An investigation was conducted of the environmental fate of diethyl phthalate (DEP) in the continuous-flow channel microcosms housed in the USEPA's Environmental Research Laboratory, Athens, GA. The objectives of the investigations were to determine (1) whether a definable stable state could be achieved, (2) the effects of different nutrient treatments on ecosystem structure and function and on the fate of DEP, and (3) the degree of similarity between replicate microcosms. Aufwuchs assemblages in the microcosms reached fairly stable levels of biomass, metabolic activity, and similar species composition within 2 or 3 months after inoculation. Communities receiving direct nutrient inputs appeared to stabilize first, followed by downstream communities. A highly significant relationship between phosphorus inputs and aufwuchs chlorophyll a was established suggesting that the relatively stable input concentrations of inorganic nutrients into any given compartment were among the primary factors controlling maximum development of aufwuchs.

Caption title. Distributed to depository libraries in microfiche. At head of title: Project summary. "November 1982." "EPA-600/3-82-093." "PB83-136341"