Effect of mining chemicals on biosorption of Cu(II) by the non-living biomass of the macrophyte Potamogeton lucens

The present work investigates the effect of some compounds commonly discharged from mineral processing plants on biosorption of heavy metals by the non-living biomass of the freshwater macrophyte Potamogeton lucens. Studies of sorption of Cu (II) in the presence of metal ions, surfactants, EDTA and cyanide were carried out at laboratory scale. The results show that copper adsorption by ion exchange on the biomass is not affected by equimolar concentrations of copper/sodium, copper/calcium or copper/iron. Non ionic surfactants (e.g. pine oil) do not modify biosorption, but the negative groups of anionic surfactants (e.g. sodium oleate) compete with the surface groups of the biomass for the free copper ions in solution. EDTA and cyanide react with copper ions producing soluble complexes that do not adsorb onto the biomass. The biosorption process is suitable for wastewater treatment when the heavy metal species are free in solution. Effluents containing metal sequestering compounds that produce soluble or precipitated species are not able to be treated by carboxyl groups based biosorbents. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.