Please get out: PH homework Flip chart pages New page for homework Read da board!

Acid Rain How does it form? Where is this a problem? What does it do to ecosystems and people?

Acid Deposition formation: Secondary or primary pollutant Acid Deposition formation: Secondary or primary pollutant? Sources for precursors? Transportation? Wet or dry deposition? Practice diagram interpretation. Answer the questions in your quad based on the diagram. Be ready to explain what observation lead you to your inference. Answers: secondary – SOX from source, but “acid rain” from clouds after mixing in air Sources – trucks, factories – arrows point away Yes, transported – arrows suggest transportation Both wet and dry deposition (snow/particles vs. rain)

Formulas you need to memorize: SO3 + H2O  H2SO4 (sulfuric acid) NOx + H2O  2HNO3 (nitric acid) These are two forms (flavors) of acid deposition. Top is balanced. NOx formula is not balanced because it is a summary equation of many steps that students don’t need to know.

Acid rain < pH 5.6 THIS IS NOT ACID RAIN!!! Normal rain CO2 + H2O  H2CO3 (carbonic acid) Normal rain is always slightly acidic! THIS IS NOT ACID RAIN!!! THIS IS NOT POLLUTION!!!! Acid rain < pH 5.6 All rain is acidic, but not all rain is acid rain.

OBSERVATIONS. IS ACID RAIN A BIG PROBLEM IN HOUSTON OBSERVATIONS? IS ACID RAIN A BIG PROBLEM IN HOUSTON? WHERE IS ACID RAIN A BIG CONCERN?

Global acid rain areas of concern

Add a new page to your flip chart Second page – acid rain Draw the same atmosphere layers, sources, and“talkie bubbles” in blue or black Add precursors for acid rain in the bubbles in RED. Copy the two acid rain equations in the troposphere in RED. Which equation should you NOT add in?

Effects on terrestrial systems: Direct damage to leaves and roots Weak trees are susceptible to insects and disease

Acid deposition leaches nutrients from soil and makes toxins (Al3+) more soluble

Effects on Aquatic ecosystems Loss of biodiversity Range of tolerance Jelly-like fish eggs broken down Acidity denatures enzymes Acid shock – sudden increase in acidity, often in spring can cause fish kills Aluminum ions (Al3+) are released from lake bed, suffocating fish Below pH4.5, lakes devoid of fish

Cultural effects of acid rain Marble and limestone Acid breaks down these basic materials

Many famous buildings are being damaged Taj Mahal Parthenon

Statue of liberty Loss of artistic detail in Acropolis

Human health effects of acid rain Contributes to bronchitis and asthma

Acid Rain: Check for understanding! How does acid rain form? What is the pH of acid rain? Why is rain normally acidic? Why is this a bigger problem on the East Coast than here? Why is acid rain “like AIDS for plants”? Why are there more significant effects on aquatic systems than on terrestrial systems?

Make a classifying tree map

If you’re not part of the solution, you’re part of the precipitate. Solutions to Air pollution

1994 Map data from 1994. Next maps move forward in time. Make an observation about the change in trends.

1999

2007 Students should observe that acid rain is decreasing in how widely it’s spread and how severe the problem is. We’re getting better!

Two strategies Pollution prevention (don’t create the primary pollutants in the first place) Pollution clean up (now that they’re in the environment, let’s mitigate the effects) Mitigate means to make something less bad

Legal solutions Emissions trading policy (Cap and Trade): stationary pollution sources can buy, sell and trade the right to pollute. This policy ONLY exists in the US for SOx right now. (CO2 cap and trade just started in California last year!)

Technology Strategies: trap pollutants at the source These are all attached to a power plant or large factory at the smoke stack. Electrostatic precipitator – like your dryer that makes your socks staticky. The electrodes have a charge that particulates gather on. When there are too many particulates, they fall down. Collected particulates can be incorporated in cement. Baghouse filter – works like your vaccuum cleaner. Gases with particulates pass through fabric bags which trap particulates. Cyclone separator – like that spinny ride at the fair when you get pressed up against the wall and the floor drops out as you spin. Particulates up against wall accumulate and then drop down. Scrubber is only piece of material that removes SOX. Water contains powdered limestone (which is basic). As Sox and water move through, the acidity is neutralized. Remember Sox is removed with a Scrubber (the S’s go together)

Technology solution: improved vehicle efficiency Using less gas = fewer combustion pollutants Hybrids use friction from breaking to charge electric battery “regenerative breaking” Computer switches engine from gas to electricity.

Chevy Volt 2011 – pollution diverted to power plant

Technology solution: burn cleaner coal/coal gasification Burn low-sulfur coal from Western US Gasification turns solid coal to gas before it is burned – fewer particulates, SOx

“Liming” a lake (powdered limestone) This temporarily makes a lake less acidic

Stream doser Spot the pipe which adds the limestone solution to the stream!

I=PAT I = clean air P = growing A = options? T = options? Which of these can YOU do TODAY? 