Development Of Macroporous Adsorption Resin Immobilized Tannins And Its Adsorption Mechanism

A new macroporous adsorption resin immobilized tannins was prepared by immobilizing tannins on styrene-divinylbenzene copolymer using Mannich reaction, based on reviewing the present researches of adsorption resin and the functional polymers of plant tannins. The preparation condition of amino resin and immobilizing reaction with tannins were systematically studied, and the optimum synthesis technology was obtained.The performance of static adsorption of phenolic compounds onto this kind of resin was investigated in details and some comparision was made between macroporous adsorption resin immobilized tannins and NKA-II. The results showed that the adsorption capability of macroporous adsorption resin immobilized tannins were higher than that of NKA-II, which may be contributed to the phenolic hydroxyl group of the adsorbent. In addition, easily desorption of macroporous adsorption resin immobilized tannins was showed in experiments. The resin can be used to enrich and purify baicalin from aqueous solution, and phenol from real phenolic wastewater, with satisfactory results respectively. The studies on the thermodynamics, competitive adsorption, Infrared spectrum and Zeta potential showed that the adsorption of phenolic compound onto macroporous adsorption resin immobilized tannins is the endothermic sorption process and occurs automatically. Freundlich isotherm is suggested as the propriate type for this procedure.Furthermore, the adsorption propelling force was mainly the hydrogen-bonding interaction between the phenolic hydroxyl group of the adsorbent and the phenol. The studies on the kinetics and reaction activation energy showed that both film diffusion and particle diffusion are the rate-controlling process in the adsorption system tested. But particle diffusion is more predominant.