Premium
Chemical speciation and bioavailability of copper: Uptake and accumulation by eichornia
Author(s) -
Nor Yahya M.,
Cheng H. H.
Publication year - 1986
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620051102
Subject(s) - copper , chemistry , bioavailability , environmental chemistry , bioaccumulation , genetic algorithm , humic acid , dissolved organic carbon , chelation , biotic ligand model , lability , metal , inorganic chemistry , organic matter , organic chemistry , ecology , bioinformatics , fertilizer , biology
The uptake of copper by water hyacinth ( Eichornia crassipes ) was studied using solution culture techniques in the greenhouse. The bioassays indicated that the uptake of copper was a direct function of its speciation. For example, only free Cu 2+ was absorbed by the plant in the presence of strong ligands such as EDTA and humic acid. Other ligands tested (fulvic acid, amino acids and simple organic acids), however, failed to suppress the uptake of copper even when the free Cu 2+ in solution initially was negligibly small. Copper could have been taken up directly by the plant as various complexes or in the free Cu 2+ form after dissociation from the ligands prior to uptake. Complete inhibition of copper uptake in the presence of humic acid, in contrast to fulvic acid, suggests that the chemical stability constants of these complexes with copper were not correlated to the metal's bioavailability. The potential of Eichornia for removing heavy metals from wastewaters is demonstrated by its tremendous capacity to bioaccumulate copper. Depending on the presence or absence of ligands, from 200 to more than 2,400 μg Cu g −1 dry matter could be taken up by the plant.