Remediation Technologies and Treatment Design
Domain scope
This domain tests technology screening, treatment design, and performance limiting factors for soil and groundwater remediation. Expect questions on SVE, bioremediation, in-situ chemical oxidation, stabilization, and pump-and-treat.
Core rules and concepts
- Screen technologies by contaminant type, depth, geology, moisture, and whether destruction, removal, or immobilization is intended.
- Soil vapor extraction works best for volatile contaminants in the unsaturated zone; air permeability and radius of influence control design.
- In-situ chemical oxidation (ISCO) requires stoichiometric oxidant plus natural oxidant demand (NOD).
- Bioremediation requires electron acceptors, nutrients, and favorable pH and temperature; reductive dechlorination needs anaerobic conditions.
- Stabilization immobilizes metals but does not destroy them; long-term leaching must be tested.
Worked example
For 1 kg of trichloroethene (TCE), stoichiometry is about 2 mol KMnO4 per mol TCE, or 2.4 kg KMnO4/kg TCE. If soil NOD is 5 g/kg for 1,000 kg soil, NOD = 5 kg. Total KMnO4 = 2.4 + 5 = 7.4 kg before applying an efficiency factor.
Traps that cost marks
Applying SVE below the water table; ignoring NOD; assuming stabilization destroys contamination; and neglecting rebound after treatment.