Transcript Module 4 Sanitation Systems & Technologies

Sandec Training Tool 1.0 – Module 6
Solid Waste Management
Eawag: Swiss Federal Institute of Aquatic Science and Technology
Solid Waste
Module 6: Chapter
1 Management
Definitions and
Objectives
objectives
Introduction
What is the present
state in SWM?
Review
Non-technical
Aspects such as
Stakeholders and
legal frameworks
Household
hazardous Wastes
and their
characteristics
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
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Definitions & Objectives
What is our focus in this course?
Household
water handling
Sanitation
Waste
generation
Greywater
Excreta,
Faecal sudge
Solid Waste
Processes
Management
Wastewater
Drainage
Stormwater
Sources of
waste
Wastes
Resources
Water supply
Storage – Transport – Treatment – Disposal – Reuse
Planning – Financing – Implementing
Operation & Maintenance – Regulation & Enforcement
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Definitions & Objectives
What is our focus in this course?
 This document gives an overview of the present state in solid waste generation
and -management.
 Characteristics of municipal solid waste and description of available technologies
to treat wastes are presented, as well as non-technical aspects like private sector
involvement and financial arrangements.
Water supply
(Water treatment
& storage)
Solid waste
management
Sanitation (Wastewater & excreta
management)
Stormwater
drainage
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Definitions & Objectives
Definition of municipal solid waste (MSW)
 Waste:
“Unwanted product or material generated by households or industries that has
no value for the one who discards it”
 Municipal solid waste:
All refuse except industrial, construction and debris waste
Indiscriminate dumping
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Definitions & Objectives
What is integrated solid waste management?
Waste
Generators
Storage
systems
Collection & Storage systems
Disposal systems
Households
Heaps
designated disposal
sites
Commercial
Bins
bring system
Health Care
Facility.
Shared
Bins
community container
secondary collection
primary collection
transfer station
indiscriminate disposal
sites
Bags
incineration
Institutions
Shared Bins
and Bags
secondary collection
avoidance / reduction
Industry
recyclables collection/picking/recovering/scavenging
recyclables treatment/processing
recyclables use
SYSTEM PROCESSES
ACTORS and STAKEHOLDERS
PLANNING, MANAGEMENT, OPERATION & MAINTENANCE and MONITORING PROCESSES
SOCIAL, INSTITUTIONAL / LEGAL, ECONOMIC, and ENVIRONMENTAL
FRAMEWORK
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Tool 6
Definitions & Objectives
What are the objectives of integrated solid waste
management?
 Protect environmental health
 Promote the quality of the
urban environment
 Support the efficiency and
productivity of the economy
 Generate employment and
income
(Eawag/Sandec)
3R-Concept: Reduce, Reuse, Recycle
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Module 6: Chapter 2
Definitions and
Objectives
Introduction
What is the present
state in SWM?
Review
Non-technical
Aspects such as
Stakeholders and
legal frameworks
Household
hazardous Wastes
and their
characteristics
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
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Introduction
What are the problems related to insufficient
SWM?
 Inadequate coverage of the population to be served;
 Operational inefficiencies of municipal SW services and management;
 Limited utilisation of the formal and informal sector in recycling activities;
 Public health threats

Formal and informal workers (collectors, sorters) exposed to waste

Garbage piles create reservoirs for insects and rodents that carry
diseases

Open burning of garbage contributes to respiratory illness
 Environmental health threats

Contamination of water, soil, air (metals, toxins, nutrients)

Blockage of water flow in drainages  floods  erosion

Attraction of vultures

Deterioration of aesthetic value of landscapes
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Introduction
What are the categories of MSW and how much
waste is produced?
[kg/capita/yr ]
Eawag/Sandec
MSW generated worldwide (2006):
Approx. 2.02 billion Sandec
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Introduction
How is SWM generation related to urbanisation?
Country
Large cities
Middle cities
Small cities
Nepal
0.5
0.35
0.25
Egypt
1.0 – 1.3
0.5 – 0.8
0.25
0.65 – 0.85
0.45 – 0.65
0.2 – 0.45
Sri Lanka
The urbanisation level of a city indicated by its population size correlates to
waste generation rates. Rural villages and small towns have significantly
lower values of generated waste per capita.
Sandec Training Tool 11
Introduction
What is the present state of SW collection?
Germany
Pakistan
France
United States
China
Colombia
Japan
Switzerland
India
Sri Lanka
Mexico
Ecuador
Philippines
Thailand
Paraguay
Peru
Generated MSW
(kg/capita/yr)
100
400
Argentina
700
(Eawag/Sandec, 2008)
Collection coverage in %
of total MSW generated
25%
50%
75%
100%
About 30 - 50% of the wastes generated in
developing countries are never collected
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Introduction
What is the present state of SW treatment?
Only a tiny fraction of
the collected waste is
treated or properly
disposed of. Most of
the waste is disposed
of in unsanitary
(Eawag/Sandec, 2008)
landfills.
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Introduction
What role does organic waste play in the context
of SWM?
Low-Income
Countries*
Middle- Income
Countries+
High- Income
Countries
Waste generated [kg/cap. & day]
0.4 - 0.6
0.5 - 0.9
0.7 - 1.8
Waste density [kg/m3]
250 - 500
170 - 330
100 - 170
Water content [%]
40 - 80
40 - 60
20 - 30
Organic content [%]
40 - 85
20 - 65
20 - 50
* Countries with GDP < US$ 360 per year per capita; + Countries with GDP > US$ 360, < US$ 3’500 per
year per capita.
(Cointreau, 1982, and BUWAL, 1994, in Zurbrugg, 2003)
The high moisture content of organic wastes influences
the feasibility of collection and treatment options.
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Module 6: Chapter 3
Definitions and
Objectives
Introduction
What is the present
state in SWM?
Review
Non-technical
Aspects such as
Stakeholders and
legal frameworks
Household
hazardous Wastes
and their
characteristics
aspects
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
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Technical Aspects
What are the main technical elements of SWM?
Eawag/Sandec
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Technical Aspects
What are the main options for storage and primary
collection?
(Eawag/Sandec)
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Technical Aspects
Primary storage and transport
Kerbside containers
Muscle-powered cart
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Technical Aspects
Transfer point and secondary collection
(Eawag/Sandec)
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Technical Aspects
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Technical Aspects
Transfer point and secondary collection
“Transfer refers to the movement of waste or materials from the primary collection
vehicle to a secondary, generally larger and more efficient, transport vehicle.”
Transfer point
Compactor truck
Sandec Training
Tool 21 point
Transfer
Technical Aspects
When are compactor trucks feasible?
 Compactor trucks work well where:



there are paved streets wide enough to allow passage
and turning
the waste is set out in containers or bags, so that crews
can pick them up quickly
the density and moisture content of the waste are low
 Non-compactor trucks work well where:






the waste is generally very wet or dense
labor is relatively inexpensive, compared to capital
there is limited access to highly skilled maintenance
collection routes are long and relatively sparsely
populated
controlling capital and operating costs is very important
downtime for maintenance must be minimised.
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Technical Aspects
Problems related to collection
Facts
 Collection uses a large fraction of the total municipal budget
 Municipal systems often service less than 50 % of the population
 The urban poor suffer most from the lack of service
Reasons
 Often illegal settlements
 Urban poor often have limited means of exerting political
pressure
 Often difficult to access with "conventionally used transport
vehicles
 The local authority has great difficulty to expand their services to
a larger area.
Effects
 Waste remains in the neighbourhood, is burnt or flushed by water
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Technical Aspects
What are the major treatment options for organic
waste?
 Composting: Is the main treatment option for
organic wastes.
 Animal feeding represents a higher use of kitchen
wastes than composting, as more of the nutrient
value is productively used.
 Vermicomposting, also called vermiculture or
worm composting, is a relatively cool, aerobic
composting process in which certain varieties of
redworms and earthworms can be used to break
down organic materials.
(Eawag/Sandec)
 Biogasification of organic solid waste is already
widespread in industrialized countries and is
continuously gaining in importance given the
increasing demand for renewable energy as well
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as high market prices for fuel.
Technical Aspects
The two fundamental types of composting
techniques
Windrow composting
 Simple system
 Require little capital
 Require more land
 Process is slower
Windrow composting
Enclosed system composting
 More sophisticated systems
 Require more capital
 Require little land
 Process is faster
Bin composting
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Technical Aspects
Heat treatment
 Composting
produces heat
 Heat sterilises the
compost
(Feachem, 1983)
Heat is one of the most effective ways of killing pathogens
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Technical Aspects
Kitchen waste composting versus animal feeding
Vs.
 Whenever a compost system is being planned, it is
important to evaluate the extent to which compostables are
already being diverted to animal feed. Municipal authorities
are sometimes unaware of these processes!
 If people need their kitchen wastes for animals they are
unlikely to cooperate with centralised composting systems
Sandec Training Tool 27
Technical Aspects
Composting mixed solid waste
 In industrialized countries,
the waste stream is often
too diverse and contains
too many metals and
plastics to allow mixedwaste composting to be
considered a sound
practice.
 In developing countries,
the waste stream contains
high levels of organic
wastes, since the main
non-compostables are not
thrown out or are picked
out prior to final disposal.
However, waste separation at source, i.e. at
the household level, is still preferable.
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Technical Aspects
Vermicomposting
 Vermiculture requires considerable labor and careful
control of composting conditions, including temperature,
moisture, and the mix of ingredients
 It produces a superior fertilizer-type product
 It does not necessarily kill all pathogens
Earthworms
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Technical Aspects
Black soldier flies
 SANDEC is evaluating a new technology which promises to combine
waste treatment with generation of a valuable (by-)product which is in fact
the organism feeding on waste itself, in a simple facility.
 The live cycle of the non-pest Black Soldier Fly, Hermetia illucens fits this
purpose very well.
Adult
4d
4d
Egg
Pupa
~14 d
~14 d
Larva
Prepupa
(Diener, 2008)
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Technical Aspects
Biogasification
 Biogas originates from bacteria in the
process of bio-degradation of organic
material under anaerobic conditions
 Well-functioning biogas systems can yield a
whole range of benefits for their users, the
society and the environment in general
What is Biogas?
 Methane (CH4):
40 - 70 vol.%
 Carbon dioxide (CO2): 30 - 60 vol.%
 Other gases:
1 - 5 vol.%
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Technical Aspects
Advantages of Biogasification
 Production of energy (heat, light, electricity)
 Transformation of organic waste into high quality fertilizer
 Improvement of hygienic conditions through reduction of
pathogens, worm eggs and flies
 Reduction of workload, mainly for women, in firewood
collection and cooking
 Environmental advantages through protection of soil,
water, air and woody vegetation
 Micro-economical benefits through energy and fertilizer
substitution, additional income sources and increasing
yields of animal husbandry and agriculture
 Macro-economical benefits through decentralised energy
generation, import substitution and environmental
protection
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Technical Aspects
Recycling
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Technical Aspects
Recycling
Facts
 Informal recycling is usually well developed.
 Informal does not mean unorganized
 Waste-pickers are mostly driven by poverty, are a social
fringe group and exposed to high health risk
 Recycling further along the waste cycle worsens working
conditions.
 Such activities are often in conflict with formal services if
they are not coordinated
 Recycling is a function of market
Jakarta, Indonesien
 37’000 persons employed
 25% of total waste generated is recycled
 Income: 0.75 - 3.5 US$ / day = 28’000 - 130’000 US$ per day
 Income of city = 1500 US$ /day
 Cost saving for city = 300’000 US$ /month
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Technical Aspects
Importance of Scavengers (Waste pickers)
 In developing countries, informal waste-pickers (known as scavengers) play an
important role in solid waste management systems
 They collect, from the streets, dumpsites, or landfills, re-usable and recyclable
material that can be reincorporated into the economy's production process
 Despite the benefits that they generate to society, waste-pickers are ignored
when waste management policies are formulated.
3.5
3
2.5
Income by recycling in Kolkata (Calcutta)
US$ / day
2
1.5
1
0.5
Scavengers
0
Waste
Pickers
Waste
Buyers
Contract
labourers
Primary
Dealers
Secondary
Dealers
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Technical Aspects
Disposal
Sandec Training Tool 36
Technical Aspects
What options for final disposal exist and how are
they characterized?
 Incineration
 (Sanitary) landfills
(www.consutech.com)
(Encyclopedia Britannica Inc.,1999)
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Technical Aspects
Final disposal
Incineration
 Substantial reduction of the weight (up to 75%) and
volume (up to 90%)
 Electricity/heat production
 Capital intensive (construction and maintenance)
 High-tech level, requiring specialized personnel
 Not suitable for solid wastes with high moisture and low
energy content
 Potential emissions of contaminants
Sandec Training Tool 38
Technical Aspects
Final disposal
Incineration – Energy recovery
Rough estimation of the "lower calorific value (LCV)”
LCV [kcal/kg] = 40(a + b + c + d) + 90e - 46W
in % of wet weight:
a = Paper
b = Textiles
c = Wood & Leaves
d = Foodwaste
e = Plastic & Rubber
W = Water
For incineration without additional fuel a LCV of a least 1'000 kcal/kg is required
In developing countries, LCV is mostly lower than 1000 kcal/Kg!
(4'200 KJ/kg).
For incineration with energy recovery a LCV of a least 1'500 - 1'650 kcal/kg is
required (6'300-7'000 KJ/kg)
Sandec Training Tool 39
Technical Aspects
Final disposal
Landfills
Facts
 Disposal is mostly uncontrolled, unorganized with high
impact to the environment.
 Priority on disposal is lacking (out of sight out of mind)
 If standards are set, they are mostly based on standards
from high-income countries which can not be met and
enforced in the local context
 No acceptance of disposal sites by public
 Rapid urbanization and lacking land use planning makes it
difficult to find new sites in a viable distance
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Technical Aspects
Final disposal
Sanitary landfills
In order to be designated
a sanitary landfill, a
disposal site must meet
the following three general
but basic conditions:
 compaction of the wastes
(Encyclopedia Britannica Inc., 1999)
 daily covering of the wastes (with soil or other material) to remove them
from the influence of the outside environment, and
 control and prevention of negative impacts on the public health and on
the environment (e.g., odours, contaminated water supplies, etc.)
However, meeting all specific aspects may be technologically
and economically impractical in many developing countries
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Technical Aspects
Final disposal
Open dumps
Left unmanaged and uncontrolled, solid
wastes openly dumped on the land:
 generate liquid and gaseous emissions (leachate and
landfill gas) that can pollute the environment, and
 represent a breeding ground for disease-bearing animals
and microorganisms.
Open dump
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Technical Aspects
Non-landfill disposal
 There is a tradition in some countries of disposing of
garbage directly onto farmland.
 Farmers seek the nutrient value of the organic portion of
the waste, as long as there is sufficiently little plastic,
glass, and metal in the MSW.
 This is a hazardous practice, since uncomposted organic
waste contains pathogens.
 Some municipalities dispose of MSW at sea, on land near
the ocean, or on river banks, although many industrialised
and developing countries have banned these practices. In
general, these practices cannot be considered
environmentally sound.
Sandec Training Tool 43
Module: Chapter 4
Definitions and
Objectives
Introduction
What is the present
state in SWM?
Review
Non-technical
Aspects such as
Stakeholders and
legal frameworks
Household
Household
hazardous Wastes
wastes
hazardous
and their
characteristics
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
Sandec Training Tool 44
Household hazardous Wastes
What are household hazardous wastes?
 Households generate small quantities of hazardous wastes
such as oil-based paints, paint thinners, wood
preservatives, pesticides, household cleaners, used motor
oil, antifreeze, and batteries
 Household hazardous waste (HHW) in industrialized
countries such as the US accounts for a total of 0.5% of all
waste generated at home
 In developing countries the percentage is even lower.
Glues, paints, pest control etc.
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Household hazardous Wastes
What are the dangers hazardous wastes can pose?
 Surface Water Contamination
 Groundwater Contamination
 Air Contamination
 Leachate
 Soil Contamination
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Household hazardous Wastes
What are the problems related to E-waste?
 Waste Electrical and Electronic Equipment (WEEE) or E-waste is
one of the fastest growing waste streams in the world.
 In developed countries, it equals 1% of total solid waste on an
average. In developing countries, it ranges from 0.01% to 1% of the
total municipal solid waste generation.
 It contains more than a 1000 different substances,
which fall under “hazardous” and “non-hazardous”
categories.
 Old computers are being dumped in Asia where
they are releasing toxic materials into the
environment.
Sandec
Training
47
Child
sitting
inTool
e-waste
Module 6: Chapter 5
Definitions and
Objectives
Introduction
What is the present
state in SWM?
Review
Non-technical
Non-technical
aspects such
such as
as
Aspects
Stakeholders and
and
Stakeholders
legal frameworks
frameworks
legal
Household
hazardous Wastes
and their
characteristics
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
Sandec Training Tool 48
Non-technical Aspects
Who are the stakeholders to be considered within
the SMW?
 Waste generators
 Central/provincial government
 Municipality
 NGOs & CBOs
 Private formal sector
 Private informal sector
 Internal & external support agencies
SWM can not be solved with innovative technology or
engineering alone. It is an urban issue that is closely related
to a number of issues such as urban lifestyles, resource
consumption patterns, employment and income, and other
socio-economic and cultural issues.
Sandec Training Tool 49
Non-technical Aspects
What are the characteristics of private sector
involvement?
One solution for the problem of costly and vexing provision of MSW
services is to contract service provision with the private sector in the
belief that service efficiency and coverage can be improved, and
environmental protection enhanced.
There are 3 key factors for the success of private sector involvement:
 Competition between different private sector companies, and also, if
possible, between the private and public sectors provides motivation to
maintain effort.
 Accountability: Private sector service providers should sense that they
are accountable to the people whose waste they collect and to the local
government agency that has engaged or licensed them.
 Transparency: Financial dealings and decision-making should be
transparent.
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Non-technical Aspects
How is SMW influenced by legal frameworks and
international treaties?
 Currently, no convention or other measure exists for the comprehensive
management of waste.
 Efforts for dealing with waste on an international scale have been largely confined
to managing the problems associated with the trans-boundary transport of waste.
 Although some technical guidelines for the management of certain specific types
of waste have been drafted under the Basel Convention (1989), the effectiveness
and impact of these guidelines on waste minimization are yet to be determined.
 At the 1992 UN Conference on Environment and Development (UNCED) in Rio de
Janeiro Brazil, the international community adopted the Rio Declaration on
Environment and Development and Agenda 21, an action plan designed to guide
the Earth’s development in a sustainable manner (United Nations Conference on
Environment and Development 1992.
 The same goals were reiterated 10 years later at the World Summit on
Sustainability Development.
 Legal frameworks on country level
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Non-technical Aspects
Financial aspects
 Making cost-effective and informed decisions about municipal solid waste
(MSW) programs requires access to a broad spectrum of information.
Local government officials need to know what solid waste management
really costs. Full cost accounting (FCA) provides a common-sense
approach to:

Identifying and assessing the cost of managing solid waste
operations, and

Aiding decision-makers with short and long-term program planning to
help identify measures for streamlining and improving operations.
 Until recently, in most countries, the management of waste has been
considered to be the responsibility of government, financed by general
revenues (taxes). Other options include:

Polluter pays principle

Privatisation of certain services
Sandec Training Tool 52
Review
Definitions and
Objectives
Introduction
What is the present
state in SWM?
Review
Review
Non-technical
Aspects such as
Stakeholders and
legal frameworks
Household
hazardous Wastes
and their
characteristics
Technical Aspects
for storage,
collection, transport,
treatment and
disposal
Sandec Training Tool 53
Review
Review
 Management of MSW is one of the major challenges worldwide
 Inadequate collection, recycling or treatment and uncontrolled disposal of
waste in dumps lead to severe hazards, such as health risks and
environmental pollution
 The situation is especially serious in low and mid-income countries
 The amount of waste generated is often linked directly to income level and
lifestyle
 The socio-economic, cultural and institutional context in the developing
world requires special consideration of appropriartely adapted
technologies, capacity building, including improvement of skills and knowhow at local government level.
Sandec Training Tool 54
Credits
Credits
Publisher: Eawag, Sandec: Department of Water and Sanitation in
Developing
Countries, P.O. 611, 8600 Dübendorf, Switzerland, Phone +41 (0)44 823
52 86,
Fax +41 (0)44 823 53 99
Editors: Yvonne Vögeli
Concept and Content: Benjamin Hemkendreis and Karin Güdel
Layout: Benjamin Hemkendreis
Copyright: Eawag/Sandec 2008
Eawag/Sandec compiled this material, however much of the text and
figures are not Eawag/Sandec property and can be obtained from the
Internet. The modules of the Sandec Training Tool are not commercial
products and may only be reproduced freely for non-commercial purposes.
The user must always give credit in citations to the original author, source
and copyright holder.
This Powerpoint presentation and its matching lecture notes are available
on the CD of Sandec‘s Training Tool and can be ordered at:
Sandec Training Tool 55
[email protected]