Significantly Enhancing Cu(II) Adsorption onto Zr-MOFs through Novel Cross-Flow Disturbance of Ceramic Membrane

Novel cross-flow disturbance of ceramic membrane was used for the first time to enhance the adsorption of highly toxic Cu­(II) onto Zr-based metal–organic frameworks (Zr-MOFs). Effects of temperature and pH were investigated on the adsorption process of Cu­(II) onto the MOFs using the jar test. The results showed that the MOFs can well adsorb Cu­(II) (59.8 mg g–1) at a pH of 6 and a temperature of 40 °C. On the basis of this, the MOFs were then added into a novel cross-flow ceramic membrane filtration system. Effects of the operation temperature and membrane pore size were also investigated on the adsorption process. The results showed that Zr-MOFs adsorption of Cu­(II) increased with temperature. The ceramic membrane with a pore size of 200 nm exhibited better Cu­(II) removal and membrane flux than did the 50 nm membrane, as well as better kinetic data fit of the pseudo-second-order model. With the aid of cross-flow disturbance of ceramic membrane, the capacity was incredibly increased to 988.2 mg g–1 at a pH of 6, temperature of 40 °C, cross-flow velocity of 4.5 m s–1, and trans-membrane pressure of 0.05 MPa. The principal advantages of this method are a significant enhancement of adsorption onto the Zr-MOFs in the removal of Cu­(II) and convenient application in the continuous treatment of heavy metal wastewater. This can be used as an effective method in continuous adsorptive removal of heavy metals from wastewater.