5CE76

SOLID WASTE MANAGEMENT

Dr.S.Pradeepkumar, M.Tech.,
Ph.D.,
Assistant Professor,
Department of Civil
Engineering ,
VNRVJIET.
Content…
Solid Waste Management:
• Quantity,
• Composition and characteristics of
solid waste,
• Methods of solid waste collection,
conveyance, treatment and disposal.
 In a nutshell “ Solid waste can be
regarded as refuse or waste from any
kind of source”. But any refuse or
waste can be economic resource to
others.
Basic terms related to solid waste
1. Ash : the non-combustible solid by-
products of incineration or other
burning process.
2. Bulky waste: large wastes such as
appliances, furniture, and trees and
branches, that cannot be handled by
normal MSW processing methods.
3. Co-disposal: the disposal of
different types of waste in one area
of a landfill or dump. For instance,
sewage sludges may be disposed of
4. Biodegradable material : any
organic material that can be broken
down by microorganisms into
simpler, more stable com-pounds.
Most organic wastes (e.g., food,
paper) are biodegradable.
5. Compost : the material resulting
from com posting. Compost, also
called humus, is a soil conditioner
and in some instances is used as a
fertilizer.
6. Composting : biological
7.Disposal : the final handling of solid
waste, following collection,
processing, or incineration. Disposal
most often means placement of
wastes in a dump or a landfill.
8.Environmental Impact
Assessment (EIA) : an evaluation
designed to identify and predict the
impact of an action or a project on
the environment and human health
and well-being. Can include risk
assessment as a component, along
9. Environmental risk assessment
(EnRA) : an evaluation of the
interactions of agents, humans, and
ecological resources. Comprised of
human health risk assessment and
ecological risk assessment, typically
evaluating the probabilities and
magnitudes of harm that could come
from environmental contaminants.
10. Garbage : in everyday usage,
refuse in general. Some MSWM
manuals use garbage to mean "food
wastes," although this usage is not
common.

11. Landfilling : the final disposal of

solid waste by placing it in a
controlled fashion in a place intended
to be permanent. The Source Book
uses this term for both controlled
dumps and sanitary landfills.
12. Leachate : liquid that has seeped
through a landfill or a compost pile and
has accumulated bacteria and other
possibly harmful dissolved or suspended
materials.

13. MSW : Municipal Solid Waste.

14. MSWM : Municipal Solid Waste

Management.
15. Putrescible : subject to
decomposition or decay. Usually used
in reference to food wastes and other
organic wastes that decay quickly.

16. Refuse : all kinds of wastes in

solid state excepting excreta from
residential, commercial and industrial
area.
17. Refuse-derived fuel (RDF) : fuel
produced from MSW that has
undergone processing. Processing
can include separation of recyclables
and non-combustible materials,
shredding, size reduction, and
pelletizing.

18. Rubbish : a general term for solid

waste. Sometimes used to exclude
food wastes and ashes.
19. Waste-to-energy (WTE) plant :
a facility that uses solid waste
materials (processed or raw) to
produce energy. WTE plants include
incinerators that produce steam for
district heating or industrial use, or
that generate electricity; they also
include facilities that convert landfill
gas to electricity.
Kinds of Wastes
Solid wastes: domestic, commercial
and industrial wastes especially common
as co-disposal of wastes

Examples: plastics, containers, bottles,

cans, papers, scrap iron, and other
trash
Liquid Wastes: wastes in liquid form

Examples: domestic washings,

chemicals, oils, waste water from
ponds, manufacturing industries
Classification of Wastes according to their Properties

 Bio-degradable
can be degraded (paper, wood, fruits
and others)

 Non-biodegradable
cannot be degraded (plastics, bottles, old
machines,
cans, containers and others)
 Classification of Wastes according to
their Effects on Human Health and the Environment

Hazardous wastes
waste that is reactive, toxic, corrosive,
or otherwise dangerous to living
things and/or the environment. Many
industrial by-products are hazardous.

Non-hazardous
Substances safe to use commercially,
industrially, agriculturally, or economically.
From where these comes???
Solid Waste in India
 7.2 million tonnes of hazardous waste
 One Sq km of additional landfill area
every-year
 Rs 1600 crore for treatment & disposal
of these wastes
 In addition to this industries discharge
about 150 million tonnes of high
volume low hazard waste every year,
which is mostly dumped on open low
lying land areas.

Source: Ministry of Environment & Forest and Climate Change

Growth of Solid Waste In India
 In 1981-91, population of Mumbai
increased from 8.2 million to 12.3
million

 During the same period, municipal solid

waste has grown from 3200 tonnes to
5355 tonnes, an increase of 67%

 Waste collection is very low for all

Indian cities

 City like Bangalore produces 2000

tonnes of waste per annum, the ever
increasing waste has put pressure on
 Estimated waste generation is 1,00,000
MT/day.

 Per capita waste generation ranges

between 0.20 to 0.60 kg.

 Waste collection efficiency in bigger sized

cities ranges from 70 to 90% and in small
sized towns it is up to 50-60%.

 Local authorities spend less 5% of their

budget on waste disposal and maximum
cost is incurred on street sweeping and
collection and transportation of waste.
S.No City Municipal solid Waste (TPD) Per capita waste
(Kg/day)
1. Ahmadabad 1,683 0.585
2. Bangalore 2,000 0.484
3. Bhopal 546 0.514
4. Bombay 5,355 0.436
5. Calcutta 3,692 0.383
6. Coimbatore 350 0.429
7. Delhi 4,000 0.475
8. Hyderabad 1,566 0.382
9. Indore 350 0.321
10 Jaipur 580 0.398
11 Kanpur 1,200 0.640
12 Kochi 347 0.518
13 Lucknow 1,010 0.623
14 Ludhiana 400 0.384
15 Madras 3,124 0.657
16 Madurai 370 0.392
17 Nagpur 443 0.273
18 Patna 330 0.360
19 Pune 700 0.312
20 Surat 900 0.600
21 Vadodara 400 0.389
22 Varanasi 412 0.400
23 Visakhapatnam 300 0.400
 MAJOR DEFICIENCIES
 Littering of garbage due to unorganized
primary collection
 Provision and operation of interim storage
facilities unsatisfactory
 Irregular garbage lifting
 Transportation system not synchronize
with storage facilities
 Processing/ treatment of MSW not
practiced
 Final disposal through dumping and not
SLF
Effects of waste if not managed wisely

 Affects our health

 Affects our socio-economic

conditions

 Affects our coastal and marine

environment

 Affects our climate

Composition of solid waste
 The general composition of solid
waste being generated from the
cities of India is 40% Food & Garden
waste, 5% glass & Ceramics, 3%
Metal, 15% inert, 4% Plastic/ Rubber,
6 % Textile, 27 % Paper.

 Total Organic Fraction - 40%,

Combustible Fraction - 37%,
Recyclables - 8%, Inert - 15%
Source: CPHEEO Manual on MSW, 2005
Characteristics of solid waste
Three types of characteristics:

1. Physical

2. Chemical and

3. Biological
Physical characteristics
 This includes the determination of
percent contents of various
ingredients of the solid waste.
 Bulk Density is generally calculated.
 Function of location, season, storage
time, equipment used, processing
(compaction, shredding, etc.)
 Used in volume calculations.
Chemical characteristics

 Used primarily for combustion and

waste to energy (WTE) calculations
but can also be used to estimate
biological and chemical behaviours.

 Waste consists of combustible (i.e.

paper) and non-combustible
materials (i.e. glass).
Proximate Analysis
 Loss of moisture (temp held at 105 C)
 Volatile Combustible Matter (VCM) (temp
increased to 950 C, closed crucible)
 Fixed Carbon (residue from VCM)
 Ash (temp = 950C, open crucible)
Fusing Point of Ash
 Clinker (agglomerations of carbon and metals)
formation temperature, 2000 to 2200 F
Ultimate Analysis
 Molecular composition (C, H, N, O, P, etc.)
Energy Content
 Determined through lab calculations using
calorimeters
Biological characteristics
Biodegradability
 Organic fraction often equated with the
volatile solids (VS) content of the waste
 However, not all organic materials are easily
degradable
 Biodegradable fraction -
 Degradation produces odours
 Hydrogen sulfide, H2S (rotten eggs)
 Methyl mercaptans
 Aminobutyric acid
 Methane is odourless.
 Attracts flies, vermin, rodents (vectors)
Solid waste collection and transport
Factors considered:
i) Types of Containers:
- Depend on:
- characteristics of SW collected
– E.g. Large storage containers (Domestic
SW: flats/apartment)
– Containers at curbs
– Large containers on a roller
(Commercial/Industrial)
• Collection frequency
• Space available for the placement of
containers
- Residential; refuse bags (7 -10
litres)
- Rubbish bins - 20 -30 litres
- Large mechanical containers - more
commonly used to cut costs (reduce
labor, time , & collection costs)
- must be standardized to suit
collection equipment.
ii) Container Locations:
- side/rear of house
- alleys
- special enclosures
(apartment/condos)
- Basement (apts. in foreign countries)/
newer complexes
iii) Public Health:
- relates to on-time collection to avoid
the spread of diseases by vectors, etc.
iv) Aesthetics:
- must be pleasing to the eye
(containers must be clean, shielded
from public’s view).
v) Collection of SW
- 60-80 percent of total SWM costs.
- Malaysia (other developing nations) -
labor and capital intensive.
- Major problems:
– Poor building layouts - e.g. squatters
– Road congestion - time cost,
leachate, transport costs.
– Physical infrastructure
– Old containers used (leaky/
damaged)
– Absence of systematic methods
(especially at apartments, markets
Collections were made by:

1.Municipal/ District Council

2.Private firm under contract to

municipal

3.Private firm contract with

private residents
 Types of collection
Municipal Collection Services:
a. Residential:
1. Curb (Kerb-side)

2. Alley

3. Set out and set back

4. Backyard collection
Curb (Kerb-side)

 House owner is responsible for placing

solid waste containers at the curb on
scheduled day.
 The work man come, collect and empty
the container and put back at the curb.
 House owner is required to take back the
empty containers from the curb to his
house.
 Quickest/ economical
 Crew: 1 driver + 1 or 2 collectors
 No need to enter property
Set-out, set back
 Collectors have to enter property
 Set out crew carries full containers
from resident storage location to
curb/ alley before collection vehicle
arrives.
 Collection crew load their refuse into
vehicle
 Set-back crew return the container
to storage area.
Alley service

 The containers are placed at the

alley line from where they are picked
up by workmen from refuse vehicles
who deposit back the empty
container.
Backyard service
 The workers with the vehicles carry a
bin, wheel – barrow or sack or cloth
to the yard and empty the solid
waste container in it.

 The bin is taken to solid waste

vehicles where it is emptied.
Commercial-Industrial Collection
Services:

i. Large movable and stationary

containers

ii. Large stationary compactors (to form

bales)
Collection Frequency:
residential areas : everyday/ once in
2 days
communal/ commercial : daily
food waste - max. period should not
exceed :

• the normal time for the

accumulation of waste to fill a
container
• the time for fresh garbage to
putrefy and emit fouls odor
•
Treatment and disposal of solid waste
Several methods are used for
treatment and disposal. These are:
1. Composting
2. Incineration
3. Landfilling
4. Pyrolysis
5. Recycling
Composting
 It is a process in which organic matter of
solid waste is decomposed and converted
to humus and mineral compounds.
 Compost is the end product of composting,
which used as fertilizer.
 Three methods of composting:
(a) composting by trenching
(b) open windrow composting
(c) mechanical composting
Composting by trenching
 Trenches 3 - 12 m long, 2 – 3 m wide and
1- 2 m deep with spacing 2 m.
 Dry wastes are filled up in 15 cm. On top
of each layer 5 cm thick sandwiching layer
of animal dung is sprayed in semi liquid
form.
 Biological action starts in 2- 3 days and
decomposition starts.
 Solid waste stabilize in 4- 6 months and
changed into brown colored odorless
powdery form known as humus.
Open windrow composting
 Large materials like broken glass, stone,
plastic articles are removed.
 Remaining solid wastes is dumped on
ground in form of piles of 0.6 – 1 m height.
 The width and length of piles are kept 1- 2
m and 6 m respectively.
 Moisture content maintained at 60%.
 Temp. increases in side pile.
 After pile for turned for cooling and
aeration to avoid anaerobic
decomposition.
 The complete process may take 4- 6 week.
Mechanical composting
 It requires small area compare to
trenching and open windrow
composting.
 The stabilization of waste takes 3- 6
days.
 The operation involved are
reception of refuse
segregation
shredding
stabilization
Incineration
 Incineration is a waste treatment
process that involves
the combustion of organic substance
s contained in waste materials. 
 Incineration and other high
temperature waste treatment
systems are described as "thermal
treatment".
 Incineration of waste materials
converts the waste into ash, flue gas,
and heat.
Important points regarding incineration

 Supplying of solid waste should be

continuous.

 Waste should be proper mixed with

fuel for complete combustion.

 Temp. should not less than 670 ˚C.

Advantages
 Most hygienic method.
 Complete destruction of pathogens.
 No odor trouble.
 Heat generated may be used for
steam power.
 Clinkers produced may be used for
road construction.
 Less space required.
 Adverse weather condition has no
effect.
Disadvantages
 Large initial expense.
 Care and attention required
otherwise incomplete combustion will
increase air pollution.
 Residues required to be disposed
which require money.
 Large no of vehicles required for
transportation.
Landfilling
 A landfill site is a site for the disposal
of waste materials by burial and is the
oldest form of waste treatment.
 Historically, landfills have been the most
common methods of organized waste
disposal and remain so in many places
around the world.
 The dumping is done with layers of 1- 2 m.
 The layer is covered with soil of 20 cm
thickness.
Advantages
 Simple method.
 No costly plant required.
 No residues or by products need to
be disposed.
 Separation not required.
 Unused land can be used.
 Methane gas can be used ass fuel.
Disadvantages
 Large land required.
 Proper dumping site may not be
available.
 Odor problem.
 Use of insecticides required.
 Leachate should be collected
regularly.
 Methane gas should be collected
properly.
 Green house gas problem.
Pyrolysis
 Heating of the solid waste at very
high temp. in absence of air.
 Carried out at temp. between 500 ˚C
– 1000 ˚C.
 Gas, liquid and chars are the by
products.
Recycling
 Recycling is processing used materials into
new products .
 It reduce the consumption of fresh raw
materials, reduce energy usage, reduce air
pollution (from incineration) and water
pollution (from landfilling).
 Recycling is a key component of modern
waste reduction and is the third
component of the "Reduce, Reuse,
Recycle" waste hierarchy.
 Recyclable materials include many
kinds
of glass, paper, metal, plastic, textile
s, and electronics.
 Although similar in effect,
the composting or other reuse
of biodegradable waste – such
as food or garden waste – is not
typically considered recycling.
 Materials to be recycled are either
brought to a collection centre or
picked up from the curbside, then
Thank u …