Sewage
TreaTmenT
1
IntroductionIntroduction
The bulk of the biodegradable pollutants that can be released
into the environment is made up of:...
Two Phases Of Water Pollution
•Chemical pollution
•Physical pollution
3
4
Chemicals Pollution
Pesticides and fertilizers that contain nitrates and phosphates
are a source of chemicals that cause w...
Physical Pollution
Physical pollution is the release of contaminants into the
waterway of materials that can change the wa...
There are two forms:
1.liquid ,
2. solid.
Their sources:
1.private houses.
2.commercial buildings,
3.institutions like sch...
Domestic wastes
Composition:
• 99.9% of water by weight,
• Dissolved organic material
• Suspended solids
• Micro-organisms...
Organic materials Inorganic materials
Sodium Fats
Calcium Proteins
Magnesium Carbohydrates
Chlorine Detergents
Sulphates
B...
Two methods to detect the quality of the sewage:
 BOD5: biological oxygen demand in five days (expressed by
mg/L or g/m³ ...
Its objective is to produce an environmentally-safe fluid waste
stream (or treated effluent) and a solid waste (or treated...
The quality of the treated waste released from the treatment
system depends on:
the volume and condition of the receiving...
Sewage collection and treatment is typically subject to local,
state and federal regulations and standards. Industrial
sou...
Sewage treatment generally involves four stages:
1. primary treatment
2. secondary treatment and
3. tertiary treatment.
In...
The preliminary stage
Preliminary stage removes materials that can be easily
collected like large debris by using screens ...
The influent sewage water is screened to remove all large
objects like cans, rags, sticks, plastic packets etc. carried in...
17
Primary treatment stage
Primary treatment consists of temporarily holding the sewage in a
quiescent basin where heavy soli...
Secondary treatment stage
Secondary treatment removes dissolved and suspended
biological matter.
Secondary treatment is ty...
Secondary treatment stage
Secondary treatment may require a separation process to
remove the micro-organisms from the trea...
1. Fixed-film or attached growth systems include trickling
filters, Moving Bed Biofilm Reactors (MBBR), or rotating
biolog...
It is used in the secondary
treatment. A trickling filter consists
of a fixed bed of rocks, lava, gravel,
polyurethane foa...
Aerobic conditions are maintained
by splashing, diffusion, and either by
forced air flowing through the bed
or natural con...
Trickling Filters
24
25
26
27
28
Rotating biological contactors
2. Suspended-growth systems include activated sludge, where
the biomass is mixed with the sewage and can be operated in a
...
Suspended Film Systems:
– Stir and suspend microorganisms in
wastewater
– Settled out as a sludge
– Pumped back into the i...
Settle sewage from primary
sedimentation
Waste
Sludge
Air
Settlement
Effluent
Flow
Sludge
Sludge
recycled
31
Aeration
and rapid
mixing
Settling
collects sludge
on bottom
Secondary process
ir
iffuser
Fromprimaryprocess
Totertiarypro...
33
• In general, activated sludge like plants encompass a variety of
mechanisms and processes that offer dissolved oxygen to
...
Activated sludge:
•mixed community of microorganisms,
•Both aerobic and anaerobic bacteria may exist,
•Biological floc is ...
• The basic process is given below:
sewage + microorganisms + oxygen = growth of
microorganisms (biomass) + Carbon dioxide...
Settle sewage from primary
sedimentation
Waste
Sludge
Air
Settlement
Effluent
Flow
Sludge
Sludge
recycled
37
Physical components of activated sludge process
• Aeration tank
– oxygen is introduced into the system
• Aeration source
– ensure that adequate oxygen is fed into the tank
– provided pure oxygen or compressed air
• Secondary clarifiers
Activated-sludge solids separate from the surrounding
wastewater
• Activated sludge outflow
line
– Pump activated sludge
back to the aeration
tank
• Effluent outflow line
– discharged eff...
Sludge treatment and disposal
This treatment and disposal are applied by several ways that
include:
43
Disposal of
excess ...
Disposal of the excess sludge can be applied by:
44
3.
Composting
3. Ponds And Lagoons
A pond is a body of standing water, either natural or man-made,
that is usually smaller than a lake.
...
The enclosed body of water behind a barrier reef or barrier
islands or enclosed by an atoll reef is called a lagoon.
46
Ponds And Lagoons
Stabilization ponds or lagoons are also known as Oxidation
Ponds.
They are used for simple secondary tre...
The production of these minerals supports the growth of algae
in the oxidation pond. Growth of algal populations allows fu...
Disadvantages of Oxidation ponds
 Oxidation ponds tend to be inefficient
 Require large holding capacities
 The degrada...
50
Tertiary treatment: removing of phosphate, nitrate, and
pathogenic micro-organisms to produce potable water and to
prevent...
Tertiary treatment stage
52
53
Preliminary
treatment
Primary treatment
Secondary
treatment
Tertiary treatment
54
55
56
Sewage treatment
Upcoming SlideShare
Loading in...5
×

Sewage treatment

6,590

Published on

Sewage treatment lecture

Published in: Education, Technology
0 Comments
12 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
6,590
On Slideshare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
943
Comments
0
Likes
12
Embeds 0
No embeds

No notes for slide
  • -convection n. heat transfer by upward movement of a heated and less dense medium. [Latin veho vect- carry] -convector n. heating appliance that circulates warm air by convection.
  • -convection n. heat transfer by upward movement of a heated and less dense medium. [Latin veho vect- carry] -convector n. heating appliance that circulates warm air by convection.
  • -reef1 n. 1 ridge of rock or coral etc. at or near the surface of the sea. -atoll n. ring-shaped coral reef enclosing a lagoon. [Maldive] -coral island n. (also coral reef) island (or reef) formed by the growth of coral. -coral —n. hard red, pink, or white calcareous substance secreted by marine polyps for support and habitation. —adj. 1 red or pink, like coral. 2 made of coral. [Greek korallion]
  • Sewage treatment

    1. 1. Sewage TreaTmenT 1
    2. 2. IntroductionIntroduction The bulk of the biodegradable pollutants that can be released into the environment is made up of: 1. Domestic wastes 2. Institutional liquid waste 3. Industrial wastes 4. Agricultural wastes 2
    3. 3. Two Phases Of Water Pollution •Chemical pollution •Physical pollution 3
    4. 4. 4
    5. 5. Chemicals Pollution Pesticides and fertilizers that contain nitrates and phosphates are a source of chemicals that cause water pollution. These chemicals seep into the groundwater and mix with runoff moving to lakes and rivers. Chemical pollution is mainly industrial, with the release of acids, alkali and toxic compounds, which can poison the living organism in the waterways. 5
    6. 6. Physical Pollution Physical pollution is the release of contaminants into the waterway of materials that can change the water’s physical conditions, as the warm water which it is used for cooling in the industries. 6
    7. 7. There are two forms: 1.liquid , 2. solid. Their sources: 1.private houses. 2.commercial buildings, 3.institutions like schools and hospitals. 7
    8. 8. Domestic wastes Composition: • 99.9% of water by weight, • Dissolved organic material • Suspended solids • Micro-organisms (pathogens) and other components. 8
    9. 9. Organic materials Inorganic materials Sodium Fats Calcium Proteins Magnesium Carbohydrates Chlorine Detergents Sulphates Bicarbonates Nitrates Ammonia Traces of heavy metals 9 75% of solids and 40% of the dissolved material are organic.
    10. 10. Two methods to detect the quality of the sewage:  BOD5: biological oxygen demand in five days (expressed by mg/L or g/m³ at 25 ̊c for 5 days).  COD: chemical oxygen demand using an oxidizing agent. 10
    11. 11. Its objective is to produce an environmentally-safe fluid waste stream (or treated effluent) and a solid waste (or treated sludge) suitable for disposal or reuse (usually as farm fertilizer). 11
    12. 12. The quality of the treated waste released from the treatment system depends on: the volume and condition of the receiving water , its ability to dilute the waste. 12
    13. 13. Sewage collection and treatment is typically subject to local, state and federal regulations and standards. Industrial sources of wastewater often require specialized treatment processes. 13
    14. 14. Sewage treatment generally involves four stages: 1. primary treatment 2. secondary treatment and 3. tertiary treatment. In addition to these three, some scientists adds the preliminary stage to them obtaining by this four stages. 14 Sewage treatment stages
    15. 15. The preliminary stage Preliminary stage removes materials that can be easily collected like large debris by using screens and grit channels. 15
    16. 16. The influent sewage water is screened to remove all large objects like cans, rags, sticks, plastic packets etc. carried in the sewage stream. Pre-treatment may include a sand or grit channel where the velocity of the incoming wastewater is adjusted to allow the settlement of large debris. For small sanitary sewer systems, the grit chambers may not be necessary, but grit removal is desirable at larger plants 16
    17. 17. 17
    18. 18. Primary treatment stage Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment. 18
    19. 19. Secondary treatment stage Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is typically performed by micro-organisms in a managed habitat. 19
    20. 20. Secondary treatment stage Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment. Secondary treatment systems are classified as fixed-film or suspended-growth systems or ponds and lagoons . 20
    21. 21. 1. Fixed-film or attached growth systems include trickling filters, Moving Bed Biofilm Reactors (MBBR), or rotating biological contactors, where the biomass grows on media and the sewage passes over its surface. 21
    22. 22. It is used in the secondary treatment. A trickling filter consists of a fixed bed of rocks, lava, gravel, polyurethane foam, sphagnum peat moss, ceramic, or plastic media over which sewage or other wastewater flows downward and causes a layer of microbial slime (biofilm) to grow, covering the bed of media. 22 Trickling Filters
    23. 23. Aerobic conditions are maintained by splashing, diffusion, and either by forced air flowing through the bed or natural convection of air if the filter medium is porous. 23 Trickling Filters
    24. 24. Trickling Filters 24
    25. 25. 25
    26. 26. 26
    27. 27. 27
    28. 28. 28 Rotating biological contactors
    29. 29. 2. Suspended-growth systems include activated sludge, where the biomass is mixed with the sewage and can be operated in a smaller space than fixed-film systems that treat the same amount of water. However, fixed-film systems are more able to cope with drastic changes in the amount of biological material and can provide higher removal rates for organic material and suspended solids than suspended growth systems. 29
    30. 30. Suspended Film Systems: – Stir and suspend microorganisms in wastewater – Settled out as a sludge – Pumped back into the incoming wastewater – Ex: Activated sludge
    31. 31. Settle sewage from primary sedimentation Waste Sludge Air Settlement Effluent Flow Sludge Sludge recycled 31
    32. 32. Aeration and rapid mixing Settling collects sludge on bottom Secondary process ir iffuser Fromprimaryprocess Totertiaryprocess
    33. 33. 33
    34. 34. • In general, activated sludge like plants encompass a variety of mechanisms and processes that offer dissolved oxygen to promote the growth of microorganisms that substantially removes organic material. 34
    35. 35. Activated sludge: •mixed community of microorganisms, •Both aerobic and anaerobic bacteria may exist, •Biological floc is formed,
    36. 36. • The basic process is given below: sewage + microorganisms + oxygen = growth of microorganisms (biomass) + Carbon dioxide. 36 The result will be A nearly solid free water that can be discharged back into the river It can undergo further treatment (tertiary treatment) if the pollution level in it can still causes some risks. Or
    37. 37. Settle sewage from primary sedimentation Waste Sludge Air Settlement Effluent Flow Sludge Sludge recycled 37
    38. 38. Physical components of activated sludge process • Aeration tank – oxygen is introduced into the system
    39. 39. • Aeration source – ensure that adequate oxygen is fed into the tank – provided pure oxygen or compressed air
    40. 40. • Secondary clarifiers Activated-sludge solids separate from the surrounding wastewater
    41. 41. • Activated sludge outflow line – Pump activated sludge back to the aeration tank • Effluent outflow line – discharged effluent into bay or tertiary treatment plant
    42. 42. Sludge treatment and disposal This treatment and disposal are applied by several ways that include: 43 Disposal of excess sludge Reduction in sludge production
    43. 43. Disposal of the excess sludge can be applied by: 44 3. Composting
    44. 44. 3. Ponds And Lagoons A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. 45
    45. 45. The enclosed body of water behind a barrier reef or barrier islands or enclosed by an atoll reef is called a lagoon. 46
    46. 46. Ponds And Lagoons Stabilization ponds or lagoons are also known as Oxidation Ponds. They are used for simple secondary treatment of sewage effluents. Within an oxidation pond, heterotrophic bacteria degrade organic matter in the sewage which results in production of cellular material and minerals. 47
    47. 47. The production of these minerals supports the growth of algae in the oxidation pond. Growth of algal populations allows further decomposition of the organic matter by producing oxygen. The production of this oxygen replenishes the oxygen used by the heterotrophic bacteria. 48
    48. 48. Disadvantages of Oxidation ponds  Oxidation ponds tend to be inefficient  Require large holding capacities  The degradation is relatively slow  The effluents containing the oxidized products need to be periodically removed from the ponds. 49
    49. 49. 50
    50. 50. Tertiary treatment: removing of phosphate, nitrate, and pathogenic micro-organisms to produce potable water and to prevent eutrophication. Involving chemical precipitation, disinfection with chlorine, filtration through sand filters, and the use of maturation ponds. N.B: The purpose of disinfection in the treatment of waste water is to substantially reduce the number of microorganisms in the water to be discharged back into the environment. 51 Tertiary treatment stage
    51. 51. Tertiary treatment stage 52
    52. 52. 53
    53. 53. Preliminary treatment Primary treatment Secondary treatment Tertiary treatment 54
    54. 54. 55
    55. 55. 56
    1. A particular slide catching your eye?

      Clipping is a handy way to collect important slides you want to go back to later.

    ×