Bimetallic Ce-UiO-66-NH2/diatomite (CUD) self-assembled membrane simultaneously with synergetic effect of phase equilibrium and rate separation

Abstract To efficiently clean oily wastewater with the linear anion polyacrylamide (APAM), selective adsorption strategy belonging to phase equilibrium separation is introduced into the membrane separation. Herein, bimetallic Ce-UiO-66-NH2/diatomite (CUD) were first synthesized by a one-step hydrothermal method and then employed as a functional layer to form CUD self-assembled membrane (CSA-membrane). CUD particles were characterized by FT-IR, XRD and SEM, and CSA-membrane was observed by SEM. The separation and the selective adsorption properties of CSA-membrane formed under the optimum conditions for APAM in oily wastewater were investigated. The results demonstrate that the size of CUD particles with proper sphericity is mainly 20 μm. Furthermore, CSA-membrane simultaneously exhibits fascinating separation and selective adsorption properties for cleaning oily wastewater, namely the concentration of oil decreases from 78.1 mg L-1 to 6.8 mg L-1, and flux of CSA-membrane reaches 789.5 L m-2 h-1. Remarkably, the adsorption capacity of CSA-membrane for APAM is 161.5 mg g-1, while showing the APAM removal rate of 51.3%. Therefore, CSA-membrane with the synergetic effect of phase equilibrium and rate separation is promising alternative for cleaning oily wastewater with APAM.