Composting and land fill related questions discussion

1. Sanitary Chemist
Topic: Solid Waste Management- Composting

2. Question 1

3. Explanation

4. Question 2

5. Explanation

6. Question 3

7. Explanation

8. Question 4

9. Explanation

10. Question 5

11. Explanation

12. Question 6

13. Explanation

15. Question 7

16. Explanation

19. Question 8

20. Explanation
 Field composting and windrow composting is a type of non-reactor
system of classification of the composting systems.
 Field composting doesn’t use thermal disinfection method as it lacks
self-heating mechanism due to its exposure to a larger surface area
and the waste having sanitation problem cannot be used for
composting in this method
 Field composting is the simplest way of microbial composting which
takes place in a very thin layer above the soil surface.
 Horizontal reactor, vertical reactor are major types of reactor
system for microbial composting.
 In vertical reactor, the waste flows vertically with mass flow in a
vertical direction.
 Waste is loaded into a horizontal reactor composting system with a
wheel loader.

21. Question 9

22. Explanation
 Vermicomposting uses earthworms for composting
by degrading the organic wastes present in the bulk
waste material by various methods.
 The major objective is to obtain products free of
any pollutants and hence, toxic products are
eliminated in the process, and the other two
objectives of Vermicomposting are to elevate the
value of original material and to accelerate the
rate of degradation.

23. Question 10

24. Explanation
 Low growth rate is not seen in earthworms selected for
Vermicomposting as they have a high growth rate.
 The digestion rate and absorption rate of the consumed food
by earthworms is high.
 They can very well adapt to the changing environmental
conditions, that makes them more suitable for
Vermicomposting.

25. Question 11

26. Explanation
 Plasmodium species is a malaria parasite and is
not a species of earthworms.
 Epifilis, Endogens, Aneciques are the most
common species of earthworms used as
Vermicomposting earthworms, some with dark
pigments and some with uniform coloration
having high growth rate, the digestion rate and
absorption rate of the consumed food by
earthworms is high and they can very well adapt
to the changing environmental conditions.

27. Question 12

28. Explanation
 The major environmental concern related to
landfill is the discharge of leachates into the
immediate environment which pose a great threat
to the environment, so, the major concern is to
control it, whereas, limited space, technology and
man-power do not pose environmental threat.

30. Question 13

31. Explanation
 Biodegradable are substances capable of being broken
down by living organisms such as bacteria and other
microorganisms.
 Examples include- Food Products, Paper, Organic Waste,
Cow dung, Paper, etc. Humans manufacture many products
that get wasted and thrown away, causing a lot of harm to
the environment.
 The living organism breaks down the ‘biodegradable’ wastes
through biological processes.
 A few examples of Biodegradable wastes are: Papers,
Human waste, Sewage sludge, Dead animals and plants,
Hospital waste, Food waste, Manure, Starch-based plastics,
Natural fibers reinforce plastic, Slaughterhouse waste etc.

32. Question 14

33. Explanation
 Land filling is a process of disposal of solid waste
under the soil.
 It is usually done in low lying areas to prevent
unhygienic conditions.

34. Question 15

35. Explanation
 Land fill gases are produced during the
dumping of waste.
 They are foul smell creating unhygienic
conditions.

36. Question 16

37. Explanation

44. Question 17

45. Explanation

50. Question 18

51. Explanation
 Food waste can be decomposed by bacteria as they are
biodegradable waste.
Ashes and glass are non biodegradable
Microbes can easily decompose organic matter like
vegetable and fruit peels, animal and plant waste,
dead leaves, plants, and animals. Plastics generally
cannot be decomposed by microbes.

52. Question 19

53. Explanation
Organic waste is formed into rows of long piles called
“windrows” and aerated by turning the pile
periodically by either manual or mechanical means.
The ideal pile height, which is between 4 and 8 feet,
allows for a pile large enough to generate sufficient
heat and maintain temperatures, yet small enough to
allow oxygen to flow to the windrow's core. The ideal
pile width is between 14 and 16 feet.

54. Question 20

55. Explanation
 Compost is a mixture of organic residues (manure,
animal carcasses, straw, etc.) that have been
piled, mixed and moistened to undergo
thermophilic decomposition
 Leaves are perhaps the best material because of
their availability and organic content; however,
other types of organic materials such as animal
manures, grass clippings, vegetable refuse, small
tree limbs and shrub trimmings, coffee grounds,
and rotted sawdust are considered good
composting materials.

56. Question 21

57. Explanation

58. Explanation
 Worms will eat a wide variety of organic materials such
as paper, manure, fruit and vegetable waste, grains,
coffee grounds, kitchen waste, plant materials, and
ground yard wastes.
 As the organic matter passes through the gizzard of
the earthworm it is grounded into a fine powder after
which the digestive enzymes, microorganisms and
other fermenting substances act on them further aiding
their breakdown within the gut, and finally passes out in
the form of “casts”which are later acted upon by
earthworm gut associated microbes converting them
into mature product, the “vermicomposts”.

59. Question 22

60. Explanation
 Eisenia fetida, commonly known as the red
wigglers or red earthworms, are widely considered
to be the best species for vermicomposting
because of several key reasons: Optimal
temperature and moisture conditions: Red wigglers
are well adapted to the warm, moist conditions that
are ideal for vermicomposting.
 Redworms (Lubricous rubellus), Perionyx
excavatus (Indian blueworm) and Eudrilus
eugeniae (African night crawler) can also be used
effectively.

61. Question 23

62. Explanation
 The worm castings are very important to the
fertility of the soil.
 The castings contain high amounts of nitrogen,
potassium, phosphorus, calcium, and magnesium.
 In addition to micronutrients, advantageous soil
bacteria, and hormones involved in plant growth &
enzymes, vermicompost is a rich source of NKP
(nitrogen 2-3%, potassium 1.85-2.25%, and
phosphorus 1.55-2.25%).

63. Question 24

64. Explanation

65. Question 25

66. Explanation

67. Thank You