Evaluating comprehensive carbon emissions of solidification/stabilization technologies: A case study

Considering the overexploitation of resources and environmental consequences, sustainable management and resourceful utilization of different waste materials are of great research interest globally. Among different strategies, cement-based stabilization/solidification (S/S) technology has been recently considered as a highly efficient technique. Considering the limited studies on environmental impacts, the carbon emissions of recently developed S/S technologies for sustainable three hazardous wastes materials, viz. contaminated marine sediment (CS), municipal solid waste incineration fly ash (MIFA), and concrete slurry waste (CSW), were evaluated by using the life cycle assessment (LCA) technique. For comparative analysis, a number of scenarios under different strategies for CS and MIFA S/S technologies, and several scenarios of CSW utilizations were developed. Based on the LCA results, the most sustainable scenarios for the studied waste materials were identified along with their contribution analysis for future potential improvement. For instance, the use of alternative binders, including the supplementary cementitious materials instead of ordinary Portland cement, and other recycled materials including recycled aggregates can significantly reduce the carbon emissions for both CS and MIFA. However, the utilization of fresh CSW for producing concrete partition wall blocks reduces carbon emission significantly. The results can help the selection of low-carbon strategies and scenarios for practical application of resourceful utilization and management of the studied waste materials.