Diseño del sistema depurador de la Urbanización Vista al Parque, kilómetro 8.5 vía Guayaquil-Samborondón

Abstract

In the "Vista al Parque" residential area, there is an anaerobic digester (septic tank) that functions as a wastewater treatment plant (WWTP) for the current population of 592 inhabitants. This system has been in operation for more than two decades, but due to a lack of maintenance, it has deteriorated to the point where the quality of the treated water is compromised, causing environmental impacts. The project's objective is to redesign the WWTP using technical and sustainable criteria to improve the well-being of the residents, enhance the quality of effluent discharge, and ensure compliance with regulations. Fieldwork and laboratory analyses were conducted to assess the current plant, revealing treated water characteristics with BOD₅ and COD levels of 432 mg/L and 1,098 mg/L, respectively exceeding the maximum permissible limits (MPL) of 100 mg/L and 200 mg/L. While the analysis suggested that the plant's capacity could be adequate, its operations and treatment processes fail to meet MPL due to solids accumulation and the lack of proper operation and maintenance. A complete redesign of the plant was proposed, as the current facilities are too deteriorated to be reused. The redesigned system will include efficient pretreatment with screening and grit removal, a primary sedimentation tank, a Membrane Bioreactor (MBR) system, and a high-rate sedimentation tank. The new design will achieve 99% pollutant load removal compared to the current 60% treatment efficiency. The reference budget for the construction phase is USD 128,282.04 + VAT, while the operational phase will cost USD 24,165.34 + VAT annually. This translates to a cost of USD 216.69 + VAT per inhabitant for CAPEX and USD 40.82 + VAT per inhabitant annually for OPEX. Keywords: Treatment, MBR, redesign, pollutant load.