Determinacion de la toxicidad por aluminio del efluente de la planta potabilizadora de el cebollar en el río Tomebamba, utilizando bioensayos ecotoxicológicos

Abstract

The use of aluminum sulfate as a coagulant, in the water purification process, allows the removal of suspended matter, facilitating subsequent filtration and sedimentation. As a result, sedimentation and filtration units, cleaning and maintenance need of generating wastes containing humic matter and aluminum. The resulting effluent water from treatment in plant maintenance El Cebollar of Cuenca, is poured directly into the Tomebamba River; hence the goal of this thesis was to evaluate residual levels of aluminum in said effluent, determining toxicity on the medium using ecotoxicological bioassays. Samples were taken in the discharge of effluent before discharge on Tomebamba River and in areas upstream and downstream of it. Aluminum concentrations were determined using ICP spectrophotometry. Bioassays were performed in ecotoxicological models Daphnia magna, Poeciliareticulata, Lactuca sativa, Phaseolus vulgaris and Zea mays, as the OECD protocols. Aluminum concentrations in the effluent and points upstream and downstream of the discharge, the flow of the effluent and the river were obtained; additional environmental toxicity in ecotoxicological models used, calculating the LC50, IC50, UT and ICOTOX indices. The results defined a degree of "highly toxic" effluent generated on Tomebamba River, although in winter time, the river has a good capacity to assimilate the effluent, whereas in times of low rainfall, the river loses this capacity, and no protection on the toxic effects generated.