Buffering By Soils From Sulfate Adsorption

Question 0

Sulfate adsorption capacity (SAC):

Answer 0

The capacity of a soil to retain or release the sulfate anion SO4 2-

Question 1

Some soils have the capacity to

Answer 1

Absorb anions, such as sulfate ion SO4 2-

Question 2

SAC: Occurs through

Answer 2

Electrostatic attraction or complexation.

Question 3

Through electrostatic attraction:

Answer 3

Sulfate ions are attracted to the hydroxyl groups of clays with positive pH-dependent charges, such as aluminium or iron hydroxides.

Question 4

Complexation:

Answer 4

The sulfate may form strong chemical bonds with the hydroxyl groups. The anions cannot exchange as easily with the ions in solution, unlike the anions held through simple electrostatic attraction.

Question 5

As the SAC is saturated, the

Answer 5

Rate of transport of the sulfate ion through the soil will increase.

Question 6

The acidity of the water leaving a soil is therefore dependent on the

Answer 6

Amount of acid deposition on the soil.

Question 7

Soils with a large CEC and SAC have a large capacity to

Answer 7

Neutralise acid deposition.

These soil properties are determined by the material forming the soils.