Synthetic Soil Matrix SSM Experiment

20% top soil and 5% gravel. The components were assembled, air dried, and mixed together. This Synthetic Soil Matrix sample was prepared to represent a typical eastern U.S. soil samples. 

The SSM sample was spiked with seven different heavy metals. The concentrations of each spike were followed arsenic - 500 mg/kg, cadmium-1000 mg/kg, chromium - 1500 mg/kg, copper - 9500 mg/kg, lead - 14,000 mg/kg, nickel - 1000 mg/kg, and zinc - 22,500 mg/kg. The concentrations used were based on the occurrence, frequency and concentration of contaminants commonly found in Superfund soils. 

The SSM samples were then adjusted so that their water content was approximately 30% by weight by adding distilled-deionized water. This was done to facilitate the reaction in the CHEMFIX process. This adjustment also allowed for better product handling capabilities. 

The optimization of CHEMFIX reagents on the hydrated samples was then conducted. Four samples of SSM were treated with varying ratios of reagents. The soil sample and reagents were thoroughly mixed and consolidated into one large lump artd allowed to cure for 48 hours. 

After curing, the Unconfined Compressive Strength (UCS) of the samples was measured by using a penetrometer. The reagent ratio that resulted in the desired UCS (1.5-2.5 tons/ft ) was utilized for further leach-ability testing. 

---