Novel Chitosan–MOF Composite Adsorbent for the Removal of Heavy Metal Ions

A novel chitosan–MOF composite was first synthesized and used in the adsorptive removal of heavy metal ions. The effects of time, temperature, and pH were investigated. The results show that after 8 h of adsorption, the maximum adsorption capacity of Cr(VI) was 93.6 mg g−1 at pH 2 and a temperature of 40 °C. The adsorption capacity of Cu(II) was 50.6 mg g−1 at pH 5 and 60 °C, while that of Ni(II) reached about 60 mg g−1 at pH 5 and 20 °C. The adsorptive mechanism was a pseudo-second-order model (R2 > 0.979). The chitosan–MOF composite performs well in the removal of heavy metal ions.