biotechnological approaches for advanced water treatment technology of raw water and sewage water

1. SEMINAR ON BIOTECHNOLOGICAL
APPROACHES FOR ADVANCED
WATER TREATMENT TECHNOLOGY
BY AYSHATHUL FEMITHA
2ND SEMESTER MHA

2. WATER TREATMENT
• Water treatment is any process that improves
the quality of water to make it more acceptable for a
specific end-use.
• The end use may be drinking, industrial water
supply, irrigation, river flow maintenance, water
recreation or many other uses, including being safely
returned to the environment.

3. • Water treatment removes contaminants and
undesirable components, or reduces their
concentration so that the water becomes fit for its
desired end-use.
• This treatment is crucial to human health and allows
humans to benefit from both drinking and irrigation
use.

4. • Water treatment has assumed importance in recent
years with the increasing demand on this limited
resource
• And also pollution parameters arising out of
discharge from untreated/partially treated effluents.
• Evolving new technologies for waster treatment have
necessarily received attention more than ever
before.

5. TREATMENT BIOTECHNOLOGY FOR RAW
WATER
• Raw water drawn from various sources is not
fit enough for human consumption directly
without subjecting it to treatment.

6. • The advanced technologies available in India
for treatment of municipal water supplies, for
industry or for large communities includes the
following:
Ultra-filtration
Flocculation
Reverse-osmosis

7. ULTRA-FILTRATION
• Ultra filtration (UF) is a variety of membrane filtration in
in which forces like pressure or concentration
gradients lead to a separation through a semipermeable
membrane.
• Suspended solids and solutes of high molecular
weight are retained in the so-called retentate, while
water and low molecular weight solutes pass through
the membrane in the permeate(filtrate).

8. FLOCCULATION
• The particles have a neutral charge and can stick
together.
• The water flows into a tank with paddles that provide
slow mixing and bring the small particles together to
form larger particles called flocs.
• Flocs will then sediment and are separated

9. REVERSE-OSMOSIS
• Reverse Osmosis (RO) is a water treatment process
that removes contaminants from water by using
pressure to force water molecules through a
semipermeable membrane.

10. TREATMENT TECHNOLOGY FOR
WASTEWATER
• The objective of wastewater treatment is to
remove the impurities and
• To reduce pollution in order to return the
effluent to the environment without causing
unacceptable damage to land, air or water
bodies

11. HOW TO ACCOMPLISH WASTEWATER
TREATMENT
 Trickling Filter
 Rotating Biological Contactor
 Activated Sludge Process
 Oxidation Ponds

12. • Microorganisms are used to destroy waste
materials
 Bacteria (aerobic and anaerobic)
 Fungi
 Algae
 Actinomycetes (filamentous bacteria).

13. TRICKLING FILTER
• Trickling filter is a bed of crushed rock, ~2m thick. Wastewater
is sprayed on the top (UWI plant).
• Liquid slowly passes through the rock, organic matter absorbs
to the rock and microbial growth takes place.
• Complete mineralization of organic matter takes place.

14. ROTATING BIOLOGICAL CONTACTOR
• A rotating biological contactor is a type of secondary
(Biological) treatment process. It consists of a series of closely
spaced, parallel discs mounted on a rotating shaft which is
supported just above the surface of the waste water.
• Microorganisms grow on the surface of the discs
where biological degradation of the wastewater pollutants
takes place.

15. ACTIVATED SLUDGE
• Microbial activity is taking place in activated sludge. Slime
forming bacteria like Zoogloea grow and form flocs. Small
animals and protozoa attach to these.
• Process of oxidation is similar to the trickling bed. Effluent
containing flocs goes to settling tanks.
• Flocs settle, Some floc material is recirculated.
• Main process is absorption of organic matter to the floc. BOD
of liquid waste is reduced by ~95%.

17. OXIDATION PONDS
• This is very simple treatment used in rural
areas, particularly suited for tropical areas
• Take up a large area, are less than 3m deep
(allow light to penetrate).
• There are odour problems and the process can
take over a week.

18. • The bacteria in the pond oxidise the various organic
material producing carbondioxide, ammonia and water.
• The algae grow by utilizing the inorganic material and
carbon dioxide in the presence of sunlight.
• The oxygen requirement for oxidation of the organic
matter by bacteria is satisfied mainly by oxygen released
by the algae.