“…Various adsorbents, such as clays [ 21 , 22 , 23 ], functionalized magnetic chitosan nanoparticles [ 24 , 25 , 26 ], carbon adsorbents [ 27 , 28 , 29 , 30 ], biosorbents [ 31 , 32 , 33 ], hydrogels [ 34 , 35 , 36 , 37 , 38 ], and ion exchangers [ 39 , 40 , 41 , 42 ], can be used to recover various metal ions from aqueous solutions. The recovered metals have wide applications in catalysis, pyrotechnics, coal chemistry, and other fields [ 43 , 44 , 45 , 46 , 47 , 48 ]. However, the practical application of recently developed polymeric sorbents has been limited [ 49 , 50 , 51 ].…”