Evaluación de la planta de tratamiento de aguas residuales de la Ciudad de Marcabelí en la Provincia de El Oro.

Abstract

The present thesis paper aims to carry out the evaluation of the WWTP of the city of Marcabelí, to verify if the effluent of the same meets the parameters of discharge to the receiving body, established in Annex 1 of Book VI of TULSMA Texto unificado de Legislación Secundaria del Ministerio del Ambiente, process that was carried out by means of the hydraulic evaluation of its treatment units and the characterization of its waters, for this purpose physico-chemical and microbiological analyses of the waste water were carried out in the following parameters pH, Total Solids, BOD5, COD, Total Nitrogen, Ammoniacal Nitrogen and Fecal Coliforms. All this through MSV Laboratory Food, Water and Soil Analysis of Cuenca city, a laboratory accredited by the Ecuadorian Accreditation Service-SAE. For the complete characterisation of the waste water, four samples were taken at the entry and exit points of the plant and at the exit of the treatment units of the septic tank and anaerobic filter, necessary to assess compliance with discharge parameters and pollutant removal efficiency in treatment units. Samples were also taken in the receiving body, upstream and downstream, to measure the pollution produced by the discharge of waste water to the Marcabelí River. Hydraulic evaluation of septic tank and anaerobic filter treatment units showed that their current volume will not be able to address future demands at the end of the design period. The results of the analysis of the sewage at the outlet of the septic tank and anaerobic filter showed that the units have a moderate removal efficiency in some parameters, In some cases there was no removal but an increase in pollutants. The analyses carried out in the effluent of the plant showed that the parameters BOD5, Total Nitrogen and Fecal Coliforms, do not comply with the allowable discharge limit as established in the current environmental regulations, this is due in large part, the non-recurrent maintenance of the treatment units, the short retention time available to the filtration units and the fact that the process of ozone disinfection of the effluent is not being carried out, leading to contamination of the receiving body. Faced with these problems, the expansion of the treatment plant through the construction of two additional units of septic tank and three anaerobic filter, necessary to meet future demands and to meet the recommended retention times, the commissioning of the ozonification equipment is also necessary for the disinfection of the effluent and for the regular maintenance of the units in accordance with the times laid down in the plant operation and maintenance manual, all this in view of the need to extend the service life of the WWTP until the end of the design period in 2035.