CES Soil Contamination & Remediation 2

Question 1

Which soil parameter most directly controls the bioavailability of heavy metals to plants?

Accepted Answer

Soil pH

Answer

Soil pH is the single most influential factor controlling heavy metal solubility and plant bioavailability, with most metals becoming more soluble and bioavailable under acidic conditions.

Question 2

Pump-and-treat systems for groundwater contamination are often criticized primarily because:

Accepted Answer

Contaminant rebound occurs after pumping ceases

Answer

Pump-and-treat systems frequently exhibit contaminant rebound, where concentrations rise back toward original levels when pumping stops, making complete aquifer restoration difficult.

Question 3

In the context of soil remediation, 'monitored natural attenuation' (MNA) relies on which of the following processes?

Accepted Answer

Natural physical, chemical, and biological processes to reduce contaminant concentrations

Answer

MNA relies on naturally occurring processes such as biodegradation, dispersion, dilution, sorption, and volatilization to achieve remediation goals without engineered intervention.

Question 4

What is the primary mechanism by which phytoremediation using hyperaccumulator plants removes metals from soil?

Accepted Answer

Plants translocate metals from roots to above-ground biomass which is then harvested

Answer

Hyperaccumulators translocate metals from roots through the xylem to shoots and leaves, and the metal-laden biomass is harvested and processed to remove the contaminant.

Question 5

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) established which key fund for hazardous waste site cleanup?

Accepted Answer

Superfund

Answer

CERCLA established the Hazardous Substance Superfund, commonly known as 'Superfund,' to finance cleanup of sites where responsible parties cannot be identified or are unable to pay.

(CES) Certified Environmental Scientist Practice Test

(CES) Certified Environmental Scientist Practice Test

CES Soil Contamination & Remediation 2