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SOLID WASTE MANAGEMENT
2.1 Introduction
“Solid waste” is the term now used internationally to describe non-liquid waste
materials arising from domestic, trade, commercial, industrial, agriculture and mining
activities and from the public services. Solid waste comprise countless different materials
such as vegetable waste, papers, glass, plastics, wood, yard clippings, food waste, radioactive
wastes and hazardous waste. Solid wastes are all the wastes arising from human and animal
activities that are normally solids, semi-solids, liquids in containers and those are discarded
or useless or unwanted. The term encompasses the heterogeneous accumulation of (Rao,
1991) agricultural, industrial and mineral wastes etc.
Solid waste generation is a continually growing problem at global, regional and local
levels. There has been a significant increase in municipal solid waste generation in India in
the last few decades. The volume of garbage in Indian cities is increasing. Solid wastes create
one of the most visible environmental problems in our country. The management of
municipal solid waste has become an acute problem due to rapid population growth and
economic development in the country (Ramachandra and Shruthi, 2007). In recent, the
quantity of municipal solid waste has been increasing rapidly with growing urbanization and
modern lifestyle and its composition changing (sadeeq et al., 2011). One of the serious and
growing potential problems in larger urban areas is the shortage of land for waste disposal.
Landfill siting is an extremely difficult task to accomplish because the site selection
process depends on different factors and regulations (Yahaya et al., 2010). Environmental
factors are very important because the landfill may affect the surrounding biophysical
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environment (Sardinia, 2007). Effective Solid waste management can be achieved by
controlling the waste generation and taking measures for proper collection, storage,
transportation and disposal of solid waste in an environmental and economic manner. Along
with these, includes legal, financial, administrative and proper planning for waste handling
are the techniques for solid waste management. Integrated solid waste management includes
the application of suitable techniques, better management practices and selection of better
technologies for waste disposal and management (Tchobanoglous and Kreith, 2002).
2.2 Sources and Classification of Solid Waste
Based on the source and type of waste, the classification of municipal solid waste is
described below (Manual on Municipal Solid Waste Management, 2000).
2.2.1 Domestic/Residential Waste
Domestic waste includes the solid wastes that originate during the household
activities such as cleaning, packaging, gardening, cooking and repairs. The waste material
consists of old books, empty containers, old furniture and newspaper.
2.2.2 Municipal Waste
Municipal waste includes the waste materials arising from the domestic, institutional
and commercial activities. The municipal waste comprises of dead animals, dried leaves,
crushed vehicles, market waste, street waste and crushed vehicles.
2.2.3 Commercial Waste
The waste materials included in the category of commercial waste are classified as
garbage, rubbish, organic, inorganic, and hazardous waste and are arisen in departmental
stores, offices, hotels, shops, lodges, restaurants, business centers, warehouses, markets,
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slaughter houses and other commercial establishments. The waste materials comprise of
paper, spoiled and discarded goods and packing material.
2.2.4 Institutional Waste
The waste materials included in the category of institutional waste are those arising
from institutions such as schools, colleges, universities, research institutes, hospitals and
other educational centers. It includes waste materials such as garbage and rubbish in which
some of the waste materials are harmful to human health and the environment.
2.2.5 Garbage
The garbage includes the animal and vegetable waste and the waste is putrescible in
nature. It consists of wastes resulting from the sale, handling, storage, cooking and
consumption of food. It requires immediate removal of waste handling, storage and disposal.
Because the waste produces foul odors and the waste attracts the insects, flies, rats and
rodents.
2.2.6 Rubbish
Rubbish includes the waste materials which are non-putrescible in nature except ash.
It consists of both combustible such as paper, brushes, cardboard and wood, and non-
combustible substances such as cans, glass and scrap metals, etc.
2.2.7 Ash
Ash result from activities such as the burning of dung, wood, coal and other
combustible materials for heating, cooking and other purposes in houses, small industrial
establishments and institutions. When the huge amount of ash produced in factories and
power plants will come under industrial waste.
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2.2.8 Bulky Waste
Bulky waste comprise of tyres, furniture, refrigerators, cookers, vehicle parts, trees,
plastic materials, washing machines, wood etc., arising during the household activities which
cannot be stored in the containers of houses.
2.2.9 Street Waste
Street waste includes the wastes that are collected from parks, streets, walkways and
vacant places. The street waste comprises of plastic, dried leaves, paper, empty cigarette
packs and other empty packets, cardboard and dust. Mostly in developing countries, the
littering of public places is a common problem and in the developing countries manual street
sweeping has seen whereas in developed countries mechanized street sweeping is practiced.
2.2.10 Dead Animals
The dead animals are divided into large animals and small animals that die naturally
or accidentally killed. The large animals are donkeys, cows, sheep and horses which require
immediate removal using special equipment for handling. Small animals are rats, cats, dogs
and rabbits. This category of animals can be disposed by deep burial in special locations.
Otherwise, dead animals attract the flies, insects and causes foul odor and health problems.
2.2.11 Construction and Demolition Waste
These categories of wastes are generated during the activities such as construction,
demolition of commercial buildings, houses and other structures. The construction and
demolition waste materials such as bricks, plumbing materials, concrete, plastics, stones,
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heating systems, roofing materials and electrical wires etc., (MoUD, 2000) are mostly non-
biodegradable substances.
2.2.12 Industrial Waste
The waste materials resulting from the manufacturing processes and other operations
from the industries are included in the industrial waste category. This waste should not be
mixed with the municipal solid waste because the waste materials arising from the industries
may be hazardous and non-hazardous. They must be disposed off following the standards
mentioned under the Hazardous Waste (Management & Handling) Rules, 1989.
2.2.13 Biomedical Waste
The biomedical waste is the waste that is generated during the diagnosis, treatment or
immunization of human beings or animals or in research activities pertaining thereto or in the
production or testing of biological components (BMW Rules, 1998). The biomedical waste
should be disposed by following the Bio Medical Waste (Management & Handling) Rules,
1998. According to the characteristics of waste for their treatment and disposal, biomedical
wastes are classified into ten categories. As per the BMW Rules, 1989, the different
categories of biomedical waste are described in table 2.1
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Table 2.1 Biomedical Waste Types and Treatment Options
Waste Category Type of Waste Treatment and Disposal Method
No.1
Human Anatomical Waste- Human body parts, tissues and
organs.
Incineration/deep burial.
No.2
Animal Waste - Animal body parts, tissues, organs, Bleeding
parts, experimental animals used in research, waste generated
by veterinary colleges, hospitals and animal houses.
Incineration/deep burial.
No.3
Microbiology & Biotechnology Waste - Wastes from
laboratory cultures, human and animal cell cultures and
microorganisms.
Local autoclaving / microwaving
/ incineration.
No.4
Waste Sharps - Needles, syringes, scalpels, blades and glass.
Chemical treatment / autoclaving
/microwaving and mutilation /
shredding.
No.5
Discarded Medicine and Cytotoxic drugs - Contaminated,
discarded and outdated medicines.
Incineration / destruction and
drug disposal in securing
landfills.
No.6
Solid Waste - Blooded cotton, plasters, bandages, dressings,
linens, bedding and other materials contaminated with blood.
Incineration / autoclaving /
microwaving.
No.7 Solid Waste - Catheters, tubing, intravenous sets etc., which
are not included under waste sharps.
Disinfection by autoclaving/
chemical treatment/ shredding/
Microwaving and mutilation.
No.8
Liquid Waste - Waste generated from the washing and
cleaning of laboratories and housekeeping etc.
Chemical treatment and
discharge into drain.
No.9
Incineration Ash - Ash from incineration of any biomedical
waste.
Disposal in engineered landfill.
No.10
Chemical Waste - Chemicals used in disinfections,
production of biological, insecticides etc.
Chemical treatment -Discharge
into drains.
Source: Manual on BMW Rules, 1989.
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2.2.14 Hazardous Waste
Hazardous waste means the wastes generated from the industries or institutes cause
damage to human health and the environment because of their physical, chemical and
biological characteristics. Hazardous waste includes institutional waste, industrial waste and
some of the waste materials from residential, commercial activities cause threat to humanity
and the environment because of their characteristics. Some containers usually mixed with
municipal wastes (IPCC, 2006) such as containers used for paints, solvents and pesticides
and become part of the urban waste stream. This type of hazardous waste causes fire at
landfill sites. The hazardous waste generating from hospitals and the radioactive wastes
requires special handling. The hazardous waste should be disposed separately as per the
Hazardous Waste (Management & Handling) Rules, 1989.
2.3.15 Sewage Waste
The solid by-products of sewage treatment are classified as sewage wastes. The solid
by-products derived from the treatment of organic sludge from both the raw and treated
sewage are mostly organic in nature. At the preliminary stage of sewage treatment, the grit is
separated which is the inorganic fraction of raw sewage. It must be disposed immediately
which may contain pathogens and putrescible organic matter. List of different types and
sources of waste is described in Table 2.2
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Table 2.2: Classification of Solid Wastes
Source: Bhide&Sunderasan, 1987
Types of Solid Waste Description Sources
Food waste
(Garbage)
Wastes from the cooking and consumption of food, market
waste, waste from the handling and storage.
Households, institutions and
commercial such as hotels, stores,
restaurants, markets, etc.
Rubbish Combustible (primary organic) materials include plastics,
paper, rubber, leaves, yard trimmings, grass, wood,
cardboard, boxes, leather and cloth.
Noncombustible materials include glass, ceramics, cans,
stones, metals and other mineral refuse.
Ashes and Residues Residue from burning used for heating and other purposes in
houses
Bulky waste Tyres, furniture, refrigerator, Large auto parts, stoves, trees
and other large appliances.
Street waste Street sweepings, leaves, catch basin dirt, animal droppings,
dust and dead animals.
Sidewalks, streets, alleys, vacant lots,
etc.
Dead animals Large animals such as donkeys, cows, horse etc. Small
animals such as dogs, rats, cats etc.
Construction and
demolition waste
Concrete, stones, plaster, Lumber, wire, roofing and bricks
etc.
Construction and demolition sites,
remodeling and repair
Industrial waste and
sludge
The waste materials resulting from the manufacturing
processes and other operations in the industries such as food
processing wastes. Effluent treatment plant sludge of
industries and sewage treatment plant sludge and grit.
Factories, treatment plants and power
plants etc.
Hazardous wastes Radioactive materials, toxic waste and pathological wastes. Households, industries, stores,
hospitals and institutions.
Horticulture wastes Leaves, Tree-trimmings, waste from gardens and parks. Parks, gardens, trees and public
places.
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2.3 Generation of Solid Waste
Wastes differ in the rate of generating, quantity and quality depending upon the area
of generation. The quantity and quality depend upon the source like residential areas,
industrial areas or commercial areas and also may vary at different times of the year which
will have a marked effect on the selection of method for its collection, processing and
disposal.
Generation of municipal solid waste is related to the demography of the area or city,
due to which urban cities generate huge quantities of waste (Arvind et al., 2011). Among the
four geographical regions of India, the highest amount of solid waste generated by North
India which is 30% of solid waste generated in India i.e., 40,500 tons per day and the least
amount of solid waste generated by Eastern India is 17% of all solid waste generated in India
i.e.23,500 Tons per day.
Among the states in India, Maharashtra,West Bengal, Uttar Pradesh, Tamilnadu and
AndhraPradesh generates the highest amount of solid waste i.e., 22,000 TPD, 15,500 TPD,
13,000 TPD, 12,000 TPD and 11,500 TPD respectively. Among the Indian cities the largest
amount of solid waste (11,520 TPD) is generated from the metropolitan area, Kolkata.
Among union territories, Delhi generates the highest amount of solid waste i.e., 11,500 tons
per day.
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Source: CPHEEO, 2005
Figure 2.1: Share of States and Union Territories in Urban MSW Generated
2.3.1 Urban Wastes
In Andhra Pradesh, 14 cities are generating wastes above 50 tons a day. They are
Hyderabad, Vijayawada, Guntur, Rajahmundry, Visakhapatnam, Kurnool, Nellore,
Nizamabad, Warangal, Anantapur, Eluru, Kakinada, Khammam and Tirupati. The other
cities generate less than 50 tons a day. They are Adoni, Bhimavaram, Chirala, Chittoor,
Cuddapah, Gudivada, Guntakal, Hindupur, Karimnagar, Kothagudem and Machilipatnam
etc.
2.3.2 Per Capita Waste Generation
In India, the per capita waste generation is 0.44 kg/day in 2001 and has increased to
0.5 kg/day in 2011. The amount of waste generation increased by changing of food habits
and life styles. Since 2001 means only in one decade, a 50% increase in the solid waste with
the increase in per capita waste generation by Indian cities. In India the total municipal solid
waste generated is 188, 500 TPD or 68.8 million tons per year and there are 53 cities with
Maharastra
17%
West Bengal
12%
Uttar
Predesh
10%
Tamil Nadu
9% Delhi
9%
Andhra
Predesh
9%
karnataka
6%
Gujarat
5%
Rajastan
4%
Madhya
pradesh
3% Others
16%
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more than million population. In these cities, the per capita waste generation is 500
grams/day and together generate the quantity of municipal solid waste is 86,000 tons per day.
2.3.3 MSW – A Growing Challenge
Over the next two decades, growing urbanization in India will result in a massive
increase of waste. By the year 2021, the urban population is expected to represent 41% of the
overall population. A study conducted by the CPCB on the management of MSW in the
country estimates that waste generation from the present 48 MT per year is expected to
increase to 300 MT per year, by the year 2047 (490 g per capita to 945 g per capita).
2.4. Composition of Municipal Solid Waste in India
Waste composition dictates the waste management strategy to be employed in a
particular location (Oyelola and Babatunde, 2008). Organics in MSW are putrescible and are
food for pests and insects and hence need to be collected and disposed off on a daily basis.
Recyclables represent an immediate monetary value to the collectors. Organics need
controlled biological treatment to be of any value, however due to the general absence of
such facilities, organics do not represent any direct value to informal collectors. The solid
waste composition of the Indian cities was shown in the figure 2.2.
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Source: NEERI, 2005
Fig.2.2: Composition of Municipal Solid Waste in India
2.5 Characteristics of Municipal Solid Waste
For better disposal, planning and management of solid waste, the information on the
characteristics of wastes is necessary (Gonzalez et al., 2010). The physical and chemical
characteristics of municipal solid waste are described as follows:
2.5.1 Physical Properties of Waste
The major physical characteristics of MSW include density, moisture content, particle
size and distribution, field capacity and Permeability of compacted wastes.
2.5.1.1 Density
Density is defined as the mass per unit volume. Knowledge on Density of solid waste
is necessary for proper solid waste management practices such as collection, storage,
transportation and disposal of solid waste mostly for designing sanitary landfill. In landfills,
Plastic 9%
Metals 1%
Paper 8%
Biodegradable
48%
Rags 4%
Glass 1%
Inerts 25%
Others 4%
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the density may vary depending on the total amount of solid waste and daily dumping of the
waste. Density also varies because of the compaction of the wastes, composition and
decomposition of wastes. Density of municipal solid wastes in some Indian cities is given in
table 2.3.
Table 2.3: Density of Municipal Solid Wastes in Some Cities
S.No City Density(Kg/m3)
1 Bangalore 390
2 Baroda 457
3 Delhi 422
4 Hyderabad 369
5 Jaipur 537
6 Jabalpur 395
7 Raipur 405
Source: Bhide&Sunderasan, 1987
2.5.1.2 Moisture Content
Moisture content of solid waste means the weight of the moisture per unit weight of wet
material.
Moisture content (%) = (Wet weight -Dry weight) x100/Wet weight.
A typical range of moisture content is 20-40% and it varies with the season of the year.
Moisture increases the weight of the solid wastes and therefore the cost of collection and
transport increases. Consequently waste should be insulated from rain or other extraneous
water source. Moisture content is a critical determinant in the economic feasibility of waste
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treatment by incineration. During incineration energy must be supplied for evaporation of
water and raising the temperature of the vapor.
2.5.1.3 Particle Size and Distribution
Recovery of waste materials is a key element in solid waste management. For this
purpose, knowledge on the size and distribution of the waste constituents is essential
especially in the utilization of mechanical separators and for waste stream process.
2.5.1.4 Field Capacity
The total amount of moisture content which can be retained in such amount of solid
waste is known as the field capacity of solid waste. There is a significant importance on field
capacity for measuring leachate generation in landfills.
2.5.1.5 Permeability of Compacted Wastes
Among the physical characteristics of solid waste, permeability of compacted waste is
an important character. The movement of liquids, chemicals and gases in a landfill will
depend upon the hydraulic conductivity of the waste. The permeability of the wastes in
leachate generation and in landfill will depend on other physical characteristics such as the
pore size of the solid waste material and surface area. The physical and chemical
characteristics of municipal solid waste were presented in Table 2.4 and Table 2.5
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Table 2.4: Physical Characteristics of Municipal Solid Wastes in Indian Cities
Population
Range (In
Million)
Number
of Cities
Surveyed
Paper Rubber, Leather
And Synthetics
Glass Metals Total
Compostable
matter
Inert
0.1 to 0.5 12 2.91 0.78 0.56 0.33 44.57 43.59
0.5 to1.0 15 2.95 0.73 0.35 0.32 40.04 43.59
1.0 to 2.0 9 4.71 0.71 0.46 0.49 38.95 44.73
2.0 to5.0 3 3.18 0.48 0.48 0.59 56.67 49.07
>5.0 4 6.43 0.28 0.94 0.80 30.84 53.90
Source: NEERI (1995)
2.5.2 Chemical Properties of Waste
The chemical characteristics of the solid waste are described as follows:
2.5.2.1 Proximate Analysis
When the solid waste material is heated to 1050c for one hour, the analysis of loss of
moisture content and analysis of weight of residue after combustion (Amin and Yang, 2012)
will come under proximate analysis.
2.5.2.2 Fusing Point of Ash
During the combustion of the waste materials by fusion, will form a solid resulting the ash.
At which temperature the ash resulting from this process is called as fusing point of ash.
2.5.2.3 Elemental Analysis
This is also known as ultimate analysis. The values of nitrogen, hydrogen, sulfur,
oxygen and carbon of solid wastes can be determined using the elemental analysis. To
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characterize the composition of the waste, the elemental analysis results utilized. Ex: For
biological decomposition process.
2.5.2.4 Essential Nutrients
Nitrogen, phosphorous and potassium are the major nutrients used in the fertilizers.
Knowledge on essential nutrients is required when the organic matter is converted into
fertilizing manure by biological action i.e., for composting.
Table 2.5: Chemical Characteristics of Municipal Solid Wastes in Indian Cities
Population
range (In
Million)
Number
of Cities
surveyed
Moisture
Organic matter
Nitrogen Vs. Total Nitrogen
Phosphorous as P2O3
Potassium as K2O
C/N Ratio
Calorie Value kca/kg
0.1 to 0.5 12 25.81 37.09 0.71 0.63 0.83 30.94 43.59
0.5 to1.0 15 19.52 25.14 0.66 0.56 0.69 21.13 43.59
1.0 to 2.0 9 26.89 26.89 0.64 0.82 0.72 23.68 44.73
2.0 to5.0 3 25.6 25.6 0.56 0.69 0.78 22.45 49.07
>5.0 4 39.07 39.07 0.56 0.52 0.52 30.11 53.90
Source: NEERI (1995)
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2.6 Municipal Solid Waste (MSW) Collection
Citizens deposit the wastes by the roadside from where the Conservancy staff
transfers it to the community bins using a wheelbarrow or other equipment. The location of
the refuse containers should be easily accessible to both the residents and the municipal staff.
The collection is one of the key elements in the solid waste stream which consists of removal
of waste material and transport to the collection point and final disposal (Bhambulkar, 2011).
2.6.1 Types of Collection
Solid waste collection refers to the gathering of solid waste from various sources such
as residential, institutional, commercial and public places. The types of collection systems
are described as follows:
2.6.1.1 Community Bins
The community bins collection system is commonly found in developing countries.
This method is cheaper compared to the other methods. In this method, community bins were
placed in different locations and the numbers of community bins placed are depending on the
total population of that area. The surrounding community members carry and throw the waste
in community bins. In this method one of the most important factor is, the bins should be
covered properly, collected the waste regularly and kept clean always. Otherwise may cause
a public nuisance. Separate bins should be provided for biodegradable and non-
biodegradable waste materials.
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2.6.1.2 Door-to-Door Collection
This is the most convenient method for householders. In this method, the waste
collector collects the waste from each and every house. The household member should keep
the dustbin at the doorstep when the collector arrives and the collector should collect the
waste separately.
2.6.1.3 Block Collection
In this method, for the collection of waste from the households, the collector set time,
day and particular place in the collection vehicle. Households throw that waste in that vehicle
consists of containers for collecting the waste.
2.6.1.4 Curbside Collection
The home owner is responsible for placing the containers to be emptied at the curb on
the collection day and for returning the empty containers to their storage location until the
next collection (Tchobanoglous,1993). The table 2.6 shows the advantages and disadvantages
of the collection system.
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Table 2.6: Advantages and Disadvantages of the Collection System
System Description Advantages Disadvantages
Dumping at
allocated
location
Households and other
generators are required to
dump their waste at a
specified location or in a
built enclosure.
Economical
Loading the waste into trucks is
slow and unhygienic. Waste is
scattered around the collection
point. Adjacent residents and
shopkeepers protest about the odor
and appearance.
Shared container
Households and other
generators put their waste
inside a container which is
emptied or removed.
Low operating
costs
If containers are not maintained
they quickly corrode or damaged.
Adjacent residents complain about
the bad odor and appearance.
Block collection
Collector sounds the
hornor rings bell and wait
at specified locations for
residents to bring waste to
the collection vehicle.
Low operating cost
and less waste on the
streets. No permanent
container or storage
to cause
Complaints.
If all family members are out when
the collector comes, waste must be
left outside for collection. It may
be scattered by wind, animals and
waste pickers.
Curbside
collection
Waste is left outside
property in a container and
picked up by passing
vehicle or Swept up and
collected by the sweeper.
Convenient. No
permanent Public
storage.
Waste that is left out may be
scattered by wind, animals,
children or waste pickers.
If collection service is delayed,
waste may not be collected or some
time, causing considerable
nuisance.
Door to door
collection
Waste collector collects
the waste from each and
every house by knocking
the door or rings.
Most Convenient for
resident. No waste on
streets.
Residents must be available to
handle waste over. Not suitable for
apartment buildings because of the
amount of Walking required.
Yard collection
Collection laborer
enters property to
remove waste.
Very convenient for
Residents. No waste
in street.
The most expensive system,
because of the walking involved.
Cultural beliefs,security
considerations or architectural
styles may prevent laborers from
entering properties.
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2.6.2 Storage Containers
The generated waste is stored within the premises in commercial and industrial areas.
Whereas in residential areas, occupants take it out and transfer to community storage bins.
Plastic cans with lid are preferred for temporary storage in houses though they are subjected
to damage by rats.
Appropriate storage containers are required to save the energy and labor and increase
the speed of collection and reduce the crew size. It is important that the containers should be
functional to the type of materials and the collection vehicles used. Containers should also be
durable, easy to handle, economical as well as resistant to corrosion, weather conditions, and
metals, glass tips etc. Usually these are made up of thick plastics. When the mechanized
collection system is used, the containers are specially designed to fit the truck mounted
loading mechanisms.
2.6.3 Transportation to Disposal Sites
The material collected in community bins is transferred to transport vehicles for
transport to the processing or disposal site. The fleet of transport vehicles should have
sufficient capacity for average and peak loads and should be utilized at optimum levels.
Regular disposal of refuse is essential to maintain proper sanitation.
Transfer refers to the movement of waste or materials from collection points to
disposal sites. Transportation of waste from collection point to disposal sites is carried out by
using different types of vehicles depending on the distances to be covered by them. Larger
vehicles carry the waste from the collection points to the disposal sites. Comparatively small
vehicles discharge waste at transfer stations where the wastes are loaded into larger vehicles
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for transportation to the disposal sites. In metro cities transfer stations are located at different
places to support intermediate transfer of waste from the surrounding areas up to the
dumping grounds.
Transfer stations are centralized facilities where the waste is unloaded from smaller
collection vehicles and re-loaded into larger vehicles (including in some instances barges or
railroads) for transport to a disposal or processing site. The transportation of garbage from
the transfer stations is done generally using trailers and bulk refuse carriers. In large cities,
open flatbed trucks, covered trucks and some compactors are in use, whereas in smaller cities
tractor-trailers, tricycles and animal carts are common (Sharholy et al., 2008). Collection and
transportation of MSW can be schematically shown in Fig 2.3.
Fig 2.3: Schematic Collection and transportation of MSW
Door-to-door collection
Community bins
Collection from Community bins (carried out once in 24 hrs) requires manual &
multiple handling of waste to dump into transportation vehicles.
Transfer Station (TS)
Disposal sites
Disposal sites
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2.7 Segregation of Waste
The municipal solid waste is mixed with a variety of components such as
biodegradable and non-biodegradable substances. If they mixed together, it will be difficult
for safe disposal. Segregation of the solid waste is the key element in the solid waste
management. A variety of waste materials commonly found in the bins are shown in table
2.7.
Table 2.7: Classification for Segregation of Wastes
Source: A Supporting Manual for MSW Rules, 2000, CPCB, Delhi
Biodegradable Wastes Non-Biodegradable Wastes
Organic Waste Recyclable Waste Others (Inorganic
/Hazardous Waste)
Used Tea Leaves/
powder
Rubber Some medicines
Egg Shells Shampoo bottles Paints
Kitchen waste Glass Fluorescent tubes
Fruit peels Wires Spray cans
Meat Metal/ Metal objects Fertilizers,
pesticide
Containers
Bones Plastic Batteries
Flowers Rags Shoe polish
House dust after
cleaning
Leather
Fruit peels Rexine
Garden Waste
Paper (recyclable)
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2.8 Waste Disposal
The waste may come for disposal either directly after its transportation or after
processing. A disposal could be on land or water logged areas for reclamation. The different
functions are interdependent and interrelated which could be better managed by a system
approach.
Disposal is the final stage in the solid waste management and all the wastes whether
they are residential, commercial or from any other sources are collected and transported to a
disposal site. It may be a landfill site or an incinerator or some other mode of disposal. Safe
disposal of solid waste is important for safeguarding the public health, environment and
wildlife as well. Fig.2.4 shows the solid waste disposal methods and the disparity between
countries in waste collection and their disposal were shown in table 2.8. An efficient waste
management system is the one that provides the ecologically sound disposal option for waste
that cannot be reduced, recycled, composted or processed further. A wide range of options is
available for the safe disposal. They are listed as follows:
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Source: MOUD, 2010.
Fig.2.4: Municipal Solid Waste Disposal Methods
2.8.1 Open Dumping
Open dumping is the most common and oldest method for disposal of solid waste in
India, because it is a cheap method (Dhokhikah and Trihadiningrum, 2012) and requires no
planning. Some components of refuse are suitable for open dumping. These include street
sweepings, ashes and incombustible rubbish. However, serious nuisances and hazards will
result if garbage or mixed refuse is disposed of in this manner. They include odours, dust,
wind borne paper, flies, fires, rats and mosquitoes that will breed in rain water held in cans.
Low lying areas which may be brought up to grade by filling are generally chosen for the
dump.
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2.8.2 Composting
Composting is a biological process used for the conversion of bulk organic waste
materials into fertilizing manure, known as compost. The composting process is carried out
by the action of microorganisms present in the soil and waste materials and animal dung is
used for the composting process. Trenches are filled with alternate layers of solid waste and
dung and finally it should be covered with soil to prevent flies and insects and loss of
moisture. To speed up the bacterial action, the solid waste is shredded to about 5cm in size
prior to placement in digesters or bins for decomposition. In the composting process moisture
content is the key element and it should be maintained by 30-40%. In 3 to 4 months, manure
is ready for use. In a good composting process Carbon:Nitrogen ratio is about 30:1 to 40:1.
Several components of mixed municipal solid waste are of no value in the composting
process. Only biodegradable materials will be useful in the composting process.
Advantages
Compost is an excellent organic additive for agricultural soils.
Its principal value when applied to the soil is acting as a good soil conditioner.
It lightens the soil, promotes aeration and helps to retain moisture by adding humus.
It has some fertilizing value. It contains about 1.5% N, 1% P2O5, 0.8% K20, 30%C
and 40% ash.
Compost itself presents no health hazards, as the heat developed during composting
kills the pathogens and eggs of parasites.
Completely composted material is not attractive to flies.
It may reduce the volume of total waste for disposal.
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Composting process may become more popular in the future if farmers recognize its
benefits and values which are safer than the chemical fertilizer.
It contains several micronutrients needed by plant life.
It increases the permeability of the soil due to its porous nature.
The soil drainage will also improve, thereby reducing the possibility of water logging.
It enriches land fertility.
2.8.3 Vermi Composting
Vermicomposting is the process by which worms are used to convert organic
materials (usually wastes) into a humus-like material known as vermi compost.
Vermicompost is the end product of the breakdown of organic matter by some species of
earthworm (Anjaneyulu, 2004). Vermicompost is a natural fertilizer, nutrient- rich contains
nitrates, phosphates, potassium and is a good soil conditioner. As a processing system, the
vermicomposting of organic waste is very simple.
Benefits
It is very rich organic manure.
It does not contain any chemicals harmful to the plants or man.
If done efficiently it is very cost effective.
It is ecofriendly and helps us in converting waste to wealth.
Carefully prepared vermicompost increases the production of certain crops from 30-
60%.
Provide micro and macro nutrients to the plants.
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Reduces the use of chemical pesticides.
Improves the quality of crop production.
2.8.4 Ocean Dumping
The disposal of refuse by dumping into sea is possible only in case of coastal cities.
While dumping the refuse, care is taken to take the refuse in barges, sufficient distance away,
2 to 3 km from the beach and dumped there. The refuse may be washed ashore under tidal
conditions. This method is very costly and is not used in India.
2.8.5 Pyrolysis
Pyrolysis is also referred to as destructive distillation or carbonisation. It is the
thermal decomposition of organic matter at high temperature (900°C) in an inert (oxygen
deficient) atmosphere or vacuum, producing a pyroligenous liquid having high heat value
and is a feasible substitute of industrial fuel oil.
2.8.6 Gasification
Gasification involves thermal decomposition of organic matter at high temperatures
in the presence of limited amounts of air/oxygen, producing mainly a mixture of combustible
and non-combustible gas (carbon monoxide, hydrogen and carbon dioxide). This process is
similar to Pyrolysis, involving some secondary/different high temperatures (> 1000°C) which
improve the heating value of gaseous output and increases the gaseous yield (mainly
combustible gases, CO+H2) and lesser quantity of other residues.
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2.8.7 Incineration
Incineration is a waste treatment process that involves the combustion of organic
substances contained in waste materials. Incineration of waste materials converts the waste
into ash, fuel gas and heat.
The incineration of MSW essentially involves combustion of waste leading to
volume reduction and recovery of heat to produce steam that in turn produces power through
steam turbines. Basically, it is a furnace for burning waste and converts MSW into ash,
gaseous and particulate emissions and heat energy. The efficiency of the technology is linked
to the waste characteristics and their properties such as moisture content and calorific values.
It requires high temperature of 8000-1000
0c and sufficient air and mixing of gas steam. The
combustion residues include bottom ash, fly ash and non-combusted organic and inorganic
materials. Modern incinerators include pollution mitigation equipment such as fuel gas
cleaning. There are various types of incinerator plant design: moving grate, fixed grate,
rotary-kiln and fluidized bed. The typical incineration plant for MSW is a moving grate
incinerator. The advantages and disadvantages of incineration of solid wastes are as follows:
Advantages
One of the most attractive features of the incineration process is that it can be used to
reduce the original volume of combustibles by 80 to 95 percent (MSW Incineration,
Decision Maker’s Guide, 2000).
The output (ash) is considerably more inert (stable) than incinerator input, mainly due
to the oxidation of the organic component of the waste stream.
Energy from waste can be recovered.
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The waste is sanitized.
The main advantage of incineration over all other methods is the volume reduction of
waste.
Disadvantages
Large initial capital is required.
Qualified technicians are required and they are not always available.
Its operation and maintenance is complex.
Operational costs are beyond the capabilities of the communities.
It is not flexible enough to treat additional quantities.
At times auxiliary fuel is required when the calorific value of the refuse is low and
contains high humidity.
Control equipment is needed to avoid air pollution since no incinerator produces
emissions completely free of pollution.
2.8.8 Sanitary Landfill
Sanitary landfill differs from ordinary dumping in that the material is placed in a
trench or other prepared area, adequately compacted and finally covered with soil at the end
of the working day. The term modified sanitary landfill has been applied to those operations
where compaction and covering are accomplished once or twice a week (Thomas et al.,
1968). Such a landfill is a well-controlled and truly sanitary method of disposal of solid
wastes upon land. It consists of four basic operations:
The solid wastes are deposited in a controlled manner in a prepared portion of the site.
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The solid wastes are spread and compacted in thin layers.
The solid wastes are covered daily or more frequently, if necessary, with a layer of
earth.
The cover material is compacted daily. The final result can be a golf course or play
field.
Advantages
The initial capital investment is lower than that required to implement either
incineration or composting methods.
Low cost of operation and maintenance.
It is a complete and final method that can receive all types of municipal solid wastes,
eliminating the problem of ashes from incineration and materials that do not degrade
during composting.
In large sanitary landfills that receive more than 200 tons of refuse per day, methane
gas may be recovered and used as an alternative source of energy.
It can be located near an urban area if there is available land. The costs of
transportation are then reduced and the landfill can be better supervised.
It reclaims lands that can be used for the construction of parks, recreational areas, or
sports fields.
A stationary landfill can begin to operate in a short time.
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Disadvantages
The acquisition of land is the first barrier to construct a sanitary landfill as opposition
from the public may be strong due to lack of knowledge of the sanitary landfill
technique.
Rapid urbanization has increased land cost. This means that a sanitary landfill has to
be located in collection route, raising the cost of transportation.
Construction must constantly be supervised to maintain a high level of quality. In
small communities, the cleaning service should make the daily supervision but should
have the advice of a knowledgeable professional with experience to oversee the
progress of the work from time to time.
The landfill may become an open dump if municipal administrators are reluctant to
invest in operation and maintenance.
Contamination of nearby surface and groundwater may occur if proper precautions
and not taken.
The most significant settlement occurs in the first two years after the landfill is
completed, making the use of the land difficult. Settlement time will depend upon the
death of the landfill, type of solid waste, degree of compaction and the amount of
rainfall in the area.
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Table 2.8: Disparity between Countries in Waste Collection and their Disposal
Source: Cointreau (2008)
2.9 Environmental and Health Impacts of Solid Waste
Improper disposal of solid waste contaminates the natural resources like air, water
and land and deteriorates the quality of life and human health. Improper solid waste
management shows the impact on the planet earth and result in global warming and climate
changes. Surface water resources and ground water resources contaminate due to the
indiscriminate and improper disposal of solid waste and generation of leachate from the
landfills (Rajput et al., 2009). From these landfills, the solid waste generates methane which
is a greenhouse gas and has 21 times more global warming potential than the carbon dioxide.
Municipal solid waste can attract the insects, flies, rodents and spread diseases such as
dengue, malaria and plague.
Waste collection Proper disposal
Low -income countries 40 % 5 %
Middle-income countries 60 % 30 %
High-income countries 100 %
100 %
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Impacts caused by improper solid waste management are listed below:
Rag pickers working at waste disposal site are vulnerable to many diseases like lung
infections, skin problems etc.
The burning of the solid waste at the disposal site causes air pollution and
consequently spread the diseases and deteriorates health condition of surrounding
people.
Methane is one of the greenhouse gases and is the main ingredient of landfill gas,
leading to climate change and the methane gas has more potential than the carbon
dioxide as a greenhouse gas.
The improper disposal of solid waste can cause foul odor and cause aesthetic
nuisance.
The chemical reaction between the pathological, toxic and municipal solid waste
components can have serious effects on public health and the environment.
The polluted water from waste disposal sites can contaminate the water resources like
lakes and ponds. If these water resources contain chemicals they mix-up with the
water bodies and cause health problems.
If the collection vehicles are not covered and designed properly, during the
transportation leads to foul odor and can cause damage to the surface of the roads.
Plastic bags are non-biodegradable substances and cause an aesthetic nuisance
(Dhayagode et al., 2011).
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Some health care items and dangerous items such as explosive containers, broken
glass, hypodermic needles, blades, and blooded cotton may pose risks of injury to
people who sort through the waste.
If there are no proper collection systems, waste collection workers may face different
types of problems.
While manual handling the waste, the workers have to take protective measures
otherwise diseases may attack due to direct contact of pathogens.
If the solid waste is not collected regularly, it may deteriorate the urban environment
and cause unhygienic conditions.
From uncollected and decomposing wastes, dust particles and Aerosols can spread
(Thirumala et al., 2012) fungi and other disease causing agents.
The open burning and open dumping of municipal solid waste causes air pollution.
During the open burning of the solid wastes some of the products may enter the
environment which is hazardous.
Solid waste is the best food for flies and the breeding of flies spread so many
diseases.
Uncollected wastes mixing in drains, causing flooding and unsanitary conditions.
If the community bins are not covered, they may attract stray dogs, which has been a
major cause of the spread of rabies.
Open waste bins also attract stray and domestic cattle and causes nuisance.
Mosquitoes breed in blocked drains and in rainwater that is retained in discarded
cans, tire and other objects. Mosquitoes spread disease, including malaria and dengue.
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Rats find shelter and food in waste dumps. Rats consume and spoil food, spread
disease, damage electrical cables and other materials and inflict unpleasant bites.
Garbage dumps contribute to the seepage of toxic chemicals to ground water and such
contaminations have been linked up with increases in cancer incidences.
2.10. Waste Management Practices
The better waste management practices are described below and fig. 2.5 shows the
most favored and least favored options for waste management.
2.10.1 Waste Prevention
Waste prevention is defined as preventing the generation of waste at the source level
only and encouraging the methods reuse, recycling and recovery. Solid waste generation is
increasing with the change in lifestyles and the high amount of solid waste and improper
solid waste management creates a threat to the environment. Best practices are most
necessary and essential for better solid waste management. To achieve this, best practice is to
be followed 3 Rs principle. 3 Rs principle includes the most preferred options i.e. waste
reduction, reuse and recycling for management of solid waste (NSWAI, 2008). For the
prevention of solid waste generation, the most effective methods are the waste reduction and
reuse.
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Fig.2.5: Waste Management Practices
2.10.2 Reduce
Source reduction often also called the waste minimization means less production and
less consumption of products or materials. Waste generation may be reduced due to changes
in the design, purchase and manufacturing process of products.
2.10.3 Reuse
Reuse is closely related to source reduction. Reuse is the next step to the source
reduction and reduce is one of the steps of reuse. Reuse means usage of products again and
again. By following the method reuse, the amount of waste generation decreases after the
consumption and at the same time it reduces the manufacturing of products and finally
reduces the amount of solid waste generation at the source level only.
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Many ways to reuse the materials include using rechargeable batteries, refillable pens
and donating any unwanted products etc. Reuse is the best method than the recycling. In
another way reuse some materials such as metal, glass, energy from the waste materials by
the extraction of useful raw materials. These are the Simple and best ways to reuse the
products.
Domestic reuse is the best example. Where water scarcity is acute, the treated
wastewater and reuse it for domestic purposes. Treated sewage can also be conveniently used
for boating, fishing, gardening and other recreational purposes.
2.10.4 Recycle
Recycling means the converting of waste materials into useful forms. Recycling is
often voiced as the antidote to the solid waste problem. Hence recycling of wastes can only
be a supplement to the most effective method of reducing solid waste generation to the
maximum possible extent. This has become necessary today due to the following reasons:
Resources of nature are fast depleting due to rising populations and increasing
consumption rates. Resource depletion becomes a serious problem unless resources
are also generated from waste materials.
Waste products are accumulating in the environment demanding space, health hazards
and causing nuisance.
Economic gains motivate recycling to some extent.
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For reducing the quantity of solid waste generation, recycling is another best
technique. Recycling means the reusing materials and objects in their original or changed
forms rather than discarding them as wastes (Wyld, 2010).
2.10.5 Importance and Benefits of Recycling and Reuse
For an integrated solid waste management, “Recycle” and “Reuse” are the key
elements. Recycling and reusing materials not only reduces the amount of materials into the
solid waste stream also reduces the costs for processing of the collection, transportation and
disposal etc. The importance and benefits of recycling and reusing are listed as follows:
By utilizing energy from the waste materials, natural resources should be conserved.
Minimize the impacts on the environment and human health by reducing the amount
of waste generated.
The use of recycled materials reduces the pollution and energy consumption.
Affordable market prices for recycled materials.
Helps to establish industries of secondary materials.
Generate income to the society because of the market value of waste materials.
Reduces the amount of waste that has to be imported, by producing secondary raw
materials.
Economic development from industrial establishments, levy collection and
employment generation.
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2.11 The Stakeholders Involved in the Management of MSWM in INDIA are
The Ministry of Environment and Forests: The Ministry of Environment and
Forests is responsible for general aspects related to waste management, and draws up,
coordinates the environmental policy and overseas the implementation of the federal
legislation regarding waste management.
The Central Pollution Control Board: Coordinate the activities of the State
Pollution Control Boards and provide technical assistance and training to the
personnel. Disseminate information sponsor research relating to waste management.
To perform functions prescribed by the Government.
The State Pollution Control Board: Plans a comprehensive program for the
prevention, control or abatement of air pollution and water pollution. To inspect, at all
reasonable times, any control equipment or process. Prior to installation of a landfill
or incinerator, permission from SPCB must be obtained.
City Corporation: City Corporation issues permits and creates policy for waste
management. Provides waste management services or operates disposal, recycling or
composting facilities. Often contracts out services to the private sector.
Private Formal Sector: Participates in performing the functions of collection and
transportation of the waste and may operate disposal, transfer and recycling facilities.
Private Informal Sector: Participates in collection of the recyclable waste, transfer
to the recycling facility and recycling of waste.
Service Users: People who use the service of municipal waste management.