Graft copolymer of acrylamide onto cellulose as mercury selective sorbent

Polyacrylamide grafted onto cellulose has been demonstrated to be a very efficient selective sorbent for removal of mercuric ions from aqueous solutions. The mercury-uptake capacity of the graft polymer is as high as 3.55 mmol/g and sorption is also reasonably fast. Thus, 0.2 g of the graft copolymer is able to extract 50 ppm Hg(II) from 50 ml water completely in 8 min. The Hg(II) sorption is selective and no interferences have been observed in the presence of Ni(II), Co(II), Cd(II), Fe(III), Zn(II) ions in 0.1 M concentrations at pH 6. Regeneration of the loaded polymer without losing its original activity can be achieved using hot acetic acid. The graft copolymer described seems very suitable for removal of large amounts of mercury in hydrometallurgical applications and may also be useful for other water treatments.