Development of Biologically Relevant Methods for Determination of BioavailableAluminum in Surface Waters

摘要

Surface water acidification is often accompanied by elevated concentrations ofaluminum, and the resulting aluminum concentrations are often high enough to contribute markedly to the toxicity of these waters to fish. The overall objective of this project, then, was to develop a new method for determining the 'bioavailable' or 'toxic' fraction of aluminum in acidic surface waters. To achieve this research objective, the approach we selected was to: (1) determine the apparent binding affinity of fish gills for aluminum using a novel competitive toxicity bioassay technique with fish exposed to aluminum in the presence of organic acids of known aluminum binding affinity; and (2) modify the performance characteristics of existing cation exchange resins to match the apparent aluminum binding affinity of fish gills so that the total aluminum in a water sample could be separated into 'toxic' and 'nontoxic' fractions.