Diseño de una Planta de Tratamiento de Aguas Residuales para la Central Ecuatorina de servicios agrícolas

Abstract

A wastewater treatment plant was designed for the Central Ecuatoriana de Servicios Agrícolas, located in Riobamba Canton, Province of Chimborazo. Through the experimental method, flow rates were determined during 7 days using volumetric methods; the design flow rate obtained was 3.26 L/min. For the physical, chemical and microbiological characterizations, samples were taken during 3 days using the composite method. The determinations of pH, temperature and nitrates: 7.92, 18.9 °C and 8.9 mg/L respectively are within the permissible limits; conductivity 1820 µSiems/cm, COD 1460 mg/L, BOD5 710 mg/L, phosphates 23. 1 mg/L, solids: dissolved 915 mg/L, settleable 44 mg/L, and suspended 1090 mg/L, oils and fats 730.6 mg/L, surfactants 6.80 mg/L, coliforms: fecal 2.6 X 105 CFU/100mL and total 1.2 X 106 CFU/100mL exceed the permissible limits of the TULAS. Concluding with the design in AUTOCAD software, the plant consists of: grids, oil and grease trap, septic tank, fafa, disinfection tank and drying threshing floor. Theoretical removal in the septic tank: oils and grease 96.30 mg/L, BOD5 256.90 mg/L, suspended solids 490 mg/L and in the fafa: BOD5 89.92 mg/L, COD 216.40 mg/L, suspended solids 196 mg/L. For the construction, a relatively flat site was found, with coordinates: 01°40'43?S. and 78°40'9?W. and a slope of 2755.351 masl to 2757.173 masl on the river banks and 2757.036 masl to 2758.251 masl at the site of interest. For the implementation of the plant it is recommended the unification of the existing flow and the use of the proposed operation and maintenance manual.