"12020 EXG 03/72." Includes bibliographical references.

Fourteen industrial organic chemicals were examined for their persistence through biological treatment, either as the initial compounds, or as degradation products. Semi-continuous activated sludge systems were employed. The ability of each of the chemicals to participate in reactions with free chlorine was then determined in a series of batch experiments. Certain of the test compounds formed persistent degradation products during treatment. Five of the initial compounds reacted readily with chlorine, under conditions commonly employed in effluent chlorination. Five of the chlorination products were further studied in respirometer experiments to evaluate their persistence in mixed microbial systems. Their toxicity to fish was determined using the static bioassay procedure. A series of bench scale, continuous flow ecosystems were established for the evaluation of longer term effects of three of the chlorination products. Several varieties of organisms, representing different levels in the food chain, were studied.