Preparation of Lignin Based Anion Exchanger for Nitrate and Phosphate Removal

摘要

Tertiary amino alkali lignin (TA-AL) was successfully synthesized by a two-step approach;its application as an adsorbent for nitrate and phosphate ions in effluents was investigated.TA-AL was characterized by FT-IR,zeta potential,SEM,and elemental analysis.Kinetic and equilibrium adsorption isotherms were determined to investigate the adsorption capacity of TAAL.The results revealed that TA-AL had a very strong adsorption capacity towards anions;the value of pHPZC (PZC,point of zero charge) was about 9.2.The adsorption of nitrate and phosphate ions was related to effluent pH and initial anion concentration.The maximum absorption of nitrate and phosphate ions was about 26.9 and 18.4 mg/g when the initial concentration of the ions was 50 mg/L.The adsorption kinetics conformed to the pseudo-second-order kinetic equation,and the equilibrium data were suitably expressed by the Freundlich model.The regeneration studies confirmed that the lignin-based material was a promising adsorbent for nitrate and phosphate ions in water.