Environmental Chemistry Unit Review

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Questions and Answers

What is a primary function of secure landfills?

To prevent pollution outside the facility (correct)

To promote anaerobic biodegradation

To store hazardous waste safely

To eliminate the production of methane gas

What is produced when hydrocarbons are burned?

Hydrogen sulfide and sulfur dioxides

Carbon dioxide and water vapor (correct)

Methane and water vapor

Ozone and nitrogen oxides

Which compounds are present in natural gas?

Methane and hydrogen sulfide only

Methane, ethane, propane, and butane (correct)

Methane, propane, and sulfur dioxides

Only carbon dioxide and water vapor

What occurs when hydrogen sulfide is removed from sour gas?

Sulfur dioxide is produced Signup and view all the answers

Which of the following is NOT a pollutant produced from industrial processes?

Methane Signup and view all the answers

What is the primary goal of wastewater treatment?

To return water to the environment with minimal pollutants Signup and view all the answers

Which treatment process involves bacteria decomposing organic matter?

Secondary Treatment Signup and view all the answers

What material is primarily removed during the primary treatment of wastewater?

Large solids and sediments Signup and view all the answers

What role do septic tanks play in rural waste management?

They trap grease and large solids for local soil breakdown Signup and view all the answers

What is a significant feature of sanitary landfills?

They use clay liners to prevent leachate from contaminating groundwater Signup and view all the answers

During which treatment phase are biosolids typically removed from water?

Secondary Treatment Signup and view all the answers

Where does domestic waste primarily originate from?

Household kitchens, bathrooms, and laundries Signup and view all the answers

What treatment method is used to remove phosphates and nitrates from water?

Tertiary Treatment Signup and view all the answers

What is the pH of normal rain or snow?

5.6 Signup and view all the answers

What process describes the dramatic lowering of water pH due to accumulated acidic deposits melting in spring?

Spring Acid Shock Signup and view all the answers

Which of the following compounds is NOT considered a component of acid rain?

NaCl (Sodium Chloride) Signup and view all the answers

What is the function of scrubbers in controlling acid effects?

To neutralize acidic compounds with limestone Signup and view all the answers

What role do catalytic converters play in vehicle emissions control?

Facilitating complete combustion to reduce harmful gases Signup and view all the answers

Which property is characteristic of acids?

Taste sour Signup and view all the answers

What does the pH scale primarily measure?

The acidity or basicity of a solution Signup and view all the answers

Which of the following is a characteristic of bases?

Produces a slippery feel Signup and view all the answers

What is created as a result of the neutralization reaction between an acid and a base?

Salt and water Signup and view all the answers

Which indicator is commonly used to determine pH levels?

Bromothymol Blue Signup and view all the answers

What environmental phenomenon results from the combination of rainwater and atmospheric chemicals?

Acid rain Signup and view all the answers

What is the approximate pH of neutral substances on the pH scale?

7 Signup and view all the answers

Which of the following statements about acids is NOT true?

Acids have a pH greater than 7. Signup and view all the answers

Which type of molecule primarily serves as an energy source for metabolism?

Carbohydrates Signup and view all the answers

What defines macronutrients in the context of biological molecules?

Essential nutrients required in large amounts Signup and view all the answers

Which of the following compounds is classified as a lipid?

Vegetable oil Signup and view all the answers

Which statement about proteins is correct?

Proteins are primarily used for structural support and chemical reactions. Signup and view all the answers

What is the main role of nucleic acids in biological systems?

Building blocks of DNA Signup and view all the answers

What are trace elements required for in living organisms?

Maintaining enzyme function Signup and view all the answers

Which group of substances is referred to as macrominerals?

Minerals required in large quantities Signup and view all the answers

What distinguishes organic molecules from inorganic ones?

Predominantly composed of carbon and hydrogen Signup and view all the answers

What is the primary distinction between point source and non-point source pollution?

Point source pollution can be easily traced back to its origin. Signup and view all the answers

How does an increase in pH levels affect aquatic organisms?

It decreases the diversity of all organisms. Signup and view all the answers

Which of the following factors can contribute to the concentration of pollution in aquatic environments?

Accumulation of agricultural runoff nutrients. Signup and view all the answers

What does dilution of pollution mean?

Pollution becomes less concentrated over time. Signup and view all the answers

Which of the following is a chemical factor that affects water quality?

Heavy metals present in the water. Signup and view all the answers

What are biological indicators used for in water quality assessment?

To determine water quality through living organisms Signup and view all the answers

Which of the following organisms indicates good quality water due to their need for high oxygen levels?

Caddisflies Signup and view all the answers

What does a parts per million (ppm) measurement indicate in environmental science?

One unit of an element per one million units of an overall solution Signup and view all the answers

Which factor does NOT influence the levels of dissolved oxygen in water?

The pH level of the water Signup and view all the answers

Which type of organisms are considered microbiological indicators of water quality?

Bacteria Signup and view all the answers

Which of the following substances is best characterized as a solute in a water solution?

Salt Signup and view all the answers

What is a significant consequence of low levels of dissolved oxygen in water?

Decline in fish populations Signup and view all the answers

How is the concentration of pollutants often reported in environmental studies?

As a parts per million (ppm) or parts per billion (ppb) Signup and view all the answers

What is the concentration of sulfuric acid in parts per million (ppm) after a 50 L drum spills into a lake containing 30,000 L of water?

1663 ppm Signup and view all the answers

If a student adds 70 mL of pee to a 1000 L pool, what is the resulting concentration in ppm?

70 ppm Signup and view all the answers

What is the concentration of free chlorine in ppm if a 20 mL sample contains 0.5 mL of chlorine?

25,000 ppm Signup and view all the answers

What does LD50 represent in toxicity studies?

Lethal dose for 50% of test subjects Signup and view all the answers

With an LD50 of 0.27 mg/kg for rat poison, will a 0.50 mg dose likely kill a rat weighing 0.85 kg?

Yes, it exceeds the safe limit Signup and view all the answers

What consequence can arise from mixing different pesticides in water systems?

Formation of deadly chemical combinations Signup and view all the answers

What term describes substances that can cause severe health issues or fatalities?

Toxins Signup and view all the answers

What is primarily responsible for breaking down most modern pesticides after one growing season?

Bacterial action Signup and view all the answers

What is the maximum dosage of arsenic that can be given to a 1.75 kg duck to reach its LD50?

22.75 mg Signup and view all the answers

If a 55 kg person ingests 9625 mg of caffeine, what would this caffeine dosage cause?

Half the population would possibly die. Signup and view all the answers

What is the LD50 of arsenic in mg/kg?

13 mg/kg Signup and view all the answers

How many cans of Monster Energy Drink would it take to reach a lethal dose for a 55 kg person, consuming one can containing 300 mg of caffeine each?

32 cans Signup and view all the answers

What are the potential side effects of consuming over 400 mg of caffeine daily?

Unpleasant side effects like jitteriness and insomnia Signup and view all the answers

What does the LD50 value represent?

The amount of poison needed to kill half of the population. Signup and view all the answers

What can complicate the interpretation of toxicity tests conducted on animals?

Different effects in animals vs humans Signup and view all the answers

What is the appropriate LD50 range for caffeine in mg/kg?

150-200 mg/kg Signup and view all the answers

Study Notes

Wastewater Treatment Overview

Wastewater treatment aims to return used water to the environment with minimal pollutants.
This involves several stages including primary, secondary, and tertiary treatment.
Primary treatment physically separates large solids and sediments.
Secondary treatment involves bacteria decomposing organic matter.
Tertiary treatment removes phosphates and nitrates to meet discharge standards, often using percolation through plant beds or UV light.

Sources of Wastewater Nitrogen

A study suggests that wastewater adds 6.2 million tonnes of nitrogen to coastal waters globally.
Leading polluters include China (1,890 thousand tonnes), India (659 thousand tonnes), and the United States (358 thousand tonnes).
Major sources include a lack of proper toilet facilities, septic tanks, and inadequate sewer systems.
Wastewater nitrogen sources include household wastes like toilets, sinks, showers, and other household wastewater.

Nutrients in Wastewater

Wastewater contains significant amounts of nitrogen, phosphorus, and potassium, enough to offset over 13% of global agricultural fertilizer demand.
Potential revenue from recovering these nutrients is estimated at US$13.6 billion annually.
Nitrogen, phosphorus, and potassium levels in wastewater are significant in teragrams. Wastewater contains these nutrients in teragrams.

Stormwater vs. Wastewater

Stormwater runoff from streets and other surfaces is collected separately from wastewater from sinks and toilets.
Stormwater is routed to different channels and basins and is not treated before flowing into water sources.
Wastewater is treated before releasing into water bodies to prevent pollution and meet discharge standards.

Sanitary Landfills

Sanitary landfills are used for household and industrial waste disposal, usually compacted, and covered with earth, and sometimes clay.
Leachate collection pipes and liners keep contaminants from contaminating groundwater.
Methane gas byproducts are managed to prevent release into the atmosphere. The gas is often recovered for use.

Secure Landfills

Secure landfills are for hazardous waste disposal in land, designed, constructed, and operated to prevent pollution outside the facility.
Hazardous waste is contained using liners and collection systems to prevent contaminants from entering groundwater.

Fuel Combustion

Burning hydrocarbons (e.g., coal, oil, natural gas) releases carbon dioxide, water vapor, sulfur dioxide, nitrogen oxides, mercury, and lead into the atmosphere.
These emissions contribute to environmental issues like acid rain and air pollution.

Industrial Processes

Industrial processes, such as electrical energy generation, mineral processing, and fertilizer production, release harmful chemicals, such as sulfur oxides and nitrogen oxides into the air. These processes also release compounds like methane, ethane, propane, and butane.
Natural gas (containing hydrogen sulfide, H2S, "sour gas") requires treatment to remove H2S, generating sulfur dioxide.

Other Considerations

Septic tanks (rural areas) are large underground containers that trap grease and solids. Liquid waste is distributed through pipes into a gravel drainage area, preventing groundwater contamination.
Bacteria and microorganisms help decompose organic waste in sewage and septic systems.
Wastewater treatment plants use biological and chemical processes to remove pollutants (e.g., lime, biological treatment methods like activated sludge).

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Description

Test your knowledge of environmental science with this quiz that covers topics such as secure landfills, hydrocarbon combustion, and natural gas components. Answer questions related to pollutants and gas treatment processes in an industrial context.