Identification of Pollution Sources & Water Quality Analysis of Dhanmondi & Hatirjheel Lake

WATER QUALITY ANALYSIS AND ASSESMENT
OF POLLUTION SOURCES OF DHANMONDI AND
HATIRJHEEL LAKE
A thesis submitted by
Daiyan Ahmed Khan
(Student no.: 1004114)
Tariq Mehmood
Department of Civil Engineering
Bangladesh University of Engineering and Technology
Dhaka, Bangladesh
August 2016

WATER QUALITY ANALYSIS AND ASSESMENT
OF POLLUTION SOURCES OF DHANMONDI AND
HATIRJHEEL LAKE
This thesis is submitted to the Department of Civil Engineering, BUET,
Dhaka, in partial fulfillment of the requirements for the degree of
Bachelor of Science in Civil Engineering.
CE 400
PROJECT AND THESIS
Submitted by
Daiyan Ahmed Khan
Tariq Mehmood
Project Supervisor
Dr. Md. Abdul Jalil
PROFESSOR
Department of Civil Engineering
Bangladesh University of Engineering and Technology
Dhaka, Bangladesh
August 2016

i
Declaration
This is to certify that this research work has been done by the
candidates and it was not submitted elsewhere for the award of degree
of Bachelor of Science in Engineering or for any Diploma.
___________________________ ____________________________
(Supervisor) (Candidate)
Dr. Md. Abdul Jalil
Professor
Department of Civil Engineering,
BUET
Daiyan Ahmed Khan
Student no. : 1004114
____________________________
(Candidate)
Tariq Mehmood
Student no. : 1004198

ii
DEDICATED
to
Our beloved Parents who supported us all the way

iii
Acknowledgement
At first the authors acknowledge the blessings of almighty, kind, merciful, Allah.
The authors would like to express their deepest gratitude and sincere appreciation to their
supervisor Dr. Md. Abdul Jalil, Professor, Department of Civil Engineering, BUET, Dhaka
for his constant guidance, invaluable suggestions and affectionate encouragement.
The cordial support and help of the laboratory staff of CE department especially the support
of Mr. Rafiqul Islam (Mithu) and Md. Jalaluddin during experimental phase of the research
work is gratefully acknowledged.
Finally, the authors also pay their deepest homage to their family members and friends who
helped them with necessary advice and moral support during this work.

iv
Abstract
Water is fundamental to human welfare, to all socioeconomic development and for
maintaining healthy ecosystems. Because of growing population and human activities on
nature, there is scarcity of water and water is being contaminated. The non-uniform
distribution of rainfall and its intensity cause either floods or drought in some regions of
Asia almost every year. In Dhaka City, due to unplanned and excessive growth of
urbanization and industrialization, lake water utilization and quality deterioration has been
increased fast with the contribution to serious environmental degradation which ultimately
inspired us to do this assessment of water quality of two important lakes of Dhaka city.
To do so sample were collected from four different points on the basis of inlet sources over
a four-month time period, from December 2015 to March 2016 (for Dhanmondi lake) and
from April 2016 to July 2016 (for Hatirjheel lake). The assessment included whether water
quality varies among different points of the study area along with the variation of seasons.
In this study period and study sample size was limited for test due to time limitation and
was not enough to make total environmental study of the lakes.
The information harvested from the laboratory tests on the different water samples of the
Hatirjheel Lake showed the variations that comes into play along the length of the lake as
well as the variations due to the change of the seasons. Comparing the water quality of both
Dhanmondi & Hatirjheel Lakes and we found that water of Dhanmondi Lake is of better
quality and can be reused if proper treatment plant is established and contamination source
surrounding the water body is prevented. Routine research work with wide public
awareness, government participation and government regulations can save the water of
Dhaka metropolitan city and thus a safe and sound water environment can be made for
future generations.

v
Table of Contents
Declaration i
Dedicated ii
Acknowledgement iii
Abstract iv
List of Figures viii
List of Tables xi
Abbreviations xii
1 Introduction...................................................................................................... 2
1.1 General ................................................................................................................. 2
1.2 Objective .............................................................................................................. 3
1.3 Scope of the Study................................................................................................ 3
1.4 Report Synopsis.................................................................................................... 3
2 Literature Review ............................................................................................ 6
2.1 Introduction.......................................................................................................... 6
2.2 Existing geography & environmental condition of study area............................. 6
2.3 Parameters of concern .......................................................................................... 9
2.3.1 pH of Water..............................................................................................................9
2.3.2 Dissolved Oxygen..................................................................................................10
2.3.3 Turbidity ................................................................................................................10
2.3.4 Biochemical Oxygen Demand ...............................................................................11
2.3.5 Chemical Oxygen Demand....................................................................................12
2.3.6 Phosphate (𝑷𝑶𝟒 𝒂𝒔 𝑷) ..........................................................................................13
2.3.7 Nitrate (𝑵𝑶𝟑 − 𝑵) .................................................................................................13
2.3.8 Ammonia (𝑵𝑯𝟑 − 𝑵)............................................................................................14
2.4 Previous Studies................................................................................................. 15
3 Methodology................................................................................................... 17
3.1 General ............................................................................................................... 17
3.2 Sources of pollution ........................................................................................... 17

vi
3.2.1 Pollution sources of Dhanmondi Lake...................................................................17
3.2.2 Pollution sources Hatirjheel Lake..........................................................................21
3.3 Selection of sampling points .............................................................................. 24
3.4 Preparation of Sample Container ....................................................................... 25
3.5 Volume of Sample.............................................................................................. 25
3.6 Collection of Sample.......................................................................................... 26
3.7 Test Procedures .................................................................................................. 26
3.7.1 pH...........................................................................................................................26
3.7.2 Turbidity ................................................................................................................27
3.7.3 Dissolved Oxygen..................................................................................................28
3.7.4 Phosphate, Color and Ammonia ............................................................................28
3.7.5 Chemical Oxygen Demand (COD)........................................................................29
3.7.6 Biochemical Oxygen Demand (BOD) ...................................................................30
4 Test Results and Discussion.......................................................................... 34
4.1 Introduction........................................................................................................ 34
4.2 Test Results ........................................................................................................ 34
4.2.1 pH...........................................................................................................................35
4.2.2 Turbidity (NTU).....................................................................................................38
4.2.3 Ammonia (𝑵𝑯 𝟑 − 𝑵) (𝒎𝒈/ 𝑳)..............................................................................41
4.2.4 Phosphate (𝑷𝑶 𝟒 𝒂𝒔 𝑷) (𝒎𝒈 /𝑳).............................................................................44
4.2.5 Chemical Oxygen Demand (𝑪𝑶𝑫) (𝒎𝒈/L)..........................................................47
4.2.6 Biochemical Oxygen Demand (𝑩𝑶𝑫) (𝒎𝒈/L) .....................................................50
4.2.7 Color ......................................................................................................................53
4.2.8 pH...........................................................................................................................56
4.2.9 Dissolved Oxygen (DO) (mg/l)..............................................................................59
4.2.10 Color (Pt-Co) .........................................................................................................62
4.2.11 Turbidity (NTU).....................................................................................................65
4.2.12 Phosphate (mg/l) ....................................................................................................68
4.2.13 Chemical Oxygen Demand (COD) (mg/l).............................................................71
4.2.14 Ammonia (mg/l).....................................................................................................74
4.2.15 Biochemical Oxygen Demand (BOD (mg/l)..........................................................77
4.3 Discussion .......................................................................................................... 80
4.3.1 Discussion of Dhanmondi Lake.............................................................................80
4.3.2 Discussion of Hatirjheel Lake................................................................................81

vii
5 Conclusions & Recommendations................................................................ 84
5.1 Conclusion.......................................................................................................... 84
5.2 Recommendations.............................................................................................. 85
References 86

viii
List of Figures
Figure 2.1: Map of Dhanmondi Lake .................................................................................7
Figure 2.2: Map of Hatirjheel Lake .....................................................................................8
Figure 3.1: Natural Pollution of Dhanmondi Lake ............................................................17
Figure 3.2: Man Made pollution of Dhanmondi Lake.......................................................20
Figure 3.3: Natural pollution of Hatirjheel Lake ...............................................................21
Figure 3.4: Man Made pollution of Hatirjheel Lake..........................................................23
Figure 3.5: pH meter..........................................................................................................26
Figure 3.6: Measurement of turbidity using Nephelometric turbidimeter.........................27
Figure 3.7: DR LANGE Turbidimeter instrument set .......................................................27
Figure 3.8: DO meter.........................................................................................................28
Figure 3.9: DR/2010 Spectrophotometer...........................................................................28
Figure 3.10: COD reactor ..................................................................................................29
Figure 3.11: High range COD vials...................................................................................29
Figure 3.12: Bottles in which reactions involved in BOD measurement occur.................31
Figure 3.13: Magnetic titrator............................................................................................31
Figure 3.14: Carbonaceous and Nitrogenous Biochemical Oxygen Demand ...................32
Figure 4.1: pH values infront of Shimanto Sq. .................................................................35
Figure 4.2: pH values beside jahajbari...............................................................................36
Figure 4.3: pH values behind the slum ..............................................................................36
Figure 4.4: pH values at Robindroshorobor.......................................................................37
Figure 4.5: Variations of pH over time at different sampling points ................................37
Figure 4.6: Turbidity values in front of Shimanto Sq. ......................................................38
Figure 4.7: Turbidity values beside jahaj bari ...................................................................39
Figure 4.8: Turbidity values behind the slum ....................................................................39
Figure 4.9: Turbidity values at Robindroshorobor ............................................................40
Fig 4.10: Variations of Turbidity over time at different sampling points..........................40
Figure 4.11: NH3-N values infront of Shimanto Sq. .........................................................41
Fig 4.12: NH3-N values beside Jahaj Bari ........................................................................42
Figure 4.13: NH3-N values behind the slum......................................................................42

ix
Figure 4.14:NH3-N values at Robondroshorobor ..............................................................43
Figure 4.15: Variations of NH3-N over time at different sampling points .......................43
Figure 4.16: PO4 as P values infront of Shimanto Sq. ......................................................44
Figure 4.17:PO4 values as P beside jahaj bari....................................................................45
Figure 4.18:PO4 values as P behind the slum ....................................................................45
Figure 4.19: PO4 values as P at Robindroshorobor............................................................46
Figure 4.20: Variations of PO4 as P over time at different sampling points .....................46
Figure 4.21: COD values infront of Shimanto Sq. ...........................................................47
Figure 4.22: COD values beside Jahaj Bari.......................................................................48
Figure 4.23: COD values behind the slum.........................................................................48
Figure 4.24: COD values at Robindroshorobor.................................................................49
Figure 4.25: Variations of COD over time at different sampling point.............................49
Figure 4.26: BOD5 values infront of Shimanto Sq. ..........................................................50
Figure 4.27: BOD5 values beside jahaj bari ......................................................................51
Figure 4.28: BOD5 values behind the slum.......................................................................51
Figure 4.29: BOD5 values at Robindroshorobor...............................................................52
Figure 4.30: Variations of BOD5 over time at different sampling points ........................52
Figure 4.31: values of Colour infront of Shimanto Sq. .....................................................53
Figure 4.32: Values of color beside Jahaj bari...................................................................54
Figure 4.33: Values of color at behind the slum................................................................54
Figure 4.34: Values of color at Robindroshorobor............................................................55
Figure 4.35: Variations of Color over time at different sampling points...........................55
Figure 4.36: pH values at Mogbazar flyover .....................................................................56
Figure 4.37: pH values at Overflow Structure...................................................................57
Figure 4.38: pH values at Inlet of Gulshan Lake...............................................................57
Figure 4.39: pH values behind the sonargaon hotel...........................................................58
Figure 4.40: Variation of pH over time at different sampling ponits ...............................58
Figure 4.41: DO values at Mogbazar flyover ....................................................................59
Figure 4.42: DO values at Overflow Structure ..................................................................59
Figure 4.43: DO values at Inlet of Gulshan Lake ..............................................................60
Figure 4.44: DO values at behind Sonargaon hotel ...........................................................60

x
Figure 4.45: Variation of DO over time at different sampling points ..............................61
Figure 4.46: Color (Pt-Co) values at Mogbazar flyover....................................................62
Figure 4.47: Color (Pt-Co) values at overflow structure ...................................................63
Figure 4.48: Color (Pt-Co) values at Inlet of Gulshan Lake..............................................63
Figure 4.49: Color (Pt-Co) values behind Sonargaon hotel...............................................64
Figure 4.50: Variation of Color (Pt-Co) over time at different sampling points ..............64
Figure 4.51: Turbidity (NTU) values at Mogbazar flyover ...............................................65
Figure 4.52: Turbidity (NTU) values at Overflow structure..............................................66
Figure 4.53: Turbidity (NTU) values at Inlet of Gulshan Lake.........................................66
Figure 4.54: Turbidity (NTU) values at Inlet behind Sonargaon hotel..............................67
Figure 4.55: Variation of Color (Pt-Co) over time at different sampling points ..............67
Figure 4.56: Phosphate (mg/l) values at Mogbazar flyover...............................................68
Figure 4.57: Phosphate (mg/l) values at Overflow structure.............................................69
Figure 4.58: Phosphate (mg/l) values at Inlet of Gulshan Lake ........................................69
Figure 4.59: Phosphate (mg/l) values behind Sonargaon hotel .........................................70
Figure 4.60: Variation of Phosphate (mg/l) over time at different sampling points .........70
Figure 4.61: COD (mg/l) values at Mogbazar flyover.......................................................71
Figure 4.62: COD (mg/l) values at Overflow structure.....................................................72
Figure 4.63: COD (mg/l) values at Inlet of Gulshan Lake ................................................72
Figure 4.64: COD (mg/l) values behind Sonargaon hotel .................................................73
Figure 4.65: Variation of COD (mg/l) over time at different sampling points .................73
Figure 4.66: Ammonia (mg/l) values at Mogbazar flyover ...............................................74
Figure 4.67: Ammonia (mg/l) values at Overflow structure..............................................75
Figure 4.68: Ammonia (mg/l) values at Inlet of Gulshan Lake.........................................75
Figure 4.69: Ammonia (mg/l) values behind Sonargaon hotel..........................................76
Figure 4.70: Variation of Ammonia (mg/l) over time at different sampling points .........76
Figure 4.71: BOD5 (mg/l) values at Mogbazar flyover .....................................................77
Figure 4.72: BOD5 (mg/l) values at Overflow structure....................................................78
Figure 4.73: BOD5 (mg/l) values at Inlet of Gulshan Lake ...............................................78
Figure 4.74: BOD5 (mg/l) values behind Sonargaon hotel................................................79
Figure 4.75: Variation of BOD5 (mg/l) over time at different sampling points ...............79

xi
List of Tables
Table 3.1: Details of sampling points of Dhanmondi Lake...............................................24
Table 3.2: Details of sampling points of Hatirjheel Lake..................................................24
Table 3.3: Date, Time & Weather Condition of water sample collection of Dhanmondi
Lake....................................................................................................................................25
Table 3.4: Date, Time & Weather Condition of water sample collection of Hatirjheel Lake
............................................................................................................................................25
Table 4.1: pH values obtained from test samples ..............................................................35
Table 4.2: Turbidity values obtained from test samples....................................................38
Table 4.3: 𝑵𝑯 𝟑 − 𝑵 values obtained from test samples....................................................41
Table 4.4: 𝑷𝑶 𝟒 𝒂𝒔 𝑷 values obtained from test samples...................................................44
Table 4.5: 𝑪𝑶𝑫 values obtained from test samples...........................................................47
Table 4.6: 𝑩𝑶𝑫𝟓 values obtained from test samples........................................................50
Table 4.7 Color values obtained from different samples...................................................53
Table 4.8: pH values obtained from test samples ..............................................................56
Table 4.9: DO values obtained from test samples .............................................................59
Table 4.10: Color values obtained from test samples........................................................62
Table 4.11: Turbidity (NTU) values obtained from test samples ......................................65
Table 4.12: Phosphate (mg/l) values obtained from test samples......................................68
Table 4.13: COD (mg/l) values obtained from test samples..............................................71
Table 4.14: Ammonia (mg/l) values obtained from test samples......................................74
Table 4.15: BOD5 (mg/l) values obtained from test samples ............................................77

xii
Abbreviations
APHA American Public Health Association
BOD Biochemical Oxygen Demand
COD Chemical Oxygen Demand
DO Dissolved Oxygen
ECR Environment Conservation Rules
NTU Nephelometric Turbidity Units
pH Power of Hydrogen
ppm parts per million
TDS Total Dissolved Solids
TSS Total Suspended Solids
WHO World Health Organization

P a g e | 1
Chapter 1
Introduction

P a g e | 2
1 Introduction
1.1 General
Water is a unique resource because it is essential for all life and it constantly cycles between
the land and the atmosphere. The same water is also used for crop and animal production
beside it can be shared with the public and the aquatic and terrestrial ecosystems. Water
resources are of great environmental issues and studied by a wide range of specialists
including hydrologists, engineers, ecologists, geologists and geo morphologists (Kumar
and Dua, 2009). It has become an important issue for them as it affects not only human
uses but also plant and animal life. Lakes are one of the most potential water resources that
can meet the increasing demand of water throughout the Dhaka city in dry seasons.
A lake (from Latin lacus) is a terrain feature, a body of liquid on the surface of the world
that is localized to the bottom of basin and moves slowly if it moves at all. They act as
water retention basins during the Monsoon; and besides being the sources of biodiversity
of the area, they are an important part of the scenic beauty. Dhanmondi and Hatirjheel
Lakes are the part of long demand of the urban dwellers for their physical as well as mental
nourishment.
The water levels of both Dhanmondi and Hatirjheel lakes vary over time. Significant input
sources are precipitation onto the lake, runoff carried by streams and channels from the
lake’s catchment area, and artificial sources from outside the catchment area. Output
sources are evaporation from the lake, surface, and groundwater flows, and any extraction
of lake water by humans. As climate conditions and human water requirements vary, these
create fluctuations in the lake water level. Also, lakes often contain high pollution levels
relative to the surrounding landscapes and environment. It can take many forms from
industrial, agricultural, or municipal sources; a few common examples include pesticides,
herbicides, sewage, and litter. Thus there is need to assess the water quality of Dhanmondi
Hatirjheel lakes to find out the sources and solution of pollution of water.

P a g e | 3
1.2 Objective
The major objectives of the present thesis are as follows:
a) To assess overall water quality of Dhanmondi Lake and Hatirjheel Lake.
b) To study Variation of water quality of different points of sources of the lake area.
c) To identify Pollution sources (present and expected), including domestic, industrial.
d) To assess the degree of water pollution and its impacts.
e) To identify the major parameters influencing the improvements of the
environmental condition of lake.
1.3 Scope of the Study
 For effective operation of treatment facilities it is imperative to know the level of
pollution of the water bodies. This study can be helpful in this regard.
 Both the lakes cover major part of water bodies in Dhaka city. So, this study can
be helpful for any future planning concerning these areas.
 In order to assist the natural processes of groundwater recharge, maintenance of
aquatic life and ecological balance and for turning the lakes and surrounding areas
into recreational places, this study is of highest importance.
1.4 Report Synopsis
This study contains six chapters along with references. The organization of the thesis is
given below:
Chapter 1: This chapter includes introduction, objectives and scope of the study.
Chapter 2: This chapter describes literature review covering background information on
the Hatirjheel Lake area and its environmental significance, description of different water
quality parameters and previous studies of similar approaches regarding assessment of lake
water pollution.

P a g e | 4
Chapter 3: This chapter presents sampling procedure and test procedure of the water
samples collected from the study area.
Chapter 4: This chapter discusses the experimental results based on laboratory tests of
samples collected.
Chapter 5: This final chapter summarizes the major conclusions from the present study.
It also presents recommendations for future study relating Hatirjheel and Dhanmondi Lake.

P a g e | 5
Chapter 2
Literature Review

P a g e | 6
2 Literature Review
2.1 Introduction
A primary concern of people living in developing countries is that of obtaining clean
drinking water. Conservation of Freshwater resources has now become an issue of
worldwide concern because this water is one of the vital resources for treatment as drinking
water. Of these, lakes are the best "available freshwater source on the Earth's surface." Lake
water plays an important role to serve as many purposes like irrigation aquaculture and
livestock usage. Study of lakes is important for the following purposes-
 Development and implementation of lake-management plans.
 Prevention of flood and over-flow.
 Protection of present water quality.
 Restoration of former water quality.
 Watershed (land-use) planning and management.
 Wetland protection or restoration.
 Establishment of proper sewage lines.
 Lake classification and local ordinance development.
 Protection of fish and wildlife and their habitat.
The type of the area, the surrounding establishments and the general use of a lake has great
influence on its water quality. So a clear idea is essential about the area through which a
lake passes. At the same time different water quality parameters and their environmental
significance must be known. This will help to get a clear view about the water quality and
the extent of pollution.
2.2 Existing geography & environmental condition of study area
Dhanmondi Lake is situated in the middle of Dhaka City (23°43'N latitude and 90°26'E
longitude). Beginning from Jigatola (Dhanmondi Road-2) the lake extends up to Road-27
(new 16A), and bounded by the Mohammadpur-Lalmatia area in the north, Satmasjid Road

P a g e | 7
in the west, Bangladesh Rifles gate (Dhanmondi Road-2) in the south and in the east by
Kalabagan residential area. It is 3 km in length, width varies from 35 m to 100 m with a
maximum depth of 4.77 m and the total area of the water body is approximately 37.37 ha.
There is one box culvert in the lake near Sukrabad area, which is the only outlet of the lake.
The lake is under the management of several authorities looking after its various aspects.
The Dhaka City Corporation, being the principal civic body, exercises some responsibility
in its improvement. The Department of Environment looks after the aspects of proper
environment and protection of aquatic resources of the lake. In and around Dhanmondi
Lake, some renovation works were carried out from 1998 to 2001 with a view to making
the lake a pollution free recreation zone.
Figure 2.1: Map of Dhanmondi Lake
Hatirjheel is located at the centre of the Dhaka city. The place is surrounded by Tejgaon,
Gulshan, Badda, Banasree, Niketon, Maghbazar etc. It is hydraulically linked with the
Gulshan and Banani lakes. Banani Lake is linked with Hatirjheel through a canal which
also receives storm water from the Mohakhali box culvert. It has an approximate area of
1.215 𝑘𝑚2. During dry reason, the Hatirjheel Lake can hold approximately 3.06 billion

P a g e | 8
liter of water. During the rainy season, the lake can hold approximately 4.81 billion liter of
water. This makes Hatirjheel Lake the largest water body inside the capital of Bangladesh.
Figure 2.2: Map of Hatirjheel Lake

P a g e | 9
2.3 Parameters of concern
All the parameters related to this study are described below:
2.3.1 pH of Water
pH is a measure of the acidic or alkaline condition of water. It is a way of expressing the
hydrogen ion concentration or more precisely, the hydrogen ion activity. pH is defined as
follows:
𝑝𝐻 = −log[𝐻+]
Where, [𝐻+] is the concentration or activity of hydrogen ion or proton in 𝑚𝑜𝑙𝑒𝑠 𝑙𝑖𝑡𝑟𝑒 ⁄
(𝑀). The pH is usually represented by a scale ranging from 0 to 14, with 7 being neutral.
pH of less than 7 indicate acidity, whereas a pH greater than 7 indicates a base. Some
natural waters are sometimes found to be slightly alkaline due to the presence of
bicarbonate and, less often, carbonate. A lake’s pH will fluctuate somewhat each day and
from season to season in response to photosynthesis by algae and other aquatic plants,
watershed runoff, and other factors. pH may change with depth, primarily due to various
chemical reactions and a decrease in photosynthesis.
Environmental Significance
Since pH can be affected by chemicals in the water, pH is an important indicator of water
that is changing chemically. A controlled value of pH is desired in water supplies, sewage
treatment and chemical process plants. In water supply pH is important for coagulation,
disinfection, water softening and corrosion control. In biological treatment of wastewater,
pH is an important parameter, since organisms involved in treatment plants are operative
within a certain pH range.

P a g e | 10
2.3.2 Dissolved Oxygen
Dissolved Oxygen is the amount of gaseous oxygen (𝑂2) dissolved in the water. Oxygen
enters the water by direct absorption from the atmosphere, by rapid movement, or as a
waste product of plant photosynthesis. The concentration of dissolved oxygen in
unpolluted fresh water can vary greatly and is influenced by temperature, atmospheric
pressure, and salinity. For example, cold water can contain more oxygen than can warmer
water.
Dissolved oxygen (DO), the measure of gaseous oxygen in water, is necessary for good
water quality. It is essential for gilled fish and insects, and influences many different
biological and chemical processes in lakes and streams. It is the most commonly used
indicator of the general health of a surface water body. If DO in the water body goes below
4 to 5 mg/L, forms of aquatic life that can survive begin to be reduced. When anaerobic
condition exists, higher life forms are killed or driven off. Noxious condition, including
floating sludge, bubbling, odorous gases, and slimy fungus growth prevails.
2.3.3 Turbidity
Turbidity is a measure of the degree to which the water loses its transparency due to the
presence of suspended particulates. In other words, the term ‘turbid’ is applied to water
containing suspended matter that interferes with passage of light through the water or in
which visual depth is restricted. Turbidity may be caused by a wide variety of suspended
substances of various sizes ranging in size from colloidal to coarse particles, depending on
the degree of turbulence. In rivers under flood conditions, most of the turbidity will be due
to relatively coarse particles whereas in lakes and other waters existing under relatively
quiescent conditions, most of the turbidity will be due to colloidal and extremely fine
particles.
Turbidity is important for water supply engineers as turbid water is not aesthetically
acceptable to people. For filtration process, turbid water is not suitable as it causes quick

P a g e | 11
clogging of filter bed and thus requires the use of pre-treatment plant. Turbidity is also an
important parameter in disinfection process. Disinfection is usually accomplished by
means of chlorine, ozone, or chlorine dioxide. To be effective, there must be contact
between the agent and the organisms to be killed. However, in cases in which turbidity is
caused by municipal wastewater solids, many of the pathogenic organisms may be encased
in the particles and protected from the disinfectant. In addition, the suspended particles
absorb heat from the sunlight, making turbid waters become warmer, and so reducing the
concentration of oxygen in the water. The suspended particles scatter the light, thus
decreasing the photosynthetic activity of plants and algae, which contributes to lowering
the concentration even more.
2.3.4 Biochemical Oxygen Demand
When biodegradable organic matter/waste (the most common category of pollutant
affecting is released into a water body, microorganisms (especially bacteria) feed on the
wastes, breaking it down to simpler organic and inorganic substances. When this
decomposition takes place in an aerobic environment (i.e., in the presence-of oxygen), it
produces non-objectionable, stable end products (e.g., 𝐶𝑂2,4,𝑃𝑂4, and 𝑁𝑂3) and in the
process draws down the dissolved oxygen (DO) content of water.
𝑂𝑟𝑔𝑎𝑛𝑖𝑐 𝑚𝑎𝑡𝑡𝑒𝑟 + 𝑂2 = 𝐶𝑂2 + 𝐻2𝑂 + 𝑁𝑒𝑤 𝑐𝑒𝑙𝑙𝑠 + 𝑆𝑡𝑎𝑏𝑙𝑒 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠
When insufficient oxygen is available or when oxygen is exhausted by the aerobic
decomposition of wastes, then different set of microorganisms carry out the decomposition
anaerobically producing highly objectionable products including 𝐻2𝑆,3 and 𝐶𝐻4.
𝑂𝑟𝑔𝑎𝑛𝑖𝑐 𝑚𝑎𝑡𝑡𝑒𝑟 = 𝐶𝑂2 + 𝐶𝐻4 + 𝑁𝑒𝑤 𝑐𝑒𝑙𝑙𝑠 + 𝑈𝑛𝑠𝑡𝑎𝑏𝑙𝑒 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠
The amount of oxygen required by micro-organisms to oxidize organic wastes aerobically
is called biochemical oxygen demand (BOD). BOD may have various units, but most often
it is expressed in mg of oxygen required per liter of water/wastewater (mg/L). The total
amount of oxygen that will be required for biodegradation is an important measure of the
impact that a given waste stream would have on the receiving water body.

P a g e | 12
The total amount of oxygen that will be required for bio-degradation of organic wastes is
an important measure of the impact that a given waste stream would have on the receiving
water body. Dissolved oxygen is the most commonly used indictor of the general health of
a surface water body. If DO goes below 4 to 5 mg/L (due to decomposition of organic
wastes), forms of life that can survive begin to be reduced. When anaerobic condition
exists, higher forms are killed or driven off and noxious condition, including floating
sludge, bubbling, odorous gases, and slimy fungus growth prevails.
2.3.5 Chemical Oxygen Demand
The chemical oxygen demand (COD), test is widely used as a means of measuring the
organic strength of domestic and industrial wastes. This test allows measurement of a waste
in terms of the total quantity of oxygen required for oxidation to carbon dioxide and water.
COD test is based on the fact that all organic compounds, with a few exceptions, can be
oxidized by the action of strong oxidizing agents under acid conditions. The major
advantage of COD test is the short time required for evaluation. The determination can be
made in about 3 hours rather than 5-days required for the measurement of BOD. For this
reason, it is used as a substitute for the BOD test in many instances.
COD gives a measure of organic strength of domestic and industrial wastes. The higher
value of COD indicates the presence of undesirable organic matter, demanding
investigation of the cause before the water is pronounced potable. Measurement of COD
in municipal and industrial wastewater treatment plants indicates the efficiency of the
treatment process. COD has further applications in power plant operations, chemical
manufacturing, commercial laundries, pulp & paper mills, environmental studies and
general education.

P a g e | 13
2.3.6 Phosphate (𝑷𝑶𝟒 𝒂𝒔 𝑷)
Phosphates exist in three forms: orthophosphate, metaphosphate (or polyphosphate) and
organically bound phosphate each compound contains phosphorous in a different chemical
arrangement. These forms of phosphate occur in living and decaying plant and animal
remains, as free ions or weakly chemically bounded in aqueous systems, chemically
bonded to sediments and soils, or as mineralized compounds in soil, rocks, and sediments.
Phosphates enter waterways from human and animal waste, phosphorus rich bedrock,
laundry, cleaning, industrial effluents, and fertilizer runoff. These phosphates become
detrimental when they over fertilize aquatic plants and cause stepped up eutrophication.
Phosphate will stimulate the growth of plankton and aquatic plants which provide food for
larger organisms, including zooplankton, fish, humans, and other mammals. Plankton
represents the base of the food chain. Initially, this increased productivity will cause an
increase in the fish population and overall biological diversity of the system. But as the
phosphate loading continues and there is a build-up of phosphate in the lake or surface
water ecosystem, the aging process of lake or surface water ecosystem will be accelerated.
The overproduction of lake or water body can lead to an imbalance in the nutrient and
material cycling process. If too much phosphate is present in the water the algae and weeds
will grow rapidly, may choke the waterway, and use up large amounts of precious oxygen
(in the absence of photosynthesis and as the algae and plants die and are consumed by
aerobic bacteria.) The result may be the death of many fish and aquatic organisms.
2.3.7 Nitrate (𝑵𝑶𝟑 − 𝑵)
Nitrates are widely present in substantial quantities in soil, in most waters, and in plants,
including vegetables. Fertilizer use, decayed vegetable and animal matter, domestic
effluents, sewage sludge disposal on land, industrial discharges all contribute to nitrate ion
in water sources.

P a g e | 14
Nitrate is toxic when present in excessive amounts in water and may cause
‘methamoglobinaemia’ in infants. Certain forms of cancer might be associated with very
high concentrations. No diseases have definitely been proven to be caused by water
containing less than 10 mg/L Nitrate-N. Nitrogen is one of the nutrients essential for the
growth of algae.
2.3.8 Ammonia (𝑵𝑯𝟑 − 𝑵)
Ammonia is one of several forms of nitrogen that exist in aquatic environments. Unlike
other forms of nitrogen, which can cause nutrient over-enrichment of a water body at
elevated concentrations and indirect effects on aquatic life, ammonia causes direct toxic
effects on aquatic life. It is a colorless gas with a strong pungent odor. Ammonia will react
with water to form a weak base. The term ammonia refers to two chemical species which
are in equilibrium in water (𝑁𝐻3, un-ionized and 𝑁𝐻4 +, ionized). Tests for ammonia
usually measure total ammonia (𝑁𝐻3 plus 𝑁𝐻4 +). The toxicity to ammonia is primarily
attributable to the un-ionized form (𝑁𝐻3), as opposed to the ionized form (𝑁𝐻4 +). In
general, more 𝑁𝐻3 and greater toxicity exist at higher pH. When dissolved in water, normal
ammonia (𝑁𝐻3) reacts to form an ionized species called ammonium (𝑁𝐻4 +)
𝑁𝐻3 + 𝐻2𝑂 = 𝑁𝐻4 + + 𝑂𝐻−
This is a shorthand way of saying that one molecule of ammonia reacts with one molecule
of water to form one ammonium ion and a hydroxyl ion.
Ammonia can enter the aquatic environment via direct means such as municipal effluent
discharges and the excretion of nitrogenous wastes from animals, and indirect means such
as nitrogen fixation, air deposition, and runoff from agricultural lands. When ammonia is
present in water at high enough levels, it is difficult for aquatic organisms to sufficiently
excrete the toxicant, leading to toxic buildup in internal tissues and blood, and potentially
death. Environmental factors, such as pH and temperature, can affect ammonia toxicity to
aquatic animals.

P a g e | 15
2.4 Previous Studies
As lake pollution is a common problem in Dhaka city, similar works were done in near
past. Some core findings are-
 An investigation on water quality parameters from Ramna, Crescent and Hatirjheel
Lakes was performed by M. S. Islam, M. Rehnuma, S. S. Tithi, M. H. Kabir and
L. Sarkar in 2015 which shows lower concentration of DO in all three lakes. It
also shows that the rain and storm water runoff, lack of awareness of people were
responsible for the pollution of those lakes.
 Md. Shahrior Alam conducted an assessment of water quality of Hatirjheel Lake
in 2014. He mainly focused on the lake’s water quality as drinking source. Most of
the water quality parameters he tested deviated from the standard value according
to ECR ’97.
 A study focused on water quality monitoring and pollution sources identification
of Gulshan Lake by Mafruha Ahmed in 2013 shows fluctuations in chemical
composition of lake water both spatially and temporally. The Lake water has been
characterized by very low DO (mostly below 5 mg/l) & the high 𝐵𝑂𝐷5 (up to 101.0
mg/l) indicated significant organic pollution. Among the other tested parameters-
Color, TDS, Turbidity and TSS showed the most significant seasonal variation due
to the influence of rain and storm runoff. It was observed that the concentration of
Color and TDS increased in dry season and concentration of TSS and Turbidity
increased during the wet season.
 Md. Ibrahim Sabit performed an evaluation of water quality and pollution sources
of Gulshan Lake in 2011. He found the major wastewater/ storm water outfalls
contributing to the pollution of Gulshan Lake were- storm sewer pipes, open
channels, box culverts, and small private outfalls. Relatively high concentrations of
Cadmium and Lead have been found in the lake sediments. Very high oxygen
demand (pSOD) in the lake sediments was found which he doubted for persistent
low DO of Lake water throughout the year. He also said that, the poor water quality
of Gulshan Lake was also contributed to the pollution of Hatirjheel Lake.

P a g e | 16
Chapter 3
METHODOLOGY

P a g e | 17
3 Methodology
3.1 General
Determination of the water quality parameters are necessary for the examination of the
water and to determine the quality of water. To assess the overall quality of lake water the
water samples should be taken from different points representing the whole water body. In
case of Hatirjheel and Dhanmondi Lake four sampling points were chosen for the water
sample collection based on the sources of pollution of both the lakes. Further, laboratory
tests were performed to determine the water quality parameters.
3.2 Sources of pollution
Reconnaissance of both the lakes was conducted and the pollution sources were identified.
3.2.1 Pollution sources of Dhanmondi Lake
3.2.1(A) Natural pollution
Figure Type of Pollution
Surface Runoff
By soluble Organisms &
microorganisms
Figure 3.1: Natural Pollution of Dhanmondi Lake

P a g e | 18
3.2.1 (B) Man Made pollution
Figure Type of pollution
Temporarily used solid
waste landfill
Paper used for sitting places
Drainage water mixing with
lake

P a g e | 19
Due to super structures
spreading off pollution
Manhole linkage
Washing and Bathing in the
water

P a g e | 20
Human Excreta
Excessive food wastage
gets mixed with Lake
water
Formation of slum near
embankment
Figure 3.2: Man Made pollution of Dhanmondi Lake

P a g e | 21
3.2.2 Pollution sources Hatirjheel Lake
3.2.2 (A) Natural Pollution
Figure Type of Pollution
Surface Runoff
Algal Bloom
Figure 3.3: Natural pollution of Hatirjheel Lake

P a g e | 22
3.2.2 (B) Man Made Pollution
Storm Sewer
(Major outfalls discharging
into Hatirjheel cover a
catchment area of about 30
km2
of Dhaka city)
Pollution from ongoing
construction projects
Underground Sewer

P a g e | 23
Open sluice gate carrying
sewage
solid waste landfill
Formation of slum near
embankment
Figure 3.4: Man Made pollution of Hatirjheel Lake

P a g e | 24
3.3 Selection of sampling points
Sampling points were chosen based on the pollution sources as discussed in the above
article. Samples were collected nearly one meter from the bank of the lake and at a
minimum depth of 1 feet from the water surface. Surface scum was avoided and samples
were collected with sufficient distance downstream from the source of pollution. The
details of the sampling points for both the lakes are given below.
Table 3.1: Details of sampling points of Dhanmondi Lake
Location ID
Coordinates of sampling
location
Remarks
1
23°44'19.23"N
90°22'34.6"E
Infront of shimanto square
2
23°44'30"N
90°22'37.8"E
Beside jahaj bari
3
23°44'36.6"N
90°22'42.7"E
Behind the slum
4
23°44'42.7"N
90°22'38.6"E
Robindroshorobor
Table 3.2: Details of sampling points of Hatirjheel Lake
Location ID
Coordinates of sampling
location
Remarks
1
23°45'9.63'' N
90°24'6.21"E
Mogbazar flyover
2
23°46'6.9"N
90°25'19.7"E
Overflow structure
3
23°46'20.6"N
90°25'3.1"E
Inlet of Gulshan lake
4
23°44'55.7"N
90°23'43.9"E
Behind Sonargaon Hotel

P a g e | 25
Table 3.3: Date, Time & Weather Condition of water sample collection of
Dhanmondi Lake
Sampling ID Date of Collection Time of Collection
Weather
Condition
First sampling 5th
December 2015 7:00 - 10:00 AM 23/22º C – Passing
clouds
Second sampling 23rd
February 2016 8:00 - 9:30 AM 31/30º C - Rain
Third sampling 27th
March 2016 7:30 - 9:00 AM 32/32º C - Haze
Fourth sampling 11th
May 2016 9:00 - 10:00 AM 34/28º C – Light
rain
Table 3.4: Date, Time & Weather Condition of water sample collection of
Hatirjheel Lake
Sampling ID Date of Collection Time of Collection
Weather
Condition
First sampling 30th
April 2016 9:00 - 11:30 AM 37/34º C - Fog
Second sampling 24th
May 2016 8:00 - 10:00 AM 32/28º C - Overcast
Third sampling 29th
June 2016 7:30 - 9:00 AM 30/29º C – Passing
clouds
Fourth sampling 26th
July 2016 8:00 - 9:30 AM 29/26º C –
Scattered Showers
3.4 Preparation of Sample Container
Plastic bottles were used for sample collection. They were first cleaned with tap water and
detergent, then with distilled water.
3.5 Volume of Sample
Each of the bottles were completely filled with representative sample water from the
sampling points.

P a g e | 26
3.6 Collection of Sample
Every bottle was rinsed with the water prior to sampling before taking the sample. It was
carefully noticed that air bubbles did not enter into the bottle. Samples were collected
nearly 1 ft. deep into the surface and 1 meter away from the bank.
3.7 Test Procedures
All the physico-chemical parameters were analyzed at Environmental Engineering
Laboratory at BUET according to the standard procedures (APHA, 1998).
3.7.1 pH
Figure 3.5: pH meter
Measurement of pH was carried out by electrochemical method using a 𝐻+-sensitive pH
probe/meter. It is more precise method than using pH indicator paper. Before measuring
pH, the pH meter was calibrated using some buffer solutions of known pH value.

P a g e | 27
3.7.2 Turbidity
Figure 3.6: Measurement of turbidity using Nephelometric turbidimeter
Figure 3.7: DR LANGE Turbidimeter instrument set
Turbidity was measured in Nephelometric Turbidity Units (NTU) by Nephelometry
Turbidimeter (DR LANGE Turbidimeter instrument set). In this method, a light source
illuminates the sample and one or more photoelectric detectors are used with a readout
device to indicate the intensity of scattered preparations of formazin polymer or styrene
divinylbenzene as standard reference material.

P a g e | 28
3.7.3 Dissolved Oxygen
Figure 3.8: DO meter
Dissolved Oxygen was measured by digital DO meter with electrochemical sensor. It is a
direct measurement method.
3.7.4 Phosphate, Color and Ammonia
Figure 3.9: DR/2010 Spectrophotometer

P a g e | 29
The measurement of Phosphate (𝑃𝑂4 𝑎𝑠 𝑃), Color (Pt-Co) and Ammonia (𝑁𝐻3−𝑁) were
conducted by HACH DR/2010 Spectrophotometer using HACH reagents.
3.7.5 Chemical Oxygen Demand (COD)
Figure 3.10: COD reactor
Figure 3.11: High range COD vials
Chemical Oxygen Demand was also measured by DR/2010 Spectrophotometer but before
that the samples were first heated with High Range COD vials by COD reactor for 2 hours.
The chemical oxygen demand (COD) test allows measurement of oxygen demand of the
water in terms of the total quantity of oxygen required for oxidation of the waste to carbon
dioxide and water. The test is based on the fact that all organic compounds, with a few

P a g e | 30
exceptions, can be oxidized by the action of strong oxidizing agents under acidic
conditions.
𝑂𝑟𝑔𝑎𝑛𝑖𝑐 𝑚𝑎𝑡𝑡𝑒𝑟+𝑂𝑥𝑖𝑑𝑖𝑧𝑖𝑛𝑔 𝑎𝑔𝑒𝑛𝑡=𝐶𝑂2+𝐻2𝑂
The reaction involves conversion of organic matter to carbon dioxide and water regardless
of the biological assimilability of the substance. As a result, COD values are greater than
BOD values, especially when biologically resistant organic forms are present.
Thus one of the chief limitations of COD test is its inability to differentiate between
biodegradable and non-biodegradable organic matter. In addition, it does not provide any
evidence of the rate at which the biologically active material would be stabilized under
conditions that exist in nature.
The major advantage of COD test is the short time required for evaluation. The
determination can be made in about 3 hours rather than the 5-days required for the
measurement of BOD. For this reason, it is used as a substitute for the BOD test in many
instances.
3.7.6 Biochemical Oxygen Demand (BOD)
Biochemical Oxygen Demand for 5-days (𝐵𝑂𝐷5) is measured through DO determination
by 𝑊𝑖𝑛𝑘𝑙𝑒𝑟 𝑀𝑒𝑡ℎ𝑜𝑑. The reactions involved in the various steps are presented below:
Manganous sulphate reacts with potassium hydroxide in the alkaline potassium iodide
solution to produce a white precipitate of manganous hydroxide.
𝑀𝑛𝑆𝑂4+2𝐾𝑂𝐻=(𝑂𝐻)2↓+𝐾2 𝑆𝑂4
If the white precipitate is obtained, there was no dissolved oxygen in the sample and there
is no need to proceed further. A brown precipitate shows that oxygen is present and reacted
with the manganous hydroxide and forms manganic basic oxide.
2(𝑂𝐻)2+𝑂2=2𝑀𝑛𝑂(𝑂𝐻)2↓
Upon the addition of (sulphuric) acid, this precipitate is dissolved, forming manganic
sulphate:
(𝑂𝐻)2+2𝐻2 𝑆𝑂4=𝑀𝑛(𝑆𝑂4)2+3𝐻2 𝑂
This compound immediately reacts with potassium iodide, liberating iodine and resulting
in the typical iodine (blue) coloration of the water.
(𝑆𝑂4)2+2𝐾𝐼=𝑀𝑛𝑆𝑂4+𝐾2 𝑆𝑂4+𝐼2

P a g e | 31
Figure 3.12: Bottles in which reactions involved in BOD measurement occur
Figure 3.13: Magnetic titrator

P a g e | 32
The quantity of iodine liberated by these reactions is equivalent to the quantity of oxygen
present in the sample. The quantity of iodine is determined by titrating a portion of the
solution with a standard solution of sodium thiosulphate solution. The end point of titration
is indicated by the disappearance of blue color produced by the reaction between iodine
and starch (which is added as an indicator in the titration).
2𝑁𝑎2 𝑆2 𝑂3+𝐼2=𝑁𝑎2 𝑆4 𝑂6+2𝑁𝑎𝐼
Dissolved Oxygen (DO) is measured in this method for the first day and for the fifth day
and 𝐵𝑂𝐷5 is determined from their difference.
𝐵𝑂𝐷5=𝐷𝑂𝑖−𝐷𝑂 𝑓
Figure 3.14: Illustration of Carbonaceous and Nitrogenous Biochemical Oxygen Demand
BOD is determined for five days because initially only the carbonaceous biochemical
oxygen demand (CBOD) exerts. But nitrogenous biochemical oxygen demand (NBOD)
does not begin to exert itself for at least 5 to 8 days, so most 5-day BOD tests are not
affected by the nitrification process.

P a g e | 33
Chapter 4
TEST RESULTS AND
DISCUSSION

P a g e | 34
4 Test Results and Discussion
4.1 Introduction
Clean waters are used to drink, grow crops for food, operate factories, and for swimming,
surfing, fishing and sailing. Water is vitally important to every aspect of our lives.
Monitoring the quality of surface water will help protect our waterways from pollution.
Farmers can use the information to help better manage their land and crops. Our local, state
and national governments use monitoring information to help control pollution levels. We
can use this information to understand exactly how we impact our water supply and to help
us understand the important role we all play in water conservation.
4.2 Test Results
As discussed in the previous chapter, a test procedure was conducted for four samples
collected each time at four locations for both Dhanmondi and Hatirjheel Lake. The first,
second, third and fourth batches of water collection of Dhanmondi Lake were for
December of 2015 and January, February, March of 2016 respectively. Similarly samples
were collected in April, May, June and July of 2016 for Hatirjheel Lake.
Test Results of Dhanmondi and Hatirjheel Lake are given below.

P a g e | 35
Test Results of Dhanmondi Lake
4.2.1 pH
Table 4.1: pH values obtained from test samples
Sample First Second Third Fourth
1 7.19 6.8 6.72 6.9
2 7.41 7.1 7.05 6.7
3 7.14 6.9 6.67 6.8
4 7.02 7 6.93 6.9
For the first sampling point (In front of Shimanto Sq.),
Figure 4.1: pH values infront of Shimanto Sq.
6
6.5
7
7.5
8
December January February March
pH
Month

P a g e | 36
For the second sampling point (Beside Jahaj Bari),
Figure 4.2: pH values beside jahajbari
For the third sampling point (Behind the slum),
Figure 4.3: pH values behind the slum
6
6.5
7
7.5
8
pH
month
6
6.5
7
7.5
8
pH
month

P a g e | 37
For the fourth sampling point (At Robindroshorobor),
Figure 4.4: pH values at Robindroshorobor
The seasonal variation of pH can be represented as below:
Figure 4.5: Variations of pH over time at different sampling points
6
6.5
7
7.5
8
pH
month
6.5
6.6
6.7
6.8
6.9
7
7.1
7.2
7.3
7.4
7.5
1 2 3 4
pH
Sampling points

P a g e | 38
4.2.2 Turbidity (NTU)
Table 4.2: Turbidity values obtained from test samples
1 2.59 4.69 5 3.85
2 7.92 6.04 8.02 4.32
3 4.17 3.96 3.62 4.58
4 9.58 4.3 3 5.05
For the first sampling point (In front of Shimanto Sq.)
Figure 4.6: Turbidity values in front of Shimanto Sq
0
2
4
6
8
10
Turbidity(NTU)
Month

P a g e | 39
For the second sampling point (Beside Jahaj Bari)
Figure 4.7: Turbidity values beside jahaj bari
For the third sampling point (Behind the slum)
Figure 4.8: Turbidity values behind the slum
0
2
4
6
8
10
Turbidity(NTU)
Month
0
2
4
6
8
10
Turbidity(NTU)
Month

P a g e | 40
For the fourth sampling point (At Robindroshorobor)
Figure 4.9: Turbidity values at Robindroshorobor
The seasonal variation of Turbidity can be represented as below:
Fig 4.10: Variations of Turbidity over time at different sampling points
0
2
4
6
8
10
Turbidity(NTU)
Month
0
3
6
9
12
1 2 3 4
Turbidity(NTU)
sampling point

P a g e | 41
4.2.3 Ammonia (𝑵𝑯 𝟑 − 𝑵) (𝒎𝒈/ 𝑳)
Table 4.3: 𝑵𝑯 𝟑 − 𝑵 values obtained from test samples
1 10.37 15.5 11.25 0.5
2 10.5 16.75 14.4 1
3 11 18.6 15 0.625
4 13.6 18.25 16.5 0.375
Figure 4.11: NH3-N values infront of Shimanto Sq.
0
5
10
15
20
Ammonia(NH3-N)(mg/L)
Month

P a g e | 42
For the second sampling point (Beside Jahaj Bari),
Fig 4.12: NH3-N values beside Jahaj Bari
For the third sampling point (Behind the slum),
Figure 4.13: NH3-N values behind the slum
0
5
10
15
20
25
Month
0
5
10
15
20
25
Month

P a g e | 43
Figure 4.14:NH3-N values at Robondroshorobor
The seasonal variation of Ammonia can be represented as below:
Figure 4.15: Variations of NH3-N over time at different sampling points
0
5
10
15
20
25
Month
0
2
4
6
8
10
12
14
16
18
20
1 2 3 4
Sampling Point

P a g e | 44
4.2.4 Phosphate (𝑷𝑶 𝟒 𝒂𝒔 𝑷) (𝒎𝒈 /𝑳)
Table 4.4: 𝑷𝑶 𝟒 𝒂𝒔 𝑷 values obtained from test samples
Sample First Second third fourth
1 0.06 0.05 0.06 0.04
2 0.21 0.1 0.7 0.08
3 0.07 0.06 0.04 0.09
4 0.07 0.4 0.05 0.01
Figure 4.16: PO4 as P values infront of Shimanto Sq
0
0.02
0.04
0.06
0.08
0.1
December January Februay March
Phosphate(PO4asP)(mg/L)
Month

P a g e | 45
Figure 4.17:PO4 values as P beside jahaj bari
Figure 4.18:PO4 values as P behind the slum
0
0.2
0.4
0.6
0.8
1
Month
0
0.02
0.04
0.06
0.08
0.1
december January February March
Month

P a g e | 46
Figure 4.19: PO4 values as P at Robindroshorobor
The seasonal variation of Phosphate can be represented as below:
Figure 4.20: Variations of PO4 as P over time at different sampling points
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Month
0
0.2
0.4
0.6
0.8
1
1 2 3 4
Sampling point

P a g e | 47
4.2.5 Chemical Oxygen Demand (𝑪𝑶𝑫) (𝒎𝒈/L)
Table 4.5: 𝑪𝑶𝑫 values obtained from test samples
Figure 4.21: COD values infront of Shimanto Sq.
0
10
20
30
40
50
60
COD(mg/L)
Month
1 5 15 11 17
2 7 20 14 10
3 12 13 12 46
4 55 24 35 31

P a g e | 48
Figure 4.22: COD values beside Jahaj Bari
Figure 4.23: COD values behind the slum
0
10
20
30
40
50
60
COD(mg/L)
Month
0
5
10
15
20
25
30
35
40
45
50
COD(mg/L)
Month

P a g e | 49
Figure 4.24: COD values at Robindroshorobor
The seasonal variation of COD can be represented as below:
Figure 4.25: Variations of COD over time at different sampling point
0
10
20
30
40
50
60
COD(mg/L)
Month
0
10
20
30
40
50
60
1 2 3 4
COD(mg/L)
Sampling point

P a g e | 50
4.2.6 Biochemical Oxygen Demand (𝑩𝑶𝑫) (𝒎𝒈/L)
Table 4.6: 𝑩𝑶𝑫𝟓 values obtained from test samples
1 4 2.5 1 3.9
2 10 0.6 0.6 1.5
3 6 5.3 3.52 6.3
4 2 3.3 5.4 1.9
Figure 4.26: BOD5 values infront of Shimanto Sq.
0
2
4
6
8
10
12
14
BOD5(mg/L)
Month

P a g e | 51
Figure 4.27: BOD5 values beside jahaj bari
Figure 4.28: BOD5 values behind the slum
0
2
4
6
8
10
12
14
BOD5(mg/L)
Month
0
2
4
6
8
10
12
14
BOD5(mg/L)
Month

P a g e | 52
Figure 4.29: BOD5 values at Robindroshorobor
The seasonal variation of BOD5 can be represented as below:
Figure 4.30: Variations of BOD5 over time at different sampling points
0
2
4
6
8
10
12
14
BOD5(mg/L)
Month
0
2
4
6
8
10
12
14
1 2 3 4
BOD5(mg/L)
Sampling point

P a g e | 53
4.2.7 Color
Table 4.7 Color values obtained from different samples
1 21 40 32 10
2 32 38 35 15
3 28 37 39 12
4 48 39 43 5
Figure 4.31: values of Colour infront of Shimanto Sq.
0
10
20
30
40
50
Colour(PtCO)
Month

P a g e | 54
Figure 4.32: Values of color beside Jahaj bari
Figure 4.33: Values of color at behind the slum
0
10
20
30
40
50
Colour(PtCO)
Month
0
10
20
30
40
50
Colour(PtCO)
Month

P a g e | 55
Figure 4.34: Values of color at Robindroshorobor
The seasonal variation of color can be represented as below:
Figure 4.35: Variations of Color over time at different sampling points
0
10
20
30
40
50
Colour(PtCO)
Month
0
10
20
30
40
50
60
1 2 3 4
Colour(PtCO)
Sampling point

P a g e | 56
4.2.8 pH
Table 4.8: pH values obtained from test samples
1 7.7 7.1 6.9 6.6
2 7.6 7.3 7.0 6.8
3 7.6 7.2 6.7 6.7
4 7.5 7.4 6.7 6.6
For the first sampling point (Mogbazar Flyover)
Figure 4.36: pH values at Mogbazar flyover
6
6.5
7
7.5
8
8.5
April May June July
pH
Month

P a g e | 57
For the second sampling point (Overflow Structure)
Figure 4.37: pH values at Overflow Structure
For the third sampling point (Inlet of Gulshan lake)
Figure 4.38: pH values at Inlet of Gulshan Lake
6
6.5
7
7.5
8
8.5
April May June July
pH
Month
6
6.5
7
7.5
8
8.5
April May June July
pH
Month

P a g e | 58
For the fourth sampling point (Behind Sonargaon Hotel)
Figure 4.39: pH values behind the sonargaon hotel
The Seasonal Variation of the pH can be represented as below:
Figure 4.40: Variation of pH over time at different sampling ponits
6
6.5
7
7.5
8
8.5
April May June July
pH
Month
6
6.5
7
7.5
8
8.5
1 2 3 4
DO(mg/l)
Sampling Point
April May June July

P a g e | 59
4.2.9 Dissolved Oxygen (DO) (mg/l)
Table 4.9: DO values obtained from test samples
1 8.62 9.3 11.2 12.5
2 9.2 9.67 10.7 11.2
3 9.73 9.83 10.5 11.7
4 6.6 9.25 9.1 12.6
Figure 4.41: DO values at Mogbazar flyover
For the second sampling point (Overflow Structure)
Figure 4.42: DO values at Overflow Structure
6
7
8
9
10
11
12
13
April May June July
DO(mg/l)
Month
6
7
8
9
10
11
12
13
April May June July
DO(mg/l)
Month

P a g e | 60
For the third sampling point (Inlet of Gulshan Lake)
Figure 4.43: DO values at Inlet of Gulshan Lake
For the fourth sampling point (Behind Sonargaon Hotel)
Figure 4.44: DO values at behind Sonargaon hotel
6
7
8
9
10
11
12
13
April May June July
DO(mg/l)
Month
6
7
8
9
10
11
12
13
April May June July
DO(mg/l)
Month

P a g e | 61
The Seasonal Variation of the DO can be represented as below:
Figure 4.45: Variation of DO over time at different sampling points
6
7
8
9
10
11
12
13
1 2 3 4
DO(mg/l)
Sampling Point
April May June July

P a g e | 62
4.2.10 Color (Pt-Co)
Table 4.10: Color values obtained from test samples
1 78 56 42 61
2 75 48 36 53
3 180 85 51 84
4 91 63 39 76
Figure 4.46: Color (Pt-Co) values at Mogbazar flyover
0
20
40
60
80
100
120
140
160
180
200
April May June July
Color(Pt-Co)
Month

P a g e | 63
For the Second sampling point (Overflow Structure)
Figure 4.47: Color (Pt-Co) values at overflow structure
For the Third sampling point (Inlet of Gulshan Lake)
Figure 4.48: Color (Pt-Co) values at Inlet of Gulshan Lake
0
20
40
60
80
100
120
140
160
180
200
April May June July
Color(Pt-Co)
Month
0
20
40
60
80
100
120
140
160
180
200
April May June July
Color(Pt-Co)
Month

P a g e | 64
For the Fourth sampling point (Behind Sonargaon hotel)
Figure 4.49: Color (Pt-Co) values behind Sonargaon hotel
The Seasonal Variation of the Color (Pt-Co) can be represented as below:
Figure 4.50: Variation of Color (Pt-Co) over time at different sampling points
0
20
40
60
80
100
120
140
160
180
200
April May June July
Color(Pt-Co)
Month
0
20
40
60
80
100
120
140
160
180
200
1 2 3 4
Color(Pt-Co)
Sampling Point
April May June July

P a g e | 65
4.2.11 Turbidity (NTU)
Table 4.11: Turbidity (NTU) values obtained from test samples
1 28.3 19.5 14.5 10.5
2 37.3 26.1 18.1 16.1
3 89 66.6 61.8 55.6
4 22.9 21.2 23.3 24.2
Figure 4.51: Turbidity (NTU) values at Mogbazar flyover
0
10
20
30
40
50
60
70
80
90
April May June July
Turbidity(NTU)
Month

P a g e | 66
Figure 4.52: Turbidity (NTU) values at Overflow structure
Figure 4.53: Turbidity (NTU) values at Inlet of Gulshan Lake
0
10
20
30
40
50
60
70
80
90
April May June July
Turbidity(NTU)
Month
0
10
20
30
40
50
60
70
80
90
April May June July
Turbidity(NTU)
Month

P a g e | 67
For the Fourth sampling point (Behind Sonargaon Hotel)
Figure 4.54: Turbidity (NTU) values at Inlet behind Sonargaon hotel
The Seasonal Variation of the Turbidity (NTU) can be represented as below:
Figure 4.55: Variation of Color (Pt-Co) over time at different sampling points
0
10
20
30
40
50
60
70
80
90
April May June July
Turbidity(NTU)
Month
0
10
20
30
40
50
60
70
80
90
1 2 3 4
Turbidity(NTU)
Sampling Point
April May June July

P a g e | 68
4.2.12 Phosphate (mg/l)
Table 4.12: Phosphate (mg/l) values obtained from test samples
1 0.01 0.15 0.35 0.50
2 0.02 0.22 0.28 0.22
3 0.01 0.10 0.33 0.40
4 0.011 0.11 0.41 0.50
Figure 4.56: Phosphate (mg/l) values at Mogbazar flyover
0
0.1
0.2
0.3
0.4
0.5
0.6
April May June July
Phosphate(mg/l)
Month

P a g e | 69
Figure 4.57: Phosphate (mg/l) values at Overflow structure
Figure 4.58: Phosphate (mg/l) values at Inlet of Gulshan Lake
0
0.1
0.2
0.3
0.4
0.5
0.6
April May June July
Phosphate(mg/l)
Month
0
0.1
0.2
0.3
0.4
0.5
0.6
April May June July
Phosphate(mg/l)
Month

P a g e | 70
Figure 4.59: Phosphate (mg/l) values behind Sonargaon hotel
The Seasonal Variation of the Phosphate (mg/l) can be represented as below:
Figure 4.60: Variation of Phosphate (mg/l) over time at different sampling points
0
0.1
0.2
0.3
0.4
0.5
0.6
April May June July
Phosphate(mg/l)
Month
0
0.1
0.2
0.3
0.4
0.5
0.6
1 2 3 4
Phosphate(mg/l)
Sampling Point
April May June July

P a g e | 71
4.2.13 Chemical Oxygen Demand (COD) (mg/l)
Table 4.13: COD (mg/l) values obtained from test samples
1 74 100 91.5 132
2 72 85.5 65.5 59
3 85 102 97 120
4 53 80.5 72.4 108
Figure 4.61: COD (mg/l) values at Mogbazar flyover
0
20
40
60
80
100
120
140
160
April May June July
COD(mg/l)
Month

P a g e | 72
Figure 4.62: COD (mg/l) values at Overflow structure
Figure 4.63: COD (mg/l) values at Inlet of Gulshan Lake
0
20
40
60
80
100
120
140
160
April May June July
COD(mg/l)
Month
0
20
40
60
80
100
120
140
160
April May June July
COD(mg/l)
Month

P a g e | 73
Figure 4.64: COD (mg/l) values behind Sonargaon hotel
The Seasonal Variation of the COD (mg/l) can be represented as below:
Figure 4.65: Variation of COD (mg/l) over time at different sampling points
0
20
40
60
80
100
120
140
160
April May June July
COD(mg/l)
Month
0
20
40
60
80
100
120
140
160
1 2 3 4
COD(mg/l)
Sampling Point
April May June July

P a g e | 74
4.2.14 Ammonia (mg/l)
Table 4.14: Ammonia (mg/l) values obtained from test samples
1 5.6 6.8 6.1 7.0
2 7.0 8.1 7.5 8.6
3 11.9 13.1 12.3 14.0
4 7.4 7.8 7.6 9.3
Figure 4.66: Ammonia (mg/l) values at Mogbazar flyover
0
4
8
12
16
20
April May June July
Ammonia(mg/l)
Month

P a g e | 75
Figure 4.67: Ammonia (mg/l) values at Overflow structure
Figure 4.68: Ammonia (mg/l) values at Inlet of Gulshan Lake
0
4
8
12
16
20
April May June July
Ammonia(mg/l)
Month
0
4
8
12
16
20
April May June July
Ammonia(mg/l)
Month

P a g e | 76
Figure 4.69: Ammonia (mg/l) values behind Sonargaon hotel
The Seasonal Variation of the Color (Pt-Co) can be represented as below:
Figure 4.70: Variation of Ammonia (mg/l) over time at different sampling points
0
4
8
12
16
20
April May June July
Ammonia(mg/l)
Month
0
4
8
12
16
20
1 2 3 4
Ammonia(mg/l)
Sampling Point
April May June July

P a g e | 77
4.2.15 Biochemical Oxygen Demand (BOD (mg/l)
Table 4.15: BOD5 (mg/l) values obtained from test samples
1 14.2 20 33.1 55.1
2 6.2 8.0 6.1 18.9
3 16.2 22 21.1 43.1
4 8.2 12 19.1 29.1
Figure 4.71: BOD5 (mg/l) values at Mogbazar flyover
0
10
20
30
40
50
60
April May June July
BOD5(mg/l)
Month

P a g e | 78
Figure 4.72: BOD5 (mg/l) values at Overflow structure
Figure 4.73: BOD5 (mg/l) values at Inlet of Gulshan Lake
0
10
20
30
40
50
60
April May June July
BOD5(mg/l)
Month
0
10
20
30
40
50
60
April May June July
BOD5(mg/l)
Month

P a g e | 79
Figure 4.74: BOD5 (mg/l) values behind Sonargaon hotel
The Seasonal Variation of the BOD5 (mg/l) can be represented as below:
Figure 4.75: Variation of BOD5 (mg/l) over time at different sampling points
0
10
20
30
40
50
60
April May June July
BOD5(mg/l)
Month
0
10
20
30
40
50
60
1 2 3 4
Phosphate(mg/l)
Sampling Point
April May June July

P a g e | 80
4.3 Discussion
4.3.1 Discussion of Dhanmondi Lake
By testing existing water from different sources we have pH value from 6.67 to 7.41
whereas the standard range as ECR’97 is 6.5 to 8.5.So, the pH value is 100% satisfied. The
alkalinity of the lake water decreases gradually with the advancement of the rainy season.
Thus the water of the lake is slightly acidic in nature.
The value of color of the existing water ranges from 5 to 48 Pt-Co unit whereas ECR.97
standard range is 15 Pt-Co unit, so the color is very much higher than the permissible limit.
The seasonal variation graph shows that the value of color decreases with the advancement
of rainy season.
The average value of the turbidity is 5 NTU which is within the permissible limit according
to ECR’97(10 NTU).This means there is less suspended particles or colloids in the water
of the lake.
From the data of the test of NH3-N we found that there is much variation in the values for
different sources. They vary from 0.375 to 18.25 (mg/L). The values of NH3-N obtained
from Robindroshorobor satisfies both Bangladesh standard (0.5mg/L) and WHO standard
(1.5mg/L) but the concentration of NH3-N in all other sampling points were much higher
than the permissible limit. Therefore it is a great concern to lower the value of ammonia to
prevent lower reproduction and growth, or death of organisms.
The average value of Phosphate (𝑃𝑂4 𝑎𝑠 𝑃) concentration is 0.13(𝑚𝑔/L) which is within
the range of 6 (𝑚𝑔/L) according to ECR’97.The value of phosphate was found highest in
all four months for the sample collected near Jahaj Bari.
Average 𝐶𝑂𝐷 value of the lake water is 20 (𝑚𝑔/L) varying from 5 (mg/L) to 55 (mg/L)
which is much higher than the standard limit for drinking water (4.0 𝑚𝑔/L) according to
ECR’97.The standard permissible limit of COD value for surface water is 50 (mg/L) which
makes it useable for domestic purposes only prohibiting its uses as potable water source.
The major contributor for high 𝐶𝑂𝐷 value we can see from the data is at Robindroshorobor
demanding special investigation for future treatment process.

P a g e | 81
By testing existing water we have found that BOD5 values varying from 1 to 10 mg/L
whereas ECR.97 standard range is 0.2 mg/L. So, BOD5 value is very high and not
recommended for drinking purposes. The seasonal variation shows that the deviation of
BOD5 near Jahaj Bari is high but it is more or less consistent in all other three sample
sources. Besides from the obtained data we have observed that the value of BOD5 is highest
in 3rd
sample location (behind the slum) because of the greater disposal of domestic
wastage and human excreta. Since the average BOD5 value of the existing water (3.6 mg/L)
exceeds the limit set by DoE (2ppm) for surviving of aquatic microbes, it is highly
recommended to reduce BOD5 to support aquatic life.
All the analysis stated above obtained from the lake’s representative samples clearly
denotes the pollution status of Dhanmondi Lake.
4.3.2 Discussion of Hatirjheel Lake
The pH value of the lake varies from 6.6 to 7.7. The standard range as ECR’97 is 6.5 to
8.5. So, it satisfies the standard value. The lake water was alkaline in the month of April
and May but then the pH started decreasing and the water became acidic, pH decreased
because of the change in weather conditions. As water becomes acidic during rainy season,
so the pH decreased during the month of June and July.
The minimum limit of DO is 6.0 mg/l, the DO values of lake observed during experiments
varies from 8.62 mg/l to 12.6 mg/l. The observed values of DO are well above the minimum
limit which indicates that DO available in lake water is sufficient for the microorganisms.
The DO values increased over the time duration from April to July. This increase in DO
occurred due to drop in temperature, as the temperature decreased gradually from April to
July.
The average value of Turbidity observed is 33.4 NTU which is more than three times the
permissible limit according to ECR’97 (10 NTU). This could be due to the suspended
matter like clay, colloidal particles and other organisms present in water. Moreover the

P a g e | 82
turbidity of water decreased over the time duration from April to July. The decrease in
turbidity occurred due to the increase in rainfall.
All the data obtained for the test of Ammonia (𝑁𝐻3−𝑁) show a huge concentration. They
vary between 5.6 to 14 𝑚𝑔𝐿⁄. Surely they are above both Bangladesh standard (0.5 𝑚𝑔𝐿⁄)
and WHO guideline value (1.5 𝑚𝑔𝐿⁄). So, it is a great concern to remove (at least lower)
the Ammonia concentration. It can cause lower reproduction and growth, or death of
organisms. The samples collected at inlet of Gulshan lake show relatively higher
concentration of Ammonia than the other locations.
The average value of Phosphate (𝑃𝑂4 𝑎𝑠 𝑃) concentration is 0.23 𝑚𝑔𝐿⁄ which is well below
the range of 6 𝑚𝑔𝐿⁄ according to ECR’97. The samples collected in July show higher
concentration of Phosphate as compared to the previous months and the samples collected
in April show lowest Phosphate concentration.
Average 𝐶𝑂𝐷 value of the lake is 88 𝑚𝑔𝐿⁄ which is much higher than the standard limit
for drinking water (4.0 𝑚𝑔𝐿⁄) according to ECR’97. Such a high value indicates presence
of organic pollutant. So, the lake can be strictly prohibited as potable water source. The
major contributor for high 𝐶𝑂𝐷 value we can see from the data is at Mogbazar flyover and
at Inlet of Gulshan Lake. So, special consideration should be taken during any treatment
measures.
Average 𝐵𝑂𝐷5 value of the lake water is 20.8 𝑚𝑔𝐿⁄, where permissible value for drinking
water is 0.2 𝑚𝑔𝐿⁄. So, the source is not recommended for drinking purpose. The seasonal
variation for the month of July was abrupt, BOD5 increased tremendously while for the rest
of three months the variation of the BOD5 was more or less consistent and the change
(increase or decrease) was not abrupt.
All the analysis stated above obtained from the lake’s representative samples clearly
denotes the severe pollution status of Hatirjheel Lake.

P a g e | 83
Chapter 5
CONCLUSION AND
RECOMMENDATION

P a g e | 84
5 Conclusions & Recommendations
5.1 Conclusion
Dhanmondi and Hatirjheel Lakes are precious assets of Dhaka city with unique regional
characteristics. Apart from their scenic beauty, they have great economical and
environmental value. During extremely dry seasons, the lakes retain considerable amount
of water. These water bodies account for fisheries and provide a habitat for a wide variety
of aquatic vegetation and birds. In the past, the different parts of the Dhanmondi and
Hatirjheel lakes have been drained through engineering interventions and turned into land
for meeting growing housing and transportation demand of the locality. The adverse effects
of such interventions have been deleterious to the environment. They have destroyed the
fish and aquatic vegetables that thrive in the lake. They have also blocked the natural flow
of water. In order to assist the natural processes of groundwater recharge, maintenance of
aquatic life and ecological balance and for turning the lakes and surrounding areas into
recreational places, planned development of the lakes is very much essential.
Saving the lakes from the pollution should be a priority concerns for the sake of
environment. Awareness program is necessary to stop unauthorized activities that seriously
lead to pollution of the lakes and surrounding environment. Our lack of knowledge about
environmental management and indifferent attitude towards protection of the environment
have turned these beautiful water body into a sink of pollution, receiving numerous
unauthorized sewage outlets, surface run-off, urban drainage discharges and even solid
waste from various sources. These practices have caused enormous harm to the lake's
environment and its subsequent degradation in many ways. A coordinated plan for both
Dhanmondi and Hatirjheel lakes should be taken as considering the ecology of the lakes,
the causes of natural and cultural water quality problems, the reasons for lake water
pollution, the techniques for restoring and protecting lakes, the legal issues, the financial
realities for taking some initiatives which require financial allocation and availability of
resources

P a g e | 85
5.2 Recommendations
 Identifying new toxic substances, and implementing pollution prevention and
control strategies.
 Preventing and controlling harmful discharge.
 Necessity of reusing of surface water for sustainable development.
 Preventing environmental threats before they turn into actual problems.
 Developing water quality and ecosystem health objectives.
 Increased awareness of the importance and fragility of freshwater resources.
 To observe the seasonal variation of different parameters to know the worst
condition of the lake.
 Developing public concern regarding environmental abuse.

P a g e | 86
References
A. M. A., Lab manual of Environmental Sessional I, CE 332, BUET.
Mitra S. & Habib A. (2016), Assessment of water quality and pollution sources of
Hatirjheel Lake (B.Sc. Thesis). Retrieved from Civil Engineering Library, BUET
Chowdhury M. & Muntasir S.Y. (2012), Pollution Scenario of Dhaka city lakes: A
case study of Dhanmondi and Ramna Lakes. Global Engineers and
TechnologistsReview, Vol.2 No.7 pp 1-6.
Ahmed M. F. and Rahman M. M., (2010), Water Supply and Sanitation. ITN-
Bangladesh. ISBN: 984-31-0936-8.
Ahmed M. (2013). Water Quality and Pollution Sources of Gulshan Lake.
International Journal of Information Technology and Business
Management, Vol.16 No.1. ISSN 2304-0777.
Alam M. S. (2014). Assessment of Water Quality of Hatirjheel Lake in Dhaka City.
International Journal of Technology Enhancements and Emerging
Engineering Research, Vol. 2, Issue 6. ISSN 2347-4289.
APHA, (1998), Standard Methods for Examination of Water and Wastewater,
20th Edn., American Public Health Association, Washington, DC, New York.
Atauzzaman M. (2015). Assessment of the impact of Overflows from Special
Sewage Diversion Structures on the Water Quality of Hatirjheel.
Retrieved from Civil Engineering Library, BUET.
Background | Hatirjheel. Retrieved February 20, 2016, from
http://www.hatirjheel.org/background/
Chhatwal, R.J., (2011), ―Environment Sciences- A Systematic Approach, 2nd Ed.,
UDH Publishers and Distributors (P) Ltd., pp 104-105.
Environmental Conservation Rules-1997, Bangladesh Gazette, Ministry of
Environment and Forests, Govt. of People’s Republic of Bangladesh, 27th
August, 1997.
Faith Ngwenya, (2006). Water Quality Trends in the Eerste River, Western Cape,
1990-2005. A mini thesis submitted in partial fulfillment of the
requirements for the degree of Magister Scientiae, Integrated Water
Resources Management in the Faculty of Natural Science, University of
Western Cape. pp. 41

P a g e | 87
Hach, C.C., Klein, R.L. Jr. & Gibbs, C.R., (1997), Introduction to Biochemical
Oxygen Demand; Technical Information Series. Booklet No. 7. Hach
Company, U.S.A.
Islam et al. (2015). Investigation of Water Quality Parameters from Ramna,
Crescent and Hatirjheel Lakes in Dhaka City. Journal of Environmental Science &
Natural Resources, 8(1): 1-5, 2015. ISSN 1999-7361.
Sabit M. I. (2011). Evaluation of Water Quality and Pollution Sources of Gulshan
Lake (M.Sc. Thesis). Retrieved from Civil Engineering Library, BUET.

Identification of Pollution Sources & Water Quality Analysis of Dhanmondi & Hatirjheel Lake

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Identification of Pollution Sources & Water Quality Analysis of Dhanmondi & Hatirjheel Lake

Similar to Identification of Pollution Sources & Water Quality Analysis of Dhanmondi & Hatirjheel Lake (20)

Recently uploaded

Recently uploaded (20)

Identification of Pollution Sources & Water Quality Analysis of Dhanmondi & Hatirjheel Lake