Abstract: In this paper, the spherical diethanolamine based lignin was prepared by inverse suspension polymerization technique using alkaline lignin and diethanolamine as raw materials. The products were characterized by FTIR and SEM, the specific surface area and pore structure were analysed by H₂-TPD, and its adsorbility of copper ions were determined in the simulation environment which contain heavy metal. The analysis of FTIR confirmed the introduction of diethanolamine into the lignin molecular, and its N content is 1.66%. From the kinetic curve, it can be seen that in the beginning half hours, the adsorption capacity grows rapidly, then it gets the balance in six hours, the adsorption capacity increased with temperature increase. The adsorption capacity achieves maximum as 24.12 mg/g when adsorbent is 4 g/L. The adsorption capacity was enhanced greatly compared with alkaline lignin and diethanolamine based lignin, which adsorption capacity was 5.84 mg/g and 10.71 mg/g respectively.

Key words: spherical diethanolamine based lignin, synthesis, reversed phase suspension technique, Cu²⁺ adsorption