Abstract: In order to achieve efficient separation of cobalt and nickel ions from secondary resources,this study used
nickel ions (Ni2+ ) as the template and polyvinyl alcohol (PVA) and chitosan (CS) as the matrix to prepare a nickel ion-imprinted
PVA/ CS composite foam adsorbent (P-IIP). In order to accurately determine the optimal preparation process of the adsorbent,
this study optimized the key preparation conditions through systematically designed experiments,and finally identified
the optimal parameters as follows:the template Ni2+ concentration is 8 000 mg/ L,and the dosage of the cross-linking agent epichlorohydrin
is 6 mL/ g. Studies on the adsorption performance of P-IIP showed that:in a single Ni2+ solution,the solution pH
significantly affects the adsorption effect,with the optimal adsorption capacity achieved at pH from 4 to 5. When the initial concentration
of Ni2+ is 100 mg/ L,the adsorption capacity of P-IIP can reach 43. 1 mg/ g. Its adsorption behavior conforms to the
pseudo-second-order kinetic model and Langmuir isotherm model,with a theoretical maximum adsorption capacity of 67. 4
mg/ g. The experimental results of selective adsorption of Ni2+ by P-IIP in Co2+ -Ni2+ binary mixed solutions show that P-IIP has
excellent selective adsorption performance for Ni2+ . When the concentration ratio of Co2+ to Ni2+ increases from 1 to 1 000,the
separation factor of P-IIP for Ni2+ increases significantly from 11. 9 to 55. 1. Even under the condition of coexistence with highconcentration
Co2+ ,this adsorbent can still achieve efficient and selective adsorption of Ni2+ ,providing key technical support for
the effective separation of cobalt and nickel ions.

Key words: polyvinyl alcohol,chitosan,ion imprinting method,cobalt-nickel separation,selective adsorption