Environmental, economic, and social sustainability assessment: A case of using contaminated tailings stabilized by waste-based geopolymer as road base

Abstract

Contaminated tailings, e.g., iron tailings, could be stabilized by low-carbon geopolymers for recycling as road base, but the sustainability has yet to be evaluated comprehensively. This study developed a sustainable framework from the life cycle perspective, consisting of quantitative indicators in environment, society, and economy, to assess five stabilization cases (i.e., M1, M2, C1, C2, and cement). Moreover, a modified AHP (Analytic Hierarchy Process)-CRITIC (CRiteria Importance Through Inter-criteria Correlation)-TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) model was applied to select the most sustainable stabilization method. The sustainability scores of four cases using geopolymers were higher than that of the cement case (0.22), with C2 (0.75), C1 (0.64), M1 (0.56), and M2 (0.54), respectively. Sensitivity analysis confirmed that the assessment results were relatively stable, especially when the subjective weight of the economy was not the highest (the cement counterpart had economic advantages). This study constituted a novel approach to complement the selection of sustainable stabilization cases, bridging the gap of focusing exclusively on green stabilization performance.