Environmental Engineering

1. ENVIRONMENTAL
ENGINEERING

2. Section 5: Environmental Engineering
Water and Waste Water Quality and Treatment:
• Basics of water quality standards – Physical, chemical
and biological parameters; Water quality index; Unit
processes and operations; Water requirement; Water
distribution system; Drinking water treatment.
• Sewerage system design, quantity of domestic
wastewater, primary and secondary treatment. Effluent
discharge standards; Sludge disposal; Reuse of treated
sewage for different applications.
GATE Contents

3. Section 5: Environmental Engineering
Air Pollution:
• Types of pollutants, their sources and impacts, air
pollution control, air quality standards, Air quality Index
and limits.
Municipal Solid Wastes:
• Characteristics, generation, collection and
transportation of solid wastes, engineered systems for
solid waste management (reuse/ recycle, energy
recovery, treatment and disposal).
GATE Contents

4. Environmental Engineering : 10 to 12
Contents Wise:
Water and Waste Water Quality and Treatment: 7 to 8
Air Pollution: 1 to 2
Municipal Solid Wastes: 1 to 2
Expected Paper Weightage

5. Section 5: Environmental Engineering

6. • Every organism in this earth is surrounded by a lot of
things; say other organisms, plants, water, air, light,
land etc.
• These surroundings of the organism, all the living and
non-living things constitute its environment
• Definition: Environment is a combination of various
physical and biological elements that affect the life of an
organism.
Introduction

7. • Water is one of the most important substances on earth.
• All plants and animals must have water to survive.
• If there was no water there would be no life on earth.
The Importance of Water

8. Plants and animals need water.

9. • It is most important that the water which people drink
and use for other purposes is clean water.
• This means that the water must be free of germs and
chemicals and be clear.
• Water that is safe for drinking is called potable water.
• If the water is not safe to drink it is treated.
• All the action taken to make sure that drinking water is
potable is called water treatment.
The Importance of Water

10. 1. Surface sources
i) Ponds and lakes
ii) Stream and rivers
iii) Storage reservoir
iv) Ocean, generally not used for
water supplies at present
technologies are available
2. Sub surface water
sources or underground
sources
i) Springs
ii) Infiltration wells and
iii) Wells and rife wells
Water Sources
Raw water sources: The various sources of water can be
classified into two categories

11. • Water quality and standards are defined on the basis of
analyzing the raw water on their
Physical Parameters
Chemical Parameters
Biological Parameters
Quality Standards of Water

12. I. Turbidity
II. Colour
III. Taste and Odour
IV. Temperature
V. Specific conductance
Physical Quality Parameters

13. • If a large amount of solids are present in water it will
appear turbid in appearance.
• Turbidity depends upon the finesse and concentration
of particles present in water
• It is expressed as the amount of suspended solids in
mg/L or ppm
I. Turbidity

14. • Measurement
(a) For field – Turbidity rod
(b) For Lab – (i) Jackson’s turbidity meter
(ii) Nephelometer is used for treated water.
Nephelometer can measure turbidity less than 1 ppm
Nephelometer Turbidity Unit (NTU)
The IS value for drinking water is 10 – 25 NTU
I. Turbidity

15. Q. Turbidity of raw water is a measure of
A. suspended solids
B. acidity of water
C. B.O.D.
D. none of these.
I. Turbidity

16. Q. Turbidity of water may be caused due to
A. Suspended clay
B. Suspended silt
C. Finely divided organic material
D. All the above.
I. Turbidity

17. • Dissolved organic material from decaying vegetation or
inorganic materials may import colour to the water.
• Pure water is colourless, colour mainly due to
suspended matter (apparent colour), due to dissolved
solids (true colour)
II. Colour:

18. • The standard unit of colour is that which is produce by
“one mg of platinum cobalt” dissolved in one liter of
distilled water
• The IS value for treated water is 5 to 25 cobalt unit.
II. Colour:

19. • Pure water is odour and taste less.
• Mostly organic and inorganic material originating from
municipal or industrial waste contribute taste and
odour to the water.
• Taste and odour can be expressed in terms of odour
intensity and Threshold Odour Number (TON).
TON = (A+B)/ A
Where, A= Volume of sample in ml & B= Volume of distilled
water
For public supply TON below 3.
Osmoscope used for odour test.
III. Taste and Odour:

20. III. Taste and Odour:
Q

21. Q. Maximum threshold number permitted for indicating
the odour of public water supplies, is
A.1
B.2
C.3
D.4
III. Taste and Odour:

22. Q. The threshold odour number (TON) for a water sample
of 40 ml, diluted to standard 200 ml mixture, in which
odour is just barely detectable to the sense of smell, is
a) 8 b) 5
c) 50 d) None of these
• Threshold odour number represents the dilution ratio at which the odour
is hardly detectable
• TON = (A+B)/ A
Where, A= Volume of sample in ml & B= Volume of distilled water
TON = 200/40= 5
III. Taste and Odour:

23. • The increase in temperature decreases palatability
(pleasant in taste), because at high temperature CO2
and some other volatile gases are expelled.
• The ideal temperature of water for drinking purpose is
5˚c to 12˚c.
• Temperature around 10˚c desirable, above 25˚c
objectionable.
IV. Temperature:

24. • Presence of salt can be estimated by measuring specific
conductivity.
• Conductivity gives idea about dissolved solids in water
• More solids more conductivity.
• Measured by conductivity meter.
• Avg. value of conductivity of potable water should be
less than 2 mho/cm.
V. Specific Conductance:

25. Q. Electrical conductivity (EC) of water and total
dissolved solids (TDS) are interrelated. The value of EC
will
a) decreases with increase in TDS
b) increases with increase in TDS
c) decreases initially and then increase with increase in
TDS
d) increases initially and then decrease with increase in
TDS
V. Specific Conductance:

26. Thank You….