Solid waste comes from human activities and can be categorized by its origin, contents, and hazard potential. The main sources are residential, industrial, commercial, and construction waste. As waste management developed, open dumping and incineration caused pollution and health issues, leading to the use of sanitary landfills and air pollution controls on incinerators. Waste is further classified as hazardous, non-hazardous, garbage, rubbish, and trash. Municipal solid waste incinerators burn waste continuously and generate heat that can be used to produce steam and electricity through cogeneration, providing an energy recovery option for solid waste management.

1. Solid waste : sources and
management, waste as a
source of energy
By: Likitha hs

2. Introduction
What is solid waste?
Solid waste is the unwanted or useless solid materials generated from human
activities in residential, industrial or commercial areas. It may be categorised in
three ways. According to its:
origin (domestic, industrial, commercial, construction or institutional)
contents (organic material, glass, metal, plastic paper etc)
hazard potential (toxic, non-toxin, flammable, radioactive, infectious etc).

3. Sources of solid waste
● Residential
● Industrial
● Commercial
● Construction and demolition
● Municipal services
● Treatment plants and sites
● Agricultural waste
● Hazardous waste
● Health care solid wastes

4. Developments in waste management
1. Technical approach to solid waste management began in the later part of the
19th century.
2. Construction of first refuse incinerator in England in 1874
3. Development of garbage grinder, compaction trucks and pneumatic collection
system during 1st half of 20th century.
4. By mid-century open dumping and improper incineration were causing
pollution and affecting public health.
5. As result sanitary landfills were developed.

5. ● Land fills were designed and operated in a manner that minimize the risk to
public health and the environment.
● Refuse incinerators were designed to recover heat energy from waste.
● And were provided with extensive air pollution control devices to satisfy
stringent standards of air quantity

6. Waste is mainly classified into:
● Hazardous : waste that causes immediate danger to exposed individuals or
environment
● Non-Hazardous : waste that doesnot cause any immediate effect.

7. Refuse
Refuse include garbage and rubbish
● Garbage - decomposable food waste
● Rubbish - dry materials (glass, paper, cloth, wood )
● Trash - rubbish but includes bulky items (old refrigerator, couches or large
tree stumps

8. ● Construction and demolition waste: it is inhert and non hazardous so it is
disposed in municipal landfills
● Electronic waste: fastest growing, lead, mercury and cadmium are among the
material of concern present in electronic devices.

9. ● Government should focus on residential waste collection
● Waste collection fee should be affordable
● Promote hierarchy of waste management i.e, reduce, reuse, recycle,
recover.
● Encourage waste seperation to maximize flexibility to deal with future charges
Solid waste management common values.

10. Incineration
Furnace operation: Burning is a very effectiv
method of reducing the volume and weight of solid
waste, though it is a source of greenhouse gas
emission.
The waste is burned inside a properly design
furnace.
The combustible portion of the waste combines
with oxygen,releasing mostly Carbon dioxide
water vapour, & heat, leaving an insert residue of
ash, glass, metal and other solid materials called
bottom ash.

11. ● The gaseous by product of incomplete combustion, along with finelly
divided particulate material called fly ash, are carried along in the
incinerator airstream
● In order to remove flyash and gaseoud byproduct befor they are exhausted
into atmosphere, modern incinerators must be equipped with extensive
emission control devices such as fabric baghouse filters.

12. Municipal solid waste incinerators
● MSW incinerators are designed to recieve and burn continuous supply of
refuse.
● A deep refuse storage pit provides enough space for about one day of waste
storage.

13. ● The refuse is lifted from the pit by a crane equipped with a bucket.
● It is then deposited into a hopper and chute above the furnace and released
onto a charging grate.
● The grate shakes and moves the waste through the furnace and allowing air
to circulate around the burning material.
● Furnace are constructed of refractory bricks that can withstand the high
combustion temperatures.
● Then the steam produced with pass into air pollution control system.
● The respective by-product are then converted into fuel, gas and electricity.

14. Energy recovery
● The energy valere of refuse can be as much as one third that of coal,
depending on the paper content & the heart given off during incineration can be
recovered by the use of a refractory lined furnace coupled to a boiler.
● Boilers convert the heat of combustion into steam or hot water, allowing the
energy content of the refuse to be recycled.
● Incinerator that recycle heat energy in this are called waste to energy plants.

15. ● Instead of separate furnace and boiler ,a water-tube wall furnace may also be
used for energy recovery.
● Such a furnace is lined with vertical steel tubes spaced closelybenough to
form continuous sections of walls
● The walls are insulated on the outside in order to reduce heat loss. Water
circulating through the tubes absorbes heat to produce steam, and it also
helps to control combustion temperatures without the nned to excessive air,
thus lowering air pollution control costs.

16. ● Waste-to-energy operate as
■ mass burn system: uses all refuse, without prior treatment or preparation.
■ refuse-derived fuel system: separates combustible waste from non-combustible such as
glass and metal before burning.
● If turbine is installed at the plant, both steam and electricity can be produced
in a process called cogeneration.

17. ● Waste-to-energy systems are more expensive to build and operate than plain
incinerators because of the need of for special equipment & controls, highly
skilled technical personnel, & auxilary fuel systems.
● On the other hand, the sale of generated steam or electricity offsets much of
the extra cost & recovery of heat energy from refuse is a viable solid-waste
management option.

19. Reference
● What a waste: Solid waste Management in Asia: Hoornweg, Daniel with Laura
thomas 1999
● Solid waste as renewable source of energy:current and future possibility in Libya:
By: Tarek A. Hamad.28 sep 2014
● Solid waste management,In solid-waste management: Composition and
properties. Melissa Petruzzello June 30 2020.
● "Waste to Energy: Considerations for Informed Decision-making | International
Environmental Technology Centre". www.unep.org. Retrieved 2022-05-23.
● Publisher: National Academies Press (US), Washington (DC) :National Research
Council (US) Committee on Health Effects of Waste Incineration. Waste
Incineration & Public Health. Washington (DC): National Academies Press (US);
2000. 2, Waste Incineration Overview.

20. Thank you