Document Type : Research article
Authors
1
Master's student in Environmental Pollution, Faculty of Agricultural, Water, Food, and Functional Products, Science and Research Branch, Islamic Azad University, Tehran, Iran.
2
Professor, Department of Environmental Science, Faculty of Agricultural, Water, Food, and Functional Products, Science and Research Branch, Islamic Azad University, Tehran, Iran.
3
Assistant Professor, Department of Environmental Science, Faculty of Agricultural, Water, Food, and Functional Products, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Abstract
Background and Objective: Rapid socio-economic development has significantly increased municipal solid waste (MSW) generation. Several urban waste management strategies have been analyzed to address environmental impacts and evaluate energy-based sustainability. This study evaluates emergy-derived Environmental Yield Ratio (EYR) and net emergy across different waste treatment methods.
Materials and Methods: A descriptive-analytical approach was applied. Emergy values for each input were calculated by converting physical quantities (mass, energy, monetary units) into standard emergy units using appropriate transformity factors. Stored emergy was also estimated. Emergy-based indicators were then derived to assess resource investment efficiency and potential for emergy recovery among waste management options.
Results: Composting demonstrated Karaj's highest net emergy efficiency among the evaluated strategies. Emergy investment per gram of MSW was calculated as follows: sanitary landfill (6.51 × 10⁶ sej/g), incineration (4.61 × 10⁶ sej/g), and composting (8.06 × 10⁵ sej/g). EYR and net emergy values confirm composting as the most environmentally favorable alternative.
Conclusion: Emergy analysis indicates a direct relationship between higher EYR and increased net emergy. Composting outperforms sanitary landfilling in environmental performance, offering the most sustainable urban waste management solution for Karaj.
Open Access Policy: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/
Keywords