorobenzene (TCB) rejection above 96%. This work provides a solution for CHC removal of groundwater and a mechanistic explanation for the interfacial polymerization (IP) and separation process of doped nanoparticles.