Disposal of waste

1. DISPOSAL OF
WASTE
MRS. NAMITA BATRA GUIN
Associate Professor
Deptt. of Community Health
Nursing

2. SOLID WASTE DISPOSAL

3. • The term "solid wastes" includes garbage (food wastes)
rubbish (paper, plastics, wood, metal, throw-away
containers, glass), demolition products (bricks, masonry,
pipes), sewage treatment residue {sludge and solids from
the coarse screening of domestic sewage), dead
animals, manure and other discarded material. It should
not contain nightsoil.

4. SOLID WASTE IS A HEALTH HAZARD
• It decomposes and favours fly breeding
• It attracts rodents and vermin
• The pathogens which may be present in the solid
• Waste may be conveyed back to man's food through flies and dust.
• There is a possibility of water and soil pollution, and
• Heaps of refuse present an unsightly appearance and nuisance
from bad odours.

5. SOURCES OF SOLID WASTE
• Street refuse
• Market refuse
• Stable litter
• Industrial refuse
• Domestic refuse

6. STORAGE OF WASTE
• Galvanized steel dust bin with cover
(for households) – 0.05 to 0.1 cubic
feet per capita per day.
– A bin with capacity of 1.5 cubic feet for a
family of 5 members if collection is done
every 3 days.
• Public bins.

7. COLLECTION OF SOLID
WASTE
• House-to-house collection
• Mechanical transport
• Dustless refuse collector

8. METHODS OF
SOLID WASTE
DISPOSAL
• INSANITARY METHODS
• SANITARY METHODS

9. INSANITARY
METHOD
• DUMPING/HOG FEEDING
– Refuse dumped in low lying areas
– Bacterial action over time, decreases
volume of refuse which is gradually
converted into humus
– Disadvantages
• Smell
• Unsightly appearance
• Free access to flies, rodents, hogs, dogs etc.
• Dispersal by wind
• Pollution of surface and ground water

10. SANITARY
METHODS
Sanitary landfill/ Controlled tipping
Composting
Incineration
Manure pits
Burial
Biogas plant

11. SANITARY LANDFILL / CONTROLLED TIPPING
– Laying of dry and condensed refuse in a trench or
other prepared area with intervening earth coverings.
– Anaerobic digestion of the refuse takes place. The
process takes 4-6 months to complete.

13. • Trench method
– Level ground
– Trenches 4-12 m wide, 2-3 m deep
– Refuse is compacted and then covered with excavated earth
• Ramp method
– Sloping terrain
• Area method
– Land depressions, disused quarries, pits
– May need soil from outside sources to cover the compacted refuse

14. COMPOSTING
– Method of combined disposal of refuse and nightsoil
or sludge.
– Organic matter breaks down under bacterial action,
producing “compost” – used as manure.

15. METHODS OF
COMPOSTING
• 1. Bangalore Method
• 2. Mechanical
Composting
• 3. Vermicomposting

16. BANGALORE METHOD
 Anaerobic composting; also called “Hot fermentation process”
 IISc, Bangalore – Indian Council of Agriculture Research.
 Dry waste material of 25 cm thick is spread in a pit and a thick
suspension of cow dung in water is sprinkled over for moistening.
 A thin layer of dry waste is laid over the moistened layer.
 The pit is filled alternately with dry layers of material and cow dung
suspension till it rises 0.5 m above ground level.
 It is left exposed without covering for 15 days.
 It is given a turning, plastered with wet mud and left undisturbed for about
5 months or till required.

17. Anaerobic decomposition
4-6 months
Humus
NIGHTSOIL
15cm
5 cm
15cm5 cm25cm
REFUSE
REFUSE
NIGHTSOIL
REFUSE
Earth
NIGHTSOIL

18. MECHANICAL COMPOSTING
• The refuse is first cleared of salvageable materials such as rags,
bones, metal, glass and items which are likely to interfere with the
grinding operation.
• It is then pulverised in a pulverising equipment in order to reduce
the size of articles to less than 2 inches.
• The pulverised refuse is then mixed with sewage, sludge or
nightsoil in a rotating machine and incubated.
• The factors which are controlled in the operation are a certain
carbon nitrogen ratio, temperature, moisture, pH and aeration.
• The entire process of composting is complete in 4 to 6 weeks.

19. Refuse
Pulverizing equipment
Pulverized refuse + Sewage/Sludge/Nightsoil
Incubation
(Temperature, pH, Aeration, Moisture controlled)
Complete composting
Screening
4-6 weeks

20. VERMICOMPOSTING
• A method of garbage disposal
Garbage Earthworms
2-3 months
Compost

21. INCINERATION
– Suitable for areas where land is not available for
sanitary landfill
– Example: Hospitals
– Disadvantages:
• Expensive
• No useful by-product
• Air pollution

22. MANURE PITS
– Used in rural households
– Covered with earth after each days dumping
– Two pits
– Within 5-6 months decomposed refuse which is used
as fertilizer

23. BURIAL
– Suitable for small settlements/camps.
– A trench 1.5 m wide and 2 m deep is excavated,
and at the end of each day the refuse is covered
with 20 to 30 cm of earth.
– When the level in the trench is 40 cm from
ground level, the trench is filled with earth and
compacted, and a new trench is dug out.
– Decomposed matter may be ready for use as
manure within 4-6 months

24. BIOGAS PLANT
• Biogas is produced by
the anaerobic
breakdown of solid
waste /excreta.
• Biogas (Methane, CO2,
Hydrogen) can be used
as a fuel for any
heating purpose, such
as cooking

25. EXCRETA DISPOSAL

26. SPREAD
OF
DISEASES
FROM
EXCRETA

27. SANITATION
BARRIER

28. METHODS
OF
EXCRETA
DISPOSAL
• Service type- Conservancy system
(insanitary)
• Non-service type (sanitary)
• Bore Hole
• Dug well or Pit latrines
• Water seal type
• Septic tank
• Aqua Privy
• Latrines suitable for temporary use
• Shallow trench
• Deep trench
• Pit latrines
• Bore hole latrines
Unsewered areas
• Water carriage system
SEWERED AREAS

29. CONSERVANCY SYSTEM
• Cartage (Conservancy system)
• Example: Bucket latrine
• Disadvantages:
Smell
Flies
Health risk to people handling the excreta
Health risk from food crops fertilized with raw excreta
Bucket latrine

30. BORE HOLE
• The bore hole latrine is the forerunner of the
non-service type of latrines in this country.
• It was first introduced by the Rockefeller
foundation during 1930' s in campaigns of
hookworm control.
• The latrine consists of a circular hole 30 to 40
cm (12-16 in.) in diameter, dug vertically into
the ground to a depth of 4 to 8 m (13-26 ft.),
most commonly 6 m (20 ft.).
• A special equipment known as auger is
required to dig a bore hole. In loose and
sandy soils, the hole is lined with bamboo
matting or earthen-ware rings to prevent
caving in of the soil.
• A concrete squatting plate with a central
opening and foot rests is placed over the
hole.

31. SIMPLE PIT

32. SIMPLE
PIT
• Easy and cheap to construct
• Slab and shelter can be
reused
• Excreta are isolated
Advantages:
• Unpleasant odors
• Flies
Disadvantages:

33. VENTILATED
IMPROVED
PIT LATRINE

34. WINDSHEAR
EFFECT
DRAWING AIR
UP THE VENT
PIPE

35. WATER SEAL
• Pour flush latrines use a pit for excreta
disposal and have a special pan
provided with a “water-seal” of 20-30
mm.
• They need 1-3 liters of water for
flushing each time they are used.
• Advantages:
– No fly or smell problems
– Easy maintenance
• Disadvantages:
– Water is needed for their operation
– More expensive than pit latrines

36. WATER SEAL TYPE

37. DIRECT OR INDIRECT TYPE WS
LATRINES
Direct Indirect

38. SEPTIC TANK
• Septic tanks are watertight chambers
(single, double or multi chambered)
which receive excreta and wastewater.
• They are connected to a soakaway
which receives liquid overflowing from
the tank.

39. SEPTIC
TANK
• Isolation and treatment of excreta
• No odor or fly problems
• May be connected to sewerage system
at a later date
Advantages:
• High cost of construction
• Need for periodic mechanical emptying
• Need for large volumes of flushing
water
• Only suitable where flush toilets are
used
Disadvantages:

40. AQUA PRIVY
• The aquaprivy is a water tight tank filled
with water into which excreta fall via a
drop pipe, connected to a seepage pit
(soakaway) to dispose of sullage and
effluent.
• Drop pipe must reach below surface of
the water.

41. SEPTIC TANK
• Advantages:
– Cannot be blocked with bulky anal cleaning material
– Nil problem with odor or flies
– Can be connected to a sewerage system at a later date
• Disadvantages:
– Expensive to build
– Need large volumes of water to work
– Water seal may be hard to maintain
– Tanks must be emptied about every 3 years

42. SHALLOW TRENCH
• This is simply a trench dug with ordinary tools. The trench is 30 cm (1 ft.)
wide and 90-150 cm (3-5 ft.) deep.
• Its length depends on the number of users : 3-3.5 m (10-12 ft.) are
necessary for 100 people.
• Ablution water should be provided.
• The shallow trench is a rudimentary arrangement for a short period (upto
one week).
• When the trench is filled to 30 cm (12 in.) below ground level, it must be
covered with earth, heaped above ground level and compacted; if
necessary, a new trench must be dug

43. SHALLOW TRENCH

44. DEEP TRENCH
• This type of latrine is intended for camps of longer duration, from a
few weeks to a few months.
• The trench is 1.8 to 2.5 m (6-8 ft.) deep and 75-90 cm (30-35 in.)
wide.
• Depending upon the local customs, a seat or a squatting plate is
provided.
• A superstructure is built for privacy and protection.

45. DEEP TRENCH

46. SHULABH SHAUCHALAYA
• A low cost, water seal type of latrine connected to a 3’x3’x3’ pit. It is a
modified handflush latrine with a specially designed pan and trap –
needs very little water for flushing.
• Sulabh International, an NGO, maintains Sulabh Community Latrines –
‘pay-and-use system – in many parts of India.
• Sulabh International, the investors, not only build but also maintain the
system of Sulabh Community Latrines.
• Their usual structure is a lavatory block of several dozen seats, with a
bathing block adjoining.
• The system is to charge Rs. 5 per user. Delhi has opted for this system
in all its slums.
• This system has drawn praise from ecologists and planners.

47. CHEMICAL CLOSET
• It consists of a metal tank containing a disinfectant fluid
(Formaldehyde).
• A seat with cover is placed directly over the tank.
• Water should not be thrown into the tank.
• It has very limited use under Indian conditions.

48. COMPOSTING LATRINES
• Composting latrines are shallow vaults, into which excreta, kitchen
waste and similar wastes are added.
• The waste & excreta breakdown together to produce compost –
fertilizer.
• Two shallow vaults are usually provided - when one is full it is covered
with soil and left for at least two years – compost.
• The vaults must not receive water

49. COMPOSTING LATRINES
Advantages:
• Does not need to be moved
and new vaults do not have
to be dug.
• Produces compost used as a
fertilizer
• Disposes kitchen waste as
well
Disadvantages:
• More expensive and more
difficult to build than VIP or
WS latrine

50. WATER CARRIAGE SYSTEM
• The water carriage system or sewerage system implies collecting and
transporting of human excreta and waste water from residential,
commercial and industrial areas, by a net-work of underground pipes,
called sewers to the place of ultimate disposal.
• It is the method of choice for collecting and transporting sewage from
cities and towns where population density is high.
• Two types: Combined sewerage system and separate sewerage system
• In the combined system, the sewers carry both the sewage and surface
water.
• In the separate system, surface water is not admitted into sewers.
• The separate system is considered the system of choice today

51. DISPOSAL OF E-WASTE

52. E-WASTE
 It is a term used to describe old, end-of-life electronic appliances
and devices.
 Examples: computers, fax machines and copiers, televisions etc.
 They are often hazardous or toxic components that can impact
the environment once the materials end up in a landfill or if they
are improperly managed and disposed. E.g. arsenic, cadmium,
CFC etc.

53. RISKS OF E-WASTE
• E-waste contain hazardous heavy metals when disposed in the
open environment pose serious threat to human, animals and
plants.
• Most of the metals in e-waste are carcinogenic in nature.
• Amount of e-waste being produced including mobile phones and
computers could rise by as much as 500 percent over the next
decade in countries like India

54. HOW ELECTRONIC PRODUCTS BECOME
E-WASTE
• Rapid Development in Technology
• Changing design, fashion and trends in Mobile phone markets
• Attractive offers from manufacturers
• Shorter life of electronic products
• Increase in customers
• ICT culture in all fields

55. TOXIC CHEMICALS IN E-WASTE
• Lead – Affects Central and Peripheral Nervous system, Kidney
Damage, Inhibits oxygen carrying capacity of blood.
• Cadmium – Toxic, stores in Kidney, Neural damage.
• Mercury – Chronic damage to brain, Respiratory and skin
disorders.
• Chromium – DNA disorders, Asthma.
• Barium – Muscle weakness, kidney damage Beryllium – Lung
cancer, beryllicosis, skin diseases.
• PVC – Hormonal problems, Reproductive issues

56. E-WASTE DISPOSAL
• Landfill: The e-waste is piled up and covered with other domestic waste
and soil
• Incineration: The e-waste is burnt which produces toxic gases like
dioxins and furans. The toxic smoke released into the atmosphere
pollutes the air.
• Reuse: The electronic equipment goes for slight modification or may be
used as such. About 3%-5% of the computers are reused.
• Recycling: The e-waste goes for recycling after all the possibility for
reuse exhausted. The waste is used as raw material to other
manufacturing industry.

58. EFFECTIVE
MANAGEMENT
OF E-WASTE
• Massive awareness to consumers
• Setting up of more collection centres and collection points
• Manufactures responsibility to provide good standard materials and
assurance for recycling
• Fair Trade principles
• More recycling units by providing subsidized financial supports
• Proper training to Workers dealing recycling units
• Ban on importing e-waste from other countries
• Proper monitoring and evaluation system by the regulators in all
levels
• Sell or dump of e-waste only to government authorized recyclers
• Green and energy efficient devices by the manufactures
• Donate used electronics to charitable organizations
• Recovery of valuable metals like Cu, Al, Au, and Ag through
recycling
• Maintenance of data on e-waste
• Use of available best strategies
• Establishing a training centre for training the manpower
• Funding for research on recycling of e-waste

59. THANK YOU