Adsorption Characteristics of Tannic Acid on Fresh Calcium Phosphate in Sucrose Solution

Abstract:

The adsorption characteristics of tannic acid on fresh calcium phosphate in sucrose solution were discussed. Three kinetic models, including pseudo-first-order model, pseudo-second-order model and intraparticle diffusion model, were selected to model the adsorption processes. The adsorption of fresh calcium phosphate for tannic acid conformed to the pseudo-second order kinetic equation both in 10% sucrose solution and in the solution without sucrose, which showed that the existence of sugar molecules did not influence the adsorption dynamics model of fresh calcium phosphate. Adsorption isotherm curves of tannic acid from different concentrations of sucrose solution on fresh calcium phosphate all conformed to the Langmuir model. Sucrose concentration had certain influence on the adsorption quantity of fresh calcium phosphate for tannic acid, besides, the adsorption quantity of that in the system containing no sugar was the largest. With the increase of sucrose solution concentration, the adsorption quantity of fresh calcium phosphate to tannic acid gradually reduced.