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.