Exam 3: Acid deposition

What are the main chemicals involved in acid rain and what are the sources of each of them?

Sulfur oxides: burning of sulfur in coal
Nitrogen oxides: transportations/auto emissions
Ammonia: Land application of animal wastes; feedlots; agricultural operations

Natural rainwater has a typical pH of ____? Acid rain has a pH of ____?

Rainwater: 5.6-5.7
Acid rain: <5.6

What are qualities that make a soil more resistant to acid rain?

Landscapes with thicker soils, greater amount of clays, large amounts of adsorbed cations

What effects did/does acid rain have on sugar maple and red spruce?

Red spruce: reduces tolerance of needles by 3-10 degree C because of leaching of calcium from the needles
Sugar Maple: impaired health due to lack of Ca and Mg - makes them susceptible to other stresses such as insect defoliators
Al in the soils can block the plant uptake of Ca

What are four ways in which reductions in SOx emissions were achieved after the Clean Air Act Amendments?

Low-sulfur coal
Scrubbers on smokestacks
Increased combustion efficiencies and new technology
Cap and trade policies

What is the main reason NOx emissions have not had as great of reductions as SOx?

NOx emissions come from a wide range of sources such as vehicles and factories making them harder to control. SOx comes from specifically the burning of fuels with sulfur.