Engineering Properties of Heavy Metal Contaminated Soil Solidified/Stabilized with High Calcium Fly Ash and Soda Residue
Both high-calcium fly ash and soda residue are the industrial by-products generated during the combustion of coal for energy production and sodium carbonate production, respectively. Previous studies suggested that both high-calcium fly ash and soda residue can be used to treat heavy metal contaminated soils. Therefore, a series of laboratory experiments were performed to investigate the strength and leaching properties of Pb-contaminated soils solidified/stabilized by high calcium fly ash and soda residue. The results presented that adding high-calcium fly ash to the contaminated soils can significantly improve the soil strength and reduce the Pb2+ amount released out. The specimens treated with soda residue got a higher strength, but a relatively lower chemical stability than that of fly ash. SEM results confirmed that Ca(OH)2 and CSH was the main products that improved the engineering properties of the stabilized contaminated soils.
KeywordsFly ash Soda residue Heavy metal contaminated soil Solidification/stabilization Unconfined compressive strength Leaching characteristics
This research is financially supported by the National Natural Science Foundation of China (grant nos. 41672306, 41372281, 41172273, and 41572282).
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