Feasibility of Treating TPH-Contaminated Soils Using In-situ Solidification/Stabilization Techniques

摘要

In-situ remediation by Solidification and Stabilization (S/S) has shown huge promise in dealing with the clean up of soils contaminated with Volatile Organic Compounds (VOCs) and heavy metals, which are listed as Hazardous Substances under Recovery Act (RCRA). The site discussed in this paper was contaminated with BTEX, Naphthalene, heavy metals and other VOCs. In order to find a quick and effective solution it was decided to explore the possibility of using S/S for the in-situ remediation. Research being conducted includes exploring Type 1 Portland cement in combination with organo-clay. Portland cement was chosen as the binding material due to its advantages such as availability, previous experiences, costs and quality assurances. S/S has been found to be an effective method of remediation according to the various past and present Superfund projects. The study plan for this site involves bulk analysis and leachability tests to determine the initial level of contaminants in the soil and their potential leachability from the soil. During the treatability portion of the study, various proportions of the solidification/stabilization agent (Type 1 Portland cement and organo-clay) and contaminated soil would be mixed with water and allowed to set. The set samples would then be analyzed for leachability utilizing two leaching procedures. Set times, strength of end product, swell (volume change) and heat of hydration would also be measured. During mixing, volatilization of some of the lighter organic contaminants is expected. Mixing would be conducted in an air tight glove box and air samples will be collected from it. These air samples would then be analyzed by Gas Chromatography (GC) to determine the types and amounts of VOC’s emitted during the solidification process.