Influence of algae on amitrole and atrazine residues in water

Removal of [14C]amitrole (3-amino-s-triazole) from water by three algae was more complete at pH 7.5 or above than at lower pH levels. [14C]atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) removal was affected little by pH. Absorption of [14C]amitrole steadily increased over 24 h, whereas [14C]atrazine removal reached equilibrium by 6 h. [14C]amitrole removal by Scenedesmus quadricauda was directly related to herbicide concentration while [14C]atrazine removal was inhibited by increasing concentrations. Optimum light and temperature for algal growth favored [14C]amitrole uptake. [14C]atrazine removal was unaffected by either darkness or low temperature. [14C]atrazine was not metabolized by Scenedesmus and apparent photosynthesis was inhibited in the four algae. Growth of algae was prevented by 1 ppm by weight atrazine. [14C|amitrole was readily metabolized by Scenedesmus. Three 14C metabolites were extracted from cells while four chromatographically different 14C metabolites occurred in the...