Sistema de tratamiento de las aguas residuales de la ciudad de Alausí.

Abstract

This work deals on the physical chemical treatment, based on filtration and ozonization of Alausi city sewage, at the Chimborazo province South. Previously, the sewage flux was measured and pro jected to 2020 year near 16 L/s and the sewage was characterized on base of nine contamination parameters, such as solids (totals, suspended and dissolved), Biochemical Oxygen Demand of 5 days and 20 °C, Chemical Oxygen Demand, Nitrogen (total and organic ) and Coliforms (totals and fecals). According to the obtained data from the sampling design system and from the laboratories of the Etapa enterprise of Cuenca city, the Alausi sewage can be considered as middle strength. It was developed two series of exp eriments, batch about the sewage and continuous on the ozonized air current, with 2 and 3 minutes of detention times in a 16 liters effective volume reactor. The different parameters about removing efficiencies were appreciable highs; this is, for 3 minute s of detention time, such efficiencies were between 83 y 94 %, with the exception of total nitrogen (20 %) and organic nitrogen (70 %), because of the nitrate formation. For 2 minutes of detention time, the efficiencies averaged above 97 %, also with the exception of total nitrogen (71 %). As the BOD 5 balance, while sewage be not treated, the concentration of this parameter for the water river increase in a 67 %, but once treated, this value will be reduced down to 10 %. The Initial Environmental Revisio n yielded 17 % only from the totality of points possible to be obtained and the Environmental Impact Evaluation showed an environmental quality about 136 % better; this implies an estimated environmental benefit /cost relationship about 0,0026 percent unit s by each USD invested.