Air ,Solid, Toxic, Hazardous, and Environmental Management Environmental Finals Flashcards
Of all the Earth’s natural resources, it is the most shared.
Air
moves throughout the atmosphere, connecting sources of pollution to
points of impact, often far apart.
Air
Three other features of air make it an unusually challenging resources to deal
with:
Air has traditionally not been viewed as a resource like water or land
resources, so there are no private or public claims on it.
Air does not obey geopolitical boundaries, so transboundary air pollution
problems are common and especially difficult to resolve.
Polluted ambient air cannot be remediated with technology.
Air
Earth’s atmosphere is about
100 miles deep.
Earth’s atmosphere is about 100 miles deep. It is mainly composed
mostly of
Nitrogen (78.1%), Oxygen (20.9%), and Argon (0.93%)
For comparison, carbon dioxide now makes up over——-of the
atmosphere.
0.039%
cause the release of many different
compounds into the air at concentrations that are high enough to
cause adverse impacts on human health, crops and other vegetation,
building materials, climate, and even habitants of aquatic
ecosystems.
anthropogenic activities
determine how air contaminants are
dispersed and move through the troposphere.
Weather patterns
Air pollution problem involves three parts:
the pollution source
- the movement or dispersion of the
pollutant - the recipient
Along with gas, the air we breathe is filled with suspended
solids and liquids called—–that come from a variety of
sources.
aerosols
circulate the same way the air in the troposphere
circulates.
Pollutants
caused by solar radiation and the irregular
shape of the earth and its surface, which causes unequal
absorption of heat by the earth’s surface and atmosphere.
Air movement
the——of the earth’s atmosphere also
yields differences in barometric pressure.
dynamic thermal system
involves both control of air pollution
sources and
Air quality management
is associated with both hot and cold weather
fronts.
Low-pressure systems
Air movement around low-pressure fronts in the Northern Hemisphere
counterclockwise
Air movement around low-pressure fronts in the Northern Hemisphere is
counterclockwise and vertical winds are——where condensation
and precipitation take place.
upward,
affected by the rotation of the rotation of earth of its axis
global air circulation
located
in the top right corner
of each data map
shows the general
wind direction and
speed for each
sampling period.
wind rose
❖The circular format of the wind rose shows the direction the winds blew from and the
length of each—–around the circle shows how often the wind blew from that
direction.
“spoke”
impacts from air pollution include increased
mortality rates, increased health care costs, decreased productivity,
and decreased quality of life.
Primary public health
has several defenses against air pollution
particularly large particles. When someone is breathing particle-
contaminated air, the human respiratory system works a bit like a
sieve, preferentially removing certain size fractions at various
stages.
respiratory system
is a nonuniform combination of different
compounds.
Particulate matter (PM)
All particles 10 μm and less in diameter are denoted
as
PM10..
All particles 2.5 μm and less in diameter are denoted as
PM2.5.
can travel deeper into the respiratory
system.
smaller particles
are trapped in the upper respiratory system, producing
a clogged nose and scratchy throat.
Larger particles
(those with diameter less than 0.1 μm) may actually
pass with air through the alveoli and incorporated into the bloodstream
and may affect many organs.
Ultra fine particles
defenses is to mobilize white blood
cells to metabolize foreign objects.
cardiovascular system’s
Accounting for all other risk variables,
it has been observed that ———— in air results in more heart
attacks. The connection may be the ultra fine particles.
increased PM
low-level burning of the respiratory surface tissues results in several
adverse outcomes, from breathing difficulty to respiratory failure. Ozone is one
pollutant that causes considerable irritation.
Irritation
arises from the introduction of pollutants into the cell. Ultrafine
particles contribute to these diseases.
Cell Damage
pollutants can trigger a release of histamines to fight the invader,
resulting in breathing difficulty and irritation of sensitive issues (e.g. skin, eyes).
Pollens cause these effects.
Allergies
pollutants permanently scar the tissues of the respiratory system,
resulting in increased breathing difficulty and often death. Asbestos is a pollutant
that causes this disease.
Fibrosis
pollutants can trigger abnormal, malignant tissue growth that
leads to cancer. Many hazardous air pollutants are cancer-causing.
Oncogenesis
*In the context of engineering analyses of air
quality, two (2) distinct systems are of interest:
➡ the outdoor environment (ambient air)
➡ indoor environment
➡The two layers closest to Earth’s surface are our primary
interest:
the troposphere and the stratosphere.
(tropos being Latin for mixed) the air layer
closest to the surface and extending some 10 to 15 km in
altitude.
troposphere
(stratos is Latin for layered or stratified) it
is above the troposphere from about 15 to 50 km in altitude
is a layer with very little mixing.
stratosphere.
is where pollution from human and natural
activities is first emitted.
troposphere
has less overhead atmosphere, so it has
more intense radiation than the troposphere. This radiation,
much of it ultraviolet, creates photochemical reactions such
as the conversion of molecular oxygen (O2) into ozone (O3).
stratosphere
oxygen
02
ozone
03
- In the stratosphere, as elevation————–, its gets warmer
because ozone gases in the upper layer absorb intense
ultraviolet radiation from the sun.
increases
It
acts as a shield for life on Earth.
ozone layer
is only about three molecules for every 10million
molecules in the air. But it does a very important job.
ozone
it is like a———-the ozone layer absorbs bits of radiation
hitting Earth from the sun. Even though we need some of
the sun’s radiation to live, too much of it can damage
living things.
sponge,
absorbs bits of radiation
hitting Earth from the sun. Even though we need some of
the sun’s radiation to live, too much of it can damage
living things.
ozone layer
Operating at a regional scale are the regional transport processes
and appears on daily weather forecasts:
➡high-pressure system
➡low-pressure systems
Both are created from the interaction of ————masses
near the surface.
cold and warm air
are created when air that is warmed by
surface heating begins to rise.
Low-pressure systems
are typically created when air is
descending to the ground. The pressure systems thus have unique
vertical transport tendencies — upward for low pressure,
downward for high pressure.
High-pressure systems
upward
low pressure,
downward
high pressure.
Much of the human population resides
along the coast.
In fact, 21 of the world’s
———— are located in coastal areas,
and the average population density in
coastal areas is twice the global average.
33 megacities
Coastal locations are prone to additional
transport pattens created by the ————- and the resulting temperature
differences that develop due to the
differential heating that occurs.
land-sea
interface
can build as the air
slowly moves inland.
Pollutant concentrations
this situation exists when the atmospheric temperature
changes more dramatically with altitude than the temperature of the
air parcel that contains the pollutant (s).
Stable
this situation exists when the atmospheric temperature
changes less dramatically with altitude than the temperature of the
air parcel that contains the pollutant (s).
Unstable
the atmosphere exerts no force on pollutant emissions that
move vertically. This situation occurs when the temperature changes
for atmosphere and the air parcel containing the pollutant (s) are
nearly identical.
Neutral
General Stability Conditions Encountered in the Atmosphere:
stable, unstable, neutral
The US federal government, through the Environmental
Protection Agency (EPA), has identified six pollutants
of special concern:
- ozone-03
- particulate matter-PM
- sulfur dioxide-S02
- nitrogen dioxide-N02
- carbon monoxide-CO
- lead-Pb
Fuel combustion from vehicles and engines.
Reduces the amount of oxygen reaching the body’s organs and tissues; aggravates heart disease, resulting in chest pain and other symptoms.
Carbon Monoxide (CO
Secondary pollutant formed by chemical reaction of volatile organic compounds (VOCs) and NOx in the presence of sunlight.
Decreases lung function and causes respiratory symptoms, such as coughing and shortness of breath, and also makes asthma and other lung diseases get worse. More on Ground Level Ozone Here
Ground-level Ozone (03)
Smelters (metal refineries) and other metal industries; combustion of leaded gasoline in piston engine aircraft; waste incinerators (waste burners), and battery manufacturing.
Damages the developing nervous system, resulting in IQ loss and impacts on learning, memory, and behavior in children. Cardiovascular and renal effects in adults and early effects related to anemia.
Lead (Pb)
Fuel combustion (electric utilities, big industrial boilers, vehicles) and wood burning.
Worsens lung diseases leading to respiratory symptoms, increased susceptibility to respiratory infection
Nitrogen Dioxide (NO2)
this is formed through chemical reactions, fuel combustion (e.g., burning coal, wood, diesel), industrial processes, farming (plowing, field burning), and unpaved roads or during road constructions.
Short-term exposures can worsen heart or lung diseases and cause respiratory problems. Long-term exposures can cause heart or lung disease and sometimes premature deaths.
Particulate Matter (PM)
SO2 comes from fuel combustion (especially high-sulfur coal); electric utilities and industrial processes as well as natural occurrences like volcanoes.
Aggravates asthma and makes breathing difficult. It also contributes to particle formation with associated health effects.
Sulfur Dioxide (SO2)
are the amount of pollutant a source puts
into the air, usually over a fixed amount of time;
hence, emission rates are expressed as mass per
time.
Emissions
expressed as mass per
time.
emission rates
depend on the source,
pollutant, and problem of interest, but common units are
g/s, kg/day, and tonnes/yr. In a few places, tons/day
and lb/ hr might still be used.
Typical emission rate units
can be highly variable
- Emission rates .
6 classifications of air emissions
- Specific pollutant
- Type of source
- Natural processes
- Permitted Emissions
- Fugitive emissions
- Accidental emissions
impacts usually specific to a particular
pollutant, as are emission reduction strategies. The criteria
pollutants receive the most attention.
- Specific pollutant
One critical classification is whether the
source is stationary sources, mobile sources, or point
sources.
- Type of source
in some areas, natural emissions may
dominate the total for certain pollutants, and in these cases,
there will be little impact from engineered emission-control
strategies.
- Natural processes
s
- are those granted by an agreement
with the state air resource regulatory agency. Another
important emission classification scheme, particularly to
industry, is whether an emission is permitted, fugitive, or
accidental.
- Permitted Emissions
pollutant releases from an unconfined
source. These sources are often area sources and outdoors.
- Fugitive emissions
release due to accidents or poor
operation and maintenance of equipment. Most of these
emissions are best controlled by diligent maintenance of
equipment, including ducts, valves, and storage vessels.
- Accidental emission
Four methods are used to quantify the magnitude of air
pollutant emissions:
1.Direct measurements
2.The mass balance approach
3.Process modeling
4.Emission factor modeling
this poses several unique challenges,
and the sampling occurs in the stack discharge airstream.
1.Direct measurements
it can be used to indirectly
determine the emission rate from some sources.
2.The mass balance approach
this attempt to describe emissions as
mathematical functions of relevant process information.3.Process modeling
4.Emission factor modeling
3.Process modeling
it relates the air pollution released
by a source activity to the magnitude of that activity. The
proportionality between emissions and activity is called an
emission factor.
4.Emission factor modeling
The
proportionality between emissions and activity is called an
emission factor.
- Limiting emissions into the air is both technically
.
difficult and expensive
are the only air cleaning
mechanisms available, and neither is very efficient,
good air quality depends on pollution prevention and on
limiting what goes into the air.
rain and deposition
may be realized in a
number of ways.
control of air emissions
There are five (5) options to control air pollution:
- Prevention
- Regulatory solutions
- Market-based solutions
- Voluntary solutions
- Emission-control technologies
There are five (5) separate possibilities for
control of air emissions:
- Source correction
- Collection of Pollutants
- Cooling
- Treatment
- Dispersion
Changing or eliminating a process that produces a polluting
air effluent is often easier than trying to trap effluent.t.
Source correction
- Processes may also be modified in order to reduce air
pollution.
Source correction
mandates the use of oxygenated
fuels in urban areas in order to limit CO emissions from
automobiles.
The 1990 Clean Air Act
Such measures as process change, raw material
substitution, and equipment modification to meet emission
standards are known as
controls.
is the term used for all devices and methods for
decreasing the quantity of pollutant reaching the
atmosphere, once it has been generated by the source.
Abatement
is often the
most serious problem in air pollution control.
Collection of pollutants for treatment
is a notorious polluter mainly
because the effluent (exhaust) is so difficult to trap and
treat.
Automobile exhaust
is one means of control.
Many stationary industries recycle exhaust gases,
usually CO and volatile organic compounds, as for the
process.
Recycling of exhaust gases
- The exhaust gases to be treated are sometimes too hot for
the control equipment, and must be cooled.
cooling
may also drop the temperature below
condensation point of some pollutants, so they may be
collected as liquids.
cooling
are all
acceptable cooling methods.
Dilution
quenching,
heat exchange
are probably the most widely used cooling
method and are especially appropriate where heat can be
conserved.
Cooling coils
requires matching the
characteristics of the pollutant with features of the
control device.
Selection of the treatment device
vary in size over many orders of
magnitude, from ideal gas molecules to macroscopic
particles several millimeters in diameter.
Pollutant particles
The various air pollution control devices
are conveniently divided into those that
control particulate matter and those that
control gaseous pollutants. Some of
this are the following:
Cyclones
Fabric Filters
Wet Collectors/Scrubbers
Electrostatic Precipitators
HEPA Filters
is a popular,
economical, and effective means
of controlling particulates. They
alone are generally not adequate
to meet stringent air pollution
control regulations, but serve as
pre cleaners for control devices
like fabric filters or electrostatic
precipitators.
Cyclones
are used for controlling particulate matter operate like
a vacuum cleaner. Dirty gas is blown or sucked thorough fabric filter
bag.
Fabric Filters
the spray tower or scrubber
can remove larger particles
effectively. More efficient
s c r u b b e r s p r o m o t e t h e
contract between air and water
by violent action in a narrow
throat section into which the
water is introduced.
Wet Collectors/Scrubbers
are widely used to trap fine particulate
matter in applications where a large amount of gas needs treatment and
where use of a wet scrubber is not appropriate. Coal-burning electric
generating plants, primary and secondary smelters, and incinerators often
used this.
Electrostatic Precipitators
very hazardous or
toxic particulate matter of diameter
less than 1 μm must sometimes be
controlled to better than 99.9%. A
single stage of High Efficiency
Particulate Attenuation (HEPA)
micropore or glass frit filters, through
which the pre cleaned gas is forced
or sucked by vacuum, can achieve
this level of control, and four to six
HEPA filter stages in series can
achieve 99.9999% control. HEPA
filters are used to control emission
of radioactive particles.
HEPA Filters
(HEPA)
High Efficiency
Particulate Attenuation
is the process by which contaminants move through the
air and a plume spreads over a large area, thus reducing the
concentration of the pollutants it contains.
Dispersion
The plumes spreads both
horizontally and vertically.
spreads both horizontally and vertically.
The plumes
The most commonly used model for the dispersion of gaseous air
pollutants
Gaussian model developed by Pasquill,
in which
gases dispersed in the atmosphere are assumed to exhibit ideal
gas behavior.
Gaussian model developed by Pasquill,
Many atmospheric factors influence the way air pollution is
dispersed,
- Many atmospheric factors influence the way air pollution is
dispersed, including
wind direction and wind speed, type of
terrain and heating effects.
To better understand how atmosphere processes can affect
ground level pollution, can be——————-
described simply as either stable or unstable, where the
stability is determined by wind (which stirs the air) and
heating effects (which cause convection currents).
atmospheric conditions
is determined by wind (which stirs the air)
stability
is determine by which cause convection currents
heating effects
The processes by which the atmosphere cleans itself do
exist, and includes the effect of gravity, contact with the
earth’s surface, and removal by precipitation.
DISPERSION
particles in the air, if they are larger than
about a millimeter in diameter, are observed to settle out
under the influence of gravity.
➡ Effect of Gravity
many atmospheric gases are
absorbed by the features of the earth’s surface, including
stone, soil, vegetation, bodies of water and other materials.
Soluble gases like SO2 dissolve readily in surface waters.
Surface Sink absorption
it removes contaminants from the air by
two methods.
Precipitation
is an “in-cloud” process in which very small
pollutant particles become nuclei for the formation of rain
droplets that grow and eventually fall as precipitation.
*Rainout
is a “below-cloud” process in which rain falls
through the pollutant particles and molecules, which are
entrained by the impinging rain droplets or which actually
dissolve in the rainwater.
*Washout
is transferred from the earth’s surface by radiation,
conduction, and convection.
- Heat
masses heat and cool faster than water
land
is measured as wind velocity.
- Horizontal wind motion
are plotted as a wind rose, a graphic
picture of wind velocities and the direction from which the
wind came.
Wind velocity data
As a parcel of air in the earth’s atmosphere rises
through the atmosphere, it experiences decreasing
pressure and thus expands.
VERTICAL DISPERSION OF POLLUTANTS
The rate at which dry air cools as it rises is called
dry adiabatic lapse rate
is independent of the ambient air
temperature.
dry adiabatic lapse rate
These includes paper and plastic
generated at home, ash produced
by industry, cafeteria food wastes,
leaves and cut grass from parks,
hospital medical wastes, and
d e m o l i t i o n d e b r i s f r o m a
construction site.
๏Solid wastes
These materials are considered a
——– when owners and society
believe they no longer have value.
waste
varies
g reatly between cultures and
countries and has evolve over time.
Solid-waste management
differ from liquid or gaseous wastes
because they cannot be pumped or flow like fluids.
๏Solid wastes
can be placed into solids forms
(including soils) and thus can be contained more
easily.
๏Solid wastes
Proper management of solid wastes has
four main objectives:
1.Protect public health
2.Protect the environment (including diversity)
3.Address social concerns (equity, environmental
justice, aesthetics, risk, public preferences,
recycling, renewable energy)
4.Minimize cost
*Preindustrial communities arranged to have solid waste
collected and disposed of in central locations termed
middens.
when it increased, solid waste became more of a problem. Some
wastes were left in streets and alleys, feeding dogs,
pigs, and rats.
population, urbanization, and consumption
*During the 1900s, increased industrialization resulted in
the production of different wastes —
more hazardous
solid wastes.
*Non recovered solid wastes were placed into engineered
facilities
engineered or sanitary landfills.
In the past twenty years, there has been an increased
emphasis on———–as part of the pollution prevention.
reduction, reuse and recycling ( the
three Rs)
Solid wastes other than hazardous and radioactive
materials are considered as————and consist of all the solid and semisolid
materials discharged by the community.
municipal solid waste
(MSW)
The solid wastes jointly managed by a municipality
are
municipal solid waste
(MSW)
The fraction of MSW produced in domestic
households is called
refuse.
The components of refuse are:
garbage or food wastes
rubbish - including glass, tin cans, and paper
trash - including larger items like limbs, old
appliances, and pallets that are usually deposited
in garbage cans
depends on both the
characteristics of the site and the characteristics
of the MSW itself.
Refuse management
The following are characteristic of MSW:
1)Gross composition
2)Moisture content
3)Particle size
4)Chemical composition
5)Density
it can be the most
important characteristic affecting MSW
disposal, or the recovery of materials and
energy from refuse.
Gross composition
is expressed either “as
generated” or “as disposed”, since moisture
transfer takes place during disposal process.
Refuse composition
of MSW may vary between
15 and 30%, and is usually about 20%.
2.Moisture content
is particularly
important in refuse processing for resource
recovery.
3.Particle size distribution
the use of both
proximate and ultimate analysis in the
combustion of MSW and its various fractions
4.Chemical composition
Wastes that spreads disease are termed
putrescible
wastes.
They can spread disease———– (as in the case of
dirty diapers),
directly
or———– by providing a food
source for disease vectors such as insects (flies) or
animals (rats, dogs, birds).
indirectly
Some solid wastes (Ex. mining wastes and most
agricultural and industrial wastes) are managed by
the
waste generator.
Smaller sources are usually managed jointly under
one integrated system.
Sources of Solid Waste that Makes Up MSW:
Residential
Commercial
Institutional
Construction and Demolition
Municipal services
Industrial
Agricultural
Mining
Main sources of waste according to a research
entitled “Recycling of Organic Wastes for Biomass
Energy Production in Green Buildings”, Dec. 2016
industrial
irrigation
domestic/residential
public supplied industrial, commercial
mining
Sources of Solid Wastes that Makes Up MSW:
➡Residential
➡Commercial
➡Institutional
➡Construction and Demolition
➡Municipal services
➡Industrial
➡ Agricultural
➡Mining
are some of the major source of solid waste.
Garbage from these places include food wastes,
plastics, paper, glass, leather, cardboard, metals,
yard wastes, ashes and special wastes like bulky
household items like electronics, tires, batteries, old
mattresses and used oil.
➡Residential and homes where people live
commercial buildings and facilities
refer to hotels, markets, restaurants, go downs,
stores and office buildings. Some of the solid wastes
generated from these places include plastics, food
wastes, metals, paper, glass, wood, cardboard
materials, special wastes and other hazardous waste
➡Commercial buildings and facilities
these schools, colleges, prisons, military
barracks and other government centered that also
produce solid waste. Some of the common solid
wastes obtained from these places include glass,
rubber waste, plastics, food wastes, wood, paper,
metals, cardboard materials, electronics as well as
various hazardous wastes.
➡Institutional
these sites include
new construction sites for buildings and roads, road
repair sites, building renovation sites and building
demolition sites. Some of the solid wastes produces
in these places include steel materials, concrete,
wood, plastics, rubber, copper wires, dirt and glass.
➡Construction and Demolition
the urban centers also contribute
immensely to the solid waste crisis in most countries
today. Some of the solid waste brought about by the
municipal services includes street cleaning, wastes
from parks and beaches, wastewater treatment plants,
landscaping wastes and wastes from recreational areas
including sludge.
➡Municipal services
they are known to be one of the biggest
contributors of solid waste. They include light and
heavy manufacturing industries, construction sites,
fabrication plants, canning plants, power and chemical
plants. These industries produce solid wastes in form of
housekeeping wastes, food wastes, packaging wastes,
ashes, construction and demolition materials, special
wastes, medical wastes as well as hazardous wastes.
➡Industrial
crop farms, orchards, dairies,
vineyards and feedlots are also sources of solid
wastes. Among the wastes they produce include
agricultural wastes, spoiled food, pesticide
containers and other hazardous materials.
➡ Agricultural
from coal mining, uranium metal
mining, oil/gas exploration. Some of the solid
wastes produced are vast amounts of solid waste
needing specialized management.
➡Mining
The quantities of MSW generated in a
community may be estimated by one of three
techniques:
- Input analysis
- Secondary data analysis -
- Output analysis -
- estimates MSW based on
use of a number of products.
- Input analysis
may be used to
estimate solid waste production by some
empirical relationship.
- Secondary data analysis -
should be measured by
weighing the refuse dumped at the disposal
site, either with truck scales or with portable
wheeled scales.
- Output analysis -
The amount of generated MSW can vary within a
year , b e t w e e n u r b a n a n d r u r a l a r e a s ,
geographically, with income, and among
countries.
Quantities of Municipal Solid Waste
One key is to understand the differences between
generation rates and discard rates (the difference
being the part of the waste stream that is reused or
recycled).
Wastes are considered ———- when they
pose a direct threat to human health or the
environment.
hazardous waste
Waste can be classified as hazardous by one of six
characteristics:
1) Ignitable
2) Corrosive
3) Reactive
4) Toxic
5) Radioactive
6) Infectious
-Can the waste create a fire (e.g., waste solvent)?
Ignitable
-Is the waste very acidic or basic and so able to corrode storage
containers (e.g., battery acids)?
2) Corrosive
