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Transcript of Pollution
Air Pollution - primary & secondary sources, major air pollutants, measurement units, smog, acid deposition - causes & effects, heat islands, and temperature inversions, indoor air pollution, remediation & reduction strategies, Clean Air Act, and other relevant laws.
Noise Pollution - sources, effects, and control measures
Water Pollution - types, sources, causes and effects, cultural eutrophication, groundwater pollution, maintaining water quality, water purification, sewage treatment / septic systems, Clean Water Act, and other relevant laws
Solid Waste - types, disposal, and reduction.
Impacts on the Environment and Human Health:
Hazards to human health - environmental risk analysis, acute and chronic effects, does-response relationships, air pollutants, smoking, etc.
Hazardous chemicals in the environment - types of hazardous waste, treatment / disposal of waste, cleanup of contaminated sites, biomagnificaiton, and relevant laws.
- cost-benefit analysis, externalities, marginal costs, and sustainability
Types of Pollution
Adapted from Barron's AP Environmental Science
March 17, 2014
: pollutants emitted directly into air from natural sources (volcanoes, cars, industrial smokestacks)
examples: particulates or "soot" (PM10), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon dioxide (CO2), and carbon monoxide (CO).
result from reaction of primary pollutants in atmosphere to form new pollutants (sulfur trioxide (SO3), sulfuric acid (H2SO4), ozone (O3), photochemical smog (PANS and peroxyacyl nitrates.
Major Air Pollutants
Nitrogen Dioxide (NO2)
: forms when fuels burned at high temperatures. Also results from forest fires, volcanoes, lightning, & bacterial action in soil. Forms nitric acid (HNO3) in air and contributes to acid deposition & cultural eutrophication. Results in lung damage, suppresses plant growth & may be carcinogenic.
Criteria Air Pollutants:
air pollutants that cause smog, acid rain, and other health hazards; typically emitted from industrial, mining, transportation, power generation, and agricultural sources. First set of pollutant recognized by EPA as needing regulation. Most cases, they're products of combustion of fossil fuels. Examples (ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen oxides and lead.
: major component of photochemical smog; formed by sunlight reacting with NOx and VOCs in air; causes lung irritation, bronchial constriction, coughing, wheezing, and eye irritation; defoliates plants and damages rubber and plastics.
Peroxyacyl Nitrates (PANs)
: secondary air pollutants formed from reaction of hydrocarbons with oxygen and nitrogen dioxide and catalysis by UV radiation: hydrocarbons + O2 + NO2 + light = CH3COOONO2 (PAN). They dissociate slowly (persistent) in atmosphere and may be transported far from source; transport NOx to regions where it can produce ozone. Can cause eye irritation and damage vegetation.
Sulfur Dioxide (SO2):
produced by combustion of high-sulfur oil or coal, smelting of metals, and paper manufacturing. Combines with water vapor to produce acid rain, causes breathing issues; reduction of SO2 emissions in US reflects success of Acid Rain Program and Clean Air Act.
Suspended Particulate Matter (PM10)
: particulates with diameter of 1/7 the width of a human hair or less and include smoke, dust, diesel soot, lead, & asbestos. PM10 cause lung irritation and damage. Many are mutagens, teratogens, & carcinogens. Reduction of PM10 would produce health benefits 10 x greater than similar reductions in all other air pollutants combined.
Volatile Organic Compounds (VOCs)
: organic compounds with high vapor pressure; over 600 compounds identified; examples) toluene, xylene, formaldehyde, benzene, acetone; found in paints, aerosols, sprays, dry-cleaning fluids, & industrial solvents; causes kidney & central nervous system damage; concentration of VOCs may be 1000 times higher indoors than outdoors.
Air pollutants are most often expressed in
parts per million (ppm)
; 1 ppm represents on particle of a pollutant for every 999,999 particles of air. The symbol u is often used to represent a millionth; concentration is equivalent to one drop of ink in 40 gallons (150 L) of water or one second in 280 hours. To change ppm to percentage, move decimal place four places to left and add a % sign. Ex) a concentration of 400 ppm (0.04%) or carbon monoxide may be fatal.
Two other common measurements are
parts per billion (ppb or nano)
parts per trillion (ppt or pico)
Smog: two forms of smog (industrial & photochemical)
Industrial: usually sulfur-based (aka grey-air smog)
Photochemical: catalyzed by UV radiation & tends to be nitrogen based (aka brown air smog)
Formation of Industrial Smog
1. Carbon in coal or oil is burned in oxygen gas to produce carbon dioxide and carbon monoxide gas C + O2 = CO2 & C + O2 = CO (incomplete combustion)
2. Unburned carbon ends up as soot or particulate matter (PM) = (C)
3. Sulfur in oil and coal reacts with oxygen gas to produce sulfur dioxide S + O2 = SO2
4. Sulfur dioxide reacts with oxygen gas to produce sulfur trioxide SO2 + O2 = SO3
5. Sulfur trioxide reacts with water vapor in the air to form sulfuric acid SO3 + H2O = H2SO4
6. Sulfuric acid reacts with atmospheric ammonia to form brown, solid ammonium sulfate
H2SO4 + NH3 = (NH4)2SO4
Formation of Photochemical Smog
Net result: NO + VOCs + O2 + UV light = O3 + PANs
6 A.M. - 9 A.M
As people drive to work, concentrations of nitrogen oxides and VOCs increase: N2 + O2 = 2NO; NO + VOCs = NO2; NO2 (UV radiation) = NO + O
9 A.M - 11 A.M
As traffic decreases, nitrogen oxides and VOCs begin to react, forming nitrogen dioxide: 2NO + O2 = 2NO2
11 A.M - 4 P.M
As sunlight intensifies, nitrogen dioxide is broken down and concentration of ozone increases: NO2 (UV) = NO + O; O2 + O = O3
Nitrogen dioxide also reacts with water vapor producing nitric acid and nitric oxide: 3NO2 + H2O = 2HNO3 + NO
Nitrogen dioxide can also react with VOCs released by vehicles, refineries, gas stations, etc., to produce PANs (peroxacyl nitrates): NO2 + VOCs = PANs
4 P.M. - Sunset
As sun goes down, the production of ozone is halted
Great Smog of '52
: a period of cold weather, combined with windless conditions, collected airborne pollutants mostly from the use of coal to form a thick layer of (gray) smog over London in 1952. It lasted from December 5-9, 1952, and then dispersed quickly after a change of weather. Estimates run as high as 100,000 people becoming ill and over 12,000 deaths
London Smog '52
an exhaust emission control device that converts toxic chemicals in exhaust from internal combustion engine into less noxious substances.
Present day vehicles are fitted with "three-way" converter since it covers the three main pollutants:
a) reduction of nitrogen oxides to nitrogen & oxygen
b) oxidation of carbon monoxide to carbon dioxide
c) oxidation of unburned hydrocarbons to carbon dioxide and water
catalytic converters do NOT reduce carbon dioxide (GHG) and they release nitrous oxides (N2O), another GHG that's over 300 times more potent than CO2.
Acid Deposition - Causes & Effects
two parts (wet & dry);
: refers to acid rain, fog, and snow
impact on environment depends upon pH, buffering capacity of soil or water, type of organism impacted
refers to acid gases and particles; 1/2 of acidity in atmosphere returns to Earth as dry deposition; wind blows these particles onto buildings, cars, homes, & trees; rainwater leaches this dry deposition into waterways, combining them with wet deposition (worsening acid deposition)
Sulfur Dioxide (SO2)
: formed from burning of coal, oil, smelting metals, organic decay, & ocean spray; (SO2 + H2O = H2SO4)
Nitrogen Oxides (NOx)
: produced from coal, oil, natural gas; found in volcanoes, formed by forest fires, bacterial action in soil, and lightning reactions in atmosphere; Nitrogen Monoxide (NO reactsi with O2 to produce NO2, which then reacts with water vapor (H2O) to create HNO3. (2NO2 + H2O = HNO2 + HNO3)
: acidifies lakes and steams, damages trees, acidifies soil impacting decomposers, causes "acid shock" (sudden acid snow melts shocks aquatic life by lowering pH), leaches plant nutrients from soil, causes eutrophication, destroys limestone and marble structures, etc.
Heat Islands & Temperature Inversions
occur in urban areas significantly warmer than surroundings (can be 10F warmer than surrounding areas)
warmer air retains more moisture so rainfall can be 30% greater downwind of cities than upwind.
higher nighttime temps in urban areas due to retention of heat by buildings (brick, concrete, asphalt have higher heat capacity)
lack of shade (trees) also allows for greater heat absorption.
human activities (cars, air conditioning, industry) increases heat
higher levels of pollutants create localized greenhouse effect
heat islands can alter local wind patterns, precipitation, etc.
: occurs when air temps increase with height above the ground, as opposed to normal decrease in temperature with height.Typically occurs at night when cooler air directly above land gets trapped by the warm air above it, trapping pollutants.
leads to pollution such as smog being trapped close to ground
can cause asthma, emphysema, increase in lung cancer
In 1948, 20 people were asphyxiated and over 7,000 were hospitalized or became ill as the result of severe air pollution over Donora, PA, a town of 14,000. Smog from the local zinc and steel smelting plants settled in the valley where the town was located. Four days later, winds finally cleared the toxins from the town. The investigation of this incident by state and federal health officials resulted in the first meaningful federal and state laws to control air pollution and marked the beginning of modern efforts to assess and deal with the health threats from air pollution.
Indoor Air Pollution (Sick Building Syndrome)
Sick Building Syndrome (SBS)
: a term used to describe a combination of ailments (a syndrome) associated with an individual's place or work or residence.
indoor air pollution may be 25 - 60% greater than outdoor levels
up to 1/3 of new and remodeled buildings may be linked to SBS
most common indoor pollutants (molds, bacteria, CO, radon, allergens, asbestos, tobacco smoke, formaldehyde, and VOCs released from carpeting, adhesives, and particleboard.
SBS frequently pinned down to flaws in heating, ventilation, and air conditioning (HVAC)
symptoms include headaches, breathing difficulties, allergies, asthma, cancer, emphysema, and various nerve disorders
Remediation & Reduction Strategies
1. tax incentives for pollution control rather than fines and penalties
2. setting legislative standards for energy efficiency
3. increase funding for research into renewable energy
4. incorporating incentives for reducing air pollution into trade policies
5. distributing solar cookstoves to developoing countries to replace coal and firewood
6. phasing out two-cycle gasoline engines
7. for issues involving SBS: modify building codes, replace / repair water damage (control mold), uses paints & adhesives, etc. during periods of non-occupancy, maintain HVAC systems
8. provide incentives to use mass transit
Remediation & Reduction Strategies
Designing more efficient engines to reduce NOx emissions
Increase efficiency of coal-burning plants to reduce SO2, NOx, and particulate emissions
Wash coal and incorporate scrubbers, advanced filtration smokestacks, electrostatic precipitators, and staged catalytic burners with afterburners
Increase penalties on stationary sources that don't reduce emissions
Provide tax incentives to companies that reduce pollutants,
Continue Energy Star appliance production and CAFE standards
EPA's Acid Rain Program:
designed to reduce SO2 and NOx emissions
employs both traditional and innovative market-based approaches for controlling air pollution
continuous emissions monitoring (CEM) requirements
Clean Air Act (signed into law 1963; goal was to protect public health from air pollution; reenacted in 1990 to address acid rain, urban smog, air pollutants, ozone, VOCs; estimated that Clean Air Act saves 15,000 lives annually
Clean Air Act Record (showing reductions and additions)
Pb - 98%; VOC -42%; SO2 -37%; CO -31%; NOx +17%; PM10 +266%
1977 Kyoto Protocol
1997 Kyoto Protocol would have required US to reduce greenhouse emissions by 7%
Under this agreement, US would have faced penalties if it did not meet these cuts.
US saw this as unattainable since CO2 and GHG continue to increase and are projected to increase for the next 20 years.
US felt developed nations had to shoulder more responsibility than developing nations
US claimed 1) cost of meeting requirements was too high, 2) the time frame was too short for implementation, and 3) there was no evidence correlating GHG to global warming
In 2012, the year the 1997 Kyoto Protocol expired, Canada, Japan, & Russia joined the US stating that they will not agree to an extension of the Kyoto Protocol unless the unbalanced requirements of developing countries are changed.
Relevant Laws & Protocols
Air Pollution Control Act
(1955): the nation's first piece of federal legislation regarding air pollution; identified air pollution as a national problem and announced that research and additional steps to improve the situation needed to be taken. It was an act to make the nation more aware of this environmental hazard.
Clean Air Act
(1963): designed to control air pollution on a national level. It requires the EPA to develop and enforce regulations to protect the general public from exposure to airborne contaminants that are known to be hazardous to human health. The act (amended in 1967, 1977, & 1990):
required comprehensive federal and state regulations for both stationary (industrial) and mobile sources of air pollution.
expanded federal enforcement authority
addressed acid rain, ozone depletion, and toxic air pollution
established new auto gasoline reformulation requirements
was 1st major law in US to include provisions for citizen suits
National Environmental Policy Act
(1970): created the EPA. Also mandated creation of Environmental Impact Statements.
(1989): an agreement among nations requiring the phaseout of ozone layer damaging chemicals (CFCs)
Pollution Prevention Act
(1990): requires industries to reduce pollution at its source. Reduction can be in terms of volume and/or toxicity
(1997 and 2001): agreement among 150 nations requiring GHG reductions.
: unwanted human-created sound that disrupts the environment.
most common form results from transportation (motor vehicles, aircraft noise, rail transport noise)
other sources include office equipment, factory machinery, appliances, power tools, & audio systems
Federal Noise Control Act
(1972): regulates noise pollution
3 types of hearing loss: conductive, sensory, & neural (sensory is most commonly associated with noise pollution)
cardiovascular problems, gastric-intestinal problems, decrease in alertness & ability to memorize, nervousness, pupil dilation, insomnia, nervousness, bulimia, high blood pressure, anxiety, depression, & sexual dysfunction
Roadway noise can be reduced through use of:
limitations on vehicle speed
newer roadway surface technologies
limiting times for heavy-duty vehicles
computer-controlled traffic flow devices (reduce braking and acceleration)
changes in tire tread design
Aircraft noise can be reduced through:
developing quieter jet engines
rescheduling takeoff and landing times
Industrial noise can be reduced through:
new technologies in equipment
installation of noise barriers
Residential noise (power tools, garden equipment, loud radios, etc. can be controlled through laws.
Noise Control Act
(1972): establishes national policy to promote an environment for all Americans free from noise that jeopardizes their health and welfare. To accomplish this, the act establishes a means for coordination of federal research and activities in noise control, authorizes the establishment of federal noise emissions standards for products distributed in commerce, and provides information to the public respecting the noise emission and noise reduction characteristics of such products.
: can originate from either point or nonpoint source.
: occurs when harmful substances are emitted DIRECTLY into a body of water. examples: pollution from a pipe from an industrial facility discharging effluent directly into a river. Point source pollution can be easily monitored.
: delivers pollutants INDIRECTLY through transport or environmental change. example: when fertilizer from a farm field is carried into a stream by rain (run off). Nonpoint sources are much more difficult to monitor and control, and account for majority of contaminants in streams and lakes.
Sources of Water Pollution
Pollutants like mercury, sulfur dioxide, nitric oxides, & ammonia fall out of air and into water. Can cause mercury contamination in fish and acidification and eutrophication of lakes.
Oceans have absorbed enough CO2 to have already caused slight increase in ocean acidification and may be causing carbonate structures like corals, algae, and marine plankton to dissolve. These organisms create base of food pyramid in ocean.
Mercury pollution is both natural and anthropogenic
Natural sources include:
natural mercury deposits
volatilization from ocean
Humans have doubled or tripled atmospheric mercury
Mercury undergoes bioaccumulation (compounded longer the organism lives)
Humans uptake mercury one of two ways: as methylmercury (CH2Hg) from fish consumption, or breathing vaporous mercury in ambient air.
Most mercury to aquatic ecosystem comes from atmospheric deposition
Studies show that bacteria that process sulfate (SO4) take up mercury in its inorganic form and convert it to methylmercury - important for TWO reasons: 1) methylmercury is more toxic than inorganic mercury and 2) organisms require longer to eliminate methylmercury than elemental mercury; methylmercury-containing bacteria may be consumed by higher trophic level in food chain or bacteria may release methylmercury to water where it's absorbed by plankton.
Other examples of chemicals that cause water pollution:
accumulate in shellfish
poison organisms (people, birds, animals)
Per square foot basis, homeowners apply more chemicals to lawns than farmers do their fields.
Discharge of oily wastes and oil-containing ballast water and wash also significant sources of marine pollution.
Drilling and extraction operations for oil and gas also contaminate coastal waters and groundwater (in Santa Monica, CA, wells supplying half the city's water have been closed due to dangerous levels of the gasoline additive MTBE.
Chronic exposure to PAHs can affect the development of marine organisms, increase susceptibility to disease, and jeopardize normal reproductive cycles in many marine species
Studies show that up to 90% of drug prescriptions pass through body unaltered; growth hormones & antibiotics via animal farms also find their way into water bodies.
Hormone-mimicking chemicals have also impacted organisms
Disease-causing (pathogenic) microorganisms such as bacteria, viruses, and protozoa can sicken swimmers, fish, and shellfish. Examples include: cholera, typhoid, shigella, polio, meningitis, ciguaterra, & hepatitis.
90% of untreated waste-water is discharged directly into rivers and streams in developing nations.
In US, 850 billion gallons of raw sewage is dumped into rivers, lakes, and bays each year via leaking sewer systems and inadequate sewer / storm systems that overflow during flooding.
Leaking septic tanks and other sources of sewage can also cause groundwater and steam contamination.
Beaches suffer the effets of water pollution from sewage. (25% of all US beaches have pollution advisories or are closed each year due to bacteria build-up caused by sewage.
mining causes water pollution in following ways:
exposes heavy metals and sulfur compounds previously locked within Earth
rainfall leaches compounds, resulting in acid mine drainage & heavy-metal pollution
rainwater leaches pollution from mining waste (tailings) into freshwater
cyanide poured onto piles of rock (leach heap mining used in gold extraction) can find its way into water supplies
mining slurry waste leaks or infiltrates groundwater supplies
mining waste in developing countries often dumped directly into rivers and other bodies water
in 2003, US reclassified mining waste from mountaintop removal so it could be dumped directly into valleys and streams
Many organisms rely on sound to communicate / navigate. ex) marine mammals, sea turtles, fish, seabirds, etc.
Oceanic water noise pollution caused by commercial shipping, military sonar, & recreational boating may impede life activities (hunting, avoiding predators, navigating, mating, etc.)
Phosphorus and Nitrogen necessary for plant growth and are abundant in untreated waste-water.
When added to water bodies, they can cause eutrophication.
If the source if from humans, we refer to this as cultural eutrophication
Deposition of nutrients (SO2, NOx, etc.) in atmosphere also contribute to eutrophication
Oil is main global energy source
Because unevenly distributed, must be transported by ship or pipeline, resulting in accidental spills, etc.
Oil may penetrate feathers of seabirds, reducing their insulating ability and buoyancy, disallowing them to hunt (starvation).
Attempts to preen, result in ingestion of oil, damaging their kidneys and liver (dehydration).
Because oil floats atop water, sunlight penetration is reduced, limiting photosynthesis of marine plants and phytoplankton (basis for food chain).
Oil spill recovery is difficult and dependent upon:
type of oil spilled, temperature of water, types of shoreline and beaches.
Methods of remediation:
use microorganisms to break down oil, absorb it, force it to clump using gel-like agglomerations that sink, controlled burning, booming & skimming, use of dispersants, or vacuuming it from shoreline.
Biodegradable wastes used as nutrient by bacteria.
Excessive biodegradable wastes can deplete O2 in receiving waters, increasing anaerobic bacteria that produce ammonia, amines, sulfides, & methane (swamp gas), contributing to "Dead Zones"
Pacific Trash Vortex
("Great Pacific Garbage Patch"): a large system of rotating ocean currents (gyre) of marine litter in the central North Pacific Ocean characterized by:
large concentration of floating plastics
Gyre's rotational pattern collects waste material from across North Pacific Ocean, including coastal waters off North America and Japan.
Estimates of its size range from 0.5% to 8.1% of the size of the entire Pacific Ocean.
As plastics photodegrade into smaller fragments, leaching of toxins occur (bisphenol A and PCBs).
These enter the marine food chain, ending up in the stomachs of marine birds, cetaceans (dolphins and whales), pinepeds (seals & sea lions),
Fragments also perpetuate spread of invasive species that attach to floating debris and travel long distances.
On macroscopic level, the physical size of the plastics kills organisms because the plastics cannot be digested inside the organism's stomach
Plastics estimated to impact over 250 species worldwide
Suspended wastes eventually settle out of water and form silt or mud along benthos.
Toxic materials can accumulate in sediment and affect organisms throughout food-web.
When forests are clear-cut, root systems that held soil die and sedimentation increases, entering streams, rivers, lakes, etc.
Plastics and other plastic-like substances (nylon, fishing lines, etc.) can entangle fish, sea turtles, and marine mammals
Certain plastics degrade into microparticles and become ingested by zooplankton, bioaccumulating through the food chain.
: produced by industry and power plants.
Heat reduces ability of water to retain oxygen, causing death to organisms that cannot tolerate heat and / or low oxygen levels.
Global warming is also impairing additional heat to oceans, rivers, and streams with unknown consequences
: 27 tons of mercury-containing compouds from industrial processes were dumped into Minamata Bay in Japan between 1932 - 1968. The mercury bio-concentrated in fish and shellfish caught in the bay. Symptoms included blurred vision, hearing loss, loss of muscular coordination, and reproductive disorders.
(1989): In 1989, oil tanker Exxon Valdez spilled 11 to 30 million gallons of crude oil in Prince Williams Sound, AK. As result, 250,000 sea birds, 3,000 otters, 300 seals, 300 bald eagles, and 22 whales died along with billions of salmon and herring eggs. The oil also destroyed the majority of the plankton in the sound.
Gulf of Mexico Oil Spill
(2010): In April 2010, a massive oil spill followed an explosion on the Deepwater Horizon offshore drilling rig operated by British Petroleum, becoming the most significant envrionmental disaster to occur in the US. When oil from well site reached the Gulf coast, billions of dollars in damage was done to the Gulf of Mexico fishing industry, the tourism industry, and the habitat of hundreds of birds, fish, and other wildlife species.
: defined as the process whereby human activity increases the amount of nutrients entering surface waters.
Two most important nutrients associated with eutrophication (nitrates (NO3) and phosphates (PO4) derived from fertilizer, sewage discharge, and animal waste.
Nitrates are water-soluble; can remain on fields and accumulate, leach into groundwater, and end up in surface runoff, and /or volatize and enter atmosphere where they contribute to acid precipitation.
Nitrates can cause nitrate poisoning in water supplies, reduce effectiveness of hemoglobin, and may be responsible for worldwide declines in amphibians.
Phosphates also component of inorganic fertilizers; they are NOT water soluble and adhere to soil particles.
Soil erosion contributes to build-up of phosphates in water supplies.
Phosphate buildup in more damaging in freshwater systems; in contrast, nitrate pollution is more damaging in wetlands where nitrogen is a limiting factor
Nitrates and phosphates are algal nutrients - can cause eutrophication
plant vegetation buffers zones along streambeds to slow erosion & absorb nutrients
control application of fertilizer
control runoff from feedlots
using biological controls such as denitrifying bacteria that convert nitrates into atmospheric nitrogen
50% of people in US depend on groundwater for water supplies
Some countries, may be as high as 95%
50% of water used for agriculture comes from groundwater
EPA estimates each day, 4.5 trillion liters of contaminated water seep into groundwater supplies in US
60% of most hazardous liquid waste solvents, heavy metals, and radioactive materials injected directly into groundwater via thousands of injection wells
Although EPA requires these contaminants to be injected below deepest source of drinking water, some pollutants already entered water supplies in FL, TX, OH, and OK.
Water in aquifer may remain there for 1,400 years
Once aquifer contaminated, it's practically impossible to remove pollutants.
Maintaining Water Quality Water Purification
Drinking Water Treatment Methods
: contaminants stick to the surface of granular or powdered activated charcoal
: chlorine, chloramines, chlorine dioxide, ozone, and UV radiation
: removes clay, silts, natural organic matter, and precipitants from the treatment process. Filtration clarifies water and enhances the effectiveness of disinfection
: process that combines small particles into larger particles that then settle out of the water as sediment. Alum, iron salts, or synthetic organic polymers are generally used to promote coagulation.
: removes inorganic constituents. It can be used to remove arsenic, chromium, excess fluoride, nitrates, radium, and uranium.
Water Treatment Remediation Technologies
Adsorption / Absorptio
n: solutes concentrate at the surface of a sorbent (an absorbing surface), thereby reducing their concentration.
: bubbling air through water increases rates of oxidation.
: VOCs are separated from groundwater by exposing water to air (the VOCs evaporate due to their high vapor pressure).
: groundwater is acted upon by microorganisms
: uses natural geochemical and biological processes that parallel natural wetlands. Also known as "living machines"
: uses injection wells to place treated or untreated liquid waste into geological formations that do not pose a potential risk to groundwater.
: the natural rate of bioremediation is enhanced by adding oxygen and nutrients into groundwater.
a vacuum system is applied to low permeable soil to remove liquids and gases.
Granulated activated carbon (GAC)
: groundwater is pumped through a series of columns containing activated carbon.
Hot water or steam flushing:
steam or hot water is forced into an aquifer to vaporize volatile contaminants and is then treated through fluid-vapor extraction.
In-well air stripping:
air is injected into wells - the air picks up various contaminants, particularly VOCs. Vapors are drawn off by vapor extraction.
involves exchange or one ion for another.
uses plants to remove contamination.
uses UV light, ozone, or hydrogen peroxide to destroy microbiological contaminants.
Sewage Treatment / Septic Systems
Sewage Treatment: incorporates physical, chemical, and biological processes to remove contaminants from waste-water.
Septic treatment: incorporates a tank and drain field; waste-water enters tank where solids settle. Anaerobic digestion using bacteria treats the settled solids and reduces their volume. Excess liquid exits tank and moves through a perforated pipe where it drains into a leach field where water percolates into the soil.
Some pollutants (especially nitrogen) do not decompose in a septic system and may contaminate groundwater. (25% of Americans rely on septic)
(SEPARATION OF SOLIDS):
reduces oils, greases, fats, sand, grit, and course solids. Steps include sand catchers, screens, sedimentation. This is a
method of cleaning.
(BREAKDOWN BY BACTERIA):
designed to degrade the biological content of sewage from human waste, food waste, soaps, and detergent. Steps include filters, activated sludge, filter (oxidation) beds, trickling filter beds using plastic media, and secondary sedimentation. This is a
L method of cleaning.
Final stage of treatment that raises the effluent quality prior to release / discharge into a receiving water body (sea, river, lake, or ground). May include sand filtration, lagooning, constructed wetlands, nutrient removal through biological or chemical precipitation, denitrification using bacteria, phosphorus removal using bacteria, microfiltration, and disinfection using UV light, chlorine, or ozone. This is a
method of cleaning
Sewage Treatment Plant
Clean Water Act (1972): established the basic structure for regulating discharges of pollutants into the waters of the US. Gave EPA authority to implement pollution control programs such as setting wastewater standards for industry. Also set regulations for all surface waters and made it unlawful for people to discharge any pollutant from a point source into navigable waters unless permit obtained. Funded sewage treatment plant construction grants program.
Safe Drinking Water Act (1974): established standards for drinking water in US
Ocean Dumping Ban Act (1988): made it unlawful for people to dump or transport sewage, sludge, or industrial waste in ocean.
Oil Spill Prevention & Liability Act (1990): strenthened EPAs ability to prevent and respond to catastrophic oil spills.
Types of Solid Waste:
Organic: kitchen waste, vegetables, flowers, leaves, fruits. Usually breaks down within 2 weeks. Wood can take 10 - 15 years.
Radioactive: spent fuel rods & smoke detectors. Can take thousands of years to decompose.
Recyclable: paper, glass, metals, some plastics; paper decomposes in 10 to 30 days; glass does not decompose; metals decompose in 100 - 500 years; some plastics can take up to 1 million years to decompose.
Soiled: hospital waste; cotton and cloth can take 2- 5 months to decompose.
Toxic: paints, chemicals, pesticides, etc. Toxic wastes can take hundreds of years to decompose.
Amounts and Types of Municipal Solid Waste (SSW) in the US
Disposal & Reduction
Pacific Trash Vortex
Gulf of Mexico Spill
Waste Water Treatment Plant
Burning, Incineration, or Energy Recovery
heat can be recycled to supplement energy requirements
reduces impact on landfill
mass burning is inexpensive
what remains is 10% - 20% of original volume
US incinerates 15% of its wastes
France, Japan, Sweden & Switzerland incernerate more than 40% of their wastes and use the heat to generate electricity
air pollution (lead, mercury, NOx, cadmium, SO2, HCL, & dioxins
sorting out batteries, plastics, etc. is expensive
no way of knowing toxic substances
initial incineration costs are high
adds to acid precipitation and global warming
Disposal & Reduction
creates nutrient rich soil additive
aids in water retention
slows down soil erosion
no major toxic issues
public reaction to odor, vermin, etc.
no in my bachyard (NIMBY)
Disposal & Reduction
recovers materials that would have been discarded
benefits inner cities & industry because material is available and jobs are needed
toxic materials may be present (CFCs, heavy metals, toxic chemicals, etc.)
Disposal & Reduction
reduces impact on the environment
Disposal & Reduction
gets rid of problem immediately
sources of income for poor countries
garbage imperialism or evironmental racism
long-term effect unknown
expensive to transport
Disposal & Reduction
Land Disposal - Sanitary Landfills:
waste is covered daily to deter insects and rodents
plastic liners, drainage systems, etc. help control leaching material into groundwater
geological studies and env. impact studies are performed prior to construction
collection of methane & use of fuel cells to supplement energy demand
use of anaerobic methane generators reduces dependence on other fuel sources
rising land prices (current costs re $1 million per hectare)
transportation costs to the landfill
high cost of running and monitoring landfill
limited suitable areas
degradable plastics do not decompose completely
Disposal & Reduction
Land Disposal - Open Dumping
provides a source of income to the poor by providing recyclable products to sell
trash blows away with wind
vermin and associated diseases
leaching of toxic material into soil
Disposal & Reduction
debris floating to unintended areas
marine organisms & food webs are impacted
illegal in the US
Disposal & Reduction
converts waste to inexpensive resource
reduces impact on landfills
reduces need for raw material
reduces energy requirements to produce product
reduces dependence on foreign oil
reduces air and water pollution
bottle bills provides economic incentive to recycle
throw-away packaging more popular
current policies favor extraction of raw material
Disposal & Reduction
most efficient method of reclaiming material
industry models already in place - auto salvage yards, building materials, etc.
refillable glass bottles can be reused approximately 15 times
cloth diapers do not impact landfills
cost of collecting material on large scale is expensive
cost of washing contaminaed containers, etc.
only when items are expensive and labor is cheap is reuse economical
Resource Conservation & Recovery Act (RCRA)
(1976): encouraged states to develop comprehensive plans to manage nonhazardous industrial solid and municipal wastes. Set criteria to municipal landfills and disposal facilities, and prohibited open dumping of solid waste.
Toxic Substances Control Act (TOSCA)
(1976): gave EPA authority to track industrial chemicals produced wtin or imported into US. Allows EPA to ban manufacturing or importation of chemicals that pose risks.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA - Superfund)
(1980): provided authority for federal government to respond to releases or possible releases of hazardous substances that could threaten public health and / or environment. Established rules for closed and abandoned hazardous waste sites; established liability for corporations responsible for hazardous waste sites; created trust fund for cleanup if responsible parties for contaminated sites could not be located
Nuclear Waste Policy Act
(1982): established federal authority to provide locations for permanent disposal of high-level radioactive wastes and required operators of nuclear power plants to pay costs of permanent disposal
Quick Review Checklist
major air pollutants
suspended particulate matter (PM)
volatile organic compounds (VOCs)
formation of industrial smog
formation of photochemical smog
causes and effects
indoor air pollution
remediation and reduction strategies
relevant laws and protocols
Air Pollution Control Act (1955)
Clean Air Act (1963)
National Environmental Policy Act (1969)
Montreal Protocol (1989)
Pollution Prevention Act (1990)
Kyoto Protocol (1997)
Noise Pollution (causes, effects, control)
Noise Control Act (1972)
oxygen depleting substances
Exxon Valdez (1989)
Maintaining Water Quality & Water Purification
Sewage Treatment / Septic Systems
primary, secondary, tertiary
Clean Water Act (1972)
Safe Drinking Water Act (1974)
Ocean Dumping Act (1988)
Oil Spill Prevention and Liability Act (1990)
disposal and reduction methods
Resource Conservation & Recovery Act (1976)
Toxi Substance Control Act (TOSCA) (1976)
Nuclear Waste Policy Act (1982)
Types of Smog
Smog Lab Simulation
Indoor Air Pollution