CPWM Waste Treatment Technologies and Disposal Methods 4

Question 1

Which chemical stabilization agent is most commonly used in solidification/stabilization (S/S) treatment of heavy metal-contaminated waste?

Accepted Answer

Portland cement

Answer

Portland cement is the most widely used binder in S/S treatment because it immobilizes heavy metals through precipitation and physical encapsulation.

Question 2

In rotary kiln incineration of hazardous waste, the secondary combustion chamber primarily serves to:

Accepted Answer

Ensure complete combustion of organics by providing additional residence time at high temperature

Answer

The secondary combustion chamber provides additional high-temperature residence time to destroy unburned organic gases escaping the primary kiln.

Question 3

What is the purpose of 'intermediate cover' in landfill operations compared to 'daily cover'?

Accepted Answer

Intermediate cover uses thicker compacted soil to seal areas inactive for more than 30 days

Answer

Intermediate cover is a thicker soil layer (typically 12 inches) applied to areas that will be inactive for 30 days or more, providing additional protection compared to daily cover.

Question 4

Wet scrubbers in waste incinerators are used primarily to remove:

Accepted Answer

Acid gases such as hydrogen chloride and sulfur dioxide

Answer

Wet scrubbers contact flue gas with an alkaline liquid solution to neutralize and remove acid gases like HCl and SO₂.

Question 5

Which waste disposal method is specifically prohibited for listed hazardous wastes under the EPA Land Disposal Restrictions (LDR) program unless treatment standards are met?

Accepted Answer

Placement in any land disposal unit

Answer

LDR prohibits land disposal of untreated listed hazardous waste; wastes must meet specific treatment standards (Best Demonstrated Available Technology) before land placement.

(CPWM) Certified Professional in Waste Management Practice Test

(CPWM) Certified Professional in Waste Management Practice Test

CPWM Waste Treatment Technologies and Disposal Methods 4