Poly(methacylic acid-co-maleic acid) grafted nanofibrillated cellulose as a reusable novel heavy metal ions adsorbent

• Aerogel adsorbent based on nanofibrillar cellulose was prepared.
• The cellulose aerogel was modified by grafting methacrylic and maleic acid to boost the adsorption capacity.
• The modified aerogel showed improved adsorption toward wide range of heavy metal.
• The cellulose aerogel could to be readily regenerated and reused without any loss of the adsorption capacity.

A poly(methacrylic acid-co-maleic acid) grafted nanofibrillated cellulose (NFC-MAA-MA) aerogel was prepared via radical polymerization in an aqueous solution using Fenton's reagent. The ensuing aerogel, in the form of a rigid porous material, was characterized by FTIR and NMR and used as an adsorbent for the removal of heavy metals from aqueous solutions. It showed an efficient adsorption, exceeding 95% toward Pb2+, Cd2+, Zn2+ and Ni2+ when their concentration was lower than 10 ppm and ranged from 90% to 60% for a metal concentration higher than 10 ppm. Over 98% of the adsorbed metal ion was recovered using EDTA as a desorbing solution, and the subsequent washing allowed the aerogel to be reused repeatedly without noticeable loss of adsorption capacity. It was concluded that the (NFC-MAA-MA) aerogel may be used as a high capacity and reusable sorbent material in heavy-metal removing processes.