Unlocking circular potential in under-prioritized industries: Plant-by-plant industrial symbiosis plan in the light...

Global sustainability efforts have long focused on the heavy industries, overlooking the light and stone processing industries-despite their substantial solid waste generation and low value-added waste disposal methods. This study aims to develop a light-stone industrial symbiosis plan to unlock the circular potential of these under-prioritized industries. While industrial clustering offers potential for synergistic waste reutilization in the light and stone processing industries, practical implementation remains hindered by a long-standing data deficit. This study compiles a refined database covering 304 enterprises and eight key waste types (polyester waste, blended fabrics, bovine hair, trimming scraps, leather waste, footwear waste, crushed stone, and stone processing waste), and designs a plant-by-plant light-stone industrial symbiosis plan. By integrating high-resolution data with Material Flow Analysis, Life Cycle Assessment, and transport modeling, the proposed plan is validated, yielding three key findings: (1) The ten recycled products exhibit varying environmental contributions (0.7%-27.9%). This enables policymakers to prioritize key recycled products to formulate targeted symbiosis pathways based on local industrial structures, waste profiles, and key environmental concerns; (2) Inter-industry symbiosis drives 81.9% of waste reutilization gains, while intra-industry symbiosis delivers 92.3% of economic benefits. The greater environmental benefits of inter-industry symbiosis remain under-realized as firms favor high-profit intra-industry symbiosis, necessitating targeted policy interventions; (3) Light-stone symbiosis increases Fujian Province's solid waste reutilization rate by 16.9% with significant spatial disparities, requiring careful consideration of uneven potential gains and inter-city waste transport risks. This study provides a scalable template for advancing circular economy in similar under-prioritized industrial clusters worldwide.