Environmental Eng. 1 (CE 360)
Dr. Sameh S. Ahmed
Associate Professor of Environmental Eng.
Civil Engineering Department
Engineering College
Majma’ah University
s.mohamed@mu.edu.sa
faculty.mu.edu.sa/smohamed/SaMeH
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Chapter 2
Environmental Problems
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Environmental Pollution
Definition (1): Any condition
or substance resulting from human
activity that affects the quality of
the environment.
Definition (2): Environmental
pollution is the unfavorable
alteration of our surroundings,
resulting largely or wholly as a byproduct of man’s actions.
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Environmental Problems
The environmental problems can be classified as:
(1) Local and immediate problems, such as water pollution
arising out of municipal or industrial wastes, air pollution
due to auto-mobiles and industries, noise pollution, etc.
(2) Regional problems, both immediate and long term such
as acid rain, dumping, and poisoning of the environment by
toxic wastes, deforestation, soil erosion, destruction of habitat,
etc.
(3) Global environmental problems, like green houses effect,
ozone layer depletion, etc.
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Exchanges and Interactions of Pollutants
Inhabitation phytoplankton
Changing in (plant life)
Septic gasses
Co-production
Absorption
Gravity
Disposal of Air
Pollution
Rain
Air
Disposal of Water
Contamination
Water
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Exchanges and Interactions of Pollutants
Entrainment
Decomposition
Reaction
Gravity
Disposal of Air
Contaminants
Rain
Air
Disposal of
Solid Waste
Land
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Exchanges and Interactions of Pollutants
Acid mine drainage
Leaching
Disposal of
Water
Contamination
Incorporation into
sediments
Water
Disposal of Solid
Waste
Land
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2.3 Pollution Control Methods
1. Applicable to all emissions
(i) Decrease or eliminate production of emissions
• Change specifications of product
•
•
•
•
Change the design of product
Change process temperature, pressure or cycle
Change specifications of materials
Change the product
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Pollution Control Methods (cont.)
1. Applicable to all emissions
(ii) Confine the emissions
–
–
–
Enclose the sources of emissions
Capture the emission in an industrial exhaust
system
Prevent drafts
(iii) Separate the contaminant from effluent gas
– Scrub with liquid
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2.3 Pollution Control Methods
2. Applicable specifically to Particulate Emissions
(i) Decrease or eliminate particulate of emissions
– Change from solid to liquid or gaseous material
– Change from dry to wet solid material
– Change particle size of solid material
– Change to process that does not require particulate
material
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Pollution Control Methods (cont.)
2. Applicable specifically to Particulate Emissions
(ii) Separate the contaminant from effluent gas
stream
–
–
–
–
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Gravity separator
Centrifugal separator
Filter
Electrostatic precipitators
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2.3 Pollution Control Methods
3. Applicable Only to Gaseous Emissions
(i) Decrease or eliminate gas or vapor production
•
Change to process that does not require annealing, baking,
boiling, burning, casting, cooking, dehydrating, dipping,
distilling, expelling, melting, pickling, plating, reduction,
roasting, smelting, etc.
• Change from liquid or gaseous to solid material
• Change to process that does not require liquid or gaseous
material
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Annealing
Casting
Roasting
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Pollution Control Methods (cont.)
3. Applicable only to Gaseous Emissions
(ii) Burn the contaminant to
CO2 and H2O
Incinerator
Catalytic burner
Incinerator
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2.3 Pollution Control Methods
3. Applicable Only to Gaseous Emissions
(iii) Adsorb the contaminant
• Activated carbon
increase the surface area available for adsorption or chemical
reactions
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3.3 Methods of Expressing Concentration
The two methods expressing the concentration of a
constituent of a liquid or gas are:
• Mass/volume: the mass of solute per unit volume of
solution (in water chemistry). This is similar to weight
per unit volume; typically mg/L = ppm (parts per
million).
• Mass/mass or weight/weight: the mass of a solute in
a given mass of solution; typically mg/kg or ppm
(parts per million).
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