Immobilization of Persimmon Tannin on Cellulose Viscopearls and Removal of Caffeine from Aqueous Solution

Abstract

An eco-friendly adsorbent was prepared by immobilization of Persimmon Tannin (PT) in cellulose viscopearls to remove caffeine. The immobilization time within a range of 1-42days was performed. Batch adsorption experiments were studied for different Persimmon Tannin on Cellulose Viscopearls (PTIC) gel samples, adsorbent dosage, and initial caffeine concentration. FTIR indicated that PT was successfully immobilized onto viscopearls. SEM images showed differences especially on particle size and shape, between control, day7, and day28 of PTIC gel samples. The adsorption capacity results showed that removal of caffeine as the amount of adsorbed increased, the percentage of caffeine adsorption increased accordingly, but it decreased with the increased in initial caffeine concentration. Results for different PTIC gel samples showed that day 42 PTIC sample exhibits the highest adsorption capacity of caffeine solution of 43.3mg/g. The samples showed water contents in the range of 343-324%.The equilibrium data were analyzed using Freundlich and Langmuir equations. It suggested that viscopearls acted to be a suitable insoluble matrix to immobilized PT, instead of using crosslinkers.