This document provides an overview of effluent treatment plants (ETPs). It discusses the need for ETPs, their design considerations and types. It describes the key processes involved in industrial wastewater treatment and sewage treatment. These include physical, chemical and biological treatment levels and mechanisms like screening, sedimentation, aeration, activated sludge etc. The document includes a flow chart illustrating the ETP treatment process.

1. Wastewater Treatment by Effluent
Treatment Plants
By...
Rifat
Student of Southeast University
Department : Pharmacy

2. Content
• Introduction
• Need of ETP
• Design of ETP
• Types of ETP
• Industrial Wastewater Treatment
• Swage Treatment
• Treatment level
• Treatment Mechanism
• Conclusion

3. Introduction
What is an ETP?
ETP or effluent treatment plant is used to treat the industrial waste water.
Influent: Untreated industrial waste water.
Effluent: treated industrial waste water.
Sludge: solid part separated from waste water by etp.

4. Need of ETP
• To clean industry effluent and recycle it for further use.
• To reduce the usage of fresh/potable water in Industries.
• To cut expenditure on water procurement.
• To preserve natural environment against pollution
• To meet the Standards for emission or discharge of environmental pollutants
• To safeguard environment against pollution and contribute in sustainable
development.

5. Design of ETP
• The design and size of the ETP depends upon:
– Quantity and quality of the industries discharge effluent.
– Land availability
– Monetary considerations for construction, operation & maintenance.
• Area dimension depends on:
– Quality of wastewater to be treated
– Flow rate
– Type of biological treatment to be used.
• In case of less available land, CETP (Common Effluent Treatment Plant) is preferred over ETP

6. Types of Effluent
• Industrial wastewater treatment
• sewage treatment

7. Industrial wastewater treatment
• Industrial wastewater treatment covers the
mechanisms and processes used to treat waters that
have been contaminated in some way by
anthropogenic industrial or commercial activities
prior to its release into the environment or its re-
use.

8. Sources of industrial wastewater
• Agricultural waste
• Iron and steel industry
• Mines and quarries
• Food industry
• Complex organic chemicals industry
• Nuclear industry

9. Sewage Treatment
• It includes physical, chemical, and biological processes to remove
physical, chemical and biological contaminants.
• Its objective is to produce an environmentally-safe fluid waste stream
and a solid waste suitable for disposal or reuse (usually as farm
fertilizer).
• Using advanced technology it is now possible to re-use sewage effluent
for drinking water

10. Origins of Sewage
• Sewage is generated by residential, institutional, and
commercial and industrial establishments.
• It includes household waste liquid from toilets, baths, showers,
kitchens, sinks and so forth that is disposed of via sewers.
• In many areas, sewage also includes liquid waste from industry
and commerce.

11. Process overview
• Pre Treatment
• Screening
• Grit Removal
• Flow Equalization
• Fat & Grease Removal
• Primary Treatment
• Secondary Treatment
• Tertiary Treatment

12. Pre Treatment
• Pre-treatment removes materials that
– can be easily collected from the raw waste water
before they damage or
– clog the pumps and skimmers of primary treatment
clarifiers (trash, tree limbs, leaves, etc.).

13. Screening
• The influent sewage water is screened to remove all large objects like cans,
rags, sticks, plastic packets etc. carried in these wage stream.
• This is most commonly done with an automated mechanically raked bar
screen
• The solids are collected and later disposed in a landfill or incinerated.
• Bar screens or mesh screens of varying sizes may be used to optimize solids
removal.

15. Grit Removal
• Pre-treatment may adjusted to allow the
settlement of sand, grit, stones, and broken
glass.
• These particles are removed because they may
damage pumps and other equipment.
• Grit removal is desirable at larger plants.

16. Flow Equalization
• Equalization basins maybe used for temporary storage of diurnal or wet-weather
flow peaks.
• Basins provide a place to temporarily hold incoming sewage during plant
maintenance.
• Flow equalization basins require variable discharge control, typically include
provisions for bypass and cleaning, and may also include aerators.
• Cleaning may be easier if the basin is downstream of screening and grit removal.

18. Fat & Grease Removal
• In some larger plants, fat and grease is removed by passing the
sewage through as tank where skimmers collect the fat floating on
the surface.
• Air blowers in the base of the tank may also be used to help recover
the fat as froth.
• Many plants, however, use primary clarifiers with mechanical
surface skimmers for fat and grease removal.

19. Treatment Levels & Mechanisms of ETP
• Treatment levels:
– Preliminary
– Primary
– Secondary
– Tertiary (or advanced)
• Treatment mechanisms:
– Physical
– Chemical
– Biological

21. Preliminary Treatment level
• Purpose:
– Physical separation of big sized impurities like cloth, plastics, wood logs, paper,
etc.
• Common physical limit operations:
– Screening: A screen with openings of uniform size is used to remove large solids
such as plastics, cloth etc. Generally maximum 10mm is used.
– Sedimentation: Physical water treatment process using gravity to remove
suspended solids from water.
– Clearification: Used for separation of solids from fluids.

22. Primary Treatment Level
• Purpose:
– Removal of floating and settle able materials such as suspended solids and organic
matter.
• Methods:
– Both physical and chemical methods are used in this treatment level.
• Chemical unit processes:
– Chemical unit processes are always used with physical operations and may also be
used with biological treatment processes.
– Chemical processes use the addition of chemicals to the wastewater to bring
about changes in its quality.
– Example: pH control, coagulation, chemical precipitation and oxidation.

23. Aeration
• The activated sludge process is the most common option in
secondary treatment.
• Aeration in an activated sludge process is based on pumping air
into a tank, which promotes the microbial growth in the
wastewater.
• The microbes feed on the organic material, forming flocs which can
easily settle out.

24. Secondary Treatment Level
• Methods: Biological and chemical processes are involved in this
level.
• Biological unit process
– To remove, or reduce the concentration of organic and inorganic
compounds.
– Biological treatment process can take many forms but all are based
around microorganisms, mainly bacteria.

25. Secondary Treatment Level
• Aerobic Processes
– Aerobic treatment processes take place in the presence of air (oxygen).
– Utilizes those microorganisms (aerobes), which use molecular/free oxygen to
assimilate organic impurities i.e. convert them in to carbon dioxide, water and
biomass.
• Anaerobic Processes
– The anaerobic treatment processes take place in the absence of air (oxygen).
– Utilizes microorganisms (an aerobes) which do not require air (molecular/free
oxygen) to assimilate organic impurities.
– The final products are methane and biomass.

26. Tertiary / Advanced Treatment
• Purpose:
– Final cleaning process that improves wastewater quality before it is reused,
recycled or discharged to the environment.
• Mechanism:
– Removes remaining inorganic compounds, and substances, such as the
nitrogen and phosphorus. Bacteria, viruses and parasites, which are harmful to
public health, are also removed at this stage.

27. Tertiary / Advanced Treatment
• Methods:
– Alum: Used to help remove additional phosphorus particles and group the
remaining solids together for easy removal in the filters.
– Chlorine contact tank disinfects the tertiary treated wastewater by
removing microorganisms in treated wastewater including bacteria, viruses
and parasites.
– Remaining chlorine is removed by adding sodium bisulphate just before it's
discharged.

28. Flow chart for ETP

29. Activated sludge
• In general, activated sludge plants encompass a variety of
mechanisms and processes that use dissolved oxygen to promote
the growth of biological flocs that substantially removes organic
material.
• The process traps particulate material and can, under ideal
conditions, convert ammonia to nitrite and nitrate ultimately to
nitrogen gas.

30. Treatment mechanisms
• Treatment mechanisms:
– Physical
– Chemical
– Biological

31. Physical Unit Operations
• Common physical unit operations include among
other processes
– screening,
– flow equalization,
– sedimentation,
– clarification and
– aeration.

32. Chemical Unit Processes
• It is possible to have a purely physico-chemical plant with
no biological treatment.
• Chemical processes use the addition of chemicals to the
wastewater to bring about changes in its quality.
• They include pH control, coagulation, chemical
precipitation and oxidation.

33. Biological Unit Processes
• Treats wastewater from either municipality or industry having
soluble organic impurities or a mix of the two types of wastewater
sources.
• The obvious economic advantage, both in terms of capital
investment and operating costs, of biological treatment over other
treatment processes like chemical oxidation; thermal oxidation etc.

34. Conclusion
• Waste water treatment is an important initiative which has to betaken
more seriously for the betterment of the society and our future.
• Wastewater treatment method is categorized into three sub-divisions.
physical, chemical and biological.
• The construction sites consist of Effluent Treatment Plant (ETP),
whereas there is also for provision of Industrial & Sewage Treatment
Plant.