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CHAPTER ONE
EVALUATION OF SOLID WASTE MANAGEMENT
CHAPTER ONE
EVALUATION OF SOLID WASTE MANAGEMENT
Solid wastes include all solid or semisolid materials that the possessor no
longer considers of-sufficient value to retain.
Solid waste comprises all the waste arising from human and animal
activities that are normally solid and that are discarded as useless or unwanted.
Materials Flow and Waste Generation
An indication of how and where solid waste is generated in our
technological society is presented in Fig. 1.1.
Figure 1.1 Materials Flow and Waste Generation in a technological society
One of the best ways to reduce the amount of solid waste that must be
disposed of is to limit the consumption of raw materials and to increase the rate of
recovery and reuse of waste materials.
Unlike water-borne and air-dispersed wastes, solid wastes, solid waste will
not go away :
[ Where it is thrown is where it will be found in the future.]
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Solid Waste Management
Q1. Define solid waste management
: may be defined as the activities associated with the control of generation, storage,
collection, transfer and transport, processing, and disposal of solid wastes in a
manner that is in accord with the best principles of public health, economics,
engineering, conservation, aesthetics and other environmental considerations.
Functional Elements/ Definitions
Q2: State solid waste management functional elements and define each.
Six functional elements: (1) waste generation; (2) waste handling and separation,
storage, and processing at the source; (3) collection; (4) separation and processing
and transformation of solid wastes; (5) transfer and transport; and (6) disposal (Fig.
1.2)
Figure 1.2 Functional elements of Solid waste
Waste Generation
Encompasses activities in which materials are identified as no longer being
of value and are either thrown away or gathered together for disposal. For example
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the wrapping of candy bar is usually considered to be of little value to the owner
once the candy is consumed.
Waste Handling and Separation, Storage, and Processing at the Source.
Waste handling and separation involves the activities associated with
management of wastes until they are placed in storage containers for collection.
Handling also encompasses the movement of loaded containers to the point of
collection. On site storage is of primary importance because of public health
concerns and aesthetics consideration
Collection
The functional element of collection includes not only the gathering of solid
wastes and recyclable materials, but also the transport of these materials, after
collection, to the location where the collection vehicle is emptied. This location
may be a materials processing facility, a transfer station, or a landfill disposal site.
In small cities where the final disposal sites are nearby, the hauling of wastes is not
a serious problem. In large cities, however where the haul distance to the point of
disposal is often more than 15 miles (24.140 km) the haul may have significant
economic implications. Where long distances are involved, transfer and transport
facilities are normally used.
Separation, Processing, and Transformation of Solid Waste.
The fourth of the functional elements is recovery of separated materials that occurs
primarily in locations away from the source of waste generation.
Transfer and Transport.
The functional element of transfer and transport involves two steps: (1) the
transfer of wastes from the smaller collection vehicle to the larger transport
equipment and (2) the subsequent transport of the wastes, usually over long
distances, to a processing or disposal site.
Disposal
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The final functional element in the solid waste management system is
disposal. Today the disposal of wastes by land filling or land spreading is the
ultimate fate of all solid wastes. A modern sanitary land fill is not a dump it is an
engineered facility used for disposing of solid waste on land or within the earth s
mantle without creating nuisance or hazards to public health or safety, such as the
breeding of rats and insects and the contamination of ground water.
Q3. Define ISWM.
Integrated Solid Waste Management (ISWM) can be defined as a
comprehensive waste prevention, recycling, composting, and disposal program. An
effective ISWM system considers how to prevent, recycle, and manage solid waste
in ways that most effectively protect human health and the environment.
ISWM involves evaluating local needs and conditions, and then selecting
and combining the most appropriate waste management activities for those
conditions. The major ISWM activities are waste prevention, recycling and
composting, and combustion and disposal in properly designed, constructed, and
managed landfills. Each of these activities requires careful planning, financing,
collection, and transport.
Q4. Define the word hierarchy and what are its components as adopted
by the EPA, explain each
A Hierarchy ‫( التسلسل الهرمي‬arrangement in order of rank) in waste management
can be used to rank actions to implement programs within the community (Fig.
1.3). The ISWM hierarchy adopted by the U.S. Environmental Protection Agency
(EPA) is composed of the following elements: source reduction, recycling, waste
combustion, and landfilling.
Source Reduction (Waste prevention)
The highest rank of the ISWM hierarchy, source reduction, involves reducing the
amount and/or toxicity of the wastes that arc now generated. Source reduction is
first in the hierarchy because it is the most effective way to reduce the quantity of
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waste, the cost associated with its handling, and its environmental impact.
Waste prevention strategies include using less packaging, designing products to
last longer, and reusing products and materials. Waste prevention helps reduce
handling, treatment, and disposal costs and ultimately reduces the generation of
methane.
Recycling and Composting.
What is Recycling?
Recycling is the process that involves collecting, reprocessing, and/or
recovering certain waste materials (e.g., glass, metal, plastics, paper) to make new
materials or products. Some recycled organic materials are rich in nutrients and can
be used to improve soils. The conversion of waste materials into soil additives is
called composting. Recycling and composting generate many environmental and
economic benefits. For example, they create jobs and income, supply valuable raw
materials to industry, produce soil-enhancing compost, and reduce greenhouse gas
emissions and the number of landfills and combustion facilities.
Waste Transformation
The third rank in the ISWM hierarchy, waste transformation, involves the
physical, chemical, or biological alteration of wastes. The transformation of waste
materials usually results in the reduced use of landfill capacity and offering useful
byproducts. The reduction in waste volume through combustion is a well-known
example.
Landfilling
Ultimately, something must be done with the solid wastes that cannot be
recycled or reused and are of no further use. There are only two alternatives
available for the long-term handling of solid wastes and residual matter: disposal
on or in the earth's mantle, and disposal at the bottom of the ocean. Landfilling,
the fourth rank of the ISWM hierarchy and it is the lowest rank in the
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Figure 1.3 Hierarchy of Processing Technique of Solid Waste.
ISWM hierarchy because it represents the least desirable means of dealing
with society's wastes.
Q5. WHAT IS THE RELATIONSHIP BETWEEN CLIMATE
CHANGE AND SOLID WASTE?
WHAT IS THE GREENHOUSE EFFECT?
The Earth’s atmosphere contains many types of gases,including those known
as “greenhouse gases,” which hold in the sun’s warmth . Scientists call this
naturally occurring phenomenon the “greenhouse effect.” Greenhouse gases help
regulate global temperatures. Certain human activities such as burning fossil fuels
and dumping solid waste, however, produce additional greenhouse gases and upset
the natural balance by raising global temperatures.
WHY SHOULD I BE CONCERNED ABOUT GREENHOUSE GAS
EMISSIONS?
Greenhouse gas emissions are slowly changing the Earth’s climate. The
Earth has already become slightly warmer in the past 100 years and will continue
to become warmer. This could cause serious human health and environmental
consequences because a warmer climate may cause more frequent and severe heat
waves, damage agriculture, and cause droughts in some places and floods in others.
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HOW DOES SOLID WASTE IMPACT CLIMATE CHANGE?
Even before a material or product becomes solid waste, it goes through a
long cycle that involves removing and processing raw materials, manufacturing the
product, transporting the materials and products to markets, and using energy to
operate the product. Each of these activities has the potential to generate
greenhouse gas emissions through one or more of the following means:
■
Energy consumption. Extracting and processing raw materials,
manufacturing products, and transporting materials and products to markets all
generate greenhouse gas emissions by consuming energy from fossil fuels.
■ Methane emissions. When organic waste decomposes in landfills, it
generates methane, a greenhouse gas.
■Carbon storage. Trees absorb carbon dioxide, a greenhouse gas, from the
air and store it in wood through carbon sequestration. Waste prevention and
recycling of wood and paper products allow more trees to remain standing in the
forest, where they can continue to remove carbon dioxide from the air, which helps
minimize climate change impacts.
Different wastes and waste management activities have varying impacts on
energy consumption, methane emissions, and carbon storage. For example,
recycling reduces greenhouse gas emissions by preventing methane emissions from
landfills or open dumps and by preventing the consumption of energy for
extracting and processing raw materials. Communities that are looking for ways to
help prevent climate change can start by implementing an integrated solid waste
management program.
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Questions:
a. What are the greenhouse gases and what are the primary sources of these gases?
b. What are the environmental effects caused by global warming?
c. What are the environmental health effects that could be caused by global
warming?
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