enviro

water table

• depth at which water should always be available

Aquifers

• rock or sediment that stores water

  • water still moves downhill

• Recharge zones: Areas where water infiltrates the ground to replenish aquifers.

• unconfined aquifers

  • usually is open at the top

  • water can infiltrate into the aquifer from the surface

• Confined aquifers: These are trapped between layers of impermeable rock or clay, which prevents water from easily entering or exiting the aquifer.

  • Might have different recharge areas

• Ogallala Aquifer

  • huge, old, aquifer in the N American prairie reagion

  • huge Impact on agriculture and human life in the surrounding states

Chapter 13: Water

Dynamic and Complex: The Global Water Cycle

• The global water cycle comprises various processes that facilitate water movement and storage.

• Key Processes:

  • Sublimation: Transition from solid to vapor.

  • Condensation: Vapor cooling to form liquid (clouds).

  • Precipitation: Rain or snow falling to Earth.

  • Evaporation: Liquid water turning into vapor.

  • Transpiration: Water released from plants into the atmosphere.

  • Infiltration: Water soaking into the ground.

  • Snowmelt Runoff: Water from melted snow flowing into streams.

  • Surface Runoff: Water flowing over land into rivers and lakes.

  • Groundwater Storage and Discharge: The storage of water underground and its eventual return to surface water.

Where is Earth's Water?

• Distribution of Earth's Water:

  • Freshwater: 2.5%

    • Groundwater: 30.1%

    • Glaciers and ice caps: 68.7%

    • Surface freshwater: 1.2%

    • Lakes: 20.9%

    • Rivers: 0.49%

    • Swamps and marshes: 2.6%

  • Saltwater: 97.5%

    • Oceans hold the majority of saltwater (1,365,000,000 km³).

Water Storage Mechanisms

• Infiltration and Aquifers:

  • Water accumulates underground in cracks and pores of soil and rock, referred to as aquifers.

  • The water table indicates the upper level of groundwater, which can be unconfined or confined by impermeable layers.

Pumped Well Systems

• Types of Aquifers:

  • Unconfined Aquifer: Directly available to recharge from the surface.

  • Confined Aquifer: Isolate from surface influence by a confining layer.

  • Recharge areas: Areas where water seeps into aquifers, ensuring the sustainability of groundwater.

  • Water withdrawals can be measured over time to monitor aquifer health.

Aquifers and Wells

• Definition and Types of Wells:

  • Flowing Artesian Well: Water rises to the surface due to pressure in confined aquifers.

  • Water Table Well: Taps into unconfined aquifers; water level fluctuates with the water table.

  • Extensive networks of aquifers used in the U.S.; Ogallala Aquifer is significant.

Sources of Water

• Types:

  • Surface Water: Lakes, streams, rivers.

  • Groundwater: Wells, aquifers, springs.

  • Water collected and stored in reservoirs for future use.

Water Use Across Sectors

• Global Water Consumption:

  • Largest Use: 70% for agriculture.

  • Industry: 20% of freshwater is used in manufacturing and processing.

  • Domestic Use: Approximately 10%.

  • Examples:

    • 4,650 liters of water to produce 300g of meat.

    • 4,100 liters to produce a cotton T-shirt.

Water Treatment Processes

• Key Components of Water Treatment:

  • Preliminary Treatment: Screening and sedimentation to remove large debris.

  • Coagulation and Flocculation: Chemicals added to form larger particles that trap contaminants.

  • Filtration: Sand and granular media filter out smaller particles.

  • Disinfection: Treatments such as chlorination and UV to make water safe for drinking.

Desalination Process (Tampa Bay Example)

• Processes to remove salt from seawater include:

  • Initial Particle Settlement: Heavier solids removed by gravity.

  • Filtration Methods: Sand filters and diatomaceous earth filters eliminate microscopic materials.

  • Reverse Osmosis: High-pressure pumps push water through semipermeable membranes to remove salt.

  • Post Treatment: Blending the desalinated water with treated surface water before distribution.

Regional Water Projects

• California Water Project: Complex system of reservoirs and aqueducts to supply water across regions.

• Significant infrastructures like dams and aqueducts play crucial roles in managing water supplies efficiently.

Maple Syrup Unit

• xylem

  • system of tubes that transports water to leaves up from the roots.

• Phloem

  • system of tubes that transports dissolved biomolecules (sugar) up and down plants.

  • “tap” or drill into phloem tubes to get sap

Water treatment

• Drinking water/ Municipal water

  • steps/general

    • large screens and filters

      • remove the large materials “fish” trees/branches, weeds, human materials

    • Pre-disinfection

      • chlorine, UV light, or ozone to kill the bacteria

    • Coagulation and flocculation

      • bind with biomolecules microorganisms/ to form “clumps”

      • coagulants in the water are mixed

      • remove the floc

    • Post Chlorination

      • chlorine added to kill bacteria/microorganisms in pipes between the water treatment plant and taps

Damns and Reservoirs

• Generate electricity (hydroelectric)

• water storage/control

• flood control

• negatives

  • destroys or alter habitat

  • flood

Water Pollution Overview

• Water pollution refers to contaminating water bodies such as lakes, rivers, oceans, and groundwater. This contamination can be caused by various pollutants from both point and non-point sources.

• Anything that degrades or reduces the quality of the water

Point vs Non-point Source Pollution

• Non-point Source Pollution:

  • Originates from diffuse sources; hard to trace.

  • Includes surface water runoff containing oils, fertilizers, chemicals, etc.

• Point Source Pollution:

  • Comes from a single identifiable source.

  • Common sources: factories, sewage treatment plants.

Major Sources of Water Pollution

Point Sources

• Industrial Facilities:

  • Mines and oil fields

  • Untreated sewage and wastewater effluent

  • Construction sites

  • Sewage treatment plants

Non-point Sources

• Agriculture and Irrigation:

  • Runoff from fertilizers and sediments

• Urban Areas:

  • Contributions from roads, streets, and unsewered areas

• Others:

  • Abandoned mines, acid deposition, runoff of chemicals

Common Water Pollutants

• Types of Pollutants:

  • Petroleum hydrocarbons, plastics, heavy metals (lead, mercury)

  • Sewage, radioactive waste, thermal effluents, detergents

  • Chemical spills (PCBs, benzene)

  • Food processing wastes (fats, grease)

  • Invasive species

  • Heat

  • Sediments

Effects of Major Water Pollutants

Categories and Examples

• Infectious agents:

  • Cause diseases (e.g., bacteria, viruses)

• Oxygen-demanding wastes:

  • Deplete dissolved oxygen, harming aquatic life.

• Plant nutrients:

  • Promote excessive algal growth.

• Organic chemicals:

  • Introduce toxins to aquatic ecosystems.

• Inorganic chemicals:

  • Introduce toxins (e.g., acids, salts, metals)

• Sediments:

  • Affect photosynthesis and food webs.

• Thermal pollution:

  • Makes species vulnerable to diseases.

Eutrophication Process

• Definition:

  • Natural process of nutrient accumulation in lakes over time.

• Cultural Eutrophication:

  • Human-induced acceleration of nutrient additions.

• Stages of Lake Eutrophication:

  • Oligotrophic:

  • Low nutrients, clear water; examples include Lake Tahoe.

  • Mesotrophic:

  • Moderate nutrient levels.

  • Eutrophic:

  • High nutrients; typically murky water; examples include many shallow lakes.

Cultural Eutrophication Sources

• Discharge of untreated sewage

• Nitrogen from automobile emissions

• Detergents containing phosphates

• Agricultural runoff (nitrates, phosphates)

• Inorganic fertilizers

• Erosion from poor land use practices

Microplastic Pollution

• Summary:

  • Microplastics are pervasive; can accumulate in the food chain, affecting marine life and human health through consumption.

Biomagnification

• Concept:

  • Toxins like methylmercury accumulate in organisms through the food chain, increasing in concentration at higher trophic levels.

• Example:

  • Phytoplankton absorb PCBs, which are then eaten by zooplankton, and further up the food chain to larger fish, mammals, and ultimately humans.

Conclusion

• Water pollution is an intricate problem arising from both natural and anthropogenic activities. Understanding the sources, types, and impacts of pollutants is essential for effective water management.

Types of Water Pollution

• Biological Pollution

  • Infectious Disease (Pathogens): Microorganisms that cause diseases in humans and aquatic life.

  • Oxygen-Demanding Waste: Organic matter that can deplete oxygen in water bodies, affecting aquatic ecosystems.

• Chemical Pollution

  • Nutrients (Fertilizers): Excessive nitrogen and phosphorus leading to eutrophication.

  • Toxic Inorganic Materials: Contaminants like heavy metals (e.g., mercury, lead).

  • Persistent Organic Pollutants (POPs): Chemical substances resistant to environmental degradation.

• Physical Pollution

  • Sediments: Particulate matter that can block sunlight.

  • Thermal Pollution: Discharge of heated water from industrial processes.

  • Solid Waste: Improper waste management affects ecosystems and water quality.

What are POPs?

• Definition: Persistent Organic Pollutants are chemicals that resist environmental breakdown. They bioaccumulate in the food chain and affect human health.

• Examples:

  • Pesticides: DDT

  • Industrial Pollutants: PCBs (Polychlorinated Biphenyls)

  • By-products of industrial processes: Dioxins and Furans

• Global Risk: POPs can be transported across borders, leading to environmental and health risks worldwide, even in remote areas like the Arctic.

More on POPs

• Persistence: Many POPs can remain unchanged in the environment for decades due to resistance to natural breakdown processes.

• Toxicity and Bioaccumulation: Highly toxic, they accumulate in fatty tissues of living organisms, posing serious health risks.

Dirty Dozen Chemicals - Names and Structures

• List of Chemicals:

  • Aldrin, Dieldrin, Endrin

  • Chlordane, Heptachlor

  • HCB, PCBs, DDT

  • Mirex, Toxaphene, PCDFs, PCDDs

• Notes: Most are chemical pesticides and herbicides.

PFAS Names and Structures

• Common PFAS

  • PFBA: Perfluorobutanoic acid

  • PFBS: Perfluorobutane sulfonic acid

  • PFOA: Perfluorooctanoic acid

  • PFOS: Perfluorooctane sulfonic acid

• Uses of PFAS:

  • Firefighting foam

  • Non-stick cookware

  • Stain and water-resistant coatings for clothing and furniture

  • Food packaging, paints, varnishes, sealants

Oxygen-Demanding Wastes

• Components: Organic waste that can be decomposed by aerobic bacteria.

• Examples: Sewage, waste from food processing plants, and animal feedlots.

• Effects: High Biological Oxygen Demand (BOD) from decomposition can lead to low levels of Dissolved Oxygen (DO), harming aquatic organisms.

Eutrophication

• Nutrients: Nitrogen and phosphorus from runoff increase phytoplankton growth, causing algae blooms.

• Consequences:

  • Sediments block sunlight needed for aquatic plants.

  • Decomposition of algae consumes Oxygen, leading to habitats with depleted oxygen (hypoxic conditions).

Oxygen Sag Curve

• Description: The relationship between waste discharge and aquatic life health.

• Zones:

  • Clean Zone: High DO, low BOD

  • Decomposition Zone: Increased BOD and decreased DO due to waste decomposition

  • Septic Zone: Very low DO, high pollution, minimal biodiversity

  • Recovery Zone: Improvement in water quality as waste decreases

• Importance: It illustrates the effects of pollution on freshwater biodiversity.

How the Dead Zone Forms

• Process:

  1. Freshwater runoff from rivers creates a barrier in saltwater, limiting oxygen contact.

  2. Algae blooms from nutrient overload die and decompose, further depleting oxygen.

  3. Result: Creation of oxygen-depleted areas, known as "dead zones", where aquatic life is severely limited.

Runoff, Sewage, and Eutrophication

• Cycle:

  • Runoff introduces nutrients, leading to algal blooms.

  • Decay of algae leads to oxygen consumption, causing low DO in bottom waters.

  • Loss of biodiversity and ecosystem stability.

Bioaccumulation and Biomagnification

• Bioaccumulation: Increase in pollutant concentration in an organism over its lifetime.

• Biomagnification: The increase in concentration as the pollutant moves up the food chain.

• Example: Mercury from coal plants accumulating in aquatic food chains, affecting top predators such as sharks and tuna.

Groundwater Pollution "Plume"

• Terminology:

  • Dissolved Contamination: Pollutants dissolved in groundwater.

  • Floating Free Product: Layer of contaminants floating on the water table.

  • Product Smear Zone: Area where contaminants adsorb on soils.

• Impact: Spreads underground, posing risks to drinking water sources.

Air pollution

Earth’s Atmosphere Overview

• The Earth’s atmosphere is divided into layers based on temperature and altitude.

  • Ionosphere - Starts above 90 km, minimal pressure (0.0001% of sea-level pressure).

  • Thermosphere - High temperatures, but low density.

  • Mesopause - Transition zone between mesosphere and thermosphere.

  • Mesosphere - Characterized by decreasing temperatures with altitude.

  • Stratopause - Transition zone between the stratosphere and mesosphere.

  • Stratosphere - Contains the ozone layer which absorbs UV radiation.

  • Troposphere - Closest to Earth's surface; weather phenomena occur here.

  • Mount Everest peak is 8.85 km, where atmospheric pressure is about 28% of sea-level.

Summary of Air Pollutants

• Key pollutants and their sources/effects:

  • Carbon Dioxide (CO₂):

  • Cause: Combustion of fossil fuels and respiration.

  • Effect: Contributes to the greenhouse effect.

  • Nitric Oxides (NO):

  • Cause: High-temperature combustion in vehicles and power plants.

  • Effect: Contributes to acid rain and smog.

  • Carbon Monoxide (CO):

  • Cause: Incomplete combustion of organic materials.

  • Effect: Reduces blood’s oxygen-carrying capacity.

  • Sulfur Dioxide (SO₂):

  • Cause: Burning of coal and oil; volcanic activity.

  • Effect: Contributes to acid rain.

  • Particulates (PM):

  • Cause: Combustion, industrial activities, and natural sources (like wind).

  • Effect: Causes respiratory illness and deposits as soot.

Primary and Secondary Pollutants

• Primary Pollutants: Directly emitted into the atmosphere.

  • Examples include CO, NO, SO₂.

• Secondary Pollutants: Formed through chemical reactions in the atmosphere.

  • Examples include NO₂, HNO₃, O₃, and particulates like PANS.

Types of Smog

Industrial Smog

• Created by burning sulfur-rich coal or oil.

  • Produces sulfur dioxide (SO₂) and sopuric acid (H₂SO₄).

• The emissions can lead to health problems and environmental degradation.

Photochemical Smog

• Results from reactions between nitric oxide (NO), hydrocarbons, and sunlight.

  • Produces ozone (O₃) and other secondary pollutants.

  • Common in urban areas, especially with high traffic.

Natural and Industrial Sources of Pollution

• Natural Sources:

  • Oceanic (sea salt, sulfate from phytoplankton), volcanism, wildfires.

• Industrial Sources:

  • Power plants, factories, and transportation (cars, trucks).

Acid Rain Formation

• Occurs when sulfur dioxide (SO₂) and nitrogen oxides (NO₂) react in the atmosphere.

• The reaction with water vapor produces sulfuric acid (H₂SO₄) and nitric acid (HNO₃).

• Acid rain can lead to ecological damage and deteriorate buildings.

Electricity Generation and Pollution Control

• Understanding coal plants and nuclear power plants and their components is crucial.

• Industrial plants need to implement pollution control technologies to mitigate emissions.

• Examples of technologies include scrubbers and precipitators to capture particulate matter.

Mercury in the Food Chain

• Methylmercury accumulation in aquatic food chains poses health risks to wildlife and humans.

• Guidance on mercury levels advises limited consumption of certain fish species, particularly for vulnerable populations.

Conclusion

• Awareness and understanding of air pollution sources, their effects, and methods for mitigation are essential for environmental science and public health.

• Continuous monitoring and legislation are needed to improve air quality and protect ecosystems.