Ion-imprinted modified molecular sieves show the efficient selective adsorption of chromium(vi) from aqueous solutions

Facile fabrication of ion-imprinted Fe3O4/carboxymethyl cellulose magnetic biosorbent: removal and recovery properties for trivalent La ions

An Fe₃O₄/carboxymethyl cellulose (Fe₃O₄/CMC) magnetic biosorbent was prepared using the ion-imprinting technology, where La(iii) was used as the template ion. The morphology and structure of Fe₃O₄/CMC were characterized by SEM, FTIR and XRD. It is found that nano Fe₃O₄ with inverse spinel structure can distribute in CMC and endow the composite with good magnetic properties. The adsorption performance such as adsorption capacity, influence of pH and initial concentration were fully explored. The prepared Fe₃O₄/CMC is revealed to have good adsorption properties with Q _max of 61.5 mg g^-1, in line with the pseudo-second-order kinetic model. When handling the multi-ion coexistence solution of Cu(ii), Ni(ii) and Cd(ii), Fe₃O₄/CMC shows high selective adsorption for La(iii). Meanwhile, cycling experiments find that the adsorption capacity is only slightly reduced (less than 5%) after 5-time reuse. Good adsorption properties, high selectivity and easy recovery give the newly-synthesized Fe₃O₄/CMC biosorbent broad application potential in the treatment of La(iii)-containing wastewater.