Sostenibilidad del Nexus Agua-Energía en Sistemas de Tratamiento de Efluentes Agroindustriales

Abstract

Abstract: this thesis develops a methodological framework in order to drive improved sustainability assessment of agro-industrial wastewater treatment systems (ai-WWTs), committed to energy recovery, particularly those using biological units in their processes schema. This methodology would provide improved understanding about pathways to foster biological ai-WWTs as alternative bioenergy sources in low-income regions, where the economic/environmental potential of biogas or sludge produced from ai-WWTs is particularly depleted, because of stressed technological drawbacks and the lack of harmonized energy and environmental policies focused on expanding the involvement of ai-WWTs as sustainable energy-producing processes. Consequently, smart strategies are required to promote the sustainable exploitation of this kind of alternative energy. This methodology is based on the following principles: (i) To considerer ai-WWTs as multi-function systems; (ii) To assess the control pollution and energy functions of the ai-WWTs by means of the Life Cycle Assessment (LCA) and Net Environmental Benefits Indicators (NEB), in order to stress the importance of implementing improved ai-WWTs to achieve higher energy recovery goals in this activity; (iii) to state a concise number of principles-criteria of sustainability (PCS) for ai-WWTs and (iv) to use a cost-emergy approach to assess the co-benefit behind ai-WWTS recovering energy. The methodology introduces a set of Sustainable Development Indicators (SDIs) to fulfil the PCS previously defined. SDIs are expressed as eco-efficiency ratios, specifically tailored to account the effect of the energy recovery in ai-WWTs and the co-benefits related to mitigation or control of relevant environmental impacts evaluated by LCA. The “economic term” deals with the improvement on some environmental pressure indicators related to ecosystem services, carbon capture and shift of conventional energy sources and their costing has been done on the basis of “emergy cost” methods. A proof of concept of this methodology has been done on two study cases in Colombia (poultry and beverage) showing that the NEB approach is a key aspect to prove additionality when ai-WWTs are small-limited energy sources. Furthermore, that integration of LCA and emergy methods has allowed building representative, local and global SDIs for ai-WWTs enabling to identify environmental and economic characteristics of ai-WWT as alternative energy sources

Date of Award	8 Apr 2017
Original language	Spanish (Colombia)
Awarding Institution	Universidad Nacional de Colombia-UNAL Doctorado en Ingeniería - Sistemas Energéticos
Supervisor	Angela Adriana Ruiz Colorado (Supervisor)