Miller Chapter 19 Water Pollution Pollution Defined Any chemical, biological, or physical change in...
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Transcript of Miller Chapter 19 Water Pollution Pollution Defined Any chemical, biological, or physical change in...
Pollution DefinedPollution Defined Any chemical , biological, or Any chemical , biological, or
physical change in water quality physical change in water quality that has a harmful effect on that has a harmful effect on living organisms or makes water living organisms or makes water unsuitable for desired uses.unsuitable for desired uses.
Types and Sources of Water Types and Sources of Water PollutionPollution
Infectious AgentsInfectious Agents Oxygen-Oxygen-
DemandingDemanding Inorganic Inorganic
ChemicalsChemicals Organic ChemicalsOrganic Chemicals Plant NutrientsPlant Nutrients SedimentSediment Radioactive Radioactive ThermalThermal
I. Methods of Determining I. Methods of Determining Water QualityWater Quality
A. Coliform BacteriaA. Coliform Bacteria 0 colonies per 100ml for drinking water0 colonies per 100ml for drinking water 200 colonies per 100ml for swimming200 colonies per 100ml for swimming
B. Biological Oxygen Demand B. Biological Oxygen Demand (BOD)(BOD)
The amount of oxygen needed by The amount of oxygen needed by decomposers to break down organic decomposers to break down organic
material over a 5-day period at 68material over a 5-day period at 680FF
Dissolved Oxygen (DO)Dissolved Oxygen (DO) Only a few species of fish can
survive when the D.O. level drops below 4 ppmWaterWater
QualityQuality
GoodGood 8-98-9
Do (ppm) at 20˚CDo (ppm) at 20˚C
SlightlySlightlypollutedpolluted
ModeratelyModeratelypollutedpollutedHeavilyHeavily
pollutedpollutedGravelyGravelypollutedpolluted
6.7-86.7-8
4.5-6.74.5-6.7
Below 4.5Below 4.5
Below 4Below 4
C. Chemical C. Chemical AnalysisAnalysis
Determine Determine the levels the levels of organic of organic and and inorganic inorganic pollutionpollution
D. Indicator SpeciesD. Indicator Species Indicator species Indicator species
can be used to can be used to monitor water monitor water qualityquality
Ex: Mussels, Ex: Mussels, Cattails, Insect Cattails, Insect larvalarva
Analyzed to Analyzed to measure the levels measure the levels of various chemicalsof various chemicals
II. Sources of PollutionII. Sources of PollutionA. Point SourcesA. Point Sources
-Discharge from a specific -Discharge from a specific location (pipe, ditch or sewer) location (pipe, ditch or sewer)
-Easier to identify and regulate-Easier to identify and regulate
Ex: Factories, Sewage Ex: Factories, Sewage Treatment Plants, Mines, Treatment Plants, Mines, Thermal Outlets and Oil Thermal Outlets and Oil Tankers.Tankers.
B. Non-Point SourcesB. Non-Point Sources
-Cannot be traced to a specific -Cannot be traced to a specific discharge discharge
-Difficult to identify and control-Difficult to identify and control
Ex: Golf Courses, Agriculture, Ex: Golf Courses, Agriculture, HomesHomes
III.Water PollutionIII.Water PollutionA. A. Rivers and StreamsRivers and Streams:: -Most pollution in the form of: chemicals from industry or
mines, malfunctioning sewage
plants, Non-point runoff Naturally, streams and
rivers can rebound: As long they are not
overloaded with pollutants & Flow is not reduced
-The breakdown of degradable -The breakdown of degradable wastes by bacteria depletes wastes by bacteria depletes dissolved oxygen dissolved oxygen
-Reduces the population of -Reduces the population of oxygen requiring organisms.oxygen requiring organisms.
-Shown as an -Shown as an OXYGEN SAG OXYGEN SAG CURVECURVE
Clean Zone DecompositionZone
Septic Zone Recovery Zone Clean Zone
(Trout, perch, bass,mayfly, stonefly)
(carp, gar,Leeches)
Fish absent, fungi,Sludge worms,
bacteria(anaerobic)
Normal clean water organisms
8 ppm
Dissolved oxygen
Biological oxygendemand
Oxygen sag
2 ppm
8 ppm
Co
nce
ntr
atio
nT
ypes
of
org
anis
ms
Time of distance downstream
Direction of flow
Point of waste orheat discharge
Trash fish
-Recovery from oxygen depletion is based on the volume of the pollutant and …
Stream Volume Flow Rate Temperature pH level
Stream and River Success Stories:Stream and River Success Stories:
-Water Pollution Control Laws of the 1970’s:
Downstream withdraw of drinking water
Reduce point-source pollution Increase # of treatment plants
-Ohio’s Cuyahoga River (caught on fire in 1959 and 1969)
Now used for boating and fishing
Stream PollutionStream Pollution: The Bad News: The Bad News Accidental release of organic and Accidental release of organic and
inorganic chemicalsinorganic chemicals Malfunctioning sewage treatment Malfunctioning sewage treatment
plantsplants Non-point run-off of pesticidesNon-point run-off of pesticidesWORLD WIDEWORLD WIDE:: 2/3 of streams monitored in 2/3 of streams monitored in ChinaChina
and and IndiaIndia are severely polluted are severely polluted
B. B. LakesLakes-More vulnerable than streams
due to… Stratified layers, Little flow, Low water volumes. Vulnerable to Biological Biological
MagnificationMagnification & & Cultural EutrificationCultural Eutrification:: Human activities that increase
the level of plant nutrients in lakes
Rainbow smelt1.04 ppm
Zooplankton0.123 ppm
Phytoplankton0.0025 ppm
Water0.000002 ppm
Herring gull124 ppm
Lake trout4.83 ppm
Herring gull eggs124 ppm
Cultural EutrophicationCultural EutrophicationDischarge of untreated
municipal sewage(nitrates and phosphates)
Nitrogen compoundsproduced by cars
and factories
Discharge of treatedmunicipal sewage
(primary and secondarytreatment:
nitrates and phosphates)
Discharge of detergents
( phosphates)
Natural runoff(nitrates andphosphates
Manure runoffFrom feedlots(nitrates andPhosphates,
ammonia)
Dissolving of nitrogen oxides
(from internal combustionengines and furnaces)
Runoff and erosion(from from cultivation,mining, construction,
and poor land use)
Runoff from streets,lawns, and construction
lots (nitrates andphosphates)
Lake ecosystemnutrient overload
and breakdown of chemical cycling
C. C. GroundwaterGroundwater
- Easily contaminated by - Easily contaminated by everyday activitieseveryday activities
- Flows slowly so it cannot - Flows slowly so it cannot dilute/disperse dilute/disperse contaminantscontaminants
- Small population of - Small population of decomposersdecomposers
- Cold temps. Slow Rx that - Cold temps. Slow Rx that remove wastesremove wastes
Extent of Contamination:Extent of Contamination:
- Up to 25% of usable, U.S. - Up to 25% of usable, U.S. groundwatergroundwater
- 60% of liquid waste injected - 60% of liquid waste injected into deep underground wellsinto deep underground wells
- Pumping of water at - Pumping of water at coastlines causes coastlines causes contamination of drinking contamination of drinking water by saltwater intrusion.water by saltwater intrusion.
Waste lagoon,pond, or basin
Miningsite
Pumpingwell
Waterpumping
well
Sewer
Cesspool,septictank
Hazardous wasteinjectionwell
Buried gasolineand solvent
tanksLandfill
Roadsalt
Unconfined freshwater aquifer
Confined freshwater aquifer
Confined aquifer Discharge
Leakagefrom faultycasingGroundwater
Groundwater flow
IV. Preventing/Reducing IV. Preventing/Reducing Water PollutionWater Pollution
1.1. PreventionPrevention::
-Wiser use of fertilizer and pesticides
-Plant buffer zones to control runoff
-Banning Deep Injection Wells
-Monitoring of waterways and aquifers
-Clean Water Act (1977)
-Water Quality Act (1987)
Householdwastewater
Perforatedpipe
Distributionbox
(optional)
Septic tank
Manhole (forcleanout)
Drainfield
Vent pipe
Nonperforatedpipe
Gravel orcrushedstone
2. Reduction:2. Reduction:- Septic Systems- Septic Systems
--Sewage TreatmentSewage Treatment
3 Levels of Purification
A. Primary –
mechanical treatment
B. Secondary –
biological treatment
C. Advanced –
Specialized chemical and physical processes to remove specific contaminants
Raw sewagefrom sewers
Bar screenGritchamber Settling tank Aeration tankSettling tank
Chlorinedisinfection tank
Sludge
Sludge digester
Activated sludge
Air pump
(kills bacteria)
To river, lake,or ocean
Sludge drying bed
Disposed of in landfill orocean or applied to cropland,pasture, or rangeland
Primary Secondary
Fig. 19.15, p. 494
Effluent fromSecondarytreatment
Alumflocculation
plus sedimentsActivated
carbon
Desalination(electrodialysis
or reverse osmosis)Nitrate
removal
Specializedcompound
removal(DDT, etc.)
98% ofsuspended solids
90% ofphosphates
98% ofdissolvedorganics
Most ofdissolved salts
Recycled to landfor irrigation
and fertilization
To rivers, lakes,streams, oceans,
reservoirs, or industries
What about the Sludge?What about the Sludge? Sewage sludge is a highly toxic Sewage sludge is a highly toxic
mix of chemicals, infectious mix of chemicals, infectious agents, and settle solids.agents, and settle solids.
-9% converted to compost-9% converted to compost -36% applied as fertilizer-36% applied as fertilizer -55% dumped in landfills or -55% dumped in landfills or burnedburned
(1) Raw sewage drains by gravity into the first pool and flows through a long perforated PVC pipe into a bed of limestone gravel.
(3) Wastewater flows through another perforated pipe into a second pool, where the same process is repeated.
(2) Microbes in the limestone gravel break down the sewage into chemicals, that can be absorbed by the plant roots, and the gravel absorbs phosphorus.
(4) Treated water flowing from the second pool is nearly free of bacteria and plant nutrients. Treated water can be recycled for irrigation and flushing toilets.
45 centimeterlayer of limestonegravel coated with
decomposing bacteriaFirst concrete pool Second concrete pool
Sewage
Wetland typeplants
Wetland typeplants
Treatedwater
-Wastewater Gardens-Wastewater Gardens
V. Drinking Water QualityV. Drinking Water QualityV. Drinking Water QualityV. Drinking Water Quality-In U.S. we have safe drinking water standards set by the Safe Drinking Water Act of 1974
-Establishes Maximum Maximum Contamination LevelsContamination Levels for any pollutants.
-Effects “city” water only, not wells.
-Purification of water done in various ways