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Copper and nickel partitioning with nanoscale goethite under variable aquatic conditions
Author(s) -
Danner Kelsey M.,
Hammerschmidt Chad R.,
Costello David M.,
Burton G. Allen
Publication year - 2015
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.2977
Subject(s) - goethite , environmental chemistry , ionic strength , copper , nickel , chemistry , bioavailability , adsorption , metal , aquatic ecosystem , inorganic chemistry , aqueous solution , organic chemistry , biology , bioinformatics
Metal contaminated sediments can be toxic to aquatic organisms and are common in human‐dominated ecosystems, which results in metals being a leading cause of ecosystem impairment. Bioavailability of metals is influenced by their affinity for dissolved and solid‐phase ligands, including iron (Fe) oxyhydroxides, which have been hypothesized to reduce metal toxicity in sediments. The authors examined the adsorption kinetics of copper (Cu) and nickel (Ni) with goethite (α‐FeOOH) and characterized the influences of solute metal concentration, pH, ionic strength, and humate concentration on steady‐state partitioning of the metals with goethite under conditions representative of natural aquatic environments. Copper and Ni readily adsorbed to goethite, and steady‐state partitioning was achieved within 2 h. Although ionic strength had no effect on metal partitioning, adsorption of Cu and Ni to goethite was enhanced by alkaline pH and reduced by competition with humate. Because distribution coefficient ( K D ) values for Cu and Ni from the present study are comparable to values measured in natural systems, the authors hypothesize that goethite may contribute significantly to the adsorption of both Ni and Cu to particles in the environment. The authors suggest that incorporating binding by Fe oxides in metal bioavailability models should be a priority for improving risk assessment of metal‐contaminated oxic sediments. Environ Toxicol Chem 2015;34:1705–1710. © 2015 SETAC