SOLID WASTE MANAGEMENT, CLASSIFICATION OF SOLID WASTE, METHODS FOR THE TREATMENT, TYPES OF COMPOSTING

1. SOLID WASTE SOURCES AND
MANAGEMENT
COMPOSTING
PRESENTATION BY
S.R. BHARATHKUMAAR,
I M.SC BIOTECHNOLOGY 2019-2021
BHARATHIAR UNIVERSITY.
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2. INTRODUCTION
WASTE:
Depending on the physical state they are classified as
 Solid waste
 Liquid waste
 Gaseous waste
SOLID WASTE:
Solid waste is the unwanted or useless solid materials generated
from combined residential, industrial and commercial activities in a given area.
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3. SOLID WASTE
MANAGEMENT:
It is the process of
collection , transportation
and disposal of solid waste
in a systematic, economic
and hygienic manner
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4. CLASSIFICATION OF SOLID WASTE
Sources of origin
Residential wastes
Commercial wastes
Institutional waste
Municipal wastes
Physical nature
 Garbage
 Ashes
 Combustible and non-combustible wastes
 Demolition and construction waste
 Hazardous wastes
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5. S.N
O
TYPE DESCRIPTION SOURCES
1. Garbage
(Biodegradable
food waste)
Residual vegetable or animal
wastes or food wastes. They are
putrescible, decompose rapidly,
especially in warm weather.
Houses, hotels,
dairies, meat,
stalls et,.
2. Combustible
and non-
combustible
solid waste
• Paper, card board, plastics,
textile, rubber, leather, wood,
furniture, garden trimmings are
combustible .
• Glass, crockery, tin cans, ferrous
and non ferrous metals are non-
combustible
Houses, hotels,
markets etc..
3. Ashes Residues remaining after the
burning of wood, coal, coke, and
other combustible waste
Different type of
industries, thermal
power plants etc.
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6. S.NO TYPE DESCRIPTION SOURCES
4. Demolition
and
construction
wastes
Inert wastes such as dirt,
stones, concrete, bricks,
pieces of plumbing and
heating and electrical parts
Demolition and
construction of
buildings
5. Industrial
wastes
They are specific for a
specific industry. Their
characteristics very widely as
inert highly biodegradable,
toxic, reactive, odorous,
corrosive, hot, cold, coloured,
viscous, inflammable and
dusty
Different types
of industries,
thermal power
plants, hospitals
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7. METHODS FOR THE TREATMENT
Open dumps
Landfills
Anaerobic digestion
Composting
Vermicomposting
Encapsulation
Incineration
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8. 1. OPEN DUMPS
Refer to uncovered areas that are used to dump solid waste of all
kinds
Waste is untreated and not segregated
It is the breeding ground for flies, rats and other insects that
spread disease
Rain water run-off from these dumps contaminates nearby land
and water, thereby spreading disease.
In some countries open dumps are being phased out
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9. 2. LANDFILLS
 A land fill may also refer to the ground that has been filled in with
soil and rocks instead of waste materials, so that it can be used for
a specific purpose, such as for building houses.
 Landfill, also known as dump or tip is a site for disposal of waste
materials by burial.
 Sanitary landfills are designed
to greatly reduce or eliminate the
risks that waste disposal may
pose to the public health and
environmental quality
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10. 3. COMPOSTING
• Composting is the biological decomposition of organic waste
under controllable aerobic condition
• Industries as paper, agricultural and food processing give out
wastes which are almost 100% organic. The organic matter can be
composed to yield good manure
• Compost is the end product obtained after subjecting the organic
fraction of solid waste to aerobic or anaerobic decomposition to
yield humans like solid, carbon-dioxide, water vapour and energy
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11. MECHANISM OF COMPOSTING:
• Very complex process involving the participation of several
microorganisms like bacteria, fungi and actinomycetes
• The bacteria bring out the decomposition of macro molecule
namely proteins and lipids. Besides generating energy(heat),
Fungi and actinomycetes degrade cellulose and other complex
organic compounds.
Dividing into three stages with reference of changes in temperature
• Mesophilic stage
• Thermophilic stage
• Cooling stage
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12. FACTORS INVOLVED
IN COMPOSTING
 Feed stock and
Nutrient balance
 Particle size
 Moisture content
 Oxygen flow
 Temperature
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13. FEEDSTOCK AND NUTRIENT BALANCE
• Composting or controlled decomposition, requires a proper
balance of “green” organic materials and “brown” organic
materials
• Green organic materials- Grass clippings, food scraps and manure
which contain large amount of nitrogen
• Brown organic materials- Dry leaves, wood chips and branches
which contain large amounts of carbon but little nitrogen
• Obtaining the right nutrient mix requires experimentation and
patience. It is part of the art and science of composting.
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14. MATERIAL C:N RATIO
Vegetable waste 12-20:1
Alfalfa hay 13:1
Cow manure 20:1
leaves 40-80: 1
Corn stalks 60:1
Oat straw 74:1
Apple pomance 21:1
Wheat straw 80:1
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15. PARTICLE SIZE
• Grinding, chipping and shredding materials increases the surface
area on which micro organisms can feed
• Smaller particles also produce a more homogenous compost
mixture and improve pile insulation to help maintain optimum
temperatures
• If the particle are too small, however they might prevent air from
flowing freely through the pile.
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16. MOISTURE CONTENT
• Micro-organisms living in a component pile need enough
moisture to survive.
• Water is the key element that helps transports substances within
the compost pile and makes the nutrients in organic material
accessible to the microbes.
• Organic material contains some moisture in varying amounts, but
moisture also might come in the form of rainfall or intentional
watering.
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17. OXYGEN FLOW
• Turning the pile, placing the pile on a series of pipes or including
bulking agents such as wood chips and shredded newspaper all
help aerate the pile
• Aerating the pile allows decomposition to occur at a faster rate
than anaerobic conditions.
• Care must be taken, however not to provide too much oxygen,
which can dry out the pile and impede the composting process.
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18. TEMPERATURE
• Microorganisms require a certain temperature range for optimal activity.
• Certain temperatures promote rapid composting and destroy pathogens and
weed seeds.
• Microbial activity can raise the temperature of the pile′s core to at 140⁰F
• If the temperature doesn’t increase, anaerobic conditions (i.e., rotting) occur.
• Controlling the previous four factors can bring about the proper temperature.
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19. CRITERIA FOR COMPOSTING:
• C:N ratio- 25-35 :1
• Particle size – 50mm
• Moisture content – 50-60%
• Air flow – 0.6 – 1.8m3 /day/ kg
• Temperature - 55⁰C- 60 ⁰C, for 1st 3 days
• Agitation – Periodic turning at 15 days interval
• Heap size – any length, 1.5m high, 2.5m wide
• Activators – Microbial organisms
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20. TYPES OF COMPOSTING
• Onsite composting
• Vermicomposting
• Aerated (turned) window composting
• Aerated static pile composting
• In- vessel composting
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21. ONSITE COMPOSITING
• Organizations that are going to compost small amounts of wasted
food can compost onsite.
• Composting can significantly reduce the amount of wasted food
that is thrown away
• Yard trimmings and small
quantities of food scraps can
be composed onsite.
• Animal products and large
quantities of food scraps are
appropriate for onsite
composting.
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22. PROCEDURE
Start with a 4 to 6 inch layer of coarse material set on the bottom
of the composter or on top of the soil.
Add a 3 to 4 inch layer of low carbon material
Add a 4 to 6 inch layer of high carbon material
Add a 1 inch layer of garden soil or finished compost
Mix the layers of high carbon material, low carbon material and
soil or compost
Repeat steps 2 through 5 until the composting bin is filled
(maximum 4 feet in feet in height). Cap with dry material.
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23. IN-VESSEL COMPOSTING
• In-vessel composting can process large amounts of waste without
taking up as much space as the windrow method and it can
accommodate virtually any type of organic waste( e.g., meat,
animal manure, bio-solids, food scraps)
• This method involves feeding organic materials into a drum, silo,
concrete-lined trench or similar equipment
• This allows good control of the environmental conditions such as
temperature, moisture, and airflow.
• It is mechanically turned or mixed to make sure the material is
aerated. The size of the vessel can vary in size & capacity.
• It takes a few more weeks or months until it is ready to use
because the microbial activity needs to balance and the pile needs
to cool. 23

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25. AERATED (TURNED) WINDROW COMPOSTING
• Aerated or turned windrow is suited for large volumes such as
that generated by entire communites and controlled by local
governments and high volume food- processing buisness (eg.,
resturants, cafeterias, packing plants)
• This type of composting involves forming organic waste into
rows of long piles called Windrows and aerating them
periodically by either manually or mechanically turnig the piles.
• The Ideal pile height is between four and eight feet with a width
of 14 to 16 feet. This size pile is large enough to allow oxygen
flow to the windrows core.
• Large volumes of diverse wastes such as yard trimmings, grease,
liquids and animal byproducts (such as fish and poultry wastes)
can be composed through this method
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27. AERATED STATIC PILE COMPOSTING
• Aerated static pile composting produces compost relatively
quickly (within three to six months)
• It is suitable for relatively homogenous mix of organic waste
and work well for larger quantity generators of yard trimmings
and compostable municipal solid waste.
• In aerated static pile composting organic waste mixed in a large
pile. To aerate the pile layers of loosely pled bulking agents (g.,
wood chips, shredded newspaper ) are added so that air can pass
from the bottom to the top of the pile.
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29. 4. ANAEROBIC DIGESTION
• It is a regulated version of the natural events of landfill, in that
it results in the controlled release of methane rich bio-gas,
which offers the potential for a very form of energy from waste
• It is carried out in large fermented tanks
• In these tanks, solid waste is taken in the absence of oxygen and
the anaerobic bacteria convert the large organic molecules
mainly methane and carbon dioxide
• Unlike composting, Anaerobic digestion occurs at three different
temperatures namely;
• Cryophilic (<20°C)
• Hemophilic (20-45°C)
• Thermophilic (>45°C)
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30. MICRO-ORGANISMS INVOLVED IN ANAEROBIC
DIGESTION
Hydrolytic fermentative bacteria – Clostridium and Peptococcus
Acetogenic bacteria – Syntrophobacter and Syntrophomonas.
Acidogenic bacteria- Methanothrix and Methanosarcina
Methanogenic bacteria- Methanobacterium and
Methanobrevibacterium
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31. 5. 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, flue
gas and heat
The ash is mostly formed by the inorganic constituents of the
waste and may take the form of solid lumps or particulates carried
by the flue gas.
The flue gas must be cleaned of gaseous and particulate pollutants
before they are dispersed into the atmosphere
Heat generated by incineration can be used to generate electric
power
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32. TYPES OF
INCINERATORS
Multiple
chamber
incinerators
Municipal
incinerators
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33. MULTIPLE CHAMBER INCINERATORS
It is an incinerator with two or more refractory lined combustion
chambers in series separated physically by refractory walls,
inter-connected by a gas passage.
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34. USE AND BY PRODUCT OF INCINERATION
 After the incineration process the left out product can be used as
aggregate for low grade concrete
 Also use as road metal
 Ash is used for making bricks or block manufacturing
 Stream used for electricity generation by running turbine
 Also used as filler material
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35. PRODUCT INCINERATION WITH THEIR USE
HEAT
 Heat is used for generating steam which is used for electricity
generation by running turbine
FURANS AND DIOXINS
 It is the most biggest concern for environmentalists
 These are injurious to health
CARBON DIOXIDE
 CO2 Plays a vital role in global warming, as this is green house
gases
 Generally it is seen that everything which has carbon in its
composition is when processed by incineration evolves out as
CO2
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36. WASTE
MANAGEMENT
CONCEPT
•REUSE
•REDUCE
•RECYCLE
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