REMOVAL OF Pb2+ AND Cd2+ FROM AQUEOUS SOLUTIONS BY CHEMICALLY MODIFIED CELLULOSE OF CASSAVA WASTE

This study investigated a novel cellulose-based heavy metals chelating material derived from cassava waste. The first part describes how the cellulose of cassava waste was extracted by the orthogonal experiment and optimization, followed by chemical modifications with succinic anhydride and polyamine to introduce carboxylic and amide functions, respectively. The obtained materials were characterized by FTIR and SEM. In the second part, the adsorption capacity of three different types of modified cellulose of cassava waste (MCCW) was evaluated by kinetic study, effect of pH, adsorption isotherms and regeneration studies. The adsorption equilibrium of MCCW 2, regarded as a promising adsorbent, was reached within 20 min for Pb2+ and 30 min for Cd2+, and the calculated maximum adsorption capacity was 476.19 mg g(-1) for Pb2+ and 289.02 mg g(-1) for Cd2+ on MCCW 2. The adsorption process was described well by Pseudo-second-order and Langmuir model. Regeneration studies indicated that the adsorption efficiencies of MCCW 2 could still be maintained at 97.40% level for Pb2+ and 93.16% level for Cd2+ even after three cycles.