The document discusses sewage treatment processes. It defines sewage treatment as aiming to remove contaminants from wastewater. The processes include primary treatment to settle and remove solids and grease; secondary treatment using microorganisms to biologically treat wastewater aerobically or anaerobically; and tertiary treatment to remove nutrients like nitrogen and phosphorus using filtration, membranes, or advanced oxidation. The advantages are reducing disease risk, low cost, and minimal odor and maintenance; disadvantages include odor, bacteria, installation costs, and potential air pollution.

1. Submitted by,
AISHWARYA.P

2. CONTENTS:
Introduction
Definition
Terminology
Causes for sewage and pollutants
Process
Advantages
Disadvantages

3. INTRODUCTION:
 Sewage treatment is a type
of waste water treatment
which aims to remove
contaminants from sewage
 Sewage contains
wastewater from households
and businesses and
possibly pre-treated
wastewater.

4. DEFINITION:
 Water treatment is any process that improves
the quality of water to make it appropriate for a
specific end-use.

5. TERMINOLOGY:
 The term “sewage treatment plant” is nowadays
often replaced with the term “wastewater treatment
plant” or “wastewater treatment station”.
 Sewage can be treated close to where the sewage
is created, which may be called a “Decentralized”
system or even an “on-site” system.

6. PROCESS:
SEWAGE
TREATMENT
PRIMARY
TREATMENT
SECONDARY
TREATMENT
TERTIARY
TREATMENT

8. PRIMARY TREATMENT:
 In the primary sedimentation
stage, sewage flows through
large tanks ,commonly called
“pre-settling basins”(or) “primary
clarifiers”.
 The tanks are used to settle
sludge while grease and oils
rise to the surface and are
skimmed off.

9. PRIMARY TREATMENT:
 Primary settling tanks are usually equipped with
mechanical driven scrapers that continually drive
the collected sludge towards a hopper in the base
of tank where it is pumped to sludge treatment
facilities.
 Grease and oil from the floating material can
sometimes be recovered for saponification.

10. SECONDARY TREATMENT:
 Secondary wastewater treatment
processes use microorganisms to
biologically remove contaminants from
wastewater.
 Secondary biological processes can be
aerobic (or) anaerobic, each process
utilizing a different type of bacteria
community.

11. SECONDARY TREATMENT:
AEROBIC:
 Aerobic biological processes are common in
municipal wastewater treatment.
 In an aerobic system, the organic
contaminants are converted to carbon
dioxide, water, additional microorganisms,
and other end products.

12. SECONDARY TREATMENT:
AEROBIC LAGOONS:
 Lagoons are typically large, shallow earthen
basins that provide adequate residence time for
the wastewater to be treated naturally by both
bacteria and algae.
ACTIVATED SLUDGE:
 A suspended-growth aerobic biological process
in which microorganisms remove carbonaceous
matter from wastewater in an aerobic
environment.

13. SECONDARY TREATMENT:
ACTIVATED SLUDGE:
 A suspended-growth
aerobic biological process
in which microorganisms
remove carbonaceous
matter from wastewater in
an aerobic environment.

14. SECONDARY TREATMENT:
BIOLOGICAL CONTACTOR:
An attached-growth process consisting of a
series of closely spaced, parallel discs mounted on a
rotating shaft which is partially submerged in the
wastewater being treated.
TRICKLING FILTER:
An attached-growth process where
wastewater is distributed over a fixed bed of media
such as rocks, plastics etc.

15. SECONDARY TREATMENT:
ANAEROBIC:
 Anaerobic biological treatment processes employ
organisms that function in the absence of molecular
oxygen.
 Anaerobic processes convert organic contaminants
to a biofuel gas comprising carbon dioxide, methane,
and other end products.
 Anaerobic processes are loosely organized as either
suspended or attached-growth systems.

16. TERTIARY TREATMENT:
 Tertiary treatment of
wastewater is the third
stage of the wastewater
treatment and is also known
as Advanced treatment.
 It removes the load of
nitrogen and phosphours
present in the water

17. TERTIARY TREATMENT:
FILTRATION PROCESS:
Filtration process removes the particulate
matter by passing water through the porous media.
• The filtration process consists of different types of
media which are usually made up of sand, gravel
and charcoal.
• There are two types of sand filtration:
* slow sand filtration
* Rapid sand filtration

18. TERTIARY TREATMENT:
 MEMBRANE PROCESS:
Membrane technology is used to
treat a variety of wastes including sewage, organic
and inorganic matter and water-soluble oil wastes.
 ADVANCED OXIDATION SYSTEM:
Ozone is introduced in the process
to destroy microorganisms and degrade organic
pollutant. Ozone (O3) is formed by passing oxygen
through a high voltage electric field.

20. ADVANTAGES:
 Rids Potential Diseases.
 Low-cost
 Minimal Odour Emissions
 No water Bills
 Little Maintenance
 Break down Solids Faster
 Less wasteful

21. DISADVANTAGES:
 Smelly
 Bacteria
 Space
 Installation costs
 Power
 Sporadic use
 It causes air pollution to the nearer homes.

22. THANK
YOU