This document provides an overview of a course on urban waste management. It will cover major topics like types of wastes, waste processing and control, and waste management policies and strategies. The course will be taught through lectures, exercises, assignments, and assessments including quizzes, midterms, projects, and a final exam. It aims to help students understand environmental problems in urban areas, components of solid and liquid waste, waste disposal options, benefits of recycling and reusing waste, and approaches to air and water pollution control.

1. HAWASSA UNIVERSITY
INSTITUTE OF TECHNOLOGY
SCHOOL OF BSWRE
DEPARTMENT OF WSEE
URBAN WASTE MANAGEMENT
WSEE4054
BY DEREJE G. (MSC.)
4/27/2023
By
Dereje
G.
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2. DETAIL DESCRIPTION
 you will be able to :-
 learn how to identify some important environmental problems existing
in urban centers,
 learn major components of solid and liquid waste,
 explain the different waste water disposal options as well as the
advantages and disadvantages they offer,
 develop basic understanding on the benefits, problems and potential of
recycling, reusing and recovery of wastes,
 describe the major categories, sources and effects of air pollution on
climate, human health, vegetation and building material,
 describe the sources and effects of major types of water pollution and
 compare different approaches to air and water pollution control
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3. MODALITY
 Status of course:- core (compulsory)
 Mode of Delivery :- Lecturer, exercise , Assignment
 Mode of Assessment:-
Quiz ………………………..………..……….10
Mid exam ……………………………………15
Project ……………………………………….15
Assignment………………………………….15
Final exam …………………………….……50
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4. CONTENT
 Introduction
 Types Of Wastes
 Waste Processing And Control
 Waste Management Policies And Strategies
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5. CONT.…
 The Chapter discusses the generation, treatment, disposal and
management of the growing volume of waste, which poses
formidable challenges to both high and low-income countries of
the region.
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6. INTRODUCTION
 Waste is an unavoidable by-product of most human activity.
 Economic development and rising living standards have led to
increases in the quantity and complexity of generated waste
(General),
 Whilst industrial diversification and the provision of expanded
health-care facilities have added substantial quantities of industrial
hazardous waste and biomedical waste into the waste stream with
potentially severe environmental and human health consequences.
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7. TYPES OF WASTES
 Waste can be classified based on:-
1. Generation and Characteristics
2. Environmental Impacts of Waste
1. Generation and Characteristics
 quantities and characteristics of the waste being generated is a key
component in the development of strong and cost-effective waste
management strategies.
 But little priority is given to the systematic surveying of waste
arising and the quantities, characteristics, seasonal variations and
future trends of waste generation which are poorly understood.
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8. CONT.…
 It is known that developed countries generate much higher
quantities of waste per capita compared to the developing countries
of the region.
 However, in certain circumstances the management of even small
quantities of waste is a significant challenge.
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9. 2 ENVIRONMENTAL IMPACTS OF WASTE
 The economic growth and urbanization experienced in many parts of
the World has significantly escalated the quantities of MW being
generated in many cities
 Uncontrolled, open dumping on the peripheries of many of the
region’s cities has resulting in the degradation of valuable land
resources and the creation of long-term environmental and human
health problems.
 Throughout the region, indiscriminate dumping has led to the
contamination of surface and ground water supplies,
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10. CONT….
 whilst open burning of waste contributes significantly to urban air
pollution.
 At a global level, the uncontrolled release of methane, which is
produced as a by-product of the decomposition of organic wastes,
represents a significant proportion of the region’s contribution to the
greenhouse effect and fire.
 The increase in potentially hazardous industrial, biomedical and
nuclear wastes has not been accompanied by a commensurate
expansion in the provision of waste treatment and management
facilities.
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11. CONT.….
 The uncontrolled dumping of biomedical waste has the potential for
transporting pathogens (disease producing organisms),
 whilst the indiscriminate disposal of oils, used batteries, discarded paints,
spent chemicals and carcinogens, such as asbestos, can cause significant
adverse impacts on human health and the environment.
 Various incidents of pollution have also been reported from industrial
waste, abattoirs or food processing plants along with biocides and toxic
effluents from sawmills and timber processing areas.
 Based on the above two points waste can be classified as solid and liquid
wastes
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12. 4/27/2023
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13.  COURSE CONTENT
An Overview of Solid Waste Management
 Solid Waste Generation, Trends and Statistics
 Biological Treatment and Composting of sw
 Stabilization/Solidification of SWs
 Waste Recycling and Producer Responsibility
 Waste Minimization
 Life Cycle Analysis of Waste Mgt Options
 Landfill Design and Construction
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14.  COURSE OBJECTIVES:
 On completion of the course, you will be able to:
 Understand the implications of production, resource mgt and
environmental impact of SWM
 Design SWM infrastructure systems to minimize its impacts
 The significance of recycling, Reuse & Reclamation of SWs
 Understand the relationship b/n poor waste mgt practices and
impacts on water, soil and sediment quality
 Appreciate the current practices available and implement
available systems in SWM
 Assess the relationships b/n environmental guidelines,
human activities and environmental quality of polluted soils
and water
 Integrate technical options and environmental legislation and
guidance of SWM for the development of legal and safe
solutions
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15.  Solid Waste Generation, Trends & Statistics
 What is Solid Waste?
 Human activities generate waste materials that are discarded
because they are considered useless
 The physical state of these materials is solid
 The word waste  any unwanted item or substance resulting
from a human activity or production processes that is useless
 Solid Waste comprise all the wastes from human and animal
activities that are solid and semi-solid and are discarded as useless
or unwanted
 It does not mean that the SW being discarded have no value
 It simply means that the SW have no value for the current owner
but it can be reused and become a resource for another owner if
managed properly
 Municipal Solid Waste (MSW) includes all the wastes generated in
a community, except waste generated by municipal services,
treatment plants and industrial and agricultural processes
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16.  Solid Waste is a consequence of life
 Humans and animals have used the resources of the Earth to
support life and to dispose of waste
 Waste is a consequence of everyday life of all creatures
 Humans have been producing solid waste forever as part of life
 In early times, the disposal of wastes did not pose a significant
problem
o Population was small
o Assimilation capacity of the environment was large
 Hunters & gathers
 Ultimate composters
 No packaging
 All biodegradable
 wastes had no impacts (health & Env’t)
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17.  Wastes disposal become the problem when humans first began to
congregate in:
o Tribes
o Villages
o Communities
 Open Dumps
 1st created in 500 B.C. in Athens, Greece
 Outlawed in U.S. & many other DC
 Some illegal dumping still occurs
 Still used by many developing countries
 Many poor families work on dumps to get food or recyclables
 Cons:
 Attracts vermin & insects
 Smells
 Methane causes spontaneous fires (Smokey Mtn in Phillipines)
 Aesthetic degradation
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18.  Sources & Composition of Solid Wastes
 Primary source
 Production of commodities
 By products from Solid Materials
 Everything produced is eventually discarded as waste
 Secondary source (natural cycle of plant growth & decay)
 Yard waste/vegetative waste
 Municipal solid waste = 1.5%
 Mining, Oil and gas production, Agriculture, treatment facilities &
Industry = 98.5%
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19.  Sources of Solid Wastes….
 SW may arise from the ff sources :
 Residential: all SWs produced by people living in residences
such as single-family homes, duplexes, town houses, low,
medium and high rise apartments
 Commercial: all SWs produced by commercial
establishments including office buildings, print shops,
shopping malls, warehouses, hotels, airports, restaurants,
auto repair shops
 Institutional: all SWs produced by schools, medical
facilities, prisons, government centres
 Agricultural: all solid wastes produced from farming
operations such as field and row crops, orchards,
vineyards, dairies, feedlots, farms
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20.  Sources of Solid Wastes….
 Mining: all residues remaining from mining and mineral
processing operations
 Industrial: all non-hazardous solid wastes produced by
industrial manufacturing plants such as packaging of
components, office wastes, lunchroom and restroom
wastes but not industrial process wastes
 Municipal Services: all solid wastes from street cleaning,
landscaping, catch-basin cleaning, parks and beaches,
other recreational areas
 Treatment plant Wastes: all sludge solid wastes produced by
water, wastewater and industrial treatment processes
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21.  Sources of Solid Wastes….
 Construction and demolition: all solid wastes generated
during the normal construction of houses, apartments, commercial
establishments and industrial factories or from the destruction of
houses, apartments
 New construction sites, road repair renovation sites, razing of
buildings, broken pavement
 Examples: bricks, concrete and other masonry
materials, soil, wood, wall coverings, plaster, drywall,
plumbing fixtures, non-asbestos insulation, roofing
shingles, asphaltic pavement, glass, plastics, metals
…
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22.  Summary of Sources & composition of SW
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23.  Percentage distribution of components vary from country to
country, community to community depending several factors
 Types & Sources of SW in USA
 Types & Sources of SW in EU
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24.  CHARACTERISTICS OF SOLID WASTE S/ benefit /
 Understanding of the characteristics of waste stream is important
for all SWM methods
 Good planning goes beyond developing a snapshot of current
waste composition
 The long-term trends in waste stream characteristics are important
 If future quantities and components of the waste stream are under-
or overestimated, then facilities may be over- or undersized
 In developing SWM programs, it is important to identify the
sources, characteristics and quantities of SW
 Information on SW characteristics is important in determining the
 Types of collection services
 Types of collection vehicles
 Types of processing facilities
 Disposal methods
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25.  CHARACTERISTICS OF SOLID WASTES….
 The purpose of characterization is to promote sound mgt
o size, capacity and design of facilities to manage the waste
o potential for recycling or composting portions of the waste stream
o effectiveness of waste reduction programs, recycling programs or
bans on the disposal of certain materials
o Potential sources of environmental pollution in the waste
 The immediate purpose of waste characterization is to comply with
regulatory mandates and to obtain data for preparing bids to design,
construct and operate SWM facilities
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26. CHARACTERISTICS OF SOLID WASTES….
 If all waste is to be landfilled, the characterization program
focuses on:-
o Quantity of waste , Its density and Its potential for compaction
 Composition and chemical characteristics will not be important
 If all waste is to be incinerated, the critical parameters are
o Quantity, Heat value and Percentage of combustible material
 If recycling and composting are planned or underway, a
composition study can identify
o Materials targeted for recovery
o Estimate the abundance of recoverable materials in the waste
o Monitor compliance with source separation
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27.  BASIC CHARACTERIZATION METHODS
 EEs use one of 2 fundamental methods to characterize SW
 Material flows methodology: collect and analyze data on the manufacture
and sale of products that become SW after use
 Direct field study of waste (sampling): determination of the
composition of SW in the field
 Generalized field procedures based on
o Common sense
o Random sampling techniques
 To date, only the material flows method has been used to characterize
the MSW stream nationwide
 Data sources for material flows methodology include:
o Domestic production of the materials
o Products in municipal solid waste
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28.  Data series consistent from year to year rather than a single point in time
allows the methodology to obtain meaningful historical data that can be used
for establishing time trends
 Numerous adjustments are made to the raw data:
 Deduce scrap (industrial process waste not MSW)
 Make adjustments if imports and/or exports are a significant portion of
the products being characterized
 Make adjustments for various diversions of products from disposal as
MSW (e.g., toilet tissue which goes into sewer systems rather than solid
waste)
 Make adjustments for product lifetimes (e.g., all containers and
packaging and most non-durables are disposed of the same year they are
produced but durable products such as appliances and tires are designated
as “lagged”)
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29. METHODS OF CHARACTERIZING SW
Material Flows
 Nationwide Characterization
 Characterizes generation & discards
 Provide long-term trends data
 On an annual basis
 Doesn’t account for regional differences
 Characterizes as SW generated
moisture basis
 The entire waste stream is measured
instead of samples
 Results tend to be more consistent than
the results of sampling
 Updates are inexpensive once
analytical structure is established
 Suitable to track economic trends that
influence the SW stream
 Cannot measure the generation of
food wastes, yard trimmings and
some miscellaneous inorganic wastes
 Obtaining complete production data for
every item discarded as SW is difficult
Sampling
 Characterizes at sampling facility
 Characterizes only discards
 Provide one point in time data
 Site-specific
 Provide data on regional
differences
 Characterizes after they have
been mixed and moisture
transferred
 data on seasonal fluctuations
 The more detailed a waste
characterization study
 Statistically meaningful field
studies are expensive
 Measure generation of food
wastes, yard trimmings and some
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30.  Material Composition of Solid Wastes
 Distribution for components in SW vary with:
 Location
 Season (time of the year)
 Habits, education and economic status of the people
 Number and type of commercial and industrial operations
 Whether the area is urban or rural
 For design purposes each community should be studied and
actual weighings made to obtain representative data
 Due to its heterogeneous nature, determination of the
composition of SW is not easy
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31.  Materials in Municipal Solid Waste
1. Paper and Paperboard
 The largest component of the MSW stream (> 1/3 of total
generation)
 Found in a wide variety of products in 2 categories of MSW:
o Non-durable goods (newspapers, books, office papers, Tissue paper
and towels, directories, magazines, catalogs, commercial printing
including advertising inserts in newspapers, reports, brochures, telephone
books, disposable plates and cups and the like)
o Containers and packaging (corrugated boxes, folding cartons (e.g.,
cereal boxes), milk cartons, paper bags and sacks and other kinds of
packaging)
 Good recycling potential
Table: Paper and Paperboard Products in
Municipal Solid Waste
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32. 2. Glass
 Glass containers used for beer and soft drinks, wine and liquor,
food products, toiletries and in some durable goods
 Generation trend has dropped owning to 1st Al cans and then
plastic bottles encroached on the markets
 Almost all can be recycled
Table: Glass Products in Municipal Solid Waste
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33. 3. Metals (Ferrous, Nonferrous Metals & Al)
 Ferrous Metals
 Steel and iron in major durable goods such as appliances, furniture, tires
& miscellaneous items
 Steel cans mainly package food, with small amounts in beverage cans
and other packaging
 The generation pattern of steel in containers and packaging is much like
that of glass (it has been displaced by plastics )
 Good recycling potential
 Al
 Al containers and packaging and in some durable and non-durable goods
 E.g., Beer and soft drink cans, food and other cans, foil and closures
 Nonferrous Metals
 Non-ferrous metals (e.g., lead, copper, zinc)
found in durable goods (e.g. lead in automotive batteries)
Table: Metal Products in Municipal Solid Waste
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potential

34. 4. Plastics
 used very widely in the products found in MSW
 found in plates and cups, Trash bags, Disposable diapers, clothing and
footwear, Soft drink bottles, milk and water bottles, bags and sacks, wraps …
 Found in durable goods (appliances, carpeting and furniture)
 containers are the largest source of plastics in MSW (soft drinks, milk, water,
food and other products) and packaging (bags, sacks, wraps, closures and
other miscellaneous packaging products)
 Plastics are strong, waterproof, lightweight, durable, microwavable and more
resilient than glass
 They have replaced wood, paper and metallic materials in packaging
and other applications
 Recycling programs developed
 IR Code (1 - 7) marked on most
plastics
 1: PETE;
 2: HDPE;
 3: PVC;
 4: LDPE;
 5: PP;
 6: PS;
 7: All other plastics
Table: Plastic Products in SW
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35. PLASTIC RECYCLING CODES
 Polyethylene terephthalate, PETE-1
 High-density polyethylene, HDPE-2
 Polyvinyl chloride, PVC-3
 Low-density polyethylene, LDPE-4
 Polypropelyne, PP-5
 Polystyrene, PS-6
 All Other, 7
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36.  Common Types of Plastics That May Be Recycled
Code Abbreviati
on
Chemical name Typical uses
1 PETE Polyethylene terephthalate Soft drink bottles
2 HDPE High-density polyethylene Milk bottles
3 PVC Polyvinyl chloride Food packaging, wire
insulation, and pipe
4 LDPE Low-density polyethylene Plastic film used for food
wrapping trash bags, grocery
bags and baby diapers
5 PP Polypropylene Automobile battery casings and
bottle caps
6 PS Polystyrene Food packaging, foam cups and
plates and eating utensils
7 PLA Mixed plastic Fence posts, benches, pallets,
and compostable packaging
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37. 5. Other Materials in Products
 Materials that cannot be classified into basic material categories
according to material flows methodology
o Rubber and Leather (found in tires, furniture and furnishings and carpets,
clothing and footwear)
o Textiles (found in clothing and household items such as sheets and
towels & in items like tires, furniture and footwear)
o Wood (found in durable goods such as furniture and cabinets for
electronic goods and in the containers and packaging category in
shipping pallets and boxes)
o Other Materials (disposable diapers including the fluff (wood) pulp used in the
diapers as well as the feces and urine that are disposed along with the diapers &
electrolyte in automotive batteries)
 Food Wastes
 uneaten food and food preparation wastes from residences,
commercial establishments (e.g., restaurants), institutions
(e.g., schools and hospitals), and some industrial sources
(e.g., factory cafeterias or lunchrooms)
 The only source of data on food wastes is sampling studies
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38. 6. Yard Trimmings
 Grass, leaves and tree and brush trimmings from residential, commercial
and institutional sources
 Estimated based on sampling study data
 Varies seasonally & geographically
7. Miscellaneous Inorganic Wastes
 Includes soil, bits of stone and concrete and the like
 Estimates are derived from sampling studies
 The items in the category would usually be classified as fines
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39.  Composition of MSW, % by weight in d/t countries
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40.  Composition of MSW in Australia (left) and USA
(right)
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41.  Distribution of components of MSW
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42.  Products in MSW by Weight
 Used and discarded products contain materials found in MSW
 These products can be classified as:
1. Durable goods (products having lifetimes of 3 yrs or
more; include major appliances (refrigerators, washing
machines, stoves), small appliances, furniture and
furnishings, carpets and rugs, rubber tires, lead-acid
automotive batteries and miscellaneous durables like
electronics goods such as televisions and personal
computers & a variety of other products such as
luggage and sporting goods)
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43. 2. Nondurable goods
 Discarded the same year they are manufactured
 Have lifetimes of < 3 yrs
3. Containers and Packaging:
 includes both primary packaging (the containers that directly hold food,
beverages, toiletries and a host of other products) and secondary and
tertiary packaging, which contain the packaged products for shipping and
display)
 all containers and packaging are discarded the same year they are
manufactured (except a few such as reusable wood pallets)
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44. 4. Other Wastes
 Food wastes, yard trimmings and miscellaneous
inorganic wastes
 Added to the product categories of durable goods,
nondurable goods and containers and packaging to
obtain total generation of SW
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45.  PHYSICAL, CHEMICAL & BIOLOGICAL PROPERTIES OF SW
 PHYSICAL PROPERTIES OF SW include
 Specific Weight (Density)
 Moisture Content
 Particle Size and Distribution
 Field Capacity
 Permeability of Compacted Waste
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46.  Specific Weight (Density)
 The weight of a material per unit volume (kg/m3)
 Refers to uncompacted waste
 Varies with geographic location, season of the year and
length of time in storage
 The variabilities are due to variations in moisture content
 Typical Specific Weight Values (Table)
It affects:
The number and size or
type of SW containers,
collection vehicles and
transfer stations
 Transportation systems
and land requirements for
disposal
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47.  Typical Specific Weight Values (Fig.)
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48.  Moisture Content of SW
 The moisture in a sample is expressed as percentage of the wet
weight of the SW material
 Analysis Procedure:
 Weigh the aluminum dish
 Fill the dish with SW sample and re-weigh
 Dry SW + dish in an oven for at least 24 hrs at 105°C
 Remove the dish from the oven, allow to cool in a desiccator and weigh
 Record the weight of the dry SW + dish
 Calculate the moisture content (M) of the SW sample using the equation
given above
 It may vary between 15 & 30% and is usually about 20%
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49.  Typical Moisture Contents of Wastes (Table)
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50.  Particle Size and Distribution
 The size and distribution of the components of wastes
are important for the recovery of materials, especially
when mechanical means are used, such as trommel
screens and magnetic separators
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51.  Field Capacity (FC)
 The total amount of moisture that can be retained in a waste
sample subject to the downward pull of gravity
 It varies with the degree of applied pressure and the state of
decomposition of wastes
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52.  Field capacity ….
 Field capacity is critically important in determining the formation of
leachate in landfills
 The potential quantity of leachate is the amount of moisture within the
landfill in excess of the landfill field capacity
where FC = field capacity (i.e., the fraction of water in the waste based on the dry
weight of the waste)
W = overburden mass calculated at the midheight of the waste in the lift in
question, lb
 The quantity of leachate is a direct function of the amount of external
water entering the landfill
 If a landfill is constructed properly leachate production can be reduced
 When WWTP sludge is added to the SWs to increase the amount of
methane produced leachate control facilities must be provided
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53.  Permeability of Compacted Waste
 The permeability (hydraulic conductivity) of compacted
SW is an important physical property because it governs
the movement of liquids & gases in a landfill
 Permeability depends on
o Particle size distribution
o Surface area
o Porosity
Typical Compaction Factors for
Various Solid Waste
Components Placed in Landfills
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54.  CHEMICAL PROPERTIES OF MSW
 Chemical properties are very important in
evaluating the alternative processing and
recovery options:
o Proximate analysis
o Fusing point of ash
o Ultimate analysis (major elemental analysis )
o Energy content analysis
 Proximate Analysis
Quick and inexpensive lab. determination of the
percentages of moisture, volatile matter, fixed
carbon and ash
An important method to determine whether the
given waste is suitable for incineration and how
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55.  Typical Proximate Analysis Values (% by weight)
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56.  CHEMICAL PROPERTIES OF MSW
The combustible components of SW includes
the ff tests:
Moisture (drying at 105 oC for 1 hr)
Volatile combustible matter (ignition at 950 oC
in the absence of oxygen)
Fixed C (combustible residue left after Step 2
above)
Ash (weight of residue after combustion in an
open crucible)
 The sum of moisture, volatile matter, Fixed
carbon & ash should equal to 100%
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57.  Fusing Point of Ash
 The temperature at which the ash resulting from the
burning of waste will form a solid (clinker) by fusion and
agglomeration
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58.  Ultimate Analysis
 The determination of percent C (carbon), H
(hydrogen), O (oxygen), N (nitrogen), S (sulfur),
halogens and ash
 Used to characterize the chemical composition of the
organic matter in SW
 Also used to define the proper mix of waste materials
to achieve suitable C:N ratios for biological conversion
processes
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59.  Typical data on ultimate analysis of combustible
materials found in SW
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60.  Typical data in elemental analysis (% by weight)
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61.  Energy Content of Solid Waste
 Energy content of SW can be determined by
o Using a full scale boiler as a calorimeter
o Using a laboratory bomb calorimeter
o Calculation based on
 Most of the data on the energy content of the organic
components of MSW are based on the results of
bomb calorimeter tests (Fig.)
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62.  Inert residue and energy content of residential
MSW
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63.  Average composition and heating values for MSW
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64.  Energy content of SW components
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65.  Essential nutrients & other elements
 Important if organic fraction of MSW is to be used for production
of compost or CH4
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66.  Biological Properties of MSW
 The OFMSW (excluding plastics, rubber and leather) can be
classified as:
 Water-soluble constituents: sugars, starches, amino
acids and various organic acids found in food wastes
 Hemicellulose: green (food, yard etc.) wastes
 Cellulose: waste paper, green (food, yard etc.) wastes
 Fats, oils and waxes: food wastes
 Lignin: waste paper, yard waste (brown-woody)
 Lignocellulose: combination of lignin and cellulose
 Proteins: food wastes
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67.  Biodegradability of MSW
 Almost all of the organic components in MSW can be
converted biologically to gases (CH4 & CO2), inert organic
and inorganic solids
 Volatile solids (VS), determined by ignition at 550 oC, is
often used as a measure of the biodegradability
 Components such as Newsprint are highly volatile but
low in biodegradability due to their high lignin content
 Practically, organic waste components in MSW are often
classified as rapidly and slowly decomposable
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68.  Biodegradable fraction of selected organic waste
components
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69.  Calculation of biodegredable fraction of MSW
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70.  Production of odors
 When SWs are stored for long periods of time on-site b/n collections,
in transfer stations and in landfills
 It is more significant in warm climates
 Due to anaerobic decomposition of decomposable organic components
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70

71.  Solid Waste Management (SWM)
 The control, generation, storage, collection, transfer and transport,
processing and disposal of SW
 Has to be done in accordance with the best principles of public health
(decrease in diseases), economics, engineering, conservation,
aesthetics and that has to be also responsive to public attitudes
(involvement of community)
 All administrative, financial, legal, planning, Architectural,
environmental and engineering functions involved in solution of all
problems of SW
 Before starting to plan mgt activities, it is important to know as much
about SW as possible
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72.  Proper SWM is an ongoing concerning about:-
 Promotion of MOs that cause diseases
 Generation of noxious odors
 Environment pollution (water, soil, air, sediment)
 Occupy valuable land that could be used for other purposes
 Degrade aesthetic quality of the environment
 Attraction and support of disease vectors (carriers of pathogenic
MOs)
 A fire hazard
 Resource wastage that could be raw materials to produce goods,
feed stock for composting and mulching processes and fuel
 Environmental and Ecological Damage
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73.  Indiscriminate dumping of SW & failure of the collection
system cause:
 Odors
 Flies
 Rats
 Roaches
 Crickets
 Wandering dogs and cats
 Fires
 Objectives of SWM
o Public hygiene and health
o Reuse, Recycle and Recovery (3R’s)
o Energy Generation (waste to Energy)
o Sustainable Development (SD)
o Aesthetics
o Environmental Pollution (air, water, soil, sediment)
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74.  Functional Elements of a SWM System:
 Sources of SW
 Characteristics and quantities of SW
 On-site storage and handling of SW
 Collection of SW
 Transfer and Transport of SW
 Reduction, Recycling and Processing of SW
 Composting of SW
 Sanitary landfill Planning, Design and operation
 Incineration of SW
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75.  Solid Waste Generation on a Per Capita Basis
 Solid waste generation refers to the amount of materials and products in SW as they enter the
waste stream before any materials recovery, composting or combustion take place
 MSW generation on a per person per day basis is often important for planning purposes
 It determines the size and number of the facilities and equipment required to manage the
waste
 Also the fee collected for each unit quantity of waste delivered to the facility is based on the
projected cost of operating a facility divided by the quantity of waste the facility receives
 Solid waste generation rate refers to the quantity of solid waste generated and collected per
person per day
 Factors affecting generation rates
 Seasonal changes
 Weekly and Daily Variations
 Source type
 Family size
 Collection practice
 Infrastructure
 Population density
 Economy
 Statistical properties
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76.  Some factors tending to increase MSW generation
 Some factors tend to decrease MSW generation
o Redesign of products: some products have grown lighter
(Refrigerators, rubber tires, packaging, newspapers)
o Materials substitution: substitute lighter materials in many applications
(Al cans ►replaced steel cans; plastic bottles ►substituted for glass)
Factor How affect generation
Population
growth
More people use and throw away more things
Increasing levels of
affluence/wealth/
Generation of MSW and economic activity have strong
correlation
Changes in
lifestyles
Individuals living alone, families with two wage earners
and single-parent families tend to buy more
prepackaged food and to eat out more
Changes in work
pattern
Increase in the number of office workers demand more
personal computers, high-speed copiers and facsimile
machines
New products New products such as disposable diapers may increase
the amounts of MSW generated
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76

77.  SW HANDLING AND SEPARATION, STORAGE AND
PROCESSING AT THE SOURCE
 SW handling refers to activities associated with managing SW
until they are placed in the containers used for storage before
collection
 Separation of waste components such as waste paper,
cardboard, aluminum cans, glass and plastic containers at the
source to achieve recovery and reuse (recycled)
 Storage within home and periodically transfer to larger
containers
 Placing directly in containers
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78.  Auxilary Equipment and Facilities used for handling SW @ Source
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79.  Gravity feed refuse chutes
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80.  Separation & Storage of SWs at Source
 Factors that must be considered in on-site storage
o Effects of storage on the waste components
o Type of container to be used
o Container location
o Public health and aesthetics
 Effects of storage on waste components
o Biological decomposition (putrefaction)
o Absorption of fluids
o Contamination of waste components
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81.  SOLID WASTE COLLECTION
 Gathering of SWs and recyclables and transport of collected
materials to location where collection vehicle is emptied (MRF, a
transfer station or a landfill)
 Of the total amount of money spent on SWM (collection, transport,
processing, recycling and disposal), about 50 – 70% is spent on the
collection activity
 Many new devices and methods have been proposed to cut costs ( e.g.,
careful design of collection systems)
 Solid waste Collection operation includes:
o The gathering or picking up from various sources
o Hauling to the location where the contents of the collection vehicles are
emptied
o The unloading of collection vehicles
 Hauling and unloading are similar for most collections
 The gathering or picking up will vary with the
o Characteristics of the facilities
o Locations where wastes are generated
o The ways and means used for on-site storage
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82.  SOLID WASTE COLLECTION…
 Collection Frequency No of collection/unit time
 It depends on the
o Quantity of SW
o Time of year
o Socioeconomic status of the area
o Contractor responsibility
 The maximum permissible interval in residential areas:
o Twice-a-week during warm months of the year
o Once a week at other times of the year
 In business districts SW should be collected daily except
Sundays
 Bulky wastes should be collected every three months
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83.  Collection System Types
 SW collection systems may be classified from several points of view
:
o Mode of operation
o Equipment used
o Types of waste collected
 Collection systems have been classified into two
categories according to their mode of operation:
o Hauled container systems (HCS)
o Stationary container systems (SCS)
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84.  Transfer & Transport
 The rising labor, operational and fuel costs and the absence of
nearby solid waste disposal sites transfer stations are becoming
common
 Facilities used to effect the transfer of wastes from
one location to another, usually more distant, location
 Contents of small collection vehicles are transferred to larger
vehicles that are used to transport the waste over extended
distances either to MRFs or to disposal sites
 Transfer and transport operations are also used in conjunction with
MRFs to transport recovered materials to markets or waste-to-
energy facilities and to transport materials to landfills
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85.  Transfer & Transport….
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86.  INTEGRATED SW MGT (IWM)
 Up to the 197Os, the perception of waste as unwanted, ‘useless’
material with no intrinsic value shaped society’s approach to
WM
 The overriding priority was ultimate disposal
 Generators sought disposal at the lowest cost and had little or
no incentive to ‘manage’ solid wastes
 The past few decades have witnessed a sea change in attitudes
to waste
 Waste generators and policy makers turned their attention to
waste minimization and more efficient use of ultimate
disposal capacity
 Siting of new facilities has at best proceeded
o After lengthy delays
o In the teeth of intense opposition
o At worst become impossible
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87.  ISW is the selection and application of suitable techniques,
technologies and management programs to achieve specific WM
objectives and goals
 Options for WM are often arranged in a hierarchical manner to
reflect desirability
o Waste avoidance
o Waste minimization waste prevention
o Recovery, reuse and recycling (3R’s)
 Disposal (after extracting resources in the form of products
and/or energy)
 According to U.S.EPA IWM has four basic mgt options
(strategies) :
 Source Reduction
 Recycling and composting
 Combustion (waste-to-energy facilities)
 Landfills (Disposal)
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88.  Hierarchy of integrated solid waste management (Fig.)
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89.  Landfill Design, Construction and Operation
 A controlled method of SW disposal
 Not an open dump
 Landfill is an engineered physical facility used for the disposal
of SW and SW residuals in the surface soils of Earth
 Solid waste residues are waste components that are not recycled,
remain after processing at a MRF or remain after the recovery of
conversion products and/or energy
 Sanitary landfill refers to an engineered facility for the
disposal of MSW designed and operated to minimize public
health and environmental impacts
 Monofills are landfills for designated wastes (e.g., combustion ash,
asbestos and other similar wastes)
 Secure landfills are landfills for the disposal of hazardous wastes
 Disposal of solid wastes is placement of the waste so that it no
longer impacts human health or the environment
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90.  Landfilling is the process by which SW and SW residuals are
placed in a LF and includes:
 Monitoring incoming waste stream
 Placement and compaction of the waste
 Installation of monitoring and control facilities
 Landfill management incorporates the
 Planning landfill
 Design landfill
 Operating landfill
 Environmental Monitoring
 Closure and post-closure Care
 The use of LFs is most economical and environmentally
acceptable method of SWs disposal
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91.  Definition of Landfilling Terms
 Cell (deposited solid waste and the daily cover material, 3-5m
high) is the volume of material placed in a landfill during one
operating period (usually 1 day)
 Landfill liners are materials (both natural and man-made) that
are used to line the bottom area and below-grade sides of a
landfill
 Daily cover (also called intermediate cover) is the native
soil or alternative materials such as compost, foundry sand
or auto shredder fluff that are applied to the working faces
of the landfill at the end of each operating period
 The final cover is applied over the entire landfill surface after
all landfilling operations are completed
 Consist of successive layers of compacted clay and/or
geosynthetic material designed to prevent the
migration of landfill gas and limit the entry of surface
water into the landfill
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92.  Definition of Landfilling Terms…
 A lift is a complete layer of cells over the active area of
the landfill
o Landfills comprise a series of lifts
o The final lift includes the landfill cover layer
 A bench (or terrace): is used when the height of the landfill
exceed 50 to 75 ft to maintain the slope stability of the landfill, for
the placement of surface water drainage channels and for the
location of landfill gas recovery piping
 Leachate is liquid that forms at the bottom of a landfill
 It is a result of the percolation of precipitation, uncontrolled
runoff and irrigation water into the LF
 It will also include water initially contained in the waste
 Contains a variety of chemical constituents derived from the
solubilization of the materials deposited in the LF and products
of the chemical and biochemical reactions
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93.  Definition of Landfilling Terms… (Fig.)
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93

94.  Definition of Landfilling Terms … (Fig.)
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95.  Definition of Landfilling Terms … (Fig.)
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96.  Definition of Landfilling Terms …
 Environmental monitoring: the collection and analysis of
water and air samples used to monitor the movement of
landfill gases and leachate at the landfill site
 Landfill closure is the steps that must be taken to close
and secure a landfill site once the filling operation has
been completed
 Post-closure care refers to activities associated with the
long-term maintenance of the completed landfill (30 - 50
years)
 Remediation refers to those actions necessary to stop
and clean up unplanned contaminant releases to the
environment
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96

97.  Definition of Landfilling Terms … (Fig.)
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97

98.  Definition of Landfilling Terms … (Fig.)
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99.  Composition of Landfill Gas
 Landfill gas comprises of:
o Principal gases
o Trace gases
1. Principal gases (present in large amounts):
o Produced from decomposition of the biodegradable OFMSW
o Include ammonia (NH3), carbon dioxide (CO2), carbon monoxide
(CO), hydrogen (H2), hydrogen sulfide (H2S), methane (CH4),
nitrogen (N2) and oxygen (O2)
o CH4 and CO2 are the principal gases produced from the
anaerobic decomposition of the biodegradable organic
components
o CH4 present in concentrations b/n 5 & 15% in air is explosive
o There is little danger of landfill explosion b/s only limited
amounts of O2 present when CH4 concentrations reach explosive
level
o CH4 mixtures in the explosive range can be formed if landfill gas
migrates off-site and get mixed with air
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100.  Composition of Landfill Gas…
2. Trace gases (present in very small amounts):
o Toxic and could present risks to public health
o Have two basic sources
 Brought to the landfill with the incoming waste (in
liquid form, but tend to volatilize)
 Produced by biotic and abiotic conversion reactions
within the landfill (associated with older landfills,
which accepted industrial and commercial wastes
containing VOCs )
o Many of the compounds are classified as VOCs
o The concentrations of VOCs have been extremely low
in newer landfills (disposal of Hazardous Wastes
banned)
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101.  Management of Landfill Gas
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102.  Final LF Cover Design …
 Barrier (Low K) Layer
o “Composite liner”: geomembrane, GCLs and low-K soil (clay)
o Low K prevents infiltration of water into waste: hydraulic barrier
o Restrict the movement of liquids into the LF and release of LF gas
through the cover
o Geomembrane: at least 0.5 mm thick
o Compacted clay: at least 60 cm with K≤10-7 cm/s
Subbase Soil Layer:
o Contour the surface of the LF
o Serve as a subbase for the barrier layer
o A minimum slope of 2% for effective gravity drainage
o compacted or graded native soil
o The lowermost layer
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103.  Final LF Cover Design …
 Gas vent layer
o Needed if waste will generate CH4 (explosive) or toxic gas
o Similar to drainage layer: 30 cm of sand or equivalent
geosynthetic may be used
o Connected to horizontal venting pipes (minimal number to
maintain cap integrity)
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104.  Landfill Stability
 LFs must be stable during construction, operations and after closure
 Some settlement is inevitable, however, if waste stays within the
containment system or if there are no mass movements down slope, LF is
considered stable
 The sliding of cover soils on the geomembrane barrier layer represents one
potential for failure surface
 Structural Characteristics
o SW in LF behaves quite similar as other fill material initially
o Waste must have a nominal angle of ~ 1.5:1 when placed in a LF
o Too steep slope angle cause waste to slip
o A completed portions will have 2.5:1 - 4:1 slopes (3:1 is the most common)
 Slope stability
o Consider able as size of LFs increase
o Uncontrolled dumping results in steep slopes & heights > 100 ft
o Slope stability analysis is part of LF design process
o Slope failure occurs if more waste is placed than anticipated which results
 Foundation-type failure
 Slopes becoming too steep
o Sign of slope failure  cracks open within the waste
o Determination of slope stability of LF needs analysis soil & waste mechanics
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105.  Landfill Settlement
 Landfill settles as:
o Decomposition of organic material & subsequent weight loss as LF gas
and leachate components
o Overburden mass increases as lifts are added and water percolates
into and out of the LF
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106.  LF Design Considerations
 Landfill design considers the ff important aspects:
o Layout of LF site
o Types of wastes that must be handled
o The need for a convenience transfer station
o Estimation of LF capacity
o Evaluation of the geology & hydrogeology of the site
o Selection of LF gas and leachate control facilities
o Layout of surface drainage facilities
o Aesthetic design considerations
o Environmental Monitoring facilities
o Public Participation
o Determination of equipment requirements
o Development of an operations plan
o Closure and postclosure care
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107.  Layout of Landfill Sites
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108.  LF Siting Restrictions
 Restrictions or bans of locating and operating new and existing
MSWLFs in six unsuitable areas
1. Airports: prohibit the placement of new, existing and lateral
expansions to existing MSWLFs near an airport because of dangers
from scavenging birds to aircraft
2. Floodplains: new, existing and lateral expansions at MSWLFs
located in the 100-year floodplain should not restrict the flow of the
100-year flood,reduce the temporary water storage capacity of the
floodplain or result in washout of SW so as to pose a hazard to
human health and the environment
3. Wetlands: prohibit the placement of a new landfill or expansion of
an existing landfill into or on a wetland
4. Fault areas: Prohibit the placement of a landfill within 200 feet of
an earthquake fault
5. Seismic impact zones: new and lateral expansions of MSWLFs are
prohibited in seismic impact zones, unless all containment
structures (liners, leachate collection systems, and surface water
control systems) are designed to resist the maximum horizontal
acceleration in lithified earth material for the site
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109.  LF Siting Restrictions…
6. Unstable areas (poor foundation conditions, areas susceptible to
mass movements and karst terranes): prohibit the placement of
new, existing and lateral expansions of MSWLFs in an area with
unstable soil unless engineering measures ensure the integrity of
structural components will not be disrupted
 Existing landfills which cannot meet the above requirements
should be closed within 5 years
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110.  LF Approval Regulatory Process
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111.  Preparation of site for Landfilling
 Site drainage is modified to route any runoff away from the intended LF
area
 Access roads and weighing facilities are constructed and fences are
installed
 Landfill bottom and subsurface sides are excavated and prepared
 Excavations are carried out over time, rather than preparing the entire
landfill bottom at once
 The bottom is shaped to provide drainage of leachate and a low-
permeability (clay, geomembrane) liner is installed
 Leachate collection and extraction facilities are placed within or top of the
liner
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112.  Preparation of site for Landfilling
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113.  Placement of SWs in LF
 Waste is placed in cells beginning along the compaction face, continuing
outward and upward from the face
 Wastes deposited by transfer vehicles are spread out in 50-60cm layers
and compacted
 Successive lifts are placed on top of one another until the final design
grade is reached
 As organic materials within the landfill decompose, completed sections
may settle. Refilling until the design grade is possible
 Final cover is designed to minimize infiltration of precipitation and to
route drainage away from the active section of landfill
 Finally, the site is landscaped and prepared for other uses
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114.  Placement of SWs in LF
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115.  Landfill Closure and Post closure Care
 What is to happen to a completed LF in the future
 Development of Long-Term Closure Plan
o Cover and landscape design
o Control of LF gases
o Collection and treatment of leachate
o Environmental monitoring systems
 Postclosure Care
 Routine inspection of the completed LF site
 Maintenance of the infrastructure
 Environmental monitoring systems
 Owner must demonstrate financial resources to provide long-term care
as part of LF licensing process
 Post-closure care is a major expense since it continues for 30- 40 Yrs
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116.  Sanitary landfill
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117.  LF Postclosure Care Requirements
 Primary requirements of postclosure care address:
o Maintaining the integrity and effectiveness of any final cover
systems
o Maintaining and operating the leachate collection system
o Monitoring GW and maintaining the GW monitoring system
o Maintaining and operating the gas monitoring system
o Quarterly inspection of cover for cracks, erosion, settlement &b
undesired vegetation
o Repair of cover to maintain grades if needed
o Inspection and repair of drainage and runoff control systems
o Leachate collection system inspection and cleaning
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118. PROJECT
 Design a sanitary land fill for hawassa university,
main compass deadline
 January 14/ 2023
 Number of group members
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119. AIR POLLUTION
Introduction
Atmosphere is:
 The layer of gases that surround the planet
 Very thin layer, relative to size of the planet
 Mixture of gases, also contains suspended solid and liquid particles
(aerosols) responsible for cloud formation: water drops nucleate on
them
• Aerosols are the “visible” components of the atmosphere
• Dust
• Sea-spray
• Microbes
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120.  Air is the gaseous atmosphere around us.
 Air pollution is any atmospheric condition in which
substances are present at concentrations high enough
above their normal ambient levels to produce a
measurable effect on man, animals, vegetation or
materials.
 Air pollution is substance added to the atmosphere
that can affect climate and harm organisms, including
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121.  Substances mean any natural or anthropogenic (man-
made) chemical compounds capable of being
airborne.
 They may exist in the atmosphere as gases, liquid
drops or solid particles.
 Air pollution comes from natural and human-
generated sources
 Natural sources include volcanoes, forest fires, pollen
and dust.
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122. Natural sources of air pollution
dust storms
fires
volcan
•Dust blown by wind
•Pollutants from wildfires and
volcanoes
•Volatile organics released by plants
•Withdrawing groundwater
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123. Artificial sources of air pollution
Human-caused air pollution includes:
 Point sources = specific spots where large
amounts of pollution are discharged
(stationary, Power and industrial plants)
 Non-point sources = diffuse, often made up of
many small sources (charcoal fires from
thousands of homes)
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124. Artificial sources of air pollution
Human-caused air pollution includes:
 Primary pollutants = emitted into troposphere in a
directly harmful form (soot, carbon monoxide)
 Secondary pollutants = produced via reaction of
substances added to the atmosphere with chemicals
already present in the atmosphere (ozone in
troposphere)
 Air pollution comes from many different activities such
as factories, power plants, dry cleaners, cars, buses,
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126.  Human activities can release substances into the air
which cause problems for humans and the environment.
 Air pollution contains suspended particles (particulate
matter, PM), which is a mixture of tiny particles and
liquid droplets that includes acids, organic chemicals,
metals and dust) and gases including carbon monoxide,
volatile organic compounds (VOCs), nitrous oxides,
sulfur dioxide and ozone.
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127.  Air supplies us with oxygen, which is essential for
the life of almost all plants and animals, including
humans.
 If air, undesirable for breathing, for the condition of
building and monuments exposed to it, or for animal
and plant life; it is said to be polluted.
 Air pollution also causes haze, reducing visibility in
national parks and wilderness areas as well as in our
cities.
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128.  Air pollution threatens the health of human beings,
trees, lakes, crops and animals as well as damages the
ozone layer and buildings.
 Air pollution can occur indoors or outdoors.
 Outdoor sources may be mobile (e.g. cars, trucks,
buses, trains, airplanes, boats) or stationary (e.g.
factories, refineries, power plants, bus garages).
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129. COMPOSITION OF THE ATMOSPHERE
 Atmosphere:
• Absorbs solar radiation
• Moderate s climate
• Transports and recycles water and other chemicals
 The atmosphere at any given instant is a complex mixture of
matter and energy:
 three phases of matter (gases, liquids, and solids) and
 several kinds of energy (electromagnetic energy, electrostatic
energy, molecular kinetic energies, winds and currents, sounds
and more).
 The atmosphere of earth is a layer of gases surrounding the
planet
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130. Composition of the Atmosphere
 The Global Carbon Cycle
 The Hydrological Cycle
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131. Composition of the Atmosphere
 permanent gases
 variable gases
 Traces of variable gases
 aerosols
• nitrogen, oxygen and argon
• water vapor
• carbon dioxide, methane, ozone, CFC, et al.
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132. Atmospheric composition
 78% nitrogen
 21% oxygen
 1% argon
 traces of other permanent
gases and variable small
amounts of:
 water vapor
 carbon dioxide
 methane
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133. 4/27/2023
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134.  The atmosphere protects life on Earth by absorbing
ultraviolet solar radiation, warming the surface through
heat retention (greenhouse effect), and reducing
temperature extremes between day and night (the
diurnal temperature variation).
 The material portion of the atmosphere is composed
primarily of gases— more than 99.9% of it is gases—
with liquids and solids held in suspension for varying
periods of time.
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135.  The common name given to the atmospheric gases used in
breathing and photosynthesis is air.
 Air also contains a variable amount of water vapor, on average
around 1%.
 Of the gases shown in the table nitrogen, argon etc remain in
relatively fixed proportions.
 The other gases like water vapor, carbon dioxide,, ozone are
added to and subtracted from the atmosphere by a variety of
natural processes.
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136.  Water is the only significant atmospheric liquid.
 Most clouds are composed of droplets of liquid water, so
are fogs, mist, rain and sea spray.
 The most important solids in the atmosphere are ice
crystals (most cirrus clouds are composed of ice crystals),
snow, hail, dust, sand, salt, pollen and the like.
 Human beings inhale oxygen and exhale carbon dioxide
and water vapor.
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137.  Green plants absorb carbon dioxide and emit oxygen and
water vapor.
 Both oxygen and carbon dioxide readily dissolve in the
waters that cover three-fourths of the earth’s surface—as
just readily released back into the atmosphere.
 While air content and atmospheric pressure vary at
different layers, air suitable for the survival of terrestrial
plants and terrestrial animals currently is only known to
be found in Earth's troposphere.
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138. Layers of the Atmosphere
 troposphere
 stratosphere
 mesosphere
 thermosphere
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139. Atmosphere consists of several layers:
• Troposphere = bottom layer, at Earth’s surface; 11 km
high; temperature decreases with altitude
• Stratosphere = next layer up (11–50 km); temperature
increases with altitude; contains “ozone layer”
• Mesosphere = third layer up (50–90 km); temperature
decreases with altitude
• Thermosphere = top layer (90–500 km); very thin air;
mostly lightweight elements; very hot; ionic radiation
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140. Atmospheric layers
Temperature
and other
characteristics
vary with
altitude.
Tropopause
marks
boundary
between
troposphere
and
stratosphere.
Ozone layer
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141. Ozone layer
 Not really a layer, but a region of higher-than-normal
ozone concentrations
 17–30 km altitude
 Absorbs ultraviolet (UV) radiation from sun,
protecting organisms on surface from radiation
damage
Atmospheric properties
 Atmospheric pressure = weight per unit area of air
being pulled down by gravity (is less at higher
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142.  Relative humidity = ratio of water
vapor air contains relative to how
much it could contain at that
temperature
 Temperature = air is warmed by the
sun; temperature varies with altitude,
location, time of day
 Gravity pulls most air molecules close
to Earth’s surface, so air density and
atmospheric pressure is greatest near the
surface.
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142

143. SOURCES AND CLASSIFICATION
 Air pollutant is any substance emitted into the air from
an anthropogenic, biogenic or geogenic source that is
either present in higher concentrations than the natural
atmosphere or it is not part of the natural atmosphere
and may cause a short-term or long-term adverse effect.
 Air pollutant sources can be categorized according to
the source, their number and spatial distribution, and the
type of emissions.
 Pollutants can be classified as primary or secondary
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144. 1/ PRIMARY AND SECONDARY POLLUTANTS
Primary pollutants
 Harmful substance that is emitted directly into the
atmosphere
Secondary air pollutants
 Harmful substance formed in the atmosphere when a
primary air pollutant reacts with substances normally
found in the atmosphere or with other air pollutants
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145. MAJOR AIR POLLUTANTS
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146. 4/27/2023
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148. THE MAJOR PRIMARY POLLUTANTS INCLUDE:
 particulate matter (PM),
 sulfur dioxide,
 nitrogen oxides,
 volatile organic compounds (VOCs),
 carbon monoxide and
 lead.
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150. PARTICULATE MATERIAL
 Any solid or liquid particles small enough to be
carried aloft in air.
 Consists of solid particles and liquid droplets small
and light enough to remain suspended in the air. Eg:
dust, soot, sulfates, nitrates; causes respiratory
damage.
 The most harmful forms of SPM are fine particles (PM-10, with an
average diameter <10 µm) and ultrafine particles (PM-2.5 µm).
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151.  Includes: soil particles, soot, lead, asbestos, sea salt and sulfuric
acid droplets.
 According to the EPA, SPM is responsible for about 60,000
premature deaths a year in the U.S.
 Dangerous for 2 reasons
 May contain materials with toxic or carcinogenic effects
 Extremely small particles can become lodged in lungs.
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152. NITROGEN AND SULFUR OXIDES
 Nitrogen Oxides
 Gases produced by chemical interactions between atmospheric
nitrogen and oxygen at high temperature
 Problems
Cause difficulty in breathing and acid
deposition
 Sulfur Oxides
 Gases produced by the chemical interactions between sulfur and
oxygen
 Causes acid precipitation
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153. CARBON OXIDES AND HYDROCARBONS
 Carbon Oxides
 Carbon monoxide (CO) and carbon dioxide (CO2)
 Greenhouse gases
 Hydrocarbons
 Diverse group of organic compounds that contain only hydrogen and
carbon (ex: CH4, methane)
 Some are related to photochemical smog and greenhouse gases
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154. SECONDARY POLLUTANTS
 Air pollution in urban and industrial areas is often
called smog.
 Photochemical smog is a noxious mixture of gases
and particles, produced when strong sunlight triggers
photochemical reactions in the atmosphere.
 It is an example of secondary pollutant
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154

155. FORMATION OF PHOTOCHEMICAL SMOG
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156. • Combination of words smoke and fog ═ Smog
• Combination of gases with water vapor and dust
• Forms when heat and sunlight react gases
(photochemical smog).
• Occurs often with heavy traffic, high temperatures,
and calm wind.
• The major component of photochemical smog is
ozone.
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157. OZONE
 Ozone is continuously created in the upper reaches of
the earth’ atmosphere from oxygen under
bombardment by hard radiation; and is created in the
troposphere by photochemical reactions of nitrogen
oxides and VOC.
 It is naturally unstable and breaks down into oxygen
over time.
 Tropospheric Ozone
 Man- made pollutant in the lower atmosphere
 Secondary air pollutant
 Component of photochemical smog
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158. STRATOSPHERIC OZONE
 Ozone at low altitudes = beneficial layer protecting us from UV
radiation
 Essential component that screens out UV radiation in the upper
atmosphere
 Man- made pollutants (ex: CFCs) can destroy it
 Ozone layer— 12 ppm in lower stratosphere—is enough to absorb
UV and protect us.
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158

159. Acid deposition
 Acidic deposition = deposition of acid-forming
pollutants from the atmosphere onto the Earth as acid
rain, acid fog, acid snow.
 One type of atmospheric deposition
 Caused by reaction of pollutants like SO2 and NO
with water, oxygen and oxidants resulting in sulfuric
acid or nitric acid
 Can have wide-ranging detrimental effects on the
environment
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160. Sources
• Natural events (e.g.,
volcanos and lightning)
and
• Human activities (e..g,
burning coal and internal
combustion).
• Sulfur and nitrogen react
with oxidizing agents
resulting in the formation
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160

161. Acid rain
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162. 4/27/2023
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163. Acid deposition
 Sulfuric acid droplets formed from SO2 and nitric
acid droplets formed from NO2
 Sulfates and nitrates aerosols (e.g., ammonium
(bi)sulfate and ammonium nitrate) formed from
reactions of sulfuric acid droplets and nitric acid
droplets with NH3, respectively
 Organic aerosols formed from VOCs in gas-to-
particle reactions.
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164.  Secondary pollutants – sulfates, nitrates, and organic
particles – can be transported over large distances,
such as hundreds and even thousands of miles.
 Deposition of these pollutants contributes to the
“acid deposition” (often called “acid rain”), with
possible damage to soils, vegetation, and susceptible
lakes.
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164

165. 2/ POINT, AREA AND LINE SOURCES
 According to number and spatial distribution includes:
 Point sources (stationary), area or multiple sources (stationary or
mobile), and line sources.
 Point sources characterize pollutant emissions from
industrial process stacks and fuel combustion facility
stacks.
 Area sources include vehicular traffic in a geographical
area as well as dust emissions from open-air.
 Line sources include heavily travelled highway facilities and the
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166. 4/27/2023
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166

167. 3. GASEOUS AND PARTICULATE EMISSIONS
 Air pollution sources can also be categorized according to
whether the emissions are gaseous or particulates.
 Examples of gaseous pollutant emissions include carbon
monoxide, hydrocarbons, sulfur dioxide, and nitrogen oxides.
 Examples of particulate emissions include smoke and dust
emissions from a variety of sources.
 Often, an air pollution source emits both gases and particulates
into the ambient air.
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167

168. CLASSIFICATIONS OF AIR POLLUTANTS
A. Criteria Pollutants
 There are 6 principal or “criteria” pollutants regulated by the
US-EPA and most countries in the world:
1. Total suspended particulate matter (TSP), with additional
subcategories of particles smaller than 10 μm in diameter
(PM10), and particles smaller than 2.5 μm in diameter
(PM2.5).
 PM can exist in solid or liquid form and includes smoke, dust,
aerosols, metallic oxides and pollen.
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169.  Sources of PM include combustion, factories, construction,
demolition, agricultural activities, motor vehicles and wood
burning. Inhalation of enough PM over time increases the risk
of chronic respiratory disease.
2. Sulfur dioxide (SO2). This compound is colorless but has a
suffocating, pungent odor.
 The primary source of SO2 is the combustion of sulfur
containing fuels (e.g., oil and coal).
 Exposure to SO2 can cause the irritation of lung tissues and
can damage health and materials.
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170. 3. Nitrogen oxides (NO and NO2). NO2 is a reddish-brown
gas.
 The primary source of this gas is vehicle traffic and it plays a
role in the formation of tropospheric ozone.
 Large concentrations can reduce visibility and increase the
risk of acute and chronic respiratory disease.
4. Carbon monoxide (CO). This odorless, colorless gas is
formed from the incomplete combustion of fuels.
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171.  Thus, the largest source of CO today is motor vehicles.
 Inhalation of CO reduces the amount of oxygen in the
bloodstream and high concentrations can lead to headaches,
dizziness, unconsciousness and death.
5. Ozone (O3). Tropospheric (“low-level”) ozone is a secondary
pollutant formed when sunlight causes photochemical
reactions involving NOX and VOCs.
 Automobiles are the largest source of VOCs necessary for
these reactions.
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172. 6. Lead (Pb). The largest source of Pb in the atmosphere
has been from leaded gasoline combustion, but with the
gradual elimination worldwide of lead in gasoline, air
Pb levels have decreased considerably.
 Other airborne sources include combustion of solid
waste, coal and oils, emissions from iron and steel
production and lead smelters and tobacco smoke.
 Exposure to Pb can affect the blood, kidneys and
nervous, cardiovascular and reproductive systems.
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173. B. Toxic Pollutants
 Hazardous air pollutants (HAPS), also called toxic air
pollutants or air toxics are those pollutants that cause or may
cause cancer or other serious health effects, such as
reproductive effects or birth defects.
 Examples of toxic air pollutants include benzene, which is
found in gasoline; tetrachlorethlyene, which is emitted from
some dry cleaning facilities; and methylene chloride, which is
used as a solvent and paint stripper by a number of industries.
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174. C. RADIOACTIVE POLLUTANTS
 Radioactive pollutant is an air pollutant that is both
geogenic and anthropogenic.
 Geogenic radioactivity results from the presence of
radionuclides, which originate either from radioactive
minerals in the earth’s crust or from the interaction of
cosmic radiation with atmospheric gases.
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174

175.  Anthropogenic radioactive emissions originate from
nuclear reactors, the atomic energy industry (mining and
processing of reactor fuel), nuclear weapon explosions,
and plants that reprocess spent reactor fuel.
 Since coal contains small quantities of uranium and
thorium, these radioactive elements can be emitted into the
atmosphere from coal-fired power plants and other
sources.
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175

176. D. INDOOR POLLUTANTS
 When a building is not properly ventilated, pollutants can
accumulate and reach concentrations greater than those
typically found outside.
 This problem has received media attention as “Sick Building
Syndrome”.
 Environmental tobacco smoke (ETS) is one of the main
contributors to indoor pollution, as are CO, NO, and SO2,
which can be emitted from furnaces and stoves.
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177. WHO ARE AT GREATEST RISK FROM INDOOR AIR POLLUTION?
 Children under 5 and the elderly
 Sick
 Pregnant women
 People with respiratory disorders or heart problems
 Smokers
 Factory workers
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177

178. Indoor air pollution
• In developed nations, the 2 biggest threats seem to
be:
• Cigarette smoke: lung cancer risk for smokers and
those inhaling secondhand smoke.
• Radon: naturally occurring colorless, odorless gas;
radioactive—seeps up from ground and collects in
buildings.
• It is estimated that this is the second leading cause of
lung cancer.
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178

179. Some important indoor air pollutants
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179

180.  Cleaning a house is an activity that can contribute to
elevated concentrations of harmful chemicals such as
VOCs emitted from household cleaners, paint and
varnishes.
 So, ventilation is important when cooking, cleaning,
and disinfecting in a building.
 A geogenic source of indoor air pollution is radon
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180

181. Indoor air pollution
 Indoor air pollution usually is a greater threat to human
health than outdoor air pollution.
 According to the EPA, the four most dangerous indoor
air pollutants in developed countries are:
 Tobacco smoke.
 Formaldehyde.
 Radioactive radon gas
 Particulates.
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181

182. INDOOR AIR POLLUTION - RADON
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183. How does the exchange of indoor air and outside air happen?
Infiltration—air exchange when doors and windows are closed:
Air moves through cracks around doors and windows, through
gaps around where plumbing and wires enter house, and through
the foundation-wall connection.
How does the exchange of indoor air
and outside air happen?
Natural ventilation: open the doors and windows to let fresh air in.
Forced ventilation: mechanical air handling systems brings in
outside air.
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183

184. HAWASSA UNIVERSITY, FACULTY OF TECHNOLOGY,
SCHOOL OF BIO-SYSTEMS AND ENVIRONMENT
ENGINEERING
EFFECTS OF AIR POLLUTION AND ITS MITIGATION
MEASURES
SEMARIA M.
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184

185. HEALTH EFFECTS OF AIR POLLUTION
 Numerous scientific studies have linked air
pollution to a variety of health problems
including:
(1) aggravation of respiratory and cardiovascular
disease;
(2) decreased lung function;
(3) increased frequency and severity of respiratory
symptoms such as difficulty in breathing and
coughing;
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185

186. (5) effects on the nervous system, including the brain
such as IQ loss (have impact on learning, memory
and behavior);
(6) cancer; and
(7) premature death.
 Some individuals appear to be at greater risk for
air pollution-related health effects. for example,
those with preexisting heart and lung diseases
(e.g., heart failure, asthma, emphysema and
chronic bronchitis)
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186

187. Respiratory effects
Symptoms:
 Cough
 Wheezing
 Phlegm
 Shortness of breath
 Chest tightness
Increased sickness and premature death from:
 Asthma
 Bronchitis (acute or chronic)
 Emphysema
 Pneumonia
 Premature aging of the lungs
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187

188. MAJOR COMPONENTS OF THE HUMAN RESPIRATORY SYSTEM
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188

189. CARDIOVASCULAR EFFECTS
Symptoms:
 Chest tightness
 Chest pain
 Palpitations
 Shortness of breath
 Unusual fatigue
Increased sickness and premature death from:
 Coronary artery disease
 Abnormal heart rhythms
 Congestive heart failure
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189

190. AIR POLLUTION ALSO DAMAGES OUR ENVIRONMENT
 Ozone is a gas that occurs both at ground-level and in
the Earth's upper atmosphere, known as the
stratosphere.
 At ground level, ozone is a pollutant that can harm
human health and the environment.
 Irritate respiratory system, reduces lung function by
damaging lining of lungs.
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190

191.  Causes burning of eyes, coughing and chest discomfort.
 Ozone can damage vegetation, adversely affect the growth
of plants and trees.
 These effect can reduce the ability of plants to uptake CO2
from the atmosphere.
 In the stratosphere, however, ozone forms a layer that
protects life on earth from the sun's harmful ultraviolet
(UV) rays.
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191

192.  UV light is part of the electromagnetic spectrum with
wavelengths just shorter than visible light
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192

193. Stratospheric ozone depletion
1 Cl
atom
can split
many O3
molecule
s
CFCs persist in the stratosphere.
They split oxygen atoms off ozone (O3) to form
oxygen (O2).
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193

194. OZONE DEPLETION IN STRATOSPHERE
 Ozone thinning/hole
 First identified in 1985 over
Antarctica
 Caused by human-produced
ozone-depleting substances,
including chlorofluorocarbons,
hydrochlorofluorocarbons,
(CFCs).
 Polar stratospheric clouds
 Enables Cl and Br to destroy ozone
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194

195. EFFECTS OF OZONE DEPLETION
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195

196.  Sulfur Dioxide and Particulate material
 Irritate respiratory tract and impair ability of
lungs to exchange gases
 Nitrogen Dioxides
 Causes airway restriction
 Carbon monoxide
 Binds with iron in blood hemoglobin
 Causes headache, fatigue, drowsiness, death
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197. ACID DEPOSITION
 Sulfur dioxide and nitrogen dioxide emissions react
with water vapor in the atmosphere and form acids that
return to the surface as either dry or wet deposition.
 Wet deposition (rain, snow or fog) or dry precipitation
(gas and particulates).
 pH scale
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197

198. HOW ACID DEPOSITION DEVELOPS
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199. EFFECTS OF ACID DEPOSITION
 Declining aquatic animal populations
 Thin-shelled eggs prevent bird
reproduction
Because calcium is unavailable
in acidic soil
 Forest decline
 Ex: Black forest in Germany (50% is
destroyed)
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200. Acid deposition and forest decline
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201. It eats away statues and buildings.
Acid deposition has killed these
conifer trees
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202. Acid deposition and aquatic systems
 Fish declines
 Undesirable species
Water
boatman
Whirligig
Yellow perch
Lake trout
Brown trout
Salamander
(embryonic)
Mayfly
Smallmouth bass
Mussel
6.5 6.0 5.5 5.0 4.5 4.0 3.5
pH
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203.  Acid rain can occur anywhere and, in some areas, rain
can be 100 times more acidic than natural precipitation.
 Some are carried by the wind, sometimes hundreds of
miles.
 In the environment, acid rain damages trees and causes
soils and water bodies to acidify, making the water
unsuitable for some fish and other wildlife.
 It also speeds the decay of buildings and statues that are
part of our national heritage.
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204. Air pollution: from local to global
LOCAL EFFECT
Soot and smoke
by heavy industry
URBAN &
MULTICITY EFFECT
Photochemical smog
CROSS BOUNDARY
AIR POLLUTION
Acid rain and acidic
deposition
GLOBAL AIR
POLLUTION ISSUES
Stratosphere ozone layer
Global warming
GLOBAL ENVIRONMENT
CHANGES
Global climate and
environmental changes
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205. o Eutrophication is a condition in a water body where
high concentrations of nutrients (such as nitrogen)
stimulate blooms of algae, which kills fish and causes
loss of plant and animal diversity.
o Air emissions of nitrogen oxides from power plants,
cars, trucks, and other sources contribute to the amount
of nitrogen entering aquatic ecosystems.
o This greatly accelerate eutrophication by increasing the
rate at which nutrients enter aquatic ecosystems.
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206.  Haze is caused when sunlight encounters tiny pollution
particles in the air.
 Haze obscures the clarity, color, texture, and form of
what we see.
 Some haze-causing pollutants are emitted from sources
such as power plants, industrial facilities, trucks and
automobiles and construction activities.
 Others are formed when gases emitted to the air (sulfur
dioxide and nitrogen oxides) form particles as they are
carried downwind.
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207. Effects of air pollution on wildlife
 Toxic pollutants in the air or deposited on soils or
surface waters, can affect wildlife in a number of ways.
 Like humans, animals can experience health problems
if they are exposed to sufficient concentrations of air
toxics over time.
 Studies show that air toxics are contributing to birth
defects, reproductive failure and disease in animals.
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208. Air pollution can also impact the Earth’s climate.
 pollutants affect climate in different ways, depending
on their specific properties and amount of time they
stay in the atmosphere.
 Any pollutant that affects the Earth’s energy balance is
known as a “climate forcer.”
 Some climate forcers absorb energy and lead to climate
warming, while others reflect the sun’s rays and prevent
energy from reaching the Earth’s surface, leading to
climate cooling.
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209.  Climate forcers can either be gases or aerosols (solid or
liquid droplets suspended in the air) and include ozone and
different types of particle pollution.
Greenhouse gas (GHG):
 A gas that traps heat in the atmosphere.
 The principal greenhouse gases affected by human activities
are:
 carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O),
ozone and fluorinated gases (hydro fluorocarbons [HFCs],
per fluorocarbons [PFCs], and sulfur hexafluoride [SF6]).
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210.  atmospheric greenhouse gases—like (CO2), (CH4),
and ozone—can trap this energy and prevent the heat
from escaping, somewhat like the glass panels of a
greenhouse.
 As a result, the Earth's atmosphere appears to be
trapping more of the sun's heat, causing the Earth's
average temperature to rise - a phenomenon known as
global warming.
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211. o Greenhouse gases (GHGs) are necessary to life because
they keep the planet’s surface warmer than it would
otherwise be.
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212.  However, as the concentrations of these gases continue to
increase in the atmosphere, largely due to the burning of fossil
fuels like coal and oil, the Earth’s temperature is climbing above
past levels.
 Many scientists believe that global warming could have significant
effects on human health, agriculture, water resources, forests,
wildlife, and coastal areas.
 Sulfates, nitrates and organic carbon—are largely reflective and
therefore have a net cooling impact on the atmosphere
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213. o The longer a pollutant stays in the atmosphere, the
longer the effect associated with that pollutant will
persist.
o Some climate forcing pollutants stay in the
atmosphere for decades or centuries after they are
emitted, meaning today’s emissions will affect the
climate far into the future.
o Pollutants like CO2 tend to accumulate in the
atmosphere as a result their net warming effect
continues over time.
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214.  ozone and BC, remain in the atmosphere for shorter periods
of time, so reducing emissions of these pollutants may have
beneficial impacts on climate in the near term.
 These short-lived climate forcers originate from a variety of
sources: the burning of fossil fuels and biomass, wildfires,
and industrial processes.
 Short-lived climate forcing pollutants and their chemical
precursors can be transported long distances and may
produce harmful warming effects in sensitive regions such
as the Arctic.
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215. o Some of the changes that are predicted due to climate change
are:
o hot extremes and droughts will become more frequent
o heavy precipitation events, storms, hurricanes and flooding will
become more frequent
o sea levels will rise and there will be significant loss of land
o weather patterns will change
o thousands of animal species and plants will die and become
extinct
o food and water scarcity will cause civil conflict
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218. 4/27/2023
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219. 4/27/2023
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220. MITIGATION MEASURES OF AIR POLLUTION
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221. Clean Air Act legislation
o Clean Air Act of 1970:
• Set stricter standards than previous laws
• Imposed emissions limits
• Provided research funds
• Enabled citizens to sue violating parties
o Clean Air Act of 1990:
• Strengthened previous regulations
• Introduced emissions trading for sulfur dioxide
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222. The Clean Air Act
o Authorizes EPA to set
limits on amount of
specific air pollutants
permitted
o Focuses on 6 pollutants:
• lead, particulate
matter, sulfur dioxide,
carbon monoxide,
nitrogen oxides, and
ozone
o Act has led to decreases!
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223. Recovery of Ozone Layer
o Montreal Protocol (1987)
• Reduction of CFCs
• Started using HCFCs
o Phase out of all ozone destroying chemicals is
happening globally.
o Satellite pictures in 2000 indicated that ozone layer
was recovering.
o Full recovery will not occur until 2050
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224. Reducing Outdoor Air Pollution
o There are a number of ways to prevent and control air
pollution from motor vehicles.
• Because of the Clean Air Act, a new car today in the
U.S. emits 75% less pollution than did pre-1970 cars.
• There is an increase in motor vehicle use in
developing countries and many have no pollution
control devices and burn leaded gasoline.
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225. o How to help stop Global Warming?
o Reduce
o The amount of energy you consume and start using
renewable energy sources, such as wind power and
solar power.
o Reuse
o By using products made with recycled materials. Make
or buy a compost bin to use your organic waste as
fertilizer for your trees, shrubs and garden.
Recycle
o All materials to your best ability in your local area and
purchase Carbon Offsets.
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226. Reducing indoor air pollution
o Buy and use low-toxicity products
o Provide good ventilation
o Limit exposure to plastics, pesticides, cleansing fluids
(put in garage)
o Test home for radon
o Test drinking water for lead from pipes
o In developing world, provide ventilation, install clean-
burning stoves, shift to gas
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227. for Rn
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228. PREPARE TERM PAPER ON:
1. Effect of global warming (positive and negative)
(Tech/0002/04,Tech/0042/04,Tech/2022/03,Tech/0081/04,Tech/0101/04,
Tech/0108/04,Tech/0129/04, Tech/0154 /04
2. Industrial plant location and city planning
(Tech/0186/04,Tech/0206/04,Tech/0227/04,Tech/0230/04,Tech/211/03,Tech/0360/
04,Tech/0403/04,Tech/0418/04,Tech/0439/04,Tech/055 /04, Tech/0458 /04 )
3. Emission Trading Policy (Tech/0474/04,Tech/0481
/04,Tech/0515/04,Tech/0539/04,Tech/0568/04,Tech/0595/04,Tech/0614/04,Tech/0
615 /04, Tech/0616 /04
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229. 4. National Ambient Air Quality Standards
(Tech/0647/04,Tech/0652/04,Tech/0679/04,Tech/0731/04,Tech/0732/04,Tech/0738/04,
Tech/0816/04,Tech/0867/04,Tech/0885/04,Tech/0872/04 )
5. Montreal protocol(Tech/0130/04, Tech/0941/04,Tech/1020/04,
Tech/1050/04,Tech/1133/04,Tech/1170/04,Tech/1195/04,Tech/1212/04,Tech/1228
/04,Tech/1240 /04)
6. Air quality and emission standard adopted by EPA
(Tech/1246 /04, Tech/1248/04, Tech/1350 /04, Tec/2519/03, Tech/1381 /04,
Tech/1473/04, Tech/1493/04,Tech/1461/03,Tech/1550/04, Tech/1886/04)
7. Industrial plant location and city planning (Tech/1714
/04,Tech/1783/04, Tech/1785/04,Tech/1786/04,Tech/1814/04,Tech/1820 /04,
Tech/2750/03, Tech/1823/04,Tech/1821/04, Tech/1851/04)
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230. Thank you!
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