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Pollution
Pollution definition
Pollution can be defined as a process of making air, water ,soil etc dangerously dirty and not suitable to use.
Any substance introduced into the environment that adversely affects the usefulness of a resource.
Why does pollution happen?
Pollution happens because no process is 100% efficient.
No natural or human process, such as manufacturing or fuel burning,
is100% efficient. Each process produces pollution or waste and waste
energy. Carelessness or poor technology aggravates the amount of
pollution produced, as do poorly designed processes.
Understanding Environmental Pollution(2004)
Page 3
Pollutant sources
Motor vehicles including cars, buses, airplanes, ships, and off-road vehicles.
Chemical and petroleum refineries. Manufacturing facilities.
Commercial operations such as bakeries, and garages.
Plants that generate electric power by burning coal, oil, or natural gases.
Agricultural operations.
Mining operations.
Military operations.
Forestry operations.
Construction and road building.
OthersUnderstanding Environmental Pollution(2004)
Page 4
Types Of Pollution
Freshwater pollution and scarcity
Air pollution (especially ozone, fine particles)
Global warming
Acid deposition
Municipal-solid-waste generation
Hazardous-waste generation
Increasing energy use
New threats: nitrogen-fertilizer and heavy-metal pollution
Compiled from: United Nations Environmental Program (UNEP) report
Page 5
High-risk threats to human health
Drinking-water pollution
Heavy air pollution, outdoors and indoors
lack of basic sanitation
According to the World Health Organization (WHO).
Page 6
Introduction
Modern urban development in the 20th century has focused on the use of motor vehicles and migration of people from rural areas to cities and suburbs.
During the last decade, the travel demand on the road infrastructure has increased more than its capacity.
This will lead to accelerated consumption of petroleum and degradation of air quality.
Article: The Influence of Road Infrastructure and Traffic on Soil, Water, and Air Quality(2003)
Page 7
Criteria air pollutants
Carbon monoxide
Ozone
Sulfur dioxide
Nitrogen oxides
Particulate matter(PM)
Lead
Combustion, especially fossil fuel combustion produces all six criteria pollutants.
Understanding Environmental Pollution(2004)
Carbon monoxide
it is a product of incomplete combustion of carbon-containing material.
Produced by combustion of fossil fuel and biomass.
The US ambient air standard for CO is 9 ppm averaged over 8 hours;
Sources of carbon monoxide In urban areas, up to 80 or 90% of CO is emitted by motor vehicles.
Cigarette smoke
Facilities burning coal , natural gas are CO sources.
Atmospheric oxidation of methane gas and other hydrocarbons
Understanding Environmental Pollution(2004)
Why carbon monoxide is of concern
Even levels of CO found in city traffic can aggravate heart problems.
CO can cause headache, dizziness, fatigue, and drowsiness .
At higher doses, such as found in enclosed spaces with improperly operating combustion appliances CO may lead to coma and death.
Reducing carbon monoxide emissions Oxygen-containing fuel additives are added to gasoline in some US cities to
enhance burning in winter, when engines run less efficiently.
Facilities burning fossil fuels or wood are required to maintain high burning efficiencies to reduce emissions.
Many places prohibit open burning of trash and garbage.
Understanding Environmental Pollution(2004)
summer sunlight stagnant air
Ozone
Ozone (O3) has three oxygen atoms.
Ground-level O3 is the same O3 that is found in the stratosphere.
O3 is much more reactive than O2.
Sources of ozone
summer temperature
Understanding Environmental Pollution(2004)
Why care about ozone? O3 is much more reactive than O2. The EPA considers O3 the most serious and persistent
air quality problem in the United States.
Effects on people
Effects on plants and trees
Reducing ground-level ozone
we cannot reduce ground-level O3 unless we reduce NOx and VOCs emissions.
In the early twenty-first century the United States has a new O3 standard
Reducing other NOx and VOC sources .
Understanding Environmental Pollution(2004)
Sulfur dioxide
Sulfur dioxide (SO2) is a colorless gas with a sharp irritating odor.
Sources of sulfur dioxide
Sources of solfur dioxide
Electric power plants
Fuel burning
Indusrial sources
Other
Transportation
67%15%
7%8%
3%
Why care about sulfur dioxide? Direct exposure to the gas, SO2
Aerosol effects
Major environmental effects of aerosols.
Reducing SO2 emissions
With increasingly strict controls
Power plants can cut SO2 emissions in several ways.
1.One is to burn coal with low sulfur content.
2. effective technologies exist to capture the SO2 formed.
3. uses market incentives.
Understanding Environmental Pollution(2004)
Page 14
Nitrogen oxides
The gases, nitric oxide (NO) and nitrogen dioxide (NO2) are the major
components of nitrogen oxides
A third gas, nitrous oxide (N2O) is also often grouped into NOx.
Why care about NOx? NOx has two distinctive and very important effects not shared with sulfate and
sulfuric acid. These are:
NOx gases are precursors of ground-level O3 whereas SO2 is not.
Deposited to Earth or water, the nitrogen in nitrate and nitric acid is a major plant nutrient. It can benefit plant life, but high concentrations have adverse, even devastating, consequences.
Understanding Environmental Pollution(2004)
Page 15
NOx sources
Reducing NOx emmision NOx is harder to control than SO2, which is formed from sulfur present in
the fuel
Emissions of NOx peaked at about 25 million tons (22.7 million tonnes) in 1990, and were still 24 million tons (21.8 million tonnes ) in 1998.
Sources of nitrogen oxides
Transportation
Electric power plants
Others
Indusrial sources
Fuel burning25%
5%
12%
5%
53%
Understanding Environmental Pollution(2004)
Page 16
Particulate matter
As the name particulate matter ( PM ) implies, PM is solid , albeit the particles may be very fine aerosols PM accounts for about 10% of US air pollution. PM is a confusing pollutant.
Composition varies.
Size varies greatly.
Other pollutants can become PM.
Sources of PM10 and PM2.5 The major source of PM10 is dust from farms, mines, or from roads, unpaved
and paved.
Conversely, most PM2.5 does originate from combustion, especially diesel motor vehicles, electric power plants, and Industrial operations.
Locales with large numbers of wood-burning stoves,which often inefficiently
Construction sites release large amounts of dust.
Understanding Environmental Pollution(2004)
Page 17
Why care about PM?
Human effects
Absorbed into the bloodstream and exert systemic effects elsewhere
Deeply inhaled, they reach and can inflame the lung’s alveoli
lung cancer
Environmental effects.
PM strongly contributes to the haze or smog seen in many cities.
Reducing PM emissions
In 1997, the US EPA set new standards for particulates
The old PM10 standard was 50 μg/m3 of air; this standard is retained. However to this was added a new PM standard specific to PM 2.5 of 15 μg/m3.
By now it is probably clear that controlling combustion sources producing PM is a major need.
Understanding Environmental Pollution(2004)
Page 18
Lead
In the 1970s, when the EPA designated it a criteria air pollutant, lead was still added to gasoline in the United States, incinerators were less well controlled than today , and lead emissions in general were less well controlled. Today, most lead emissions have been eliminated or are well controlled. Lead emissions from coal-burning power plants are an exception.
However, a separate set of lead-related problems exist. Lead mobilized into the environment many years ago, remains a significant pollutant today . It is in the paint of houses built before the late 1970s, in the solder of old water pipes, and in roadside soil contaminated with lead from car exhaust . Leaded gasoline is still used in a number of less-developed countries ; so is leaded tableware. Recycling of lead-acid batteries in impoverished countries remains an occupational exposure even for children .
Understanding Environmental Pollution(2004)
Page 19
Volatile organic chemicals
A great many organic chemicals are volatile; that is, they can evaporate.
These fall into the category of ‘‘volatile organic chemicals”
Why care about VOCs? VOCs contribute to the formation of ground-level ozone. many drivers
and pedestrians develop headaches and other symptoms if heavily exposed to volatile hydrocarbons in motor vehicle exhausts.
Page 20
VOC sources
Combustion sources.
Non-combustion sources.
Natural sources.
Reducing VOC emissions By 1985, VOC emissions had dropped about 30% compared with 1970 in
the United States. This was presumably due to regulations enacted in the 1970 Clean Air Act (CAA) and its 1977 amendments. In 1990, CAA amendments mandated further reductions in motor vehicle emissions.
Page 21
Hazardous air pollutants
Commonly called ‘‘toxic air pollutants,” HAPs include 188 chemicals specified as hazardous in the 1990 US Clean Air Act Amendments ; About 70% of HAPs are also VOCs; that is, volatile organic chemicals , whereas many others are metals.
Types And Sources of HAPs Benzene :Gasoline, cigarette smoke
Toluene :Gasoline, vehicle exhaust, smoking, paints
Ethylene glycol : Automobile antifreeze, brake fluid
Methanol :Windshield antifreeze, solvent
Page 22
Other pollutants from road traffic
The main processes by which vehicles disseminate pollutants into the environment are combustion processes , the wear of cars (engine, tires, brakes) leaking of oil and coolants, and corrosion. Lead and PAHs are released in combustion processes, zinc is derived from tire dust (zinc is a catalyst used in the manufacture of tires), and copper is derived from the corrosion of radiators and brakes; the other heavy metals have mixed origins.
Article: The Influence of Road Infrastructure and Traffic on Soil, Water, and Air Quality(2003)
Page 23
Reducing Air Pollution
Using legislation
Inspection and maintenance
Low-emission and zero-emission vehicles
Government action
Use internet and other electronic devices
Modifying vehicles for better fuel economy
Alternative fuels
Traffic management
Page 24
Requirements on the fuel of tomorrow
Any new fuel must be just as safe, reliable and easy to obtain and handle
It must be possible to produce it in adequate quantities
Low carbon content
And finally it must be possible to produce it at commercially acceptable costs and be available throughout the world.
In Germany the “Transport Energy Strategy” (TES) project group has looked at 10 potential alternative fuel types and over 70 ways of producing them.
The TES found that hydrogen met these criteria to the best possible effect.
En route to a hydrogen infrastructure for road traffic(2006)
Page 25
Advantages
Air pollutants emissions can be reduced.
much lower price fluctuations can be expected.
The result of its combustion is water.
Hydrogen is non-toxic (like methanol)
highly flammable and therefore eminently suitable for thermal processes
En route to a hydrogen infrastructure for road traffic(2006)
Page 26
Traffic management
Traffic management refers primarily to measures that address traffic congestion . These range from installing traffic signals , introducing one-way roads and improving parking facilities , to coordinating different transportation modes , such as introducing separate bus lanes.
Conversely , the removal of bottlenecks also leads to increased traffic flow, greater kilometers traveled and hence , increase emissions. In order to prevent such an outcome , a restricted-access policy might be implemented: curbing parking in specific zones , road-pricing systems or levying toll at the entry of specific zones .
Urban Air Quality Management Strategy(1997)
Page 27
Introduction
Water is one of the most important commodities which Man has exploited than any other resources for sustenance of his life . Most of the water on this planet is stored in oceans and ice caps which is difficult to recovered for our diverse needs . Most of our demand is fulfilled by rain water which get deposited in surface and ground water resources. Pollution of water has emerged as one of the most significant environmental problems of the recent times . Not only there is an increasing concern for rapidly deteriorating supply of water but the quantity of utilizable water is also fast diminishing. The causes of such a situation may be many, but gross pollution of water has its origin mainly in urbanization , industrialization , agriculture and increase in human population observed in past one and a half century .
water pollution , causes , effects and control(2006)
Page 28
What is pure water?
It can be said that no water is pure or clean owing to the presence of some quantities of gases , minerals and life . However , for all practical purposes , a pure water is considered to be that which has low dissolved and suspended solids and obnoxious gases as well as low in biological life . such a high quality of water may be required only for the drinking purposes , while for other uses like agriculture and industry , the quality of water can be quite flexible and water polluted up to certain extent , in general sense can be regarded as pure.
water pollution , causes , effects and control(2006)
Page 29
What is polluted water?
Water can be regarded polluted when it gets changed in its quality or composition either naturally or as a result of human activities so as to become less suitable for drinking , domestic , agricultural , industrial , recreational , wildlife and other uses for which it would have been otherwise suitable in its natural or unmodified state.
water pollution , causes , effects and control(2006)
Page 30
Pollution Resources
A ‘‘point source” is ‘‘any single identifiable source . . . from which pollutants are discharged, e.g., a pipe, ditch, ship, or factory smokestack.”
Outlet pipes of industrial facilities wastewater-treatment plants are
examples of point sources.
Developed countries such as the United States initially worked to control point sources of water pollution.
water pollution , causes , effects and control(2006)
Page 31
Pollution Resources
A ‘‘non-point-source” pollutant is one whose source is much harder to
identify precisely, hence the term ‘‘non-point”.
Atmosphere(dust storms , air pollution , volcanic dust , fires , etc)
Animal waste
Underground rocks and volcanoes
water pollution , causes , effects and control(2006)
Page 32
Pollution Resources
The word ‘‘runoff” indicates rainwater or snowmelt carried across land to
water. Runoff arises from non-point sources. Runoff carries almost
anything that water can carry oil, grease, dirt, trash, animal waste,
microorganisms , and chemical pollutants, including metals, pesticides,
and fertilizers.
water pollution , causes , effects and control(2006)
Page 33
Water pollutant
Pollutants regulated by the US Clean Water Act are described here.
conventional
non-conventional
toxic
Understanding Environmental Pollution(2004)
Page 34
Conventional pollutants
Biochemical oxygen demand
PH
Nutrients
Suspended solids
Oil and grease
Understanding Environmental Pollution(2004)
Page 35
Priority (toxic) pollutants
The US EPA, under the Clean Water Act, regulates 126 priority pollutants including metals such as arsenic, cadmium, lead, mercury ,nickel, copper, and zinc. These metals are not only priority water pollutants .They are also HAPs.
If the priority pollutant comes from a point source, e.g., a wastewater-treatment facility, it can usually be well controlled. Control is more difficult for priority pollutants found in non-point-source runoff, as with pesticides from agricultural fields, organic chemicals in runoff from city streets , etc.
Understanding Environmental Pollution(2004)
Page 36
Non-conventional and non-toxic pollutants
A third group of water pollutants regulated under the Clean Water Act is the non-conventional and non-toxic pollutants. Here we find ammonia, chloride (as from sodium chloride, salt), iron, aluminum, total phenols, and color. Many facilities textile factories are an example discharge colored effluents. The intensity of the discharged color is regulated by law. Heat is a regulated pollutant too. Electric power plants especially, but also many industrial facilities discharge heated effluents.
Understanding Environmental Pollution(2004)
Page 37
Reducing point-sources
Wastewater treatment
Large quantities of primary and secondary sludge result from wastewater treatment.
In the United States, 60% of treated sludge is applied to farms, forests, parks, and golf courses as fertilizer.
Sludge produces gaseous amines and contains pathogens, metals, and organic chemicals
In the United States, the US National Research Council reviewed the way that sludge was being handled, and proposed more research aimed at developing new standards.
Understanding Environmental Pollution(2004)
Page 38
Reducing point-sources
Industrial wastewater
In earlier years, industrial facilities often paid a municipal facility to treat their wastewater effluent along with municipal wastewater. This was financially attractive to municipal plants except that some industrial effluents had components that interfered with their proper functioning; or the municipal plant could not remove certain noxious pollutants and they passed into receiving waters. Municipalities often want to use wastewater sludge for beneficial purposes, and the presence of industrial pollutants can make that impossible. So, the US EPA began requiring industrial plants to pre-treat their wastewater before sending it to a municipal plant. Alternatively, some industrial facilities completely treat their ownwastewater
Understanding Environmental Pollution(2004)
Page 39
Alternative wastewater treatments
Small communities with land available sometimes use artificial (constructed) wetlands.
Recently, the French added chrysanthemums to the mix of plants in constructed wetlands.
Moreover, the chrysanthemums can be harvested and processed to obtain the natural insecticide pyrethrin, which is in high demand.
Understanding Environmental Pollution(2004)
Page 40
Reducing non-point sources
Reducing non-point-source pollution is much more difficult than
reducing point-source pollution.
Construction sites (Contaminants include soil, oil/grease,heavy metals, debris)
Build settlement (detention) pond to trap runoff
Put hay dam or fabric fence around the site
Mining operations (Contaminants include acid soil, metals)
Grow vegetation on sites to retain soil and pollutants,
For strip mines, restore polluted water and damaged land
Understanding Environmental Pollution(2004)
Page 41
Reducing non-point sources
In 1985, European countries decided to reduce the excessive amounts
of the nutrients phosphorus and nitrate running off into the Rhine
River. They set a goal of reducing the amount of each nutrient reaching
the Rhine by 50% within 10 years. They succeeded with phosphorus
because it largely came from point sources wastewater(sewage)treatment
plants. However, as you will see below, nitrate enters water
bodies largely in non-point-source runoff. This is harder to trace
and control. As of 2000, the desired 50% reduction in nitrate still
was not achieved.
Understanding Environmental Pollution(2004)