Tag Archives: biomass burning

AE6: Neutralising Threat of Acid Rain

1.Mammoth Cave National Park in Kentucky is in close proximity to the coal-fired electric utility plants in the Ohio Valley. Noting this, the National Parks Conservation Association (NPCA) reported that this national park had the poorest visibility of any in the country.

a) What is the connection between coal-fired plants and poor visibility? 

Coal-fired plants produce sulfur dioxide, creating sulfate particles which is the culprit for 60-85% of poor visibility in the eastern parks.

b) The NPCA reported “the average rainfall in the Mammoth Cave National Park is 10 times more acidic than natural.” From this information and that in your text, estimate the pH of rainfall in the park.

The estimated pH of rainfall in the park is pH 4-5, because normal rain has a pH of 5-6. If rainfall in this park is 10 times more acidic, the range should be around pH 4-5.

 

2. Here are examples of what an individual might do to reduce acid rain. For each, explain the connection to producing acid rain.

a. Hang your laundry to dry it

Hanging laundry uses natural sunlight and wind to dry the clothes, whereas a clothes dryer requires electricity, which uses energy produced by power plants to dry the clothes. By avoiding the use of clothes dryer, we reduce the use of electricity and thus reduce the need to produce more energy through power plants (reduce burning of coals, reducing SO3 emissions).

b. walk, bike, or take public transportation to work

All of these options reduces acid rain production because they require less to zero amount of gasoline and has little to no emissions that contribute to acid rain production.

c. Avoid running dishwashers and washing machines with small loads.

Using larger loads reduce the energy per unit load in dishwashers and washing machines. This requires less energy to wash the same amount of items, so power companies don’t have to produce as much electricity by coal burning which emits SO3.

d. Add additional insulation on hot water heater and pipes

Additional insulation means less heat loss from the hot water heater and pipes, so the need to produce electricity to generate heat is lessened, reducing SO3 emissions.

e. Buy locally grown produce and locally produced food.

Buying locally grown produce and locally produced food reduce the use of gasoline which is needed in food transportation. This reduction in gasoline use results in less gas emissions that contribute to acidity of rain.

 

3.
a) Gives names and chemical formulas for five acids and five bases.

ACIDS: hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), sulfurous acid(H2SO3) and phosphoric acid (H3PO4).

BASES: potassium hydroxide (KOH),  sodium hydroxide (NaOH), ammonium hydroxide (NH4OH), magnesium hydroxide (Mg(OH)2) and calcium hydroxide (Ca(OH)2).

b) Name three observable properties generally associated with acids and bases.

Generally, acids turns blue litmus paper red, corrodes metals, and release carbon dioxide from a carbonate. On the other hand, bases turn red litmus paper blue, have a soapy/slippery feel in water, and are caustic to skin.

 

4. The concerns of acid rain vary across the globe. Many countries in the North America and Europe have websites dealing with acid rain. Either search to locate one (“Canada, acid rain”) or use these links to websites in Canada, the UK, or Europe. What are the issues in Singapore? Does the acid deposition originate outside or inside the Singapore’s borders?

From August to October 1993, the Indonesian forest fires that happened released large amounts of gaseous and particulate pollutants into the atmosphere. The emissions of particulates formed a plume that was visible by satellite and affected regional air quality in Southeast Asia significantly. This prolonged haze saga allowed us to examine the effects of biomass burning on regional atmospheric chemistry. A comprehensive study was done to assess the influence of biomass burning impacted air masses on precipitation chemistry in Singapore. 104 rain samples were collected and went through an automated wet-only sampler from July through December 1997, determining many major organic and inorganic ions. Mean pH values ranged from 3.79-6.20 with volume-weighted mean of 4.35. Many of the rain samples had elevated concentrations of these ions during the biomass burning period. The relatively high concentrations of sulfate, nitrate, and ammonium ions observed during the biomass burning period are due to the long residence time of air masses. This leads to gas progressively turning into particles of biomass burning emission components. The decrease in pH of precipitation in response to the increased concentrations of acids is only marginal. This is credited to the neutralization of acidity by ammonia and calcium carbonate.