Diseño de un Sistema de Tratamiento de Aguas Residuales para la parroquia San Mateo del Cantón Esmeraldas.

Abstract

In order to prevent the Esmeraldas River to be contaminated we designed a Treatment Plant for sewage in San Mateo parish of Esmeraldas canton. As a first step the site survey was performed by observing how the waste water is discharged into the Esmeraldas River. Then we proceeded to perform flow rate measurements for seven days from 06h30 to 18h00, obtaining a flow capacity of 2.76 l / s. To perform this research work a composite sample was applied at three different times: 07h00, 12h00 and 18h00, obtaining a composite sample for physical-chemical and microbiological analysis, with the following results: Oils and fats 225 mg / L, Biochemical Oxygen Demand (BOD 5) 200 mg / L, Chemical Oxygen Demand 408 mg / 7, Phosphate 11 mg / L, suspended solids 192 mg / L, settling solids 1.6 mg / L, total solids 1682 mg / L Surfactants 1.7 mg7L, 56000 Fecal Coliform CFU / 100ml. These parameters exceed the permissible limits of environmental regulations of Unified Text of Secondary Environmental Legislation (UTSEL). With these parameters an appropriate treatment for sewage in San Mateo Parish was determined with the following components: a penstock, grids, an Imhoff tank, two subsurface wetlands using Eichornia Crassipes plant and finally filtration. With the design of the treatment plant these removal percentages were obtained: 90.5% BOD5, COD 94.1%, 89.7% phosphates, suspended solids 96,3%, 93.7% settleable solids, total solids 80.3 %, oils and fats 95.9%, 100% fecal coliform, turbidity 96.4%, and 76.5% Detergents, showing that the treatment used is reliable. The implementation of this treatment plant is recommended to the Parish Board of San Mateo, to avoid contamination of the river Esmeraldas by effluents discharged without treatment.