2. Presentation Outline
Introduction
History of waste management
Background
Classification of different waste solid wastes
PHI significance of Solid Waste
Factor influencing SWM
Collection and transportation SW
SW Disposal and Management
Benefits of SWM
Challenges during SWM
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3. History of Waste management
Throughout most of history, the amount of waste
generated by humans was insignificant due to low
population density and low societal levels of the
exploitation of natural resources.
Common waste produced during pre-modern times
was mainly ashes and human biodegradable
waste, and these were released back into the
ground locally, with minimum environmental
impact.
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4. Modern Era
onset of industrialisation and the sustained urban growth of large
population centre the build-up of waste in the cities caused a
rapid deterioration in levels of sanitation and the general quality of
urban life.
The streets became choked with filth due to the lack of waste
clearance regulations
Calls for the establishment of a municipal authority with waste
removal powers occurred as early as 1751, when Corbyn Morris in
London proposed that "...as the preservation of the health of the
people is of great importance, it is proposed that the cleaning of
this city, should be put under one uniform public management,
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5. Introduction
Operation Definition;
waste :Any item or substance for which the immediate owner can
find no particular use and of which disposal is necessary.
Solid waste: Includes refuse, garbage, sludge e.t.c generated from
waste or water or water treatment plant or air pollution control
facility.
Leachate: Liquid resulting from precipitation that percolates
through landfill and contains H2O, decomposed waste matter,
bacteria and chemical substances.
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6. Con’t Intro….
Refuse: All biodegradable and non-biodegradable material that is
discarded or rejected and includes but not limited to garbage,
rubbish, ash, sweepings, dead animals etc.
Garbage: Biodegradable waste of both animal and vegetable
matter which results from where food is stored, prepared or served.
Biodegradable Materials: Waste material capable of being broken
down, usually by bacteria into basic elements e.g. food remains,
paper e.t.c.
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7. Con’t… Intro….
Infectious waste: Waste generated by health units, pharmacies,
labs, and drug shops; these include surgical, obstetric
gynecological and biological wastes from patients, isolation,
serum, drugs that can be infectious to humans.
Municipal solid waste: Non hazardous waste generated in
houses, commercial areas, industries & institution excluding
wastes from industrial processing plants, agricultural wastes,
mining & sewage sludge.
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8. Con’t Intro
Definition of SWM
Is processes undertaken from solid waste generation, storage,
transportation and disposal.
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9. BACKGROUND OF SOLID WASTE
MANAGEMENT IN KAMPALA
Each household in Uganda generates approximately 1 tonne of Domestic Waste
per year.
In Kampala city alone Domestic waste generation rates range between o.5 -1.1
Kgs per day. With a population estimates at 1.5 million,
The estimate of waste per capita generation per day is 0.5kg giving us 750 Tonnes
generated per day.
Solid waste generation is higher among high income earner population.
Average collection is 45-50% of this and so on daily basis collection amounts to
375 tones.
In composition, plastics underwhich polythene falls account for 1.6% with the
highest being 73.8% for vegetable matter with the rest being tree cuttings, glass,
metals, paper.etc. Kampala city A. generates ~800tones of domestic waste per
day
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10. Classification of SW
Solid waste can be classified under the following categories
Domestic wastes, wastes generated from household
E-Waste, informal name for electronic products nearing the end of their
"useful life."
Industrial wastes(can be processing or manufacturing)
Street wastes and litter(dust, litter, motor parts, fallen leaves, waste
papers, plastic bags, maize cobs)
Commercial wastes from big establishments like bookshops,
supermarkets, hotels, hostels, training institutions and shops
Garden/ agricultural wastes; town e.g cut grass, maize cobs, leaves of
trees, twigs from trimmed flowers, fallen twigs from trees e.t.c
Hospital wastes, HFs,pharm, labs, and drug shops; e.g. biological
wastes from patients, isolation, serum, drugs that can be infectious to
humans
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11. PHI significance of SWM
High Disease Burden e.g. Diarrhoeal illnesses injuries e.t.c
Open burning of solid waste poses a potential risk to air pollution
Occupational Hazards especially those working at the waste
management departments
Environmental Pollution
Increased costs of Solid waste management
Contamination of underground water
SW can provide breeding grounds for vectors and rodents such as
flies, cockroaches, rats, mosquitoes e.t.c
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12. Factors to consider when choosing
a disposal Method
Considerations for selection of a disposal method;
Climatic conditions.
Social cultural perceptions and benefits.
The economic status of the community.
Availability of land.
Potential use of the by-products.
Cost and consequences of method.
Health of the working community.
Quality and quantity of the Solid Waste generated.
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13. WASTE Hierarchy
The waste hierarchy refers to the "3 Rs" reduce, reuse and recycle, which
classify waste management strategies according to their desirability in
terms of waste minimisation
The waste hierarchy remains the cornerstone of most waste minimisation
strategies.
The aim of the waste hierarchy is to extract the maximum practical
benefits from products and to generate the minimum amount of waste
The waste hierarchy is represented as a pyramid because the basic
premise is for policy to take action first and prevent the generation of
waste
The next step of action is to reduce the generation of waste i.e. by re-use,
recycling which would include composting. Following this step is material
recovery and waste-to-energy. Energy can be recovered from processes
i.e. landfill and combustion, at this level of the hierarchy. The final action is
disposal, in landfills or through incineration without energy recovery
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15. Storage of Solid waste
Is the responsibility of those that generate the waste.
Methods involved in storage are dependant on the nature
and quantity of the waste generated, method of collection
and transportation.
Periods of storage needs to be in a dry season wet refuse is
offensive and difficult to handle and good breeding environment
for vectors-flies, rats, mosquitoes e.t.c.
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16. Storage of Solid waste
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Moulded plastic, wheeled waste
bin in Berkshire, England
17. Storage con’t (storage
facilities)MSW
Standard metal dustbins usually galvanized iron or steel: (H2O
tight, rust, fire resistant, and fitted with tight fitting cover).
Plastic sacks/bags/ containers: Generally not recommended for
SW storage because its not environmentally friendly.
Litter bins : Small receptacles used in streets, parks vary btn 5-20L
Skips or metal containers: Usually made from fabricated steel
sheets.
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18. Con’t … storage
Refuse chutes: Used in multiple storied buildings for storage and
collection of solid waste; chute terminates into a specially
constructed closed chamber on the ground floor, which has a
container to receive the waste.
Depots or refuse Bankers: Are usually sited where populations are
dense e.g. markets. Have a durable concrete floor.
Garchey System: A devise from French origin in which waste water
from the kitchen sinks is utilized to propel refuse from flats by
gravitation and flushing (H2O carriage) to the lower levels of the
building.
Garbage Grinder: A provision in the kitchen sink where waste is fed
in to an apparatus containing grinder or cutters that is housed
under the sink
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19. Collection SW
Most problematic phase; due to its cost in terms of labor,
equipment thus more expensive.
Needs trained staff and planned collection routes
Components of refuse collection:
Travel requirements; i.e. from source to disposal sites.
Collection process i.e. transfer from sites to tracks,
travel to disposal sites & delivery at the disposal site
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20. Collection of solid waste
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Waste management in Stockholm, Sweden Waste management in Kathmandu,
Nepal
21. Major focus of SWM disposal
methods
The method selected should be able to;
Reduce the solid wasted generated
Prevent diseases from the waste.
Properly manage and separate hazardous materials.
Possibility of energy generation and recycling.
The disposal mechanism should be in a sanitary manner.
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22. Methods of Disposal of Solid
waste
Decomposition.
Incineration.
Sanitary Land filling / Controlled tipping
Recycling
Burial of the dead
Human Excreta disposal
Energy recovery
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23. Compositing
Involves breakdown of biodegradable waste through natural
processes of decay to produce humus.
Factors to consider before compositing;
Composition of solid waste,
Demand for the composite/salvaged non biodegradable
material,
production of nuisances to neighboring settlements
Public acceptance of use of the sludge/excreta.
Disposal of biodegradable material.
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24. Steps involved in compositing
Separation of materials i.e. bio and non bio-
degradable items.
Shredding or Grinding; Increases the surface area
for bacterial to work.
Blending or proportioning of materials
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25. An active Compost
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An active composit heap.
Recoverable materials that are
organic in nature, such as plant
material, food peeling, and paper
products, can be recovered through
composting and digestion
processes to decompose the organic
matter
26. Incineration
Incineration is a disposal method in which solid organic wastes are
subjected to combustion so as to convert them into residue and gaseous
products
This process reduces the volumes of solid waste with a purpose is to
destroy pathogens.
Best way to reduce the weight and volume of the waste in the shortest
time possible.
Different from open Burning of the waste (done at a small scale and
depends on location and nature of waste).
It requires a careful control of the 3 Ts i.e. time, temperature 750-1000c
and turbulence to achieve complete combustion.
3 progress stages of incineration; Dry stage, combustion stage and burnt
out stage (ash/cinder)
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28. Sanitary Land filling
Landfilling is the primary means of disposal of both residual
municipal solid waste and many hazardous wastes.
Landfilling describes the act of disposing of waste materials to
land by;
◦ Infilling quarries or depressions on the land.
◦ Raising the level of land by landfilling over the land surface.
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29. Con’t Landfills
Choosing a site for a landfill, the following should be considered;
Minimum distance from the city should be 10-15 miles
Site must be structurally sound and free from potential problems
such as landslides and flooding
Should be >200 feet from water source, 500feet from human
habitation.
Projection of amount of waste to be generated aids size of land
required
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30. Con’t …..
Landfill technology is the only available safe
technology for final disposal of waste worldwide
Method of MSW disposal with reduced impact on
PH and sanitation.
Intermediate stages such as incineration are used to
reduce volumes of waste going to landfills to extend
landfill life.
Transfer stations are used to reduce waste
transportation cost to landfills in distant places.
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31. Controlled tipping
Controlled tipping involves pouring of solid wastes in layers,
compacting each layer and then covering it with a layer of inert
material e.g soil.
This is to prevent flies, mosquitoes and rats from breeding and to
avoid smell nuisance, contamination of ground and other water
sources, fire hazards and scavengers.
The solid wastes are dumped in layers not more than 2m deep and
then covered with a layer of earth to a depth of 225mm or 150 mm
Vehicles should move in the direction of the tipping in order to
compact the waste
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32. Works in a landfill
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Landfill Compactor Mpererwe
sanitary Landfill
33. Leachate
The liquid has a high Biochemical Oxygen Demand
(BOD), hence can affect aquatic and plant life.
AIM: Is to reduce leachate production through
diversion of rain wash off.
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34. Leachate Treatment processes
Collection via collection points in the landfill.
Equalization; equalizes the flow thru a constant unit of treatment.
Lagoon can be formed in case of excessive flow. PH neutralization is
done.
Pre-settling: of heavy solids.
Aeration: Add O2 to oxidize metals with production of inert oxide
precipitates. Can also involve biological treatment, sedimentation of
heavy solids and removal of metals by bio-sorption & precipitation.
Clarification; Removal of light suspended solids that give the color to
leachate
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35. Other Disposal Method
Earth burial
Burning or cremation
Some methods practiced but not hygienic
Barging into the sea . Sewing up a corpse in canvas and then
dropping it into the sea with some weight to ensure it sinks. Osama
Bin Laden
Leaving dead bodies in open isolated places to be eaten by
animals and birds of prey like in cultures, Bathing and sleeping with
the dead, e.t.c
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36. Management of Human
Excreta
Human excreta can be both dangerous and useful.
Man produces around 100-200g of fecal matter and
2litres of urine daily.
It contains N2, Phosphorous, Sulphur and other
inorganic compounds &H2O.
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37. Disposal Methods for Human
Excreta
On-site disposal: it remains where it is deposited.
Off site disposal: transported to a treatment plant for
final disposal.
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38. On-site disposal of human
excreta
Pit Latrine.
VIP pit
Pour Flush Toilet
Aqua Privy
Ecological Sanitation Latrine
Ecosan Toilet
Septic Tank
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39. Off site disposal
Waste is transported to distant larger sewage treatment centres
away from the area of generation; e.g. at Bugolobi.
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40. Recycling
Recycling is a resource recovery practice that refers
to the collection and reuse of waste materials such
as empty beverage containers and other materials.
The materials from which the items are made can
be reprocessed into new products.
Material for recycling may be collected separately
from general waste using dedicated bins and
collection vehicles, a procedure called kerbside
collection
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42. Energy recovery
Energy recovery from waste is the conversion of non-recyclable
waste materials into usable heat, electricity, or fuel through a variety
of processes, including combustion, gasification, anaerobic digestion,
and landfill gas recovery.
This process is often called waste-to-Energy
Energy recovery from waste is part of the non-hazardous waste
management hierarchy energy.
Globally, waste-to-energy accounts for 16% of waste management.
Using energy recovery to convert non-recyclable waste materials into
electricity and heat, generates a renewable energy source and can
reduce carbon emissions by offsetting the need for energy from fossil
sources as well as reduce methane generation from landfills.
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44. Benefits of Solid Waste
Management
Waste is not something that should be discarded or disposed of
with no regard for future use.
It can be a valuable resource if addressed correctly, through
policy and practice. With rational and consistent waste
management practices there is an opportunity to reap a range of
benefits. Those benefits include:
Economic: (valuable materials being recovered for reuse and the
potential for new jobs and new business opportunities.)
Social: By reducing adverse impacts on health by proper waste
management practices.
Environmental: can provide improved air and water quality and
help in the reduction of greenhouse emissions.
Inter-generational Equity: generations a more robust economy, a
fairer and more inclusive society and a cleaner environment.
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45. Challenges in SWM
many struggle due to weak institutions, chronic under-
resourcing and rapid urbanization.
Problems with governance also complicate the situation.
Inadequately managed and uncontrolled dumpsites and the
problems are worsening
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46. References:
1. Eawang, Zurbrugg (2003); Solid waste management in
developing countries
2. Waste Management (2013). "Editorial Board/Aims & Scopes".
Waste Management 34: IFC. doi:10.1016/S0956-053X(14)00026-9.
3. Davidson, G. (2011). "Waste Management Practices". Retrieved
from
http://www.dal.ca/content/dam/dalhousie/pdf/sustainability/W
aste%20Management%20Lit
4. https://en.wikipedia.org/wiki/Waste_management#cite_note-6
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47. References
5. Joe et al (2005); Integrated Solid Waste
Management. Extension fact sheet
6. WHO (2006); Solid waste management in
emergencies
7. www.sanicon.net
8. Division Solid Waste Generation and Composition in Kampala Capital City
Authority, Uganda: Trends and Management Nabukeera Madinah, Ali
Boerhannoeddin etal.
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