wastewater story

1. WASTEWATER STORY

2. What is Wastewater?
•Water rich in lather, mixed with oil, black-
brown water that goes down the drains from
sinks, showers, toilets, laundries.
• It refers to all effluents from a household,
hospitals, industries and so on.
• Effluent is used to refer to the liquid waste or
sewage that is discharged into water bodies
either from treatment plants or directly.

3. WATER – OUR LIFELINE
• We all need clean water , however, not all can
access the same
• Hence, it is necessary not only to preserve water
but clean the used water before dumping it into
the seas or any other water body.
• That’s why the United Nations proclaimed the
period between 2005 to 2015 as the International
decade for action on ‘Water for life’.

4. SEWAGE
A liquid waste containing a complex mixture
of suspended solids, organic and inorganic
impurities, nutrients, saprophytic and disease
causing bacteria and some other microbes.

5. COMPOSITION OF SEWAGE
TYPES OF IMPURIETIES EXAMPLES
ORGANIC IMPURITIES HUMAN FAECES, ANIMAL WASTES, OIL, UREA
(URINE), PESTICIDES, HERBICIDES, FRUITS AND
VEGETABLES
INORGANIC IMPURITIES NITRATES, PHOSPHATES, METALS
NUTRIENTS PHOSPHOROUS AND NITROGEN
BACTERIA VIBRIO CHOLERAE CAUSES CHOLERA,
SALMONELLA TYPHI CAUSES TYPHOID
OTHER MICROBES PROTOZOA CAUSING DYSENTRY

6. SEWERAGE
• The network of big and small pipes, called
sewers, from the sewerage.

7. SEWAGE TREATMENT
The process of
removing impurities
from waste water
before it can be
reused or sent to the
water bodies is
called sewage
treatment or
cleaning of water.

8. • Wastewater is passed through bar screen.
Large objects like rags, sticks, cans , plastic –
packets, napkins can be removed.

9. • Water then goes into a grit and sand removal
tank. The speed of the incoming wastewater is
decreased to allow sand, grit and pebbles to
settle down.

10. • Water is then allowed to settle in a large tank
which is sloped towards the middle. Solids like
faeces settle at the bottom and are removed
with a scraper. This is the sludge. A skimmer
removes the floatable solids like oil and
grease. Water so cleared is called clarified
water.

11. • The sludge is decomposed by the anaerobic bacteria
and the biogas produced in the process can be used
as fuel or can be used to produce electricity.
• The clarified water moves to the Aerator , where air
is pumped into it to help aerobic bacteria to grow,
which consumes human waste, food waste, soaps
and other unwanted matter still remaining in
clarified water and cleaning it further.

12. • After several hours, the suspended microbes
settle at the bottom of the tank as activated
sludge. The water is then removed from the top.
• The activated sludge is bout 97% water. The
water is removed by sand drying beds or
machines. Dried sludge is used as manure,
returning organic matter and nutrients to the soil.
The treated water has a very low level of organic
material and suspended matter. It is discharged
into a sea, a river or into the ground. Nature
cleans it up further. Sometimes, it is necessary to
disinfect water with chemicals like chlorine and
ozone before releasing it into the distribution
system.

13. BETTER HOUSEKEEPING PRACTICES
• Cooking oil and fats should not be thrown down the
drain. They can harden and block the pipes.
• chemicals like paints, solvents, insecticides, motor
oil, medicines may kill microbes that help purify
water.
• Used tea leaves, solid food remains, soft toys, cotton,
sanitary towels should be thrown in dustbins.

14. VERMI PROCESSING TOILETS
Vermi-processing toilet is a type of toilet which
treats human excreta by earthworms. Earthworms
turn human excreta into a cake of vermin which
serves a good variety of natural manure. It provides
the proper disposal of human excreta thus avoiding
pollution of the ecosystem outside.

15. SANITATION
• Poor sanitation contaminated drinking water is
the cause of a large number of diseases.
• Defecation in open or in water bodies can cause
soil pollution as well as water pollution.
• Both the surface water and ground water get
polluted.
• Ground water is the source of water for wells,
tubewells, springs and many rivers.
• Causes water borne diseases like cholera,
typhoid, polio, meningitis, hepatitis and dysentry

16. SEWAGE DISPOSAL ALTERNATIVES
• CHEMICAL
TOILET
SEPTIC TANK COMPOSTING PITS

17. THANK YOU