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8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Environmental Engineering
for
Civil Engineering
By
wwwthegateacademy com
http://www.thegateacademy.com/http://www.thegateacademy.com/http://www.thegateacademy.com/http://www.thegateacademy.com/http://www.thegateacademy.com/http://www.thegateacademy.com/http://www.thegateacademy.com/8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Syllabus Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d
Syllabus for Environmental Engineering
Quality standards, basic unit processes and operations for water treatment. Drinking waterstandards, water requirements, basic unit operations and unit processes for surface water
treatment, distribution of water. Sewage and sewerage treatment, quantity and characteristics ofwastewater 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
8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Contents Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, KeshavaKrupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P II
Assignment 1 85 86
Assignment 2 87 88
Answer Keys
Explanations
8989 90
4 Sludge Disposal 91 110
Digestion and Disposal of Primary &Secondary Sludge
91 96
Design Consideration Involved in An ActivatedSludge Plant
96 98
Effluent Disposal
Solved Examples
98 99100 103
Assignment 1 104 105
Assignment 2 106 107
Answer Keys
Explanations
108108 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
123123 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 SolidWaste)
140 142
Importance of waste transformation 143 152
Sources of hazardous waste in MSW 152
155
8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Contents Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, KeshavaKrupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P III
Solved Examples 155 156
Module Test 157 169
Test Questions 157 164
Answer Keys
Explanations
165165 - 169
Reference Book 170
8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Chapter 1 Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P 1
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) Springsii) 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) Colouriii) Taste and odour
iv) Temperaturev)
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) Jacksons 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
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Chapter 1 Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P 2
Colour: Dissolved organic material from decaying vegetation or inorganic materials may importcolour to the water.
The standard unit of color is that which is produce by one mg of platinum cobaltdissolved inone liter of distilled waterThe 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: mho/cm)
Chemical characteristics
i)
pH
ii) Acidityiii) Alkalinityiv) Hardness
v)
Chloridesvi)
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 CO 2mineral 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 withthe 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 sulphatesCarbonate and bicarbonate chlorides and nitrates.)
8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Chapter 1 Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P 3
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/LT.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 hardnessif 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 ofsulphides
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/LPermissible limit 1.0 mg/LNitrates: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 explosiveH2S Bad smellCO2Indicates biological level then it indicates presence of organic matter oxygen deficiency 58 ppmMinimum Dissolved oxygen foe survival fishes etc = 4 mg/L
8/10/2019 Gate Material - Civil Engineering, Environmental Engineering Book
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Chapter 1 Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P 4
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 survivalii) Anaerobic Bacteria Do not required dissolve O2iii)
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 coliformbacteria 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 Endos medium) thatwill 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 48hours 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 indifferent dilution combinations.
MPN value is calculation as followsFive 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 apositive Bcoli test
Water Borne Diseases and Their Control
a) Disease caused by Bacterial infectionsDisease caused byi)
Typhoid fever - salmonella typhi
ii)
Cholera - vibro choleraiii) Bacillary Dysentery shiga bacillus or Flexner - bacillus
b)
Disease cause by viral infectionsi)
Hepatitis - Hepatist viral
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Chapter 1 Environmental Engineering
THE GATE ACADEMY PVT.LTD. H.O.: #74, Keshava Krupa (third Floor), 30th
Cross, 10th
Main, Jayanagar 4th
Block, Bangalore-11
080 65700750 i f @th t d C i ht d W b th t d P 5
ii) Poliomyelitis - polio virus
c)
Disease caused by protozoal infectionsi)
Amoebic Dysentry Antoneoba histolitric germ
Quality Standard for Industrial Water Supply
Boiledferrd waterHardness 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, mustbe 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 reducingsubstances.
Source Treatment required
1.
Ground water and spring waterfairly free from contamination
2.
Ground water with chemical,
mineral and gases3. Lakes, surface water reservoir,
with less amount of pollution4.
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
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