Cellulosic adsorbent functionalized with macrocyclic pyridone pentamer for selectively removing metal cations from aqueous solutions

Metal selective adsorbent (MCPP-SA-MCC) was synthesized by the reaction of macrocyclic pyridone pentamer (MCPP) with succinic acid anhydride modified microcrystalline cellulose (SA-MCC). Selectivity of the tailor-made adsorbent to metal cations was studied by measuring its competitive adsorption ability to nine metal cations (Ba2+, Pb2+, Cd2+, Mn2+, Cu2+, Co2+, Ni2+, and Cr3+). It was found that MCPP-SA-MCC exhibited a patterned recognition of metal cations remarkably correlated with the metal cation radius. In the simulated wastewater effluent containing nine metal cations, MCPP-SA-MCC dominantly adsorbed Ba2+, which has a larger ion radius than others, and 75% of Ba2+ was removed while others less than 18%. These features indicated the promise of MCPP-SA-MCC as a candidate to remove heavy metal cations from aqueous solution selectively.