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

Abstract

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-secondorder 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.

Heavy metal removal applications using adsorptive membranes

“…This meant that the decreasing charge density with increasing ionic radius decreased the interactions of the active sites with this membrane [92], as well as decreasing the adsorption capacities of different metal ions. In another research, Wang et al applied a novel cross-flow disturbance of PCMs to enhance the removal of Cu 2+ ion on Zr-based metal − organic frameworks (Zr-MOFs) [124]. It indicated that Zr-MOFs removed Cu 2+ (988.2 mg g −1 , pH = 6, T = 40 °C), and its adsorption capacity was also higher than that of MOFs (59.8 mg g −1 ) at the same condition.…”

“…Similarly, good adsorption performance was also observed for Pb 2+ , Co 2+ , and Ni 2+ ions in CTS/HAp [123] membrane. It showed an excellent adsorption capacity of Cu 2+ ion due to the oxygen and -OH multifunctional groups in Zr-MOFs [124]. Overall, the multifunctional groups, such as oxygen (O), nitrogen (N), sulfur (S), and other electron-donating materials, are necessary for the development of highperformance AMs.…”

“…12 Cu 2+ adsorption process onto Zr-MOFs via CM novel cross-flow disturbance. (Reprinted from [ 124 ]) …”

“…Similarly, good adsorption performance was also observed for Pb 2+ , Co 2+ , and Ni 2+ ions in CTS/HAp [ 123 ] membrane. It showed an excellent adsorption capacity of Cu 2+ ion due to the oxygen and -OH multifunctional groups in Zr-MOFs [ 124 ].…”

Efficient Adsorption of Pb(II) from Aqueous Solutions by Metal Organic Framework (Zn-BDC) Coated Magnetic Montmorillonite

“…These advantages make MOFs an excellent adsorbent [28,29,30]. Especially in the field of heavy metal adsorption, MOFs have shown excellent adsorption properties [31,32]. Zn-BDC is a type of MOF that can be prepared from Zn 2+ and terephthalic acid and catalyzed by triethylamine at room temperature.…”