Environmental Studies The Hong Kong Polytechnic University

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Environmental StudiesThe Hong Kong Polytechnic
University
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Recommended Reference Books

• 1.Introduction to Environmental Engineering and
  Science, 2nd edition
• Author Gilbert M. Masters
• Publisher Prentice Hall
• 2.Introduction to Environmental Engineering, 3rd
  edition
• Author Davis, Cornwell
• Publisher McGraw-Hill International
• 3. Environment Hong Kong

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Natural Resources And Environmental System
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Environmental System

• 1. Definitions
• Environment is the physical and biotic habitat
  which surrounds us that we can see, hear, touch,
  smell and taste.
• Pollution can be defined as an undesirable change
  in the physical chemical, or biological
  characteristics of the air, water or land that
  can harmfully affect the health, survival or
  activities of humans or other living organisms.
  

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• 2. Environmental systems
• Environmental systems can be classified into 3
  categories
• Water resource management system
• Air resource management system
• Solid management system

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• Water Resource Management System
• Water supply subsystem
• The nature of the water resource commonly
  determines the planning, design, and operation of
  the collection, purification, transmission, and
  distribution works.
• The 2 major sources used to supply community and
  industrial needs are referred to as
• Surface water
• i.e. stream, lakes and rivers

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• Groundwater
• i.e. water pumped from wells
• 3. Interaction of systems
• A number of different environmental problems are
  associated with water, air or land systems. Many
  of these problems will apply only within one of
  these systems, justifying the breakdown into
  these categories.

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Environmental System
Such a classification is also useful for easier
comprehension of related problems within one
system. Moreover, it is sensible because, for
managerial and administrative reasons, such
subfields as air pollution, water supply,
wastewater disposal and solid waste disposal are
often dealt with separately by governmental
agencies. Unfortunately, many important
environmental problems are not confined to an
air, water or land system but involve
interactions between systems.
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Environmental System
A current example is the acid rain problem
stemming from the emission of sulfur dioxide and
nitrogen oxide gases into the atmosphere from the
emission of sulfur dioxide and nitrogen oxide
gases into the atmosphere from the sacks of
generating stations, smelters, and automobile
exhausts. These gases are then transported by air
current over wide regions. Rainfall washes them
out, creating acid rain which is harmful to
aquatic life, forest and agricultural crops.

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Environmental System
While many environmental problems are local or
regional, others must be viewed from an overall
water-air-land interaction standpoint on a
national, continental, or global basis. A simple
illustration of this interaction is shown in
following figure and hips to explain how an
insecticide like DDT is now ubiquitous. 4.
Environmental problems Environmental problems are
always interrelated . Sometimes a solution to one
problem actually creates another problem.
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Environmental System
For example, when people are sick and dying from
disease, it is natural to want to improve human
health. The health is improved and infant
mortality is reduced, a pollution explosion may
results. To feed this growing pollution, natural
habitats are often converted into farmland. In
turn, the destruction of natural habitats
eliminates the native wild plants, predatory
animals, and parasites. But when natural
predators and parasites are killed, outbreaks of
insect pests become more common. When farmers use
pesticides to control the pests and protect the
crops, they also pollute the environments.

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Environmental System
The development of this entire cycle in itself
consumes irreplaceable fossil fuel supplies and
when fuel are burn, air pollutants are generated.

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Environmental System
To make the task a bit more manageable, we can
divide environmental descriptions into 5 main
types. (1) Overpopulation The human population
has risen very rapidly in recent years. This
increase has led people to ask whether the earth
has become overpopulated. Overpopulation may be
defined as the presence in a given area of more
people than can be supported adequately by the
resources available in that area.
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Environmental System
It is important first because overpopulation is
major case of all other environmental problems.
Fewer people would need less food, chop down
fewer trees, burn less oil, and discharge less
sewage into rivers. Second, remedies for
overpopulation and the starvation that
accompanies it are generally higher on our list
of priorities than other environmental concerns.
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Environmental System
(2) Pollution Pollution is a reduction in the
quality of the environment by the introduction of
impurities. There are 2 distinctly different
types of pollution. A. Concentration of natural
wastes Before modern civilization, most organic
wastes did not accumulate in the environment,
because they were dispersed sufficiently so that
decay organisms could consume and recycle them.
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Environmental System
Thus, the quality of the environment was not
impaired. In modern times, the organic wastes are
often produced in such a concentrated manner that
natural decomposition cannot clean the
environment rapidly enough. For example, a city
may house several million people in a small area
of land.
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Environmental System

• Organic wastes from such a city are not spread
  evenly about the countryside but instead are
  concentrated in a few locations sewage that is
  dumped into a river decays naturally but the
  process takes time. If the volume or the
  concentration of sewage is high, the water may
  not become purified by the time it reaches the
  next site downstream where pure drinking water is
  needed.

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Environmental System
Natural wastes can be inorganic as well as
organic. Inorganic wastes would include compounds
of elements such as lead, cadmium and arsenic.
These elements exist naturally in the soil and
rock all around us and are also present in small
concentration in our bodies. As a trace elements,
some are harmless, and many are even essential to
bodily functions. However, even moderate doses of
most inorganic compounds are poisonous.
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Environmental System
Such substances are often concentrated during
mining and smelting operations. B. Introduction
of synthetic chemicals into the environment
People have recently learned to make new
chemical compounds, called synthetic chemicals.
In 1985, 70,000 different synthetic chemicals
were produced in quantity for common use and
about 2000 new compounds have been entering the
environment every year since then.
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Environmental System

• They are present in paints, dyes, food additives,
  drugs, pesticides, fertilisers, fire retardants,
  building materials, clothes, cleaning supplies,
  cosmetics, plastics and so on.
• Some of the synthetic chemicals are drugs that
  save millions of lives every year and other are
  poisons. But because most of them are new to the
  environment, the traditional patterns of decay
  and recycling do not necessarily apply.

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Environmental System
A material that decomposes in the environment as
a result of biological action is said to be
biodegradable. Most natural organic wastes are
biodegradable many synthetic chemicals are not.
For example, plastics remain in the environment
for a long time because organisms that feed on
them and bread them down are rare. Plastic
shampoo bottles may produce unsightly litter, but
they are not biologically active.
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Environmental System
However, many other chemical compounds not only
are persistent but also are poisonous. Therefore,
represent a significant threat to the
environment. (3) Depletion of resources
Resources of fuels, minerals, water, soil, and
timber can be depleted or used up as it becomes
less available for its intended function.
Materials can become depleted in three different
ways.
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Environmental System
1) A substance can be destroyed, that is
converted into somethings else. Fuels are
destroyed when they are used. Coal is converted
to ashes and gas. Uranium is converted to
radioactive waste products. The ashes or waste
products are no longer fuels.
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Environmental System
2) A substance can be lost by being diluted, by
being displaced to some location from which it
cannot easily be recovered. If you open a
helium-filled balloon, the gas escapes to the
atmosphere. Not only atom of helium is destroyed,
but the gas is lost because it would be
impossible, as practical matter, to recover it.
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Environmental System
3) A substance can be rendered unfit for use by
being polluted. In this way, pollution and
depletion are related each other. If industrial
or agricultural wastes are discharged into a
stream or if they percolate down through soil and
porous rock to reach a supply of groundwater,
these water resources become less fit for
drinking or in the case of the stream, for
recreation or for the support of aquatic life.
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Environmental System
(4) Changes in the global condition a.Climate Over
the past 150 years or so a more instant in
geological time-humans have significantly altered
the chemistry of our environment. Today many
scientists believe that these changes might
affect the life support systems of the earth.
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Environmental System
For example, when fossil fuels are burned, carbon
dioxide is released. In turn, the excess
atmosphere carbon dioxide could possibly cause a
general warming of the entire earth.
Deforestation could affect global rates of
photosynthesis and the composition of the
atmosphere. Aerosol sprays and aircraft exhaust
may be destroying the ozone layer in the
atmosphere that filters out ultraviolet
radiation.
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b. Extinction of species Throughout mush of the
world, forests, shrublands and other natural
systems are being converted to farmland. When
habitats are destroyed, many organisms cannot
survive. Therefore, hundreds of thousands of
species of plants and animals are faced with
extinction. People often do not know precisely
what has been convinced that endangered species
of plants or animals should be saved to preserve
the genetic diversity of our planet.
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Environmental System
Some of these species are especially important,
because they may produce lifesaving drugs or may
be essential in breeding valuable crops or
domestic animals. (5) War In many wars, war is a
combination of all environmental problems rather
than a separated category. In modern times, war
ad the preparation for war have led to pollution
and depletion of resources far more extreme than
any single peacetime activity.
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People are killed, cities and farms are ruined
and forested regions are destroyed. But even in
the absence of actual conflict, the cost of
maintaining armaments and standing armies is
enormous. Finally, the potential for a nuclear
war places the global systems of the Earth, human
civilization and even the human species itself at
risk.
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In many jurisdictions, regulatory are now focused
on the generation of pollutants rather than on
the capture and disposal of pollutants. The
primary objective is to prevent or reduce
pollution at its source. If pollutants cannot be
prevented or reduced, they should be reused or
recycled in an environmentally acceptable manner.
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Environmental System
If pollutants cannot be prevented, reduced or
recycled, then they should be controlled or
treated to reduce their harmful effects on humans
and the environment. Disposal of untreated
pollutants should be used only as a last resort.
The idea is to analyze the production, use and
ultimate disposal of the product to avoid
creating pollution.
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• Wastewater disposal subsystem
• Safe disposal of all human wastes is necessary to
  protect the health of the individual, the family,
  and the community, and also to prevent the
  occurrence of certain nuisances. To accomplish
  satisfactory results, human wastes must be
  disposed of so that
• They will not contaminate any drinking water
  supply.
• They will not give rise to a public health hazard
  by being accessible to insects, rodents, or other
  possible carriers that may come into contact with
  food or drinking water.

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Environmental System

• They will not give rise to public health hazard
  by being accessible to children.
• They will not cause violation of laws or
  regulations governing water pollution or sewage
  disposal.
• They will not pollute or contaminate the waters
  of any bathing beach, shellfish breeding ground,
  or stream used for public or domestic
  water-supply purposes, or for recreational
  purposes.
• They will not give rise to a nuisance due to
  odour or unsightly appearance.

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Environmental System
Wastewater Management Subsystem. (SourceR.K.
Linsley and J.B. Fanzini, Water Resources
Engineering, New York McGraw-Hill, 1979.
Reprinted by permission.)
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Environmental System

• Air Resource Management System
• Our air resource differs from our water resource
  in 2 important aspects.
• The first is in regard to quantity. Whereas
  engineering structures are required to provide an
  adequate water supply. Air is delivered free of
  charge in whatever quantity we desire.
• The second aspect is in regard to quality.
  Unlike water, which can be treated before we use
  it, it is impractical to go about with a gas mask
  on to treat impure air and with ear plugs in to
  keep out the noise.

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Environmental System

• The balance of cost and benefit to obtain a
  desired quality of air is termed air resource
  management. Cost-benefit analyses can be
  problematic for at least 2 reasons.
• The question of what is desired air quality. The
  basic objective is, of course, to protect the
  health and welfare of people. But how much air
  pollution can we stand We know the tolerable
  varies from person and person.

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Environmental System

• The question of cost versus benefit. We know
  that we dont want to spend the entire Gross
  National Product to ensure that no individuals
  health or welfare is impaired, but we do know
  that we want to spend some amount. Although the
  cost of control can be reasonably determined by
  standard engineering and economic means, the cost
  of pollution is still far from being
  quantitatively assessed.

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Environmental System
Solid Waste Management Generally, solid waste is
considered a problem to be solved as cheaply as
possible rather than a resource to be recovered.
A simplified block diagram of a solid waste
management system is shown in following figure.
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Environmental System
A simplified block diagram of a solid waste
management system. (Source G. Tchobanoglous, H.
Theisen, and R. Eliassen, Solid Wastes, New York
McGraw-Hill, 1977. Reprinted by permission.)
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• Environmental Awareness
• Human activity affects the environment
• Sustainable development - urban, industrial
  environmental consideration awareness
• Environmental Protection depends on
• Attitude - Government, Citizen, Industrialist

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Environmental System
Role of government in environmental protection 1.
Environmental education in schools and
colleges. 2.Public awareness promotion informal
teaching by publicity in media drawing attention
to health hazards and propagranda or programs to
improve the environmental condition. 3.Release of
information on affairs and policies of
environmental concern, information on regulatory
control, standards and enforcement procedures.
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4.Education of the industrialists in providing
guidelines, training, regulation information,
self-esteemed motivation, and information on
complaint procedures. 5.Provide incentive for
pollution control practice for the
polluters 6.Administrative control good town and
landuse planning, pollution control zone,
frequent inspection on potential polluting
industries, and enforcement of the pollution
control legislation. 7.Legislation on pollution
prevention, laws and ordinance on environmental
protection. Government should show their own
compliance on the regulations for government
development projects as an example to
industries.
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Environmental System
Role of environmental education in the
enhancement of environmental protection 1.
Government attitude on environmental education
and its impact on secondary school students
influences on the present and future attitude on
environmental protection for the younger
generation. 2. Tertiary and technical institutes
environmental education programs and courses on
the training of the technical and professional
personnel for government and industrial sector on
environment management and pollution control.
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Environmental System
3. Environmental education on the public through
government, mass media, broadcasters, press and
their impact on the citizens and society. 4.
Educaiton of the industrial sector through
government persuasion, public awareness programs
and mass media exposure and promotion of
pollution control practice. 5. Education through
social awareness programs and the promotion of
environment friendly products.
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• Public participation
• 1. District board Industrial / Urban development
• 2. Environmental Protection COMmittee (EPCOM)
• nominate prominent citizens, environmental group,
  industry, government departmental representative
  EPD
• Advisory committee on environment-related policy
  matter
• 3. Environmental groups

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Environmental System

• Public Participation are important as different
  interests in the development are balanced through
• Familiarization of the project by the public
• Problems identified EIA (Environmental Impact
  Assessment)
• Interest identified
• Public review of the project
• Conflicts resolved sustainable development

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Environmental System
Public participation will ensure that all
interests are balanced and the parties concerned
will include environmental consideration in the
planning, design, constructional and operational
stages and that steps are taken to minimize the
adverse impacts on the environment to the
satisfaction of society.
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Environmental System

• Industrialists Attitude
• Environmental education of industrialists (Volunt
  ary)
• Environmental control practice high percentage
  unproductive
• Government Legislative / Administrative
  Control (Compulsory)
• Citizen response environmental friendly products
• Competitive products and funding available

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Environmental System

• Social background on the individuals opinion
  and reaction to environmental pollution
• Level of education -- more highly educated person
  tend to be more fussy about environmental
  matters
• Affluence -- environmental awareness seems to
  increase with affluence -- expects better
  standard of living

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Environmental System

• Parents view family members views on
  pollution
• Friends view circle of contact
• What pollution problems existed in the area in
  which they were brought up.
• Publicity media promotion of environmental
  concept.