Optimizing resource efficiency in regional industrial symbiosis: Integrated modelling and scenario analysis
Bin Huang, Yan Zhuge, Rameez Rameezdeen, Ke Xing, Yue Liu
Abstract
In response to growing environmental concerns and global sustainability efforts, regional industrial symbiosis has emerged as a crucial strategy for enhancing resource efficiency and reducing the environmental impacts of production processes. The concrete industry, being resource-intensive with significant environmental footprints, represents a prime candidate for the application of such symbiotic approaches. By substituting general-purpose cement with treated alum sludge, a by-product of drinking water purification, the sludge-derived green concrete has the potential to markedly lower its embodied carbon. However, achieving widespread adoption necessitates a comprehensive evaluation of industrial symbiosis and logistic optimisation to ensure eco-economic viability. This study explores critical aspects of alum sludge treatment and develops a genetic algorithm (GA)-based tool to strengthen the symbiotic relationship between the water and concrete sectors, with a focus on decarbonizing sludge-derived concrete while maximising its economic returns. Eight scenarios were assessed, highlighting the environmental and economic advantages contributed by regional industrial symbiosis. Results show that pre-treating alum sludge at water treatment plants can lead to a carbon reduction of up to 86.24%, alongside potential energy and cost savings of approximately 65.16% and 52.04%, respectively. When factoring in landfill cost avoidance, total savings could exceed 100%. For sludge-derived concrete with a 10% cement substitution, energy savings and carbon reductions were recorded at 2.57% and 5.53%, respectively. Furthermore, the GA-based tool effectively identified optimal treatment locations or the nearest drinking water treatment plants based on market demand of sludge-derived concrete, thereby aligning environmental benefits with economic gains. Highlights : • Sludge-derived concrete promotes sustainability through reginal industrial symbiosis between water and concrete sectors. • An integrated model has been established to support the assessments of eco-economic performance and resource efficiency. • A GA-boosted framework has been developed to optimize eco-economic benefits of sludge-derived concrete production. • Scenario analysis conducted to explore decarbonization potential and cost-saving opportunities. • Supply chain optimization applied to enhance eco-economic viability within a regional industrial symbiosis framework.