Abstract:

Industrial solid wastes, such as steel slag, blast furnace slag (BFS), and gasified fly ash, possess inherent reactive properties that can be utilized for detoxifying hazardous waste, thereby facilitating waste remediation through waste-derived solutions. In this study we selected a range of materials, including BFS-based cementitious materials, aluminate cement, BFS-clinker-vitamin C composites, red mud-coal gangue geopolymers, and steel slag-gasified fly ash geopolymers, to develop a life cycle model dedicated to the solidification/stabilization (S/S) of municipal solid waste incineration (MSWI) fly ash. Results indicate that: 1)the primary environmental impact of solid waste-based S/S technologies is on human health, with industrial chemical inputs being the main contributors. 2) Among the various activation methods examined, mechanochemical activation exhibited the least environmental impact. However, the environmental impact of geopolymer systems, particularly due to the extensive use of alkaline activators, was found to be the most significant. 3) In contrast, the BFS-clinker-vitamin C S/S method demonstrated the lowest environmental impact. Therefore, optimizing activation methods for solid waste-based materials and reducing the use of activators and additives are crucial to minimizing toxicological risks to human health.

Key words: municipal solid waste incineration fly ash, industrial solid waste, solidification/stabilization, activation, life cycle assessment