Which remediation technology is most effective for removing high concentrations of low-solubility petroleum compounds from containment soil?

Which remediation technology is most effective for removing high concentrations of low-solubility petroleum compounds from containment soil?

• A. Pump and Treat Wells
• B. Injection of Bacteria Cultures
• C. Soil Vapor Extraction Wells
• D. Soil Wash With a Weak Sulfuric Acid/Water Mixture

Answer: (C)

When contaminants in soil are volatile and have low solubility in water, removing them as vapors from the soil air is most effective. Soil Vapor Extraction uses vacuum to pull air through the unsaturated zone, drawing volatile petroleum compounds out of the soil as a vapor and into an off-gas treatment system. This directly targets the contaminant in the soil gas phase, so high concentrations in containment soil are reduced quickly. Why this approach fits best here: low-solubility hydrocarbons don’t dissolve well in water, so methods that rely on dissolving or biodegrading them in groundwater or soil water are slower and less effective. Pushing groundwater or waiting for biodegradation won’t address the vapor-phase contaminants in the vadose zone as efficiently, and a chemical wash like an acid rinse is not appropriate for petroleum hydrocarbons and could introduce other problems. Soil Vapor Extraction specifically focuses on removing the contaminant in its vapor form from the soil, making it the most suitable option for high concentrations of low-solubility petroleum compounds in containment soil.

When contaminants in soil are volatile and have low solubility in water, removing them as vapors from the soil air is most effective. Soil Vapor Extraction uses vacuum to pull air through the unsaturated zone, drawing volatile petroleum compounds out of the soil as a vapor and into an off-gas treatment system. This directly targets the contaminant in the soil gas phase, so high concentrations in containment soil are reduced quickly.

Why this approach fits best here: low-solubility hydrocarbons don’t dissolve well in water, so methods that rely on dissolving or biodegrading them in groundwater or soil water are slower and less effective. Pushing groundwater or waiting for biodegradation won’t address the vapor-phase contaminants in the vadose zone as efficiently, and a chemical wash like an acid rinse is not appropriate for petroleum hydrocarbons and could introduce other problems. Soil Vapor Extraction specifically focuses on removing the contaminant in its vapor form from the soil, making it the most suitable option for high concentrations of low-solubility petroleum compounds in containment soil.