Raven Water Pollution PPT.ppt

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Overview of Chapter 17

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Types of Water Pollution

• SewageSewage

• Disease-causing agentsDisease-causing agents • Sediment pollutionSediment pollution

• Inorganic plant and algal nutrientsInorganic plant and algal nutrients • Organic compoundsOrganic compounds

• Inorganic chemicalsInorganic chemicals • Thermal pollutionThermal pollution

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Water Quality Today

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Improving Water Quality

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Types of Water Pollution

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Water pollution

• Any physical or chemical change in water that Any physical or chemical change in water that

adversely affects the health of humans and adversely affects the health of humans and

other organisms other organisms

• Varies in magnitude by locationVaries in magnitude by location

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Major water pollution issue globally

• Lack of disease-free waterLack of disease-free water

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Eight categories

• Sewage, disease-causing agents, sediment Sewage, disease-causing agents, sediment

pollution, inorganic plant and algal nutrients, pollution, inorganic plant and algal nutrients,

organic compounds, inorganic chemicals, organic compounds, inorganic chemicals,

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Sewage

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The release of wastewater from drains or

sewers

• Includes human wastes, soaps, and detergents Includes human wastes, soaps, and detergents

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Causes 2 serious environmental problems:

• EnrichmentEnrichment

• Fertilization of a body of water by high levels of Fertilization of a body of water by high levels of

plant and algal nutrients (nitrogen and phosphorus) plant and algal nutrients (nitrogen and phosphorus)

• Increase in Biological Oxygen Demand (BOD)Increase in Biological Oxygen Demand (BOD)

• Amount of oxygen needed by microorganisms to Amount of oxygen needed by microorganisms to

decompose biological wastes decompose biological wastes

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Sewage

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Sewage- Eutrophication

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Oligotrophic

• Unenriched, clear water that supports small Unenriched, clear water that supports small

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Sewage- Eutrophication

o Eutrophic-

Eutrophic-• Slow-flowing stream, lake or estuary enriched by Slow-flowing stream, lake or estuary enriched by

inorganic plant and algal nutrients such as phosphorus inorganic plant and algal nutrients such as phosphorus

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Disease-causing Agents

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Infectious organisms

that cause diseases

• Originate in the wastes Originate in the wastes

of infected individuals of infected individuals

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Common bacterial or

viral diseases:

• Typhoid, cholera, Typhoid, cholera,

bacterial dysentery, bacterial dysentery, polio, and infectious polio, and infectious

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Disease-causing Agents

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Monitored by testing for presence of E.

coli in the water via a

fecal coliform test

_{fecal coliform test}

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Sediment Pollution

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Excessive amounts of suspended soil

particles

• Originates from erosion of agricultural lands, Originates from erosion of agricultural lands,

forest soils exposed by logging, degraded forest soils exposed by logging, degraded

stream banks, overgrazed rangelands, strip stream banks, overgrazed rangelands, strip

mines, and construction mines, and construction

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Problems

• Limits light penetrationLimits light penetration

• Covers aquatic animals and plantsCovers aquatic animals and plants

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Inorganic Plant and Algal Nutrients

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Chemicals such as nitrogen and phosphorus

that stimulate the growth of plants and

algae

• Harmful in large concentrationsHarmful in large concentrations

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Sources:

• Human and animal wastes, plant residues, Human and animal wastes, plant residues,

atmospheric deposition, and fertilizer runoff atmospheric deposition, and fertilizer runoff

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Causes:

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Inorganic Plant and Algal Nutrient-

The Dead Zone

Every Spring, fertilizer runoff from farms and manure from feedlots

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Organic Compounds

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Chemicals that contain carbon atoms

• Natural examples: sugars, amino acids, and oils Natural examples: sugars, amino acids, and oils • Human-made examples: pesticides, solvents, Human-made examples: pesticides, solvents,

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Inorganic Chemicals

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Contaminants that contain elements other

than carbon

• Examples: acids, salts, and heavy metals Examples: acids, salts, and heavy metals

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Do not degrade easily

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Lead

• Found in old paint, industrial pollutants, leaded Found in old paint, industrial pollutants, leaded

gasoline gasoline

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Mercury

• Mercury bioaccumulates in the muscles of top Mercury bioaccumulates in the muscles of top

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Radioactive Substances

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Contain atoms of unstable isotopes that

spontaneously emit radiation

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Sources

• MiningMining

• Processing radioactive materialsProcessing radioactive materials • Nuclear power plantsNuclear power plants

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Thermal Pollution

o Occurs when heated Occurs when heated

water produced during water produced during

industrial processes is industrial processes is

released into released into

waterways waterways

o Organisms affectedOrganisms affected • Temperature affects Temperature affects

reproductive cycles, reproductive cycles, digestion rates, and digestion rates, and respiration rates respiration rates

• Warm water holds less Warm water holds less

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Water Quality Today

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Two Types of Water Pollution

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Point Source Pollution

• water pollution that can be traced to a specific water pollution that can be traced to a specific

origin origin

• Discharge via pipes, sewage, and ditchesDischarge via pipes, sewage, and ditches

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Non-point Source Pollution

• Pollutants that enter bodies of water over Pollutants that enter bodies of water over

large areas rather than being concentrated at large areas rather than being concentrated at

a single point of entry a single point of entry

• Diffuse, but its cumulative effect is very largeDiffuse, but its cumulative effect is very large • Ex: runoff from agricultural fields or parking Ex: runoff from agricultural fields or parking

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Water Pollution from Agriculture

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Agriculture is leading source of water

pollution in US

• Animal wastes and plants residues have high Animal wastes and plants residues have high

BOD BOD

• Chemical pesticides can leach into groundwaterChemical pesticides can leach into groundwater

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Almost all streams and rivers are polluted

with agricultural pesticides

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Municipal Water Pollution

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Industrial Wastes in Water

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Different industries generate different

pollutants

• Food processing plants- high BODFood processing plants- high BOD

• Paper mills- High BOD and toxic compoundsPaper mills- High BOD and toxic compounds

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Many industries recover toxins before

they go into the waste stream

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Case-In-Point Green Chemistry

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Groundwater Pollution

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Water Pollution in Other Countries

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Lake Maracaibo, Venezuela

• 10,000 oil wells tap lake bottom10,000 oil wells tap lake bottom

• Leak oil into lakeLeak oil into lake

• Agricultural Agricultural

wastes from wastes from

local fields local fields

• Unit recently Unit recently

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Water Pollution in Other Countries

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Po River, Italy

• Similar to Mississippi River

• Pollutants: Sewage, industrial wastes, sediment • >16 million Italians depend on the river for

drinking water

• Pollution is high

• Swimming and fishing prohibited

• Cleanup will require a national management plan

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Water Pollution in Other Countries

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Ganges River, India

• Used for bathing and Used for bathing and

washing clothing washing clothing

• Sewage and industrial Sewage and industrial

waste discharged into waste discharged into

river river

• Ganga Action Plan Ganga Action Plan

initiated by government initiated by government

• Construction of 29 sewage Construction of 29 sewage

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Improving Water

Quality-Purification of Drinking Water

Purification of Drinking Water

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In US most

municipal water

supplies are

treated

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Collected from

water or reservoir

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Treated water

distributed to

customers

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Sewer lines bring

sewage to

treatment plant

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Sewage treated at

sewage treatment

plant

Improving Water

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Purification of Drinking Water

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Chlorine Dilemma

• Chlorine kills disease causing organismsChlorine kills disease causing organisms

• Chlorine byproducts are linked to numerous Chlorine byproducts are linked to numerous

cancers, miscarriages and birth defects cancers, miscarriages and birth defects

• Peru stopped using chlorinePeru stopped using chlorine

• 1991- huge cholera epidemic that infected 300,000 1991- huge cholera epidemic that infected 300,000

people people

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Fluoridation

• Prevents tooth decayPrevents tooth decay

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Municipal Sewage Treatment

o Primary treatmentPrimary treatment

• Removing suspended and floating particles by Removing suspended and floating particles by

mechanical processes mechanical processes

o Secondary treatmentSecondary treatment

• Treating wastewater biologically to decompose Treating wastewater biologically to decompose

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Municipal Sewage Treatment

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Sewage Sludge

• Solids remaining after primary and secondary Solids remaining after primary and secondary

sewage treatment has been completed sewage treatment has been completed

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Tertiary treatment

• Advanced wastewater treatment methods that Advanced wastewater treatment methods that

are sometimes employed after primary and are sometimes employed after primary and

secondary treatments secondary treatments

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Municipal Sewage Treatment

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Individual Septic

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Individual Septic

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Laws Controlling Water Pollution

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Citizen Watchdogs to Monitor Pollution

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Safe Drinking Water Act (1974)

• Set uniform federal standards for drinking Set uniform federal standards for drinking

water water

• Maximum contaminant levelMaximum contaminant level

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Clean Water Act (1972)

• EPA sets up and monitors National Emissions EPA sets up and monitors National Emissions

Limitations Limitations

• Effectively improved water quality from point Effectively improved water quality from point