The derivatives containing carboxyl groups due to the reaction with 2-mercaptobutanedioic acid had an adsorption capacity for Cu(II), Ni(II) and Pb(II) of 36 mg g1,9 mg g1 and 104 mg g1 respectively.
The derivatives with amino and carboxyl groups due to the reaction with cysteine had an adsorption capacity for Cu(II), Ni(II) and Pb(II) of 22 mg g1, 8 mg g1 and 28 mg g1 respectively.