Evaluación y rediseño integral de la planta de tratamiento de aguas residuales de la comunidad Tutupali Grande, Cuenca, Ecuador

Abstract

Wastewater constitutes the liquid fraction of waste produced by every community. It can be defined as the combination of liquid waste originating both from residences and from industries, institutions, businesses, etc., and infiltration, surface and rainwater. The decomposition of the organic matter contained in the wastewater, if it is discharged without treatment to the receiving bodies, represents a potential danger for the various consumptive uses of water for the human being and for the environment. Therefore, a correct collection, conduction, treatment, and final disposal is necessary. ETAPA EP, a municipal institution that manages environmental sanitation in the Cuenca canton, currently manages 27 treatment plants in rural areas, including the Tutupali Grande system. This plan, which is located in the Tarqui parish, south of Cuenca, was built in 2013 with the aim of treating liquid waste from this community. The Tutupali Grande wastewater treatment plant consists of a flow diverter, a septic tank, and an up-flow anaerobic filter. The septic tank performs the primary treatment and the filter the secondary treatment. The lack of preliminary and tertiary treatment units, and the current configuration of existing units are, among other, the causes of low treatment efficiency. In addition, inconveniences have been detected in the handling of sludge as a result of the periodic maintenance carried out at the plant, due to the fact that the plant is located in a place that is difficult to access to for the vehicles that transport the sludge to the Pichacay sanitary landfill in the city of Cuenca, located more than 30km from the plant. The general objective of this work is to study and propose sustainable solutions for the wastewater treatment in rural areas of the Cuenca canton, specifically in the community of Tutupali, through the evaluation of the state of the units and the purification processes, the analysis of design alternatives for the treatment train with a focus on environmental and economic sustainability, the proposal of a sustainable solution for the management of the system´s residual sludge and the design of all the treatment units. The methodology used in this work follows the scientific guidelines, for which, after observation and data collection, the following hypothesis is established: the current configuration of the elements that make up the system causes a deficient wastewater process, and therefore, an effluent that does not meet the required quality parameters. The result of this work is a proposal for a complete redesign of the plant.