Study of the adsorption of copper(II) ions from water onto wood sawdust, pulp and lignin

The adsorption of copper(II) ions from aqueous solution onto sawdusts from different kinds of wood, pulp and Kraft lignin has been studied. The results of batch studies showed that Kraft lignin was a good adsorbent over the whole concentration range studied, hard woods (oak and black locust) were good when the Cu(II) ion concentration in the aqueous solution was high, while soft woods (poplar, willow, fir) and pulp were good for the adsorption of Cu(II) ions when the latter were present over the low concentration range. The maximum adsorption capacities of the adsorbents investigated towards Cu(II) ions were in the 1.77-9.35 mg/g range. Isotherms were used to obtain the corresponding thermodynamic parameters. Almost complete Cu(II) ion desorption was achieved using 0.1 M mineral acid solutions. The regenerated adsorbents could be used in several adsorption/desorption cycles.