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Abstract
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There are standard techniques to remove and stabilize petroleum-contaminated soils to prevent or minimize the release of contaminants into the environment. Carbon dioxide (CO2), an air pollutant, is an important heat-trapping (greenhouse) gas that causes global warming. In this paper, utilization of CO2-induced magnesite minerals in remediation and stabilization of diesel-contaminated sandy soil were evaluated in laboratory-scale experiments. Indeed, this study has two environmental advantages, one reduction of CO2 emission and petroleum removal from soil environment. Soil specimens containing contamination of about 5% and 10% of diesel contents were prepared. The magnesium carbonate hydrate (Nesquehonite) was produced by a CO2-induced process and added to contaminated samples in 10, 15, and 20% plus 2.5% Portland cement. The UCS, permeability, TPH, and SEM tests were conducted on the pieces. The Portland cement increased the compressive strength of contaminated samples while it was found a reduction of total petroleum hydrocarbons (TPH) by about 29%. Maximum diesel removal efficiency was obtained at treated samples with 20% magnesium carbonate and 2.5% cement, about 90% reduction. SEM images of treated soil samples indicated that the higher absorption capacity of magnesium carbonate was related to needle/blade shape particles.
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