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2. Environmental Engineering
for
Civil Engineering
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3. Syllabus Environmental Engineering
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Syllabus for Environmental Engineering
Quality standards, basic unit processes and operations for water treatment. Drinking water
standards, water requirements, basic unit operations and unit processes for surface water
treatment, distribution of water. Sewage and sewerage treatment, quantity and characteristics of
wastewater Primary, secondary and tertiary treatment of wastewater, sludge disposal, effluent
discharge standards. Domestic wastewater treatment, quantity of characteristics of domestic
wastewater, primary and secondary treatment Unit operations and unit processes of domestic
wastewater, sludge disposal.
Types of pollutants, Their sources and impacts, Air pollution meteorology, Air pollution control,
Air quality standards and limits.
Characteristics, generation, collection and transportation of solid wastes, Engineered systems
for solid waste management (reuse/ recycle, energy recovery, treatment and disposal)
Impacts of noise, Permissible limits of noise pollution, Measurement of noise and control of
noise pollution
Analysis of GATE Papers
(Environmental Engineering)
Year Percentage of marks Overall Percentage
2013 8.00
13.36%
2012 10.00
2011 11.00
2010 14.00
2009 12.00
2008 12.67
2007 14.67
2006 16.00
2005 13.33
2004 17.33
2003 18.00

4. Contents Environmental Engineering
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CONTENTS
Chapter Page No.
#1 Quality Standards of Water 1 – 12
 Municipal Water 1
 Water Quality & Standard 1 – 2
 Hardness 2 – 5
 Basic Unit Process for Water Treatment 5
 Assignment 1 6 – 7
 Assignment 2 7 – 9
 Answer Keys
 Explanations
10
10 – 12
#2 Water Supply and Its Treatment 13 – 53
 Water Quality Standards for Drinking Water 13
 Water Requirements and Demands 14 – 16
 Population Forecast 16 – 19
 Basic Unit Process/Operation for Surface
Water Treatment
19 – 20
 Screening 20
 Plain Sedimentation 20 – 23
 Electrical Properties 23 – 25
 Types of Sedimentation Tank 25 – 26
 Filtration 26 – 30
 Disinfection
 Solved Examples
30 – 37
38 – 44
 Assignment 1 45 – 47
 Assignment 2 47 – 49
 Answer Keys
 Explanations
50
50 - 53
#3 Waste Water Treatment 54 – 90
 Sewage & Sewerage Treatment 54
 Quality and Characteristic of Waste Water 54 – 72
 Types of Tracking Filters 72 – 73
 Secondary Sedimentation
 Solved Examples
73 – 74
75 – 84

5. Contents Environmental Engineering
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 Assignment 1 85 – 86
 Assignment 2 87 – 88
 Answer Keys
 Explanations
89
89 – 90
#4 Sludge Disposal 91 – 110
 Digestion and Disposal of Primary &
Secondary Sludge
91 – 96
 Design Consideration Involved in An Activated
Sludge Plant
96 – 98
 Effluent Disposal
 Solved Examples
98 – 99
100 – 103
 Assignment 1 104 – 105
 Assignment 2 106 – 107
 Answer Keys
 Explanations
108
108 – 110
#5 Domestic Waste Water Treatment 111 – 122
 Characteristic of Domestic Waste Water 111 – 112
 Treatment of Domestic Waste Water 112 – 113
 Chemical Treatment 113 – 114
 Sludge Disposal 114 – 116
 Assignment 1 117 – 118
 Assignment 2 118 – 119
 Answer Keys
 Explanations
120
120 – 122
#6 Air Pollution 123 – 138
 Introduction
 Air Pollution System
123
123 – 129
 Zone of Atmosphere 129 – 132
 Monitoring of stack emissions 132 – 137
 Filter Cleaning Method 137 – 138
#7 Solid Waste 139 –156
 Classification fo Solid Waste 139 – 140
 Physical Properties of MSW (Municipal Solid
Waste)
140 – 142
 Importance of waste transformation 143 – 152
 Sources of hazardous waste in MSW 152 – 155

6. Contents Environmental Engineering
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 Solved Examples 155 – 156
Module Test 157 – 169
 Test Questions 157 – 164
 Answer Keys
 Explanations
165
165 - 169
Reference Book 170

7. Chapter 1 Environmental Engineering
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CHAPTER 1
Quality Standards of Water
Municipal water supply: Sources
Raw water sources: The various sources of water can be classified into two categories
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 Quality and Standards
Water quality and standards are defined on the basis of analyzing the raw water on their
physical chemical and bacteriological characteristics
Physical Characteristics
i) Turbidity
ii) Colour
iii) Taste and odour
iv) Temperature
v) Specific conductance
Turbidity: If a large amount of solids are present in water it will appear turbid in appearance.
Turbidity depends upon the finess and concentration of practices present in water
It is expressed as the amount of suspended matter in mg/L or ppm
Measurement
(a) For field – Turbidity rod
(b) For Lab –
(i) Jackson’s turbidity meter
(ii) Nphelometer is used for treated water. Nephelometer can measure turbidity less
than 1 ppm
NTU – Nephlometer Turbidity unit
The IS value for drinking awter is 10 – 25 NTU

8. Chapter 1 Environmental Engineering
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Colour: Dissolved organic material from decaying vegetation or inorganic materials may import
colour to the water.
The standard unit of color 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.
Taste and Odour: 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 values.
Temperature: 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 to 120C
Specific conductance: Presence of salt can be estimated by measuring specific conductivity
(unit: μmho/cm)
Chemical characteristics
i) pH
ii) Acidity
iii) Alkalinity
iv) Hardness
v) Chlorides
vi) Iron solids
vii) Nitrates
pH: pH value denoted about the alkalinity and Baricity of the water. It is the logarithm of the
reciprocal of the hydrogen ion concentration pH = log * +
The values of PH for drinking water must liest between 6.5 to 8.5
Acidity: It is caused by the presence of uncombined CO2 mineral acids or salts of strong acids
and weak bases. It also salts of strong acids and weak bases. It also determines the measures of
capacity of water to neutralizes the measures the base.
 It is expressed as mg/L in terms of
 Desirable 200 mg/L permissible limit 600 mg/L
Hardness
It is the characteristics of water which prevents formation of lather or foam when mixed with
the soap
 It is usually caused by divalent ion of calcium and magnesium ( )
 Hardness
Temporary hardness permanent hardness
(due to presence of (Due to presence of sulphates
Carbonate and bicarbonate chlorides and nitrates.)

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Of and in water)
 The major anions associated with the hardness are sulphates, carbonates, bicarbonates,
chlorides and nitrates
 The total hardness (TH) is defined as the sum of concentration of mg and Ca ion and is
expressed in terms of in mg/L
T.H (mg|L) ×
= (mg|L) ×
T.H = (mg|L) × ( ) g ( )
 Non carbonate ions cannot be precipitated or removed by boiling add, hence it is called
permanent hardness
 Desirable limits 300mg/L as
Permissible limit 690mg/L as
 If hardness ≤ 75ppm > soft water
 If hardness lies between 75-200 => moderate hardness
if hardness > 200 => hardnes
Chlorides Content
 In the form of NaCl
 Permissible limit – 250 mg/L
 Chloride concentration is detected by titrating water with standard silver nitrate
solution using as indicator
Sulphates: Sulphates occur in water due to leaching from sulphate mineral and oxidation of
sulphides
 Sulphates desirable limit = 150 mg/L
Permissible limit = 400 mg/L
Iron: When ferric oxide comes in contact with water it converts into ferrous bicarbonate and
further it oxidieses to ferric hydroxide ppt under favorable conditions.
Desirable limit – 0.3 mg/L
Permissible limit – 1.0 mg/L
Nitrates: Nitrates in surface water occurs by leaching of fertilizers from soil during surface run-
off and nitrification of organic matter
 Desirable limit for drinking water = 45 mg/L
Permissible limit for drinking water = 100 mg/L
 Concentration of nitrates above 45 mg/L causes a diseases called as blue baby disease
Dissolved Gases
Methane – explosive
H2S – Bad smell
CO2 – Indicates biological level then it indicates presence of organic matter oxygen deficiency 5
– 8 ppm
Minimum Dissolved oxygen foe survival fishes etc = 4 mg/L

10. Chapter 1 Environmental Engineering
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BOD, COD, TOC, etc: BOD5 = Loss of oxygen (mg/L) × dilution factor BOD of safe drinking water = 0
Bacterial and Microscopic Characteristics
i) Aerobic Bacteria → Required oxygen for survival
ii) Anaerobic Bacteria → Do not required dissolve O2
iii) Facultative Bacteria → can survive with or without O2
 Through some species of bacteria a may be helpful in cleaning of water but other
pathogenic bacteria are harmful
 The presence of pathogenic bacteria can be tested by counting presence of coil Forms
ColiForms (Also called B coli)
 Coliforms are important harmless aerobic microorganism which are found residing in the
intestines of all warm blooded animals including human being
 Since these harmless organism live longer in water than the pathogenic bacteria it is
generally presumed that the water will be safe are free from pathogens if no coliform
bacteria are present in it.
Measurement of coliform
 Widely used
 Filter the water through a sterile membrane of special design porosity = 80 pore size (5
to 10 rm) and the membrane is put in contact with nutrients (M – Endo’s medium) that
will permit the growth of only coliform colonies. This process is called culturing.
 After an incubation period of 20 hrs, the coliform organs are developed into visible
colonies which can be easily counted Ecoli ferment lactose with gas formation with 48
hours incubation at 350 C. Based on this E.coli density is estimated by multiple
fermentation procedure in different test. Which consist of identification of E.coli in
different dilution combinations.
 MPN value is calculation as follows
Five 10 ml (five dilution combinations) tube is tested for E.coli and if out 5 only one given
positive test for E.coli and all other are negative
 The from the table we can find out the MNP value for one (+ve) and other (-ve), which is
equal to 2.2 in present case
Coliform
Used to measure the coliform bacteria present in water sample
“It may be defined as the reciprocal of the smallest quantity of a sample which would give a
positive B coli test”
Water Borne Diseases and Their Control
a) Disease caused by Bacterial infections
Disease caused by
i) Typhoid fever - salmonella typhi
ii) Cholera - vibro – cholera
iii) Bacillary Dysentery – shiga bacillus or Flexner - bacillus
b) Disease cause by viral infections
i) Hepatitis - Hepatist viral

11. Chapter 1 Environmental Engineering
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ii) Poliomyelitis - polio virus
c) Disease caused by protozoal infections
i) Amoebic Dysentry – Antoneoba histolitric germ
Quality Standard for Industrial Water Supply
Boiledferrd water
Hardness 1 mg/L
Pulp and paper:L water should be free from iron Mn and hardness.
Quality Standard for Municipal Water Supply
Municipal water required for domestic uses, particularly the water required for drinking, must
be colorless odourless and tasteless. It should be free turbidity and excessive toxic chemical and
bacteriological characteristics of water must be in between the desirable and permissible limit.
Basic Unit Process and Operation for Water Treatment.
Unit Process Aeration Function (Removal) colour. Odour, taste.
Screening Floating matter
Chemical methods Iron, Mangness
Softening Hardness
Sedimentation Suspended matter
Coagulation Suspended matter, a part of colloidal water
and bacteria
Filtration Remaining colloidal, dissolved matter,
bacteria
Disinfecting Pathogenic bacteria, organic and reducing
substances.
Source Treatment required
1. Ground water and spring water
fairly free from contamination
2. Ground water with chemical,
mineral and gases
3. Lakes, surface water reservoir,
with less amount of pollution
4. Other surface water such as river,
canals and impounded reservoir
with a considerable amount of
pollution
No treatment or chlorination
Aeration, coagulation (if necessary,
filtration and disinfection)
Disinfection
Complete treatment