The adsorption of rare earth metal cerium ions by low fat pectin was determined. The effects of the adsorption time, pH of the cerium ion solution, adsorption temperature, dosage of pectin and concentration of cerium ions on the adsorption capacity of pectin were investigated. The adsorption process was analyzed by the Langmuir and Freundlich models. Using the adsorption isotherm, the related thermodynamic and kinetic parameters were calculated, and infrared spectrum analysis was performed. The results indicate that the variables studied significantly affect the adsorption of cerium ions by pectin and that the infrared spectra before and after adsorption are apparently different, implying that a chemical reaction may have occurred in the adsorption process. The Freundlich equation is better suited to describe the adsorption process compared to the Langmuir equation. The adsorption process is best described by a pseudo-first order kinetics equation. Enthalpy and entropy differences are the driving forces of the adsorption process.
