||Evaluation of Mathematical Models for the Effects of pH and Temperature on Ammonia Toxicity to Aquatic Organisms.
Erickson, R. J. ;
||College of Saint Scholastica, Duluth, MN. Dept. of Chemistry.;Environmental Research Lab., Duluth, MN.
||EPA-R-809367 ;EPA-R-809240; EPA/600/J-85/527;
Water pollution ;
Marine microorganisms ;
Mathematical models ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Available data on the pH and temperature dependence of ammonia toxicity to aquatic organisms were examined and their agreement with various models was evaluated. A model which considers alteration of the relative concentration of un-ionized ammonia at the gill surface failed to adequately describe either pH or temperature dependence. A model that assumes that un-ionized ammonia and ammonium ion are jointly toxic was strongly supported by the data on pH dependence, but could not explain observed temperature dependence. Temperature dependence can be described empirically by a simple log-linear model. The effects of pH and temperature were generally found to be qualitatively and quantitatively similar among fish species. (Copyright (c) 1985 Pergamon Press Ltd.)