Presenting the model of urban waste management with circular economy approach

Introduction: The rapid growth of population, unsustainable consumption patterns, and accelerated urbanization have led to a significant increase in municipal solid waste (MSW) generation, creating severe environmental and public health challenges worldwide. International reports indicate that the annual volume of waste is growing rapidly, with countries such as Iran—where per capita waste generation exceeds the global average and most waste is disposed of through non-hygienic landfilling—facing even greater risks. Inefficient waste management not only threatens ecosystems and human health but also imposes considerable economic costs. In this context, the circular economy paradigm, emphasizing reduction, reuse, and recycling, has emerged as a promising solution for minimizing waste and enhancing resource efficiency. By redefining production and consumption cycles, this model provides a pathway for cities to reduce waste, improve environmental sustainability, and create added value. Accordingly, the present study aims to develop a conceptual framework for urban waste management in Iran based on the principles of the circular economy.

Methodology: This study is applied in nature and adopts a mixed-method approach (qualitative–quantitative) to combine theoretical insights with empirical evidence. First, a systematic literature review was conducted to identify indicators related to urban waste management and the circular economy, which served as the theoretical foundation. Subsequently, the fuzzy Delphi method, implemented in two rounds, was employed to screen and prioritize the indicators, offering a robust mechanism to manage uncertainty in expert judgments. The expert panel consisted of 12 specialists in waste management, environmental studies, the circular economy, and urban planning, selected based on criteria such as postgraduate education, relevant professional experience, and subject-matter expertise. This diversity ensured that managerial, economic, environmental, and technological dimensions were adequately addressed. Furthermore, to ensure the validity of prior studies and strengthen the conceptual framework, the CASP tool was applied as a qualitative evaluation method to assess the rigor, clarity, and applicability of the reviewed literature.

Findings: studies, 35 initial indicators of urban waste management based on the circular economy approach were identified. During the first round of the fuzzy Delphi process with 12 experts, four additional indicators were proposed, raising the total to 39 indicators. While the initial level of consensus among experts was moderate, the second round achieved a much higher level of agreement, and ultimately, 20 key indicators were validated as the final set. These validated indicators were structured into a three-layer conceptual framework: (1) institutional and infrastructural indicators, (2) operational and quantitative indicators, and (3) outcome-oriented and feedback indicators. Additionally, the indicators were thematically grouped into five major categories: waste generation, infrastructural and technical, economic and financial, recycling performance and circular economy implementation, and social and policy-related dimensions. This dual structure (three-layer and five-category) provides conceptual clarity and comprehensiveness, enabling a systematic analysis of urban waste management and offering a practical framework to support

Discussion and Conclusion: economy approach by identifying and validating 20 key indicators through the fuzzy Delphi method and expert consensus. These indicators were structured across five main domains—waste generation and composition, infrastructural and technical, economic and financial, recycling performance and circular economy implementation, and social and policy-related dimensions—and organized into three conceptual layers (institutional-structural, operational-quantitative, and outcome-feedback). Such a dual classification provides a comprehensive and systematic tool for multi-dimensional analysis. The findings highlight that the proposed framework, while aligned with global trends, is tailored to the local context of Iran and offers a practical instrument for municipalities and policymakers to assess performance, prioritize corrective actions, and design sustainable development strategies. Compared with prior studies, this model is innovative in its three-layer and five-category structure and in its application of the fuzzy Delphi approach to extract localized indicators. Practical applications of the model include the development of key performance indicators (KPIs), continuous monitoring and evaluation systems, optimization of incentive policies, public engagement, and private sector investment. In the long term, adopting this framework can facilitate the creation of evidence-based, measurable, and adaptive systems that enhance environmental efficiency, reduce final landfill disposal, and promote more sustainable patterns of resource management. Future research can expand this mode this model toward predictive systems, decision-support tools, and practical implementations at local, national, and comparative.
Keywords: Municipal waste management, circular economy, fuzzy Delphi, performance indicators