Study on enhancement adsorption of pipemidic acid from aqueous solution by using an amino group modified hypercrosslinked polymeric adsorbents

摘要

In the present study, an amino group modified hypercrosslinked polymeric adsorbent RDM-200 was prepared and its ability to adsorb pipemidic acid from aqueous solution was tested by using Amberlite XAD-4 as a comparison. Pipemidic acid adsorption isotherm onto RDM-200 is well described by the Freundlich model. The RDM-200 adsorption capacity for PPA was about 510.5 mg/g at 293 K, exhibited larger uptake and stronger affinity of pipemidic acid than XAD-4. The adsorption thermodynamic parameters were calculated and the adsorption was an exothermic, favorable, and more ordered process. The RDM-200 spontaneously adsorbs pipemidic acid mainly by both entropy change and enthalpy change. The RDM-200 exhibited excellent adsorption ability over the pH range 6-10, NaCl showed the positive effect.