solid waste management
TRANSCRIPT
SOLID AND HAZARDOUS WASTE MANAGEMENT
Hawassa University
Institute of Technology
School of Bio-Systems & Environment Engineering
CHAPTER 1
2
Chapter 1: Solid Waste Management
Chapter 2:Solid Waste Generation and Collection
Chapter 3:Solid Waste Handling, Storage and Processing at the Source
Chapter 4:Collection Methods of Solid Waste
Chapter 5:Solid Waste Separation, Processing and Transformation
Chapter 6: Solid Waste Transport and Transfer and Disposal
Chapter 7:Hazardous Solid Wastes Management
Chapter 8:Urban And Rural Sanitation
Course contents
3
The term ‘waste’ has a different meaning for different
people. In general, Waste is any form of liquid, semi-liquid,
solid, or gaseous material which no longer serves the
purpose for which it was originally intended.
Solid wastes are all the wastes arising from human and
animal activities that are normally solid and are discarded
as useless or unwanted.
However, ‘unwanted’ is subjective, as it could be of value
for another person under different circumstances or even
in a different culture.
From the days of primitive society, humans and animals
have used the resources of the earth to support life and
dispose of wastes.
4
Disposal is any operation which may lead to resourcerecovery, recycling, reclamation, direct re-use or alternativeuses.
In early times, the disposal of human and other wastes did
not pose a significant problem, because the population was
small and the amount of land available for the assimilation
of wastes was large.
Problems with the disposal of wastes can be traced from
the time when humans first began to congregate in tribes,
villages, and communities and the accumulation of wastes
became a consequence of life.
5
Factors That Contribute To the Solid Waste Problem
Rapid Urbanization
oUrban development
oNew township development
oDevelopment of housing estate
oIndustrial
Changing Lifestyle
oStandard of living
oBuying power
Consumption Patterns
o Eating habits
o Buying power
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Inadequate Government Policy
oLeak of enforcement
oNo uniformity in regulations/
procedures
oDifferent methodology used
oNo comprehensive laws and
regulations
oLeak of Disposal area
Spiraling Population Growth
Rate
oPopulation Growth rate
oInternal migration of population
oExternal migration of population
Public Indifference
• People don’t care
• People believe that it’s government
sole responsibility
• Propensity of the people to generate
waste and just throw it anywhere
• Lack of appreciation of the
importance of waste
avoidance/reduction, segregation
and composting
• Inefficient collection of garbage
• Non-operation of a good disposal
facility
Factors That Contribute To the Solid Waste Problem…
7
Solid waste today contains many materials such as
plastics that are not readily degradable and toxic
materials, primarily various types of chemical waste
produced by industry.
Similarly, the amount of hazardous waste generated has
been undergoing dramatic change. In addition, industries
increase their annual discharges of toxic chemicals
directly into the environment.
The problem became larger with more people generating
more and a variety of waste (chemical, liquid, solid,
nuclear, and hazardous).
Thus, a variety of methods must be used to manage the
waste.
8
Consumption is greatly
increasing in developing
nations- Rising standard of
living, more packaging,
poor-quality goods.
Wealthy consumers often
discard items that can still
be used.
Poor people support
themselves by selling items
they scavenge from dumps.
9
When solid wastes are disposed off on land in open dumps
or in improperly designed landfills (e.g. in low lying areas),
it causes the following impact on the environment.
Ground water contamination by the leachate generated by the waste dump
Surface water contamination by the run-off from the waste dump.
They produce a good breeding place for flies, hence create a favorable
conditions for food contamination by flies and other fly-borne diseases.
Provide food and shelter for rats and mice, which are destroyers and
contaminants of food and other goods.
Under certain conditions, may create suitable breeding place for
mosquitoes. Subsequently bring in the problem of mosquito-borne
diseases, (e.g. malaria, filariasis, etc)
May cause nuisances- which create aesthetic problem, (e.g. looks
unpleasant and has bad smell, etc.)
May attract dogs, cats and other scavengers.
May cause fire hazards by instantaneous combustion
10
In low-income countries, most of the
collected municipal solid waste is
dumped on land in a more or less
uncontrolled manner.
Such inadequate waste disposal
practices create serious environmental
problems affecting not only the health
of humans and animals, but also giving
rise to serious economic and other
welfare losses.
In cities of developing countries, the
urban poor suffer most from the life-
threatening conditions of deficient
Solid Waste Management.
Polluted open sewer
Open street site dump
11
Solid waste management may be defined as the discipline
associated with the control of generation, storage, collection, transfer
and transport, processing, and disposal of solid wastes in a manner
that is in accordance with the best principles of public health,
economics, engineering, conservations , and that is also responsive
to public attitudes.
Integrated solid waste management (ISWM) is the term applied to
all of the activities associated with the management of the
community’s waste.
It is the selection and application of suitable techniques,
technologies and management programs to achieve specific
waste management objective and goals
The basic goal of ISWM is to manage community waste in a
manner that meets public health and environmental concerns and
the public’s desire to reuse and recycle waste material.
14
The identification of waste management as integral to
sustainable urban development is increasingly recognized by
the international aid and development community.
The United Nations Conference on Environment and
Development stressed that ‘...solid waste production should be
minimized, reuse and recycling, maximized, environmentally
sound waste disposal and treatment promoted and waste
service coverage extended .’
Environmentally sound and resource efficient approaches to
the problem of growing solid waste quantities, and considers
waste management as a crucial component of human policies
and programs.
15
In Ethiopia, particularly in Addis Ababa, an agency is responsible
for the collection and disposal of solid wastes for the city of Addis
Ababa.
The estimated solid waste generation of an Addis Ababa resident
was about 0.24 kilogram per capita per day and a total of 163,200
tons per annum.
The existing collection capacity covered less than 50 percent of
the total wastes generated. The remaining wastes were dumped
along the streets, on vacant plots, along streams, in ditches,
bridges, etc.
Solid waste management services in other urban centers of
Ethiopia is the responsibilities of municipalities and urban
centers.
Most of them have no institutional set up and resources for
discharging their duties effectively. This is aggravated by the low
priority usually accorded to sanitation activities.
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What is sustainability in relation to waste management?
Sustainability implies looking at the whole waste
management system, including waste prevention and
resource recovery and searching for a system that best suits
the society, economy and environment in question.
Institutional issues
• Need for policy changes (e.g. legislation) in order to improve
effective and efficient solid waste management.
• Need to set up functional structures at the grassroots level to
work with communities and institutions
• Need to try to link the formal and informal solid waste
management sector through waste collection schemes.
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What is sustainability …..?
Technical issues• Need to focus more on recycling and resource recovery as a
common practice
• Need to focus on environmental impacts (e.g. surface and ground
water) of solid waste around dump sites
• Need for proper management of hospital and hazardous waste
• Need for relevant training and equipment for hospital waste
handlers
Social issues• Need to work with informal waste actors such as scavengers at
dump sites
• Need for health education so as to create awareness regarding
solid waste management
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What is sustainability …..?
It is necessary to establish
integrated and sustainable
systems of solid waste
management that meet the
needs of the entire urban
population, including the poor.
The essential condition of
sustainability implies that waste
management systems must be
absorbed and carried by the
society and its local
communities.
National and local factors influencing the
core concepts of the waste management in
which solid waste elements diminish in
priority from top to bottom.
19
In its scope, solid waste management includes all
administrative, financial, legal, planning, and engineering
functions involved in solution to all problems of solid wastes.
Many people feel that solid waste management is a simple
affair - simply putting waste into a vehicle and unloading it at
a dump.
If this were true, then why do so many towns suffer from
uncollected refuse blocking streets and drains, harboring flies
and rats, and degrading urban environments?
The preparation and management of a good solid waste
management system needs inputs from a range of
disciplines, and careful consideration of local conditions.
20
The main goal of solid waste management are:
1. To protect the health of the urban population, particularly
that of low-income groups who suffer most from poor
waste management.
2. To promote environmental conditions by controlling
pollution (including water, air, soil, and cross-media
pollution) and to ensure the sustainability of ecosystems
in the urban region.
3. To support urban economic development by providing the
required waste management services and guaranteeing
the efficient use and conservation of valuable materials
and resources.
4. To generate employment and income.
21
Key to integrated solid waste management is the
development of a waste management hierarchy, integrating
widespread elements of national and regional policy.
The hierarchy classifies waste management operations
according to their environmental or energy benefits:
1.Prevent the production of waste or reduce the amount generated.
2.Reduce toxicity or negative impacts of the waste generated.
3.Reuse the materials recovered from the waste stream in their current
forms.
4.Recycle, compost or recover materials for use as direct or indirect inputs
for new products.
5.Recover energy by incineration, anaerobic digestion or similar processes.
6.Reduce the volume of waste prior to disposal.
7.Dispose of residual solid waste in an environmentally sound manner,
generally in landfills.
22
The sources of solid wastes are dependent on
1. The socio- economic and
2. Technological levels of a society
A small rural community may have known types of
solid wastes from known sources (i.e. the wastes are
more homogenous).
Wastes from industrial and mining areas are also
more homogenous.
Urban communities (metropolitan cities) have many
sources (The wastes are more heterogeneous).
23
Five main categories of solid waste :
1. Municipal Solid Waste : waste from the household, commercial wasteand institutional waste.
2. Agriculture waste : Wastes and residues resulting from diverseagricultural activities include plant residue and animal waste. Foodprocessing waste is consider as agriculture waste.
3. Industrial waste :comprises waste from industrial processes
4. Hazardous waste: Wastes or combination of wastes that pose asubstantial presence or potential hazard to human.
5. Medical waste: includes hazardous (clinical waste) and non-hazardouswaste.
• Clinical wastes are any waste consist human tissue, blood or other bodyfluids, excretion include infectious waste.
24
Sources of solid wastes in a community are:
1.Residential: generated from livinghouseholds/ domestic, generallycontain non-hazardous solid wastes;kitchen waste, and ash
2.Agricultural: solid wastes due toagricultural activities such as foodresidues, animal dung, cropresidues, etc. Such wastes areusually non-hazardous.
3.Commercial: wastes generated frombusiness establishments Such foodestablishments, shops, etc, that generategenerally non-hazardous waste such aspaper, cardboard, wood, metals andplastic.
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4. Industrial wastes: from various types ofindustrial processes. The nature of thewaste depends on the type of industry andkind of raw material involved. There maybe toxic and hazardous wastes that haveadverse effects to the environment.
5. Institutional solid waste: generating from public and governmentinstitutions: offices, religious institutes, schools, universities, etc.generally not hazardous.
6. Hospital solid wastes: discarded, unwanted solid wastes from hospitals.It consists of both non-hazardous and hazardous waste.
7. Construction and Demolition Wastes
8. Municipal Services waste
9. Treatment Plant Sites waste
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Types of solid wasteslocations where wastes are
generated
Source
Food wastes, paper, cardboard,
plastics, textiles, leather, yard
wastes, wood, glass, metals, ashes,
special wastes (e.g., bulky items,
consumer electronics, goods,
batteries, oil, tires), and household
hazardous wastes
Single and multifamily dwellingsResidential
Industrial process waste, scrap
materials, etc. Non - industrial
waste including food wastes,
construction and demolition
wastes, rubbish, ashes , hazardous
wastes, ashes, special wastes
Light and heavy
manufacturing, fabrication,
construction sites, power and
chemical plants
Industrial
Sources and Types of Solid Wastes within a Community
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Types of solid wasteslocations where wastes are
generated
Source
Paper, cardboard, plastics,
wood, food wastes, glass,
metals, special wastes,
hazardous wastes
Stores, hotels, restaurants,
markets, office buildings, etc.
Commercial
Same as commercialSchools, hospitals, prisons,
government centers
Institutional
Wood, steel, concrete, dirt,
etc.
New construction sites, road
repair, renovation sites,
demolition of buildings,
broken pavement
Construction and
Demolition
Sources and Types of Solid Wastes within a Community (Cont’d)
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Sources and Types of Solid Wastes within a Community (Cont’d)
Types of solid wastesTypical facilities, activities, locations where wastes are generated
Source
Street sweepings; landscape and tree trimmings; general wastes from parks, beaches, and other recreational areas; sludge
Street cleaning, landscaping, parks, beaches, other recreational areas, water and wastewater treatment plants
Municipal Services (including treatment facilities)
Spoiled food wastes,agricultural wastes,rubbish, hazardous waste.(e.g. pesticides, herbicides)
Field and row crops, orchards, vineyards, dairies, feedlots, farms, etc.
Agricultural
Definition of some types of solid wastes
Refuse: It is a general name given to all wastes exceptliquid waste. It includes:
a. Putrescible / Bio-degradable: can be decomposed rapidlyby bacteria. Example: paper, wood, fruits and others.
b. Non- putrescible / Non-biodegradable: cannot bedecomposed wastes. Example: plastics, bottles, oldmachines, cans, Styrofoam containers and others.
Garbage: designates putrescible wastes resulting from thegrowing, handling, preparation, cooking, and serving offood. It attracts insects, rats and rapidly decomposes withproduction of unpleasant odor. Example: Vegetables,fruits, bones, bread, injera etc.
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Definition of some types of solid wastes…
Rubbish: This term includes all non-putrescible refuse exceptashes. There are two categories of rubbish:
a. Combustible: This material is primarily organic in nature andincludes items such as paper, cardboard, wood and bedding.
b. Non-combustible: This material is primarily inorganic andincludes tin cans, metals, glass, ceramics, and other mineralrefuse.
Ashes: an incombustible material that remains after a fuel orsolid waste has been burnt.
Infectious wastes: are wastes that contain or carry pathogenicorganisms in part or in whole such as wastes from hospitalsand biological laboratories soiled with blood or bodily fluids.
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Definition of some types of solid wastes…
Special wastes: are wastes from residential and commercialsources that includes.
- Bulky items (large worn out or broken household,commercial, and industrial items like, Furniture, lamps,bookcases, filing cabinets, etc.)
- Consumer electronics (includes worn-out, broken, and otherno- longer wanted items such as radios, stereos, TV sets.
- White goods (large worn – out a broken household,commercial, and industrial appliances such as stoves,refrigerators, dishwashers, clothes washers and dryers)
Organic waste: Food waste, paper, cardboard, plastics,textiles, rubber, leather, wood, yard wastes.
Inorganic waste: Glass, crockery (cups, plates, etc) tin cans,aluminum, and other metals.
Dead bodies: dead animals like dogs ,cows, donkey etc.31
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Composition is the term used to describe the individual
components that make up a solid waste stream and their relative
distribution , usually by percent by weight.
Information on the composition of solid wastes is important in
evaluating
1. equipment needs,
2. systems required and
3. manage program and plans.
The residential and commercial portion makes up about 50 to
75 percent of total Solid waste generated in a community. The
actual percentage distribution will depends on:
1. The extent of construction and demolition activities
2. The extent of the municipal services provided
3. The types of water and wastewater treatment process that
are used
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ComponentPercent by Weight Moisture percent
Range Typical Range Typical
Organic
Food wastes 6 – 26 15 50 – 80 70
Paper 25 – 45 40 4 – 10 6
Cardboard 3 – 15 4 4 – 8 5
Plastics 2 – 8 3 1 – 4 2
Textiles 0 – 4 2 6 – 15 10
Rubber 0 – 2 0.5 1 – 4 2
Leather 0 – 2 0.5 8 – 12 10
Yard wastes 0 – 20 12 30 – 80 60
Wood 1 – 4 2 15 – 40 20
Misc. organics
In-organics
Glass 4 – 16 8 1 – 4 2
Tin cans 2 – 8 6 2 – 4 3
Aluminum 0 – 1 1 2 – 4 2
Other metal 1 – 4 2 2 – 6 3
Dirt, ash etc 0 – 10 4 6 – 12 8
The percentage distribution values for the components in Solid waste vary with
1. Location
2. Season
3. economic conditions
4. population
5. Social behavior
6. Climate
7. Market for waste materials
8. Other factor
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A. Physical composition of solid wastes
Knowing the characteristics the physical component of acommunity solid waste is important for the following purposes:
- for the selection and operation of equipment and facilities
- to assess the possibility for resource of energy recovery
- to design and analyze disposal facilities
Ways for physical composition Analysis
Individual component study
- Analyze the components of municipal solid waste by type
- Sorting and separation of each and every component is necessary
- Samples each of the heterogeneous refuse of municipal solid waste
- Should be representative (at all seasons of the year)
- Statistical produces (representativeness and randomization)
35
The individual component study involves to achieve thepresent composition of solid waste by volume and by weight.
Moisture content
Moisture content is determined as follows:
The sample is weighed as received (“wet weight”) and then allowed tostand until it is air-dried, i. e. until its moisture content is equal tothat of the ambient air.
The moisture content is then obtained by the following formula:
Mc = Ww – Wd × 100
Ww
where: Mc = moisture content (in %)
Ww = wet weight of sample
Wd = dry weight of sample
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B. Chemical composition
Information on the chemical composition of solid wastes isimportant in evaluating alternative processing and recoveryoptions. These studies include the assessment of moisturecontent, volatility, ash content, etc.
The moisture content of municipal solid wastes variesdepending on composition of the waste, the season of theyear, humidity and weather condition.
For example, the feasibility of combustion depends on thechemical composition of solid waste.
C. Biological properties
The most important biological characteristic of the organicfraction of municipal solid waste is that almost all of theorganic components can be converted biologically to gasesand relatively inert organic and inorganic solids.
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Various estimates have been made on the quantity of solidwaste generated and collected per person per day. Theamount of municipal solid waste collected is estimated tobe2.7 kg/capita/day, of which about 0.6 kg is residential.
Averages are subject to adjustment depending on manyfactors: time of the year; habits, education, and economicstatus of the people; number and type of commercialindustrial operations; whether urban or rural area; andlocation.
Each community should be studied and actual weighingmade to obtain representative information for designpurposes. Community wastes are not expected to exceed1000 kg/capita/year.
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With the emphasis being placed on source reduction suchas less packaging, waste recovery and recycling such asof paper, metals, cans, and glass, the amount of solidwaste requiring disposal is reduced.
The volume occupied by solid waste under certainconditions determines1. the number and size or type of refuse containers,
2. collection vehicles, and
3. transfer stations.
Transportation systems and land requirements fordisposal are also affected.
39
Determination of Solid Wastes in the FieldBecause the heterogeneous nature of solid wastes, determination of the
composition is not an easy task. More generalized field proceduresbased on common sense and random sampling technique have evolvedfor determining composition
The procedure for residential Solid Wastes can be: The load is first quartered One part is then selected for additional quartering unit a sample size
of about 200 lb is obtained It is important to maintain the integrity of each selected quarter
regardless of the odor or physical decay make sure that all the components are measured
The field procedure for component identification for commercial andindustrial waste involves the analysis of representative waste samplestaken directly from the source, not from a mixed waste load in acollection vehicle. Due to the fact that these wastes are so variable.
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1.4 Quantities and Volume of Solid Waste…
41
Some of material that can be recovered from solid wastes are:Aluminum, Paper, Plastics, Glass, Ferrous Metals (Iron and Steel),Nonferrous waste, Yard waste collected separately, Constructionand demolition wastes.
Recycling is the best way to solve solid waste managementproblem. This process exists in all cities . However, the recyclingsystem differs from developing countries and developedcountries.
Developed countries have well organized source separation andrecycling system while in the developing countries the system ofrecycling is not effective because it is still in the hands of informalsectors.
1.4 Quantities and Volume of Solid Waste…
Developing Countries Have Recycling System Starting FromCurbside Collection System. Separate Colored Collections Binsare Provided to Deposit Separate Waste Material
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1.4 Quantities and Volume of Solid Waste…
These Sorting Facilities are Well Organized and Materials areSeparated for Further Processing
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1.4 Quantities and Volume of Solid Waste…
T
These Scavengers Collect the Recyclables and Separate in their Own Premises
45
1.4 Quantities and Volume of Solid Waste…
Recyclables Collected from Scavengers are Deposited in One Place
46
1.4 Quantities and Volume of Solid Waste…
47
In terms of solid waste management planning, knowledge offuture trends in the composition of solid waste and quantities areof great importance.
Food Waste The quantity of residential food waste collected has changed
significantly over the years as a result of technical advancesand change in public attitude.
Two technological advances that have had a significant effectare the development of the food processing and packagingindustry and the use of kitchen food waste grinders.
The percentage of food waste, by weight, has decreased fromabout 14 percent in the early 1960s to about 9 percent in 1992.
48
Paper andCardboard The percentage of paper and cardboard found in MSW has
increased greatly over the past half century , rising from about 20percent in the early 1940s to about 40 percent in 1992 .
It is expected that use of paper and cardboard will remain stable forthe next few year.
YardWastes The percentage of yard waste has also increased significantly, due
primarily to passage of laws that prohibit burning of yard wastes.
By weight, yard waste currently accounts for about 16 to 24 percentof the waste stream.
Environmental conditions such as droughts have also affected thequantities of yard wastes collected in certain locations
49
Plastics The percentage of plastics in solid waste has increased
significantly during the past 50 years
The use of plastics has increased from almost non-measurable quantities in the early 1940s to between 7 and8 percent, by weight, in 1992.
It is anticipated the use of plastic will continue toincrease, but at a slower rate than during the past 25 years.
50
The proper storage at the point of generation, collection and
disposal of the solid waste is part of the environmental health
service program, which must be accomplished effectively in a
community.
The public health and ecological reasons for proper management of
solid wastes are:
an attractive media for the growth and multiplication of flies, and
hence, may involve all diseases which are transmitted by flies,
(e.g. typhoid fever, cholera, dysenteries. etc);
a suitable breeding place for mosquitoes, subsequently bringing
the problem of mosquito-born diseases;
a good harborage for rats, which can be an economic as well as
health problem;
from aesthetic point of view , such as bad odor , unsightly
conditions etc;
pollution and contamination of air , land and water;
possible fire hazards by instantaneous combustion