**1. Introduction**

Waste managemen<sup>t</sup> in emerging countries has become urgen<sup>t</sup> during recent years, because economic growth and rise of consumption have caused a rise in waste production. The escalation of generation of residues has resulted in a shortage of disposal sites and higher waste managemen<sup>t</sup> costs. In Accra, Ghana, the expenditure for municipal solid waste (MSW), for example, increased from 2013 to 2015 by 8% [1]. Other important waste managemen<sup>t</sup> issues which developing countries must face include lack of proper governance instruments, inefficient resource use, overdependence on imported equipment, improper financing methods and application of technology, inequality in service stipulation, and deficient technical expertise [2]. In many cases, especially in lower-income countries, governance issues play a more important role than technical aspects [3]. Therefore, it is vital to find implementable, knowledge-based solutions for the governments of countries with poor municipal waste managemen<sup>t</sup> performance. For example, in Mexico City, which produces 12,920 Mg per day of MSW and experiences the problem of shortage of landfill capacity, the waste infrastructure requires an alternative scenario. However, with the variety of technologies for treatment, recovery, and energy generation from waste, it is hard for decision makers, not experts themselves, to make a correct choice. Diverse technologies have distinctive climate change effects, and different investment and operation costs. An overall assessment of a waste managemen<sup>t</sup> system is needed in such cases. This assessment should combine aspects such as environmental performance, economic viability, and social acceptability. Also, local conditions should always be a consideration before a system is implemented.

Extensive research has been done to determine sustainable decision-making models to assess waste managemen<sup>t</sup> scenarios. Among the existing models, the most popular ones are life-cycle assessment (LCA), cost–benefit analysis, and multicriteria analysis. LCA calculates the environmental impact of all processes of the waste treatment from "cradle to grave"; cost–benefit analysis considers the monetary dimension, while multicriteria decision analysis (MCDA) compares social, economic, and environmental criteria [4]. There is literature available which compares different waste managemen<sup>t</sup> systems in emerging and developing countries. Brunner and Fellner [5] conducted a study to determine appropriate waste managemen<sup>t</sup> systems in less-developed economies. Zubruegg [6] developed an assessment tool based on a questionnaire. Elsaid and Aghezzaf [7] presented a progress-indicator-based assessment guide for integrated municipal solid waste managemen<sup>t</sup> systems.

MCDA is often used in waste management. One of the MCDA methods widely applied in waste managemen<sup>t</sup> is ELECTRE (Elimination and Choice Expressing the Reality). ELECTRE can incorporate many evaluation criteria for selecting an optimal alternative, coupled with the possibility of involving several decision-makers. It has been applied to the real choice process of a solid waste managemen<sup>t</sup> system in Bosnia and Herzegovina by Vuˇcijak et al. [8]. Another, PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations), was developed by Brans [9] and further extended by Brans and Vincke [10]. Queiruga et al. [11] used PROMETHEE, combined with a survey of experts, to rank Spanish municipalities for the installation of Waste Electrical and Electronic Equipment (WEEE) recycling plants. Demesouka et al. [12] used a combination of geographical information systems (GIS) and MCDA methods in the analysis of municipal solid waste landfill suitability.

In this study, the alternative scenarios of MSW managemen<sup>t</sup> in Mexico City are compared based on MCDA. The purpose of the analysis is to determine the most sustainable scenario for the city. The method used was chosen because it allows the involvement of environmental, economic, and social criteria, by comparing diverse quantitative and qualitative dimensions to produce a ranking. Moreover, it allows the participation of different stakeholders with various interests. Therefore, it has been chosen as a tool to assess the sustainability of waste managemen<sup>t</sup> in this work.

The goal of this study is to find the most sustainable waste managemen<sup>t</sup> scenario for Mexico City based on waste composition, experts' opinions, and overall assessment of state-of-the-art technologies, by using MCDA. No research combining economic, environmental, and social dimensions has been previously conducted to determine a sustainable residues managemen<sup>t</sup> model for Mexico City. This study is the first to visualize and compare the economic benefits, the impact of waste treatments on the environment, and social benefits of specific waste technologies for Mexico City. The outcome should help decision makers in the introduction of a successful, sustainable waste managemen<sup>t</sup> system. The results are assumed to be transferable to other megacities in emerging countries and help decision makers in the selection of waste managemen<sup>t</sup> scenarios with energy and resource recovery.
