Remediation & Mitigation Strategies Flashcards

Which soil vapor extraction (SVE) design parameter most directly controls the radius of influence at a contaminated site?

Answer: Soil permeability and applied vacuum

Soil permeability and the applied vacuum together determine how far the pressure gradient extends, defining the SVE radius of influence.

In a bioventing system for petroleum hydrocarbon remediation, the primary goal of air injection is to:

Answer: Supply oxygen to stimulate indigenous aerobic microorganisms

Bioventing delivers oxygen to the vadose zone to enhance aerobic biodegradation of hydrocarbons by native bacteria.

A permeable reactive barrier (PRB) using zero-valent iron (ZVI) remediates chlorinated solvents primarily through:

Answer: Reductive dechlorination via electron donation

ZVI donates electrons to chlorinated ethenes, sequentially removing chlorine atoms through reductive dechlorination.

When designing an air pollution control system, the pressure drop across a fabric filter (baghouse) is primarily important because it affects:

Answer: Fan energy consumption and filtration velocity

Pressure drop determines the energy required to move air through the system and governs actual filtration velocity (air-to-cloth ratio).

Which in situ chemical oxidation (ISCO) reagent is most appropriate when treating a site with high natural organic matter (NOM) content?

Answer: Persulfate activated with heat or alkali

Persulfate, particularly when thermally or alkaline-activated, is less quenched by NOM than permanganate or Fenton's reagent and is preferred at high-NOM sites.

A wet scrubber's removal efficiency for gaseous pollutants is governed primarily by which parameter?

Answer: Liquid-to-gas ratio and mass transfer coefficient

Gas-phase absorption efficiency depends on how much liquid contacts the gas (L/G ratio) and the ease of transfer between phases (mass transfer coefficient).

During natural attenuation monitoring for a BTEX plume, which field parameter most directly indicates active aerobic biodegradation?

Answer: Decreasing dissolved oxygen near the contaminant source

Dissolved oxygen depletion near the source zone indicates it is being consumed by aerobic microorganisms degrading BTEX compounds.