Effects of coal liquid water-soluble fractions on growth and survival of four aquatic organisms

Abstract

Toxicities of water soluble fractions (WSF) derived from a fresh and a water-leached solvent-refined coal (SRC II) material were compared by observing freshwater organism response to chronic exposure. Concentrations, relative distributions, and loss over time of phenols and aromatic hydrocarbons differed between aqueous extracts derived from fresh and leached SRC II material. Readily water-soluble phenols predominated in initial WSFs; higher molecular weight compounds with relatively lower solubility predominated in leached WSFs. Suppression of growth, reproduction and survival of invertebrates,Chironomus tentans, Tanytarsus dissimilis, andDaphnia magna and the algaeSelenastrum capricornutum, were observed at concentrations ranging from 0.02 to 0.42% of WSFs derived from fresh SRC II liquid and 0.80 to 3.95% of WSFs derived from leached SRC II material. Alga populations were the least sensitive to WSFs generated from the coal liquid. Based on equal concentrations of carbon or phenols, solutions derived from leached SRC II liquids were usually more toxic to test species. Data suggest that tests of potential long-term effects of complex materials must be designed and interpreted on the basis of organism exposure to compounds most likely to persist in the environment.