The adsorption behavior of uremically-toxic creatinine, physiologically-beneficial α-amylase and lipase from aqueous solutions into pitch-based spherical activated carbons (PSACs) with different BET surface areas and pore structures was studied by UV spectrophotometry. The adsorption isotherms and dynamic adsorption curves of creatinine were investigated. The adsorption isotherms of creatinine were fitted by the Freundlich equation, from which the parameters of the equation were determined. Results showed that PSACs had better adsorptive selectivity for creatinine than for α-amylase and lipase. The equilibrium adsorption capacity of PSACs for creatinine was influenced by the solution concentration, pore structure and BET surface area of the PSACs. The larger the mesopore volume, the higher the creatinine adsorption rate. Mesopores and macropores played an important role in the adsorptive selectivity for α-amylase and lipase. The larger the pore sizes of the PSACs, the higher the adsorptive selectivity for α-amylase and lipase.
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